不同基质浓度下SBR进水方式对厌氧氨氧化的影响

采用厌氧SBR反应器,分别以配水培养和以实际晚期垃圾渗滤液培养的厌氧氨氧化菌为研究对象,考察了不同基质浓度下,SBR改进式连续进水方式与一次性进水方式对厌氧氨氧化工艺运行性能的影响.结果表明,当处理人工配水时,在中低进水浓度下(NO2--N￡400mg/L),与改进式连续进水方式相比,宜采用一次性进水方式运行;在高进水浓度下(NO2--N3400mg/L)改进式连续进水方式比一次性进水方式优势明显,特别是在5h改进式连续进水方式下,平均比污泥脱氮速率增加至39.11mgN/(gVSS·h),相比一次进水方式效率提高40%.当处理进水NO2--N浓度为(300±20)mg/L的实际晚期垃圾渗滤液时, 5h改进式连续进水的SBR比污泥脱氮速率最高.由于晚期渗滤液较配水成分复杂,使得厌氧氨氧化菌面临有机物和有害物质的影响,其厌氧氨氧化的反应速率低于同等基质浓度配水条件下的厌氧氨氧化反应速率.     

HCPA-UF-MBR组合工艺处理低温高色高氨氮水源水研究

将高浓度纯化凹凸棒土(HCPA)投加至UF-MBR中,形成HCPA-UF-MBR组合工艺,研究HCPA-UF-MBR、UF-MBR两平行系统对低温高色高氨氮水源水的除污效果、反应器内活性污泥性能及膜污染情况,考察HCPA的作用机理与效能.结果表明,HCPA-UF-MBR对色度、CODMn、NH -N、TN的平均去除率为94.60%、81.61%、98.44%、58.30%,出水NO -N、NO -N浓度均较低;HCPA投加后,UF-MBR的除污效果与抗冲击负荷能力增强,污泥总活性与硝化活性分别提高了9.09%、105.88%,反应器达到稳定时间短且波动小,内部活性污泥硝化反硝化过程更充分;此外,HCPA吸附混合液中部分有机物,改善了污泥混合液性能,使膜表面滤饼层较疏松且透水性较好,有效地减轻了膜污染程度.     

Indicating landfill stabilization state by using leachate property from Laogang Refuse Landfill

Variation and evolution process of leachate can be applied as a reference for landfill stabilization phase. In this work, leachates with different ages were collected from Laogang Refuse Landfill, and characterized with 14 key parameters. Simultaneously, principal component analysis （PCA） was applied to develop a synthetic parameter-F based on these 14 parameters, and a logarithm equation was simulated for the landfill stabilization process finally. It was predicted that leachates would meet Class I and Class II in standard for pollution control on the landfill site of municipal solid waste （GB 16889-1997） after 32 years and 22 years disposal under the natural attenuation in the humid and warm southern areas of China, respectively. The predication of landfill state would be more accurate and useful according to the synthetic parameter F of leachate from a working landfill.     

Family–work conflict and job performance: A diary study of boundary conditions and mechanisms

In this study, we used a within‐person daily research paradigm to examine the relationship between daily family–work conflict (FWC) and daily job performance. On the basis of theory on dynamic behavior, we hypothesized that concentration serves as a mechanism through which daily FWC impairs daily job performance. We further predicted that psychological detachment from work during time‐off (i.e., mentally switching off) buffers the negative relationship between daily FWC and daily job performance. Ninety‐five employees completed daily surveys over one workweek. Multilevel modeling results showed that daily FWC was negatively associated with daily job performance and that concentration mediated this relationship. Furthermore, general psychological detachment, but not daily psychological detachment, buffered the negative relationship between daily FWC and daily job performance. The current findings suggest that daily FWC has negative performance implications and that the general level rather than the daily level of psychological detachment from work helps alleviate the negative implications. Copyright © 2013 John Wiley & Sons, Ltd.     

北京市某垃圾卫生填埋场堆山及覆盖工程实例

填埋场堆山及覆盖工程是指垃圾从地面向上填埋作业,至设计标高或填埋场停止使用高度的过程。为避免堆体沉降过大对堆体的稳定造成影响,根据勘察报告对垃圾填埋区进行的沉降分析,利用陈腐垃圾对沉降最大区域进行压实、垫高,保证垃圾堆体压实密度大于0.9;为减少渗沥液的产生保证渗沥液、沼气收集及导排系统安全有效的运行,采用基础构建的方式减少填埋作业面,从而减少雨季雨水的渗入;待堆体形成后,通过在堆体顶部及边坡铺设防渗及导排层对渗沥液和沼气进行疏导和收集,降低渗沥液和沼气对堆体稳定以及周边环境造成的影响,并铺设生态恢复层,美化环境。     

多孔水化硅酸钙的制备及其磷回收特性

为实现磷资源的可持续利用,以环境废弃物电石渣为钙质材料,以白碳黑为硅质材料合成CSH(水化硅酸钙),以该材料为晶种,以结晶形成羟基磷灰石的形式从含磷废水中回收磷,重点研究了不同钙硅比〔c(CaO)/c(SiO₂)〕条件下制备的CSH对含磷废水中磷的回收特性. 结果表明,钙硅比为1.8∶1时所得的CSH结构更疏松、表面分布有较多的孔隙, 较大的比表面积使其具有较好的溶钙能力. 钙硅比为1.8∶1的CSH最佳磷回收工艺条件:反应时间为60min,CSH投加量为4g/L,搅拌强度为40r/min. 在该条件下重复除磷15次以后,回收产物中w(P)达到17.56%,说明CSH具有良好的磷回收性能. 对回收磷前后的CSH进行了XRD图谱分析和FTIR分析发现,溶液中的磷主要生成了羟基磷灰石并嵌入到CSH中. 基于回收磷的目的,CSH可以用于处理ρ(P)较高的工业废水,或者是生物除磷系统中的污泥厌氧释磷液中,回收磷后的产品可作为含磷矿石或者磷肥加以利用.      

Toxicity of cypermethrin on total lipids and free fatty acids in liver,muscle, kidney and ovary of Clarias batrachus (L) and recovery response

Alterations in the levels of lipid metabolites, total lipids and free fatty acids, were studied in physiologically important tissues viz; liver, muscle, kidney and ovary of a freshwater edible fish Clarias batrachus. The fish was exposed to sublethal concentration (1/3 of LC50 value for 96?h) of a synthetic pyrethroid insecticide, cypermethrin for 1, 5 and 10 days. After 10 days of exposure, fish were released into fresh water and total lipids and free fatty acids were determined at intervals of 1, 5 and 10 days to assess fish recovery response after cessation of cypermethrin exposure. Fish showed an increased rate of lipogenesis in liver, muscle, kidney and ovary during the exposure period followed by a decrease after transfer of fish into fresh water. There was also an elevation in liver and kidney free fatty acids contents, while the muscle and ovary free fatty acid contents were reduced during exposure period. The alterations in free fatty acids were restored to near normal values after 10 days of cessation of exposure.     

In vitro genotoxicity of fly ash leachate in earthworm coelomocytes

Fly ash is the major coal combustion byproduct from thermal power plants. Considering its plant–nourishing constituents, its soil amendment in farmland is one of its promoted disposal methods. A substantial amount of heavy metals present in fly ash, which may leach out due to rainwater or irrigation water, may cause serious problem with long term use, especially to soil organisms. These metals may cause DNA damage through Reactive Oxygen Species (ROS) generation. In the present study, single cell gel electrophoresis [(SCGE) i.e., comet assay] was used to detect DNA damage in earthworm (Dichogaster curgensis) coelomocytes, following an in vitro exposure. Significant DNA damage was observed at the lowest concentration of fly ash leachate (6.25%) examined. DNA damage by all the tested concentrations (6.25%, 12.5%, 25%, 50%) differed significantly (p?<?0.001) from that of the negative control. Hence, long-term application of fly ash might prove harmful for earthworm populations.     

武威绿洲农业水足迹变化及其驱动机制研究

农业活动通过改变绿洲赖以生存的水生态系统而影响着绿洲的稳定性。1950-2007年武威绿洲农业水足迹上涨了近7倍,而农业水足迹效率仅提高1.75倍;粮食作物水足迹比例过大,57 a间平均达74.32%,其中,2002年以前粮食作物水足迹比例呈下降趋势,但在2002年达到最低点58.63%之后开始出现反弹。人口增长和人民生活需求所驱动的以粮食生产为主体的农业规模扩大和农业开发强度加大,是农业水足迹增长的主要原因。适当压缩农业规模,加快农业内部结构调整,加大政府对农业节水灌溉工程的投入和农业节水技术的推广,是控制武威绿洲农业水足迹增长过快,维护绿洲生态系统稳定的有效方式。     

经济增长质量与能源效率是一致的吗?

论文从全社会节能的角度提出全社会能源效率的概念,构建了经济增长质量指标体系,并基于1997—2007 年中国30 个省份的面板数据,采用Malmquist DEA方法测算了广义技术进步指数并进行分解,然后运用面板方法分析了经济增长质量与能源效率的作用机制,研究结果表明经济增长质量与能源效率是不完全一致的,具体表现为:改善环境质量与提高能源效率是一致的,技术进步与产业结构升级能够促进能源效率,但出口比重的增加和生活水平的提高会抑制能源效率的改进。技术进步、技术效率、纯技术效率和规模效率对全社会能源效率有正向影响,技术效率的作用大于技术进步,纯技术效率和规模效率的下降削弱了技术进步的正向作用。