scholarly journals Pretreatment of printing and dyeing wastewater by Fe/C micro-electrolysis combined with H2O2 process

2018 ◽  
Vol 2017 (3) ◽  
pp. 707-717 ◽  
Author(s):  
Yan Wang ◽  
Xianwei Wu ◽  
Ju Yi ◽  
Lijun Chen ◽  
Tianxiang Lan ◽  
...  

Abstract A novel iron-carbon (Fe/C) micro-electrolysis combined with H2O2 (ICMH) process was proposed to pretreat the printing and dyeing wastewater (PDW), using a micro-electrolysis filling. The effects of H2O2 concentration, reaction time, initial pH, and Fe/C dosage on chemical oxygen demand (COD) removal rate of PDW were optimized by response surface methodology (RSM). The maximum COD removal rate was approximately 77.65% after 186 min treatment, when the concentration of H2O2, initial pH and the dosage of Fe/C were 8.88 g/L, 1.5 and 837 g/L, respectively. Analysis of variance (ANOVA) showed a high coefficient of determination value (R2 = 0.9780). And H2O2 concentration and initial pH were the key factors to improve the treatment effect. UV-Vis spectra indicated that a significant blue shift at 220 nm, attributing that fused aromatic hydrocarbons were degraded effectively. 3D-EEM spectra analysis showed that the water samples of PDW mainly contained three kinds of organic matter: refractory fulvic acid, soluble microbial metabolites and aromatic proteins, and the degradation rate of these was 81.76%, 53.78% and 70.83%, respectively.

2021 ◽  
Vol 261 ◽  
pp. 04005
Author(s):  
Emmanuel Nkudede ◽  
Husseini Sulemana ◽  
Bo Zhang ◽  
Kaida Zhu ◽  
Shan Hu ◽  
...  

Owing to its widespread and persistent usage, methylene blue (MB) is an environmental substance, mostly found in the printing and dyeing industry that raises concerns in the environment recently by posing significant threat to human life and the ecosystem as a whole. Thus, there is the need to effectively manage and treat the wastewater from these industries before reaching to the available water sources. Ozonation treatment is very efficient in treating printing and dyeing wastewater (MB) and can be greatly improved by using micro-bubble technology. Microbubble dissolution is an effective way to improve the rate of ozone mass transfer. To discover these properties, a method was used to improve the mass transfer of ozone microbubbles, which was used to effectively treat simulated printing and dyeing wastewater. We investigated the effects of pH, water temperature, ozone flow, and other conditions on the dissolution and attenuation properties of ozone in methylene blue microbubble solutions. Treatment of simulated printing and dyeing wastewater (methylene blue) was investigated under various initial pH and ozone flow rates. A catalytic exhibition was performed towards the decolorization of methylene blue (MB) concentrations and the corresponding COD removal efficiency. Ozone depletion and pH levels played key roles in MB degradation. Under high pH level of 11.01, the rate of removal of COD was 93.5%. Ozone dosage also has direct effect on COD removal efficiency and decolorization. Higher ozone flow rates, 0.4 L/min and 0.5 L/min recorded more than 94% degradation of COD thus very effective and efficient. Also, ozone flow rates 0.3 L/min, 0.4 L/min and 0.5 L/min with initial pH, 7.03, 6.63 and 6.36 decreased to 3.43, 3.49 and 3.44 after reaction processes which clearly shows that with high ozone dosage, pH reduces considerably.


2011 ◽  
Vol 347-353 ◽  
pp. 1949-1952 ◽  
Author(s):  
Liang Li ◽  
Bing Zhe Xu ◽  
Chang Yu Lin ◽  
Xiao Min Hu

Zidovudine wastewater is difficult to biodegradation due to high COD and toxicity. The synergetic treatment of Zidovudine wastewater by Ultrasonic and iron-carbon micro-electrolysis technology was studied. The influence of initial pH, reaction time, mass ratio of iron and carbon and mass ratio of iron and water on degradation rate of COD was researched. The result showed that the COD removal rate was only about 54.3% and the degradation speed is very slow when iron-carbon micro-electrolysis treated Zidovudine wastewater separately. However, when ultrasonic synergy micro-electrolysis to treat Zidovudine wastewater, the COD removal rate could was up to 85% and the reaction time was also decreased. Moreover, the BOD5 / COD rose from 0.15 to 0.35, which meant the wastewater became easily biodegradable.


2013 ◽  
Vol 68 (1) ◽  
pp. 257-260 ◽  
Author(s):  
Yujie Feng ◽  
Junfeng Liu ◽  
Limin Zhu ◽  
Jinzhi Wei

The clomazone herbicide wastewater was treated using a combined technology composed of electrochemical catalytic oxidation and biological contact degradation. A new type of electrochemical reactor was fabricated and a Ti/SnO2 electrode was chosen as the anode in electrochemical-oxidation reactor and stainless steel as the cathode. Ceramic rings loaded with SnO2 were used as three-dimensional electrodes forming a packed bed. The operation parameters that might influence the degradation of organic contaminants in the clomazone wastewater were optimized. When the cell voltage was set at 30 V and the volume of particle electrodes was designed as two-thirds of the volume of the total reactor bed, the chemical oxygen demand (COD) removal rate could reach 82% after 120 min electrolysis, and the ratio of biochemical oxygen demand (BOD)/COD of wastewater increased from 0.12 to 0.38. After 12 h degradation with biological contact oxidation, the total COD removal rate of the combined technology reached 95%, and effluent COD was below 120 mg/L. The results demonstrated that this electrocatalytic oxidation method can be used as a pretreatment for refractory organic wastewater before biological treatment.


Archaea ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Shuo Wang ◽  
Jianzheng Li ◽  
Guochen Zheng ◽  
Guocheng Du ◽  
Ji Li

Hydrogen-producing acetogens (HPA) have a transitional role in anaerobic wastewater treatment. Thus, bioaugmentation with HPA cultures can enhance the chemical oxygen demand (COD) removal efficiency and CH4yield of anaerobic wastewater treatment. Cultures with high degradation capacities for propionic acid and butyric acid were obtained through continuous subculture in enrichment medium and were designated as Z08 and Z12. Bioaugmentation with Z08 and Z12 increased CH4production by glucose removal to 1.58. Bioaugmentation with Z08 and Z12 increased the COD removal rate in molasses wastewater from 71.60% to 85.84%. The specific H2and CH4yields from COD removal increased by factors of 1.54 and 1.63, respectively. Results show that bioaugmentation with HPA-dominated cultures can improve CH4production from COD removal. Furthermore, hydrogen-producing acetogenesis was identified as the rate-limiting step in anaerobic wastewater treatment.


2011 ◽  
Vol 415-417 ◽  
pp. 438-441
Author(s):  
Jin Xia Yan ◽  
Dong Fang Li ◽  
Shao Feng Dong

The printing and dyeing wastewater was treated by internal electrolysis method. The results show the chromaticity removal rate was up to 98.53 percent and COD removal rate 85.98 percent under the optimum conditions of wastewater pH 4, reaction time 30 minutes, the electric conductivity 1450μm/cm, the value BOD5/COD increases from 0.34 to 0.51. Moreover, the pH, Fe2+ concentration and absorbance of wastewater changed in the process, the mechanism of that was also analyzed.


2022 ◽  
Vol 9 ◽  
Author(s):  
Shuai Zhang ◽  
Huixue Ren ◽  
Kaifang Fu ◽  
Wenqing Cheng ◽  
Daoji Wu ◽  
...  

The printing and dyeing wastewater produced by different dyes, as well as different printing and dyeing processes, have different components. These wastewater have high toxicity, high organic concentration, and deep chromaticity. Ozone catalytic oxidation is a very promising technical method for wastewater treatment. In this paper, Mn/Mg/Ce ternary catalyst was prepared, and the ozone catalytic oxidation treatment of actual and simulated printing and dyeing wastewater was performed to study the performance of four different carrier catalysts, namely, molecular sieve (MS), silica gel (SG), attapulgite (ATP), and nano alumina (Al2O3), by simulated dynamic test. The effects of reaction time, pH, and catalyst dosage on methyl orange degradation were studied. The results showed that under the optimum treatment conditions (120 min, pH 11, and 12.5 g/L catalyst dosage), the degradation rate of methyl orange reached 96% and the removal rate of the chemical oxygen demand of printing and dyeing wastewater reached 48.7%. This study shows that the treatment effect of ozone catalytic oxidation on printing and dyeing wastewater is remarkably improved after catalyst addition. This study provides a new choice of ozone catalyst for the degradation of printing and dyeing wastewaters in the future.


2019 ◽  
Vol 9 (3) ◽  
pp. 212-221
Author(s):  
Fatima Erraib ◽  
Khalid El Ass

Box–Behnken response surface design was successfully employed to optimize and study the olive mill wastewater (OMW) treatment by electrocoagulation (EC) process. The influence of four decisive factors were modelled and optimized to increase the removal of chemical oxygen demand (COD). The Box–Behnken design (BBD) results were analyzed and the second-order polynomial model was developed using multiple regression analysis. The model developed from the experimental design was predictive and a good fit with the experimental data with a high coefficient of determination (R2 ) value (more than 0.98). The optimal operating conditions based on Derringer’s desired function methodology are found to be; initial pH of 4.4, a current density of 27.6 mA/cm2 , electrolysis time of 14.1 min, and chloride concentration of 3.2 g/L. Under these conditions, the predicted COD removal efficiency was found to be 67.14% with a desirability value of 0.94. These experimental results were confirmed by validation experiments and proved that Box–Behnken design and response surface methodology could efficiently be applied for modelling of COD removal from OMW.


2001 ◽  
Vol 43 (11) ◽  
pp. 51-58 ◽  
Author(s):  
P. C. Male ◽  
W. A. Pretoruis

Wastewater high in phenolic content (948 mg/l) and dissolved solids (5.4 g/l) had to be treated to remove most of the organic material and toxic compounds. A laboratory scale High Pressure (3 bar) Bioreactor (HPB) was developed and operated to treat the wastewater using a ceramic ultra filtration membrane as biomass separator. The performance of the system was compared to a normal activated sludge plant (ASP) using sludge settling for separation. The HPB was more stable than the ASP, which twice became unstable with a resulting biomass loss. Both reactors removed 90% of the chemical oxygen demand (COD) loading, reducing the phenol concentration below 20 mg/l. The maximum COD removal rate of the HPB was 28 kg/m3.d compared to 15 kg/m3.d of the ASP, while the HPB achieved 16-32 times better oxygen transfer than the ASP. It was concluded that the HPB was the preferred treatment system compared to the ASP, when treating high strength inhibitory wastewaters, due to its stable operating performance and high COD removal rate.


1993 ◽  
Vol 28 (3) ◽  
pp. 597-620 ◽  
Author(s):  
Catherine N. Mulligan ◽  
Bechara F. Safi ◽  
Jacques Meunier ◽  
Jean Chebib

Abstract The SNC multiplate reactor (1,200 L) has been developed and tested to determine chemical oxygen demand (COD) removal, nutrient requirement, and gas production from the anaerobic treatment of effluents generated at the Agropur (Notre Dame-du-Bon-Conseil, Quebec) and Nutrinor cheese dairies (Chambord, Quebec). At the Agropur plant, wastewater (3,000 mg/L COD) was treated the best at a retention time of 12 h. Using this retention time, effluents containing whey with organic loads of 10.2 to 41.6 kg COD/m3/day could be treated at a 84% COD removal rate. When the reactor was subjected to shock by increasing the organic load suddenly from 8.9 to 31 kg COD/m3/day, the total COD removal decreased to 72% and then returned to 86% after 7 days. Hydrology tests indicated that the reactor functions as a series of completely mixed stirred tanks. At Nutrinor, using a 12-h retention time and diluted whey permeate (20,000 mg/L COD), total COD removal was 86% and gas production was 12.0 m3/m3/day for a loading of 36.5 kg COD/m3/day. Nutrient supplementation was not required. For experiments performed with different proportions of wastewater (2,000 mg/L COD) to whey permeate (70,000 mg/L COD) results of 89% total and 93% soluble COD removal with a gas production of 11 m3/m3/day for a loading of 25 kg COD/m3/day were obtained. Retention times were varied from 18 to 60 h to correspond to initial CODs of 20,000 to 70,000 mg/L. In conclusion, this reactor functions in a superior manner to other published anaerobic treatment systems.


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