Biological nutrient removal by internal circulation upflow sludge blanket reactor after landfill leachate pretreatment

The removal of biological nutrient from mature landfill leachate with a high nitrogen load by an internal circulation upflow sludge blanket （ICUSB） reactor was studied. The reactor is a set of anaerobic-anoxic-aerobic （A^2/O） bioreactors, developed on the basis of an expended granular sludge blanket （EGSB）, granular sequencing batch reactor （GSBR） and intermittent cycle extended aeration system （ICEAS）. Leachate was subjected to stripping by agitation process and poly ferric sulfate coagulation as a pretreatment process, in order to reduce both ammonia toxicity to microorganisms and the organic contents. The reactor was operated under three different operating systems, consisting of recycling sludge with air （A^2/O）, recycling sludge without air （low oxygen） and a combination of both （A^2/O and low oxygen）. The lowest effluent nutrient levels were realised by the combined system of A^2/O and low oxygen, which resulted in effluent of chemical oxygen demand （COD）, NH3-N and biological oxygen demand （BOD5） concentrations of 98.20, 13.50 and 22.50 mg/L. The optimal operating conditions for the efficient removal of biological nutrient using the ICUSB reactor were examined to evaluate the influence of the parameters on its performance. The results showed that average removal efflciencies of COD and NH3- N of 96.49% and 99.39%, respectively were achieved under the condition of a hydraulic retention time of 12 hr, including 4 hr of pumping air into the reactor, with dissolved oxygen at an rate of 4 mg/L and an upflow velocity 2 m/hr. These combined processes were successfully employed and effectively decreased pollutant loading.     

Effects of idle time on biological phosphorus removal by sequencing batch reactors

Three identical sequencing batch reactors （SBRs） were operated to investigate the effects of various idle times on the biological phosphorus （P） removal. The idle times were set to 3 hr （R1）, 10 hr （R2） and 17 hr （R3）. The results showed that the idle time of a SBR had potential impact on biological phosphorus removal, especially when the influent phosphorus concentration increased. The phosphorus removal efficiencies of the R2 and R3 systems declined dramatically compared with the stable R1 system, and the Prelease and P-uptake rates of the R3 system in particular decreased dramatically. The PCR-DGGE analysis showed that uncultured Pseudomonas sp. （GQ183242.1） and β-Proteobacteria （AY823971） were the dominant phosphorus removal bacteria for the R1 and R2 systems, while uncultured γ-Proteobacteria were the dominant phosphorus removal bacteria for the R3 system. Glycogen-accumulating organisms （GAOs）, such as uncultured Sphingomonas sp. （AM889077）, were found in the R2 and R3 systems. Overall, the R1 system was the most stable and exhibited the best phosphorus removal efficiency. It was found that although the idle time can be prolonged to allow the formation of intracellular polymers when the phosphorus concentration of the influent is low, systems with a long idle time can become unstable when the influent phosphorus concentration is increased.     

混凝—淹没式曝气生物滤池组合工艺处理洗衣废水

利用混凝与淹没式曝气生物滤池相结合的处理工艺对洗衣废水进行了90d的研究。工程运行结果表明,洗衣废水经混凝后,COD平均下降52.9%,TP平均下降92.1%。混凝出水再经过曝气生物滤池进一步处理,最终出水水质为COD≤50mg/L,NH3≤2.57mg/L,TP≤0.27mg/L。     

连续搅拌釜式反应器放热反应失控事故预防

运用敏感度方法研究连续搅拌釜式反应器(CSTR)放热反应的参数敏感性行为及规律,探讨CSTR反应器的安全操作区域和敏感操作区域。研究发现:无因次活化能小于4的反应系统,其整个操作参数空间都是安全的;无因次活化能大于4的反应系统,只有选择无因次活化能小于其临界值,反应系统才能安全、稳定地运行;临界无因次反应热的值与无因次丹克莱尔数和无因次反应热有关;丹克莱尔数和无因次反应热越大,则临界无因次反应热越小,安全操作区域也越小。     

管壳式余热锅炉适用标准的探讨

通过对管壳式余热锅炉的典型结构分析和主要受压元件设计、制造、检验等方面适用标准的探讨，笔者建议有关的标准制定与管理部门应及时地编制专门的《管壳式余热锅炉》标准或相关规定，以规范管壳式余热锅炉设计、制造、检验，保障产品和人身安全。     

三种MBR工艺在中水回用中的应用研究

我国是淡水资源匮乏的国家，探讨中水回用技术具有一定的经济效益和社会效益；文章从一体式MBR、分置式MBR、复合式MBR三种工艺原理及实践运用为基础，探讨三种工艺的各自特点，并从经济和工艺等方面予以比较。为不同规模和技术条件的企业、污水处理厂选取适当的工艺类型提供参考。     

污水处理厂出水提标改造设备——方形模块式定盘过滤器

目前市场上出现很多污水提标设施,为了节约水资源,解决发展中用水问题,提高废水的排放标已成为政府和企业的关注点。本文详细介绍了当前污水提标新技术设备方形模块式定盘过滤器,更多说明了它的特点和应用领域,为废水的去向提供了一个新的思路。     

蓄热式加热炉炉体与蓄热系统损坏原因分析及防护措施

针对公司现有蓄热式加热炉炉墙、炉顶和蓄热系统常出现的损坏现象,正常的生产运行带来了一定影响,结合多年的实践经验,进行科学分析,并提出有效的解决措施。     

群众工作社会工作融合促进陌生人社区协商共治研究

社区是人民美好生活的重要载体,是国家治理的重要组成。随着住房商品化发展而形成的陌生人社区,比重和治理难度都较大,呈现治理单向化、碎片化和悬浮化等状态;矛盾纠纷得不到及时有效化解、公共事务陷入公地悲剧等问题,直接影响了居民的获得感和幸福感。群众工作和社会工作融合,依靠群众工作的深度扎根,推进党的领导和组织功能再深入,发挥社会工作的专业优势,破解基层自治失灵的难题;从职能融合和方法互鉴等方面推动社区治理体系完善和治理能力提升;紧密协作构建协商平台、落实协商民主、提升协商效果,促进社区从单向型治理走向互动型的协商式共同治理,使基层自治逐步走向善治。