QUALITY OF WATER AND BOTTOM SEDIMENTS IN THE TRINITY RIVER1

ABSTRACT: Data were developed to determine the quality of water and bottom sediments in the Trinity River, and the mobility of various contaminants when bottom sediments were mixed with the river water under simulated dredging conditions. Thirteen sampling sites were selected. A number of chemical tests including heavy metals and pesticides were conducted on river water, elutriates, and bottom sediments. Statis bioassays using Daphnia magna were conducted on river water and elutriates. Results indicated that the river in the upper reach is grossly polluted due to discharge of waste water effluents from several large treatment plants. High concentrations of nitrogen, phosphorus, organic carbon, COD, heavy metals, and pesticides were found in water and bottom sediments. The concentrations of most of these pollutants exceeded the EPA recommended limits. Elutriation gave no consistent results, perhaps because of release or uptake of contaminants from the sediments. High mortality of D. magna were also recorded in the upper reach of the river. The quality of water and bottom sediments gradually improved in lower reaches.     

城市污水石灰法深度处理工艺中有毒物质的变化规律

分别采用7-乙氧基异酚恶唑酮-脱乙基酶(EROD)活性测定法,重组人激素受体基因的酵母测试和Q67发光菌试验方法,对北京市某生活污水处理厂的进水、二沉出水以及经过石灰法深度处理后的出水中的类二恶英物质、类雌激素物质和急性毒性物质进行了分析.进水中的三类生物毒性效应物质中的急性毒性物质,可通过活性污泥法基本去除,而对类雌激素物质和类二恶英物质的去除率分别为76%和52%.经过石灰沉淀法的深度处理后,可使上述两类物质的总去除率达到95%和68%.出水中的雌激素当量水平与欧洲国家污水处理厂出水水平相当,而类二恶英物质的总浓度低于美国EPA饮用水中二恶英的最大允许浓度.展示了生物毒性测试方法在排水生态风险和工艺评价方面的应用潜力.     

土壤中绿磺隆残留量生物测定方法

用生物测定方法测定了土壤中绿磺隆残留量，建立了绿磺隆浓度（Ｙ）与玉米根长（Ｘ）之间的相关模式：Ｙ＝３０．５６２－３６．３８ＩｎＸ＋１４．８２８（ＩｎＸ）￣２＋２．０４３（ＩｎＸ）￣３．此模式适用于土壤中０．１～４．０μｇ／ｋｇ浓度范围的绿磺隆残留量测定，最低检出量为０．１μｇ／ｋｇ。     

利用多生物学指标评价宝应湖沉积物的环境质量

研究了江苏宝应湖沉积物浸出液对水生生态系统的生产者斜生栅列藻 (Scenedesmusobilquus)、初级消费者大型氵蚤 (Daphniamagna)和高级消费者斑马鱼 (Brachyddaniorerio)的影响。结果表明 ,沉积物浸出液对大型氵蚤和斑马鱼无明显的急性毒性。但与湖水对照相比 ,浸出液对斜生栅列藻的生长有显著促进作用 ,且随浸出液浓度升高 ,对藻类促进作用越大。化学监测结果表明 ,沉积物浸出液中磷浓度明显高于湖水 ,表明沉积物中磷向水体释放 ,可促进湖泊富营养化。     

A biological safety evaluation on reclaimed water reused as scenic water using a bioassay battery

An assessment method based on three toxicity tests (algae growth inhibition, daphnia immobilization and larval fish toxicity) was used to screen the biological safety of reclaimed water which was reused as sole replenishment for scenic water system in a park (SOF Park) in northern China. A total of 24 water samples were collected from six sites of water system in the SOF Park in four different seasons. The results indicated that: (1) the reclaimed water directly discharged from a reclamation treatment plant near the SOF Park as influent of park had relatively low biological safety (all samples were ranked as C or D); (2) the biological safety of reclaimed water was improved greatly with the ecological reclamation treatment processes composing of artificial wetland system and followed oxidation pond system; (3) the biological safety of reclaimed water in the main lake of SOF Park kept at a health status during different seasons (all samples were ranked as A); (4) there was some certain correlation (R² = 0.5737) between the sum of toxicity scores and dissolved organic carbon for the studied water samples. It was concluded that the assessment method was reliable to screen the safety of reclaimed water reused as scenic water, and the reclaimed water with further ecological purification processes such as artificial wetland and oxidation pond system can be safely reused as scenic water in park.     

Ames试验对海产贝类遗传毒性的检测

采用Ames试验结合小白鼠生物学试验对贝类腹泻性贝毒(diarrhetic shellfish poisoning,DSP)的提取物进行了遗传毒性初步研究。结果表明:4份贝类样品不同程度地受到了遗传毒物的污染,7份贝类样品受到腹泻性贝毒污染。同时本文也从实践上证明在我国海洋环境监测开展Ames试验对贝类遗传毒性检测具有极为重要的意义。     

Evaluation of soil microbial toxicity of waste foundry sand for soil-related reuse

The relationship between the chemical con- taminants and soil microbial toxicity of waste foundry sand （WFS） was investigated. Five different types of WFS from typical ferrous, aluminum, and steel foundries in China were examined for total metals, leachable metals, and organic contaminants. The soil microbial toxicity of each WFS was evaluated by measuring the dehydrogenase activity （DHA） of a blended soil and WFS mixture and then comparing it to that of unblended soil. The results show that the five WFSs had very different compositions of metal and organic contaminants and thus exhibited very different levels of soil microbial inhibition when blended with soil. For a given WFS blended with soil in the range of 10wt.%-50wt.% WFS, the DHA decreased almost linearly with increased blending ratio. Furthermore, for a given blending ratio, the WFSs with higher concentrations of metal and organic contaminants exhibited greater microbial toxicity. Correlation analysis shows that the relationship between ecotoxicity and metal and organic contaminants of WFSs can be described by an empirical logarithmic linear model. This model may be used to control WFS blending ratios in soil-related applications based on chemical analysis results to prevent significant inhibition of soil microbial activity.     

Application of standard statistical methods in the analysis of complex data generated from soil bioassays to assess the impacts of agrochemical-containing sludge amendments

The use of sludge as soil amendment is widely encouraged by its high contents in organic matter and plant nutrients. Nevertheless, agrochemicals potentially present in sludge could be harmful to terrestrial ecosystems. The present work aimed to apply standard statistical methods for suitable assessment of the ecotoxicological impacts of sludge amendments on soil, involving the following factors: the type of treated sludge, their application dose, and their contents in agrochemicals. Terrestrial Model Ecosystems were used to assess the effects of sludge amendments on endpoints from different trophic levels of the soil ecosystem, including an in vitro estrogenic bioassay on soil leachates. Here, we show the significant negative effects of the highest dose of sludge in most of the soil bioassays. Thermally dried sludge increased significantly the microbial activity leading to lower contamination of leachates with endocrine disrupting molecules. Agrochemicals contents of sludge have only significant impacts on increasing the delay of germination of plant seeds. Soil bioassays are thus complementary to sludge chemical analysis when the impacts of its application on soil should be assessed: significant negative impacts were related to the intrinsic composition of sludge rather than its agrochemicals contents. We conclude that standard statistical methods are relevant tools for the analysis of complex data generated from this type of experiment.     

Ecotoxicological investigations of extremely acidic mining lakes using bioassays suitable for testing at low pH

In this investigation different bioassays were used to detect the physiological and genotoxic effects of water samples of mining lakes. Especially bioassays with higher plants were used like the duckweed bioassay with Lemna minor, the cress bioassay with Lepidium sativum, the Tradescantia‐micronucleus bioassay and the Arabidopsis bioassay. In addition the algae‐motility bioassay with Euglena gracilis were used. All these bioassays were found to be suitable to investigate mining lake samples of extreme acidic character. Four mining lakes (ML 107, ML 111, ML 117, ML F) were selected. They show equally low pH‐values, but differ in size, age, hydro‐chemical and biological state. The results demonstrated that it is possible to differentiate the mining lakes based on the results of bioassays. Samples of ML 107 and 111 showed significant physiological and genotoxic effects. Water samples of both lakes caused severe damages and decreased growth at the same dilution level in all plant bioassays. ML F causes different effects on bioassays. The highest negative effect was observed on root development of L. sativum. ML 117 did not show any effects on duckweed, algae, Tradescantia or Arabidopsis bioassays. There was only a slight effect on the root development in the cress bioassay.