Textile Sewage Research Articles

Performance improvement of textile wastewater treatment plant design by STOAT model simulation

Background: To control pollution, wastewater treatment from textile plays an important role in treating wastewater to meet quality standards before it is discharged into the environment. Without properly treated wastewater from the textile industry, it contains organic and inorganic pollutants that cause environmental problems such as water pollution, loss of marine life, and soil and air pollution. The aim of this study was to design and simulate a textile sewage treatment plant. Methods: This study was conducted by simulating the process and operation of a wastewater treatment plant using STOAT software. In addition, STOAT’s graphical and static data analysis models are efficient in removing multi-component pollutants from the textile industry. Results: Some pollutant parameters prior to the design model are suspended solids (SS) (260 mg/L), DS (3600 mg/L), ammonia (65 mg/L), biochemical oxygen demand (BOD) (430 mg/L), nitrate (35 mg/L), and dissolved Oxygen (DO) (12 mg/L). The wastewater of the simulation result of the sewage treatment plant model contained SS (3.3 mg/L), ammonia (25 mg/L), BOD (4 mg/L), nitrate (61.3 mg/L), and the removal percentage of total suspended solids (TSS), BOD, and Ammonia was 99.75, 99.1, 61.33 mg/L, respectively. Through the treatment process, Ammonia was oxidized and nitrification was processed rather than denitrification. Conclusion: Using the stoat modeling software, wastewater treatment plant design is very effective in removing contaminants from textile wastewater by selecting specific parameters.

Functionalized microspheres with co-participated lignin hybrids as a novel sorbents for toxic C.I. Basic Yellow 2 and C.I. Basic Blue 3 dyes removal from textile sewage

The paper presents the synthesis of novel adsorbents in spherical form based on divinylbenzene, ethylene glycol dimethylacrylate and triethoxyvinylsilane, and lignin or its modified form with ZrO2 and SiO2, as hybrid materials of well-defined microstructural factors. In the first stage of the experiment, lignin was mechanochemically combined with the inorganic oxides in form of zirconia and silica. Then, the obtained material was used as a modifier in the preparation of the functionalized polymeric microspheres using the suspension polymerization method. To confirm the chemical structure of the lignin-based hybrid modifiers and the polymeric sorbents, ATR-FTIR and XPS spectroscopy as well as SEM analysis were performed. In addition, the parameters of the porous structure were determined. It was shown that mainly physical interactions occur between the inorganic and organic components, resulting in the formation of class I hybrid systems. Subsequently, the functionalized polymeric microspheres were used as effective sorbents of hazardous C.I. Basic Yellow 2 (BY2) and C.I. Basic Blue 3 (BB3) days from textile wastewaters. Equilibrium data for the sorption of BY2 and BB3 by the newly designed adsorbents show that Freundlich isotherm model describes the experimental data more appropriate than the Langmuir or Dubinin–Radushkevich ones. The Freundlich constant related to adsorption capability, kF, enlarged with rising amount of lignin, zirconia and silica, from 42.3 to 83.5 mg1–1/n L1/n/g for BB3 and from 11.1 to 45.7 mg1–1/n L1/n/g for BY2. Kinetic studies revealed favorable uptake of 50 mg/L BB3 during the first 60 min of phase contact time, compared with BY2. Anionic and non-ionic surfactants (0.25 g/L) and NaCl (25 g/L) slightly decreased dyes (50 mg/L) sorption from dyeing baths, and their retention was significantly reduced when a cationic surfactant was present in the bath. Desorption of BB3 and BY2 dyes from the hybrids, with yield in the ranges 20.8–32.0% and 24.8–99.0% respectively, was achieved applying 1 M HCl in the presence of 50% v/v methanol.

Optimization of the biodecolorization activity of the Ayapers dye removal by Halmonas sp. isolated from Urmia Lake

Background: Among chemical dyes, Azo dyes, as environmental synthetic pollutants, are most commonly used in a bunch of different colors in different industries, especially in textile industry to a large extent. Methods: Due to some limitation and difficulties to remove these pollutants from the environment, the biological filtering method, as the economically and optimal methods, are preferred. Using the Taguchi method and evaluation of such factors in the environment as temperature pH, color density and concentration of salt, we studied the optimal condition of Halomunas PTCC1132 bacteria decolorization in order to compare it with the Aryapress dye removal from aquatic environment. Therefore, 16 experiments were designed according to Array Table in 4 factors and 4 levels. The results were then analyzed using a computer the program named Qualitek-4. Results: The results showed that this salt, loving bacterium Halomonas strain PTCC1714, has the ability of bleaching in a wide range of salts till 20%, pH (5-9) and dye tolerance up to 5 gr/lit (500 ppm), and has the highest rate of decolorization in 100 ppm. Conclusions: According to the results with an optimal growth condition- the temperature of 40c, pH of 7.5, and the salt concentration of 10% up to 93% - the strain was capable of removing the Azo dye Aryapress color with the concentration of 100 ppm which is a considerable amount and can be used in biological treatment of industrial textile sewage.

Flocculant-Assisted Synthesis of Graphene-Like Carbon Nanosheets for Oxygen Reduction Reaction and Supercapacitor.

The rational treatment of hazardous textile sludge is critical and challenging for the environment and a sustainable future. Here, a water-soluble chitosan derivative was synthesized and used as an effective flocculant in removal of reactive dye from aqueous solution. Employing these chitosan-containing textile sludges as precursors, graphene-like carbon nanosheets were synthesized through simple one-step carbonization with the use of Fe (III) salt as graphitization catalyst. It was found that the resultant graphene-like carbon nanosheets material at thickness near 3.2 nm (NSC-Fe-2) showed a high graphitization degree, high specific surface area, and excellent bifunctional electrochemical performance. As-prepared NSC-Fe-2 catalyst exhibited excellent oxygen reduction reaction (ORR) activity (onset potential 1.05 V) and a much better methanol tolerance than that of commercial Pt/C (onset potential 0.98 V) in an alkaline medium. Additionally, as electrode materials for supercapacitors, NSC-Fe-2 also displayed an outstanding specific capacitance of 195 F g−1 at 1 A g−1 and superior cycling stability (loss of 3.4% after 2500 cycles). The good electrochemical properties of the as-prepared NSC-Fe materials could be attributed to the ultrathin graphene-like nanosheets structure and synergistic effects from codoping of iron and nitrogen. This work develops a simple but effective strategy for direct conversion of textile sewage sludge to value-added graphene-like carbon, which is considered as a promising alternative to fulfill the requirements of environment and energy.

Elaboration of an Efficiency Indicator of Treatment Industrial Waste Water by Ozone

While developing the technology of using ozone for the destruction of organic substances in industrial wastewater, it is important to determine the required dose of ozone and the period of water treatment. In some cases, for example, when the dyes are destroyed in textile sewage, the color reduction occurs earlier than the decomposition of the organic matter of the dyes. Thus, there is a need to control the purification process by several indirect indicators, such as oxidability, total organic carbon content and etc. There is also the difficulty in determining the required dose of ozone for the decomposition of contaminants. We carried out experimental researches and examined the material balance of the ozonation process. A generalized method for determining the consumption of ozone in the oxidation of contaminants in sewage waters is proposed. The indicator "chemical demand of ozone" is used. During the trial ozonation of waste water the method allows to obtain the dependence of ozone consumption on the processes of pollution destruction and to determine the required specific dose of ozone for the destruction of contaminants.

The Estimation Method of the Ozone Treatment Effectiveness of Wastewater Containing Dyes

One of the applications of ozone for wastewater treatment is the destruction of difficult-oxidizing organic contaminants, including dyes. An important stage of development of water purification technology is the determination of the required degree of pollution destruction, effective doses of ozone and the period of water treatment. For example, in some cases when the dyes are degraded in textile sewage, the color reduction occurs with a slight decomposition of the organic substance of the dyes. The purification process is controlled by several indirect indicators, such as oxidizability, total organic carbon content, etc. We have conducted experimental researches and have studied the material balance of the ozonation process for wastewater containing dyes. Generalized method for determination of the consumption of ozone in the oxidation of contaminants in sewage waters and the technological indicator “chemical demand of ozone” are proposed. The method is quite universal and allows, while carrying out trial ozonation of water, to obtain dependence of ozone consumption for the processes of pollution destruction and determine the required specific dose of ozone.

Optimum BET surface areas for activated carbon produced from textile sewage sludges and its application as dye removal

The purpose of this experimental study is to determine optimum preparation conditions for activated carbons obtained from textile sewage sludge (TSS) for removal of dyes from aqueous solutions. The textile sewage sludge activated carbon (TSSAC) was prepared by chemical activation with potassium hydroxide using Response Surface Methodology (RSM). The most influential factor on each experimental design responses was identified via ANNOVA analysis. Based on the central composite design (CCD), quadratic model was developed to correlate the preparation variables for one response which is the Brunauer–Emmelt–Teller (BET) surface area. RSM based on a three-variable CCD was used to determine the effect of pyrolyzed temperature (400–700 °C), carbonization time (45–180 min) and KOH: weight of TSS (wt%) impregnation ratio (0.5:1–1.5:1) on BET surface area. According to the results, pyrolyzed temperature and impregnation ratio were found as the significant factors for maximizing the BET surface area. The major effect which influences the BET surface area was found as pyrolyzed temperature. Both carbonization time and impregnation ratio of KOH had no significant effect. The optimum conditions for preparing TSSAC, based on response surface and contour plots, were found as follows: pyrolyzed temperature 700 °C, carbonization time of 45 min and chemical impregnation ratio of 0.5. The maximum and optimum BET surface area of TSSAC were found as 336 m2/g and 310.62 m2/g, respectively. Synozol Blue reactive (RSB) and Setapers Yellow–Brown (P2RFL) industrial textile dyes adsorption capacities were investigated. As expected the TSSAC which has the biggest BET surface area (336 m2/g) adsorbed dye best. The maximum (RSB) and (P2RFL) uptake capacities were found as 8.5383 mg/g and 5.4 mg/g, respectively. The results of this study indicated the applicability of TSSAC for removing industrial dyes from aqueous solution.

Strontium ion removal from Aqueous Solution using Activated Carbon Produced from Textile Sewage Sludges: Effect of ZnCl2

Strontium ion removal from Aqueous Solution using Activated Carbon Produced from Textile Sewage Sludges: Effect of ZnCl2

Relationship between protozoan and metazoan communities and operation and performance parameters in a textile sewage activated sludge system

The present study aims at investigating the possibility of assessing performance and depuration conditions of an activated sludge wastewater treatment plant through an exploration of the microfauna. The plant, receiving textile industrial (70%) and domestic (30%) sewage, consists of a two-step biological depurating plant, with activated sludge followed by a percolating system. A total of 35 samples were analyzed during five months, and 30 taxa of protozoa and small metazoa were found. Epistylis rotans, Vorticella microstoma, Aspidisca cicada and Arcella sp. were the most frequent protozoa identified. Several significant correlations between biological, physical–chemical and operational parameters were determined, but no significant correlations could be established between biological parameters and removal efficiencies. The Sludge Biotic Index (SBI) reflected the overall state of the community but only presented statistically significant correlations with the influent total suspended solids (TSS), total suspended solids in mixed-liquor (MLTSS) and dissolved oxygen (DO). The determination of key groups and taxa along with general community parameters showed to have potential value as indicators of the depuration conditions. Despite the impossibility of correlating biological parameters and the removal efficiencies, the present study attests the value of the microfauna to assess the operation of the activated sludge systems even in the case of non-conventional plants and/or plants receiving industrial sewage.

UV-initiated polymerization of hydrophobically associating cationic flocculants: Synthesis, characterization, and dewatering properties

A new composite flocculant was synthesized by the copolymerization of acrylamide (AM), acryloyloxyethyltrimethyl ammonium chloride (DAC), and butylacrylate (BA) under ultraviolet (UV) radiation with 2,2′-azobis(2-methylpropionamide) dihydrochloride (V-50) as photo-initiator. This flocculant was named P(AM–DAC–BA). Nuclear magnetic resonance hydrogen spectroscopy (1H NMR), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) were used to observe the structure and morphology of P(AM–DAC–BA). Parameters affecting the intrinsic viscosity ([η]) and conversion of P(AM–DAC–BA), such as monomer concentration, photo-initiator concentration, pH, illumination time, and incident light intensity in a quartz or glass reactor were examined. Results showed that the optimum conditions were 30wt% total monomers, 2.0wt% hydrophobic monomer, 0.5wt‰ photo-initiator, pH 4.4, 100min of illumination time, and 1160μWcm−2 incident light intensity. To study the dewatering performance of P(AM–DAC–BA), the textile sewage sludge dewatering was evaluated by measuring both the residual turbidity and moisture content of the filter cake. At 50mgL−1 P(AM–DAC–BA) and pH 11.6, the residual turbidity of the supernatant and moisture content of the dewatered filter cake reached 5.5NTU and 73.2%, respectively. Dewatering tests demonstrated the superiority of P(AM–DAC–BA) flocculant synthesized in the quartz reactor over that synthesized in the glass reactor.

Influence of Coagulant Species on Sulfur Oxide (SOx) Emission from the Textile Sewage Sludge Combustion

Influence of Coagulant Species on Sulfur Oxide (SOx) Emission from the Textile Sewage Sludge Combustion

Adsorption of strontium from aqueous solution using activated carbon produced from textile sewage sludges

Different types of activated carbons were prepared by changing the activation temperatures (400–700°C) and impregnation ratio (sewage sludge: KOH; 1:1, 1:2) and the removal of Sr+2 from aqueous solution was determined. The maximum adsorption yield (12.11mg/g) was obtained at 500°C for 1h carbonization conditions with impregnation ratio of 1:1. The affecting parameters were analyzed by using central composite design method. The selected parameters were initial pH, temperature, initial strontium concentration and carbon dosage. The analysis of variance was performed in 95% confidence level and checked to fitting of experimental value and predicted value. The significant F was P<0.05 with a model F value of 19.94 which revealed that this regression is statistically significant. The results of regression analysis indicated that pH and temperature parameters were not individually statistically significant for Sr+2sorption. However, the efficiency of strontium sorption increases with the increase in carbon dosage and decreases with the Sr+2 concentration. Influences of initial pH and temperature, pH and Sr+2 concentration, temperature and carbon dosage and Sr+2 concentration and carbon dosage on the adsorption process were considered statistically significant. Adsorption of strontium was described by Freundlich isotherm as a physical adsorption (E=7.2kJ/mol). The adsorption reactions were calculated as endothermic, spontaneous and favorable reactions.

The Evaluation of Chemical Coagulation for Treatment of Kashan Textile Sewage

The Evaluation of Chemical Coagulation for Treatment of Kashan Textile Sewage