Cadmium accumulation, activities of antioxidant enzymes, and malondialdehyde (MDA) content in Pistia stratiotes L.

The aquatic plant Pistia stratiotes L. (water lettuce) was studied due to its capability of absorption of contaminants in water and its subsequent use in wetlands constructed for wastewater treatment. The effects of Cd on root growth, accumulation of Cd, antioxidant enzymes, and malondialdehyde (MDA) content in P. stratiotes were investigated. The results indicated that P. stratiotes has considerable ability to accumulate Cd. Cadmium induced higher superoxide dismutase (SOD) and peroxidase (POD) activities than catalase activity, suggesting that SOD and POD provided a better defense mechanism against Cd-induced oxidative damage. The accumulation of Cd promoted MDA production.     

总量控制目标分解计算有关问题的探讨

对总量控制目标分析计算的有关问题进行了讨论，如预留发展量，预留改善量的概念及规划方法，点源总量控制指标的分析计算方法等。分解计算分“一步到位法”和“两步到位法 ”两种方式，诸地有所区别。     

流化吸附法净化处理沥青烟气的研究

以炉灰渣为吸附剂，在流化状态下吸附净化沥青烟气的实验室小试表明，炉灰渣的吸附容量高达１８５ｍｇ／ｇ，一次性净化效率为９９％。该工艺具有运转成本低．操作简单和以废治废的特点，为治理沥青烟气污染提供一条新途径。     

固定化微生物柱对染料废水的脱色试验

以凹凸棒粘土颗粒为载体,混合固定化筛选出的７株高效脱色菌,组装成固定化微生物反应柱。该生物柱对各种染料废水均有良好的脱色作用,在染料为唯一碳源和能源时,对６０ｍｇ／Ｌ的混合染料６ｈ能脱色９１％,对于用染槽废液与食堂废水配制的实际废水,能在７２ｈ的连续流动态下,保持８０％以上的脱色率。固定化微生物柱的脱色机理是凹凸棒颗粒对染料的吸附和细菌对染料的降解的双重作用。     

Characteristics of phosphorus chemistry and its geographical distribution in the Haihe River valley,North China

ＣｈａｒａｃｔｅｒｉｓｔｉｃｓｏｆｐｈｏｓｐｈｏｒｕｓｃｈｅｍｉｓｔｒｙａｎｄｉｔｓｇｅｏｇｒａｐｈｉｃａｌｄｉｓｔｒｉｂｕｔｉｏｎｉｎｔｈｅＨａｉｈｅＲｉｖｅｒｖａｌｌｅｙ，ＮｏｒｔｈＣｈｉｎａＪｉａｎｇＧａｏｍｉｎｇ；ＨｕａｎｇＹｉｎｘｉａｏ；Ｌ...     

Comparing dark- and photo-Fenton-like degradation of emerging pollutant over photo-switchable Bi2WO6/CuFe2O4: Investigation on dominant reactive oxidation species

The extensive use of tetracycline hydrochloride (TCH) poses a threat to human health and the aquatic environment. Here, magnetic p-n Bi₂WO₆/CuFe₂O₄ catalyst was fabricated to efficiently remove TCH. The obtained Bi₂WO₆/CuFe₂O₄ exhibited 92.1% TCH degradation efficiency and 50.7% and 35.1% mineralization performance for TCH and raw secondary effluent from a wastewater treatment plant in a photo-Fenton-like system, respectively. The remarkable performance was attributed to the fact that photogenerated electrons accelerated the Fe(III)/Fe(II) and Cu(II)/Cu(I) conversion for the Fenton-like reaction between Fe(II)/Cu(I) and H₂O₂, thereby generating abundant ?OH for pollutant oxidation. Various environmental factors including H₂O₂ concentration, initial pH, catalyst dosage, TCH concentration and inorganic ions were explored. The reactive oxidation species (ROS) quenching results and electron spin resonance (ESR) spectra confirmed that ?O₂^? and ?OH were responsible for the dark and photo-Fenton-like systems, respectively. The degradation mechanisms and pathways of TCH were proposed, and the toxicity of products was evaluated. This work contributes a highly efficient and environmentally friendly catalyst and provides a clear mechanistic explanation for the removal of antibiotic pollutants in environmental remediation.     

悬浮膜(CFM)分离技术在油田废水处理中的应用

应用微电解等技术对油田废水进行预处理,然后用悬浮膜进行分离,使其中的油、微生物和固体物与水相分离,使其达到回注用水要求。重点对CFM分离设备的结构及原理加以介绍,以期推进过滤技术的进步,提高油田废水的处理水平。     

清水江流域环境保护污染治理经济效益分析

以《贵州省清水江流域环境保护规划(2013-2020年)》为例,分析清水江流域治理主要污染物的削减量和费用支出。从环境经济角度,通过费用-效益分析法以货币量化进行计算,流域治理能带来一定的经济效益、环境效益和社会效益。     

重金属抗性解磷细菌的磷溶解特性研究

从湖南省湘西州花垣县的铅锌矿表层土壤中,筛选出两株具有重金属抗性和解磷特性的细菌T PSB1和T PSB2.通过16S rRNA基因序列比对,分别鉴定为嗜麦芽寡养单胞菌(Stenotrophomonas maltophilia)和唐菖蒲伯克霍尔德菌(Burkholderia gladioli).T PSB1和T PSB2在含有难溶性无机磷液体培养基中,其上清液的可溶性磷含量最高分别达到了402.9 mg·L-1和589.9 mg·L-1;在难溶性有机磷固体和液体培养基中,固体平板上均出现解磷圈,而液体培养基上清液中,可溶性磷含量也分别达到了2.97 mg·L-1和4.69 mg·L-1.另外,两株细菌对重金属Zn2+的抗性最高,在其浓度为2000 mg·L-1固体和液体培养基条件下均可以生长,磷溶解浓度分别为114.8 mg·L-1和125.1 mg·L-1.而在含铬和铅的浓度为1 000 mg·L-1的液体培养基中,两株细菌同样表现出重金属抗性.在Pb2+浓度为1000 mg·L-1的液体培养基中,磷溶解浓度分别达到了57.9 mg·L-1和71.7 mg·L-1;而在Cr2+浓度为1000 mg·L-1的培养基中磷溶解浓度分别为60.1 mg·L-1和98.4 mg·L-1.     

上海中心城区土地利用变化对区域降雨径流的影响研究

土地利用变化导致的城市下垫面改变对降雨径流关系有着重要影响。选择高度城市化的上海中心城区,利用初损和径流量修正方法并经实测数据验证后的SCS-CN修正模型,在城市集水区尺度上,初步探讨模拟了1947—2006年中心城区在0.5～10 a一遇设计暴雨重现期条件下持续1 h的降雨事件和丰、平、枯降雨年份下的径流系数,并分析了土地利用方式、前期土壤湿润程度(AMC)和降雨因素对中心城区60 a降雨径流关系的影响。结果表明:①60 a间,AMCⅠ和0.5～10 a一遇设计暴雨重现期条件下的径流系数相对增长17.21%～6.14%,枯、平和丰水年的年径流系数相对增长分别为20.49%、11.83%和10.02%;②土地利用类型、土壤入渗能力和AMC类型,与降雨强度共同构成影响降雨径流关系的两方面重要因素。随着降雨强度的增大,在AMCⅠ→Ⅲ过程中,土地利用改变对降雨径流关系的影响趋小,降雨类型起决定作用;而降雨强度越小,土壤AMC越干燥,土地利用改变对降雨径流关系影响越强;③不同降雨强度和降水年条件下的径流系数均随CN值的增大而增加,其径流系数与CN值之间分别可用线性(R20.999)和指数(R20.987)关系表示。