序批式生物膜反应器同步硝化反硝化的曝气时问控制及其机制分析

装有鲍尔环填料的序批式生物膜反应器(SBBR)具有很好的同步硝化反硝化(SND)效果.从试验结果可以看出,SBBR具备了生成和保存内碳源以及产生缺氧区的良好条件;当硝化结束后,应立即停止曝气,可以降低出水TN并实现节能.分析了生物膜内各种基质、DO、聚β-羟基丁酸(PHB)的变化曲线.描述了生物膜内发生SND的过程和机制,并提出了SBBR中达到良好SND效果的曝气时间控制方式.     

Pathway of 17��-estradiol degradation by Nitrosomonas europaea and reduction in 17��-estradiol-derived estrogenic activity

In recent years, natural and synthetic estrogens have been recognized as endocrine disruptors in aquatic organisms. Although natural and synthetic estrogens are known to be degraded by microbes, only limited information about their degradation pathways is available. Here, we studied the degradation pathways of a natural estrogen, 17β-estradiol, by the nitrifying microorganism Nitrosomonas europaea, and we determined whether the degradation products of 17β-estradiol had estrogenic activity. To identify the degradation products, we subjected the culture solution to solid-phase extraction, and the extract was analyzed by gas chromatography–mass spectrometry. The potential estrogenic activity of the degradation products was investigated by means of a yeast two-hybrid assay. 1,3,5(10),16-Estratetraen-3-ol (estratetraenol) was newly identified as a degradation intermediate produced by dehydration of 17β-estradiol. Estratetraenol was also degraded by N. europaea, and its degradation rate was faster than that of 17β-estradiol. The two-hybrid assay confirmed that estratetraenol acted as a ligand for the estrogen receptor; estratetraenol thus has potential estrogenic activity. N. europaea eliminated the estrogenic activity derived from 17β-estradiol. This paper is the first to report dehydration as a mechanism of microbial estrogen degradation.     

模糊ISODATA聚类在矿山环境评价中的应用

矿山开采一方面繁荣了一方经济,另一方面也对生态环境造成了破坏和污染。被破坏和污染的矿山环境需要治理,治理的前提是如何适时监测和正确评价矿山环境。本文运用模糊数学中的模糊ISODATA聚类．建立模糊关系矩阵,使问题从地质变量空间向评语空间转换,通过对云南个旧某地区的废弃矿区土壤进行测试,应用该方法进行地质环境评价,提供了科学合理的治理依据。     

1998年长江大洪水与大气环流和海温异常分析

概述了引起１９９８年长江大洪水的雨情,从天气气候角度分析了１９９８年长江流域降水异常偏多的原因。指出了最直接的原因是副高移动的反常,特别７月１５日以后副高突然南撤南海季风爆发晚,南亚和东亚季风强度偏弱、夏季赤道辐合带偏弱热带地区台风生成少、生成时间晚,     

土壤固相不同组分对镉,锌吸持的研究

本文选用三种不同类型的土壤，用连续提取法依次去除土壤固相中碳酸盐（石灰性土壤）、锰、有机质、无定型氧化铁和晶型氧化铁组分，制得分离某一组分或某几个组分后的土壤钙饱和的样品，藉此研究土壤固相各组分对重金属Ｃｄ和Ｚｎ吸持的影响，研究结果表明，不同土壤去除某一组分或多个组分后对Ｃｄ和Ｚｎ吸持的影响是不同的，土壤固相中组分的相互作用可能是其主要原因。     

The chronic effects of oil pollution on marine phytoplankton in a subtropical bay, China

To evaluate the effects of crude oil water accommodated fraction (WAF) on marine phytoplankton community, natural phytoplankton collected seasonally from the Yueqing bay were exposed to eight groups of crude oil WAF for 15 days under laboratory conditions. Chlorophyll a and cell density were measured, and species of phytoplankton were identified every 24 h to reflect the change of phytoplankton community. The results showed that (1) High concentrations (??2.28 mg l^???1) of oil pollution would greatly restrain phytoplankton growth (p?< 0.001), decrease chlorophyll a content and cell density, whereas low concentrations (??1.21 mg l^???1) did not restrain its growth but rather promoted the phytoplankton growth. (2) The biodiversity, evenness, and species number of phytoplankton were all significantly influenced by crude oil WAF in all seasons (p?<?0.001). (3) The dominant species changes were different under different pollutant concentrations in different seasons. Different species had different tolerances to the oil pollution, thus leading to abnormal succession.     

南京城市化进程与热岛效应的初步研究

城市化过程对气候变化有着重要影响,全面而准确的分析城市化进程是十分重要的。以南京市为例,利用南京地区1985~2007年年平均气温和1985~2010年源于统计年鉴的4类城市化指标数据,使用人工神经网络方法以及综合指标法,分析了南京市城市化综合发展水平变化及其热岛效应的关系。结果表明：南京城市化进程分为稳步发展阶段（1985~2000年）和快速发展阶段（2001~2010年）,城市化综合评价指数增长速率分别为01/10a和06/10a;南京市1985~2007年年平均气温呈波动式上升,平均城郊温差03℃,温度差异明显,总体上热岛强度呈波动增加趋势,尤其 2000年之后,以019℃/10a的速率迅速增加;热岛强度与城市化综合评价指数之间相关系数为075,呈显著地线性相关关系     

城市垃圾分类回收中的循环经济

在分析我国城市垃圾现状的基础上，从资源、环境和社会可持续发展的角度，提出应在遵循循环经济的“三R”原则基础上对城市垃圾进行分类、收集、处理，并论述了实现措施。     

Effects of nature organic matters and hydrated metal oxides on the anaerobic degradation of lindane,p,p''''-DDT and HCB in sediments

IntroductionLindane ,p,p’ DDTandHCBaresemivolatileandlipophilic ,andtheyfallintotheclassofcompoundsdescribedaspersistentorganicpollutants.Moreover,thesecompoundshavebeenidentifiedaspotentendocrinedisrupters(Smith ,2 0 0 2 ;Willett,1 998;Robert,2 0 0 1 ) .Ithasbeenreportedchlorinatedorganiccompoundscanbedecomposedveryslowlyinsedimentsthroughvariousreactions(Niesl,1 990 ) .Factorsinfluencingthebiodegradationofcompoundsarevarious.Amongthem ,itwasreportedthattheeffectsofnaturalorganicmatters…     

华北地区中强地震前调制地震异常特征

利用调制地震方法对华北地区１９７３年以来发生的２４个ＭＬ≥５．５地震前地震调制比、地震调制比异常面积、调制地震条带和调制地震频度的异常变化进行分析,对异常类型进行分类。分析结果认为,华北地区ＭＬ≥５．５地震前地震调制比和异常面积随时间进程的起伏、调制地震频度震前数月的突然增大以及调制地震条带异常图象是显著的异常变化,可以用于对中、强地震的中期预报