A comparative treatment of bleaching wastewater by physicochemical processes

2017 ◽  
Vol 76 (9) ◽  
pp. 2367-2379 ◽  
Author(s):  
Ninad Oke ◽  
Swati Singh ◽  
Anurag Garg
Keyword(s):  
Mixing Time ◽  
Oxygen Demand ◽  
Chloride Ion ◽  
Paper Mill ◽  
Ion Concentration ◽  
Treated Wastewater ◽  
Molar Ratio ◽  
Chlorinated Organic Compounds ◽  
H2o2 Treatment ◽  
Toc Removal

Abstract The bleaching effluent discharged from a pulp and paper mill contains chlorinated organic compounds which are toxic to living matter. Physicochemical treatments such as coagulation and different advanced oxidation processes (AOPs) were employed for combined bleaching effluent generated from the first two stages (i.e. chlorination and alkali extraction) (pH = 3.5, chemical oxygen demand (COD) = 1,920 mg/L, and total organic carbon (TOC) = 663 mg/L). At optimum conditions (pH = 7.5, polyaluminium chloride (PAC) dose = 3.84 g/L and slow mixing time = 25 min), ∼68% removal in UV254 and ∼23% TOC removal was obtained during coagulation. Among various AOPs, UV/Fe2+/TiO2/H2O2 system showed the highest TOC and COD removals (∼78%) after 2 h duration (Fe2+:H2O2 molar ratio = 1:100). After the AOP process, chloride ion concentration and biodegradability of the treated wastewater was increased to 2,762 mg/L and 0.46 from an initial value of 2,131 mg/L and 0.29, respectively. The wastewater and sludge analysis showed oxidation and adsorption as the major mechanisms for organics removal. Upon reuse of the regenerated catalysts, TOC removal was reduced significantly. It was found that three times more sludge per unit TOC removal was generated after coagulation in comparison to that produced after UV/Fe2+/TiO2/H2O2 treatment.

Optimization and statistical analysis of sono-Fenton treated wastewater of food industry using reactor by response surface method

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Vijay A. Juwar ◽  
Ajit P. Rathod
Keyword(s):  
Reaction Time ◽  
Response Surface ◽  
Food Industry ◽  
Batch Reactor ◽  
Oxygen Demand ◽  
Volume Ratio ◽  
Cod Removal ◽  
Treated Wastewater ◽  
Experimental Result ◽  
Molar Ratio

Abstract The present study deals with the treatment of complex waste (WW) treated for removal of chemical oxygen demand (COD) of the food industry by a sono-Fenton process using a batch reactor. The response surface methodology (RSM) was employed to investigate the five independent variables, such as reaction time, the molar ratio of H2O2/Fe2+, volume ratio of H2O2/WW, pH of waste, and ultrasonic density on COD removal. The experimental data was optimized. The optimization yields the conditions: Reaction time of 24 min, HP:Fe molar ratio of 2.8, HP:WW volume ratio of 1.9 ml/L, pH of 3.6 and an ultrasonic density of 1.8 W/L. The predicted value of COD was 91% and the experimental result was 90%. The composite desirability value (D) of the predicted percent of COD removal at the optimized level of variables was close to one (D = 0.991).

scholarly journals Impact on Gaza aquifer from recharge with partially treated wastewater

2011 ◽  
Vol 1 (1) ◽  
pp. 36-44 ◽  
Author(s):  
Sami M. Hamdan ◽  
Abdelmajid Nassar ◽  
Uwe Troeger
Keyword(s):  
Water Resources ◽  
Gaza Strip ◽  
Treatment Plant ◽  
Chloride Concentration ◽  
Chloride Ion ◽  
Pilot Project ◽  
Ion Concentration ◽  
Treated Wastewater ◽  
Groundwater Levels ◽  
The Impact

The Gaza Strip suffers from high pressure imposed on its water resources. There is a deficit of about 50 mm3 every year, which has led to a declination of groundwater level and deterioration of groundwater quality. New water resources are sought to fulfil the water deficit; among them is the artificial recharge of treated wastewater to groundwater. The impact of recharging partially treated wastewater in Gaza was tested through a pilot project implemented east of the existing wastewater treatment plant. The daily application of about 10,000 m3 of effluent to infiltration basins had an effect on the aquifer, which was monitored through the surrounding operating water wells over five years from 2000 until 2005. Although the monitored wells are operated for irrigation by farmers, impacts were clearly noticed. Groundwater levels improved and an increase in some areas of 0.6 m within three years was observed. The nitrate ion concentration also decreased in the groundwater due to nitrification processes. However, chloride ion, which indicates salinity, increased because the effluent has high chloride concentration. Boron levels increased in some areas to 0.5 mg/l, which could affect sensitive crops grown in the area.

scholarly journals Effect of Photooxidation on Nanofiltration Membrane Fouling During Wastewater Treatment from the Confectionery Industry

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 793
Author(s):  
Anna Marszałek ◽  
Ewa Puszczało
Keyword(s):  
Wastewater Treatment ◽  
Membrane Fouling ◽  
Cross Flow ◽  
Oxygen Demand ◽  
Industrial Applications ◽  
Treated Wastewater ◽  
Toc Removal ◽  
Before And After ◽  
Wastewater Quality ◽  
Uv Lamp

The research in this article aimed to present the possibilities of wastewater treatment coming from the confectionery plant in the nanofiltration (NF) process and the use of photooxidation to mitigate membrane fouling. The process was carried out initially in a dead-end flow system, where the most favorable membrane was selected. Next, the purification efficiency and blocking intensity of this membrane in the system were compared with cross flow. The next research involved the use of a photolytic oxidation process to pretreat sugar wastewater. UV radiation was emitted by a medium pressure mercury UV lamp model TQ 150 V. The effectiveness of the process was also evaluated based on the degree of pollutant load removal. The evaluation of the efficiency of a treatment process was based on the change of wastewater quality indicators before and after the membrane process. The following parameters were controlled: color, COD (chemical oxygen demand), TOC (total organic carbon), absorbance of UV254, nitrate, phosphate, ammonium, conductivity, and pH. During the course of pressure filtration, the following properties of the membrane were determined: the dependence of the volumetric flux of the permeate on the process duration, the permeability of the membrane, as well as the contact angle of the membranes. It was found that the use of UV reduced the phenomenon of fouling of nanofiltration membranes. The value of the permeate volumetric flow after the hour of running the process increased by 17%. However, no impact of UV on the efficiency of wastewater treatment was found. However, the NF process provided the required quality of treated wastewater that can be reused in industrial applications. The NF process resulted in a total decrease in absorbance, 99% TOC removal, and 98% color removal.

scholarly journals Synthesis of Petal-Like MnO2 Nanosheets on Hollow Fe3O4 Nanospheres for Heterogeneous Photocatalysis of Biotreated Papermaking Effluent

Materials ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2346
Author(s):  
Yangliu Du ◽  
Fuqiang Li ◽  
Yecan Peng ◽  
Shaowu Jia ◽  
Lei Lan ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Water Conservation ◽  
Reduction Rate ◽  
Oxygen Demand ◽  
Paper Mill ◽  
Heterogeneous Photocatalysis ◽  
Pollutant Emissions ◽  
Molar Ratio ◽  
Current Limit ◽  
Treated Effluent

Owing to the implementation of increasingly stringent water conservation policies and regulations, the pulp and paper mill industry must make increased efforts to meet the limits for pollutant emissions. The primary pretreatment and secondary biochemical treatment methods used currently generally fail to meet the country-specific environmental regulations, and the wastewater must be processed further even after being subjected to secondary biochemical treatments. In this work, we synthesized Fe3O4/MnO2 nanocomposites (FMNs) with a flower-like structure for use in the heterogeneous photocatalytic treatment of biotreated papermaking wastewater. FMNs1.25, which were formed using a KMnO4/Fe3O4 molar ratio of 1.25, could be separated readily using an external magnetic field and exhibited higher photocatalytic activity than those of the other samples as well as MnO2 and Fe3O4. The effects of various experimental parameters on the photocatalytic activity of FMNs1.25, including the initial pH of the wastewater and the catalyst dosage, were determined. The common chemical oxygen demand (CODCr) reduction rate in the case of this sample reached 56.58% within 120 min at a pH of 3, the CODCr of effluent after treatment was 52.10 mg/L. Further, even under neutral conditions, the CODCr of the treated effluent was below the current limit for discharge in China. Moreover, the nanocomposites exhibited good recyclability, and their catalytic activity did not decrease significantly even after five usage cycles. This study should serve as a platform for the fabrication of effective photocatalysts for the advanced treatment of biotreated papermaking effluent and refractory organic wastewater.

scholarly journals Degradation of high-concentration p-nitrophenol by Fenton oxidation

2020 ◽  
Vol 81 (10) ◽  
pp. 2260-2269
Author(s):  
Xiao Qing Lin ◽  
Wei Min Kong ◽  
Xiao Lin
Keyword(s):  
Degradation Rate ◽  
Removal Rate ◽  
Oxidative Degradation ◽  
Oxygen Demand ◽  
Fenton Oxidation ◽  
Utilization Efficiency ◽  
Molar Ratio ◽  
High Concentration ◽  
Initial Concentration ◽  
Toc Removal

Abstract This work aimed to degrade high-concentration p-nitrophenol (PNP) by Fenton oxidation. We studied various reaction parameters during Fenton oxidation, such as the iron dosage (as Fe2+), the initial concentration and temperature of PNP, and the dosage of hydrogen peroxide (H2O2), especially the influence of temperature on the PNP degradation rate and degree. Under the addition of the same molar ratio of H2O2/Fe2+ and H2O2 dosage according to the theoretical stoichiometry, the PNP degradation rate and the removal rate of total organic carbon (TOC) increased significantly with the increase in the initial PNP concentration. Moreover, the oxidative degradation effect was significantly affected by temperature. The increased reaction temperature not only significantly reduced the Fe2+ dosage, but also greatly promoted the removal rate of chemical oxygen demand (COD) and TOC, and improved the utilization efficiency of H2O2. For example, when the initial concentration of PNP was 4,000 mg·L−1, and the dosage of Fe2+ was 109 mg·L−1 (H2O2/Fe2+ = 200), the removal rates of COD and TOC at 85 °C reached 95% and 71% respectively. Both were higher than the 93% COD removal rate and 44% TOC removal rate when the dosage of Fe2+ was 1,092 mg·L−1 (H2O2/Fe2+ = 20) at room temperature.

Photochemical degradation of 4-chlorophenol in the aqueous phase using peroxyacetic acid (PAA)

2013 ◽  
Vol 67 (2) ◽  
pp. 440-445 ◽  
Author(s):  
Mausumi Mukhopadhyay ◽  
Dhiraj P. Daswat
Keyword(s):  
Batch Reactor ◽  
Oxygen Demand ◽  
Chloride Ion ◽  
Degradation Process ◽  
Ion Concentration ◽  
Gas Chromatography Mass Spectrometry ◽  
Uv Spectrophotometry ◽  
Photochemical Degradation ◽  
Peroxyacetic Acid ◽  
Residual Concentration

The photochemical degradation of 4-chlorophenol (4-CP) using ultraviolet irradiation (UV) of 6, 12 and 18 W with peroxyacetic acid (PAA) was studied in a batch reactor. The objective of this work was to investigate degradation and mineralization of 4-CP by PAA. The degradation efficiency increased with increasing UV input. The degradation process was also pH and initial PAA concentration dependent. The optimum conditions for the photochemical degradation of 4-CP as UV input, pH and PAA concentration was found to be 18 W, 9.5 and 3,040 ppm. The reaction efficiency decreased with increasing initial 4-CP concentrations. More than 95% mineralization of 4-CP was achieved with the UV/PAA process. The chloride ion concentration and chemical oxygen demand (COD) was evaluated. The chloride ion concentration and COD were decreased gradually with increasing UV input. Samples were analyzed by high pressure liquid chromatography (HPLC), UV spectrophotometry and gas chromatography–mass spectrometry (GC-MS) for residual concentration and identification of final degraded products.

Pilot Treatment of OCC-based Paper Mill Wastewater Using Pulsed Electrocoagulation

2007 ◽  
Vol 42 (1) ◽  
pp. 63-71 ◽  
Author(s):  
Yuan-Shing Perng ◽  
Eugene I-Chen Wang ◽  
Shih-Tsung Yu ◽  
An-Yi Chang ◽  
Chi-Yuan Shih
Keyword(s):  
Water Quality ◽  
Quality Indicators ◽  
Oxygen Demand ◽  
Paper Mill ◽  
Pilot Scale ◽  
Operating Conditions ◽  
Treated Wastewater ◽  
Water Quality Indicators ◽  
Operating Variables ◽  
Paper Mill Wastewater

Abstract There is an increasing trend towards the closure of white water recirculation loops in papermaking, often leading to need for system modification. A pilot-scale study was conducted using pulsed electrocoagulation technology to treat the wastewater of an old corrugated containerboard (OCC)-based paper mill, to evaluate its treatment performance. The operating variables were: a current density of 0 to 240 A/m2, a hydraulic retention time of 8 to 16 min and a coagulant (anionic polyacrylamide) dosage of 0 to 30 mg/L. The water quality indicators investigated were electrical conductivity, suspended solids (SS) and chemical oxygen demand (COD). The results obtained during the pilot-scale studies were favourable. Under the operating conditions without coagulant addition, the highest removals for conductivity, SS and COD were 47.7%, 99.3% and 75%, respectively. The use of coagulant remarkably enhanced the removal of both conductivity and COD. Using a coagulant dosage of 30 mg/L, the highest removal rates achieved for the three water quality indicators were 54.5%, 99.6% and 92.7%, respectively. These water quality levels are adequate to allow for the reuse of at least a part of the treated wastewater as makeup process water in papermaking.

scholarly journals Combined anaerobic-aerobic and UV/H2O2 processes for the treatment of synthetic slaughterhouse wastewater

2021 ◽  
Author(s):  
Ciro F. Lecompte
Keyword(s):  
Flow Rate ◽  
Oxygen Demand ◽  
Molar Ratio ◽  
Secondary Effluent ◽  
Slaughterhouse Wastewater ◽  
Loading Rates ◽  
Influent Concentration ◽  
Electricity Cost ◽  
Toc Removal ◽  
Single Process

The biological treatment of a synthetic slaughterhouse wastewater (SSWW) was studied using an anaerobic baffled reactor (ABR) and an aerobic activated sludge (AS) at a laboratory scale, with total organic carbon (TOC) loading rates of 0.03–1.01 g/(L.day), total nitrogen (TN) loading rates of 0.01–0.19 g/(L.day), and a flow rate of 2.93 to 11.70 mL/min in continuous mode. Results revealed that combined anaerobic-aerobic processes had higher efficiency to treat SSWW than a single process. Up to 96.36% TOC, 80.53% TN, and 99.38% 5-day carbonaceous biochemical oxygen demand (CBOD5) removal from an influent concentration of 1,008.85 mgTOC/L, 419.77 mgTN/L, and 640 mgCBOD5/L at the hydraulic retention time (HRT) of 6.24 days and a flow rate of 3.75 mL/min was achieved. The UV/H2O2 process was studied to treat a secondary effluent of SSWW with TOC loadings of 64.88–349.84 mg/L. Up to 75.22% TOC and 84.38% CBOD5 removal were obtained for an influent concentration of 64.88 mgTOC/L at the HRT of 3 h with H2O2 concentration of 900 mg/L. An optimum molar ratio dosage of 13.87 mgH2O2/mgTOCin was also obtained. Combined anaerobic-aerobic and UV/H2O2 processes enhanced the biodegradability of the TOC, TN, and CBOD5 present in the SSWW. Up to 99.98% TOC, 82.84% TN, and 99.69% CBOD5 overall removals were obtained for an influent concentration of 1,004.88 mgTOC/L, 200.03 mgTN/L, and 640 mgCBOD5/L at the HRT of 4 days and a flow rate of 5.90 mL/min. A cost-effectiveness analysis (CEA) was performed for the optimum conditions for the SSWW treatment by optimizing total electricity cost and HRT, in which the combined anaerobic-aerobic and UV/H2O2 processes had an optimal TOC removal of 92.46% at an HRT of 41 h, a cost of $1.25/kg of TOC removed, and $11.60/m3 of treated SSWW. This process reaches a maximum TOC removal of 99% in 76.5 h with an estimated cost of $2.19/kg TOC removed and $21.65/m3 treated SSWW.

scholarly journals Combined anaerobic-aerobic and UV/H2O2 processes for the treatment of synthetic slaughterhouse wastewater

2021 ◽  
Author(s):  
Ciro F. Lecompte
Keyword(s):  
Flow Rate ◽  
Oxygen Demand ◽  
Molar Ratio ◽  
Secondary Effluent ◽  
Slaughterhouse Wastewater ◽  
Loading Rates ◽  
Influent Concentration ◽  
Electricity Cost ◽  
Toc Removal ◽  
Single Process

The biological treatment of a synthetic slaughterhouse wastewater (SSWW) was studied using an anaerobic baffled reactor (ABR) and an aerobic activated sludge (AS) at a laboratory scale, with total organic carbon (TOC) loading rates of 0.03–1.01 g/(L.day), total nitrogen (TN) loading rates of 0.01–0.19 g/(L.day), and a flow rate of 2.93 to 11.70 mL/min in continuous mode. Results revealed that combined anaerobic-aerobic processes had higher efficiency to treat SSWW than a single process. Up to 96.36% TOC, 80.53% TN, and 99.38% 5-day carbonaceous biochemical oxygen demand (CBOD5) removal from an influent concentration of 1,008.85 mgTOC/L, 419.77 mgTN/L, and 640 mgCBOD5/L at the hydraulic retention time (HRT) of 6.24 days and a flow rate of 3.75 mL/min was achieved. The UV/H2O2 process was studied to treat a secondary effluent of SSWW with TOC loadings of 64.88–349.84 mg/L. Up to 75.22% TOC and 84.38% CBOD5 removal were obtained for an influent concentration of 64.88 mgTOC/L at the HRT of 3 h with H2O2 concentration of 900 mg/L. An optimum molar ratio dosage of 13.87 mgH2O2/mgTOCin was also obtained. Combined anaerobic-aerobic and UV/H2O2 processes enhanced the biodegradability of the TOC, TN, and CBOD5 present in the SSWW. Up to 99.98% TOC, 82.84% TN, and 99.69% CBOD5 overall removals were obtained for an influent concentration of 1,004.88 mgTOC/L, 200.03 mgTN/L, and 640 mgCBOD5/L at the HRT of 4 days and a flow rate of 5.90 mL/min. A cost-effectiveness analysis (CEA) was performed for the optimum conditions for the SSWW treatment by optimizing total electricity cost and HRT, in which the combined anaerobic-aerobic and UV/H2O2 processes had an optimal TOC removal of 92.46% at an HRT of 41 h, a cost of $1.25/kg of TOC removed, and $11.60/m3 of treated SSWW. This process reaches a maximum TOC removal of 99% in 76.5 h with an estimated cost of $2.19/kg TOC removed and $21.65/m3 treated SSWW.

scholarly journals The research on the control of chlorinated by-products by the combined process of three-dimensional electrode system and ultraviolet-photocatalytic oxidation

2021 ◽  
Author(s):  
Li Wang ◽  
Hong Liang ◽  
Kaibin Zhang ◽  
Hong Huang ◽  
Qingchun Wang
Keyword(s):  
Photocatalytic Oxidation ◽  
Degradation Mechanism ◽  
Three Dimensional ◽  
Oxygen Demand ◽  
Advanced Oxidation ◽  
Chloride Ion ◽  
Ion Concentration ◽  
Dominant Factor ◽  
Treatment Technology ◽  
By Products

Abstract Advanced oxidation technology is considered to be the most potential wastewater treatment technology. As one of the advanced oxidation technologies, three-dimensional electrochemical system (3DES) is often used to treat industrial wastewater that is difficult to degrade. Sulphonated phenolic resin (SMP) was treated as a characteristic pollutant in sulfonated drilling wastewater. The separate effect of current, the dosage of particle electrodes, chloride ion concentration and initial pH on chlorinated by-products were analyzed by the response surface methodology (RSM). Results showed that the current is the most dominant factor, followed by the dosage of particle electrodes. The ultraviolet-electrolysis (UVEL) system was implemented by adding ultraviolet light under the optimal electrolysis (EL) system. The chemical oxygen demand (CODcr) and total organic carbon (TOC) removal rates of the UVEL system were respectively increased by 19% and 29.39% compared with the EL system, the concentration of chlorinated by-products was also reduced by 534.4 mg/L when the UV irradiance was 5.24 mW/cm2. These results indicated that the UVEL system degrades SMP more thoroughly. The enhanced reaction mechanism of UVEL system and the possible degradation pathway for SMP were proposed via controlling free radical quenching experiments and the product of EL and UVEL processes. The results showed that the high degradation efficiency of the UVEL system can be attributed to the synergistic degradation mechanism present in the UVEL system, where the photolysis of active chlorine species (ACl) promotes the increase of hydroxyl radical (·OH).

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