壳聚糖及其衍生物在工业废水处理中的应用研究进展

壳聚糖是一种对环境友好同时具有多种特性的天然高分子聚合物。以壳聚糖及其衍生物处理工业废水,安全无毒、可生物降解、无二次污染。对国内外近年来壳聚糖及其衍生物在印染、电镀、食品加工、造纸等工业废水处理方面的研究和应用进展进行了扼要的综述。     

我国灾害信息传播的研究现状与展望

近年来灾害事件频发,有关灾害信息传播的研究成为传播学的一个热点研究方向,目前我国灾害信息传播的研究角度众多,取得了较为丰硕的成果,但大多还只停留在个案研究层面,系统研究有待加强。本文在分析现状的基础上,提出了整合传播是我国灾害信息传播研究的新方向,并可分出传播渠道整合、传播内容整合和传媒自身整合等众多研究分支。     

Particulate matter and metals partitioning in highway rainfall-runoff

This study investigated the particulate matter (PM) and metals in highway dry deposition and rainfall-runoff as a function of hydrologic transport and settling on an event basis. Events were differentiated as mass-limited (ML) and flow-limited (FL). Results indicate that unique and separate suspended sediment concentration (SSC) relationships with turbidity occurred for ML and FL events. Sixty minutes of quiescent settling produced a single SSC-turbidity relationship for all events. ML events transport higher proportions of settleable and sediment PM while FL events transported relatively higher suspended PM. For batch clarification with one hour of settling, ML events had generally higher treatment efficiencies compared to FL events for the same settling conditions. Highway dry deposition PM was hetero-disperse and coarse (d _{50 m} = 304 μm). Results indicate that the acidic rainfall is not a significant contributor to metals in runoff but is capable of leaching metals from dry deposition PM into runoff. Partitioning in retained runoff resulted in a particulate-bound predominance for most metals except Ca and Mg. While the finer fraction of dry deposition PM (< 75 μm) generates the highest metal concentrations, the highest metal mass is associated with the coarser fraction (> 75 μm).     

A bioaugmentation failure caused by phage infection and weak biofilm formation ability

Two biological aerated filters (BAF) were setup for ammonia removal treatment of the circulation water in a marine aquaculture. One of the BAFs was bioaugmented with a heterotrophic nitrifying bacterium, Lutimonas sp. H10, where the ammonia removal was not improved and the massive inoculation was even followed by a nitrification breakdown from day 9 to 18. The nitrification was remained stable in control BAF operated under the same conditions. Fluorescent in situ hybridization (FISH) with rRNA-targeted probes and cultivable method revealed that Lutimonas sp. H10 almost disappeared from the bioaugomented BAF within 3 d, and this was mainly due to the infection of a specific phage as revealed by flask experiment, plaque assay and transmission electron observation. Analyses of 16S rRNA gene libraries showed that bacterial groups from two reactors evolved di erently and an overgrowth of protozoa was observed in the bioaugmented BAF. Therefore, phage infection and poor biofilm forming ability of the inoculated strain are the main reasons for bioaugmentation failure. In addition, grazing by protozoa of the bacteria might be the reason for the nitrification breakdown in bioaugmented BAF during day 9–18.     

Combined toxicity of copper and cadmium to six rice genotypes （Oryza sativa L.）

Accumulation of copper (Cu) and cadmium (Cd) in six rice cultivars (94D-22, 94D-54, 94D-64, Gui630, YY-1 and KY1360) was evaluated through exposure to heavy metal contamination (100 mg/kg Cu, 1.0 mg/kg Cd, and 100 mg/kg Cu + 1.0 mg/kg Cd) in a greenhouse. The dry weight of shoot and root, concentrations of Cu and Cd in plant tissues and the Cu, Cd, P, Fe concentrations in the root surface iron plaques were analyzed eight weeks later after treatment. The results indicated that the plant biomass was mainly determined by rice genotypes, not Cu and Cd content in soil. Separated treatment with Cu/Cd increased each metal level in shoot, root and iron plaques. Soil Cu enhanced Cd accumulation in tissues. In contrast, Cu concentrations in shoot and root was unaffected by soil Cd. Compared to single metal contamination, combined treatment increased Cd content by 110.6%, 77.0% and 45.2% in shoot, and by 112.7%, 51.2% and 18.4% in root for Gui630, YY-1 and KY1360, respectively. The content level of Cu or Cd in root surface iron plaques was not affected by their soil content. Cu promoted Fe accumulation in iron plaques, while Cd has no effect on P and Fe accumulation in it. The translocation of Cu and Cd from iron plaques to root and shoot was also discussed. These results might be beneficial in selecting cultivars with low heavy metal accumulation and designing strategies for soil bioremediation.     

磷矿山清洁生产评价指标体系的构建——以贵阳市磷矿山为例

通过对磷矿山清洁生产评价指标选取原则和筛选方法的确定。并结合磷矿山的实际情况,经过多次专家咨询,从而筛选出适合磷矿山清洁生产的具体评价指标。并按层次分析法（AHP）的特点确定目标层、准则层、指标层、指标因子层四个层次,其中,目标层有1项;准则层有6项;指标层有28项;指标因子层有9项,最后建立磷矿山清洁生产评价指标体系,这将为磷矿采选业清洁生产评价提供技术支持和导向,从而有助于磷矿企业推行清洁生产技术,实现可持续发展。     

污水管道中硫循环三阶段模型研究综述

污水在管道输送的过程中很容易出现厌氧环境,产生的硫化氢常引起恶臭、中毒和腐蚀等一系列问题。这些问题可归结为因硫元素在管道中不同相态间的迁移转化所致,该过程主要包括三个阶段：污水中硫化物的产生和扩散、硫化氢由液相到气相的逸散以及管壁上硫化氢的氧化进而引起混凝土等管道腐蚀。对这三阶段机理模型进行了归纳总结,最后在三阶段模型的基础上阐述了控制和预防硫化氢问题的方法,从而为污水输送系统的运行、管理和设计提供参考。     

电子垃圾中铅污染及对策研究

伴随着电子信息等高科技产业的快速发展,电子垃圾已成为增长速度最快的固体废弃物。电子垃圾成分复杂且其污染物众多,尤其是其中的铅污染对环境与健康的影响越来越受到人们的关注,对电子垃圾的不恰当处理势必造成了严重的环境污染。本文调研分析了中国电子垃圾中铅元素污染的现状,探讨了铅污染的原因及其防治对策,并对各种对策的可操作性进行了评价。另一方面,借鉴国外先进经验,对中国电子垃圾中铅元素的污染防治提出了建议。     

融入循环经济体系的滨海湿地资源开发思路探讨

滨海湿地是湿地的重要类型之一,其资源、生态、旅游、文化、教育、科研等多方面的潜在功能对社会、经济发展均有极其重要的作用。而中国滨海湿地遭受破坏的情况较为严重。当前,如何基于科学发展观,将滨海湿地纳入循环经济系统之中,更加合理地进行开发、保护,已成为关系到中国经济可持续发展的重要问题之一。文章基于对山东滨州地区典型滨海湿地资源开发实践的研究,结合中国其他地区湿地开发保护的经验教训,以循环经济理论为指导进而探讨适合中国国情的滨海湿地资源开发思路、模式,并在此基础上提出一些建议,以期能够对中国“十一五”时期的湿地开发、保护工作以及部分地区区域经济发展起到一定借鉴、推进作用。     

唐山市区大气环境中氮氧化物的监测与分析

通过使用分光光度法测定大气中氮氧化物浓度,采集样品分析得出唐山市西道大气中氮氧化物污染现状,了解大气中氮氧化物污染水平。由实验数据分析可知,路段中间的监测点的氮氧化物日小时均值浓度大约为0．037mg／m^3,氮氧化物浓度值受风力影响大于车流量的影响,路口监测点由于车流量大,其氮氧化物浓度值也对应升高,大约为0.046mg/m^3,其受车流量的影响大于风力影响,说明当车流量超过一定值时,风力的影响就会战弱。结果表明,唐山市新华西道氮氧化物日均值浓度大于0.05mg／m^3,氮氧化物污染指标的平均值均超过国家环境空气质量二级标准。因此,此道路属于污染区。还提出了减轻氮氧化物污染状况的几点建议。