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Jin X.,Peking University | Xia D.,Peking University | Ma Z.,Beijing Origin Water Technology Co. | Jae H.K.,Peking University | Xu Q.,Peking University
Chinese Journal of Environmental Engineering | Year: 2015

In order to study the effects of different aerobic pretreatments on methane production from food waste, three simulated anaerobic bioreactors were constructed, including traditional anaerobic bioreactor C1, upper-layer aerobic-anaerobic bioreactor C2 and bottom aerobic-anaerobic bioreactor C3. Results indicated that C1 was maintained at the lag-phase of methane production due to the accumulation of volatile fatty acids. However, the lag time of methane production in C2 and C3 could be reduced to less than 10 days. The aerobic pretreatment of C2 and C3 was capable to increase the aerobic degradation of easily hydrolysed fractions and the excess volatile fatty acids. After stopping upper layer aeration on the 32nd day, methane concentration of C2 could increase to above 50% within 27 days. And the methane production rate increased quickly, arriving to the peak value of 773 mL/(kg·d) on the 81st day. For C3, bottom aeration ceased on the 11st day, even though methane concentration reached to over 50% within 22 days, the subsequent methane production rate decreased before gradually increased again. The methane production rate in C3 could only achieve 517 mL/(kg·d). Upper-layer aerobic pretreatment might need relatively longer time, but the start-up of methane generation was accelerated. In addition, compared to bottom aerobic pretreatment, the subsequent methanogenesis process of upper-layer aerobic pretreatment was more stable and it could reach to higher methane production rate. ©, 2015, Science Press. All right reserved.

Zhu L.-J.,Zhejiang University | Zhu L.-P.,Zhejiang University | Xu Y.-Y.,Zhejiang University | Zhu B.-K.,Zhejiang University | And 2 more authors.
Gongneng Cailiao/Journal of Functional Materials | Year: 2014

The BCP-g-SiO2 NPs were first prepared by grafting block copolymer of poly(methylmethacrylate) and poly(2-(dimethylamino)ethyl methacrylate) brushes onto SiO2 NPs via surface-initiated reversible addition fragmentation chain transfer (RAFT) polymerization. Then the BCP-g-SiO2 NPs were blended with PVDF to prepare PVDF/BCP-g-SiO2 organic-inorganic hybrid membranes by the traditional non-solvent induced phase separation (NIPS) method. Subsequently, the PDMAEMA chains were zwitterionicalized by 1, 3-propane sultone (1, 3-PS). Therefore, the surface zwitterionicalization PVDF/BCP-g-SiO2 organic-inorganic hybrid membranes were successful prepared. The hydrophilicity and antifouling ability of the PVDF membrane were significantly enhanced after surface zwitterionicalization. Therefore, it was an effective method to modify the PVDF membrane using BCP-g-SiO2 NPs as additive together with surface zwitterionicalizationa.

Yang Y.,Tianjin Polytechnic University | Lin Z.,Beijing Originwater Technology Co
Advanced Materials Research | Year: 2012

Di-(2-ethylhexyl) phthalate (DEHP) is one of the most common plasticizers, it have a wide variety of industrial, agricultural and domestic applications. The degradation characteristics of DEHP in water by the advanced oxidation process O 3, UV and UV/O 3 were respectively studied. The effects of ozone concentration, DEHP concentration and pH on the removal rate of DEHP were investigated. The experimental results showed that UV was not able to remove DEHP significantly. However, O 3 or the combination of O 3 with UV could degrade DEHP effectively. Both the increase in the O 3 concentration and the initial pH value of the system benefited the DEHP removal. © (2012) Trans Tech Publications, Switzerland.

Wang R.,Beijing University of Technology | Wang R.,Beijing Origin Water Technology Co. | Hao R.,Beijing University of Technology | Zhao W.,Beijing University of Technology
Chinese Journal of Environmental Engineering | Year: 2016

To improve the denitrification rate of starch/polyvinyl alcohol(PVA) and effectively control the carbon release rate, a new slow-release organic carbon source(SOC) was synthesized by adding acetate starch/hydrophobic emulsifier(SPAN80), secondary encapsulation and surface cross-linking reaction. The optimum material ratio, nitrogen removal efficiency and release model of SOC were investigated by carbon release and denitrification experiments. The results showed that the denitrification efficiency would ascend rapidly with augmenting of starch content in SOC while the rise of release speed may increase the concentration of COD in the effluent. When the content of starch was 58. 2%, the appropriate carbon release rate and nitrogen removal efficiency could be obtained and the nitrate removal efficiency, average denitrification rate and the effluent concentration of COD could reach 100%, 11. 67 mg/(L·h) and 27. 65 mg/L, as the carbon emission and utilization achieved a balance. So the high nitrogen removal efficiency, long life cycle and controlled carbon release rate made the new SOC suitable for engineering application. © 2016, Science Press. All right reserved.

Yan X.,Tsinghua University | Xiao K.,Tsinghua University | Xiao K.,University of Chinese Academy of Sciences | Liang S.,Tsinghua University | And 6 more authors.
Bioresource Technology | Year: 2015

Baffles are a key component of an airlift membrane bioreactor (MBR), which could enhance membrane surface shear for fouling control. In order to obtain an optimal hydraulic condition of the reactor, the effects of baffle location and size were systematically explored in this study. Computational fluid dynamics (CFD) was used to investigate the hydrodynamics in a bench-scale airlift flat sheet MBR with various baffle locations and sizes. Validated simulation results showed that side baffles were more effective in elevating membrane surface shear than front baffles. The maximum average shear stress was achieved by adjusting baffle size when both front and side baffles were installed. With the optimized baffle configuration, the shear stress was 10-30% higher than that without baffles at a same aeration intensity (specific air demand per membrane area in the range of 0-0.45m3m-2h-1). The effectiveness of baffles was particularly prominent at lower aeration intensities. © 2014 Elsevier Ltd.

Beijing Originwater Technology Co. | Date: 2010-09-09

Water sterilizers; Water purifying apparatus and machines; Filters for drinking water; Purification installations for sewage; Water purification installations; Sanitary apparatus and installations; Water distribution installations; Water supply installations; Gas scrubbing apparatus; Cooling appliances and installations. Water treating; Air purification; Decontamination of hazardous materials; Recycling of waste and trash; Colour separation services; Food and drink preservation; Cloth waterproofing; Metal casting; Assembling of materials for others; Production of Energy.

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