Oxidation of As(Ⅲ) by potassium permanganate

The oxidation of As(Ⅲ) with potassium permanganate was studied under conditions including pH, initial As(Ⅲ) concentration and dosage of Mn(Ⅶ). The results have shown that potassium permanganate was an effective agent for oxidizing of As(Ⅲ) in a wide pH range. The pH value of tested water was not a significant factor affecting the oxidation of As(Ⅲ) by Mn(Ⅶ). Although theoretical redox analyses suggest that Mn(Ⅶ) should have better performance in oxidization of As(Ⅲ) within lower pH ranges, the experimental results show that the oxidation efficiencies of As(Ⅲ) under basic and acidic conditions were similar, which may be due to the adsorption of As(Ⅲ) on the Mn(OH)2 and MnO2 resulting from the oxidation of As(Ⅲ).     

农村水环境问题及治理对策

本文通过对农村地区水环境现状的分析,指出农村水环境存在问题,如水土流失,旱涝灾害对水环境的污染等问题,同时提出了保护农村水环境、改善农村水环境的主要措施.提出了各级政府应重视农村水污染的治理、积极改善农村的水环境.     

滇池蓝藻成份分析及利用途径探讨

滇池蓝藻的粗蛋白为４３．６９％，藻蓝蛋白为８－１５％，藻多糖为５￣８％。初步估算，滇池每年可收获的蓝藻的生物量约１００００吨鲜重，其中可用于资源化的量约为５０００吨（干重）左右。一吨蓝藻干粉可以生产藻蓝蛋白５０－８０ｋｇ，藻多糖２０ｋｇ，藻毒素１ｋｇ；同时还可与其他原料混合制成饲料或肥料在农业上应用。     

战略环境评价指标体系框架研究——以流域规划为例

《规划环境影响评价技术导则》（试行）对规划环境影响评价的实践给出了指导,但作为规划环境评价对象之一的流域规划,该导则目前还没有给出其环境影响评价的指标体系。依照DPSIR框架的思路,初步建立了流域规划环境影响评价指标集。但DPSIR框架也不是很完善,因其对因果关系简化过多,难以了解复杂的现实因果关系,所以要达到真实的综合环境评价,需要对现实指标的关系进行深入的研究,需要改进DPSIR思路。     

钢铁行业污染物排放标准执行过程中应注意的几点问题研究

对2012年钢铁行业污染物排放系列新标准颁布以来,在执行过程中遇到的实际问题进行了总结.结合工作实践,对新标准污染物限值排放趋严带来的达标排放监管压力、标准适用范围容易发生混淆的几类情形、以及现场监测布点时存在的操作困难等问题进行了分析,并提出了相应的解决方法和改进建议.为更好地执行钢铁行业新标准,加强钢铁企业污染源监测、环境管理、监督执法,以及标准日后修订、出台配套政策等提供了决策参考.     

略论中医学防治环境污染疾病的优势

本文说明了古代中医对环境污染并非一无所知.认为现代中医学应将环境污染作为一项病因提到教学与研究的日程.探讨了环境污染性病因的概念及其致病特点.简论了中医学防治环境污染疾病的认识论和实践性的优势.坚信中医学在此领域将大有作为.     

鲢鳙放养水平对淀山湖浮游植物群落影响的围隔实验

在淀山湖进行放养不同密度鲢、鳙的围隔实验（密度水平梯度设置为0、40、80和120 g/m3）,探索鲢、鳙的现场控藻效果。结果表明,实验后期（8—9月）,鲢、鳙放养密度为80 g/m3和120 g/m3的围隔对叶绿素a的去除效果显著（P〈0.05）;且放养密度为80 g/m3的围隔蓝藻比例降幅最明显。鲢、鳙对较大个体藻...     

河蚬对太湖梅梁湾沉积物中HCHs和DDTs的生物富集

以采自清洁水体的河蚬(Corbicula fluminea)为实验生物,利用生物富集实验测试了河蚬对太湖梅梁湾水源地沉积物中HCHs和DDTs的生物富集.研究结果表明,将河蚬暴露于有机氯农药污染程度相似的太湖梅梁湾沉积物中(HCHs和DDTs浓度分别为1.5-1.8.S/S(以干重计)和1.1-1.7 as/g(以干重计))后,随着暴露时间的延长(24～168h),河蚬对有机氯农药的富集量随着暴露时间逐渐增加.试验结束时各样点中河蚬对HCHs和DDTs的富集量分别为(9.4±2.2)ng/g(以干重计)、(20.7±7.6)ng/g(以干重计).实验水体沉积物中HCHs和DDTs的生物沉积物富集因子(BSAF)分别为1.5±0.1和4.4±0.7.生物-沉积物富集因子(BSAF)与有机物的辛醇-水比值(Kow)存在显著正相关.     

Enzymological mechanism for the regulation of lanthanum chloride on flavonoid synthesis of soybean seedlings under enhanced ultraviolet-B radiation

In order to probe into the enzymological mechanism for the regulation of lanthanum chloride (LaCl₃) on flavonoid synthesis in plants under enhanced ultraviolet-B (UV-B) radiation, the effects of LaCl₃ (20 and 60 mg l^?1) on the content of flavonoids as well as the activities of phenylalanine ammonia-lyase (PAL), cinnamate-4-hydroxylase (C4H), 4-coumarate?:?coenzyme A ligase (4CL), and chalcone synthase (CHS) in soybean seedlings under enhanced UV-B radiation (2.6 and 6.2 kJ m^?2 day^?1) were investigated. Enhanced UV-B radiation (2.6 and 6.2 kJ m^?2 day^?1) caused the increase in the content of flavonoids as well as the activities of PAL, C4H, 4CL, and CHS in soybean seedlings. The treatment of 20 mg l^?1 LaCl₃ also efficiently increased these indices, which promoted the flavonoid synthesis and provided protective effects for resisting enhanced UV-B radiation. On the contrary, the treatment of 60 mg l^?1 LaCl₃ decreased the content of flavonoids as well as the activities of C4H, 4CL, and CHS in soybean seedlings except increasing the activity of PAL, which were not beneficial to the flavonoid synthesis and provided negative effects for resisting enhanced UV-B radiation. In conclusion, enhanced UV-B radiation caused the increase in the flavonoid synthesis by promoting the activities of PAL, C4H, 4CL, and CHS in soybean seedlings. The treatment of LaCl₃ could change flavonoid synthesis in soybean seedlings under enhanced UV-B radiation by regulating the activities of PAL, C4H, 4CL, and CHS, which is an enzymological mechanism for the regulation of LaCl₃ on flavonoid synthesis in plants under enhanced UV-B radiation.     

Effects of sorption on biodegradation rates of 2,4-D: Improvement of Rao''s model

In the presence of sorbents, the biodegradation rates of organic compounds can be decreased or increased. Four kinds of interactions have to be considered as follows: (1) chemicals in solution reacted with bacteria in solution; (2) sorbed chemicals reacted with bacteria in solution; (3) chemicals in solution reacted with sorbed bacteria and (4) sorbed chemicals reacted with sorbed bacteria. The corresponding rate constants K can be solved in our improved model. Some special situations are discussed.

The biodegradation of 2,4-D, as an example, reacted with a pure strain (Pseudomanos sp.) which was isolated from soil polluted by 2,4-D then labeled by radioactive ³²P were performed in the presence of sediment (or soil). The results showed that 2,4-D sorbed on sediment (or soil) were available to neither bacteria in solution nor bacteria on sediment (or soil), but 2,4-D in solution can be degraded by both bacteria in solution and bacteria on sediment (or soil). Biodegradation of 2,4-D in the presence of sediment (or soil) agreed with results of Rao's model.