Genotoxicity removal of reclaimed water during ozonation

Genotoxicity in wastewater and reclaimed water now is gaining increased attention because of genotoxins' potential damage to the ecosystem and human health. The effect of ozonation on genotoxicity in reclaimed water was investigated. It was found that ozonation decreased the genotoxicy dramatically in three tertiary treatment plants. In the further batch ozonation experiment in laboratory,secondary effluent sample used exhibited the genotoxicity of(41.1 ± 4.1) μg 4NQO/L. Ozonation with a dose of 10 mg O3/L completely removed the genotoxicity in secondary effluent. However,after ozonation, the dissolved organic carbonvalue of the sample didn't change much but the specific ultraviolet absorbance(SUVA) value dropped sharply. With the help of Fourier transform infrared spectroscopy, ozonation was found to change chemical aliphatic carbon and C–O of the dissolved arganic matter, which might be the reason of the significant decreases of SUVA and genotoxicity.     

Carbonyl emissions from heavy-duty diesel vehicle exhaust in China and the contribution to ozone formation potential

Fifteen heavy-duty diesel vehicles were tested on chassis dynamometer by using typical heavy duty driving cycle and fuel economy cycle. The air from the exhaust was sampled by 2,4- dinitrophenyhydrazine cartridge and 23 carbonyl compounds were analyzed by high performance liquid chromatography. The average emission factor of carbonyls was 97.2 mg/km, higher than that of light-duty diesel vehicles and gasoline-powered vehicles. Formaldehyde, acetaldehyde, acetone and propionaidehyde were the species with the highest emission factors. Main influencing factors for carbonyl emissions were vehicle type, average speed and regulated emission standard, and the impact of vehicle loading was not evident in this study. National emission of carbonyls from diesel vehicles exhaust was calculated for China, 2011, based on both vehicle miles traveled and fuel consumption. Carbonyl emission of diesel vehicle was estimated to be 45.8 Gg, and was comparable to gasolinepowered vehicles （58.4 Gg）. The emissions of formaldehyde, acetaldehyde and acetone were 12.6, 6.9, 3.8 Gg, respectively. The ozone formation potential of carbonyls from diesel vehicles exhaust was 537 mg O3/km, higher than 497 mg O3/km of none-methane hydrocarbons emitted from diesel vehicles.     

Acute and chronic toxic effects of Pb2+ on polychaete Perinereis aibuhitensis：Morphological changes and responses of the antioxidant system

Perinereis aibuhitensis was used to assess adverse biological effects caused by acute and chronic Pb2＋exposure in artificial seawater under controlled laboratory conditions. In 96-hr acute toxicity experiments,the morphological changes showed a positive time/dose-dependent tendency,and the 96-hr LC50 value of Pb2＋was 686.41 mg/L. The responses of enzymatic and non-enzymatic antioxidants in tissues including catalase（CAT）,peroxidase（POD）,superoxide dismutase（SOD）,glutathione peroxidase（GSH-PX）,malondialdehyde（MDA） and the content of total soluble protein（TSP）,were investigated on days 1,4,7 and 10 after Pb2＋exposure under chronic toxicity testing. Results showed that the activation of the antioxidant system in P. aibuhitensis depended on the Pb2＋concentration and the duration of exposure time.Specifically,POD and SOD activities were induced on the first day of the exposure and decreased to the control level on day 10 after exposure. Therefore,these two indexes could be used to indicate oxidative stress associated with P. aibuhitensis exposure to Pb2＋.     

微纳米气泡改善杭州城市河道水生态环境的工程应用研究

于2013年4月至6月在杭州城市河道对微纳米气泡改善河道水生态环境进行了持续的原位监测实验.结果表明,与对照区相比,试验区水体温度平均升高0.7℃,pH增大0.2,溶解氧增加1.0 mg/L,而TDS浓度降低42 mg/L;水质污染指标高锰酸盐指数、总氮、氨氮、总磷平均浓度分别降低了8.45 mg/L、6.78 mg/L、8.90 mg/L和0.58 mg/L.由此可推测微纳米气泡在一定程度上能有效净化水质,为恢复良好水生生态环境提供新的方法和技术手段.     

高效液相色谱法测定水中的六种邻苯二甲酸酯研究

建立了高效液相色谱法测定水中六种邻苯二甲酸酯(邻苯二甲酸二甲酯、邻笨二甲酸二乙酯、邻苯二甲酸二丁酯、邻苯二甲酸二(2-乙基己基)酯、邻苯二甲酸二辛酯、邻苯二甲酸丁基苄酯)的检测方法.对水样中邻苯二甲酸酯的萃取条件和高效液相色谱分析条件进行优化,采用正己烷二次萃取,浓缩定容后分析,以乙腈-水为流动相梯度洗脱,紫外检测波长226 nm,16 min可将六种邻苯二甲酸酯分离出.方法的检出限为0.13μg/L ～0.37 μg/L,加标回收率为78.6％～118.5％,相对标准偏差为0.82％～2.17％,是一种理想的测定水中六种邻苯二甲酸酯的方法.     

基于灰色关联分析的杭州市造纸企业环境资源量化评价实证研究

根据杭州市2013年环境统计年鉴相关数据,以发展经济学理论为指导,建立杭州市造纸企业环境资源量化评价指标体系,利用灰色关联分析方法对杭州市216家企业的环境资源综合情况进行排序,并根据排序结果进行讨论分析,为相关决策部门提供参考.通过研究得出,杭州市造纸企业按照评价体系分为三档类型进行管理.第一档企业为先进企业,优先支持;第二档为一般企业,主要是整治提升;第三档为落后企业,关停淘汰.     

从太空中死里逃生

1970年4月13日傍晚,正在飞行的美国阿波罗飞船内的一个氧气舱发生了强烈的爆炸,阿波罗13号太空飞船是在当天13点13分发射升空的。在狭窄的指挥舱里,宇航员们听到了砰的一声巨响,并觉得飞船在颤抖。接着刺耳的警笛声响彻了整个飞船,同时控制板上的警示灯也开始闪烁。这些闪烁的灯光信号表明,对航行和生命至关重要的电和氧的储量正在极快地减少。     

脱水污泥制备含炭吸附剂及其应用研究

采用热解炭化法、物理活化法、化学活化法制备污泥含炭吸附剂,通过静态吸附实验研究各种影响污泥含炭吸附剂吸附性能的因素.实验结果表明,采用化学活化法制得的污泥含炭吸附剂吸附性能最好,在以ZnCl2为活化剂、锯末添加剂投加量为脱水污泥质量的1%、ZnCl2为3 mol/L、活化温度为450 ℃、活化时间为1.5 h、固液质量比(干污泥与活化剂溶液的质量比)为1:4的最佳制备条件下,制得的污泥含炭吸附剂碘吸附值在520 mg/g以上,产物收率>60%,比表面积>230 m2/g,总孔容积为0.35 mL/g,其中微孔容积为0.08 mL/g,中孔容积为0.23 mL/g.利用其处理城市污水,其对COD、色度、TP的去除率好于选定的商品颗粒活性炭.     

氯苯嘧啶醇在水体中的光解机制研究

以太阳光为实验光源研究了氯苯嘧啶醇在水溶液中的光解,考察了pH、水体类型、溶解氧及卤素离子等对其光解的影响.结果表明,氯苯嘧啶醇在水溶液中的光解符合一级动力学方程,在不同水体中氯苯嘧啶醇光解的速率大小顺序为:重蒸水>水库水>湖水>池塘水;氯苯嘧啶醇光解的半衰期随着溶液pH的增大而延长,当pH为5、7、9、11时光解半衰期分别为5.00、6.86、7.45、7.53 h;3种卤素离子对氯苯嘧啶醇光解有很大的影响,均表现出强的猝灭作用,3种离子的猝灭能力的大小顺序为Ⅰ->Br->Cl-;溶解氧和三重态光猝灭剂山梨酸均对氯苯嘧啶醇在水中的光解没有影响,而三重态光敏剂丙酮则对其光解有较强的猝灭作用,表明氯苯嘧啶醇在水中的光解主要以直接光解为主,光解过程不经历三重态.     

山区城镇泥石流灾害风险控制模式探讨

受全球气候变化的影响,灾害性天气频发,使得山区泥石流危害极为严重.作为人口和经济高度集中的山区城镇也就成为泥石流危害的主要对象.针对山区城镇泥石流危害特征及风险控制现状,引入地理学中的同心圆理论,探讨了山区城镇泥石流风险控制的"同心圆模式",分析了"同心圆模式"中各风险控制层对灾害风险的控制机制及效应,提出城镇泥石流风险控制应遵循多层防范、逐级降低的思路,研究可为山区城镇的减灾管理提供合理的参考.