苯酚对蔬菜幼苗生长及氧化酶同工酶的影响

含酚污水是当前世界上危害大,污染范围广的一种工业污染源.未经处理直接排放到市郊农村的工业污水严重污染农业生态环境.一些学者就其对鱼类、小麦的毒性影     

重庆南山酸雨与马尾松衰亡的关系

1985—1986年对重庆南山马尾松林衰亡与酸雨的关系进行了研究。四个月的雨水监测表明南山酸雨况情严重。酸雨频率百分之百,平均pH4.2—4.4,最低pH3.6—4.0。土壤酸化程度较重(pH3.7—4.0)。土壤酸化的主要原因是酸雨的输入。濒死树针叶中锰和钴元素大为减少,与土壤中这两种元素的减少相对应。濒死树针叶中铝大量积累,土壤中活性铝增多和铝钙比增大。初步肯定酸雨是南山马尾松衰亡的重要原因之一。     

Impact of photosynthesis and transpiration on nitrogen removal in constructed wetlands

To determine the impact of photosynthesis and transpiration on nitrogen removal in wetlands, an artificial wetland planted with reeds was constructed to treat highly concentrated domestic wastewater. Under different meteorological and hydraulic conditions, the daily changes of photosynthesis and transpiration of reeds, as well as nitrogen removal efficiency were measured. It was found that net photosynthesis rate per unit leaf area was maintained on a high level (average 19.0 μmol CO₂/(m²·s)) from 10:00 to 14:00 in July 2004 and reached a peak of 21.1 μmol CO₂/(m²·s) when Photon Flux Density was high during the day. Meanwhile, TN and NH₄ ⁺-N removal efficiency rose to 79.6% and 89.6%, respectively—the maximum values observed in the test. Correlation coefficient analysis demonstrated a positive correlation among photon flux density, net photosynthetic rate, transpiration rate, and TN and NH₄ ⁺-N removal efficiency. In contrast, there was a negative correlation between stomatal conductance and TN and NH₄ ⁺-N removal efficiency. Results suggest that the photosynthesis and transpiration of wetland plants have a great impact on nitrogen removal efficiency of wetlands, which can be enhanced by an increase in the photosynthesis and transpiration rate. In addition, the efficiency of water usage by reeds and nitrogen removal efficiency could be affected by the water level in wetlands; a higher level boosts nitrogen removal efficiency. Translated from China Environmental Science, 2006, 26(1): 30–33 [译自: 中国环境科学]     

Treatment and utilization of septic tank effluent using vertical-flow constructed wetlands and vegetable hydroponics

Vertical flow constructed wetlands is a typical ecological sanitation system for sewage treatment.The removal rates COD,BOD5,SS,TN and TP were 60%,80%,74%,49%and 79%,respectively,when septic tank effluent was treated by vertical flow filter.So the concentration of COD and BOD5 in the treated effluent could meet the quality standard for irrigation water.After that the treated effluent was used for hydroponic cultivation of water spinach and romaine lettuce,the removal efficiencies of the whole system for COD, BOD5,SS, TN and Tpwere 71.4%,97.5%,96.9%,86.3%,and 87.4%,respectively.And it could meet the integrated wastewater discharge standard for secondary biological treatment plant.It was found that using treated effluent for hydroponic cultivation of vegetables could reduce the nitrate content in vegetables.The removal rates for total bacteria and coliform index by using vertical flow bed system with cinder substrate were 80%-90% and 85%-96%,respectively.     

紫外诱变优势菌处理含氯废水

采用紫外诱变技术选育高效降解菌，对未诱变菌和６株诱变菌进行含氯废水的降解性能实验。结果表明：紫外诱变的最佳时间是４０ｓ；变异优势菌４＾＃菌株对含氯废水的ＣＯＤＣｒ和ＴＣ１（总氯）的去除率比未诱变优势菌０＾＃菌株分别提高１０％和２０％；变异菌菌株生长速度快，抗有机氯毒性大大提高。     

铁(Ⅲ)-羧酸配合物对水溶性染料的光化学脱色动力学的比较研究

铁-柠檬酸，铁-酒石酸，铁-丁二酸，铁-草酸配合物在高压汞灯（λmax＝313nm，250W）的照射下，能使活性艳红X－3B染料水溶液脱色。染料初始浓度在10mg／L～50mg／L时，染料脱色为动力学一级反应，脱色速率随初始浓度增大而降低。在pH2．0～3．0时铁-柠檬酸，铁-滴石酸，铁-丁二酸的染料溶液脱色效果较佳，在pH4．0时铁-草酸的染料溶液脱色效果最好。铁／羧酸盐配比对染料脱色速率也有影响。     

元谋、牟定地区红土化过程中金的富集机理

在对元谋县猛林沟、牟定县戍街两地红土化剖面的地质特征、次生矿物变化、主要元素及金含量变化进行研究的基础上．探讨了金在红土化剖面上的分布形式和红土化过程中全的活化、迁移及沉淀等的机理。笔者认为,区内保存完整的红土化剖面上存在金的双峰式富集,其中产于铁质硬壳层附近的上部金富集带是由于铁质胶体吸附的结果,而腐泥岩层附近的下部金富集带是由Eh变小、pH变大引起的;氧化还原作用是金活化、迁移、沉淀富集最重要的控制机制。     

季铵盐改性土壤对水中苯酚的吸附及机理研究

采用十六烷基三甲基溴化铵（ＨＤＴＭＡ）对土壤进行了改性。结果表明，改必一时最适温度为５０￣５５℃，最适ＰＨ为中性最适ＨＤＴＭＡ浓度为１％，又考察了ＰＨ、改性土壤用量及振荡时间对吸附效果的影响，通过测定吸附等温线探讨了吸附机理。结果表明，ＰＨ＝３￣１０时，酚捐附去除率基本不变，当ＰＨ〉１０时，吸附效率随ＰＨ增大而提高。随着改性土壤用量的增加和振荡时间的延长。酚的去除率升高。改性土壤对苯酚的等温吸附规     

城市防震减灾对策的探讨

本文通过分析造成城市地震灾害严重的多种因素,从搞好建设工程的抗震设防、加强地震科普知识的宣传教育、推动城市社区地震应急救援志愿队和避难场所的建设四个方面提出了城市防震减灾的对策。     

浅论总量排污收费制度的实施效果

总量排污收费制度克服了原有收费制度的弊端，是我国排污收费制度改革的方向。本文以杭州市实施总量排污收费试点为例，证明了这项新的收费制度在促进企业治理污染，改善环境质量中所产生的作用。