Vegetative Ecological Characteristics of Restored Reed (Phragmites australis) Wetlands in the Yellow River Delta, China

In this study, we compared ecological characteristics of wetland vegetation in a series of restoration projects that were carried out in the wetlands of Yellow River Delta. The investigated characteristics include plant composition structure, species diversity and community similarity in three kinds of Phragmites australis wetlands, i.e. restored P. australis wetlands (R1, R2, R3 and R4: restored in 2002, 2005, 2007 and 2009, respectively), natural P. australis wetland (N) and degraded P. australis wetland (D) to assess the process of wetlands restoration. The coverage of the R1 was 99%, which was similar to natural wetland. Among all studied wetlands, the highest and lowest stem density was observed in R1 and R2, respectively, Plant height and stem diameter show the same trend as N > R2 > R1 > R3 > D > R4. Species diversity of restored P. australis wetlands became closed to natural wetland. Both species richness and Shannon–Wiener index had similar tendency: increased first and then decreased with restored time. The highest species richness and species diversity were observed in R2, while the lowest values of those parameters were found in natural P. australis wetland. Similarity indexes between restored wetlands and natural wetland increased with the restoration time, but they were still less than 50%. The results indicate that the vegetation of P. australis wetlands has experienced a great improvement after several years’ restoration, and it is feasible to restored degraded P. australis wetlands by pouring fresh water into those wetlands in the Yellow River Delta. However, it is notable that costal degraded P. australis wetland in this region may take years to decades to reach the status of natural wetland.     

企业环境责任评价体系及成果应用分析

随着环境保护部近年来众多环保举措的提出,企业的环境责任研究引起了学者和相关政府机构的重视。企业环境责任评价有利于提高企业环保意识和规范企业的环境行为,但目前仍缺乏相关机构对企业环境责任评价体系的独立研究和实践。本文通过对国内外企业环境责任的研究现状进行分析,引入了企业环境责任评价的必要性;在相关概念界定的基础上构建了企业环境责任评价指标体系,最后对评价成果的应用进行了探讨和研究。     

膜生物反应器中同步硝化反硝化机制及影响因子探讨

通过膜生物反应器的连续运行,研究了DO、C/N比、F/M和pH等影响因子对膜生物反应器同步硝化反硝化的影响,并对其影响机制进行了分析。实验结果表明,DO、C/N比、F/M和pH是同步硝化反硝化效果的重要影响因子;膜生物反应器中pH值的变化在7左右,DO为0.8 mg/L,C/N比为10,F/M在0.15~0.36 kg COD/(kg MLSS.d)之间时能发生比较好的同步硝化反硝化现象。     

臭氧氧化法深度处理印染废水二级出水

采用臭氧氧化法深度处理印染废水二级出水,以比臭氧消耗量为基础讨论出水水质的改善情况.实验结果表明:当比臭氧消耗量为6.5 mg/mg 时,出水的吸光度在400 nm处减少90%以上,在254 nm处减少85%以上;出水的溶解性有机碳质量浓度为11.23 mg/L、COD为16.3 mg/L;臭氧分子直接氧化对降低色度和去除有机物起到一定作用,采用臭氧氧化法深度处理印染废水二级出水在技术上是可行的.     

一株耐铬不动杆菌对十二烷基硫酸钠的降解特性

研究醋酸钙不动杆菌H1的降解广谱性时,发现其能在高浓度十二烷基硫酸钠(SDS)环境中生长。经过对菌株H1降解特性研究,结果表明,该菌利用SDS的最适温度为30℃,最适pH为7.0,最适接种量为2%,并适应低渗透压环境。当SDS浓度低于400 mg/L时,菌株H1对SDS的降解率在85%以上,且在SDS浓度为400 mg/L时,达到最大降解率94%。当K2Cr2O7为500 mg/L时,菌株H1对SDS的降解率仍达到50%左右。添加酵母浸出物可促进SDS的降解。     

不同添加剂下污泥堆肥化处理氮素变化研究

研究采用了高温好氧堆肥的方法,将城市生活污泥与不同比例花生壳、干污泥混合,在密闭反应器中堆肥,研究堆肥过程中氨气挥发量以及各种形态氮素含量的变化情况。结果表明,初始含水率调整在60%左右,综合堆体温度、含水率下降、氨气挥发量及氮素转化损失量,在污泥处理中添加8.3%花生壳+41.7%干污泥的处理效果最佳,其单位时间氨气挥发量为对照处理的1/5,全氮损失8.9%。在实际生产中,可以将堆肥产物干污泥循环使用,再辅以少量花生壳等干物料进行污泥堆肥,可达到降低成本的效果。     

温度对SBR单级好氧生物除磷性能的影响

以合成废水为研究对象,以丙酸钠作为单一碳源,分别设置温度为5、15、25、35℃的4组序批式反应器(R1、R2、R3、R4),考察了温度对单级好氧工艺除磷的影响。结果表明,稳定运行阶段,R1、R2、R3、R4出水磷浓度分别为4.05、2.17、1.34和0.11 mg/L,去除效率分别为61.5%、79.3%、87.2%和99.0%,吸磷速率分别为0.501、1.432、2.538和3.700mg P/(g VSS·h),即提高温度有利于磷的去除。此外,各反应器中多聚磷酸盐激酶(PPK)和外切磷酸盐酶(PPX)活性分别为0.093、0.213、0.376、0.549 U和0.010、0.019、0.029、0.025 U,导致吸磷速率和释磷速率随之增大,可知温度影响聚磷菌PPK和PPX的活性,从而影响除磷效果。静置阶段,聚磷菌体内储能物质糖原质和聚羟基脂肪酸酯基本保持不变,但各反应器均出现了释磷现象,聚磷作为主要供能物质,单位释磷量分别为1.95、6.42、9.90和9.56 mg P/(g TSS),提高温度可促进静置段聚磷分解提供能量,从而驱动好氧吸磷达到更好的除磷效果。     

固定化生物活性炭处理低浓度甲醇废水

将分离筛选得到的甲醇降解菌固定在颗粒活性炭上,组成固定化生物活性炭反应系统,研究该反应系统处理轻度污染含甲醇废水的最佳运行条件和运行效果,结果表明,固定化生物活性炭处理轻度污染含甲醇放心水的方法明显好于3种树脂和单纯活性炭吸附处理,反应系统的最佳运行条件是水力负荷0．84－0．77m^3(m^2.h）,停留时间57－62min,pH7－8,温度20℃－30℃,溶解氧是去除甲醇的主要限制因子,甲醇含量为11．3－23．1mg／L时,去除率大90％,出水CODcr小于12mg／L。此外还研究了生物活性炭生物膜的一些特点,并分析了运行中活性炭吸附性能的变化。