Chemical composition of post-harvest biomass burning aerosols in Gwangju, Korea

The main objective of this study was to investigate the chemical characteristics of post-harvest biomass burning aerosols from field burning of barley straw in late spring and rice straw in late fall in rural areas of Korea. A 12-hr integrated intensive sampling of particulate matter (PM) with an aerodynamic diameter less than or equal to 10 microm (PM10) and PM with an aerodynamic diameter less than or equal to 2.5 microm (PM2.5) biomass burning aerosols had been conducted continuously in Gwangju, Korea, during two biomass burning periods: June 4--15, 2001, and October 8--November 14, 2002. The fine and coarse particles of biomass burning aerosols were analyzed for mass and ionic, elemental, and carbonaceous species. The average fine and coarse mass concentrations of biomass burning aerosols were, respectively, 129.6 and 24.2 microg/m3 in June 2001 and 47.1 and 33.2 microg/m3 in October--November 2002. An exceptionally high PM2.5 concentration of 157.8 microg/m3 was observed during biomass burning events under stagnant atmospheric conditions. In the fine mode, chlorine and potassium were unusually rich because of the high content of semi-arid vegetation. Both organic carbon (OC) and elemental carbon increased during the biomass burning periods, with the former exhibiting a higher abundance. PM from the open field burning of agricultural waste has an adverse impact on local air quality and regional climate.     

Lead biosorption and desorption by intact and pretreated spirulina maxima biomass

In order to search for locally available and untried biomaterials in China with high removal capacity of heavy metals from wastewater, the feasibility of Spirulina maxima as biosorbent for lead removal and recovery from aqueous solution was investigated. The lead biosorption was studied by using intact biomass and pretreated biomass of S. maxima. The effects of operational conditions (e.g. pH, contact time, biomass concentration etc.) on lead biosorption were investigated. The biosorption was solution pH dependent and the maximum adsorption was obtained at a solution pH of about 5.5. The adsorption equilibrium was reached in 60 min. The biosorption followed the Freundlich isotherm model. The maximum removal ratios of lead were about 84% in intact biomass and 92% in pretreated biomass. The lead adsorbed could be desorbed effectively by 0.1 M nitric acid, EDTA and hydrochloric acid. The results in this study indicated that pretreated biomass of S. maxima was a promising candidate for removing lead from wastewater.     

鲢鱼放养控制北京城市河湖水华试验研究

介绍了利用鲢鱼控制北京城市河湖水华的试验研究,通过不同放养密度(0、17、51和103 g/m3)的现场围隔试验,对鲢鱼放养对水体水质和浮游生物的影响进行了分析.研究结果表明,鲢鱼放养使有鱼围隔中浮游生物量极低,从而使浮游植物基本不受浮游动物影响,而直接受鱼类影响;同时,中等密度(51 g/m3)的鲢鱼放养使水华蓝藻和微小藻的生长均得到了有效抑制,使藻类生物量最低.     

Millennium-old farm breeding of Chinese softshell turtles (<Emphasis Type="Italic">Pelodiscus</Emphasis> spp.) results in massive erosion of biodiversity

Chinese softshell turtles (Pelodiscus spp.) are widely distributed, ranging from the Amur and Ussuri Rivers in the Russian Far East through the Korean Peninsula, Japan, and eastern, central, and southern China to southern Vietnam. In East and Southeast Asia, Chinese softshell turtles are traditionally exploited for food and have been farm-bred in China since the Spring and Autumn Period, more than 2400 years ago. Currently, the annual production of Pelodiscus amounts to 340,000 t in China alone. Using mitochondrial DNA (2428 bp) and five nuclear loci (3704 bp), we examined broad sampling of wild and farm-bred Pelodiscus to infer genetic and taxonomic differentiation. We discovered four previously unknown mitochondrial lineages, all from China. One lineage from Jiangxi is deeply divergent and sister to the mitochondrial lineage of Pelodiscus axenaria. The nuclear loci supported species status for P. axenaria and the new lineage from Jiangxi. Pelodiscus maackii and P. parviformis, both harboring distinct mitochondrial lineages, were not differentiated from P. sinensis in the studied nuclear markers. The same is true for two new mitochondrial lineages from Zhejiang, China, represented by only one individual each, and another new lineage from Anhui, Guangdong, Jiangxi and Zhejiang, China. However, Vietnamese turtles yielding a mitochondrial lineage clustering within P. sinensis were distinct in nuclear markers, suggesting that these populations could represent another unknown species with introgressed mitochondria. Its species status is also supported by the syntopic occurrence with P. sinensis in northern Vietnam and by morphology. In addition, we confirmed sympatry of P. axenaria and P. parviformis in Guangxi, China, and found evidence for sympatry of P. sinensis and the new putative species from Jiangxi, China. We also discovered evidence for hybridization in turtle farms and for the occurrence of alien lineages in the wild (Zhejiang, China), highlighting the risk of genetic pollution of native stock. In the face of the large-scale breeding of Pelodiscus, we claim that the long-term survival of distinct genetic lineages and species can only be assured when an upscale market segment for pure-bred softshell turtles is established, making the breeding of pure lineages lucrative for turtle farms. Our findings underline that the diversity of Pelodiscus is currently underestimated and threatened by anthropogenic admixture. We recommend mass screening of genetic and morphological variation of Chinese softshell turtles as a first step to understand and preserve their diversity.     

化工物料包装过程静电危害分析

高绝缘化工物料在包装过程中极易带电,以聚酯切片包装为研究对象,对聚酯切片在输送、包装过程物料静电起电机理进行了分析,并对聚酯切片输送包装过程中的包装袋表面电位及物料荷质比进行现场检测,探讨了聚酯切片打包过程中静电危害及预防措施。     

构建污水处理厂现代生产管理模式（TPM）

结合本企业生产运行管理需求,从现有污水处理厂生产管控中存在的问题;生产运营管理模式设计原则及TPM生产管理组织模式的设计,阐述了构建污水处理厂现代生产管理模式的设想。     

电池生产含铅废水处理技术研究

研究针对电池生产废水含铅、含氟、含磷、高酸性的特点,采用物化加生化的混凝气浮-化学反应-曝气生物滤池的处理工艺,去除废水中的氟、铅及部分磷酸盐,同时充分吸收、吸附污水中的污染物,达到降解有机污染物、减少污水中BOD5、COD的含量,从而达到良好的处理效果,最终达标排放。     

二妃山垃圾填埋场地下水环境质量浅析

以武汉市二妃山垃圾填埋场的渗滤液和周边地下水环境质量为研究对象,2007年12月采取垃圾填埋场的渗滤液和周边居民自用水井的地下水进行检测分析和模糊评价。测试目标为pH、总硬度和阴阳离子等。经检测后发现垃圾渗滤液中大部分金属离子含量比较高,部分水井中Fe、Hg、Mn、Pb、NO3离子超过地下水质量标准GB／T14848—1993三级标准,可见垃圾填埋场对周边地下水产生了一定的影响。     

Effects of sterilization treatments on the analysis of TOC in water samples

Decomposition experiments conducted with and without microbial processes are commonly used to study the effects of environmental microorganisms on the degradation of organic pollutants.However,the effects of biological pretreatment (sterilization) on organic matter often have a negative impact on such experiments.Based on the principle of water total organic carbon (TOC) analysis,the effects of physical sterilization treatments on determination of TOC and other water quality parameters were investigated.The results revealed that two conventional physical sterilization treatments,autoclaving and 60 Co γ-radiation sterilization,led to the direct decomposition of some organic pollutants,resulting in remarkable errors in the analysis of TOC in water samples.Furthermore,the extent of the errors varied with the intensity and the duration of sterilization treatments.Accordingly,a novel sterilization method for water samples,0.45 μm micro-filtration coupled with ultraviolet radiation (MCUR),was developed in the present study.The results indicated that the MCUR method was capable of exerting a high bactericidal effect on the water sample while significantly decreasing the negative impact on the analysis of TOC and other water quality parameters.Before and after sterilization treatments,the relative errors of TOC determination could be controlled to lower than 3% for water samples with different categories and concentrations of organic pollutants by using MCUR.     

无污染碘化法提金工艺条件及再生研究

以大兴安岭地区呼玛金矿含银氧化矿为原材料,探讨了碘化提金的工艺条件,并对碘的再生方式进行了研究。研究表明,常温条件下当浸出时间为3 h,液固比为5:1,碘含量达到0.8%,pH值在6~8的范围内时,可以得到较理想的浸金率,此时金的浸出率可达到90%以上。为了降低碘化提金的应用成本,采用锌置换金的方法使碘回收,结果显示,当锌粉的加入量为1 g,置换时间为1 h时,置换率最高,碘可以高效回收利用。