Coagulation/flocculation process for dye removal using sludge from water treatment plant: Optimization through response surface methodology (original) (raw)
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2017
In this research, the potential of aluminum-based water treatment residual (WTR) discharged from the water treatment plant has been evaluated as a coagulant for color removal from cationic and anionic dye solutions. The sample of water treatment residuals (WTR) was collected from water treatment plant (Nigdi, Pune) where Poly Aluminum Chloride (PAC) is used as coagulant in the coagulation/flocculation process. The effects of initial pH, initial dye concentration and WTR dosage were studied. The results have shown that maximum color removal of 81.08, 77.88 and 72% for anionic dye and 94.54, 91.77 and 84.53% for cationic dye were obtained at initial dye concentrations of 25, 50 and 75mg/L, respectively, at pH 3.0 and WTR dose of 120mg/L. Although lower amount of WTR were required for the removal of dyes from wastewater, the reuse of WTR as a low cost material can offer several advantages such as higher efficiency of cationic an anionic dye color removal and economic savings on overall...
2015
Coagulation and flocculation are most widely methods used for dye and pollution removal from various wastewaters. The aim of this study is efficiency comparison of inorganic coagulant (Alum and Ferric Cchloride) for treatment of textile factory wastewater. The appropriate coagulant was selected at optimum condition for treatment of textile's factory wastewater by measuring of dye, COD, BOD5 and TSS parameters. The different pH (4, 5, 6, 7, 8 and 9) was used for determine the optimum pH. Totally, 240 samples were collected and exanimated according the standard methods of wastewater and water tests. Results showed that the ferric chloride has more removal efficiency than alum in removal of COD, TSS and dye. The most removal of COD, TSS and dye using alum was obtained 36, 19 and 68.8 while for ferric chloride was obtained 72, 60 and 98 respectively. The optimum pH 7 and 5 were obtained for alum and ferric chloride respectively. Based on the results, it can be concluded that COD, TS...
Decolorization of an acidic dye from synthetic wastewater by sludge of water treatment plant
In this research, sludge of Jalaliyeh water treatment plant in Tehran was used as an alternative coagulant for the removal of a specific type of acid dye (acid red 119 (AR119)). For this purpose, the effect of initial pH, coagulant dose and initial dye concentration on dye removal efficiency were investigated. Results showed that the dye removal rates were largely dependent on pH. When the solution pH was increased from 3 to 8, the dye removal rates decreased from 96.3% to 2.3%. The removal efficiencies of the dye using 130-350 mg dried sludge/L were more than 90% at initial pH =3. With the increase of initial dye concentration in the range of 10-200 mg/L, the removal efficiency increased at first (from 10-40 mg/L) and then declined. So, sludge of Jalaliyeh water treatment plant may be considered as an appropriate coagulant for the removal of AR119 dye.
Development of Treatment Technology for Dye Containing Industrial Wastewater
Journal of Scientific Research, 2010
The removal of Congo red was carried out by heating with changing pH, using coagulant and by adsorption. Acidic pH was favorable for the removal of Congo red by heating. It is possible to remove a major portion of Congo red just by decreasing the pH (< 4). Removal studies suggest that coagulation might be the major mode of dye removal. It is becoming a promising alternative to replace or supplement the present dye removal processes from wastewater. In these studies, removal of Congo red from aqueous solution by coagulation and flocculation was investigated. Treatment with alum and lime was found to be the most effective. Activated charcoal is also an effective adsorbent for the removal of Congo red. From the isotherm (Langmuir and Freundlich) and kinetics study we find that the Congo red-activated charcoal system has high affinity and capacity.
Study of chemical coagulation conditions for a disperse red dye removal from aqueous solutions
Membrane Water Treatment, 2018
Coagulation process using aluminum sulfate (Al 2 (SO 4) 3) and ferric chloride (FeCl 3) was employed as a treatment method for decolorization of a synthetic textile wastewater containing red dye in this paper. Factors such as initial pH, coagulant dosage, initial concentration, conductivity and mixing conditions that influence color removal efficiency were experimentally tested. It was found that Al 2 (SO 4) 3 is more efficient than FeCl 3 as coagulant. When 40 mgL-1 aluminum sulfate was used, results showed that color induced by the red dye was efficiently removed ( 90 %) and was obtained in a large range of initial pH from 4 to 8 with, and for a dye concentration lower than 235 mg L-1. After addition of the coagulant, the medium had to be mixed for 30 min at 60 rpm, then allowed to settle for 40 min. The effects of water conductivity in the range 0.035-2.42 mS cm-1 and dye concentration up to 380 mg L-1 were also followed and discussed.
Surfaces and Interfaces, 2020
The aims of this research work was to investigate the potentials of raw and calcined iron hydroxides/oxides sludge adsorption for DR28 dye removal. The adsorbent is prepared from electro-coagulated (EC) sludge in industrial wastewater treatment plant, as a Nobel adsorbent for decolorizing direct red 28 dye (DR28). The EC sludge adsorbent were prepared with soaking processes and calcination in a range of temperature. The surface properties of raw and calcined EC sludge adsorbent were examined using Zeta Potential, XRD and FTIR. Basic (effect of solution pH, temperature, initial dye concentration) operation parameters were examined for raw and calcined EC sludge adsorbent. The diffraction patter suggests that the crystalline hematite are produced during calcination and increases its intensity as temperature increases. Langmuir and Freundlich Equation were used to model the adsorption equilibrium; and pseudo first and second order Equation were used to model the ad-sorption kinetics. The results suggested that the adsorption of DR28 dye is chemisorption, the interaction between the adsorbent surfaces with dye is strong. The Langmuir adsorption capacity of DR28 dye with raw and calcined EC sludge adsorbent was calculated as 1.262 mg/g and 1.252 mg/g respectively with experimental conditions: mixing time=20 min, adsorbent dosage=0.5 grams, initial dye concentration= 20 mg/L and solution pH =2 at ambient temperature. The adsorption kinetics model data were consistent with the pseudo-second-order. The removal efficiency of 97% was recorded at pH 2, ambient temperature 20 mg/l concentration and 1 g/100 ml for 1 hour. High direct red 28 dye uptake capability and cost-effectiveness of sludge utilization from textile wastewater treatment plant make it potentially attractive for dye removal.
Efficiency of the coagulation/flocculation method for the treatment of dyebath effluents
Dyes and Pigments, 2005
Textile dyeing processes are among the most environmentally unfriendly industrial processes, because they produce coloured wastewaters that are heavily polluted with dyes, textile auxiliaries and chemicals. The coagulation/flocculation method was studied as a wastewater treatment technique for the decolourization of residual dyebath effluents after dyeing cotton/polyamide blends using reactive and acid dyes. It was discovered that a combination of aluminium sulphate and a cationic organic flocculant yields an effective treatment for residual dyebath wastewaters since almost complete decolourization was achieved, TOC, COD, AOX, BOD and the anionic surfactants were reduced and the biodegradability was increased.
Removal of dyes from industrial waste water (Textile) by using sludge
The removal of dyes from textile dying wastewater by recycled alum sludge (RAS) generated by the coagulation process itself was studied and optimized. One hydrophobic and one hydrophilic dye were used as probes to examine the performance of this process. It was found that RAS is a good way of removing hydrophobic dye in wastewater, while simultaneously reducing the fresh alum dosage, of which one third of the fresh alum can be saved. The back-diffusion of residue dye from the recycling sludge is detected but is easily controlled as long as a small amount of fresh alum is added to the system. The use of RAS is not recommended for the removal of hydrophilic dyes, since the high solubility characteristics of such dyes can cause deterioration in the water quality during recycling.
ORIGINAL ARTICLE Introduction: Since some dyes and their metabolites have toxicity and carcinogenicity potential, and are dangerous to the health of different living creatures, discharge of untreated wastewaters containing large concentrations of dye compounds into water resources is one of the important environmental problems. Therefore, in this research, the efficiency of chemical coagulation process was investigated using ferric chloride coagulant to remove Direct Red 23 dye from colored wastewater. Materials and Methods: In the experiments, a Jartest device was used and the effect of different parameters including the dose of the coagulant (20-200 mg/L), pH (3-10), and initial concentration of the dye (25-200 mg/L) on the efficiency of chemical coagulation process for removal of the dye was examined. Further, the final pH of the wastewater was investigated and the optimal conditions were determined. Results: The results indicated that the optimal dose of ferric chloride coagulan...
Removal of Dyes by Aqueous Mixed Coagulants
ASEAN Journal of Chemical Engineering
Alum, MgCl2, and mixtures of alum and MgCl2 have been used as coagulant to remove coloring matter in the reactive dye Levafix Brill Blue EBRA. The jar test was used to determine the effectiveness and the optimal condition of the coagulation process in terms of pH of the coagulation process, coagulant dosage, percentage color removal, and floc settling time. Coagulant dosages of 1,000-5,000 ppm were studied. The treatment of textile industry wastewater was done in the treatment plant of a printing mill. The results showed that coagulation by MgCl2 and alum occurs at the removal pH ranges of 10.5-11.0 for MgCl2 and 4.0-6.0 for alum. The mixtures of MgCl2 and alum gave two distinct effective color-removal zones at pH 4-5.5 and pH 8-9.5. The addition of alum to MgCl2 shifted the optimal pH of MgCl2 from 10.5-11. 0 to 8. 0-9.5. The alum dose of 1,000-3,000 ppm in the coagulant mixture increased by 10-25 % the color removal in the alkaline zone. Floc settling time was found to (a) increas...