场地环境评价在中国的现状及其发展趋势

以中国现有的场地环境评价的标准和法律法规,以及实施现状为基础,参照发达国家和地区的相关经验,阐述在中国实施场地环境评价的必要性和相关标准的制定或修订趋势。在中国广泛推进实施场地环境评价,不仅有利于降低场地变更带来的环境风险,降低场地买卖和商业并购中的投资风险,还有利于加强对土壤和地下水的环境保护。     

硝基苯污染底质的微生物强化修复研究

采用从污染底质中分离出的可降解硝基苯的恶臭假单胞菌,对硝基苯污染底质的微生物强化修复进行了实验室和现场实验研究.该细菌在未灭菌的河水中可以硝基苯为唯一碳源生长,低温条件下(5℃),对于100g的含有11.8mg/kg硝基苯的污染底质,投加2mL(107cells/mL)菌液可以在4d完全降解底质中的硝基苯,实现对污染底质的强化修复.该过程中无须投加额外的氮、磷及其他的营养盐,说明污染底质中含有足够的细菌生长所需的营养物质.在使用河水和底质的现场实验中,当底质和河水中的硝基苯初始浓度在7～8mg/kg,50～61mg/L之间时,投加硝基苯降解菌可使底质和河水中硝基苯的降解时间缩短了40h以上,河水中的硝基苯先于底质中的硝基苯被细菌所降解.     

大学校园土壤中重金属污染研究

为研究大学校园土壤中重金属污染的状况,在西部某高校校园中选取10个采样点,分别采集了表层和下层土样,分析测定了土样中Cu,Zn,Pb,Cr四种重金属的含量。实验采用了微波消解、火焰原子吸收分光光度法对土样进行测定。结果表明待测校园土壤中重金属含量目前处于安全的范围,但大学,尤其是高等科研院校,应妥善处理科研试验过程中产生的污染物,为大学学生提供一个安全的大学校园环境。     

原生颗粒污泥单级自养脱氮工艺处理污泥压滤液的研究

在长期运行的处理污泥压滤液的气提亚硝化反应器中发现了单级自养脱氮反应,并形成了具有自养脱氮性能的原生颗粒污泥.以原生颗粒污泥启动并运行了单级自养脱氮反应器,对污泥压滤液进行脱氮处理取得了良好效果.进水总氮浓度为350 mg.L-1左右时,总氮平均去除率为74.81%,最高达86.92%,总氮平均去除负荷(以N计,下同)为0.68 kg.(m3.d)-1,最高达0.90 kg.(m3.d)-1.投加粉末活性炭后单级自养脱氮反应得到强化,运行稳定性得到提高.进水基质浓度、氮负荷及曝气量对自养脱氮反应影响较大.污泥压滤液中的有机物、pH值和碱度对单级自养脱氮反应影响较小.曝气量/ΔTN、曝气量/ΔNH4+-N及ΔALK/ΔTN比值可作为单级自养脱氮反应重要的运行指标.     

西北冰洋海域表层沉积物中厌氧菌分布特征

用逐步稀释法在4℃和25℃培养条件下测定了西北冰洋海域24个表层沉积物样品中厌氧菌(Anaerobic bacteria,AAB) 的检出率和含量.同时,分析了这两项指标的水平分布（纬度间、经度间）差异,以及在不同水深的变化特征.结果表明,在4℃和25℃培养条件下厌氧菌检出率高达100%,AAB含量范围分别为9.00×102~2.40×107cell·g-1和2.90×104~2.40×107cell·g-1,平均含量分别为4.54×106cell·g-1和3.99×106cell·g-1.AAB含量存在水平分布差异,随着纬度升高,或经度自西向东,或水深的加大,AAB的含量均呈现逐渐降低的趋势.     

Enhanced methane production in an anaerobic digestion and microbial electrolysis cell coupled system with co-cultivation of Geobacter and Methanosarcina

The anaerobic digestion(AD)and microbial electrolysis cell(MEC)coupled system has been proved to be a promising process for biomethane production.In this paper,it was found that by co-cultivating Geobacter with Methanosarcina in an AD–MEC coupled system,methane yield was further increased by 24.1%,achieving to 360.2 m L/g-COD,which was comparable to the theoretical methane yield of an anaerobic digester.With the presence of Geobacter,the maximum chemical oxygen demand(COD)removal rate(216.8 mg COD/(L·hr))and current density(304.3 A/m_3)were both increased by 1.3 and 1.8 fold compared to the previous study without Geobacter,resulting in overall energy efficiency reaching up to 74.6%.Community analysis demonstrated that Geobacter and Methanosarcina could coexist together in the biofilm,and the electrochemical activities of both were confirmed by cyclic voltammetry.Our study observed that the carbon dioxide content in total gas generated from the AD reactor with Geobacter was only half of that generated from the same reactor without Geobacter,suggesting that Methanosarcina may obtain the electron transferred from Geobacter for the reduction of carbon dioxide to methane.Taken together,Geobacter not only can improve the performance of the MEC system,but also can enhance methane production.     

Mg/Al金属氧化物的物化性质及吸附特性

为研究微波煅烧和常规煅烧下的Mg/Al金属氧化物的物化性质、吸附特性及机理,通过XRD(X射线衍射)、SEM(扫描电镜)、BET-BJH(比表面积-孔结构)和pH_ZPC(零电荷点)等表征手段分析了微波煅烧对水滑石结构、形貌、纹理性质及表面电荷性质的影响.结果表明:微波煅烧可获得结晶度更高、片状结构更规整的Mg/Al金属氧化物;微波煅烧使Mg/Al金属氧化物的比表面积由184 m2/g增至205 m2/g,孔容和孔径分别由0.245 cm3/g和2.15 nm增至0.263 cm3/g和2.19 nm;pH_ZPC由12.3增至12.6.微波煅烧和常规煅烧下的Mg/Al金属氧化物的对Cr(Ⅵ)吸附的ΔH(标准焓变)分别为42.86和41.23 kJ/mol,E_a(吸附活化能)分别为21.82和22.59 kJ/mol,二者的吸附过程均为化学吸附且受扩散控制,在该研究条件下的二者理论吸附量最大值分别为93.51和90.31 mg/g,微波煅烧提升了Mg/Al金属氧化物吸附能力,但并不显著;微波煅烧使得Mg/Al金属氧化物更易发生结构还原,其对Cr(Ⅵ)的吸附实质就是结构还原过程.研究显示,微波煅烧并没有改变Mg/Al金属氧化物吸附特性和机理.      

Growth inhibition and oxidative damage of Microcystis aeruginosa induced by crude extract of Sagittaria trifolia tubers

Aquatic macrophytes are considered to be promising in controlling harmful cyanobacterial blooms. In this research, an aqueous extract of Sagittaria trifolia tubers was prepared to study its inhibitory effect on Microcystis aeruginosa in the laboratory. Several physiological indices of M. aeruginosa, in response to the environmental stress, were analyzed. Results showed that S. trifolia tuber aqueous extract significantly inhibited the growth of M. aeruginosa in a concentration-dependent way. The highest inhibition rate reached 90% after 6 day treatment. The Chlorophyll-a concentration of M. aeruginosa cells decreased from 343.1 to314.2 μg/L in the treatment group. The activities of superoxide dismutase and peroxidase and the content of reduced glutathione in M. aeruginosa cells initially increased as a response to the oxidative stress posed by S. trifolia tuber aqueous extract, but then decreased as time prolonged. The lipid peroxidation damage of the cyanobacterial cell membranes was reflected by the malondialdehyde level, which was notably higher in the treatment group compared with the controls. It was concluded that the oxidative damage of M. aeruginosa induced by S.trifolia tuber aqueous extract might be one of the mechanisms for the inhibitory effects.     

废弃物领域协同减排是实现温室气体减排的重要途径

温室气体减排背后巨大的利益博弈成为我国开展减排工作不得不考虑的因素。从国际经验看来,＂避重就轻＂的减排策略成效显著,通过对一些国家和地区温室气体减排路径的比较和分析,结果表明,废弃物领域成为他们减排效果最好的领域之一。废弃物领域协同减排具有空间大、难度小、成本低、效果好、技术成熟、手段多样的优点,应当成为我国实现温室气体减排的重要途径,为经济发展腾出合理的碳排放空间。     

承包商 HSE 管理体系运行存在问题及对策

分析了承包商HSE管理体系的运行现状,针对存在的问题,提出了管理措施。