交通噪声的衍射作用对住宅小区的影响

交通噪声对住宅小区的影响分析，除考虑直达声和反射声的影响外，还应加入衍射声场的作用。该文建立了典型住宅区中噪声衰减的完整理论模型，计算分析了交通噪声对建筑群纵深的影响，并对无规则分布的建筑群中声衰减作了定性分析。还以典型建筑群为例，对已知建筑布局下噪声在其中的衰减特征，作了说明和验证。     

Influence of ultrasonication on anaerobic bioconversion of sludge.

The influence of ultrasonication on hydrolysis, acidogenesis, and methanogenesis in anaerobic decomposition of sludge was investigated. The sonicated sludge exhibited prehydrolysis and preacidogenesis effects in the anaerobic decomposition process. First-order hydrolysis rates increased from 0.0384 day(-1) in the control digester to 0.0672 day(-1) in the digester fed, with sludge sonicated at 0.52 W/mL. The sonication appeared to be ineffective in relation to acidogenesis reaction rates, but it provided a better buffering capacity to diminish the adverse effect of acidification. Digesters fed with sonicated sludge demonstrated enhanced methanogenesis over the control unit. Determination by coenzyme F420 verified that sonication is able to promote the growth of methanogenic biomass and facilitate a positive methanogenic microbial development in suppressing the initial methanogenesis limitation. The results suggest that ultrasonication could enhance anaerobic decomposition of sludge, resulting in an accelerated bioconversion, improved organics degradation, improved biogas production, and increased methane content.     

Regional distribution of organochlorinated pesticides in pine needles and its indication for socioeconomic development

The regional distribution of 10 potentially harmful organochlorinated pesticides (OCPs) was investigated in pine needles from 18 sites in six Chinese regions. The OCPs concentrations in six regions were as follows: sigmaHCH (sigmaHCH=alpha-+beta-+gamma-+delta-HCH), 4.7-51.5 ng/g; sigmaDDT (p,p'-DDT+p,p'-DDE+p,p'-DDD), 0.9-30.9 ng/g; hexachlorobenzene (HCB), 1.1-5.3 ng/g; sigmachlordane (cis-chlordane+trans-chlordane), no detected-4.3 ng/g, on dry weight basis. Samples from southeast Chinese area contained the highest concentrations of sigmaHCH, sigmaDDT and sigmachlordane, while the contamination levels of most OCPs in southwest Chinese area were the lowest. The ratios of alpha/gamma-HCH (ranged from 1.7 to 5) were observed to be noticeable increase from north to south China, and the ratio of 1.7 revealed the presence of the recent use of lindane in north Chinese area. The significant decrease of the sum concentrations of alpha-+gamma-HCH from mid-1980s to the present and the strong correlation between alpha-, beta-, gamma-, delta-HCH (r=0.87-0.98, n=18, p<0.05) indicated the main usage of the technical HCH in history in China. The p,p'-DDE/p,p'-DDT ratios of <1 revealed the new input of p,p'-DDT in south, southeast and southwest Chinese areas, which could be partly contributed to the new use of impure dicofol. Economic development will leave its mark in the environment, however, its impact on the input and distribution of OCPs on a regional scale is unknown. We attempted to use the socioeconomic index (gross domestic product (GDP) per capita) to explain the distribution and input of OCPs and found that HCB and sigmaDDT seemed to be linked to the economic development, while no relationship of HCH was observed. DDE% of sigmaDDT also showed a negative correlation with the GDP per capita.     

当前环境行政执法中的难点及其对策

通过在环境行政执法实际上作中遇到的难点问题的分析，提出了解决这些难点的对策和措施。     

生物修复中有机污染物的生物可利用性

论述了土壤和地下水生物修复中有机污染物的生物可利用性。污染物的可利用性对生物修复速率和生物强化效率有重要影响。生物可利用性是指土壤和地下水中的微生物或其胞外酶对有机污染物的可接近性，它受土壤理化性质、污染物和微生物性质、污染接触时问等许多因素的综合影响。污染物的介质吸附、多相分配、老化和形成非水相基质，以及土壤微生物的吸附、过滤和沉降作用降低了污染物的可利用性。促进土壤中污染物和微生物的解吸附，增强非水相基质的溶解，加速土壤污染物与微生物之间的质量传递，可以增强污染物的可利用性和生物降解的速率。施用表面活性剂和电动力学方法可有效地增强污染物的生物可利用性。     

广州郊区农业土壤重金属含量与土壤性质的关系

研究了广州郊区农业土壤性质和土壤中的重金属含量,并对2者的相关关系进行了分析。结果表明:广州郊区农业土壤中壤土占样品总数的70.5%,土壤pH值平均为5.93,土壤有机质平均含量为31 7g·kg-1,土壤阳离子交换量不高,且各区之间变幅较大;Cu、Pb、Zn、Ni、Cd、As和Hg有效态含量在3种土壤中顺序为菜园土>水稻土>赤红壤;土壤重金属和土壤理化性质间的关系复杂,如有效态Cu、Zn、Ni与土壤有机质含量呈极显著相关,Cd与土壤有机质含量和土壤粘粒含量呈极显著相关,As除与有机质含量和粘粒含量有关,与pH、阳离子交换量也有极显著相关关系。     

Kinetics of hexavalent chromium reduction by iron metal

The kinetics of Cr(VI) reduction to Cr(III) by metallic iron (Fe⁰) was studied in batch reactors for a range of reactant concentrations, pH and temperatures. Nearly 86.8% removal efficiency for Cr(VI) was achieved when Fe⁰ concentration was 6 g/L (using commercial iron powder (< 200 mesh) in 120 min). The reduction of hexavalent chromium took place on the surface of the iron particles following pseudo-first order kinetics. The rate of Cr(VI) reduction increased with increasing Fe⁰ addition and temperature but inversely with initial pH. The pseudo-first-order rate coefficients (k _obs) were determined as 0.0024, 0.010, 0.0268 and 0.062 8 min⁻¹ when iron powder dosages were 2, 6, 10 and 14 g/L at 25°C and pH 5.5, respectively. According to the Arrehenius equation, the apparent activation energy of 26.5 kJ/mol and pre-exponential factor of 3 330 min⁻¹ were obtained at the temperature range of 288–308 K. Different Fe⁰ types were compared in this study. The reactivity was in the order starch-stabilized Fe⁰ nanoparticles > Fe⁰ nanoparticles > Fe⁰ powder > Fe⁰ filings. Electrochemical analysis of the reaction process showed that Cr(III) and Fe(III) hydroxides should be the dominant final products.     

浅析脱硫石膏综合利用的技术可行性

电厂实施烟气脱硫后所产出的脱硫石膏得到有效利用是推动各电厂脱硫装置正常运行的前提条件。根据国内外文献调研和部分电厂、建材行业等的实地调研,电厂脱硫石膏可作为天然石膏替代品,用作水泥缓凝剂或用于制作石膏制品、改良土壤、矿井与路基回填等。从技术层面考虑,上述综合利用途径在国内外均有了一定实践经验,存在的技术难点也能得到较好的解决,从而为电厂烟气脱硫的实施提供了支持。     

氨基黑10B的EM脱色研究

研究采用有效微生物(EM)对偶氮染料氨基黑10B进行脱色试验研究.试验结果表明.通过对 EM 茵种的培养务件的筛选试验.得到了活性强的、种类多的复合微生物茵群,其中酵母茵和乳酸茵占70%左右.其它茵种为光合细茵、放线茵以及霉茵等.而且该茵种在敞开静止培养方式、红糖质量浓度为lg/L、氨基黑10B的质量浓度为24mg/L条件下有利于生长.     

SD—MOP整合模型在生态工业园规划中的应用探析

生态工业园作为区域产业生态系统,由产业、人口、资源、经济和生态环境等子系统组成。它的持续发展依赖于各子系统的结构合理、功能完整以及各子系统的协调发展和有效控制。文章结合系统动力学模型和多目标规划方法优点,提出了应用于生态工业园规划的整合模型研究思路。从生态工业系统的整体结构功能模拟优化出发,建立生态工业系统动力学（SD）模型,通过模型的原始运行和灵敏度分析,寻找出对工业园发展影响较大的关键点及与之相应的参变量,以此为核心建立多目标规划（MOP）模型,求解MOP模型获取关键点最优解集。再根据模型的解,针对具体情况设计模拟运行方案,与决策者进行交互,取得系统发展的优化规划方案。该整合模型为生态工业园的规划和宏观调控提供了一个新的研究方法,并可为工业系统的可持续发展提供技术支持。