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Photocatalytic Oxidation for Determination of chemical oxygen demand Using Nano-TiO2 Film

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Chinese Journal of Chemistry 2005年第10期23卷 1425-1429页

作者：丁红春柴怡浩张中海刘梅川鲜跃仲潘振声金利通 Department of Chemistry East China Normal University Shanghai 200062 China

A photocatalytic oxidation method for determination of chemical oxygen demand （COD） using nano-TiO2 film, based on the use of a nano-TiO2-Ce（SO4）2 system and electrochemical detection, was proposed. The technique was originated from the direct determination of the Ce（Ⅲ） concentration change resulting from photocatalytic oxidation of organic compounds. Ce（Ⅲ）, which was produced by photocatalytic reduction of Ce（SO4）2, could be measured at a multi-walled carbon nanotubes （MWNT） chemically modified electrode （CME）. The COD values by this method were calculated from the differential pulse voltammetry （DPV） current of Ce（Ⅲ） at the CME. Under the optimal operation conditions, the detection limit of 0.5 mg·L^-1 COD with the linear range of 1-600 mg·L^-1 was achieved. This method was also applied to determination of various COD of ground water and wastewater samples. The resuits were in good agreement with those from the conventional COD methods, i.e., permanganate and dichromate ones.

关键词： photocatalytic oxidation chemical oxygen demand electrochemical detection nano-TiO2 film

Study on Determination of chemical oxygen demand in Water with Ion Chromatography

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Chinese Journal of Chemistry 2007年第2期25卷 228-232页

作者：张中海丁红春方艳菊鲜跃仲金利通 Department of Chemistry East China Normal University Shanghai 200062 China

A new method for determining chemical oxygen demand （COD） value in water using ion chromatography coupled with nano TiO2-K2S2O8 co-existing system was described. The photocatalytic oxidation system and nano TiO2-K2S2O8 co-existing system could degrade the organic compounds in water. All sulfur-containing species in the reactive solution were eventually transformed to sulfate which could be determined by conductivity detector in ion chromatography. The change of conductivity of sulfate was proportional to COD value. The optimal experimental conditions and the mechanism of the detection were discussed. The application range was 10.0-300.0 mg·L^-1 and the lowest limit of detection was 3.5 mg·L^-1. It was considered that the value obtained could be reliably correlated with the COD value obtained using the conventional methods.

关键词： ion chromatography chemical oxygen demand nano TiO2-K2S2O8

Rapid microwave determination of chemical oxygen demand of aromatic-based tar-wash wastewaters from biomass gasification

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Rapid microwave determination of chemical oxygen demand of a...

Water quality prediction of copper-molybdenum miningbeneficiation wastewater based on the PSO-SVR model

2018中国环境科学学会科学技术年会

作者： Mei-juan Xu Chang-xing Hu Min-yan Qin Fu-yan Gao Wei Li Yue-li Hao Warren A.Dick Ningbo Institute of Technology Zhejiang University College of Environmental Sciences and Engineering Nankai University School of Environment and Natural Resources The Ohio State University

A rapid microwave method was developed to measure COD in aromatic-based tar-wash wastewaters from biomass *** were microwave digested for only 32 min at 720 W or 18 min at 1200 W in an acidic K Cr O-Ag SO-HgSO solution,followed by spectrophotometric quantification of unreacted reactant Cr at 455 nm from 50 to 200 mg L COD or of generated product Cr at 599 nm from 200 to 1000 mg L *** with the theoretical COD obtained by GC-MS analysis,the microwave COD value was slightly lower for the cornstraw gasification-derived wastewater sample containing 6.3%hard-to-digest COD,mainly due to *** microwave COD value was even lower for the sawdust gasification-derived wastewater sample containing 28%hard-to-digest COD mainly due to toluene and ***,the microwave digestion method-yielded similar COD values as the standard two-hour open reflux for both *** interference was not observed even though both samples contained significant amounts of NH and *** of the high COD raw wastewater sample into the above measurable ranges did not bias the *** coefficients of variation of triplicate samples’ COD values were below 5%.Therefore,the microwave method was rapid,applicable for high COD samples,free of ammonium interference,precise,and as accurate as the standard open reflux method.

关键词： chemical oxygen demand dichromate open reflux digestion microwave digestion biomass gasification tar-wash wastewater

来源： cnki会议评论

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环境科学与工程前沿(英文) 2023年第8期17卷 81-94页

作者： Xiaohua Fu Qingxing Zheng Guomin Jiang Kallol Roy Lei Huang Chang Liu Kun Li Honglei Chen Xinyu Song Jianyu Chen Zhenxing Wang Ecological Environment Management and Assessment Center Central South University of Forestry and TechnologyChangsha 410004China State Environmental Protection Key Laboratory of Water Environmental Simulation and Pollution Control South China Institute of Environmental SciencesMinistry of Ecology and EnvironmentGuangzhou 510655China Chinese Non-Ferrous Industrial Engineering Center of Pollution Control Technology&Equipment Science Environment Protection Co.Ltd.Changsha 410036China Institute of Computer Science University of TartuTartu 51009Estonia School of Environmental Science and Engineering Guangzhou UniversityGuangzhou 510006China A.B Freeman School of Business Tulane UniversityNew OrleansLA 70118USA Guangzhou Huacai Environmental Protection Technology Co. Ltd.Guangzhou 511480China

The mining-beneficiation wastewater treatment is highly complex and *** factors like influent quality,flow rate,pH and chemical dose,tend to restrict the effluent effectiveness of miningbeneficiation wastewater *** oxygen demand(COD)is a crucial indicator to measure the quality of mining-beneficiation *** COD concentration accurately of miningbeneficiation wastewater after treatment is essential for achieving stable and compliant *** reduces environmental risk and significantly improves the discharge quality of *** paper presents a novel AI algorithm PSO-SVR,to predict water *** optimization of our proposed model PSO-SVR,uses particle swarm optimization to improve support vector regression for COD *** generalization capacity tested on out-of-distribution(OOD)data for our PSOSVR model is strong,with the following performance metrics of root means square error(RMSE)is 1.51,mean absolute error(MAE)is 1.26,and the coefficient of determination(R2)is *** compare the performance of PSO-SVR model with back propagation neural network(BPNN)and radial basis function neural network(RBFNN)and shows it edges over in terms of the performance metrics of RMSE,MAE and R2,and is the best model for COD prediction of mining-beneficiation *** is because of the less overfitting tendency of PSO-SVR compared with neural network *** proposed PSO-SVR model is optimum for the prediction of COD in copper-molybdenum mining-beneficiation wastewater *** addition,PSO-SVR can be used to predict COD on a wide variety of wastewater through the process of transfer learning.

关键词： chemical oxygen demand Mining-beneficiation wastewater treatment Particle swarm optimization Support vector regression Artificial neural network

Recyclable Joule heated low shrinkage carbon nanofiber aerogels for microscale oil/water separation

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Journal of Materials Science & Technology 2022年第32期127卷 89-97页

作者： Guangkai Hu Dong Liu Sidi Yin Bin Yu Tao Huang Hao Yu Meifang Zhu State Key Laboratory for Modification of chemical Fibers&Polymer Materials College of Materials Science&EngineeringDonghua UniversityShanghai 201620China

Aerogels have shown great potential as oil adsorbents but their application to the removal of microscale oil from water and their recycling remains *** present work proposed a freeze-shaping method for fabricating carbon nanofiber aerogels(CNFAs)based on the direct use of one-dimensional(1D)carbon nanofibers(CNF)rather than carbonization of polymer *** technique greatly reduces volume shrinkage and increases the three-dimensional(3D)structural stability of the *** nanotubes(CNT)and gelatinized starch were incorporated in these aerogels as a conductive enhancement agent and binder,respectively,forming a“vine(CNT)-wrapped tree(CNF)”structure that improved mechanical and Joule-heating *** effects of glutaraldehyde added to aerogels as a crosslinking agent on mechanical properties and microstructure were also systematically *** optimized CNFAs combined with low density,high porosity,good elasticity,and superior Joule-heating efficiency along with suitable adsorption capacity,excellent selectivity,and cycling *** material was able to selectively remove 87%and 92%of microscale acetone and dimethylformamide(DMF),respectively,from the water after nine cycles of adsorption and *** present work demonstrates a novel means of designing and fabricating a low shrinkage CNFA with outstanding Joule-heating performance having potential practical applications in the remediation of organic pollution.

关键词： Electrospinning Carbon nanofiber aerogel Volume shrinkage Joule-heating chemical oxygen demand

The Ability of Some Aquatic and Terrestrial Plants to Purify Domestic Wastewater

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Phyton-International Journal of Experimental Botany 2023年第8期92卷 2245-2260页

作者： Abida Kausar Noreen Zahra Humaira Kiran Sadia Asim Abid Raza Ali Raza Department of Botany Government College Women UniversityFaisalabad38000Pakistan Department of Botany University of AgricultureFaisalabad38040Pakistan Department of Chemistry Government College Women UniversityFaisalabad38000Pakistan Department of Agronomy Muhammad Nawaz Shareef University of AgricultureMultan66000Pakistan College of Agriculture Fujian Agriculture and Forestry UniversityFuzhou350002China

The study aimed to evaluate the ability of some terrestrial and aquatic plants for wastewater puriﬁ*** plants can remove pollutants from wastewater by consuming and accumulating various contaminants in different parts of *** aquatic and terrestrial plants(Rosa sinensis,Typha latifolia,Ocimm bacilicum,Azolla pinnata,and Salvinia molesta)which have the ability to decrease water pollution were utilized in this *** capability offive different species of plants was investigated by measuring chemical oxygen demand(COD),biological oxygen demand(BOD),electrical conductivity(EC),total dissolved solids(TDS),and pH of the *** this research,some aquatic and terrestrial plants were transplanted in wastewater plastic pots containing domestic wastewater with different ratios of 50%and 100%.Then,after 30 days,the physiological and biochemical parameters of plants were calculated to observe the effect of wastewater on *** revealed higher chlorophyll and carotenoids in typha plants treated with 100%*** highest percentage of elimination in BOD(65%),COD(27%),TDS(72%),EC(83%),and pH(6.8%)was noted with the use of typha and ***,total soluble sugars,total free amino acids,and total proteins were found maximum in the hibiscus plant as compared to the other plants under 100%and 50%domestic wastewater treatment,while typha and ocimum showed lower values of these parameters irrespective of wastewater ***,the COD,BOD,TDS,EC,and pH trend was higher in 100%wastewater as compared to 50%*** into account the accumulation capacity of the tested plants especially typha can be efﬁciently used for the treatment of domestic wastewater.

关键词： Biological oxygen demand chemical oxygen demand domestic wastewater aquatic plants terrestrial plants

EFFICIENT CONTAMINANT REMOVAL FROM LIQUID DIGESTATE OF PIG MANURE BY chemical PRECIPITATION AND CO_(2) MINERALIZATION USING ALKALINE ASH

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Frontiers of Agricultural Science and Engineering 2023年第3期10卷 479-491页

作者： Zhengxin FEI Zijie DING Xuan ZHENG Liang FENG Qingyao HE Shuiping YAN Long JI College of Pharmaceutics Jinhua PolytechnicJinhua 321007China Technology&Equipment Center for Carbon Neutrality in Agriculture College of EngineeringHuazhong Agricultural UniversityWuhan 430070China

chemical precipitation is a widely applied approach for a liquid fraction of digestate(LFD)of agricultural waste but its large-scale application requires low-cost and efficient precipitating agents and novel process *** study evaluated novel approach for the efficient removal of contaminants from the LFD using fly ash-based chemical precipitation,followed by filtration and CO_(2) *** technical feasibility of this approach was evaluated using pH and electrical conductivity(EC),and removal efficiencies of total phosphorus(TP),chemical oxygen demand(COD)and heavy metals during the *** fly ash used in this study showed a promising performance as a chemical precipitation agent for COD and TP removal from the treated LFD involving complex effects of precipitation and ***_(2) bubbling after fly ash-based chemical precipitation provided further COD and TP removal by carbonation reactions between CO_(2) and the excessive alkaline minerals in fly *** addition of fly ash to untreated LFD increased pH from 8.3 to 12.9 and EC from 7.01 to 13.7 mS·cm^(−1),CO_(2) bubbling helped neutralize the treated LFD and reduce the EC,and concentrations of toxic ions by carbonation *** fly ash-based chemical precipitation and CO_(2) mineralization had>93%COD and>98%TP removal efficiencies,and resulted in an EC of<2 mS·cm^(−1) and a neutral pH in the treated LFD,as well as the high purity calcite product.

关键词： anaerobic digestion chemical oxygen demand fly ash ion removal total phosphate

Application of a novel backwashing process in upflow biological aerated filter

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Journal of Environmental Sciences 2010年第3期22卷 362-366页

作者： Jinshui Yang Weijie Liu Baozhen Li Hongli Yuana Meiping Tong Jinsong Gao State Key Laboratory for A grobiotechnology College of Biological Sciences Key Laboratory of Agro-Microbial Resource and Application Ministry of Agriculture China Agricultural University Beijing 100193 China. The key Laboratory of Water and Sediment Sciences Ministry of Education Department of Environmental Engineering Peking University Beijing 100871 China Changsha Medical College Changsha 410219 China

To improve the efficiency of backwashing in upflow biological aerated filter （BAF）, a novel backwashing process named air-water siphon backwashing （AWSB） was proposed and applied on laboratory scale. The effects of backwashing on turbidity and suspended solid （SS） in backwashing efluent using this new backwashing process were compared with those of traditional backwashing process, namely air-water backwashing （AWB）. In AWB, the turbidity of backwashing efluent maintained 100 NUT when consumed 60 min and 10.5 L water. However, in AWSB, it declined to 44 NUT, consumed 40 min, and 7 L water. The COD removal of BAF after backwashing was also analyzed. The average removal rate of COD in the reactor backwashed by AWB and AWSB was 89.34% and 90.91%, respectively. Compared with AWB, the backwashing interval had been prolonged 35%. The volume of backwashing water in that AWSB was only 66.7% of that in AWB. The results demonstrated that AWSB required less water and took shorter backwashing timerelative to AWB to achieve the same turbidity of backwashing efluent, and AWSB was more effective in removing fouling than that of AWB. More significant advantage of AWSB was that the backwashing interval was effectively prolonged

关键词： biological aerated filter air-water siphon backwashing chemical oxygen demand

Flocculation behaviors of a novel papermaking sludge-based flocculant in practical printing and dyeing wastewater treatment

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Frontiers of Environmental Science & Engineering 2021年第5期15卷 283-293页

作者： Kangying Guo Baoyu Gao Jie Wang Jingwen Pan Qinyan Yue Xing Xu Shandong Key Laboratory of Water Pollution Control and Resource Reuse School of Environmental Science and EngineeringShandong UniversityQingdao266237China

In our previous studies,several papermaking sludge-based flocculants(PSBFs)were synthesized from wood pulp papermaking *** structure-activity relationships of the PSBFs have been investigated in simulated dye wastewater treatment,but their efficiencies in practical printing and dyeing wastewater(PPDW)treatment are ***,an PSBF was prepared,and its performance is discussed in comparison to polyaluminium chloride(PAC)and polyacrylamide(PAM)in PPDW *** PSBF was used in three ways:as an independent flocculant,as a PAC aid,or used to treat the effluent of the PAC *** results indicated that adding PSBF alone produced similar color and chemical oxygen demand(COD_(Cr))removals as the PAC system alone,but PSBF performed better than PAC when the pH of PPDW was higher than *** PSBF as a PAC aid improved the color,COD_(Cr)and turbidity removals,but the elimination efficiencies were slightly lower than those of the PAC+PAM ***,when PSBF was used as a flocculant to treat the effluent of the PAC system(PAC→PSBF),the effluent qualities were *** with the PAC system,the color and COD_(Cr)removals of PAC→PSBF system increased by 16.21%and 13.26%,*** excitation and emission matrix fluorescence results indicated that PSBF removed tryptophan-like pollutants more efficiently than *** the pH requirements of the subsequent bioreactor treatment in practice,the PAC→PSBF system were also investigated at the PPDW pH level of *** maximum removal efficiencies of color,COD_(Cr)and turbidity were 90.17%,32.60%and 82.50%,respectively.

关键词： Practical wastewater treatment Commercial coagulant/flocculant Secondary coagulation-flocculation process chemical oxygen demand Coagulation-flocculation mechanism