This study investigated the efficacy of using micro-flocculation as a pretreatment approach in alleviating ultrafiltration (UF) membrane fouling caused by organic matter in treated wastewater. Three typical model dissolved organic matters (DOM), humic acid, fulvic acid, and sodium alginate, were employed to simulate membrane fouling. The results showed that micro-flocculation using poly aluminum chloride (PAC) or polymerized ferric sulfate (PFS) as flocculant could effectively enhance the treatment performance of the UF process on DOM. With 6 mg/L PAC, the removal efficiency of humic acid, fulvic acid, and sodium alginate by micro-flocculation combined UF process reached 79.95%, 63.25%, and 51.14%, respectively. Specifically, after micro-flocculation, micromolecular hydrophilic organic matter (e.g., fulvic acid) tended to form a compact cake layer. The macromolecular hydrophobic organic matter (e.g., humic acid) and macromolecular hydrophilic organic matter (e.g., sodium alginate) generally led to a loose cake layer. At PAC dosage of 6 mg/L, the membrane specific flux (J/J0) at the end was improved by 11.71%, 10.27%, and 2.2% for humic acid, sodium alginate and fulvic acid solutions, respectively, compared with the UF process alone. It could be inferred that micro-flocculation pretreatment can effectively mitigate the membrane fouling when treating wastewater containing humic acid, sodium alginate, or fulvic acid.
{"title":"Effects of micro-flocculation pretreatment on the ultrafiltration membrane fouling caused by different dissolved organic matters in treated wastewater","authors":"Lan-Yang Ren, Chen Liu, Ting Meng, Yingxue Sun","doi":"10.2166/wrd.2021.051","DOIUrl":"https://doi.org/10.2166/wrd.2021.051","url":null,"abstract":"\u0000 This study investigated the efficacy of using micro-flocculation as a pretreatment approach in alleviating ultrafiltration (UF) membrane fouling caused by organic matter in treated wastewater. Three typical model dissolved organic matters (DOM), humic acid, fulvic acid, and sodium alginate, were employed to simulate membrane fouling. The results showed that micro-flocculation using poly aluminum chloride (PAC) or polymerized ferric sulfate (PFS) as flocculant could effectively enhance the treatment performance of the UF process on DOM. With 6 mg/L PAC, the removal efficiency of humic acid, fulvic acid, and sodium alginate by micro-flocculation combined UF process reached 79.95%, 63.25%, and 51.14%, respectively. Specifically, after micro-flocculation, micromolecular hydrophilic organic matter (e.g., fulvic acid) tended to form a compact cake layer. The macromolecular hydrophobic organic matter (e.g., humic acid) and macromolecular hydrophilic organic matter (e.g., sodium alginate) generally led to a loose cake layer. At PAC dosage of 6 mg/L, the membrane specific flux (J/J0) at the end was improved by 11.71%, 10.27%, and 2.2% for humic acid, sodium alginate and fulvic acid solutions, respectively, compared with the UF process alone. It could be inferred that micro-flocculation pretreatment can effectively mitigate the membrane fouling when treating wastewater containing humic acid, sodium alginate, or fulvic acid.","PeriodicalId":17556,"journal":{"name":"Journal of Water Reuse and Desalination","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2021-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48699672","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The purpose of this work was to evaluate the efficiency of oil sorption of silica particles modified by three different types of cationic polymers and a cationic surfactant. Low-molecular-weight polyethyleneimine (LPEI), high-molecular-weight polyethyleneimine (HPEI), polydiallyldimethylammonium chloride (PDM), and cetyltrimethylammonium bromide (CTAB) were used to modify the silica particles and then compared their performances for oil removal. The scanning electron microscope and zeta potential measurements were used to analyze the surface characteristics of unmodified and modified silica particles. Adsorptions of motor oil and palm oil on the modified silica particles have been investigated under various parameters such as the silica particle size, the oil concentration, the polymer/surfactant concentrations, and the pH. The results have shown that the modified silica particles enhanced the oil sorption ability by approximately 10–20 times depending on the size of silica particles, pH, and the type of polymer/surfactant used when compared with the unmodified silica particles. The highest palm oil adsorption values of LPEI-silica, HPEI-silica, PDM-silica, CTAB-silica, and unmodified silica were 2.40, 2.10, 1.95, 1.50, and 0.15 g/gsilica, respectively. Moreover, the oil sorption of the modified silica particles was increased by approximately 30–50% for the smallest-sized silica particles.
{"title":"Removing free-floating oil from water using cationic polymers/surfactant-modified silica","authors":"Anucha Ruksanti, Sorapong Janhom","doi":"10.2166/wrd.2021.065","DOIUrl":"https://doi.org/10.2166/wrd.2021.065","url":null,"abstract":"\u0000 The purpose of this work was to evaluate the efficiency of oil sorption of silica particles modified by three different types of cationic polymers and a cationic surfactant. Low-molecular-weight polyethyleneimine (LPEI), high-molecular-weight polyethyleneimine (HPEI), polydiallyldimethylammonium chloride (PDM), and cetyltrimethylammonium bromide (CTAB) were used to modify the silica particles and then compared their performances for oil removal. The scanning electron microscope and zeta potential measurements were used to analyze the surface characteristics of unmodified and modified silica particles. Adsorptions of motor oil and palm oil on the modified silica particles have been investigated under various parameters such as the silica particle size, the oil concentration, the polymer/surfactant concentrations, and the pH. The results have shown that the modified silica particles enhanced the oil sorption ability by approximately 10–20 times depending on the size of silica particles, pH, and the type of polymer/surfactant used when compared with the unmodified silica particles. The highest palm oil adsorption values of LPEI-silica, HPEI-silica, PDM-silica, CTAB-silica, and unmodified silica were 2.40, 2.10, 1.95, 1.50, and 0.15 g/gsilica, respectively. Moreover, the oil sorption of the modified silica particles was increased by approximately 30–50% for the smallest-sized silica particles.","PeriodicalId":17556,"journal":{"name":"Journal of Water Reuse and Desalination","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2021-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42088215","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the present photoelectrochemical (PEC) system utilizing MoS2 nanoflakes as a wide spectrum absorptive photoanode, simultaneous PEC degradation of different organic pollutants was achieved by employing in situ generated oxysulfur radicals, superoxide and hydroxyl radicals as strong oxidants. In order to better understand the cooperative PEC degradation of representative organic pollutants including rhodamine B dye (RhB), chlorpyrifos (CPF) and ciprofloxacin (CIP), the influences by bias potential, solution pH, radical scavenger, dissolved oxygen concentration and electrolyte concentration have been investigated. The selective PEC degradation efficiency follows the order of CPF > RhB > CIP in mixed substrates condition. In addition, the degradation rate for the single substrate degradation was about two times higher compared to that in mixed substrates degradation. The experimental results verified that reactive oxidation species (ROS) including oxysulfur radicals, superoxide and hydroxyl radicals can be efficiently produced on both anode and cathode under visible light irradiation, and they work together for simultaneous degradation of different pollutants, but the contribution of each ROS for pollutant degradation is substrate dependent. These results indicate that cooperative oxidation of multiple pollutants by miscellaneous oxygen-based radicals should be further considered as a promising advanced oxidation technique.
{"title":"Photoelectrocatalytic generation of miscellaneous oxygen-based radicals towards cooperative degradation of multiple organic pollutants in water","authors":"Yurou Zhou, Guan Zhang, Jing Zou","doi":"10.2166/wrd.2021.018","DOIUrl":"https://doi.org/10.2166/wrd.2021.018","url":null,"abstract":"\u0000 In the present photoelectrochemical (PEC) system utilizing MoS2 nanoflakes as a wide spectrum absorptive photoanode, simultaneous PEC degradation of different organic pollutants was achieved by employing in situ generated oxysulfur radicals, superoxide and hydroxyl radicals as strong oxidants. In order to better understand the cooperative PEC degradation of representative organic pollutants including rhodamine B dye (RhB), chlorpyrifos (CPF) and ciprofloxacin (CIP), the influences by bias potential, solution pH, radical scavenger, dissolved oxygen concentration and electrolyte concentration have been investigated. The selective PEC degradation efficiency follows the order of CPF > RhB > CIP in mixed substrates condition. In addition, the degradation rate for the single substrate degradation was about two times higher compared to that in mixed substrates degradation. The experimental results verified that reactive oxidation species (ROS) including oxysulfur radicals, superoxide and hydroxyl radicals can be efficiently produced on both anode and cathode under visible light irradiation, and they work together for simultaneous degradation of different pollutants, but the contribution of each ROS for pollutant degradation is substrate dependent. These results indicate that cooperative oxidation of multiple pollutants by miscellaneous oxygen-based radicals should be further considered as a promising advanced oxidation technique.","PeriodicalId":17556,"journal":{"name":"Journal of Water Reuse and Desalination","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2021-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48056906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
L. Bing, L. Youle, Chen Chuan, Xu Jianliang, Lian Huashan, Ma Zhun
It is still one of the significant solutions to treat saline wastewater with thermal desalination technology, especially falling film evaporators. To improve the performance of the falling film evaporator, a numerical study on the gas–liquid two-phase flow characteristics of saline wastewater in the vertical pipe was conducted using the VOF model. The results showed that the inlet velocity of the saline wastewater increased under the same operating conditions, resulting in the thickening of the liquid film and the increase of the average convective heat transfer coefficient. Increasing the inlet temperature of the working liquid reduced the temperature difference, which led to a decrease of the average convective heat transfer coefficient. In addition, as the inlet concentration of the working liquid increased, the film flow rate and the average convective heat transfer coefficient first decreased and then increased slightly. The experimental results verified the accuracy of the numerical simulation, and the average error was 9.27%.
{"title":"Distribution of heat transfer coefficient in the vertical tube of falling film evaporator treating saline wastewater based on micro flow and experimental verification","authors":"L. Bing, L. Youle, Chen Chuan, Xu Jianliang, Lian Huashan, Ma Zhun","doi":"10.2166/wrd.2021.014","DOIUrl":"https://doi.org/10.2166/wrd.2021.014","url":null,"abstract":"\u0000 It is still one of the significant solutions to treat saline wastewater with thermal desalination technology, especially falling film evaporators. To improve the performance of the falling film evaporator, a numerical study on the gas–liquid two-phase flow characteristics of saline wastewater in the vertical pipe was conducted using the VOF model. The results showed that the inlet velocity of the saline wastewater increased under the same operating conditions, resulting in the thickening of the liquid film and the increase of the average convective heat transfer coefficient. Increasing the inlet temperature of the working liquid reduced the temperature difference, which led to a decrease of the average convective heat transfer coefficient. In addition, as the inlet concentration of the working liquid increased, the film flow rate and the average convective heat transfer coefficient first decreased and then increased slightly. The experimental results verified the accuracy of the numerical simulation, and the average error was 9.27%.","PeriodicalId":17556,"journal":{"name":"Journal of Water Reuse and Desalination","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2021-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48921392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Inci Boztepe, Stephen R. Gray, Jianhua Zhang, Jun-de Li
HFP-co-PVDF/N6 hydrophobic/hydrophilic dual-layer membrane was used to study desalination with direct contact membrane distillation (DCMD). A one-dimensional (1-D) model was proposed to predict the flux and thermal efficiency. Heat and mass transfer equations were solved numerically for the combined hydrophilic and hydrophobic layers. The membrane characteristics of the hydrophobic layer were considered for the calculation of the mass transfer coefficients, while the hydrophilic layer was ignored since it was assumed to be filled with water. However, the hydrophilic layer was taken into account during the calculations of conductive heat transfer. Therefore, the equations are different, compared to single-layer hydrophobic membranes. It was found that with the same hydrophobic membrane characteristics, the single-layer membranes performed with better flux and thermal efficiency than the dual-layer membranes. Furthermore, the improvement of flux and thermal efficiency by an addition of the hydrophilic layer has not been observed experimentally, and it is suggested that the improved performance for dual-layer membranes reported previously is due to improved permeability by using thinner and more porous hydrophobic layers that can be mechanically reinforced by the hydrophilic layer. The validation of the model was conducted by comparing the experimental results for single- and dual-layer membranes with the modelling results. The predicted flux and thermal efficiency by the modelling were within 10% error to the experimental results.
{"title":"Performance modelling of direct contact membrane distillation using a hydrophobic/hydrophilic dual-layer membrane","authors":"Inci Boztepe, Stephen R. Gray, Jianhua Zhang, Jun-de Li","doi":"10.2166/wrd.2021.072","DOIUrl":"https://doi.org/10.2166/wrd.2021.072","url":null,"abstract":"\u0000 HFP-co-PVDF/N6 hydrophobic/hydrophilic dual-layer membrane was used to study desalination with direct contact membrane distillation (DCMD). A one-dimensional (1-D) model was proposed to predict the flux and thermal efficiency. Heat and mass transfer equations were solved numerically for the combined hydrophilic and hydrophobic layers. The membrane characteristics of the hydrophobic layer were considered for the calculation of the mass transfer coefficients, while the hydrophilic layer was ignored since it was assumed to be filled with water. However, the hydrophilic layer was taken into account during the calculations of conductive heat transfer. Therefore, the equations are different, compared to single-layer hydrophobic membranes. It was found that with the same hydrophobic membrane characteristics, the single-layer membranes performed with better flux and thermal efficiency than the dual-layer membranes. Furthermore, the improvement of flux and thermal efficiency by an addition of the hydrophilic layer has not been observed experimentally, and it is suggested that the improved performance for dual-layer membranes reported previously is due to improved permeability by using thinner and more porous hydrophobic layers that can be mechanically reinforced by the hydrophilic layer. The validation of the model was conducted by comparing the experimental results for single- and dual-layer membranes with the modelling results. The predicted flux and thermal efficiency by the modelling were within 10% error to the experimental results.","PeriodicalId":17556,"journal":{"name":"Journal of Water Reuse and Desalination","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2021-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46876278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In our previous study, it was noticed that the combined freezing, soaking and centrifugal desalination (FSCD) process is unsuitable to be applied in summer, because very little pure ice can be produced when the temperature of raw seawater used as soaking liquid reaches 27 °C. Therefore, two main efforts on the process optimization were made in this paper. One is that low-temperature seawater was served as soaking liquid in all the experiments. In real industrial practice, the low-temperature soaking liquid can be obtained through melting pure ice products or recovering cold energy from cold concentrated brine. The effects of centrifugal parameters and soaking time on salt removal efficiency and ice yield rate were investigated. Second, the gravity-induced method was combined to form freezing, soaking, gravity-induced and centrifugal desalination (FSGCD) process for further improvement of the salt removal efficiency. The influence of melting time of gravity-induced process was studied by keeping the samples ambient with an air temperature of 30 °C. Finally, the performance among different processes was compared. Results showed that the salt removal efficiency of FSGCD process can reach up to 97.03%. The study is effectively helpful to improve the process performance of soaking treatment in summer application.
{"title":"Application of low temperature soaking liquid in combined freezing-based desalination processes in summer","authors":"Hui Yang, Yuan-guang Jiang, Mengxiao Fu, Rui Wang","doi":"10.2166/WRD.2021.122","DOIUrl":"https://doi.org/10.2166/WRD.2021.122","url":null,"abstract":"\u0000 In our previous study, it was noticed that the combined freezing, soaking and centrifugal desalination (FSCD) process is unsuitable to be applied in summer, because very little pure ice can be produced when the temperature of raw seawater used as soaking liquid reaches 27 °C. Therefore, two main efforts on the process optimization were made in this paper. One is that low-temperature seawater was served as soaking liquid in all the experiments. In real industrial practice, the low-temperature soaking liquid can be obtained through melting pure ice products or recovering cold energy from cold concentrated brine. The effects of centrifugal parameters and soaking time on salt removal efficiency and ice yield rate were investigated. Second, the gravity-induced method was combined to form freezing, soaking, gravity-induced and centrifugal desalination (FSGCD) process for further improvement of the salt removal efficiency. The influence of melting time of gravity-induced process was studied by keeping the samples ambient with an air temperature of 30 °C. Finally, the performance among different processes was compared. Results showed that the salt removal efficiency of FSGCD process can reach up to 97.03%. The study is effectively helpful to improve the process performance of soaking treatment in summer application.","PeriodicalId":17556,"journal":{"name":"Journal of Water Reuse and Desalination","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2021-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49021642","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Fe-Mn oxides composite prepared by a chemical co-precipitation method was used as a heterogenous peroxydisulfate catalyst for the decomposition of aniline. This study investigated the mechanism of aniline degradation by PDS activated with catalyst. Reactive species resulting in the degradation of aniline was investigated via radical quenching experiments with different scavengers, including methanol, tert-butyl alcohol, EDTA and sodium azide. Based on the experiments made here, it is speculated that the predominant reactive species responsible for the degradation of aniline may be holes and singlet molecular oxygen rather than SO4·− and ·OH radicals. The degradation of compounds in catalyst/peroxydisulfate system was put forward. The three possible intermediates were speculated by high performance liquid chromatography-mass spectrometry, and two possible degradation pathways were proposed.
{"title":"The removal efficiencies and mechanism of aniline degradation by peroxydisulfate activated with magnetic Fe-Mn oxides composite","authors":"L. Qiao, Yu Shi, Q. Cheng, B. Liu, Jing Liu","doi":"10.2166/WRD.2021.102","DOIUrl":"https://doi.org/10.2166/WRD.2021.102","url":null,"abstract":"\u0000 The Fe-Mn oxides composite prepared by a chemical co-precipitation method was used as a heterogenous peroxydisulfate catalyst for the decomposition of aniline. This study investigated the mechanism of aniline degradation by PDS activated with catalyst. Reactive species resulting in the degradation of aniline was investigated via radical quenching experiments with different scavengers, including methanol, tert-butyl alcohol, EDTA and sodium azide. Based on the experiments made here, it is speculated that the predominant reactive species responsible for the degradation of aniline may be holes and singlet molecular oxygen rather than SO4·− and ·OH radicals. The degradation of compounds in catalyst/peroxydisulfate system was put forward. The three possible intermediates were speculated by high performance liquid chromatography-mass spectrometry, and two possible degradation pathways were proposed.","PeriodicalId":17556,"journal":{"name":"Journal of Water Reuse and Desalination","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48524246","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
P. Jin, Yingshu Sun, Can Wang, Huang Huang, Yin Wu
{"title":"Cutting-edge technology and systems for water treatment and reuse","authors":"P. Jin, Yingshu Sun, Can Wang, Huang Huang, Yin Wu","doi":"10.2166/WRD.2021.001","DOIUrl":"https://doi.org/10.2166/WRD.2021.001","url":null,"abstract":"","PeriodicalId":17556,"journal":{"name":"Journal of Water Reuse and Desalination","volume":"11 1","pages":"147-148"},"PeriodicalIF":2.3,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43484328","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The existence of nitrate and dissolved organic matter (DOM) in water can react with chlorine disinfectant to form chloronitromethane (CNM) with high toxicity. The purpose of this study was to investigate the effects of NH4NO3, NaNO3 and Ca(NO3)2 on the formation of CNM under UV/chlorine treatment when glucose was used as the carbon source. The results showed that the formation of CNM from nitrate and glucose was raised first and then decreased. Among three types of nitrate, the potential of forming CNM from NH4NO3 was the largest. The concentration of CNM increased with increasing glucose concentration and UV intensity, while it decreased with increasing pH from 6 to 8. The analysis of various nitrogen showed that NH3-N and were converted into dissolved organic nitrogen (DON) under UV/chlorine treatment. The formation pathways of CNM from nitrate and glucose had been inferred under UV/chlorine treatment. Actual water samples were used to verify the laws found in the laboratory. The study could provide the development of a new disinfection method for water treatment and be useful for controlling the generation of CNM under UV/chlorine treatment.
{"title":"Effects of nitrate and glucose on the formation of chloronitromethane (CNM) under UV/chlorine treatment","authors":"D. Lin, Xu Bohui, Zhu Fanfang, S. Prasad","doi":"10.2166/WRD.2021.010","DOIUrl":"https://doi.org/10.2166/WRD.2021.010","url":null,"abstract":"\u0000 The existence of nitrate and dissolved organic matter (DOM) in water can react with chlorine disinfectant to form chloronitromethane (CNM) with high toxicity. The purpose of this study was to investigate the effects of NH4NO3, NaNO3 and Ca(NO3)2 on the formation of CNM under UV/chlorine treatment when glucose was used as the carbon source. The results showed that the formation of CNM from nitrate and glucose was raised first and then decreased. Among three types of nitrate, the potential of forming CNM from NH4NO3 was the largest. The concentration of CNM increased with increasing glucose concentration and UV intensity, while it decreased with increasing pH from 6 to 8. The analysis of various nitrogen showed that NH3-N and were converted into dissolved organic nitrogen (DON) under UV/chlorine treatment. The formation pathways of CNM from nitrate and glucose had been inferred under UV/chlorine treatment. Actual water samples were used to verify the laws found in the laboratory. The study could provide the development of a new disinfection method for water treatment and be useful for controlling the generation of CNM under UV/chlorine treatment.","PeriodicalId":17556,"journal":{"name":"Journal of Water Reuse and Desalination","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2021-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44532921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In recent years, with the advocacy of the circular economy and the rising awareness of environmental protection, energy saving, water saving and carbon reduction have become important topics for discussion today. The high-tech semiconductor, photoelectric, solar and other electronic industries involve high energy and water consumption. In addition to responding to the energy saving, water saving and carbon reduction, one of the main purposes of this system development is to reduce the use of materials and make the process chemicals reusable. In the practical factory operation, a large amount of water is used in the polarization process, and the wastewater generated in etching and pickling is discharged continuously. In order to recycle the water discharging from the manufacturing process, the reverse osmosis membrane system (RO membrane system) is often used for wastewater recycling. In this study, the KI waste liquid discharging from the process of a polarizing plate factory was concentrated with anti-fouling RO membrane. The quantity and arrangement of RO system membranes were simulated and designed with software, and the results, such as water volumes and pressures of inflow and outflow water for the membrane, changes of membrane pressure difference (ΔP), changes of permeating water quality, chemical cleaning frequency and water collection time, were discussed and the optimal parameters of RO membrane, such as the best water collection volume and time, chemical cleaning frequency, best concentration, time and temperature matching with cleaning in process (CIP) were inferred so as to improve the stability of the RO membrane system, enable RO permeating water to enter the water purifying system for reuse, reduce the treatment cost of wastewater recycle and improve the permeating water output efficiency of treatment equipment, accommodating effective utilization of water resources and economic benefits and to sustainable development of the industry.
近年来，随着循环经济的倡导和环保意识的提高，节能、节水、减碳已成为当今讨论的重要话题。高科技的半导体、光电、太阳能和其他电子行业涉及高能耗和高用水量。除了响应节能、节水、减碳的需求外，本系统开发的主要目的之一是减少材料的使用，使工艺化学品可重复使用。在工厂实际运行中，极化过程要使用大量的水，蚀刻和酸洗过程中产生的废水是连续排放的。为了回收制造过程中排放的水，通常采用反渗透膜系统(RO膜系统)进行废水回收。本研究采用反渗透膜对某偏光板厂生产过程中排放的KI废液进行浓缩处理。利用软件对反渗透系统膜的数量和布置进行了模拟和设计，讨论了反渗透系统膜的入出水水量和压力、膜压差变化(ΔP)、渗透水质变化、化学清洗频率和集水时间等结果，并确定了反渗透膜的最佳集水量和时间、化学清洗频率、最佳浓度、为提高RO膜系统的稳定性，使RO渗透水能够进入净水系统回用，降低废水回用的处理成本，提高处理设备的渗透水输出效率，实现水资源的有效利用和经济效益，促进行业的可持续发展，推断出与CIP (cleaning in process)匹配的时间和温度。
{"title":"Evaluation of the benefit of practically operating reverse osmosis system in the factory: taking the recycling of KI solution and water of the screen polarizing plate as an example","authors":"S. Tseng, C. Lo, C. Hung","doi":"10.2166/WRD.2021.110","DOIUrl":"https://doi.org/10.2166/WRD.2021.110","url":null,"abstract":"\u0000 In recent years, with the advocacy of the circular economy and the rising awareness of environmental protection, energy saving, water saving and carbon reduction have become important topics for discussion today. The high-tech semiconductor, photoelectric, solar and other electronic industries involve high energy and water consumption. In addition to responding to the energy saving, water saving and carbon reduction, one of the main purposes of this system development is to reduce the use of materials and make the process chemicals reusable. In the practical factory operation, a large amount of water is used in the polarization process, and the wastewater generated in etching and pickling is discharged continuously. In order to recycle the water discharging from the manufacturing process, the reverse osmosis membrane system (RO membrane system) is often used for wastewater recycling. In this study, the KI waste liquid discharging from the process of a polarizing plate factory was concentrated with anti-fouling RO membrane. The quantity and arrangement of RO system membranes were simulated and designed with software, and the results, such as water volumes and pressures of inflow and outflow water for the membrane, changes of membrane pressure difference (ΔP), changes of permeating water quality, chemical cleaning frequency and water collection time, were discussed and the optimal parameters of RO membrane, such as the best water collection volume and time, chemical cleaning frequency, best concentration, time and temperature matching with cleaning in process (CIP) were inferred so as to improve the stability of the RO membrane system, enable RO permeating water to enter the water purifying system for reuse, reduce the treatment cost of wastewater recycle and improve the permeating water output efficiency of treatment equipment, accommodating effective utilization of water resources and economic benefits and to sustainable development of the industry.","PeriodicalId":17556,"journal":{"name":"Journal of Water Reuse and Desalination","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2021-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43227009","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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