基于源流域水量水质模型研究小流域营养物管理方案

采用澳大利亚源流域水量水质模型模拟东山小流域内2001-2010年9种不同土地利用类型产生的降雨径流及总氮和总磷的污染负荷,模拟结果为:流域内多年平均径流量为6 150万m3/a,总氮输出负荷为270 t/a,总磷负荷为22 t/a。模拟结果表明:水产养殖塘和高地茶果树是东山地区主要的营养物来源。通过三个情景方案的模拟,说明当地环境管理方案可以有效地削减入湖的营养负荷,其中第二个情景方案的削减量最大,总氮和总磷负荷分别削减了18%和25%。     

长庆油田油气泄漏防治体系建设与应用

为防治油气泄漏事件,长庆油田以重点环境保护目标为对象,按照层级防护、标本兼治、数字预警、分级响应、就地控制的原则,建设油气泄漏防治体系,明确和落实油田公司、厂处、作业区、生产岗位四个层级的防治范围和职责,构建系统参数预警报警、阀门截断、基础防护三道防线,全面提升安全环保的防范能力和水平。保证事故状态下,能够在最短时间、最小范围内进行最有效的处置,实现重点环境保护目标的安全。     

浅析中小城市生态安全格局的构建

双流县是四川省中小城市快速发展的典型代表,面临着快速城市化过程中生态服务功能退化与城市生态安全保障的矛盾。利用RS和GIS技术,对双流县生物多样性保护功能重要性、水源涵养功能重要性、土壤保持功能重要性进行评价分析,并进行综合叠加,构建生态安全格局。同时提出生态安全体系优化建议,加强对区域生态安全具有重要意义区域的保护,协调经济发展与生态环境保护的空间冲突,可为其他地区中小城市生态安全格局构建提供借鉴。     

CaCu3Ti4O12, an efficient catalyst for ibuprofen removal by activation of peroxymonosulfate under visible-light irradiation

Environmental Chemistry Letters - Contamination of waters by pharmaceuticals is a major health issue. Therefore, there is a need for efficient techniques to remove pharmaceutical pollutants. Here,...     

High-altitude and long-range transport of aerosols causing regional severe haze during extreme dust storms explains why afforestation does not prevent storms

Environmental Chemistry Letters - Climate change is predicted to induce more extreme events such as storms, heat waves, drought and floods. Dust storms are frequently occurring in northern China....     

Effects of Al3+ on pollutant removal and extracellular polymeric substances (EPS) under anaerobic,anoxic and oxic conditions

The highest removal efficiencies of COD and TN were achieved under 10 mg/L of Al³⁺. The highest TP removal efficiency occurred under 30 mg/L of Al³⁺. EPS, PS and PN concentrations increased with the addition of Al³⁺. Sludge properties significantly changed with the addition of Al³⁺. Aluminum ions produced by aluminum mining, electrolytic industry and aluminum-based coagulants can enter wastewater treatment plants and interact with activated sludge. They can subsequently contribute to the removal of suspended solids and affect activated sludge flocculation, as well as nitrogen and phosphorus removal. In this study, the effects of Al³⁺ on pollutant removal, sludge flocculation and the composition and structure of extracellular polymeric substances (EPS) were investigated under anaerobic, anoxic and oxic conditions. Results demonstrated that the highest chemical oxygen demand (COD) and total nitrogen (TN) removal efficiencies were detected for an Al³⁺ concentration of 10 mg/L. In addition, the maximal dehydrogenase activity and sludge flocculation were also observed at this level of Al³⁺. The highest removal efficiency of total phosphorus (TP) was achieved at an Al³⁺ concentration of 30 mg/L. The flocculability of sludge in the anoxic zone was consistently higher than that in the anaerobic and oxic zones. The addition of Al³⁺ promoted the secretion of EPS. Tryptophan-like fluorescence peaks were detected in each EPS layer in the absence of Al³⁺. At the Al³⁺ concentration of 10 mg/L, fulvic acid and tryptophan fluorescence peaks began to appear, while the majority of protein species and the highest microbial activity were also detected. Low Al³⁺ concentrations (<10 mg/L) could promote the removal efficiencies of COD and TN, yet excessive Al³⁺ levels (>10 mg/L) weakened microbial activity. Higher Al³⁺ concentrations (>30 mg/L) also inhibited the release of phosphorus in the anaerobic zone by reacting with PO₄^3-.     

Homology modeling of anti-parathion antibody and its interaction with organophosphorous pesticides and analogues

The mechanism of specific recognition in pesticide immunochemistry was investigated by computer-based strategy, and a rapid method for the identification of antibody specificity was developed. Based on the previously produced anti-parathion monoclonal antibody (mAb), the DNA sequence was analyzed by polymerase chain reaction (PCR). From the translated amino acid sequences, a three-dimensional structure of the antibody was constructed by homology modeling method, and then it was coordinated by 1 ns molecular dynamics under the explicit solvent condition. The stereochemical property and folding quality were further assessed by Procheck and Profile-3D. The self-compatibility score for the antibody model was 98.7, which was greater than the low score 46.2 and close to the top score 102.6. In addition, parathion and several structural analogues were docked to the constructed antibody structure. The docking results showed that the interaction energy (-40.54 kcal/mol) of antibody-parathion complex was the lowest among all the tested pesticides, which accounted for the high specificity of the antibody to parathion and perfectly matched with the experimental data. Moreover, three residues, Phe165, Asp107 and Thr100 were recognized as the most important residues for antibody reacting with parathion. The interaction energy negatively correlated with the antibody specificity.     

Ca5（AsO4）3OH的溶解度与稳定性研究

通过在不同pH值,温度等条件下Ca5（AsO4）3OH的溶解,确定其稳定存在的pH值范围,得出它的溶度积和生成的自由能（ΔG0f）。结果表明,Ca5（AsO4）3OH在水中的溶解度和稳定范围与pH和温度有关,在酸性条件下（初始pH=2）它的溶解度较大,而且在水中的溶解度随着温度的升高而降低。利用PHREEQC程序计算确定Ca5（AsO4）3OH的溶度积为10-40.86,生成自由能ΔG0f为-5 063.53 kJ/mol。利用JADE5软件计算得到其晶格参数a=b=9.696,c=6.967和晶胞体积为567.304 3。     

聚合酶链反应-变性梯度凝胶电泳技术研究梯田式人工湿地微生物群落动态变化

采用聚合酶链反应(PCR)—变性梯度凝胶电泳(DGGE)技术对梯田式人工湿地(TTCW)和复合垂直流式人工湿地(IVCW)生活污水处理系统内的微生物群落结构的动态变化及其对生活污水处理效果的影响进行了对比研究。结果表明:(1)TTCW和IVCW对生活污水均具有较好处理效果,其COD去除率平均分别为76.2%和72.6%、TP去除率平均分别为90.7%和85.6%、NH4+-N去除率平均分别为65.2%和58.8%;TTCW增氧作用明显。(2)2种人工湿地内均存在丰富的微生物群落,并均存在共有的微生物种群;在湿地沿程不同位置均存在一定数量的优势种群。(3)TTCW强化了大气复氧能力,使得湿地内DO较相同深度的IVCW的高。TTCW具有较强的污染物去除能力,特别是具有高效的脱氮除磷能力。这种能力可能主要是TTCW中微生物群落结构的变化所致。