Abundance,spatial distribution,and physical characteristics of microplastics in stormwater detention ponds

Despite extensive research on microplastics (MP) in marine environments, little is known about MP abundance and transport in terrestrial systems. There is, therefore, still little understanding of the main mechanisms driving the substantial transport of MP across different environmental compartments. Storm events can transport MP beyond boundaries, such as from the land to groundwater or the ocean, as has already been discovered for organic carbon transport. Urban stormwater detention ponds are suitable environments to study the impact of stormwater on the environmental fate and transport of MP. Herein, we investigate the longitudinal and vertical distribution of MP within two detention ponds with different physical characteristics. Soil samples were collected at various locations and from multiple depths (surface and subsurface layers) for measuring MP concentrations using fluorescence microscopy. Our findings show that MP are retained more near the inlet of the ponds, and MP of larger sizes were found more abundantly near inlets than outlets. We also found that MP mass and sizes decrease from surface soil to subsurface soil. In the pond, where vegetation (grass root network) was more considerable, MP were found more evenly distributed along the depth. In terms of shape, the fragments were the most abundant MP shape.     

城市污水超滤再生处理效果及安全性评价

为了考察超滤工艺再生城市污水的可行性 ,对超滤膜处理城市污水的再生效果进行了实验研究 ,研究结果表明 ,虽然超滤对某些指标处理效果明显 ,但是单一的超滤工艺不能完全保证再生回用水的安全性。     

油田采油污水处理工艺的试验研究

采用化学絮凝与SBR联合的二段法对采油污水进行处理,采油污水经第一段化学破乳絮凝后,COD去除率可达到85％以上,油去除率可达到95％以上;第一段处理出水再经第二段SBR处理后COD又得到进一步去除,出水中COD≤60mg/L,BOD_5≤30mg/L、SS<30mg/L、油<10mg/L,达到了油田回注水标准和含油污水的国家二级排放标准,可实现废水的资源化。     

石灰处理在电厂回用水处理中的应用研究

通过对河北2个电厂进行的回用水石灰处理试验,确定对不同回用水处理的控制指标,考察石灰处理的效果及特点。试验证明石灰处理用于电厂回用水处理是可靠的。     

洗浴中水回用可行性分析

以某城市模块的公共浴室和洗衣房排水为处理对象,研究采用合适可行的工艺流程进行处理。技术和经济分析结果表明,采用混凝沉淀+过滤+消毒的处理工艺对洗浴排水进行处理,出水达到中水回用要求。     

沈阳市中水回用现状分析及展望

介绍了国内外中水回用概况,结合沈阳市的水资源、水污染、中水回用现状情况,分析沈阳市中水回用的制约因素,提出沈阳市中水回用的措施及建议.     

湿法破碎在废弃线路板资源化中的应用

根据废弃线路板非金属组成及破碎特性,通过热重-红外分析热解实验等手段证实和研究了干法破碎中存在的二次污染问题,提出了应用湿法破碎的解决方案。通过干、湿法破碎实验结果的对比得出:各粒级湿法破碎的产率有所变化,主要是(-5+2)mm粗粒级及0·045mm以下微细粒级物料的产率都有明显的增多,但整体上来看并没有改变物料的粒度分布特征。最后,就差异存在的原因作了分析。     

两种高浓度酚醛树脂生产废水的树脂吸附处理及其资源化研究

采用XDA-1树脂吸附和碱液解吸工艺对两种高浓度酚醛树脂生产废水进行处理和回收研究。结果显示,在室温、pH 4~6、流速1~2BV/h条件下,两种废水的酚浓度分别从9500mg/L和24500mg/L降低到1mg/L和5mg/L,CODC r分别从18800mg/L和212000mg/L降低到1450mg/L和97500mg/L。用浓度4%的NaOH溶液在60℃条件下进行解析,解吸效率达99%。从两种废水中分别回收了浓度8%~12%的羟甲基酚和甲基苯酚,既减少了对环境的污染,又回收了资源。     

蜡染废水在线处理回用及热能回收工程实例

采用絮凝沉淀-ClO2脱色-砂滤-微波无极紫外光催化氧化工艺对青岛凤凰印染有限公司蜡染印花水洗废水进行处理,详细论述了该工艺的运行特点、处理及回用效果。结果表明,在进水COD及色度波动很大的情况下,处理后废水水质长期稳定达到COD100 mg/L,色度10倍,其他各项水质指标均可满足蜡染水洗工序的生产回用要求,并回收了水中的热能。废水回用率达80%,日节水200 t,节约热能折合成标准煤约为1 t,为印染行业完成节能20%,减排20%的总体目标提供了新的思路。     

Chemical fractionation of Cu and Zn in stormwater, roadway dust and stormwater pond sediments

This study evaluated the chemical fractionation of Cu and Zn from source to deposition in a stormwater system. Cu and Zn concentrations and chemical fractionation were determined for roadway dust, roadway runoff and pond sediments. Stormwater Cu and Zn concentrations were used to generate cumulative frequency distributions to characterize potential exposure to pond-dwelling organisms. Dissolved stormwater Zn exceeded USEPA acute and chronic water quality criteria in approximately 20% of storm samples and 20% of the storm duration sampled. Dissolved Cu exceeded the previously published chronic criterion in 75% of storm samples and duration and exceeded the acute criterion in 45% of samples and duration. The majority of sediment Cu (92-98%) occurred in the most recalcitrant phase, suggesting low bioavailability; Zn was substantially more available (39-62% recalcitrant). Most sediment concentrations for Cu and Zn exceeded published threshold effect concentrations and Zn often exceeded probable effect concentrations in surface sediments.