George Nakhla - Academia.edu (original) (raw)

Papers by George Nakhla

Research paper thumbnail of Pretreatment of Primary Sludge Prior to Anaerobic Digestion

Research paper thumbnail of Pretreatment of Hog Manure Prior to Anaerobic Digestion

Research paper thumbnail of Landfill Leachate Biological Treatment Using a Pilot Liquid-Solid Circulating Fluidized Bed Bioreactor (LSCFB)

Research paper thumbnail of A Novel Liquid Based Epoxy-Functionalized Zeolite Coating for Protection of Concrete Pipes from Biogenic Corrosion

Proceedings of the Water Environment Federation, 2008

ABSTRACT

Research paper thumbnail of Hydrogen Production From Oleic Acid and Starch Over Supported Metal Catalysts in Supercritical Water

Research paper thumbnail of 339780 Advanced Oxidation of Estrone in Water and Wastewater

Natural estrogen, estrone (E1) is one of the most potent endocrine disrupting compounds (EDC) whi... more Natural estrogen, estrone (E1) is one of the most potent endocrine disrupting compounds (EDC) which is of primary concern due to its widespread presence in the aqueous environment and also due to its adverse impact both on aquatic life and potential risk to human health. Conventional waste water treatment plants are not designed to remove it, and most of it remains adsorbed on the activated sludge, while part of it is being discharged with secondary effluent, requiring tertiary treatment for water recycle, surface water protection, as well as surface water augmentation. Advanced oxidation processes (AOPs) are seen as promising technologies for removal of estrogens from environment. In this work, a comprehensive research was conducted to determine the relative performance of various advanced oxidation processes such as O3, H2O2, UV, and combinations of UV/ O3, UV/H2O2,ultrasonication, and Fenton agent for the removal of E1 from pure water and secondary effluent. In addition to the pa...

Research paper thumbnail of Liquid-Solid Circulating Fluidized Bed Bioreactor in Wastewtaer Treatment

A pilot scale liquid-solid circulating fluidized bed bioreactor was established at the Adelaide P... more A pilot scale liquid-solid circulating fluidized bed bioreactor was established at the Adelaide Pollution Control Plant, London, Canada, to study the feasibility of this novel technology for municipal wastewater treatment using 600 μm lava rock particles as a carrier media, with emphasis on biological nutrient removal. The LSCFB generated effluent characterized by this system was characterized by <1.0 mg NH 4 -N/L, <5.0 mg NO 3 -N/L, <1.0 mg PO 4 -P/L, <10 mg TN/L, <10 mg SBOD/L, and 10-15 mg VSS/L, which can meet secondary effluent quality without using any chemical for phosphorus removal and conventional secondary clarification for removing suspended solids. This system can easily regenerate MWW at an organic, nitrogen, and phosphorus loading rates of 4.12 kg COD/(m 3 ·d), 0.35 kg N/(m 3 ·d), and 0.051 kg P/(m 3 ·d) respectively. The observed yields were 0.12-0.16 g VSS/g COD consumed in the LSCFBs during nutrient removal from MWW. Ultraviolet disinfection test show...

Research paper thumbnail of Sono-Thermal Pretreatment of Waste Activated Sludge for Enhanced Anaerobic Digestion and Volatile Sulfur Compounds Control in Biogas

Proceedings of the Water Environment Federation, 2011

Abstract: The impact of sono-thermal pretreatment combining ultrasound and conventional heating a... more Abstract: The impact of sono-thermal pretreatment combining ultrasound and conventional heating as a pretreatment process for municipal waste activated sludge prior to anaerobic digestion is evaluated in terms of sludge solubilization, solids reduction, biogas production, volatile sulfur compounds concentrations in biogas, dewaterability of digested sludge, and economic feasibility of the pretreatment process. A total of nine combined sono-thermal pretreatments were conducted using three different ultrasound specific energy inputs ( ...

Research paper thumbnail of Calibration Protocol for the Particulate Biofilm Models Used in Biological Wastewater Treatment

Proceedings of the Water Environment Federation, 2012

ABSTRACT In order to enhance the use of biofilm models for simulation of wastewater treatment pla... more ABSTRACT In order to enhance the use of biofilm models for simulation of wastewater treatment plants (WWTPs), model calibration is absolutely necessary. The aim of this work was to develop a calibration protocol for biofilm processes model with a help of the sensitivity analysis of the most important parameters implemented in BioWin® software. A case study of a circulating fluidized bed bioreactor (CFBBR) system used for biological nutrient removal (BNR) from municipal wastewater was used to verify and validate the proposed calibration protocol. Applying the various stages of the proposed biofilm calibration procedures enhanced the applicability of BioWin®, which was capable of predicting most of the performance parameters with an average percentage error (APE) of 0% to 20%. Although the calibrated model predicted most of the performance parameters, BioWin® predicted the total biomass and SRT based on active biomass only, whereas in the CFBBR both active as well as inactive biomass accumulated.

Research paper thumbnail of Influence of biofilm thickness on nitrous oxide (N2O) emissions from denitrifying fluidized bed bioreactors (DFBBRs)

Journal of Biotechnology, 2014

Research paper thumbnail of Mitigation of nitrous oxide (N2O) emissions from denitrifying fluidized bed bioreactors (DFBBRs) using calcium

Bioresource Technology, 2014

Research paper thumbnail of Liquid-solid circulating fluidized bed waste water treatment system for simultaneous carbon, nitrogen and phosphorus removal

Research paper thumbnail of Anaerobic digestion of municipal wastewater sludges using anaerobic fluidized bed bioreactor

Bioresource Technology, 2014

The anaerobic digestion of primary sludge (PS) and thickened waste activated sludge (TWAS) using ... more The anaerobic digestion of primary sludge (PS) and thickened waste activated sludge (TWAS) using an anaerobic fluidized bed bioreactor (AnFBR) employing zeolite particles as the carrier media was investigated at different organic loading rates (OLRs). PS was tested at OLRs from 4.2 to 39kgCOD/m(3)-d corresponding to hydraulic retention times (HRTs) from 1.0 to 8.9days. The highest COD removal and VSS destruction efficiencies for primary sludge of 85% and 88%, respectively, were achieved at an HRT of 8.9days and OLR of 4.2kgCOD/m(3)-d. For TWAS, VSS destruction efficiencies varied from 42% at an HRT of 2.6days and OLR of 13.1kgCOD/m(3)-d to 69% at an HRT of 8.8days and an OLR of 4.2kgCOD/m(3)-d. The first-order COD biodegradation rates in the AnFBR for PS and TWAS were 0.4d(-1) and 0.1d(-1), respectively, almost double the rates in conventional high-rate digesters.

Research paper thumbnail of Circulating Fluidized Bed Bioreactor: A Cost-effective Technology for Wastewater Treatment

Proceedings of the Water Environment Federation, 2012

ABSTRACT This study was focused on evaluating the economic feasibility of a newly developed techn... more ABSTRACT This study was focused on evaluating the economic feasibility of a newly developed technology, the Circulating Fluidized Bed-Bioreactor [CFBBR] compared to alternative technologies e.g. activated sludge process [AS], moving bed bioreactor [MBBR], and sequencing batch reactor [SBR] for municipal wastewater treatment. The CFBBR combines a circulating fluidized bed and a fixed-film process for an enhanced solid-liquid mass transfer that provides higher removal rates of nitrogen and phosphorous compared to the AS, MBBR, and SBR processes. Both labscale and pilot-scale CFBBRs demonstrated &gt; 90% COD, &gt; 80% N and 70% P removal at a hydraulic retention time of 2 h without primary clarification. Furthermore, the observed sludge yields of 0.12-0.16 g VSS/g COD consumed in the CFBBR resulted in 75% reduction in total biosolids production compared to conventional activated sludge non BNR treatment processes. The CFBBR demonstrated the potential for significant capital cost reduction, compliance with stringent regulations, reduction of biosolids, and up to 80% reduction in space requirements. Cost modules have been developed using CapDet Works 2.5 for the different processes employing reactor sizes designed for an average daily flow of 2.6 MGD (10,000 m3/d). The cost modules consist of screening, grit chamber, primary clarifier, biological nutrient removal units, secondary clarifier, UV-disinfection, thickening, anaerobic digestion, energy recovery, dewatering and sludge handling and disposal. The CFBBR was determined to be the most cost effective technology compared to the conventional BNR-AS and other available technologies for a completely new wastewater treatment facility. Even though the CFBBR does require high recirculation volume (12 times influent flow) to fluidize particles, energy consumption of 0.33 kWh/m3 in the CFBBR is less than the energy required in the MBBR (0.39kWh/m3), SBR (0.41 kWh/m3), and in the same range of the BNR-AS (0.31 kWh/m3) for biological nutrient removal from municipal wastewater.

Research paper thumbnail of Impact of alkaline-hydrolyzed biosolids (Lystek) addition on the anaerobic digestibility of TWAS in lab--and full-scale anaerobic digesters

Waste management (New York, N.Y.), 2014

The effect of different Lystek biosolids doses on the anaerobic digestability of thickened waste ... more The effect of different Lystek biosolids doses on the anaerobic digestability of thickened waste activated sludge (TWAS) was evaluated in a lab- and full-scale anaerobic digester. The overall findings of this study emphasize the beneficial impact of Lystek addition to the lab- and full-scale anaerobic digesters in terms of enhanced biogas production and increased volatile suspended solids reduction (VSSR) efficiency. Lystek added at 4% by volume to TWAS increased the methane yield from 0.22 to 0.26 L CH4/g VSSadded at an solids retention time (SRT) of 10 days, and from 0.27 to 0.29 L CH4/g VSS(added) at an SRT of 15 days. Furthermore, the VSSRs of 37% and 47% were observed for the TWAS, and the TWAS with 4% Lystek, while at an SRT of 15 days, the observed VSSR were 49% and 58%, respectively. The lab-scale study showed that the influence of Lystek addition on methane yield and solids destruction efficiencies was more pronounced at the shorter SRT, 20% enhancement (SRT of 10d) vs. 9% ...

Research paper thumbnail of Anaerobic digestibility of estrogens in wastewater sludge: Effect of ultrasonic pretreatment

Journal of Environmental Management, 2014

Research paper thumbnail of Degradation of estrone in water and wastewater by various advanced oxidation processes

Journal of Hazardous Materials, 2014

Research paper thumbnail of Comparison of Biofoulants in BNR-MBR and Conventional MBR (C-MBR) Systems

Proceedings of the Water Environment Federation, 2008

ABSTRACT

Research paper thumbnail of Treatment of Food Industry Waste by Bench-Scale Upflow Anaerobic Sludge Blanket-Anoxic-Aerobic System

Water Environment Research, 2006

An upflow anaerobic sludge blanket (UASB)-anoxicaerobic system was used for treatment of tomato a... more An upflow anaerobic sludge blanket (UASB)-anoxicaerobic system was used for treatment of tomato and bean processing wastewater. At various hydraulic retention times, ranging from 0.7 to 5 days, excellent removal of chemical oxygen demand (COD), biochemical oxygen demand (BOD), total suspended solids (TSS), ammonia-nitrogen (NH4-N), and total Kjeldahl nitrogen was achieved with final effluent BOD/TSS/NH4N concentrations of less than 15/15/1 mg/L. Biogas yield in the UASB reactor varied from 0.33 to 0.44 m3/kgCODremoved. The kinetics of anaerobic treatment were investigated. The yield coefficient was 0.03 gVSS/gCOD; maximum specific growth rate was 0.24 day(-1); Monod half velocity constant was 135 mgCOD/L; and specific substrate utilization rate was 3.25 gCOD/gVSS x d. Nitrification and denitrification kinetics were studied in batch experiments, and the rates were comparable with those in the continuous flow system.

Research paper thumbnail of Pilot-scale Experience with Biological Nutrient Removal and Biomass Yield Reduction in a Liquid-solid Circulating Fluidized Bed Bioreactor

Water Environment Research, 2010

A pilot-scale liquid-solid circulating fluidized bed (LSCFB) bioreactor was developed at the Adel... more A pilot-scale liquid-solid circulating fluidized bed (LSCFB) bioreactor was developed at the Adelaide Pollution Control Plant, London, Ontario, Canada, to study its commercial viability for biological nutrient removal. Lava rock particles of 600 microm were used as a biomass carrier media. The LSCFB removed approximately 90% organic, 80% nitrogen, and 70% phosphorus at loading rates of 4.12 kg COD/m3 x d, 0.26 kg N/m3 x d, and 0.052 kg P/m3 x d, and an empty bed contact time of 1.5 hours. Effluent characterized by &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 1.0 mg NH4-N/L, &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 5.0 mg NO3-N/ L, &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 1.0 mg PO4-P/L, &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 10 mg TN/L, &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 10 mg SBOD/L, and 10 to 15 mg volatile suspended solids (VSS)/L can easily meet the criteria for nonpotable reuse of treated wastewater. The system removed nutrients without using any chemicals, and the secondary clarifier removed suspended solids removal without chemicals. A significant reduction (approximately 75%) in biomass yield to 0.12 to 0.16 g VSS/g chemical oxygen demand (COD) was observed, primarily because of long biological solids retention time (SRT) of 20 to 39 days and a combination of anoxic and aerobic COD consumption.

Research paper thumbnail of Pretreatment of Primary Sludge Prior to Anaerobic Digestion

Research paper thumbnail of Pretreatment of Hog Manure Prior to Anaerobic Digestion

Research paper thumbnail of Landfill Leachate Biological Treatment Using a Pilot Liquid-Solid Circulating Fluidized Bed Bioreactor (LSCFB)

Research paper thumbnail of A Novel Liquid Based Epoxy-Functionalized Zeolite Coating for Protection of Concrete Pipes from Biogenic Corrosion

Proceedings of the Water Environment Federation, 2008

ABSTRACT

Research paper thumbnail of Hydrogen Production From Oleic Acid and Starch Over Supported Metal Catalysts in Supercritical Water

Research paper thumbnail of 339780 Advanced Oxidation of Estrone in Water and Wastewater

Natural estrogen, estrone (E1) is one of the most potent endocrine disrupting compounds (EDC) whi... more Natural estrogen, estrone (E1) is one of the most potent endocrine disrupting compounds (EDC) which is of primary concern due to its widespread presence in the aqueous environment and also due to its adverse impact both on aquatic life and potential risk to human health. Conventional waste water treatment plants are not designed to remove it, and most of it remains adsorbed on the activated sludge, while part of it is being discharged with secondary effluent, requiring tertiary treatment for water recycle, surface water protection, as well as surface water augmentation. Advanced oxidation processes (AOPs) are seen as promising technologies for removal of estrogens from environment. In this work, a comprehensive research was conducted to determine the relative performance of various advanced oxidation processes such as O3, H2O2, UV, and combinations of UV/ O3, UV/H2O2,ultrasonication, and Fenton agent for the removal of E1 from pure water and secondary effluent. In addition to the pa...

Research paper thumbnail of Liquid-Solid Circulating Fluidized Bed Bioreactor in Wastewtaer Treatment

A pilot scale liquid-solid circulating fluidized bed bioreactor was established at the Adelaide P... more A pilot scale liquid-solid circulating fluidized bed bioreactor was established at the Adelaide Pollution Control Plant, London, Canada, to study the feasibility of this novel technology for municipal wastewater treatment using 600 μm lava rock particles as a carrier media, with emphasis on biological nutrient removal. The LSCFB generated effluent characterized by this system was characterized by <1.0 mg NH 4 -N/L, <5.0 mg NO 3 -N/L, <1.0 mg PO 4 -P/L, <10 mg TN/L, <10 mg SBOD/L, and 10-15 mg VSS/L, which can meet secondary effluent quality without using any chemical for phosphorus removal and conventional secondary clarification for removing suspended solids. This system can easily regenerate MWW at an organic, nitrogen, and phosphorus loading rates of 4.12 kg COD/(m 3 ·d), 0.35 kg N/(m 3 ·d), and 0.051 kg P/(m 3 ·d) respectively. The observed yields were 0.12-0.16 g VSS/g COD consumed in the LSCFBs during nutrient removal from MWW. Ultraviolet disinfection test show...

Research paper thumbnail of Sono-Thermal Pretreatment of Waste Activated Sludge for Enhanced Anaerobic Digestion and Volatile Sulfur Compounds Control in Biogas

Proceedings of the Water Environment Federation, 2011

Abstract: The impact of sono-thermal pretreatment combining ultrasound and conventional heating a... more Abstract: The impact of sono-thermal pretreatment combining ultrasound and conventional heating as a pretreatment process for municipal waste activated sludge prior to anaerobic digestion is evaluated in terms of sludge solubilization, solids reduction, biogas production, volatile sulfur compounds concentrations in biogas, dewaterability of digested sludge, and economic feasibility of the pretreatment process. A total of nine combined sono-thermal pretreatments were conducted using three different ultrasound specific energy inputs ( ...

Research paper thumbnail of Calibration Protocol for the Particulate Biofilm Models Used in Biological Wastewater Treatment

Proceedings of the Water Environment Federation, 2012

ABSTRACT In order to enhance the use of biofilm models for simulation of wastewater treatment pla... more ABSTRACT In order to enhance the use of biofilm models for simulation of wastewater treatment plants (WWTPs), model calibration is absolutely necessary. The aim of this work was to develop a calibration protocol for biofilm processes model with a help of the sensitivity analysis of the most important parameters implemented in BioWin® software. A case study of a circulating fluidized bed bioreactor (CFBBR) system used for biological nutrient removal (BNR) from municipal wastewater was used to verify and validate the proposed calibration protocol. Applying the various stages of the proposed biofilm calibration procedures enhanced the applicability of BioWin®, which was capable of predicting most of the performance parameters with an average percentage error (APE) of 0% to 20%. Although the calibrated model predicted most of the performance parameters, BioWin® predicted the total biomass and SRT based on active biomass only, whereas in the CFBBR both active as well as inactive biomass accumulated.

Research paper thumbnail of Influence of biofilm thickness on nitrous oxide (N2O) emissions from denitrifying fluidized bed bioreactors (DFBBRs)

Journal of Biotechnology, 2014

Research paper thumbnail of Mitigation of nitrous oxide (N2O) emissions from denitrifying fluidized bed bioreactors (DFBBRs) using calcium

Bioresource Technology, 2014

Research paper thumbnail of Liquid-solid circulating fluidized bed waste water treatment system for simultaneous carbon, nitrogen and phosphorus removal

Research paper thumbnail of Anaerobic digestion of municipal wastewater sludges using anaerobic fluidized bed bioreactor

Bioresource Technology, 2014

The anaerobic digestion of primary sludge (PS) and thickened waste activated sludge (TWAS) using ... more The anaerobic digestion of primary sludge (PS) and thickened waste activated sludge (TWAS) using an anaerobic fluidized bed bioreactor (AnFBR) employing zeolite particles as the carrier media was investigated at different organic loading rates (OLRs). PS was tested at OLRs from 4.2 to 39kgCOD/m(3)-d corresponding to hydraulic retention times (HRTs) from 1.0 to 8.9days. The highest COD removal and VSS destruction efficiencies for primary sludge of 85% and 88%, respectively, were achieved at an HRT of 8.9days and OLR of 4.2kgCOD/m(3)-d. For TWAS, VSS destruction efficiencies varied from 42% at an HRT of 2.6days and OLR of 13.1kgCOD/m(3)-d to 69% at an HRT of 8.8days and an OLR of 4.2kgCOD/m(3)-d. The first-order COD biodegradation rates in the AnFBR for PS and TWAS were 0.4d(-1) and 0.1d(-1), respectively, almost double the rates in conventional high-rate digesters.

Research paper thumbnail of Circulating Fluidized Bed Bioreactor: A Cost-effective Technology for Wastewater Treatment

Proceedings of the Water Environment Federation, 2012

ABSTRACT This study was focused on evaluating the economic feasibility of a newly developed techn... more ABSTRACT This study was focused on evaluating the economic feasibility of a newly developed technology, the Circulating Fluidized Bed-Bioreactor [CFBBR] compared to alternative technologies e.g. activated sludge process [AS], moving bed bioreactor [MBBR], and sequencing batch reactor [SBR] for municipal wastewater treatment. The CFBBR combines a circulating fluidized bed and a fixed-film process for an enhanced solid-liquid mass transfer that provides higher removal rates of nitrogen and phosphorous compared to the AS, MBBR, and SBR processes. Both labscale and pilot-scale CFBBRs demonstrated &gt; 90% COD, &gt; 80% N and 70% P removal at a hydraulic retention time of 2 h without primary clarification. Furthermore, the observed sludge yields of 0.12-0.16 g VSS/g COD consumed in the CFBBR resulted in 75% reduction in total biosolids production compared to conventional activated sludge non BNR treatment processes. The CFBBR demonstrated the potential for significant capital cost reduction, compliance with stringent regulations, reduction of biosolids, and up to 80% reduction in space requirements. Cost modules have been developed using CapDet Works 2.5 for the different processes employing reactor sizes designed for an average daily flow of 2.6 MGD (10,000 m3/d). The cost modules consist of screening, grit chamber, primary clarifier, biological nutrient removal units, secondary clarifier, UV-disinfection, thickening, anaerobic digestion, energy recovery, dewatering and sludge handling and disposal. The CFBBR was determined to be the most cost effective technology compared to the conventional BNR-AS and other available technologies for a completely new wastewater treatment facility. Even though the CFBBR does require high recirculation volume (12 times influent flow) to fluidize particles, energy consumption of 0.33 kWh/m3 in the CFBBR is less than the energy required in the MBBR (0.39kWh/m3), SBR (0.41 kWh/m3), and in the same range of the BNR-AS (0.31 kWh/m3) for biological nutrient removal from municipal wastewater.

Research paper thumbnail of Impact of alkaline-hydrolyzed biosolids (Lystek) addition on the anaerobic digestibility of TWAS in lab--and full-scale anaerobic digesters

Waste management (New York, N.Y.), 2014

The effect of different Lystek biosolids doses on the anaerobic digestability of thickened waste ... more The effect of different Lystek biosolids doses on the anaerobic digestability of thickened waste activated sludge (TWAS) was evaluated in a lab- and full-scale anaerobic digester. The overall findings of this study emphasize the beneficial impact of Lystek addition to the lab- and full-scale anaerobic digesters in terms of enhanced biogas production and increased volatile suspended solids reduction (VSSR) efficiency. Lystek added at 4% by volume to TWAS increased the methane yield from 0.22 to 0.26 L CH4/g VSSadded at an solids retention time (SRT) of 10 days, and from 0.27 to 0.29 L CH4/g VSS(added) at an SRT of 15 days. Furthermore, the VSSRs of 37% and 47% were observed for the TWAS, and the TWAS with 4% Lystek, while at an SRT of 15 days, the observed VSSR were 49% and 58%, respectively. The lab-scale study showed that the influence of Lystek addition on methane yield and solids destruction efficiencies was more pronounced at the shorter SRT, 20% enhancement (SRT of 10d) vs. 9% ...

Research paper thumbnail of Anaerobic digestibility of estrogens in wastewater sludge: Effect of ultrasonic pretreatment

Journal of Environmental Management, 2014

Research paper thumbnail of Degradation of estrone in water and wastewater by various advanced oxidation processes

Journal of Hazardous Materials, 2014

Research paper thumbnail of Comparison of Biofoulants in BNR-MBR and Conventional MBR (C-MBR) Systems

Proceedings of the Water Environment Federation, 2008

ABSTRACT

Research paper thumbnail of Treatment of Food Industry Waste by Bench-Scale Upflow Anaerobic Sludge Blanket-Anoxic-Aerobic System

Water Environment Research, 2006

An upflow anaerobic sludge blanket (UASB)-anoxicaerobic system was used for treatment of tomato a... more An upflow anaerobic sludge blanket (UASB)-anoxicaerobic system was used for treatment of tomato and bean processing wastewater. At various hydraulic retention times, ranging from 0.7 to 5 days, excellent removal of chemical oxygen demand (COD), biochemical oxygen demand (BOD), total suspended solids (TSS), ammonia-nitrogen (NH4-N), and total Kjeldahl nitrogen was achieved with final effluent BOD/TSS/NH4N concentrations of less than 15/15/1 mg/L. Biogas yield in the UASB reactor varied from 0.33 to 0.44 m3/kgCODremoved. The kinetics of anaerobic treatment were investigated. The yield coefficient was 0.03 gVSS/gCOD; maximum specific growth rate was 0.24 day(-1); Monod half velocity constant was 135 mgCOD/L; and specific substrate utilization rate was 3.25 gCOD/gVSS x d. Nitrification and denitrification kinetics were studied in batch experiments, and the rates were comparable with those in the continuous flow system.

Research paper thumbnail of Pilot-scale Experience with Biological Nutrient Removal and Biomass Yield Reduction in a Liquid-solid Circulating Fluidized Bed Bioreactor

Water Environment Research, 2010

A pilot-scale liquid-solid circulating fluidized bed (LSCFB) bioreactor was developed at the Adel... more A pilot-scale liquid-solid circulating fluidized bed (LSCFB) bioreactor was developed at the Adelaide Pollution Control Plant, London, Ontario, Canada, to study its commercial viability for biological nutrient removal. Lava rock particles of 600 microm were used as a biomass carrier media. The LSCFB removed approximately 90% organic, 80% nitrogen, and 70% phosphorus at loading rates of 4.12 kg COD/m3 x d, 0.26 kg N/m3 x d, and 0.052 kg P/m3 x d, and an empty bed contact time of 1.5 hours. Effluent characterized by &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 1.0 mg NH4-N/L, &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 5.0 mg NO3-N/ L, &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 1.0 mg PO4-P/L, &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 10 mg TN/L, &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 10 mg SBOD/L, and 10 to 15 mg volatile suspended solids (VSS)/L can easily meet the criteria for nonpotable reuse of treated wastewater. The system removed nutrients without using any chemicals, and the secondary clarifier removed suspended solids removal without chemicals. A significant reduction (approximately 75%) in biomass yield to 0.12 to 0.16 g VSS/g chemical oxygen demand (COD) was observed, primarily because of long biological solids retention time (SRT) of 20 to 39 days and a combination of anoxic and aerobic COD consumption.