非平衡态等离子体技术在环境保护领域的应用

非平衡态等离子体的特点在于通过放电产生的电子温度远远高于系统中其他重粒子的温度。根据这一特点研究了非平衡态等离子体对环境污染物的处理技术;分析了非平衡态等离子与环境污染物的作用过程及其机理;最后探讨了该技术在环境保护领域的应用前景及其存在的问题。      

外来污染物对土壤磷酸酶影响的研究进展

磷酸酶在磷循环中占有重要地位 ,对植物有着非常重要的意义。根据几十年的国内外资料 ,本文概述了重金属、农药、酸沉降以及其他各种外来污染物对土壤磷酸酶的影响 ,并探讨了磷酸酶作为表征土壤污染程度的指标的可行性。土壤磷酸酶与各种污染物的相互作用关系在环境中的应用方面还需进一步研究。     

外加有机碳源对 NO硝化去除的影响

以亚硝酸钠为唯一氮源,研究了摇床上不同外加有机碳源对NO硝化去除的影响程度,以及两种溶解氧状态下有机碳源浓度对NO硝化去除的影响规律。在此基础上初步探讨了有机碳源对NO硝化作用的影响机理。研究结果表明：葡萄糖作为外加有机碳源对NO硝化去除的影响最大。在溶解氧充分条件下（DO≥2mg／L）,外加低浓度葡萄糖（≤20mg／L）,NO硝化去除率保持在90％以上,外加高浓度葡萄糖（≥100mg/L）,异养菌的氧化作用和自养菌的硝化作用可以同时发生作用;低溶解氧条件下（DO≤2mg/L）,由于异养菌生长优先利用了有限的氧,使硝化菌生长受到了抑制,在局部厌氧区域发生了反硝化作用。     

Ecological Responses to Trout Habitat Rehabilitation in a Northern Michigan Stream

Monitoring of stream restoration projects is often limited and success often focuses on a single taxon (e.g., salmonids), even though other aspects of stream structure and function may also respond to restoration activities. The Ottawa National Forest (ONF), Michigan, conducted a site-specific trout habitat improvement to enhance the trout fishery in Cook’s Run, a 3^rd-order stream that the ONF determined was negatively affected by past logging. Our objectives were to determine if the habitat improvement increased trout abundances and enhanced other ecological variables (overall habitat quality, organic matter retention, seston concentration, periphyton abundance, sediment organic matter content, and macroinvertebrate abundance and diversity) following rehabilitation. The addition of skybooms (underbank cover structures) and k-dams (pool-creating structures) increased the relative abundance of harvestable trout (>25 cm in total length) as intended but not overall trout abundances. Both rehabilitation techniques also increased maximum channel depth and organic matter retention, but only k-dams increased overall habitat quality. Neither approach significantly affected other ecological variables. The modest ecological response to this habitat improvement likely occurred because the system was not severely degraded beforehand, and thus small, local changes in habitat did not measurably affect most physical and ecological variables measured. However, increases in habitat volume and in organic matter retention may enhance stream biota in the long term.     

Anaerobic whey treatment by a stirred sequencing batch reactor (ASBR): effects of organic loading and supplemented alkalinity

An assessment was made of cheese whey treatment in a mechanically stirred anaerobic sequencing batch reactor (ASBR) containing granular biomass. The effect of increasing organic load and decreasing influent alkalinity supplementation (as sodium bicarbonate) was analyzed. The reactor operated on 8-h cycles with influent COD concentrations of 500, 1000, 2000 and 4000 mg/L, corresponding to volumetric organic loads of 0.6 to 4.8 mgCOD/L.d. Organic COD removal efficiencies were always above 90% for filtered samples. These results were obtained with an optimized alkalinity supplementation of 50% (ratio between mass of NaHCO3 added and mass of influent mgNaHCO3/mgCOD) in the assays with 500 and 1000 mgCOD/L and of 25% in the assays with 2000 and 4000 mgCOD/L. Initial alkalinity supplementation was equal to the mass of influent COD (100%). The system showed formation of viscous polymer-like substances. These were probably of microbiological origin occurring mainly at influent CODs of 2000 and 4000 mg/L and caused some biomass flotation. This could, however be controlled to enable efficient and stable reactor operation.     

快速固相萃取法测定食品中多种有机磷农药残留

报道了一种简便、快速的石墨碳固相萃取(SPE)食品中多种有机磷农药残留及测定的方法.采用丙酮浸泡、超声提取食品中的有机磷农药,经石墨碳固相小柱净化萃取后,用气相色谱-火焰光度检测法直接测定,加标回收率在72.0%～107%之间,RSD为6.2%～12.7%,最低检出限可达0.001 mg/kg.     

Risk Assessment of Physico-Chemical Contaminants in Groundwater of Pettavaithalai Area, Tiruchirappalli, Tamilnadu – India

A study was carried out in Pettavaithalai area to evaluate the current status of physico-chemical contaminants and their sources in groundwater. Groundwater samples collected from pettavaithalai area in 15 different stations were analyzed every alternative months over a period of two years from August 2000 to June 2002. A sugar mill is situated at the heart of the study area. Three profiles (profile A, B and C) were selected based on the direction in which the sugar mill effluent flows. In each profile five samples were collected from five different station at a regular distance of about 1 Km. The physico-chemical parameters such as pH, EC TDS, TH, NO₃, SO₄, PO₄, Na, K, Ca, Mg, DO, BOD and COD have been analyzed. The results showed that among the three profiles, many of the estimated physico-chemical parameters of profile C were very high when compared to profile B and A which indicates the poor quality of the groundwater around this area.     

柴油机铸造工艺环境污染物的分析

采用Gc／ITD(色谱／离子阱)对铸造车间周围的大气、气溶胶粒子以及制模砂芯浸出物中有机组分作了定性、定量分析,并采用串列式净化装置对烘模窑烟气进行了治理,测试结果表明,治理效果良好。      

Migration of heavy metals in soil as influenced by compost amendments

Soils contaminated with heavy metals can pose a major risk to freshwaters and food chains. In this study, the success of organic and inorganic intervention strategies to alleviate toxicity in a highly acidic soil heavily contaminated with As, Cu, Pb, and Zn was evaluated over 112 d in a mesocosm trial. Amelioration of metal toxicity was assessed by measuring changes in soil solution chemistry, metal leaching, plant growth, and foliar metal accumulation. Either green waste- or MSW-derived composts increased plant yield and rooting depth, reduced plant metal uptake, and raised the pH and nutrient status of the soil. We conclude that composts are well suited for promoting the re-vegetation of contaminated sites; however, care must be taken to ensure that very short-term leaching pulses of heavy metals induced by compost amendment are not of sufficient magnitude to cause contamination of the wider environment.     

Endophytic bacteria improve phytoremediation of Ni and TCE co-contamination

The aim of this work was to investigate if engineered endophytes can improve phytoremediation of co-contaminations by organic pollutants and toxic metals. As a model system, yellow lupine was inoculated with the endophyte Burkholderia cepacia VM1468 possessing (a) the pTOM-Bu61 plasmid, coding for constitutive trichloroethylene (TCE) degradation, and (b) the ncc-nre Ni resistance/sequestration system. Plants were exposed to Ni and TCE and (a) Ni and TCE phytotoxicity, (b) TCE degradation and evapotranspiration, and (c) Ni concentrations in the roots and shoots were determined. Inoculation with B. cepacia VM1468 resulted in decreased Ni and TCE phytotoxicity, as measured by 30% increased root biomass and up to 50% decreased activities of enzymes involved in anti-oxidative defence in the roots. In addition, TCE evapotranspiration showed a decreasing trend and a 5 times higher Ni uptake was observed after inoculation.