Diclofenac sodium aqueous systems at low concentrations: Interconnection between physicochemical properties and action on hydrobionts

Diclofenac sodium(DS) is a widely used nonsteroidal anti-inflammatory drug(NSAIDs).NSAIDs are poorly removed during standard wastewater treatment.The consequences of the presence of NSAIDs in rivers and lakes at 10~(-11)–10~(-8) mol/L are not yet established;therefore, ecotoxicologists have focused their efforts on studying the effect of lowconcentration NSAIDs on fish and hydrobionts, and also on predicting the potential risks to humans.Literature provides some information about the bioeffects of some NSAID solutions in low concentrations but there is no physicochemical explanation for these phenomena.Studying the physicochemical patterns of DS solutions in the low range of concentrations and establishing an interconnection between the solutions' physicochemical properties and bioeffects can provide a conceptually new and important source of information regarding the unknown effects of DS.The physicochemical properties and action of DS solutions on Ceriodaphnia affinis cladocerans,Paramecium caudatum infusoria, Chlorella vulgaris unicellular green algae, as well as on the growth of the roots of Triticum vulgare wheat seeds, were studied in the calculated concentration range of 1 × 10~(-3)–1 × 10~(-18) mol/L.The relationship between these phenomena was established using the certified procedures for monitoring the toxicity of natural water and wastewater.It was shown for the first time that water solutions of DS are dispersed systems in which the dispersed phase undergoes a rearrangement with dilution, accompanied by changes in its size and properties, which affects the nonmonotonic dependences of the system's physicochemical properties and could cause nonmonotonic changes in action on hydrobionts in the low concentration range.     

雾霾的预防和控制措施研究

雾霾的形成,主要是城市静风、大气逆温层以及大气中细颗粒物污染的综合效应。控制和预防雾霾,应该加强机动车的监控、鼓励清洁能源汽车的研发、生产和销售。大力发展城市公共交通、建设城市公共自行车网络,严格建筑扬尘的管理和对重点大气污染源的治理,实行联防联控和区域联动机制,环保部门要全面开展雾霾监测,会同气象部门,结合气象参数等各方面资料,建立健全雾霾的预警预报体系,同时倡导全民低碳出行的生产、生活理念以及加强环保的宣传教育,提高全民环保意识。     

黑龙江省重要水功能区水质现状评价与达标分析研究

及时掌握水功能区水质现状与达标状况,对加强水功能区监督管理和水环境保护具有重要作用,为水功能区保护与管理提供建议,从而保障水资源的可持续利用。该文根据2011年黑龙江省重要江河湖泊水功能区监测资料,对黑龙江省重要水功能区水质现状及达标率进行分析评价,结果表明,黑龙江省重要水功能区的个数达标率为29.0%,长度达标率为19.6%,评价结果与实际情况基本相符,同时阐述了水功能区达标率低,监测能力水平不高等问题。最后给出解决措施是:城市污水处理及中水回用工程,水体综合治理和生态修复措施,加强水质监测现代化建设,提升监测能力等具体措施。     

Efficiency of removal of cadmium from aqueous solutions by plant leaves and the effects of interaction of combinations of leaves on their removal efficiency

Removal of cadmium from aqueous solutions using 20 species of plant leaves and combinations of these leaves have been studied. Several factors affecting the removal efficiency have been studied. The most efficient types of plant leaves for the removal of cadmium are those of styrax, plum, pomegranate and walnut. The interaction effect of the combined leaf samples on the efficiency of removal of cadmium has been found to be additive in combinations involving styrax plant leaves but seems to be antagonistic in all other combinations. The optimum experimental conditions for removal of cadmium have been found to be at pH 4.1, using high concentrations of naturally dried plant leaves, using ground leaves and to remove cadmium from agitated aqueous solutions. The percentage of metal removed at an initial cadmium concentration of 10mg/l by the most efficient types of leaves have been found to be 85% for styrax leaves, 85% for plum leaves, 80% for pomegranate leaves, 78% for walnut leaves and 77% for meddler leaves. The presence of foreign ions or complexing agents has been found to reduce the efficiency of removal of cadmium by plant leaves. About 80-85% of the cadmium in charged plant leaves has been released under the influence of changing the pH of the solution, addition of competing ions and the addition of EDTA. The results of removal of cadmium by plant leaves have been found to follow the Freundlich adsorption isotherm, first-order reaction with respect to cadmium and to have intra-pore diffusion as the rate-limiting step.     

Preparation1 and utilization of wheat straw anionic sorbent for the removal of nitrate from aqueous solution

In order to reduce the impact of eutrophication caused by agricultural residues (i.e. excess nitrate) in aqueous solution, economic and effective anionic sorbents are required. In this article, we prepared anionic sorbent using wheat straw. Its structural characteristics and adsorption properties for nitrate removal from aqueous solution were investigated. The results indicate that the yield of the prepared anionic sorbent, the total exchange capacity, and the maximum adsorption capacity were 350%, 2.57 mEq/g, and 2.08 mmol/g, respectively. The Freundlich isotherm mode is more suitable than the Langmuir mode and the adsorption process accords with the first order reaction kinetic rate equation. When multiple anions (SO42-, H2PO4-, NO3-, and NO2-) were present, the isotherm mode of prepared anionic sorbent for nitrate was consistent with Freundlich mode; however, the capacity of nitrate adsorption was reduced by 50%. In alkaline solutions, about 90% of adsorbed nitrate ions could be desorbed from prepared anionic sorbent. The results of this study confirmed that the wheat straw anionic sorbent can be used as an excellent nitrate sorbent that removes nitrate from aqueous solutions.     

Removal of heavy metals from aqueous solution by sawdust adsorption

The adsorption of lead, cadmium and nicel from aqueous solution by sawdust of walnut was investigated. The effect of contact time, initial metal ion concentration and temperature on metal ions removal has been studied. The equilibrium time was found to be of the order of 60 min. Kinetics fit pseudo first-order, second-order and intraparticle diffusion models, hence adsorption rate constants were calculated. The adsorption data of metal ions at temperatures of 25, 45 and 60~C have been described by the Freundlich and Langmuir isotherm models. The thermodynamic parameters such as energy, entropy and enthalpy changes for the adsorption of heavy metal ions have also been computed and discussed. Ion exchange is probably one of the major adsorption mechanisms for binding divalent metal ions to the walnut sawdust. The selectivity order of the adsorbent is Pb（I1）~Cd（II）〉Ni（I1）. From these results, it can be concluded that the sawdust of walnut could be a good adsorbent for the metal ions from aqueous solutions.     

Effect of competing solutes on arsenic（Ⅴ） adsorption using iron and aluminum oxides

The study focused on the effect of several typical competing solutes on removal of arsenic with Fe_2O_3 and AL_2O_3.The test results indicate that chloride,nitrate and sulfate did not have detectable effects,and that selenium(Ⅳ)(Se(Ⅳ))and vanadium(Ⅴ)(V(Ⅴ)) showed slight effects on the adsorption of As(Ⅴ)with Fe_2O_3.The results also showed that adsorption of As(Ⅴ)on AL_2O_3 was not affected by chloride and nitrate anions,but slightly by Se(Ⅳ)and V(Ⅴ)ions.Unlike the adsorption of As(Ⅴ)with Fe_2O_3,that with Fe_2O_3 was affected by the presence of sulfate in water solutions.Both phosphate and silica have significant adverse effects on the adsorption of As(Ⅴ)adsorption with Fe_2O_3 and Al_2O_3.Compared to the other tested anions,phosphate anion was found to be the most prominent solute affecting the As(Ⅴ)adsorption with Fe_2O_3 and Al_2O_3.In general,Fe_2O_3 has a better performance than Al_2O_3 in removal of As(Ⅴ)within a water environment where multi competing solutes are present.     

农村民居抗震性能存在的问题及对策

本文通过分析农村民居抗震性能存在的问题，从专家参与设计房屋抗震加固方案、加强房屋抗震知识宣传教育、推广典型、加强村镇建设项目抗震设防的指导和管理四个方面提出了提高农村民居抗震性能的对策及措施。     

模拟酸雨的土壤淋洗液对马尾松华山松幼苗生长的影响

用不同酸度的模拟酸雨土壤淋洗液作培养液，以中性降水土壤淋洗液作对照，研究了马尾松、华山松幼苗受土壤溶液酸度及Ａｌ３＋浓度毒害的症状。观测了受毒害后的可视性症状出现的时间、根系伸长生长受阻的情况、植物体各部分生物量以及一些物质含量的浓度。结果表明，植物体受土壤溶液中各种浓度的Ｈ＋与Ａｌ３＋影响后，普遍出现根部膨胀、植物体发红的受害症状。低酸度模拟酸雨的土壤淋洗液可在一定时间内使幼苗生物量呈增加的趋势，高酸度模拟酸雨处理后的情况则与之相反。与可视性症状相比，植物体中一些物质的含量对Ｈ＋和Ａｌ３＋浓度更加敏感；根系部分敏感于地上部分；华山松敏感于马尾松。     

宜昌市饮用水源地保护问题及对策

“十一五”全国主要污染物排放总量减少10％已成为约束性指标。面对严峻的形势,尽管社会各界空前重视,但各地减排工作进展不平衡,仍存在经济增长方式仍然粗放、政策措施落实不到位等问题。针对存在问题,提出了加大产业结构调整力度、污染防治资金投入、实施严格的环境准入制度等政策措施,完善减排体系、适时修改国家污染减排核算细则等技术措施,加大环境执法和环境监管力度、减排宣传力度等保障措施。