Alireza Pendashteh | UPM - Universiti Putra Malaysia (original) (raw)

Books by Alireza Pendashteh

Research paper thumbnail of A. Fakhru’l-Razi and A. Pendashteh, Passive and active treatment technologies for oil and gas produced water, chapter 2, J. Bhattacharya (ed.), In Project Environmental Clearance: Engineering and Management Aspects, Wide Publishing, 2010, Kolkata, India.

Papers by Alireza Pendashteh

Research paper thumbnail of Application of isolated halophilic microorganisms suspended and immobilized on walnut shell as biocarrier for treatment of oilfield produced water

Journal of Hazardous Materials, 2020

Salinity expressed as total dissolved solids (TDS), is the most challenging parameter in bioremed... more Salinity expressed as total dissolved solids (TDS), is the most challenging parameter in bioremediation of produced water which may inhibit the microbial activities and cause sedimentation problems. The present study explores the feasibility of using walnut shell as an inexpensive and accessible adsorbent-carrier for the immobilization of isolated halophilic microorganisms for treatment of synthetic oilfield produced water. The moving bed biofilm reactor (MBBR) was examined with influent chemical oxygen demand (COD) concentrations from 900 to 3600 mg L −1 , TDS concentrations from 35,000-200,000 mg L −1 , and cycle times from 24 to 72 h. Comparison of the MBBR with the conventional sequencing batch reactor (SBR) indicated that both systems operated at lower influent COD and TDS concentrations satisfactorily; but at higher TDSs (above 150,000 mg L −1) the MBBR was more resistant to the shocks of toxicity (salinity) and organic load relative to the SBR. Also, the effluent turbidity was lower and the free sludge settling property was more favorable in the MBBR with average sludge volume index (SVI) of 38.8 mL g −1 compared to the SBR with SVI of 98.09 mL g −1. Microbial identification confirmed the presence of eight dominant halophilic species which were hydrocarbon degraders and/or denitrifiers.

Research paper thumbnail of Biak, DRA; Madaeni, SS; Abidin, ZZ Review of technologies for oil and gas produced water treatment

Research paper thumbnail of Treatment of high saline textile wastewater by activated sludge microorganisms

Journal of Applied Research and Technology, 2017

Textile wastewater is a combination of various chemicals and different types of dyes and has a sa... more Textile wastewater is a combination of various chemicals and different types of dyes and has a salty nature. In this study, an SBR (sequencing batch reactor) was used to treat synthetic and real textile wastewaters in a 24 h cycle time. Remazol Brilliant Blue R, a reactive dye, was used as the model dye. Dye concentrations ranged from 125 mg/L to 500 mg/L, and TDS (total dissolved solids) concentrations ranged from 1000 mg/L to 10,000 mg/L in synthetic wastewaters. For the highest dye concentration (500 mg/L) with low TDS, an 80.71% COD removal efficiency was obtained; at a TDS concentration of 5000 mg/L, a 59.44% COD removal efficiency was obtained. When the TDS concentration of wastewater was raised to 10,000 mg/L, COD removal decreased to 14.92% and reductions in MLSS (mixed liquor suspended solids) and MLVSS (mixed liquor volatile suspended solids) concentrations were observed. According to the results, increasing the TDS concentration of wastewater up to 5000 mg/L did not affect COD removal efficiency of the activated sludge microorganisms in the treatment system.

Research paper thumbnail of Optimized Removal of Sodium Dodecylbenzenesulfonate by Fenton-Like Oxidation Using Response Surface Methodology

Iranian Journal of Chemistry & Chemical Engineering-international English Edition, Dec 1, 2016

This study investigates the degradation of sodium dodecylbenzenesulfonate (SDBS) in aqueous solut... more This study investigates the degradation of sodium dodecylbenzenesulfonate (SDBS) in aqueous solution by Fenton-like oxidation process. The effects of different parameters such as concentrations of ferric chloride and hydrogen peroxide, pH and reaction time on the SDBS removal and Chemical Oxygen Demand (COD) reduction were evaluated. Response Surface Methodology (RSM) with Central Composite Design (CCD) was used to study and optimize the oxidation process. A quadratic polynomial equation could accurately model the SDBS removal with an R 2 of 0.98. The results showed that pH and time were the most significant parameters affecting SDBS removal and COD reduction, respectively. A high SDBS (90.5%) and COD (70.7%) reduction efficiency was obtained at the optimal conditions of 60 min, pH 4 and 8.82 mM of H2O2 and 3.67mM of Fe +3. In this work, the effects of some organic compounds on the degradation of SDBS by Fenton-like process were examined. The results showed that 50 mgL-1 of oxalic acid slightly enhanced the SDBS degradation efficiency while acetic acid and Ethylenediaminetetraacetic acid (EDTA) reduced it.

Research paper thumbnail of Electro-activated persulfate oxidation (EC/PS) for the treatment of real oilfield produced water: Optimization, developed numerical kinetic model, and comparison with thermal/EC/PS and EC systems

Process Safety and Environmental Protection, 2021

Abstract In this study, the performance and efficiency of electrocoagulation (EC), electro-activa... more Abstract In this study, the performance and efficiency of electrocoagulation (EC), electro-activation of persulfate (EC/PS), and thermal activated-EC/PS for the treatment of two real produced water (PW) samples using iron electrodes were studied. To optimize and find out the effect of operating conditions on the different responses for EC and EC/PS, response surface methodology (RSM) was implemented. The results showed that EC process had considerable performance in the removal of H2S (96 %), oil and grease (O&G) (98–99 %), turbidity (91–97 %), phosphate phosphors (94 %), and heavy metals (92 %). EC/PS was introduced as an effective and a compact method for the removal of soluble hydrocarbons and nitrogen-ammonium (N-NH4+). The results indicated that at the current density of 35 A/m2, PS of 30 mM, reaction time of 30 min, N-NH4+ and chemical oxygen demand (COD) removal efficiency increased to 37 % and 71–94 %, respectively. To further increase the ammonia removal, EC/PS was integrated into thermal-PS activation at 65 °C, and the results showed that the ammonia removal by thermal/EC/PS reached about 69 %. According to gas chromatography/mass spectrometry (GC/MS), EC/PS was able to effectively eliminate most of the hydrocarbons. Moreover, a new kinetic model based on a novel algorithm and the main reactions occurring during EC/PS was developed to predict the COD removal efficiency, and the results indicated that it could predict COD removal efficiency with the acceptable accuracy. The estimated operating costs and energy consumption for EC/PS demonstrated that this process was more economical and efficient than other advanced oxidation processes (AOPs).

Research paper thumbnail of Advanced oxidation process as a green technology for dyes removal from wastewater: A review

Iranian Journal of Chemistry & Chemical Engineering-international English Edition, 2020

The combination of green chemistry and green engineering is needed for the production of minimum ... more The combination of green chemistry and green engineering is needed for the production of minimum waste, renewable sources, an increasing utilization of raw materials, use of simpler and safer products, and novel technologies. The use of novel cleaner technologies lead to effective productions in chemical industries. The dyes involve the complex structure, recalcitrant nature, and more intermediates. The generation of oxidative species with higher yields is obtained by advanced oxidation processes as a green and powerful treatment technology. These processes are the effective, inexpensive and eco-friendly methods for decaying the toxic pollutants. The AOPs are classified as non-photochemical and photochemical processes. There are included various technologies such as ozonation, Fenton oxidation, wet air oxidation, electrochemical oxidation and photocatalytic oxidation. The production of highly reactive free radicals is the main purpose of the AOPs process. The generation of free radi...

Research paper thumbnail of Removing Iron, Manganese and Ammonium Ions from Water Using Greensand in Fluidized Bed Process

Journal of Water Process Engineering, 2021

Natural minerals are used as sorbent in water treatment processes due to their high exchange and ... more Natural minerals are used as sorbent in water treatment processes due to their high exchange and relatively low cost. In this paper, a pilot water treatment was conducted to explore the application of greensand in a fluidized bed column while the iron, manganese and ammonium removal performances of two treatment processes, including greensand filtration and potassium permanganate-greensand filtration were evaluated. The breakthrough curves were investigated to analyze the effect of variables such as bed height and inlet flow on the removal performance in addition to the physical properties of greensand. The results showed that the effect of potassium permanganate on the outlet concentration of the fluidized bed was significant in terms of the breakthrough curves which led to the breakthrough points for iron and manganese. It was found that adding potassium permanganate increased the equilibrium column capacity (q eq) from 5.18 mg/g and 2.16 mg/g to 12.70 mg/g and 11.29 mg/g for iron and manganese respectively. So Fe and Mn outlet concentrations reached under the admissible maximum concentration of drinking water. In the experiments without KMnO 4 , iron removal was found to be caused by reductive dissolution and adsorption while adsorption was the only mechanism for manganese removal. The findings indicated that ammonium removal was minimally influenced by KMnO 4 and ion exchange was the main mechanism for ammonium removal.

Research paper thumbnail of Estimation of effluent parameters of slaughterhouse wastewater treatment with artificial neural network and B-spline quasi interpolation

International Journal of Environmental Research, 2020

Effluent of slaughterhouse wastewater treatment by combined up-flow anaerobic sludge blanket (UAS... more Effluent of slaughterhouse wastewater treatment by combined up-flow anaerobic sludge blanket (UASB) reactor and extended aeration reactor was estimated through artificial neural networks (ANN), ANN-genetic algorithm (GA) and B-spline quasi interpolation. The overall system operated at two runs with average total chemical oxygen demand (TCOD) of 1514.65 and 3160.2 mg/L for the first and second run, respectively; with two overall hydraulic retention times of 73 and 104 h for each run. The overall system could remove TCOD, ammonia, phosphate and turbidity to a high extent. The multilayer perceptron artificial neural network (MLPANN) trained by Levenberge-Marquardt algorithm was employed to predict the TCOD, ammonia, phosphate and turbidity of the effluent which resulted in R of 0.8257, 0.6274, 0.7961 and 0.6884, respectively. The optimization of MLPANN by GA performed better than MLPANN with R of 0.8390, 0.7650, 0.8107 and 0.7365 for TCOD, ammonia, phosphate and turbidity, respectively. The B-spline quasi interpolation indicates a more accurate prediction due to its R of 0.9619, 0.8806, 0.8307 and 0.7856 for TCOD, ammonia, phosphate and turbidity, respectively. The B-spline quasi interpolation operation time is notably lower than ANN and ANN-GA. In addition, it has a simple algorithm and is implemented easier than the artificial neural network model. Article Highlights • Slaughterhouse wastewater treatment by combined biological process. • Multi-layer perceptron, genetic algorithm and B-spline quasi interpolation were used for prediction. • Prediction of total COD, ammonia, phosphate and turbidity. • Effect of HRT investigated on removal efficiency.

Research paper thumbnail of Treatment of wood industry wastewater by combined coagulation–flocculation–decantation and fenton process

Water Environment Research, 2020

In the present research, the efficiency of turbidity and chemical oxygen demand (COD) reduction f... more In the present research, the efficiency of turbidity and chemical oxygen demand (COD) reduction from the wood industry wastewater (WIW) by the use of a combined coagulation-flocculationdecantation (CFD)-Fenton process was studied. Firstly, the performance of three coagulants such as ferric chloride (FeCl 3), aluminum sulfate (alum), and poly-aluminum chloride (PACl) was evaluated. The polyacrylamide (PAM) was used as a flocculant. The results showed that the polyaluminum chloride had a high removal efficiency. The COD reduction of 84.1% and turbidity removal of 82.0% of were obtained in coagulation-flocculation-decantation (CFD). Secondly, Fenton process was optimized, by the use of a response surface methodology (RSM), with application of a central composite design (CCD). The maximum turbidity and COD removal obtained by this process were 94.1 and 72.5% respectively, under optimal conditions ([Fe 2+ ] = 250 mg/L, [H 2 O 2 ] = 500 mg/L, pH 3.5, time 60 min). The kinetics of COD and turbidity removal were determined by the model of first order. In conclusion, the combination of coagulation-flocculation-Accepted Article This article is protected by copyright. All rights reserved decantation (CFD)-Fenton process presented as a remarkable method for wood wastewater treatment.

Research paper thumbnail of Saline oily wastewater treatment using Lallemantia mucilage as a natural coagulant: Kinetic study, process optimization, and modeling

Industrial Crops and Products, 2021

Abstract Saline oily wastewater is among the greatest environmental issues that requires effectiv... more Abstract Saline oily wastewater is among the greatest environmental issues that requires effective treatment methods. The new trend of using natural coagulants to treat saline oily wastewater can help overcome the drawbacks of inorganic coagulants such as high costs, health risk, and large amounts of sludge. In the present study, the Lallemantia mucilage was used for the first time as a novel natural coagulant, which offered a remarkable performance in bilge water treatment at the optimum condition of coagulants dose = 10 mg/L, pH = 7.00, and contact time = 23.8 min with the maximum chemical oxygen demand (COD) removal efficiency of 87.57 % and influent COD of 1202.5 ± 8.5 mg/L. Also, at the optimum condition, Lallemantia mucilage could remove surfactant up to 20.6 % with influent concentration of 55 ± 0.4 mg/L. A quadratic polynomial with R2 = 0.9943 for COD removal showed a satisfactory fit and consistency. The predictability of Multivariate Adaptive Regression Splines (MARS) method with R 2 = 0.95235 was significant compared to the Response Surface Methodology (RSM) with R 2 = 0.9599. The second-order kinetic equation performed better in terms of kinetic determination with k = 0.00009, E = 1.42776E+13, and R 2 = 0.9642 than the first-order model with k = 0.0159, E = 2.52237E+15, and R 2 = 0.9431.

Research paper thumbnail of Removal of TCOD and phosphate from slaughterhouse wastewater using Fenton as a post-treatment of an UASB reactor

Journal of Environmental Health Science and Engineering, 2020

A pilot was designed to study the removal efficiencies of total chemical oxygen demand (TCOD) and... more A pilot was designed to study the removal efficiencies of total chemical oxygen demand (TCOD) and phosphate by a combined biological and chemical method. Two stages of Up-flow anaerobic sludge blanket (UASB) reactor and advanced oxidation processes was operated in batch mode. The UASB reactor was operated with hydraulic retention time of 26 h. UASB removal efficiency of TCOD and phosphate were 62.2 and 36.5%, respectively. Fenton process was used as a post-treatment so as to remove organic matter and nutrients. At this stage, the removal efficiencies of TCOD and phosphate were investigated considering the effect of parameters such as pH, hydrogen peroxide and Fe (II) dose based on Taguchi experimental design. Accordingly, under optimum conditions, pH = 3, 1000 mg/l of H 2 O 2 and 400 mg/l of Fe (II) the removal efficiencies of TCOD and phosphate reached 95.41 and 85.29%, respectively. The combined method removed TCOD and phosphate up to 98.6 and 90.5%, respectively.

Research paper thumbnail of Sulphate radical-based advanced oxidation technologies for removal of COD and ammonia from hazardous landfill leachate: A review

International Journal of Environmental Analytical Chemistry, 2021

Research paper thumbnail of Advanced numerical kinetic model for predicting COD removal and optimisation of pulp and paper wastewater treatment by Fenton process

International Journal of Environmental Analytical Chemistry, 2020

In the present study, a kinetic model has been developed to predict the chemical oxygen demand (C... more In the present study, a kinetic model has been developed to predict the chemical oxygen demand (COD) removal efficiency of Fenton process for the treatment of pulp and paper mill (P&P) wastewater. In order to investigate the effects of main parameters including Fe (II) dosage, H 2 O 2 dosage, and pH, 45 experiments have been carried out at three levels for each parameter, and thus COD removal efficiency has been obtained. The Fenton process was simulated by using 10main reactions, and the model was solved numerically according to a specific algorithm. All the pollutants in the P&P wastewater were assumed to be a pseudo-material, andapparent kinetic constant (k**)was calculated using a developed iterative method. The results of the numerical model indicated that the proposed model had a great potential to predict COD removal efficiency for P&P wastewater by Fenton in comparison to the first and second-order kinetic models. Accordingly, R-squared (R 2), Root Mean Square Error (RMSE), and Mean Relative Error (MRE) of the numerical kinetic model were 0.93, 4.296 × 10 −7 , and 0.035, respectively, implying remarkable accuracy of the numerical model. Furthermore, at the optimum point of Fenton process,which was pH: 3,[H 2 O 2 ]:0.015 Molar, and [Fe(II)]: 0.015 Molar, the COD removal efficiency of P&P wastewater reached 78%. As the basis of the numerical model was established according to mechanisms of Fenton process, the results demonstrated the great performance of the advanced kinetic model in the estimation of the COD removal efficiency, the behaviour of effective parameters such as pH, H 2 O 2 , and Fe(II) along with their effects on k**, and Fe(III) accumulation during Fenton process.

Research paper thumbnail of Evaluation of COD removal by biologically GSBR from photocatalytically pre-treated oilfield produced water

DESALINATION AND WATER TREATMENT, 2020

Today combined photo-assisted advanced oxidation process (AOP) and biological processes are gaini... more Today combined photo-assisted advanced oxidation process (AOP) and biological processes are gaining in importance as treatment systems. The use of AOPs as a pretreatment step to enhance the biodegradability of produced water (PW) can be justified if the resulting intermediates are readily degradable by microorganisms in further biological treatment. Therefore, investigating the relationshipbetweenadvancedoxidationpretreatedeffluentandsubsequentbioreactorperformance can help to optimize these systems. In this study, an integrated solar photoreactor-granular bioreactorwasusedtotreatsyntheticandrealproducedwater.Solarphotoreactorwasdesignedand optimized using a cascade falling film theory and TiO 2 /SnO 2 /CuO photocatalyst supported on the Scoria-concrete surface. The effects of various operational parameters on the photocatalytic process wereinvestigatedusingresponsesurfacemethodology(RSM).Optimumbiochemicaloxygendemand (BOD 5)/chemical oxygen demand (COD) ratio of 0.40 was achieved at pH of 6.5, a photocatalyst concentrationof60gL-1 ,temperatureof40°C,lightexposuretimeof70minandH 2 O 2 concentration of2.5mM.PhotoreactoreffluentwithCODandBODof1,042±10and432±4wasfedintotheaerobic granularbioreactor,respectively.TheremovedCODbythebiologicaltreatmentwas50%,whereasby thecombinedphotocatalytic-biologicaltreatmentitwasreachedto94%.Inthecaseofrealproduced water,theremovalefficiencywasdecreasedto92%.Granulestructurewasdeterminedusingscanning electron microscopy. The combined biological-photocatalytic treatment significantly shortened the degradation and mineralization time of the biological treatment.

Research paper thumbnail of Effects of Various Plants on Treatment Efficiency of Horizontal Subsurface Flow Constructed Wetlands Based on the Hydraulic Retention Time

Environmental Engineering and Management Journal, 2019

In this study the effectiveness of Lactuca sativa, Medicago sativa and Phragmites australis for t... more In this study the effectiveness of Lactuca sativa, Medicago sativa and Phragmites australis for the treatment of domestic wastewater in horizontal subsurface flow was investigated. The removal efficiency of chemical oxygen demand (COD), total nitrogen (TKN), total phosphorus (TP), and total suspended solids (TSS) was measured. The experiment was conducted in two different retention time (5 and 7 days) in three seasons (spring, summer and fall). The removal efficiency was increased as the retention time increased. Based on the results, M. sativa had the highest removal efficiency of COD (90.7%), TSS (87.8%) and TKN (59%) in 7 days HRT. Meanwhile, P. australis removed (67%) TP during 7 days HRT from wastewater. Seasonal changes showed different effects on removal rate and L. sativa showed lower removal efficiency in compare to other two plants.

Research paper thumbnail of Biological treatment of slaughterhouse wastewater: kinetic modeling and prediction of effluent

Journal of Environmental Health Science and Engineering, 2019

In this study three modeling approaches consisting Modified Stover-Kincannon, multilayer perceptr... more In this study three modeling approaches consisting Modified Stover-Kincannon, multilayer perceptron neural network (MLPANN) and B-Spline quasi interpolation were applied in order to predict effluent of up-flow anaerobic sludge blanket (UASB) reactor and also to find the reaction kinetics. At first run, the average total chemical oxygen demand (TCOD) removal efficiency was 48.3% with hydraulic retention time (HRT) of 26 h and 63.8% with HRT of 37 h, at OLR of 0.77-1.66 kg TCOD/m 3 d. At the second run, UASB reactor operated with OLR of 1.94-3.1 kg TCOD/m 3 d and achieved the average TCOD removal efficiency of 64.74 and 72.48% with HRT of 26 and 37 h, respectively. The Modified Stover-Kincannon performed well in terms of kinetic determination with a high value of regression coefficient over 0.98. The B-Spline quasi interpolation and MLPANN indicated a great fit for effluent prediction with average R of 0.9984 and 0.9986, and MSE of 157.6050 and 129.7796, respectively; however, they gave no information about reactions occurred in the system. Keywords Biological treatment. TCOD removal. Modified Stover-Kincannon. Artificial neural network. B-spline quasi interpolation Highlights • Performance of up-flow anaerobic sludge blanket reactor. • Effect of HRT on removal efficiency. • Multi-layer perceptron and B-Spline quasi interpolation were used in order to predict the effluent of UASB reactor. • Kinetic modeling of UASB reactor by modified Stover-Kincannon.

Research paper thumbnail of Evaluation of COD and turbidity removal from woodchips wastewater using biologically sequenced batch reactor

Process Safety and Environmental Protection, 2019

Highlights  The SBR process is introduced as an efficient method for woodchips wastewater treatm... more Highlights  The SBR process is introduced as an efficient method for woodchips wastewater treatment•  The high efficiency of SBR indicates that woodchips can act as an auxiliary carbon source for microbial respiration in this process•  The best performance of this process is that the COD concentration will be obtained according to the standard limit of Iran (<100) without using chemical processes• ABSTRACT: The wood industry consumes a lot of water. Due to the reduction of water resources in the world, the treatment of this contaminated water is very essential. In this study, the removal efficiencies of the chemical oxygen demand (COD) and turbidity from woodchips wastewater with the use of a sequencing batch reactor (SBR) were studied at a bench scale. Woodchips wastewater samples were collected with a COD of 1300 mg L-1 and a turbidity of 93 NTU. The optimization of the SBR process was investigated by response surface methodology (RSM) based on a central composite design (CCD). A quadratic polynomial model was fit to the data with R 2 of 0.9919 for COD reduction, R 2 of 0.9910 for turbidity removal, and R 2 of 0.9945 for sludge volume Index (SVI), respectively. The effect of three parameters, including initial COD, mixed liquor suspended solids (MLSS), and Hydraulic retention time (HRT) on the COD reduction and turbidity removal were evaluated. The initial COD (A), MLSS (B), cycle time (C), AB, AC, BC, A 2 , B 2 , and C 2 were considered as the affective parameters in the COD reduction. Initial COD (A), MLSS (B), A 2 , B 2 , C 2 , AC, and BC were observed as the remarkable model terms on the turbidity removal. Also, initial COD (A), MLSS (B), cycle time (C), B 2 , C 2 , and BC were the significant model factors in SVI index. At optimal conditions, involving an initial COD of 1000 mg L-1 , an organic loading rate (OLR) of 0.450 kg COD/m 3 d, MLSS of 3000 mg L-1 , and cycle time of 24 h, we observed 94.6% of COD reduction, 98.5% turbidity removal, and 79 mL g-1 SVI. The results also showed that the kinetic of COD reduction and turbidity removal could be represented by the pseudo-second-order model.

Research paper thumbnail of Treatment of pulp and paper wastewater by lab-scale coagulation/SR-AOPs/ultrafiltration process: optimization by Taguchi

DESALINATION AND WATER TREATMENT, 2017

In this study, the treatment of pulp and paper wastewater using combined approach of coagulation/... more In this study, the treatment of pulp and paper wastewater using combined approach of coagulation/ sulfate radical-advanced oxidation process (SR-AOPs)/ultrafiltration (UF) was studied in the lab scale. In the beginning of this system, the performance of three coagulants such as polyaluminum chloride (PACl), ferric chloride (FeCl 3) and alum was evaluated to achieve high recycled fiber. According to the results yielded, the FeCl 3 , with high fiber recycling (98%) and removal efficiency, was more efficacious. In the next step, the potassium persulfate (PPS)-Fe(II) and PPS-Fe(III) efficiency in the removal of the chemical oxygen demand (COD), aromatic compounds (UV 254) and the value of sludge volume index were evaluated using Taguchi design of the experiment. The results showed that the removal efficiency of COD and UV 254 in the process of PPS-Fe(II) was 92.6% and 95.8% which had the better performance than the process of PPS-Fe(III). The results showed that electrical conductivity (EC) in coagulation/SR-AOPs had increased to 30.64%. Moreover, there was a significant amount of sulfate in the effluent; whereas, UF was applied. Accordingly, using UF after pretreatment by coagulation/PPS-Fe(II), the removal efficiency of sulfate, EC, COD and UV 254 increased to 99.44%, 62.05%, 97.35% and 98.75%, respectively.

Research paper thumbnail of Combined Fenton-like oxidation and aerobic MBBR biological processes for treatment of the wastewater of detergent industries

DESALINATION AND WATER TREATMENT, 2017

Surfactant is one of the most important compounds widely used in the formulation and structure of... more Surfactant is one of the most important compounds widely used in the formulation and structure of detergents all over the world. In this study, we investigated the combined Fenton-like oxidation and aerobic moving bed biofilm reactor (MBBR) biological processes for treatment of the wastewater of detergent industries. The average chemical oxygen demand (COD) and linear alkylbenzene sulfonate (LAS) in the raw wastewater were 24,039 and 210 mg/L, respectively. The maximum removal efficiencies of the pretreatment and Fenton-like oxidation process for COD and LAS were 95% and 90%, respectively, and the effluent concentrations of COD and LAS were about 1,250 and 100 mg/L, respectively. For MBBR process, in reactor 1 (with lower LAS concentrations) with 36 h hydraulic retention time (HRT), the maximum removal efficiencies were found to be 94.20% and 99.99% for the influent COD and LAS, respectively (R 2 = 0.93 and p < 0.05 and R 2 = 0.92 and p < 0.05). Also, for reactor 2 (with higher LAS concentrations), in the same condition with 36 h HRT, the maximum removal efficiencies were 93.41% and 95% for the influent COD and LAS, respectively (R 2 = 0.92 and p < 0.05 and R 2 = 0.84 and p < 0.05). This investigation shows that Fenton-like oxidation process, in combination with MBBR process, can provide the local effluent discharge standard for detergent industries.

Research paper thumbnail of Application of isolated halophilic microorganisms suspended and immobilized on walnut shell as biocarrier for treatment of oilfield produced water

Journal of Hazardous Materials, 2020

Salinity expressed as total dissolved solids (TDS), is the most challenging parameter in bioremed... more Salinity expressed as total dissolved solids (TDS), is the most challenging parameter in bioremediation of produced water which may inhibit the microbial activities and cause sedimentation problems. The present study explores the feasibility of using walnut shell as an inexpensive and accessible adsorbent-carrier for the immobilization of isolated halophilic microorganisms for treatment of synthetic oilfield produced water. The moving bed biofilm reactor (MBBR) was examined with influent chemical oxygen demand (COD) concentrations from 900 to 3600 mg L −1 , TDS concentrations from 35,000-200,000 mg L −1 , and cycle times from 24 to 72 h. Comparison of the MBBR with the conventional sequencing batch reactor (SBR) indicated that both systems operated at lower influent COD and TDS concentrations satisfactorily; but at higher TDSs (above 150,000 mg L −1) the MBBR was more resistant to the shocks of toxicity (salinity) and organic load relative to the SBR. Also, the effluent turbidity was lower and the free sludge settling property was more favorable in the MBBR with average sludge volume index (SVI) of 38.8 mL g −1 compared to the SBR with SVI of 98.09 mL g −1. Microbial identification confirmed the presence of eight dominant halophilic species which were hydrocarbon degraders and/or denitrifiers.

Research paper thumbnail of Biak, DRA; Madaeni, SS; Abidin, ZZ Review of technologies for oil and gas produced water treatment

Research paper thumbnail of Treatment of high saline textile wastewater by activated sludge microorganisms

Journal of Applied Research and Technology, 2017

Textile wastewater is a combination of various chemicals and different types of dyes and has a sa... more Textile wastewater is a combination of various chemicals and different types of dyes and has a salty nature. In this study, an SBR (sequencing batch reactor) was used to treat synthetic and real textile wastewaters in a 24 h cycle time. Remazol Brilliant Blue R, a reactive dye, was used as the model dye. Dye concentrations ranged from 125 mg/L to 500 mg/L, and TDS (total dissolved solids) concentrations ranged from 1000 mg/L to 10,000 mg/L in synthetic wastewaters. For the highest dye concentration (500 mg/L) with low TDS, an 80.71% COD removal efficiency was obtained; at a TDS concentration of 5000 mg/L, a 59.44% COD removal efficiency was obtained. When the TDS concentration of wastewater was raised to 10,000 mg/L, COD removal decreased to 14.92% and reductions in MLSS (mixed liquor suspended solids) and MLVSS (mixed liquor volatile suspended solids) concentrations were observed. According to the results, increasing the TDS concentration of wastewater up to 5000 mg/L did not affect COD removal efficiency of the activated sludge microorganisms in the treatment system.

Research paper thumbnail of Optimized Removal of Sodium Dodecylbenzenesulfonate by Fenton-Like Oxidation Using Response Surface Methodology

Iranian Journal of Chemistry & Chemical Engineering-international English Edition, Dec 1, 2016

This study investigates the degradation of sodium dodecylbenzenesulfonate (SDBS) in aqueous solut... more This study investigates the degradation of sodium dodecylbenzenesulfonate (SDBS) in aqueous solution by Fenton-like oxidation process. The effects of different parameters such as concentrations of ferric chloride and hydrogen peroxide, pH and reaction time on the SDBS removal and Chemical Oxygen Demand (COD) reduction were evaluated. Response Surface Methodology (RSM) with Central Composite Design (CCD) was used to study and optimize the oxidation process. A quadratic polynomial equation could accurately model the SDBS removal with an R 2 of 0.98. The results showed that pH and time were the most significant parameters affecting SDBS removal and COD reduction, respectively. A high SDBS (90.5%) and COD (70.7%) reduction efficiency was obtained at the optimal conditions of 60 min, pH 4 and 8.82 mM of H2O2 and 3.67mM of Fe +3. In this work, the effects of some organic compounds on the degradation of SDBS by Fenton-like process were examined. The results showed that 50 mgL-1 of oxalic acid slightly enhanced the SDBS degradation efficiency while acetic acid and Ethylenediaminetetraacetic acid (EDTA) reduced it.

Research paper thumbnail of Electro-activated persulfate oxidation (EC/PS) for the treatment of real oilfield produced water: Optimization, developed numerical kinetic model, and comparison with thermal/EC/PS and EC systems

Process Safety and Environmental Protection, 2021

Abstract In this study, the performance and efficiency of electrocoagulation (EC), electro-activa... more Abstract In this study, the performance and efficiency of electrocoagulation (EC), electro-activation of persulfate (EC/PS), and thermal activated-EC/PS for the treatment of two real produced water (PW) samples using iron electrodes were studied. To optimize and find out the effect of operating conditions on the different responses for EC and EC/PS, response surface methodology (RSM) was implemented. The results showed that EC process had considerable performance in the removal of H2S (96 %), oil and grease (O&G) (98–99 %), turbidity (91–97 %), phosphate phosphors (94 %), and heavy metals (92 %). EC/PS was introduced as an effective and a compact method for the removal of soluble hydrocarbons and nitrogen-ammonium (N-NH4+). The results indicated that at the current density of 35 A/m2, PS of 30 mM, reaction time of 30 min, N-NH4+ and chemical oxygen demand (COD) removal efficiency increased to 37 % and 71–94 %, respectively. To further increase the ammonia removal, EC/PS was integrated into thermal-PS activation at 65 °C, and the results showed that the ammonia removal by thermal/EC/PS reached about 69 %. According to gas chromatography/mass spectrometry (GC/MS), EC/PS was able to effectively eliminate most of the hydrocarbons. Moreover, a new kinetic model based on a novel algorithm and the main reactions occurring during EC/PS was developed to predict the COD removal efficiency, and the results indicated that it could predict COD removal efficiency with the acceptable accuracy. The estimated operating costs and energy consumption for EC/PS demonstrated that this process was more economical and efficient than other advanced oxidation processes (AOPs).

Research paper thumbnail of Advanced oxidation process as a green technology for dyes removal from wastewater: A review

Iranian Journal of Chemistry & Chemical Engineering-international English Edition, 2020

The combination of green chemistry and green engineering is needed for the production of minimum ... more The combination of green chemistry and green engineering is needed for the production of minimum waste, renewable sources, an increasing utilization of raw materials, use of simpler and safer products, and novel technologies. The use of novel cleaner technologies lead to effective productions in chemical industries. The dyes involve the complex structure, recalcitrant nature, and more intermediates. The generation of oxidative species with higher yields is obtained by advanced oxidation processes as a green and powerful treatment technology. These processes are the effective, inexpensive and eco-friendly methods for decaying the toxic pollutants. The AOPs are classified as non-photochemical and photochemical processes. There are included various technologies such as ozonation, Fenton oxidation, wet air oxidation, electrochemical oxidation and photocatalytic oxidation. The production of highly reactive free radicals is the main purpose of the AOPs process. The generation of free radi...

Research paper thumbnail of Removing Iron, Manganese and Ammonium Ions from Water Using Greensand in Fluidized Bed Process

Journal of Water Process Engineering, 2021

Natural minerals are used as sorbent in water treatment processes due to their high exchange and ... more Natural minerals are used as sorbent in water treatment processes due to their high exchange and relatively low cost. In this paper, a pilot water treatment was conducted to explore the application of greensand in a fluidized bed column while the iron, manganese and ammonium removal performances of two treatment processes, including greensand filtration and potassium permanganate-greensand filtration were evaluated. The breakthrough curves were investigated to analyze the effect of variables such as bed height and inlet flow on the removal performance in addition to the physical properties of greensand. The results showed that the effect of potassium permanganate on the outlet concentration of the fluidized bed was significant in terms of the breakthrough curves which led to the breakthrough points for iron and manganese. It was found that adding potassium permanganate increased the equilibrium column capacity (q eq) from 5.18 mg/g and 2.16 mg/g to 12.70 mg/g and 11.29 mg/g for iron and manganese respectively. So Fe and Mn outlet concentrations reached under the admissible maximum concentration of drinking water. In the experiments without KMnO 4 , iron removal was found to be caused by reductive dissolution and adsorption while adsorption was the only mechanism for manganese removal. The findings indicated that ammonium removal was minimally influenced by KMnO 4 and ion exchange was the main mechanism for ammonium removal.

Research paper thumbnail of Estimation of effluent parameters of slaughterhouse wastewater treatment with artificial neural network and B-spline quasi interpolation

International Journal of Environmental Research, 2020

Effluent of slaughterhouse wastewater treatment by combined up-flow anaerobic sludge blanket (UAS... more Effluent of slaughterhouse wastewater treatment by combined up-flow anaerobic sludge blanket (UASB) reactor and extended aeration reactor was estimated through artificial neural networks (ANN), ANN-genetic algorithm (GA) and B-spline quasi interpolation. The overall system operated at two runs with average total chemical oxygen demand (TCOD) of 1514.65 and 3160.2 mg/L for the first and second run, respectively; with two overall hydraulic retention times of 73 and 104 h for each run. The overall system could remove TCOD, ammonia, phosphate and turbidity to a high extent. The multilayer perceptron artificial neural network (MLPANN) trained by Levenberge-Marquardt algorithm was employed to predict the TCOD, ammonia, phosphate and turbidity of the effluent which resulted in R of 0.8257, 0.6274, 0.7961 and 0.6884, respectively. The optimization of MLPANN by GA performed better than MLPANN with R of 0.8390, 0.7650, 0.8107 and 0.7365 for TCOD, ammonia, phosphate and turbidity, respectively. The B-spline quasi interpolation indicates a more accurate prediction due to its R of 0.9619, 0.8806, 0.8307 and 0.7856 for TCOD, ammonia, phosphate and turbidity, respectively. The B-spline quasi interpolation operation time is notably lower than ANN and ANN-GA. In addition, it has a simple algorithm and is implemented easier than the artificial neural network model. Article Highlights • Slaughterhouse wastewater treatment by combined biological process. • Multi-layer perceptron, genetic algorithm and B-spline quasi interpolation were used for prediction. • Prediction of total COD, ammonia, phosphate and turbidity. • Effect of HRT investigated on removal efficiency.

Research paper thumbnail of Treatment of wood industry wastewater by combined coagulation–flocculation–decantation and fenton process

Water Environment Research, 2020

In the present research, the efficiency of turbidity and chemical oxygen demand (COD) reduction f... more In the present research, the efficiency of turbidity and chemical oxygen demand (COD) reduction from the wood industry wastewater (WIW) by the use of a combined coagulation-flocculationdecantation (CFD)-Fenton process was studied. Firstly, the performance of three coagulants such as ferric chloride (FeCl 3), aluminum sulfate (alum), and poly-aluminum chloride (PACl) was evaluated. The polyacrylamide (PAM) was used as a flocculant. The results showed that the polyaluminum chloride had a high removal efficiency. The COD reduction of 84.1% and turbidity removal of 82.0% of were obtained in coagulation-flocculation-decantation (CFD). Secondly, Fenton process was optimized, by the use of a response surface methodology (RSM), with application of a central composite design (CCD). The maximum turbidity and COD removal obtained by this process were 94.1 and 72.5% respectively, under optimal conditions ([Fe 2+ ] = 250 mg/L, [H 2 O 2 ] = 500 mg/L, pH 3.5, time 60 min). The kinetics of COD and turbidity removal were determined by the model of first order. In conclusion, the combination of coagulation-flocculation-Accepted Article This article is protected by copyright. All rights reserved decantation (CFD)-Fenton process presented as a remarkable method for wood wastewater treatment.

Research paper thumbnail of Saline oily wastewater treatment using Lallemantia mucilage as a natural coagulant: Kinetic study, process optimization, and modeling

Industrial Crops and Products, 2021

Abstract Saline oily wastewater is among the greatest environmental issues that requires effectiv... more Abstract Saline oily wastewater is among the greatest environmental issues that requires effective treatment methods. The new trend of using natural coagulants to treat saline oily wastewater can help overcome the drawbacks of inorganic coagulants such as high costs, health risk, and large amounts of sludge. In the present study, the Lallemantia mucilage was used for the first time as a novel natural coagulant, which offered a remarkable performance in bilge water treatment at the optimum condition of coagulants dose = 10 mg/L, pH = 7.00, and contact time = 23.8 min with the maximum chemical oxygen demand (COD) removal efficiency of 87.57 % and influent COD of 1202.5 ± 8.5 mg/L. Also, at the optimum condition, Lallemantia mucilage could remove surfactant up to 20.6 % with influent concentration of 55 ± 0.4 mg/L. A quadratic polynomial with R2 = 0.9943 for COD removal showed a satisfactory fit and consistency. The predictability of Multivariate Adaptive Regression Splines (MARS) method with R 2 = 0.95235 was significant compared to the Response Surface Methodology (RSM) with R 2 = 0.9599. The second-order kinetic equation performed better in terms of kinetic determination with k = 0.00009, E = 1.42776E+13, and R 2 = 0.9642 than the first-order model with k = 0.0159, E = 2.52237E+15, and R 2 = 0.9431.

Research paper thumbnail of Removal of TCOD and phosphate from slaughterhouse wastewater using Fenton as a post-treatment of an UASB reactor

Journal of Environmental Health Science and Engineering, 2020

A pilot was designed to study the removal efficiencies of total chemical oxygen demand (TCOD) and... more A pilot was designed to study the removal efficiencies of total chemical oxygen demand (TCOD) and phosphate by a combined biological and chemical method. Two stages of Up-flow anaerobic sludge blanket (UASB) reactor and advanced oxidation processes was operated in batch mode. The UASB reactor was operated with hydraulic retention time of 26 h. UASB removal efficiency of TCOD and phosphate were 62.2 and 36.5%, respectively. Fenton process was used as a post-treatment so as to remove organic matter and nutrients. At this stage, the removal efficiencies of TCOD and phosphate were investigated considering the effect of parameters such as pH, hydrogen peroxide and Fe (II) dose based on Taguchi experimental design. Accordingly, under optimum conditions, pH = 3, 1000 mg/l of H 2 O 2 and 400 mg/l of Fe (II) the removal efficiencies of TCOD and phosphate reached 95.41 and 85.29%, respectively. The combined method removed TCOD and phosphate up to 98.6 and 90.5%, respectively.

Research paper thumbnail of Sulphate radical-based advanced oxidation technologies for removal of COD and ammonia from hazardous landfill leachate: A review

International Journal of Environmental Analytical Chemistry, 2021

Research paper thumbnail of Advanced numerical kinetic model for predicting COD removal and optimisation of pulp and paper wastewater treatment by Fenton process

International Journal of Environmental Analytical Chemistry, 2020

In the present study, a kinetic model has been developed to predict the chemical oxygen demand (C... more In the present study, a kinetic model has been developed to predict the chemical oxygen demand (COD) removal efficiency of Fenton process for the treatment of pulp and paper mill (P&P) wastewater. In order to investigate the effects of main parameters including Fe (II) dosage, H 2 O 2 dosage, and pH, 45 experiments have been carried out at three levels for each parameter, and thus COD removal efficiency has been obtained. The Fenton process was simulated by using 10main reactions, and the model was solved numerically according to a specific algorithm. All the pollutants in the P&P wastewater were assumed to be a pseudo-material, andapparent kinetic constant (k**)was calculated using a developed iterative method. The results of the numerical model indicated that the proposed model had a great potential to predict COD removal efficiency for P&P wastewater by Fenton in comparison to the first and second-order kinetic models. Accordingly, R-squared (R 2), Root Mean Square Error (RMSE), and Mean Relative Error (MRE) of the numerical kinetic model were 0.93, 4.296 × 10 −7 , and 0.035, respectively, implying remarkable accuracy of the numerical model. Furthermore, at the optimum point of Fenton process,which was pH: 3,[H 2 O 2 ]:0.015 Molar, and [Fe(II)]: 0.015 Molar, the COD removal efficiency of P&P wastewater reached 78%. As the basis of the numerical model was established according to mechanisms of Fenton process, the results demonstrated the great performance of the advanced kinetic model in the estimation of the COD removal efficiency, the behaviour of effective parameters such as pH, H 2 O 2 , and Fe(II) along with their effects on k**, and Fe(III) accumulation during Fenton process.

Research paper thumbnail of Evaluation of COD removal by biologically GSBR from photocatalytically pre-treated oilfield produced water

DESALINATION AND WATER TREATMENT, 2020

Today combined photo-assisted advanced oxidation process (AOP) and biological processes are gaini... more Today combined photo-assisted advanced oxidation process (AOP) and biological processes are gaining in importance as treatment systems. The use of AOPs as a pretreatment step to enhance the biodegradability of produced water (PW) can be justified if the resulting intermediates are readily degradable by microorganisms in further biological treatment. Therefore, investigating the relationshipbetweenadvancedoxidationpretreatedeffluentandsubsequentbioreactorperformance can help to optimize these systems. In this study, an integrated solar photoreactor-granular bioreactorwasusedtotreatsyntheticandrealproducedwater.Solarphotoreactorwasdesignedand optimized using a cascade falling film theory and TiO 2 /SnO 2 /CuO photocatalyst supported on the Scoria-concrete surface. The effects of various operational parameters on the photocatalytic process wereinvestigatedusingresponsesurfacemethodology(RSM).Optimumbiochemicaloxygendemand (BOD 5)/chemical oxygen demand (COD) ratio of 0.40 was achieved at pH of 6.5, a photocatalyst concentrationof60gL-1 ,temperatureof40°C,lightexposuretimeof70minandH 2 O 2 concentration of2.5mM.PhotoreactoreffluentwithCODandBODof1,042±10and432±4wasfedintotheaerobic granularbioreactor,respectively.TheremovedCODbythebiologicaltreatmentwas50%,whereasby thecombinedphotocatalytic-biologicaltreatmentitwasreachedto94%.Inthecaseofrealproduced water,theremovalefficiencywasdecreasedto92%.Granulestructurewasdeterminedusingscanning electron microscopy. The combined biological-photocatalytic treatment significantly shortened the degradation and mineralization time of the biological treatment.

Research paper thumbnail of Effects of Various Plants on Treatment Efficiency of Horizontal Subsurface Flow Constructed Wetlands Based on the Hydraulic Retention Time

Environmental Engineering and Management Journal, 2019

In this study the effectiveness of Lactuca sativa, Medicago sativa and Phragmites australis for t... more In this study the effectiveness of Lactuca sativa, Medicago sativa and Phragmites australis for the treatment of domestic wastewater in horizontal subsurface flow was investigated. The removal efficiency of chemical oxygen demand (COD), total nitrogen (TKN), total phosphorus (TP), and total suspended solids (TSS) was measured. The experiment was conducted in two different retention time (5 and 7 days) in three seasons (spring, summer and fall). The removal efficiency was increased as the retention time increased. Based on the results, M. sativa had the highest removal efficiency of COD (90.7%), TSS (87.8%) and TKN (59%) in 7 days HRT. Meanwhile, P. australis removed (67%) TP during 7 days HRT from wastewater. Seasonal changes showed different effects on removal rate and L. sativa showed lower removal efficiency in compare to other two plants.

Research paper thumbnail of Biological treatment of slaughterhouse wastewater: kinetic modeling and prediction of effluent

Journal of Environmental Health Science and Engineering, 2019

In this study three modeling approaches consisting Modified Stover-Kincannon, multilayer perceptr... more In this study three modeling approaches consisting Modified Stover-Kincannon, multilayer perceptron neural network (MLPANN) and B-Spline quasi interpolation were applied in order to predict effluent of up-flow anaerobic sludge blanket (UASB) reactor and also to find the reaction kinetics. At first run, the average total chemical oxygen demand (TCOD) removal efficiency was 48.3% with hydraulic retention time (HRT) of 26 h and 63.8% with HRT of 37 h, at OLR of 0.77-1.66 kg TCOD/m 3 d. At the second run, UASB reactor operated with OLR of 1.94-3.1 kg TCOD/m 3 d and achieved the average TCOD removal efficiency of 64.74 and 72.48% with HRT of 26 and 37 h, respectively. The Modified Stover-Kincannon performed well in terms of kinetic determination with a high value of regression coefficient over 0.98. The B-Spline quasi interpolation and MLPANN indicated a great fit for effluent prediction with average R of 0.9984 and 0.9986, and MSE of 157.6050 and 129.7796, respectively; however, they gave no information about reactions occurred in the system. Keywords Biological treatment. TCOD removal. Modified Stover-Kincannon. Artificial neural network. B-spline quasi interpolation Highlights • Performance of up-flow anaerobic sludge blanket reactor. • Effect of HRT on removal efficiency. • Multi-layer perceptron and B-Spline quasi interpolation were used in order to predict the effluent of UASB reactor. • Kinetic modeling of UASB reactor by modified Stover-Kincannon.

Research paper thumbnail of Evaluation of COD and turbidity removal from woodchips wastewater using biologically sequenced batch reactor

Process Safety and Environmental Protection, 2019

Highlights  The SBR process is introduced as an efficient method for woodchips wastewater treatm... more Highlights  The SBR process is introduced as an efficient method for woodchips wastewater treatment•  The high efficiency of SBR indicates that woodchips can act as an auxiliary carbon source for microbial respiration in this process•  The best performance of this process is that the COD concentration will be obtained according to the standard limit of Iran (<100) without using chemical processes• ABSTRACT: The wood industry consumes a lot of water. Due to the reduction of water resources in the world, the treatment of this contaminated water is very essential. In this study, the removal efficiencies of the chemical oxygen demand (COD) and turbidity from woodchips wastewater with the use of a sequencing batch reactor (SBR) were studied at a bench scale. Woodchips wastewater samples were collected with a COD of 1300 mg L-1 and a turbidity of 93 NTU. The optimization of the SBR process was investigated by response surface methodology (RSM) based on a central composite design (CCD). A quadratic polynomial model was fit to the data with R 2 of 0.9919 for COD reduction, R 2 of 0.9910 for turbidity removal, and R 2 of 0.9945 for sludge volume Index (SVI), respectively. The effect of three parameters, including initial COD, mixed liquor suspended solids (MLSS), and Hydraulic retention time (HRT) on the COD reduction and turbidity removal were evaluated. The initial COD (A), MLSS (B), cycle time (C), AB, AC, BC, A 2 , B 2 , and C 2 were considered as the affective parameters in the COD reduction. Initial COD (A), MLSS (B), A 2 , B 2 , C 2 , AC, and BC were observed as the remarkable model terms on the turbidity removal. Also, initial COD (A), MLSS (B), cycle time (C), B 2 , C 2 , and BC were the significant model factors in SVI index. At optimal conditions, involving an initial COD of 1000 mg L-1 , an organic loading rate (OLR) of 0.450 kg COD/m 3 d, MLSS of 3000 mg L-1 , and cycle time of 24 h, we observed 94.6% of COD reduction, 98.5% turbidity removal, and 79 mL g-1 SVI. The results also showed that the kinetic of COD reduction and turbidity removal could be represented by the pseudo-second-order model.

Research paper thumbnail of Treatment of pulp and paper wastewater by lab-scale coagulation/SR-AOPs/ultrafiltration process: optimization by Taguchi

DESALINATION AND WATER TREATMENT, 2017

In this study, the treatment of pulp and paper wastewater using combined approach of coagulation/... more In this study, the treatment of pulp and paper wastewater using combined approach of coagulation/ sulfate radical-advanced oxidation process (SR-AOPs)/ultrafiltration (UF) was studied in the lab scale. In the beginning of this system, the performance of three coagulants such as polyaluminum chloride (PACl), ferric chloride (FeCl 3) and alum was evaluated to achieve high recycled fiber. According to the results yielded, the FeCl 3 , with high fiber recycling (98%) and removal efficiency, was more efficacious. In the next step, the potassium persulfate (PPS)-Fe(II) and PPS-Fe(III) efficiency in the removal of the chemical oxygen demand (COD), aromatic compounds (UV 254) and the value of sludge volume index were evaluated using Taguchi design of the experiment. The results showed that the removal efficiency of COD and UV 254 in the process of PPS-Fe(II) was 92.6% and 95.8% which had the better performance than the process of PPS-Fe(III). The results showed that electrical conductivity (EC) in coagulation/SR-AOPs had increased to 30.64%. Moreover, there was a significant amount of sulfate in the effluent; whereas, UF was applied. Accordingly, using UF after pretreatment by coagulation/PPS-Fe(II), the removal efficiency of sulfate, EC, COD and UV 254 increased to 99.44%, 62.05%, 97.35% and 98.75%, respectively.

Research paper thumbnail of Combined Fenton-like oxidation and aerobic MBBR biological processes for treatment of the wastewater of detergent industries

DESALINATION AND WATER TREATMENT, 2017

Surfactant is one of the most important compounds widely used in the formulation and structure of... more Surfactant is one of the most important compounds widely used in the formulation and structure of detergents all over the world. In this study, we investigated the combined Fenton-like oxidation and aerobic moving bed biofilm reactor (MBBR) biological processes for treatment of the wastewater of detergent industries. The average chemical oxygen demand (COD) and linear alkylbenzene sulfonate (LAS) in the raw wastewater were 24,039 and 210 mg/L, respectively. The maximum removal efficiencies of the pretreatment and Fenton-like oxidation process for COD and LAS were 95% and 90%, respectively, and the effluent concentrations of COD and LAS were about 1,250 and 100 mg/L, respectively. For MBBR process, in reactor 1 (with lower LAS concentrations) with 36 h hydraulic retention time (HRT), the maximum removal efficiencies were found to be 94.20% and 99.99% for the influent COD and LAS, respectively (R 2 = 0.93 and p < 0.05 and R 2 = 0.92 and p < 0.05). Also, for reactor 2 (with higher LAS concentrations), in the same condition with 36 h HRT, the maximum removal efficiencies were 93.41% and 95% for the influent COD and LAS, respectively (R 2 = 0.92 and p < 0.05 and R 2 = 0.84 and p < 0.05). This investigation shows that Fenton-like oxidation process, in combination with MBBR process, can provide the local effluent discharge standard for detergent industries.

Research paper thumbnail of Integrated systems for oilfield produced water treatment: The state of the art

Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2016

ABSTRACT Produced water (PW) is considered as one of the largest waste streams in the petroleum, ... more ABSTRACT Produced water (PW) is considered as one of the largest waste streams in the petroleum, oil, and gas industry. The drilling and extraction operations aiming to maximize the production of oil may be counterbalanced by the huge production of contaminated water with pollutants, such as heavy metals and organic compounds. This review provides insight into the implementation of different technologies in the petroleum industry for treating PW generated from conventional oilfields in upstream and downstream processes. Scientific efforts in the future can concentrate on developing the most economical and environmentally compliant solutions for the management of untreated PW.