检索结果-南通市图书馆

Enhanced adsorption of phosphate by loading nanosized ferric oxyhydroxide on anion resin

在线全文

学校读者我要写书评

暂无评论

Frontiers of Environmental Science & Engineering 2014年第4期8卷 531-538页

作者： Jing ren Nan LI Lin ZHAO nanqi ren School of Environmental Science and Engineering Tianjin University Tianjin 300072 China State Key Laboratory of Urban Water Resource and Environment Harbin Institute of Technology Harbin 150090 China

Ferric oxyhydroxide loaded anion exchanger （FOAE） hybrid adsorbent was prepared by loading nanosized ferric oxyhydroxide （FO） on anion exchanger resin for the removal of phosphate from wastewater. TEM and XRD analysis confirmed the existence of FO on FOAE. After FO loading, the adsorption capacity of the hybrid adsorbent increased from 38.70 to 51.52mg.g-1. Adsorption processes for both FOAE and anion resin were better fit to the pseudo first order model. Batch adsorption experiments revealed that higher temperature （313K）, higher initial phosphate concentration （50 mg.L-1） and lower solution pH （pH value of 2） would be more propitious to phosphate adsorption. Competition effect of coexisting anions on phosphate removal can be concluded as sulfate 〉 nitrate 〉 chloride. Freundlich isotherm model can describe the adsorption of phosphate on FOAE more accurately, which indicated the heterogeneous adsorption occurred on the inner-surface of FOAE.

关键词： phosphate removal adsorption nanosized ferric oxyhydroxide anion exchanger

Preparation and characterization of a lipoid adsorption material and its atrazine removal performance

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2011年第8期23卷 1293-1298页

作者： Zhiqiang Chen Qinxue Wen Jiaxiang Lian nanqi ren State Key Laboratory of Urban Water Resource and Environment Harbin Institute of Technology Harbin 150090 China. National Engineering Research Center of Urban Water Resources Harbin Institute of Technology Harbin 150090 China

A novel adsorbent named lipold adsorption material （LAM）, with a hydrophoblc nucleolus （trlolem） and a hydrophlllc membrane structure （polyamide）, was synthesized to remove hydrophobic organic chemicals （HOCs） from solution. Triolein, a type of lipoid, was entrapped by the polyamide membrane through an interfacial polymerization reaction. The method of preparation and the structure of the LAM were investigated and subsequent experiments were conducted to determine the characteristics of atrazine （a type of HOC） removal from wastewater using LAM as the adsorbent. The results showed that LAM had a regular structure compared with the prepolymer, where compact particles were linked with each other and openings were present in the structure of the LAM in which the fat drops formed from triolein were entrapped. In contrast to the atrazine adsorption behavior of powdered activated carbon （PAC）, LAM showed a persistent adsorption capacity for atrazine when initial concentrations of 0.57, 1.12, 8.31 and 19.01 mg/L were present, and the equilibrium time was 12 hr. Using an 8 mg/L initial concentration of atrazine as an indicator of HOCs in aqueous solution, experiments on the adsorption capacity of the LAM showed 69.3% removal within 6-12 hr contact time, which was close to the 75.5% removal of atrazine by PAC. Results indicated that LAM has two atrazine removal mechanisms, namely the bioaccumulation of atrazine by the nucleous material and physical adsorption to the LAM membrane. Bioaccumulation was the main removal mechanism.

关键词： lipoid adsorption material atrazine powdered activated carbon

Bulking sludge for PHA production:Energy saving and comparative storage capacity with well-settled sludge

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2012年第10期24卷 1744-1752页

作者： Qinxue Wen Zhiqiang Chen Changyong Wang nanqi ren State Key Laboratory of Urban Water Resource and Environment Harbin Institute of TechnologyHarbin 150090China

Two acetate-fed sequencing batch reactors （SBR） were operated under an aerobic dynamic feeding （ADF） model （SBR#2） and with anaerobic phase before aerobic phase （SBR#1） to select mixed cultures with a high polyhydroxyalkanoates （PHA） storage response. Although kinetic selection based on storage response should bring about a predominance of floc-formers, a bulking sludge with storage response comparable to well-settled sludge was steadily established. An anaerobic phase was introduced before the aerobic phase in the ADF model to improve the sludge settleability （SBR #1）, however, due to the consequent increased feast/famine ratio, the performance of SBR #1, in terms of both the maximum PHB （polyhydroxybutyrate） cell content and APHB, was lower than that of SBR #2. SBR #2 gradually reached a steady state while SBR #1 failed suddenly after 50 days of operation. The maximum specific substrate uptake rate and storage rate for the selected bulking sludge were 0.4 Cmol Ae/（Cmol ***） and 0.18 Cmol Ac/（Cmol ***）, respectively, resulting a yield of 0.45 Cmol PHB/（Cmol Ae） in SBR #2 in the culture enrichment phase. A maximum PHB content of 53% of total suspended solids and PHB storage rate of 1.36 Cmol Ac/（Cmol ***） was achieved at 10.2 hr in batch accumulation tests under nitrogen starvation. The results indicated that it was feasible to utilize filamentous bacteria to accumulate PHA with a rate comparable to well-settled sludge, Furthermore, the lower dissolved oxygen demand of filamentous bacteria would save energy required for aeration in the culture enrichment stage.

关键词： polyhydroxyalkanoates mixed cultures aerobic dynamic feeding bulking sludge feast/famine ratio

Biodegradation of phenol and m-cresol by mutated Candida tropicalis

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2010年第4期22卷 621-626页

作者： Yan Jiang Xun Cai Di Wu nanqi ren State Key Laboratory of Urban Water Resource and Environment Harbin Institute of Technology Harbin 150090 China. Department of Chemical Engineering Daqing Oilfield Engineering Limited Company Daqing 163712 China School of Life Sciences and Chemistry Harbin University Harbin 150016 China

The phenol and m-cresol biodegradations were studied using the mutant strain CTM 2 obtained by the He-Ne laser irradiation on wild-type Candida tropicalis. The results showed that C. tropicalis exhibited the increased capacity of phenolic compounds degradation after laser irradiation. It could degrade 2600 mg/L phenol and 300 mg/L m-cresol by 5% inoculum concentration, respectively. In the dual-substrate biodegradation system, 0-500 mg/L phenol could accelerate m-cresol biodegradation, and 300 mg/L m-cresol could be completely utilized within 46 hr at the presence of 350 mg/L phenol. Besides, the maximum biodegradation of m-cresol could reach 350 mg/L with 80 mg/L phenol within 61 hr. Obviously, phenol, as a growth substrate, could promote CTM 2 to degrade m-cresol, and was always preferentially utilized as carbon source. Comparatively, low-concentration m-cresol could result in a great inhibition on phenol degradation. In addition, the kinetic behaviors of cell growth and substrate biodegradation were described by kinetic model proposed in our laboratory.

关键词： biodegradation the mutant strain CTM 2 phenol m-cresol kinetic

Influence of temperature on the characteristics of aerobic granulation in sequencing batch airlift reactors

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2009年第3期21卷 273-278页

作者： SONG Zhiwei ren nanqi ZHANG Kun TONG Longyan School of Municipal and Environmental Engineering Harbin Institute of Technology Harbin 150001 China School of Resource and Environment Engineering Heilongjiang Institute of Science and Technology Harbin 150027 China

Aerobic granular sludge was cultivated in sequencing batch airlift reactors （SBAR） at 25, 30, and 35℃, respectively. The effect of temperature on the granules characteristics was analyzed and the microbial community structures of the granules were probed using scanning electron microscope （SEM） and polymerase chain reaction-denaturing gradient gel electrophoresis （PCR-DGGE）. The results showed that 30℃ is optimum for matured granule cultivation, where the granules had a more compact structure, better settling ability and higher bioactivity, the oxygen utilization rate （OUR） reached 1.14 mg O2/（g ***） with COD removal rate of 97% and TP removal rate of 75%. The removal efficiency of NH3-N increased from 68.5% to 87.5% along with the temperature increment from 25 to 35℃. The DGGE profiles revealed that the microbial community structure at 25℃ showed the least similarity with those at other temperatures. The sequencing results indicated that the majority of dominant microbes belonged to Actinobacteria and Proteobacterium. Thermomonas sp., Ottowia sp. and Curtobacteriurn ammoniigenes might play important roles at different temperatures, respectively.

关键词： aerobic granules temperature settling ability biological activity PCR-DGGE

Efficient removal and recovery of Cd^(2+)from aqueous solutions by capacitive deionization(CDI)method using biochars

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2023年第17期148卷 10-18页

作者： Zhao Song Lingyu Li Yidi Chen Xiaoguang Duan nanqi ren State Key Laboratory of Urban Water Resource and Environment Shenzhen Key Laboratory of Organic Pollution Prevention and ControlSchool of Civil and Environmental EngineeringHarbin Institute of Technology(Shenzhen)Shenzhen 518055China School of Chemical Engineering and Advanced Materials The University of AdelaideAdelaideSA 5005Australia

Biochars are low-cost and sustainable materials for environmental *** this work,we pre-pared three biochars using pomelo peel(P-BC),algae(A-BC),and corncob(C-BC)to recover Cd^(2+)from wastewater via capacitive deionisation(CDI).A-BC possesses the highest amount of mesopores and nitro-gen functionality and attains the highest removal of Cd^(2+)via physical *** the electro-sorption capacity,C-BC and A-BC perform better capacitive removal of Cd^(2+)than P-BC due to the smaller charge-transfer and mass-transfer ***,this work investigated the impacts of surface morphology,cell voltage,NaCl,initial pH,and Cd^(2+)concentrations on Cd^(2+)capacitive removal and electrode regen-eration *** results indicated that A-BC and C-BC may be prospective materials for Cd^(2+)removal from wastewater by ***,the presence of competing cations at high concentrations may influence the removal of Cd^(2+)at a low level,requiring the modification of A-BC and C-BC in future work.

关键词： Biochar Cd removal Capacitive deionisation Heavy metals Selectivity

Mechanism of powdered activated carbon enhancing caproate production

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2023年第4期34卷 415-419页

作者： Siying Xiang Qinglian Wu Weitong ren Wanqian Guo nanqi ren College of Architecture and Environment Sichuan UniversityChengdu 610065China State Key Laboratory of Urban Water Resource and Environment Harbin Institute of TechnologyHarbin 150090China

Caproate, produced by microbial chain elongation process, is potential to replace the diversified fossilbased products, contributing to carbon neutrality. However, its production performance is far from industrial application, so the cost-effective enhancement measures are highly needed. This study confirmed powdered activated carbon(PAC) has a significant effect on enhancing caproate production *** production, yield, and selectivity of caproate were improved by more than 1-fold by the optimized PAC dosage of 15 g/L, comparing with control. Mechanism investigation from a new visual angle showed that PAC accelerated ethanol oxidation to generate acetyl-Co A, and simultaneously boosted the efficiency of reverse β oxidation(RBO) by promoting the timely reaction of butyrate and acetyl-Co A to synthesis caproate. The addition of PAC also shifted the microbial community by enriching more caproateproducing bacteria but eliminating irrelevant ones. Furthermore, metagenomic analysis revealed that PAC effectively up-regulated the functional genes encoding key enzymes responsible for ethanol oxidation and RBO pathway, which was the root cause for the improved caproate production. This study presented the intrinsic insights into the mechanism of PAC promoting caproate generation, laying a foundation to the scale production of caproate.

关键词： Medium chain fatty acids Caproate Powdered activated carbon Functional genes Metagenome

Acid resistance of methanogenic bacteria in a two-stage anaerobic process treating high concentration methanol wastewater

在线全文

学校读者我要写书评

暂无评论

Frontiers of Environmental Science & Engineering 2007年第1期1卷 53-56页

作者： ZHOU Xuefei ren nanqi State Key Laboratory of Pollution Control and Resource Reuse Tongji UniversityShanghai 200092China Department of Environmental Science and Engineering Harbin Institute of TechnologyHarbin 150090China

In this study,the two-stage upflow anaerobic sludge blanket(UASB)system and batch experiments were employed to evaluate the performance of anaerobic digestion for the treatment of high concentration methanol *** acid resistance of granular sludge and methanogenic bacteria and their metabolizing activity were *** results show that the pH of the first UASB changed from 4.9 to 5.8 and 5.5 to 6.2 for the second ***,these were not the advisable pH levels that common metha-nogenic bacteria could *** methanogenic bacteria of the system,*** barkeri,had some acid resis-tance and could still degrade methanol at pH *** the meth-anogenic bacteria were trained further,their acid resistance would be improved *** sludge of the system could protect the methanogenic bacteria within its body against the impact of the acidic environment and make them degrade methanol at pH *** performance of granular sludge was attributed to its structure,bacteria species,and the distribution of bacterium inside the granule.

关键词： methanol wastewater methanogenic bacteria acid resistance granular sludge upflow anaerobic sludge blanket(UASB) batch culture experiment

Short-term effect of temperature variation on the competition between PAOs and GAOs during acclimation period of an EBPR system

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Environmental Science & Engineering 2011年第2期5卷 277-282页

作者： nanqi ren Han KANG Xiuheng WANG Nan LI State Key Laboratory of Urban Water Resource and Environment Harbin Institute of TechnologyHarbin 150090China

Sequencing batch reactor(SBR)for enhanced biological phosphorus removal(EBPR)processes was used to investigate the impact of the temperature shock on the competition between phosphorus-accumulating organisms(PAOs)and glycogen accumulating organisms(GAOs)in start-up *** the 34 days operation,SBR was set with temperature variation(0-5 d,22±1℃;6-13 d,29±1℃;14-34 d,14±1℃).PAOs and GAOs were analyzed by fluorescent in situ hybridization(FISH),and intracellular polyphosphate granules were stained by *** results showed that the influence of temperature shock on PAOs’abundance was more serious than that on GAOs in the enriching *** sudden and substantially temperature variation,from 22±1℃ to 29±1℃ and then to 14±1℃,the domination of PAOs was *** temperature shock,PAOs’competitive advantages at low temperature that concluded in other study did not appear in our *** mesophilic,GAOs(indicated by Alphaproteobacteria and Gammaproteobacteria)were more temperature adaptive and better grew and took the domination at 14±1℃ in the *** the competition process,organisms of tetrad forming organisms(TFOs)-like shape which were considered as typical GAOs,were *** the evidence of poly-P granules containing by Neisser-straining and result of FISH,these organisms of TFOs-like shape were better to be assumed as adaption state or a special self-protecting shape of PAOs.

关键词： fluorescent in situ hybridization(FISH) tetrad forming organisms(TFOs) temperature variation enhanced biological phosphorus removal(EBPR)