CHEMOSPHERE
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2019
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IF 5.108
Liheng Liu,Dongwei He,Fei Pan,Rong Huang,Hua Lin,Xuehong Zhang
In this study, Fe/Cu, Fe/Al/Cu, Fe/Cu/C and Fe/Al/Cu/C internal electrolysis systems (IESs) were constructed and used to treat methylene blue dye (MB) wastewater. The effects of filler mass ratio, filler dosage, solution pH, reaction time and reaction temperature on COD removal were discussed, while the kinetics, thermodynamics and mechanism of COD removal were also investigated. The results showed that when the COD removal rates were basically the same, the reaction times of Fe/Al/Cu, Fe/Cu/C and Fe/Al/Cu/C IESs were shorter, and the filler dosages were lower. For the four systems, the appropriate pH was around 5, while the suitable reaction temperature was in the range of 20–25 °C. The COD removals of these four IESs were generally greater than 90%. The COD removal processes of the four systems could be better described by the improved pseudo-second-kinetic model, and the liquid film diffusion was the rate-controlling step. Moreover, the COD removal was a spontaneous and endothermic process. MB was degraded into inorganic substances in four steps. In addition, the FTIR characterization of the fillers before and after reaction suggests the four IESs have good stability.
研究领域:
环境科学
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化学工程
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产品关联
DOI
PubMed
高影响因子
Desalination and Water Treatment
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2015
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IF 1.173
Chong Lin,Jianbo Liao,Chaohai Wei
The coagulation process by ferrous sulfate was used to pretreat coking wastewater prior to a subsequent biological treatment. The central composite Box–Behnken experimental design and response surface method were applied to evaluate and optimize the interactive effects of three operating variables, namely the initial pH, dosage of ferrous sulfate, and interaction time, on the physical and chemical performances of coagulation. Four dependent parameters, namely COD removal, cyanide removal, sulfide removal, and total oil removal, were either directly measured or calculated as responses. According to analysis of variances results, the four models proposed in this work can be used to navigate the design space, with the high regression coefficient R2 varying from 0.9158 to 0.9877. The initial pH, ferrous sulfate dosage, and interaction time had significant effects on the COD removal, cyanide removal, sulfide removal, and total oil removal due to their respective effects on chemical precipitation and coagulation removal. The synergies effect of chemical precipitation and coagulation during ferrous sulfate coagulation process controlled the treatment. A visual search of the overlaying critical response contours plot was carried out, and the results indicated the optimum conditions to an initial pH 11, ferrous sulfate dosage of 1.5 g/L, and reaction time of 120 min. The experimental date and models’ predictions agreed well. COD removal, cyanide removal, sulfide removal, and total oil removal of 15.25, 93.82, 73.36, and 4.73%, respectively, were demonstrated. The results of a B/C analysis and cost evaluation show that FeSO4 coagulation is an appropriate technology for coking wastewater pretreatment.
研究领域:
环境工程
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化学工程
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DOI
高影响因子
Journal of Water Process Engineering
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2022
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IF 7.34
Zhonghua Wang,Hui Qiao,Zhongchen Yu,Xue Yang,Ziyu Tang,Wei Zhou,Haiqian Zhao
The H 2 O 2 , O 2 − , OH, and HO 2 generated by the anode and cathode are considered the possible sources of the oxidizing power of the electro-Fenton system. For improving the current efficiency, the assessment of the degradability of anode and various active substances to pollutants is an important prerequisite. The COD removal ratio was used as a judgment index for the first time, and the effect of various active substances produced by the electro-Fenton anode and cathode on the removal of COD in benzene-containing wastewater was analyzed. The results revealed that the contribution rate of the active substances produced by the cathode for the COD removal is 63.21%. Among the active substances, the contribution rate of OH, which is the most important active substance, is 58.86%. The contribution rate of the anode is 36.79%. The COD removal ratio of the system is considered the best when I = 200 mA, pH = 3, and [FeSO 4 ] 0 = 60 mg/L, which is estimated as 72.59%. The contribution rate of OH, which is produced by the cathode, to the removal of COD is positively correlated with the total COD removal ratio. These findings are of great significance. That is only by improving the utilization rate of OH and reducing the ineffective consumption of OH, the removal of COD can be promoted, and the bottleneck problem of low electro-Fenton current efficiency can be solved.
研究领域:
环境科学
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化学工程
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2024
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IF 13.3
Mushi Li,Xi Wang,Mingyu Ma,Juan Wu,Yang Chen,Jinbao Ou,Xinyue Chen,Qianying Zhou,Wenjing Sang,Shihong Xu,Li Cai,Dengxin Li
This study focused on the treatment of high-concentration pharmaceutical wastewater with high-salinity by pretreatment of chemical synthesis coupling with evaporation. Via chemical synthesis, this pretreatment process was developed to remove the organic matter that inhibited evaporation of wastewater, resulting in improved evaporation efficiency. Lab-scale results demonstrated that under the optimum conditions (∼pH 9, 2 mL/L demulsifier, 98 mM/L H 2 O 2 , 3 h of aeration time, 80 °C, 500 mg/L PAC, and 20 mg/L PAM), 54.9 % of COD was successfully removed by single pretreatment and 98.6 % after coupling with evaporation. Compared to the 80.1 % COD removal efficiency of direct evaporation of 100 mL with 30 min, the pretreatment process coupling with evaporation demonstrated superior performance and halved the evaporation time. A pilot-scale chemical synthesis pretreatment (120 t/d) was further developed to treat pharmaceutical wastewater of both high COD concentrations and high salinity. Under the optimal conditions determined in the lab-scale experiments, the pilot-scale achieved a COD removal efficiency of 49 % with a single pretreatment and 95.8 % after coupling with mechanical vapor recompression (MVR). Additionally, the obtained salt appeared visually clean and white compared to that obtained from the treated wastewater without pretreatment. Furthermore, to elucidate the possible mechanisms driving the efficient removal of COD, GC–MS was performed on the wastewater before and after pretreatment, and the resulting products from pretreatment in pilot-scale applications were further determined by both FTIR and GC–MS. It was proposed that the aldol condensation reaction increased the formation of carbon chains to macromolecular compounds might be the possible mechanism. This study gives insights into the future application of low-investment and low-cost technology in the treatment of high-concentration pharmaceutical wastewater with high salinity in industry.
研究领域:
环境工程
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化工技术
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废水处理
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DOI
高影响因子
Journal of Materials Research and Technology-JMR&T
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2024
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IF 6.2
Yonglian Qiao,Lingxu Yang,Erwei Xie,Mengqi Luo,Le Wang,Chaoliu Zeng,Huijun Liu
Titanium alloy chemical milling wastewater contains a significant amount of ethylene glycol monobutyl ether (EGBE), which is toxic and difficult to be degraded by microorganisms, and the emission will lead to severe environmental pollution. To solve this problem, the electrocatalytic oxidation method was employed to remove EGBE in the wastewater, in which a porous Ti 4 O 7 /Ti electrode were prepared and employed as the anode, while stainless steel acted as the cathode. The effects of current density, interelectrode distance, and stirring mode on the COD removal rate were also investigated. Results show that the COD of the wastewater significantly decreases from 12410 to 15 mg L −1 after 16 h of electrolysis at 10 mA cm −2 and electrode spacing of 1.0 cm as well as aeration stirring at 100 mL min −1 . Moreover, pilot-plant scale testing reveals that the COD decreasing from 11980 to 183 mg L −1 after 24 h of electrolysis. Consequently, the utilization of porous Ti 4 O 7 /Ti electrode as anode in the electrocatalytic oxidation method presents significant potential in removal of EGBE in aviation industry wastewater.
研究领域:
环境科学
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电化学工程
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工业废水处理
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产品关联
DOI
高影响因子
Desalination and Water Treatment
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2024
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IF 1
Zhanmeng Liu,Xian Li,Lichun Xu,Rongrong Liu
ABSTRACT A novel composite coagulant of MFPAC was prepared from Fe 3 O 4 nanoparticles and polyaluminum chloride (PAC). Landfill leachate was pretreated by MFPAC coagulation combined with mineralized refuse adsorption. Higher COD and color removals were achieved by using the MFPAC magnetic coagulant than by adding the coagulant PAC alone. Under the working conditions of 1:3 Fe 3 O 4 /PAC mass ratios, 1.5 g/L MFPAC dosage, and pH 7.5, the removal rates of COD and color reached 63% and 67%, respectively. Infrared spectra showed that MFPAC is a type of hydroxyl-containing ligand with a nano-Fe 3 O 4 multi-core and a hydroxyl polymer of aluminum and iron that is similar complex valence and crystal structure as that of PAC. The effluent of MFPAC coagulation was further treated using mineralized refuse adsorption. Under the working conditions of <2 mm particle size of mineralized refuse, 700°C roasting temperature, 40 mg/L adsorbent dosage, and pH 9.0, the removal rates of COD and ammonia nitrogen reached up to 57% and 68%, respectively, after 12 h of treatment. Infrared spectra analysis revealed that OH, C=O, and C–O played key roles in the adsorption process. After the landfill leachate was treated with the combined process, the removal rates of COD, color, and ammonia nitrogen were enhanced to 84%, 80%, and 74%, respectively. The encouraging results demonstrated that the combined process could provide a viable alternative to the pretreatment of landfill leachate.
研究领域:
环境工程
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废水处理
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2015
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IF 2.752
Shuchen Tu,Fengzhu Lv,Pan Hu,Zilin Meng,Hongtao Ran,Yihe Zhang
Secondary and primary amines containing silica foams (F–SiO 2 ) were prepared by using silane coupling agents, (3-aminopropyl) triethoxysilane (KH-550) and bis(3-triethoxysilicyl propyl)-amine (KH-270), as modifiers. Not only Brunauer–Emmett–Tell (BET) surface and pore size of F–SiO 2 are greatly reduced after modification, but also increased chemical oxygen demand (COD) removal efficiency to trinitrotoluene (TNT) red water is obtained. Among the series of F–SiO 2 , the secondary amine modified silica foams possess higher COD removal capacity. Controlled experiments indicate the adsorption mainly derives from the attraction of amine groups toward the negative organic pollutants in TNT red water rather than the effect of the large BET surface and hydroxyl groups on the surface of F–SiO 2 . The adsorption model studies show the pseudo-second-order dynamic adsorption model and Langmuir isotherm model well fit the experimental data. The prepared amine-modified F–SiO 2 is an efficient adsorbents of organic pollutants in TNT red water.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
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2024
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IF 5.5
Xiaoyan He,Shuo Ma,Zhilan Wang,Zheping Tan,Miaomiao Hou,Penggai Ma,Runze Cao,Xiaoquan Lu
Microbial fuel cell (MFC) can generate electrons through microbial metabolism of organic matter in sewage. In this paper, carbon felt as base material, the conductive polymers polyaniline and polypyrrole combined with silver nanowires were doped in hydrogel, a super hydrophilicity, low electron transfer resistance, good biocompatibility hydrogel MFC anode (PANI-PPy-Ag NWs/CF) were prepared. It showed a hand-torn bread structure, this three-dimensional (3D) porous structure increased microbial attachment amount. The anode could reach a maximum voltage output of 0.66 V in only 5.5 h, and produce a maximum power density of 2196.61 mW/m 3 . Due to the doping of silver nanowire, a new electronic mode was explored, coulomb efficiency of 31.01 % and an ultra-high COD removal rate (96.69 %) was obtained. This study introduces a conductive composite hydrogel MFC anode, which provides a new idea for the material diversity, electrical production and sewage removal performance of MFC anode.
研究领域:
环境科学
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材料科学
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微生物学
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产品关联
DOI
高影响因子
International Journal of Electrochemical Science
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2023
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IF 1.5
Qizhou Dai,Lei Jiang,Xubiao Luo
Titanium based lead dioxide electrodes were successfully prepared by the method of electrodeposition in nitrate solution, including titanium base, Sn-SbO X interlayer, α-PbO 2 middle layer and β-PbO 2 active layer. Rhodamine B (RhB) was selected as the model pollutant to optimize the effects of operational factors in the electrochemical oxidation process. The removal of RhB and chemical oxygen demand (COD) were detected at different reaction time and the relative optimized results were achieved on condition of the concentration of supporting electrolyte, initial RhB concentration, pH value and applied current density at 0.1 mol/L, 200 mg/L, 4.4, and 20 mA/cm 2 , respectively. The kinetics results on RhB removal indicated that RhB degradation by electrochemical oxidation followed the pseudo- first-order reaction. Besides, UV-vis spectra revealed that the conjugated structure of RhB was easier and prior to be degraded. The intermediates generated in the solution were identified by GC/MS and a possible degradation pathway of RhB was proposed.
研究领域:
环境科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2023
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IF 5.2
Junhao Fu,Zhifeng Zhang,Guanshuo Han,Haisheng Han,Ruohua Liu,Liqiang Zeng,Jianhua Kang,Tong Yue
Starch wastewater poses significant environmental harm, necessitating the implementation of effective treatment methods. The current starch wastewater treatment methods have some drawbacks, such as limited application scenarios, complicated process and insufficient purification efficiency. This study focuses on the purification of starch wastewater through metallic-starch complexes (MSCs) and magnetic flocculation . Metal ions (Fe 3+ , Pb 2+ and Al 3+ ) were added to interact with starch and coagulate, forming MSCs, in which the O 6 atom of the branched chain methanol most likely to interact with metal ions. Then, the magnetic particles, sintering dust (SD), was utilized to adsorb the MSCs and form magnetic flocs, facilitating their rapid settlement under an external magnetic field. The purification experiments were aimed at a high-concentration starch wastewater with COD concentration of 12,000 mg/L, and the results demonstrated the metal ions could effectively coordinate with starch and form MSCs, achieving a COD removal rate of over 90%. Meanwhile, to address the challenge of difficult settlement of MSCs, the addition of SD induced the magnetic flocculation with MSCs through Van der Waals force and electrostatic force , which effectively reduced settling time and decreased sedimentation layer thickness. The combined use of MSCs and magnetic flocculation achieved efficient purification of starch wastewater.
研究领域:
环境科学
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污水处理
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ENVIRONMENTAL MANAGEMENT
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2021
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IF 6.789
Siying Sun,Jiabao Ren,Jiale Liu,Liang Rong,Hangli Wang,Yeyuan Xiao,Faqian Sun,Rongwei Mei,Chongjun Chen,Xiaomei Su
The feasibility of pyrite as catalysts in the persulfate oxidation and electron donor for subsequent bacterial denitrification was investigated. The results demonstrated that pyrite-activated persulfate oxidation could efficiently degrade the organic matter in the effluent of biological landfill leachate treatment system, and COD removal efficiency of about 45% was achieved at the optimum parameters: pH = 6, pyrite dosage = 9.28 mM, dimensionless oxidant dose = 0.25. Among the dissolved organic matter , hydrophobic dissolved organic carbon (HO DOC), humic acids and building blocks were the main components. After the pyrite-activated persulfate oxidation, humic acids and HO DOC were primarily degraded, followed by building blocks, while low molecular weight neutrals were probably the degradation products . In the subsequent biological process, nitrate reduction was satisfactorily accomplished with autotrophic denitrification as the main pathway. When the influent nitrate concentration was about 180 mg L −1 , the effluent nitrate concentration was stable below 20 mg L −1 with the nitrogen removal rate of about 108 mg L −1 d −1 . To sum up, the pyrite-activated persulfate oxidation and the following biological denitrification was a feasible application in the effluent of biological landfill leachate treatment system.
研究领域:
环境科学
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微生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
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2024
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IF 7.4
Ning Liu,Xin Zhao,Can Wang,Yanchao Li,Shuang Pan,Weiqi Huang,Israel Hakizimana,Wei Kong,Yan Wang
In the coal chemical industry, the concentrated waters produced by nanofiltration and reverse osmosis are usually evaporated and crystallized. During the evaporation crystallization process, high COD levels can lead to problems such as the entrainment of liquid droplets and excessive amounts of mother liquor. Therefore, there is an urgent need to develop efficient, stable, and engineering-applicable organic matter degradation technologies before the evaporation crystallization process. In this study, Ti-ENTA/SnO 2 -Sb and GF-5 were combined as cathodes to form an electrochemical flow-through oxidation system to treat nanofiltration concentrate (NFCs) and reverse osmosis concentrate (ROCs). The experimental results show that within the current density range of 10–20 mA·cm −2 , the chemical oxygen demand (COD) removal rates of NFCs and ROCs are 55.3 %–85.2 % and 49.9 %–93.6 %, respectively. And the oxidation system can be used stably for a long time, fully meeting the practical application needs. In addition, this article further analyzed the effects of current density, initial organic matter concentration, pH value, and electrode spacing on COD removal. The results indicate that the COD removal efficiency is mainly affected by current density and initial organic matter concentration. Finally, a comprehensive comparison was made on the efficiency and cost of various advanced oxidation technologies in treating wastewater. The results indicate that the electrochemical flow-through oxidation system has significant cost advantages. The cost of processing NFCs and ROCs per cubic meter is $0.96 and $1.23, respectively. These findings indicate that the electrochemical flow-through oxidation system proposed is an advanced oxidation technology with economic benefits and practical application prospects.
研究领域:
环境工程
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）