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试验对传统两段式生物反应器(TSBR)进行了改进,二段采用生物膜-膜生物反应器(BMBR);在一段HRT=SRT=2.82~4.23h,二段HRT=6.44~9.66h、SRT→∞,每日空曝气8h的运行条件下,对该工艺进行了试验研究。结果表明,系统稳定后,出水水质稳定,CODc、NH4^ -N和TP的去除效率分别为95%、80%和60%以上,膜污染得到了有效控制。 相似文献
595.
A new environmental chamber for evaluation of gas-phase chemical mechanisms and secondary aerosol formation 总被引:1,自引:0,他引:1
William P.L. Carter David R. Cocker III Dennis R. Fitz Irina L. Malkina Kurt Bumiller Claudia G. Sauer John T. Pisano Charles Bufalino Chen Song 《Atmospheric environment (Oxford, England : 1994)》2005,39(40):7768-7788
A new state-of-the-art indoor environmental chamber facility for the study of atmospheric processes leading to the formation of ozone and secondary organic aerosol (SOA) has been constructed and characterized. The chamber is designed for atmospheric chemical mechanism evaluation at low reactant concentrations under well-controlled environmental conditions. It consists of two collapsible 90 m3 FEP Teflon film reactors on pressure-controlled moveable frameworks inside a temperature-controlled enclosure flushed with purified air. Solar radiation is simulated with either a 200 kW Argon arc lamp or multiple blacklamps. Results of initial characterization experiments, all carried out at 300–305 K under dry conditions, concerning NOx and formaldehyde offgasing, radical sources, particle loss rates, and background PM formation are described. Results of initial single organic–NOx and simplified ambient surrogate–NOx experiments to demonstrate the utility of the facility for mechanism evaluation under low NOx conditions are summarized and compared with the predictions of the SAPRC-99 chemical mechanism. Overall, the results of the initial characterization and evaluation indicate that this new environmental chamber can provide high quality mechanism evaluation data for experiments with NOx levels as low as 2 ppb, though the results indicate some problems with the gas-phase mechanism that need further study. Initial evaluation experiments for SOA formation, also carried out under dry conditions, indicate that the chamber can provide high quality secondary aerosol formation data at relatively low hydrocarbon concentrations. 相似文献
596.
Biofiltration pretreatment for reverse osmosis (RO) membrane in a water reclamation system 总被引:2,自引:0,他引:2
Biofouling control is considered as a major challenge in operating membrane systems. A lab-scale RO system was setup at a local water reclamation plant to study the feasibility of using biofiltration as a pretreatment process to control the biofouling. The biological activity in the RO system (feed, product, reject streams) was tested using the standard serial dilution plating technique. Operational parameters such as differential pressure (DP) and permeate flowrate of the system were also monitored. Effects of biofilter on AOC and DOC removals were investigated. Biofiltration was found to be a viable way of assimilable organic carbon (AOC) and dissolved organic carbon (DOC) removals, with removal efficiencies of 40-49% and 35-45% at an empty bed contact time (EBCT) of 30 min. It was also found that using the biofiltration as a pretreatment reduced the rate of biofouling. It took only about 72 h for biofouling to have a significant impact on the performance of the RO membrane, when the system was operated without using biofiltration as pretreatment. There was, however, a five times increase in operational length to more than 300 h when biofiltration was used. This study presented the suitability of the biofilter as an economical and simple way of biofouling control for RO membrane. 相似文献
597.
Feed spacers in spiral-wound reverse osmosis membrane modules are highly susceptible to deposition or attachment of suspended particulates and organic matters in the feed stream. This type of fouling can cause a significant pressure drop along the membrane channel (differential pressure) without much effect on the average permeate flux. In practical applications, membrane cleaning is often triggered when the differential pressure in a membrane channel exceeds a threshold value. A mathematical model was developed to simulate the development of differential pressure in the feed channel resulting from foulant capture by the feed spacers. Simulations were carried out to investigate and demonstrate the effect of various parameters on differential pressures in the membrane channel. Differential pressures observed in a two-stage reverse osmosis water reclamation plant were simulated with the model, and the results showed that the model could adequately describe the increase of differential pressure with operating time in the reverse osmosis plant. 相似文献
598.
高浓度复合型聚铁硅絮凝剂PFSS和PSFS的形态分布研究 总被引:1,自引:0,他引:1
采用紫外分光光度法、逐时络合比色法和红外图谱从不同角度对高浓度聚合硫酸铁硅和聚合硅酸铁的形态分布及转化规律进行了探讨。紫外吸收表明,聚铁硅絮凝剂中主要以Fe(OH)+2、Fe2(OH)4+2等二聚体为主,而且还有三聚体或其他聚合形态的存在;逐时络合分析显示,复合型聚铁硅体系中硅形态以Si(c)为主,铁形态以Fe(a)和Fe(c)为主;红外图谱证实高浓度聚铁硅是以羟桥为主结构连接的高分子复合物,在1100cm-1附近M—OH—M的振动证明有铁羟基及其聚合态存在,且其形态区别于PFS。 相似文献
599.
明确指导方针建立市场化机制推进环境保护与经济建设双赢 总被引:2,自引:0,他引:2
总述了“九五”期间我国环境保护主要成就,并明确指出“十五”期间环境保护的指导方针,指出为实现“十五”环境保护目标,推进环境保护与经济建设双赢,必须建立面向市场的环境保护机制,依靠科技创新,发展绿色经济。 相似文献
600.
有毒化学品销毁设施的环境保护 总被引:2,自引:0,他引:2
销毁有毒化学品时最重要的是确保人员安全与健康,以及生态环境安全。因此,其销毁活动必须遵守严格的安全与环保规定。介绍了有毒化学品销毁设施的安全与环境设计标准、控制工艺废弃物,尤其是有毒废气的具体做法,以及销毁设施内部、作业区附近的环境监测方案。这些环境保护措施同样也适用于其他有毒化学品销毁设施。 相似文献