杭州市区大气能见度变化趋势及其与主要污染物相关性分析

利用2004-2006年地面气象观测资料和同期环境空气质量自动监测数据,分析了杭州市区大气能见度变化趋势及其与主要污染物的相关性.结果表明,杭州市区能见度的日分布特征为14时最好,8时最差;季节变化特征为夏季>春季>秋季>冬季,全年仅7月能见度超过10 km;SO2、NO2、PM10浓度均随能见度增高而逐渐降低;影响能见度的首要因子为相对湿度和PM2.5,能见度与PM2.5浓度具有较好的相关性.     

上海市机动车排气污染负荷的估算

根据机动车行驶工况和污染物排放系数测定，定量计算了近年来上海市机动车在实际行驶工况下的污染物排放量，匀速行驶时间仅占１３．８％，１９９５年机动车排放的ＣＯ、ＮＭＨＣ和ＮＯｘ负荷已占中心城区大气污染物排放总量的７６％，９３％和４４％，机动车已成为造成上海市区大气污染的主要排放源。     

Optimizing sludge dewatering with a combined conditioner of Fenton's reagent and cationic surfactant

Enhancing sludge dewatering is of importance in reducing environmental burden and disposal costs. In this work, a cationic surfactant, cetyl trimethyl ammonium bromide (CTAB), was combined with Fenton's reagent for sludge dewatering. Results show that the Fenton-CTAB conditioning significantly promotes the sludge dewatering. Using combined techniques of response surface methodology and uniform design, dosages of Fe²⁺, H₂O₂, and CTAB for water content response were optimized to be 89, 276, and 233?mg/g dry solids (DS), respectively. The water content of sludge decreased from 79.0% to 66.8% under the optimal conditions. Compared with cationic polyacrylamide, the Fenton-CTAB system exhibited superior sludge dewatering performance. To gain insights into the mechanisms involved in sludge dewatering, the effects of Fenton-CTAB conditioning on the composition of extracellular polymeric substances (EPS) and the morphology of the sludge flocs were investigated. The decomposition of EPS into some dissolved organics and the release of proteins in tightly bound EPS facilitated the conversion of bound water to free water and further reduced the water content of sludge cake. After conditioning, morphology of sludge showed aggregation. Overall, the enhanced sludge dewatering by Fenton-CTAB treatment provides an efficient way for management of sewage sludge.     

污泥用作渗透性反应壁填料的可行性研究

渗透性反应壁(permeable reactive barrier,PRB)现已被广泛用来治理酸性采矿废水.寻求高效的有机反应填料是运用渗透性反应壁技术的关键.采用批式吸附实验和批式微生物培养实验研究了城市污水处理厂的消化污泥作为渗透性反应壁有机填料的可行性.批式吸附实验结果表明,污泥对Zn2+和Cd2+具有较强的吸附能力,最大吸附量分别为13.62mg·g-1和15.60mg·g-1.在批式微生物培养实验中,SO24-浓度从实验初期700mg·L-1左右下降到结束时的300mg·L-1以下,去除率为60%～70%;Fe和重金属污染物(Zn、Cd)都得到了完全去除.结果表明,污泥是一种合适的渗透性反应壁填料.     

垃圾填埋场渗滤液的防渗措施和地下水的污染防护

本文首先介绍了垃圾填埋场对其附近地下水体的潜在污染危害,着重介绍了为防止地下水体污染填埋场而采用的防渗措施,包括封场后的顶部覆盖层、中间夹层、底部集排系统以及底层和四周的衬层系统.然后介绍了由于防渗措施局部失效或其他原因(如破损、腐蚀等)引起渗滤液污染地下水以后可采用的防护方法(物理和生化技术),主要有隔离措施、地下曝气、反应墙或反应井、人工补给或抽水、水力截获、原位生物修复技术.最后简要介绍了对填埋场污染地下水这一问题的研究现状,并对这一方面的技术研究提出展望.     

胶州市东部滞洪区水污染情况调查及相应对策与建议

通过对胶州市东部滞洪区水质现状的调查,发现水环境污染情况较为严重.水污染的主要原因是污水直接入渠,水体自净能力差.可通过实施截污与污水收集系统建设相结合、防止污水入湖及实施东部滞洪区湖水自净建设工程等措施改善东部滞洪区的污染现状.     

湿式氧化法气体脱硫的现状与趋势

液相氧化法脱除H2S具有脱硫效率高，可将H2S一步转化为硫元素，大多数脱硫剂可以再生等特点，目前研究过的液相氧化法有百余种，其中有工业价值的20余种。文中介绍了几种典型的液相脱硫工艺：砷基工艺点基工艺和铁基工艺的化学反应原理及发展趋势。     

A high activity of Ti/SnO2-Sb electrode in the electrochemical degradation of 2,4-dichlorophenol in aqueous solution

Electrochemical degradation of 2,4-dichlorophenol (2,4-DCP) in aqueous solution was investigated over Ti/SnO₂-Sb anode. The factors influencing the degradation rate, such as applied current density (2-40 mA/cm²), pH (3-11) and initial concentration (5-200 mg/L) were evaluated. The degradation of 2,4-DCP followed apparent pseudo first-order kinetics. The degradation ratio on Ti/SnO₂-Sb anode attained > 99.9% after 20 min of electrolysis at initial 5-200 mg/L concentrations at a constant current density of 30 mA/cm² with a 10 mmol/L sodium sulphate (Na2SO4) supporting electrolyte solution. The results showed that 2,4-DCP (100 mg/L) degradation and total organic carbon (TOC) removal ratio achieved 99.9% and 92.8%, respectively, at the optimal conditions after 30 min electrolysis. Under this condition, the degradation rate constant (k) and the degradation half-life (t_1/2) were 0.21 min^-1 and (2.8±0.2) min, respectively. Mainly carboxylic acids (propanoic acid, maleic acid, propanedioic acid, acetic acid and oxalic acid) were detected as intermediates. The energy efficiencies for 2,4-DCP degradation (5-200 mg/L) with Ti/SnO₂-Sb anode ranged from 0.672 to 1.602 g/kWh. The Ti/SnO₂-Sb anode with a high activity to rapid organic oxidation could be employed to degrade chlorophenols, particularly 2,4-DCP in wastewater.     

电子受体亚硝酸氮在反硝化除磷过程中的作用

针对先前文献提到的亚硝酸氮在反硝化除磷中存在着一定的抑制作用,以亚硝酸氮作为电子受体,对其在缺氧反硝化吸磷过程中的抑制影响进行了大量的静态烧杯试验.结果表明,在亚硝酸氮浓度大于30mg·L-1的时候,确实存在严重的抑制作用,而且该临界抑制浓度与污泥的特性和运行操作条件等因素有关;但是在亚硝酸氮浓度低于25mg·L-1的情况下不会对反硝化条件下磷的吸收产生毒害作用,相反地,它可以取代氧气、硝酸氮做为良好的电子受体用来进行缺氧段磷的生物摄取,在反硝化除磷中表现一定的积极作用.     

安全优质饮用水

水中的微量元素是人体微量元素的主要来源,而且饮用水的硬度和总溶解性固体和当地居民心脏病的死亡率有确定的正相关性。ＴＤＳ越高,心脏病发作率越少。健康的水应是去除了有机微污染,三致物质,病原菌,病毒和病原原生动物的,并且含有适量微量元素和矿物质的安全和有益于健康的水。