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Performance study and kinetic modeling of hybrid bioreactor for treatment of bi-substrate mixture of phenol-m-cresol in wastewater:Process optimization with response surface methodology

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Journal of Environmental Sciences 2013年第4期25卷 698-709页

作者： Sudipta Dey Somnath mukherjee Department of Biotechnology Heritage Institute of TechnologyAnandapurChowbaga RoadKolkata-700107West BengalIndia Environmental Engineering Division Civil Engineering DepartmentJadavpur UniversityRaja S.C.Mallic RoadKolkata-700032West BengalIndia

Performance of a hybrid reactor comprising of trickling filter （TF） and aeration tank （AT） unit was studied for biological treatment of wastewater containing mixture of phenol and m-cresol, using mixed microbial culture. The reactor was operated with hydraulic loading rates （HLR） and phenolics loading rates （PLR） between 0.222-1.078 m3/（m2-day） and 0.900-3.456 kg/（***）, respectively. The efficiency of substrate removal varied between 71%-100% for the range of HLR and PLR studied. The fixed film unit showed better substrate removal efficiency than the aeration tank and was more resistant to substrate inhibition. The kinetic parameters related to both units of the reactor were evaluated and their variation with HLR and PLR were monitored. It revealed the presence of substrate inhibition at high PLR both in TF and AT unit. The biofilm model established the substrate concentration profile within the film by solving differential equation of substrate mass transfer using boundary problem solver tool ＇bvp4c＇ of mATLAB 7. 1 software. Response surface methodology was used to design and optimize the biodegradation process using Design Expert 8 software, where phenol and m-cresol concentrations, residence time were chosen as input variables and percentage of removal was the response. The design of experiment showed that a quadratic model could be fitted best for the present experimental study. Significant interaction of the residence time with the substrate concentrations was observed. The optimized condition for operating the reactor as predicted by the model was 230 mg/L of phenol, 190 mg/L of m-cresol with residence time of 24.82 hr to achieve 99.92% substrate removal.

关键词： hybrid bioreactor bi-substrate phenol m-cresol response surface methodology biofilm model

Separation of m-cresol from aromatic hydrocarbon and alkane using ionic liquids via hydrogen bond interaction

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Chinese Journal of Chemical Engineering 2019年第11期27卷 2675-2686页

作者： Qian Liu Xianglan Zhang Wei Li School of Chemical and Environmental Engineering China University of Mining and TechnologyBeijing 100083China School of Chemical Engineering Beijing Institute of Petro-Chemical TechnologyBeijing 102600China

Low temperature coal tar contained a large amount of phenols, aromatic hydrocarbons and alkanes;the separation of phenols from coal tar has a great significance to the deep processing of coal tar. In this work, the separation of m-cresol from cumene and n-heptane by liquid–liquid extraction using ionic liquids(ILs) as extractants was studied. The suitable ILs were screened by conductor-like screening model for real solvents(COSmO-RS)model and the liquid–liquid phase equilibrium(LLE) experiments were to verify the accuracy of the screening results. The extraction conditions such as extraction time, extraction temperature and mass ratio of ILs to model oils were evaluated. An internal mechanism of the m-cresol extract by ILs was revealed by COSmO-RS calculation and FT-IR. The results showed that the selected ILs can extract m-cresol effectively from cumene and nheptane, 1-ethyl-3-methylimidazolium acetate(emim CH3 COO) was the best extraction solvent. A hydrogen bond between anion of ILs and phenolic hydroxyl groups was observed. m-cresol in model oils could be extracted with extraction efficiencies up to 98.85% at an emim CH3 COO: model oils mass ratio of 0.5 and 298.15 K,emim CH3 COO could be regenerated and reused for 4 cycles without obvious decreases in extraction efficiency and extractant mass.

关键词： Extraction m-cresol Ionic liquids Separation COSmO-RS Hydrogen bond

Kinetics of phenol and m-cresol biodegradation by an indigenous mixed microbial culture isolated from a sewage treatment plant

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Journal of Environmental Sciences 2008年第12期20卷 1508-1513页

作者： Pichiah Saravanan Kannan Pakshirajan Prabirkumar Saha Department of Chemical Engineering Indian Institute of Technology GuwahatiGuwahati Department of Biotechnology Indian Institute of Technology GuwahatiGuwahati

An acclimatized mixed microbial culture,predominantly Pseudomonas sp.,was enriched from a sewage treatment plant,and its potential to simultaneously degrade mixtures of phenol and m-cresol was investigated during its growth in batch shake flasks.A 22 full factorial design with the two substrates at two different levels and different initial concentration ranges(low and high),was employed to carry out the biodegradation *** substrates phenol and m-cresol were completely utilized within 21 h when ...

关键词： biodegradation factorial design of experiments kinetics m-cresol mixed microbial culture phenol sum kinetics model

A highly hydrothermal stable copper-based catalyst for catalytic wet air oxidation of m-cresol in coal chemical wastewater

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Chinese Journal of Chemical Engineering 2023年第5期57卷 338-348页

作者： Bingxiao Feng Lining Hao Chaoting Deng Jiaqiang Wang Hongbing Song meng Xiao Tingting Huang Quanhong Zhu Hengjun Gai College of Chemical Engineering Qingdao University of Science and TechnologyQingdao 266042China

Catalytic wet air oxidation(CWAO) can degrade some refractory pollutants at a low cost to improve the biodegradability of wastewater. However, in the presence of high temperature and high pressure and strong oxidizing free radicals, the stability of catalysts is often insufficient, which has become a bottleneck in the application of CWAO. In this paper, a copper-based catalyst with excellent hydrothermal stability was designed and prepared. TiO_(2) with excellent stability was used as the carrier to ensure the longterm anchoring of copper and reduce the leaching of the catalyst. The one pot sol–gel method was used to ensure the super dispersion and uniform distribution of copper nanoparticles on the carrier, so as to ensure that more active centers could be retained in a longer period. Experiments show that the catalyst prepared by this method has good stability and catalytic activity, and the catalytic effect is not significantly reduced after 10 cycles of use. The oxidation degradation experiment of m-cresol with the strongest biological toxicity and the most difficult to degrade in coal chemical wastewater was carried out with this catalyst. The results showed that under the conditions of 140℃, 2 mPa and 2 h, m-cresol with a concentration of up to 1000 mg·L^(-1) could be completely degraded, and the COD removal rate could reach 79.15%. The biological toxicity of wastewater was significantly reduced. The development of the catalyst system has greatly improved the feasibility of CWAO in the treatment of refractory wastewater such as coal chemical wastewater.

关键词： Hydrothermal stability Ultra-dispersed copper-based catalyst Catalytic wet air oxidation m-cresol Biological toxicity

Comparison of Photochemical Reactions of m-cresol in Aqueous Solution and in Ice

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Chemical Research in Chinese Universities 2012年第1期28卷 47-52页

作者： PENG Fei1, XUE Hong-hai1, TANG Xiao-jian1,2, KANG Chun-li1, LI Lin-lin1 and LI Zhe1 1. Key Laboratory of Groundwater Resources and Environment, ministry of Education, Jilin University, Changchun 130021, P. R. China 2. School of municipal and Environmental Engineering, Jilin Institute of Architecture and Civil Engineering, Changchun 130118, P. R. China Jilin Univ Key Lab Groundwater Resources & Environm Minist Educ Changchun 130021 Peoples R China Jilin Inst Architecture & Civil Engn Sch Municipal & Environm Engn Changchun 130118 Peoples R China

We compared the photochemical reaction of m-cresol containing ·OH precursors such as H2O2, NO2 and NO3 in aqueous solution with those in ice. The results show that the conversion rate of m-cresol in aqueous solution was higher than that in ice. H2O2, NO2 and NO3 all accelerated the photoconversion of m-cresol in both aqueous solution and ice. The photochemical reactions of m-cresol obeys the first order kinetics equation. According to the photoproducts identified by GC-mS, we proposed that hydroxylation and nitration reactions occurred in both aqueous solution and ice. Coupling reaction was common in ice, however, in aqueous solution it was found only in UV system. Our results suggest that the photochemical reactions of m-cresol were different in aqueous solution and in ice.

关键词： m-cresol Photochemistry Aqueous solution Ice mechanism