Characterization of the genes involved in nitrogen cycling in wastewater treatment plants using DNA microarray and most probable number-PCR

To improve nitrogen removal performance of wastewater treatment plants (WWTPs), it is essential to understand the behavior of nitrogen cycling communities, which comprise various microorganisms. This study characterized the quantity and diversity of nitrogen cycling genes in various processes of municipal WWTPs by employing two molecular-based methods:most probable number-polymerase chain reaction (MPN-PCR) and DNA microarray. MPN-PCR analysis revealed that gene quantities were not statistically different among processes, suggesting that conventional activated sludge processes (CAS) are similar to nitrogen removal processes in their ability to retain an adequate population of nitrogen cycling microorganisms. Furthermore, most processes in the WWTPs that were researched shared a pattern:the nirS and the bacterial amoA genes were more abundant than the nirK and archaeal amoA genes, respectively. DNA microarray analysis revealed that several kinds of nitrification and denitrification genes were detected in both CAS and anaerobic-oxic processes (AO), whereas limited genes were detected in nitrogen removal processes. Results of this study suggest that CAS maintains a diverse community of nitrogen cycling microorganisms; moreover, the microbial communities in nitrogen removal processes may be specific.

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液氧储罐爆炸事故树分析

采用安全系数工程的方法,对液氧储罐爆炸进行丁事故树分析,通过求事故树最小割集,进行结构重要度分析,从而对液氧储罐爆炸的事故原因进行分析、预测,并提出了相应的预防控制措施。     

焦化废水除油工艺中混凝剂的选择

以焦化废水处理工艺中的实例证实了聚合氯化铝(PAC)加聚丙烯酰胺(PAM)组合的优良除油性能,并从理论上及实际应用中进行了分析,对PAC加PAM组合在焦化废水处理中应用的优缺点进行了比较。     

某冶化公司焦化厂老生化系统改造实践

利用原有的生化脱酚池改造为A＋O＋A生物法,进行生物脱氮,效果很好,处理后的出水全部循环使用,不外排.     

发酵液回流对餐厨垃圾厌氧消化的影响

针对厌氧发酵液回流可提高厌氧系统性能,而不适的回流比例又会造成系统酸化的现象,采用单相连续反应器研究了发酵液回流及不同回流比对餐厨垃圾厌氧消化过程的影响。结果表明:在1 gVS/L的有机负荷下进行三种比例(10%、30%、50%)的发酵液回流使系统日平均产气量比不回流阶段分别提高0.7%、13.0%、4.9%,且对气体甲烷含量无显著影响。回流使VFA降解更充分,也使系统缓冲能力得到调节,但在较高的回流比(50%)下会造成Na+积累从而抑制系统产气性能。     

生物曝气滤池治理医院污水实例及运行管理

废水经格栅去除杂物后,用潜污泵抽至斜板沉淀池,同时加入去磷剂,出水自流进入曝气生物滤池,DO控制在3-5 mg/l,出水进入清水池后再进入消毒池,二氧化氯加入量为30 g/M3 废水,停留时间1.5 h.曝气生物滤池12～24小时进行反冲洗一次,反冲洗出水再返回调节池、斜板沉淀池每天排泥一次,排入污泥沉淀池,其上清液进入调节池,剩余污泥定期消毒后环卫清污车运走.经处理后水质达到(GB8978-1996)一级排放标准.以曝气生物滤池为主工艺处理医院污水,工艺可靠、出水稳定,但必须按严格的管理程序、即质量测试、操作设备、工艺技术管理环节,同时设备必须一年进行一次大修,处理后水质稳定达标排放是可行的. 控制在3-5 mg/l,出水进入清水池后再进入消毒池,二氧化氯加入量为30 g/M3 废水,停留时间1.5 h.曝气生物滤池12～24小时进行反冲洗一次,反冲洗出水再返回调节池、斜板沉淀池每天排泥一次,排入污泥沉淀池,其上清液进入调节池,剩余污泥定期消毒后环卫清污车运走.经处理后水质达到(GB8978-1996)一级排放标准.以曝气生物滤池为主工艺处理医院污水,工艺可靠、出水稳定,但必须按严格的管理程序、即质量测试、 作设备、工艺技术管理环节,同时设备必须一年进行一次大修,处理     

防空干道地下水作为化工工艺用水工程改造实例

防空干道地下水质YD390-400mg／l,TDS750 mg,／l,经强化纤维过滤-OR低压反渗透装置处理后水质达到钛白粉生产工艺用水标准。YD〈200mg/l,TDS〈450mg/l。工艺条件：处理量7000M^3／d,净水荆加入量1501／h,反渗透设计压力2．5Mpa,工作压力1．3Mpa,工作温度10℃-30℃,采用芳香族聚酰胺反渗透膜,设计压力4．0Mpa,工作压力1．5Mpa,工作温度10℃-40℃。同时,该处理系统占地面积小,工艺成熟,简洁、高效,在确保出水达标的同时降低了运行成本。在强化纤维过滤中采用GM多功能净水剂,具有絮凝快,分离速度快,分界清楚,浊度去除高。反渗透工序分离过程不需加热,没有相的变化,具有耗能较少,设备体积小、操作简单、适应性强,应用广泛。     

上海市闵行区综合水环境质量分析及研究

分析了上海市闵行区水环境质量的现状.采用同济大学开发的水质标识指数法,对闵行区2001～2005年间三大水系(即淀南片、淀北片及浦东片)的综合水质、综合水质按月变化情况、主干河流沿程变化等进行了分析.提出了改善河道水动力、河道曝气复氧、建设城市污水处理厂及完善污水管网、监测计划的前瞻性、修建护坡及绿化带等建议.     

Study on Development of the West of Shandong Province Based on Overall Regional Development Planning Pattern

The overall regional development planning pattern has been considered to be a new and effective pattern as for development of provincial economy. The article analyzed the current conditions of the west of Shandong Province and tried to find the generation mechanisms of current non-balanced economic development of Shandong Province. And then approaches to regional development were put forward according to the theory of regional development pattern as a whole.     

The spatial-temporal differentiation of green land use in Beijing–Tianjin–Hebei urban agglomeration

ABSTRACT

As the space carrier of the construction of ecological civilization, land’s green and efficient utilization is an important guarantee for realizing national sustainable development. Based on traditional land evaluation, this paper scientifically defines the green land use, puts land as one of the production factors, and brings energy consumption, environmental pollution, etc. into the input-output system to measure the green land utilization efficiency of the urban construction land of Beijing-Tianjin-Hebei Urban Agglomeration from 2006 to 2016. The study shows that the overall efficiency variation of the urban agglomeration is related with the land and environment policies. Efficiency of 2016 is higher than that of 2006, and energy and environment are the principal factors affecting the green land use. The efficiency of each city is positively correlated with its economic development, negatively correlated with the construction land expansion. Efficiency gaps in different cities are expanding. There is positive correlation with overall weak space between cities, and the partial spatial agglomeration phenomenon appears. Therefore, the green land use efficiency could be improved by improving land utilization efficiency, coordinating economic growth of construction land utilization with environmental protection and taking feasible ways to transregional renovation of the stock ecological land utilization, etc.