多元回归在大气环境污染事故预测中的应用

运用多元回归法,通过预测模型的选择、数学模型的建立、基础数据的整理和回归效果的检验,建立环境污染范围与诸条件的关系,达到快速估算的目的,从而形成一种有效的大气环境污染事故范围预测的方法.     

兽药抗生素对生态环境的混合毒性研究进展

抗生素是环境中普遍存在的污染物,畜牧水产养殖是其主要来源之一.环境中可能同时存在多种抗生素残留,因此单一药物的毒性评价难以反映抗生素对生态环境的影响,应探究其混合物的毒性效应.本文在总结大量文献的基础上,介绍了兽用抗生素的残留现状,总结了兽用抗生素对生态环境的混合毒性研究进展,讨论了兽用抗生素残留对土壤生物和水生生物的...     

Soil erosion and non-point source pollution impacts assessment with the aid of multi-temporal remote sensing images

Soil erosion associated with non-point source pollution is viewed as a process of land degradation in many terrestrial environments. Careful monitoring and assessment of land use variations with different temporal and spatial scales would reveal a fluctuating interface, punctuated by changes in rainfall and runoff, movement of people, perturbation from environmental disasters, and shifts in agricultural activities and cropping patterns. The use of multi-temporal remote sensing images in support of environmental modeling analysis in a geographic information system (GIS) environment leading to identification of a variety of long-term interactions between land, resources, and the built environment has been a highly promising approach in recent years. This paper started with a series of supervised land use classifications, using SPOT satellite imagery as a means, in the Kao-Ping River Basin, South Taiwan. Then, it was designed to differentiate the variations of eight land use patterns in the past decade, including orchard, farmland, sugarcane field, forest, grassland, barren, community, and water body. Final accuracy was confirmed based on interpretation of available aerial photographs and global positioning system (GPS) measurements. Finally, a numerical simulation model (General Watershed Loading Function, GWLF) was used to relate soil erosion to non-point source pollution impacts in the coupled land and river water systems. Research findings indicate that while the decadal increase in orchards poses a significant threat to water quality, the continual decrease in forested land exhibits a potential impact on water quality management. Non-point source pollution, contributing to part of the downstream water quality deterioration of the Kao-Ping River system in the last decade, has resulted in an irreversible impact on land integrity from a long-term perspective.     

Integrated Risk Framework for Onsite Wastewater Treatment Systems

Onsite wastewater treatment systems (OWTS) are becoming increasingly important for the treatment and dispersal of effluent in new urbanised developments that are not serviced by centralised wastewater collection and treatment systems. However, the current standards and guidelines adopted by many local authorities for assessing suitable site and soil conditions for OWTS are increasingly coming under scrutiny due to the public health and environmental impacts caused by poorly performing systems, in particular septic tank-soil adsorption systems. In order to achieve sustainable onsite wastewater treatment with minimal impacts on the environment and public health, more appropriate means of assessment are required. This paper highlights an integrated risk based approach for assessing the inherent hazards associated with OWTS in order to manage and mitigate the environmental and public health risks inherent with onsite wastewater treatment. In developing a sound and cohesive integrated risk framework for OWTS, several key issues must be recognised. These include the inclusion of relevant stakeholders throughout framework development, the integration of scientific knowledge, data and analysis with risk assessment and management ideals, and identification of the appropriate performance goals for successful management and mitigation of associated risks. These issues were addressed in the development of the risk framework to provide a generic approach to assessing risk from OWTS. The utilisation of the developed risk framework for achieving more appropriate assessment and management techniques for OWTS is presented in a case study for the Gold Coast region, Queensland State, Australia.     

Effect of Cadmium on Microbial Activity and a Ryegrass Crop in Two Semiarid Soils

Soil pollution with Cd is an environmental problem common in the world, and it is necessary to establish what Cd concentrations in soil could be dangerous to its fertility from toxicity effects and the risk of transference of this element to plants and other organisms of the food chain. In this study, we assessed Cd toxicity on soil microorganisms and plants in two semiarid soils (uncultivated and cultivated). Soil ATP content, dehydrogenase activity, and plant growth were measured in the two soils spiked with concentrations ranging from 3 to 8000 mg Cd/kg soil and incubated for 3 h, 20 days, and 60 days. The Cd concentrations that produced 5%; 10%;, and 50%; inhibition of each of the two soil microbiological parameter studied (ecological dose, ED, values) were calculated using two different mathematical models. Also, the effect of Cd concentration on plant growth of ryegrass (Lolium perenne, L.) was studied in the two soils. The Cd ED values calculated for soil dehydrogenase activity and ATP content were higher in the agricultural soils than in the bare soil. For ATP inhibition, higher ED values were calculated than for dehydrogenase activity inhibition. The average yields of ryegrass were reduced from 5.03 to 3.56 g in abandoned soil and from 4.21 to 1.15 g in agricultural soil with increasing concentrations of Cd in the soil. Plant growth was totally inhibited in abandoned and agricultural soils at Cd concentrations above 2000 and 5000 mg/kg soil, respectively. There was a positive correlation between the concentration of Cd in the plants and the total or DTPA-extractable concentrations of Cd in the soil.     

玄武湖蓝藻水华成因探讨

为了解南京玄武湖蓝藻水华的成因,对玄武湖长期监测资料进行了分析和现场调查。结果表明,玄武湖鲢鳙急剧减少中断了正常的食物链,使浮游植物的牧食压力降低,在东南湖回水的诱因作用下,发生了以微囊藻为优势种群的蓝藻水华。指出,玄武湖蓝藻水华的发生进程表明,东南湖回水可能是蓝藻水华发生的诱因,生态失衡是蓝藻水华发生的主要原因,蓝藻水华的暴发与富营养化程度无显著相关性,其暴发加重了玄武湖富营养化程度。     

大宝山采矿活动对环境的重金属污染调查

调查了大宝山铁铜多金属矿床固体废弃物-水相互作用对环境的重金属污染,结果表明,矿床固体废弃物导致了水、土壤的重金属污染,污染元素主要有Cd、Cu、Pb、Zn等;重金属元素的水迁移强度由大至小顺序为Cr、Cu、Zn、Ni、Cd、As、Pb、Hg;元素的生物吸收系数由大至小顺序为Cd、Zn、Hg、Ni、Cu、Cr、As、Pb,虽然水稻糙米中的重金属含量未超过国家标准,但Cd、Cr两种元素含量已远远超出了植物中毒量的下限值.     

青藏铁路用空气弹簧橡胶胶料耐紫外线老化试验研究

我国正在建设的青藏铁路是世界上海拔最高、线路最长的高原铁路.其气候特点对橡胶制品提出了新的技术要求,为适应在该气候条件下的运用需要,进行了针对空气弹簧胶囊用橡胶的耐紫外线老化试验研究工作,试验表明随着紫外线老化时间的增加,其硬度和300%定伸强度均提高,但拉伸强度和扯断伸长率随着紫外线老化时间的增加而降低;通过与胶料的耐臭氧试验和大气老化试验比较,基本可以认为引起空气弹簧胶囊表面龟裂的主要原因是受力状况、臭氧和大气老化的作用,而紫外线对橡胶的表面龟裂影响作用不大,因此,为提高空气弹簧胶囊的耐老化性能,主要考虑降低橡胶的受力,提高耐臭氧和耐大气老化性能.     

接种白腐真菌堆肥处理含Pb垃圾

选取未污染土壤、家庭厨余、稻草、麸皮加入Pb(NO3)2溶液配成模拟含高浓度Pb垃圾,采用接种白腐菌堆制处理和不接菌堆制处理2种方法分别进行室内模拟堆制.通过监测理化因子(pH、挥发性固体、水溶性有机碳/有机氮、木质素、粗纤维)与生化因子(呼吸量、微生物生物量碳)以及生物毒性分析因子(种子发芽指数、重金属含量)随时间的变化,系统地研究了重金属对垃圾堆肥过程的影响和白腐菌堆肥处理重金属污染垃圾的可行性.结果表明,接种白腐菌处理Pb污染垃圾的堆肥过程能顺利进行,较好地减弱了Pb的迁移性从而降低其生物有效性,降低了堆肥潜在的重金属危害性.此堆肥工艺下,堆肥成品pH为7.9,水溶性C/N达4.01,挥发性固体含量降至36.1%,木质素余量22.4 g,粗纤维余量30.1 g;且堆肥中Pb主要以残留态存在,约为63.38%,水溶交换态Pb含量则降至0%,种子发芽指数高达121%.     

乳化液废水均相催化湿式氧化动力学

在2L高压间歇反应釜中,以高浓度难降解乳化废水为处理对象,研究了温度对铜盐均相湿式氧化的影响和动力学特征.结果表明:升高温度对加快后期反应速度更为有利,催化剂有利于中间产物氧化,在200℃催化活性最高,在进水COD48 400mg/L,反应2h去除率为86.6%;催化剂在不同温度作用下机制有所差别:200℃时3个途径反应速度均加快,中间产物加速氧化更明显;220～240℃时反应向生成中间产物方向偏移,活性降低;通用模型能较好地预测均相催化过程.