透水砖铺装对雨水径流热污染控制效果实验

随着海绵城市的快速发展,透水砖铺装在实际工程中得到了广泛应用,但其对雨水径流热污染控制效果尚缺乏系统研究。采用人工模拟降雨方法,以不透水沥青路面为参考,研究了透水砖铺装系统对雨水径流温度的削减效果,具体包括透水砖铺装表面外排雨水径流温度、渗透出水温度以及各结构层的温度变化。实验结果表明:当重现期为5年一遇,透水砖铺装面层初始温度为35,42,47 ℃时,与不透水沥青相比,透水砖铺装面层外排径流温度可削减1.4~1.8 ℃,且面层初始温度越高,外排雨水径流温度越高,渗透出水温度也越高;透水砖铺装各结构层可削减渗透部分雨水径流的温度,渗透出水温度相对于径流温度降低3.5~5.2 ℃;降雨强度对透水砖面层外排雨水径流温度有显著影响,而对渗透出水温度影响较小。因此,透水砖铺装可有效削减雨水径流对城市水体的热污染。     

透水砖铺装的设施构造对运行效果的影响

为考察缝隙透水砖铺装的基层构造与材料对设施运行效果的影响,在上海市区建造了2个缝隙透水砖铺装(permeable interlocking concrete pavement,PICP)与1个不透水混凝土铺装(concrete pavement,CP)停车场,其中2个缝隙透水砖铺装分别采用水泥稳定碎石(PICP1)和普通碎石(PICP2)作为基层结构.在2018年实际降雨条件下对2个设施的水文效果及底部出流水质进行了长期监测.结果表明PICP1与PICP2的年径流总量控制率相近,分别为37. 0%和38. 7%,PICP1的峰值削减率及峰现延迟时间略优于PICP2.水质控制效果方面,PICP1比PICP2有更好地NH_4~+-N转化效果,两种设施底部出流均存在NO_3~--N淋出的现象; PICP1底部出流的TSS、TP、颗粒态磷和溶解态磷浓度均低于PICP2.采用水泥稳定碎石作为基层有助于提高设施的水质净化效果,并改善设施的水文控制效果.     

高地下水位地区透水铺装控制径流污染的现场实验

为确定高地下水位地区使用透水铺装对地下水水质的影响,在上海市区建造了3种实验性透水铺装停车场及1个不透水铺装对照,监测实际降雨条件下3种实验设施进、出水水质,考察其对径流中污染物的去除效果并评价设施对地下水造成污染的可能性.结果表明,3种设施对TP、TSS、COD、Cr、Mn、Cu、Zn、Pb及石油类均有良好的去除效果,而对TN的去除效果较差;3种设施中均发生了明显的NO-3-N释放现象;以水泥稳定碎石为基层的缝隙透水砖铺面以及碎石基层的缝隙透水砖铺面对NH+4-N去除效果明显好于透水混凝土铺面;不同透水铺装设施出水水质除NH+4-N之外无显著差异;现场地下水质总体上劣于上海市地下水背景值,而3种透水铺装出水总体上劣于现场地下水,且多项指标属于或接近地下水V类标准.在高地下水位地区使用无防渗衬垫透水铺装存在污染地下水的风险.     

新型透水铺装对雨水径流水量和水质控制效果现场研究

前期研究表明,新型透水铺装通过在结构层引入毛细柱,不仅可有效提高设施在高地下水位地区应用的水文控制效果从而缓解城市内涝风险,还能够有效缓解城市热岛从而调节城市热环境。为了探讨新型透水铺装对于城市雨水径流污染的控制效果,实验构建了新型透水铺装(IPP)、传统混凝土砖缝隙透水铺装(PICP)和不透水混凝土路面(CP)3种不同的停车场现场设施,基于全年实际降雨条件下监测数据,分析对比了IPP和PICP对于雨水径流水质净化的效果差异,评估了2种设施全年所排放的城市面源污染负荷。实验结果表明：与PICP设施相比,IPP对NO^-₃-N、TN的总污染负荷控制率分别从14.4%、37.3%提高至45.6%、58.8%,对TSS和COD总污染负荷控制率分别从81.9%、84.2%提高至97.5%和96.7%;PICP和IPP 2种设施对于TP的去除效果均较好,其总污染负荷控制率分别为82.5%、86.2%。统计结果显示,新型透水铺装IPP可明显减少NO^-₃-N、TN、TSS、COD污染物的排放,从而有效缓解雨水径流导...     

光纤传感技术在雨水径流监测中的应用

鉴于海绵城市建设中海绵设施效能监测不足、手段复杂且精度低的问题,将光纤传感技术应用于海绵城市透水铺装中,以光纤光栅温度传感器为监测手段,以外界量改变引发透水面层上下铺设传感器输出波长信号变化为基本原理,得出雨水渗透速率,并以此为核心指标。以湖北省暴雨资料为基础,模拟不同重现期（1,5,10,50,100 a）下不同透水铺装对雨水径流量的削减实验,结合实验数据,建立了雨水渗透速度与透水铺装径流量削减指标的线性拟合关系。结果表明:渗透速度与径流量削减率、产流时刻均有较好相关性（R2>0.93、R2>0.92）。该技术在鄂西地区高铁站成功应用,证明利用渗透速率监测产流时刻与径流量削减率是可行的。     

基于SUSTAIN模拟技术的低影响开发雨水设施规划应用研究

模拟技术是城市低影响开发雨水设施规划设计和研究的重要方法,采用城市暴雨处理及分析集成模型系统(SUSTAIN)对某市A地块的低影响开发雨水设施规划进行研究,分析了低影响开发雨水设施在不同降雨重现期条件下的峰值径流量、径流总量及径流系数的削减效果。结果表明,按照一定比例设置的绿色屋顶、透水铺装、下凹绿地、雨水花园、干草沟等低影响开发雨水设施可以通过下渗和滞蓄作用削减降雨峰值径流量和径流总量,降低了地面径流系数,其中1~5年一遇降雨的径流量和峰值流量基本达到100%削减,10~100年一遇的降雨则有不同程度削减,可显著减少下游渠道和市政管网的外排水量,缓解城市排水系统和河道泄洪的负荷,为城市低影响开发雨水设施的有效利用提供参考。     

极端降雨条件下透水水泥混凝土路面削流除污试验研究

通过试验,对极端降雨条件下透水水泥混凝土路面在削减洪峰流量、径流总量以及去除污染物的效果进行研究。试验表明,在降雨历时60 min,降雨量为110,135,163 mm的情况下,透水水泥混凝土路面削减径流总量为55%~69%,削减洪峰流量为55%~63%;对SS、COD、TN、TP的去除率分别为82%~95%、58%~78%、31%~74%、59%~80%。结果表明,在极端降雨情况下,透水水泥混凝土路面在削流除污方面的效果较好,且与一般降雨条件下的除污效果相近,因此在暴雨情况下,也可产生较好的环境效益,表明其具有气候普适性,是一种良好的海绵城市建设技术。     

透水铺装类型对径流重金属去除效能的影响机制

研究了不同类型透水铺装系统对径流重金属的去除效能和机制.在实验室搭建了3种典型透水铺装系统(陶瓷透水砖、透水沥青和透水混凝土),研究了其对5种常见径流重金属(Cu、Zn、Cd、Mn、Ni)的去除效能和机制,并分析了不同降雨重现期(2,3,5年)对透水铺装系统去除径流重金属的影响.结果 表明:3种透水铺装系统对5种径流重...     

透水混凝土路面对径流水量削减试验

透水混凝土路面作为低影响开发技术之一,对雨洪的管理与控制具有重要作用。对透水混凝土路面对径流的控制作用进行试验,结果表明:基于设计路面和北京降雨参数,降雨历时分别为30,60,120 min时,透水混凝土路面对径流总量的削减率分别达到60%、55%和40%以上,对洪峰流量的削减率分别达到65%、63%和40%以上;降雨重现期从1年增到100年,产流延迟时间从13 min降至5 min。试验表明,透水混凝土路面的雨量径流系数在0.18~0.54,远小于普通混凝土路面的雨量径流系数0.91。结果表明,透水混凝土路面对延迟产流时间、削减径流水量、削减洪峰流量以及降低径流系数具有很好的作用,可以为该低影响开发技术在国内的应用设计提供参考。     

透水混凝土铺装各层对径流污染物的削减试验研究

通过使用人工模拟降雨装置和路面装置,试验研究了径流污染物在透水混凝土路面各结构层的去除情况。结果表明,透水混凝土面层和多孔隙水泥稳定基层对污染物的去除率分别为30%~50%、15%~30%,而级配碎石基层对污染物的去除率不足10%。据分析主要原因为透水混凝土面层和多孔隙水泥稳定基层为多孔介质,并含有水泥,由于水泥自身特性,污染物通过截留过滤、物理和化学吸附以及生物作用被去除。通过阐明各结构层除污的情况为透水混凝土的应用提供了理论依据。     

EDTA-enhanced phytoremediation of lead contaminated soil by Bidens maximowicziana

Phytoremediation is a potential cleanup technology for the removal of heavy metals from contaminated soils.Bidens maximowicziana is a new Pb hyperaccumulator,which not only has remarkable tolerance to Pb but also extraordinary accumulation capacity for Pb.The maximum Pb concentration was 1509.3 mg/kg in roots and 2164.7 mg/kg in overground tissues.The Pb distribution order in the B. maximowicziana was:leaf>stem>root.The effect of amendments on phytoremediation was also studied.The mobility of soil Pb and the Pb concentrations in plants were both increased by EDTA application.Compared with CK(control check),EDTA application promoted translocation of Pb to overground parts of the plant.The Pb concentrations in overground parts of plants was increased from 24.23-680.56 mg/kg to 29.07-1905.57 mg/kg.This research demonstrated that B.maximowicziana appeared to be suitable for phytoremediation of Pb contaminated soil,especially,combination with EDTA.     

Distribution and ecological effect of mercury in Laogang landfill, Shanghai, China

Laogang landfill near Shanghai is the largest landfill in China, and receives about 10000 t of daily garbage per day, Samples of topsoil and plants were analyzed to evaluate mercury pollution from the landfill. For topsoil samples, there were significant correlations among total mercury （HgT）, combinative mercury （Hgc） and gaseous mercury （HgG）, and content of total organic carbon （TOC）, but, no significantly relationship was found between Hg content and filling time. Hg content changes in vertical profiles with time showed that the average Hgv of profiles 1992, 1996, and 2000 was similar, but their average HgG was quite different. HgT was significantly correlated with Hgc in profile 1992 and 2000, and Hgv was significantly correlated with Hg6 in profile 1996. HgG/Hgv ratio in profile samples decreased in the order of （HgG,/HgT）1992〉（HgG/HgT）1996〉〉（HgG/HgT）2000. A simple outline of Hg release in landfill could be drawn： with increasing of filling time, degradation undergoes different biodegradation, accordingly, gaseous mercury goes through small, more, and small proportion to total mercury. Distribution of Hg in plants was inhomogeneous, following the order of leaf〉root〉stem. The highest value of leaf may be associated with higher atmospheric Hg from landfill. Ligneous plants （e.g. Phyllostachys glanca, Prunus salicina and Ligustrum lucidum） are capable of enriching more Hg than herbaceous plants.     

Toxic effects of acetochlor, methamidophos and their combination on nifH gene in soil

Toxic effects of two agrochemicals on nifH gene in agricultural black soil were investigated using denaturing gradient gel electrophoresis （DGGE） and sequencing approaches in a microcosm experiment. Changes of soil nifH gene diversity and composition were examined following the application of acetochlor, methamidophos and their combination. Acetochlor reduced the nifH gene diversity （both in gene richness and diversity index values） and caused changes in the nifH gene composition. The effects of acetochlor on nifH gene were strengthened as the concentration of acetochlor increased. Cluster analysis of DGGE banding patterns showed that nifH gene composition which had been affected by low concentration of acetochlor （50 mg/kg） recovered firstly. Methamidophos reduced nifH gene richness that except at 4 weeks. The medium concentration of methamidophos （150 mg/kg） caused the most apparent changes in nifH gene diversity at the first week while the high concentration of methamidophos （250 mg/kg） produced prominent effects on nifH gene diversity in the following weeks. Cluster analysis showed that minimal changes of nifH gene composition were found at 1 week and maximal changes at 4 weeks. Toxic effects of acetochlor and methamidophos combination on nifH gene were also apparent. Different nifH genes （bands） responded differently to the impact of agrochemicals： four individual bands were eliminated by the application of the agrochemicals, five bands became predominant by the stimulation of the agrochemicals, and four bands showed strong resistance to the influence of the agrochemicals. Fifteen prominent bands were partially sequenced, yielding 15 different nifH sequences, which were used for phylogenetic reconstructions. All sequences were affiliated with the alpha- and beta-proteobacteria, showing higher similarity to eight different diazotrophic genera.     

Enzymatic oxidation of aqueous pentachlorophenol

The influence of the nonionic surfactant Tween 80 on pentachlorophenol （PCP） oxidation catalyzed by horseradish peroxidase was studied. The surfactant was tested at concentrations below and above its critical micelle concentration （CMC）. Enhancement of PCP removal was observed at sub-CMCs. The presence of Tween 80 in the reaction mixture reduced enzyme inactivation which occurred through a combination of free radical attack and sorption by precipitated products. A simple first-order model was able to simulate time profiles for enzyme inactivation in the presence or absence of Tween 80. At supra-CMCs, the surfactant caused noticeable reductions in PCP removal, presumably through micelle partitioning of PCP which precluded the hydrophobic PCP molecule from interacting with the enzyme.     

Decomposition of alachlor by ozonation and its mechanism

Decomposition and corresponding mechanism of alachlor, an endocrine disruptor in water by ozonation were investigated. Results showed that alachlor could not be completely mineralized by ozone alone. Many intermediates and final products were formed during the process, including aromatic compounds, aliphatic carboxylic acids, and inorganic ions. In evoluting these products, some of them with weak polarity were qualitatively identified by GC-MS. The information of inorganic ions suggested that the dechlorination was the first and the fastest step in the ozonation of alachlor.     

Arsenic uptake by arbuscular mycorrhizal maize （Zea mays L.） grown in an arsenic-contaminated soil with added phosphorus

The effects of arbuscular mycorrhizal (AM) fungus (Glomus mosseae) and phosphorus (P) addition (100 mg/kg soil) on arsenic (As) uptake by maize plants (Zea mays L.) from an As-contaminated soil were examined in a glasshouse experiment.Non-mycorrhizal and zero-P addition controls were included.Plant biomass and concentrations and uptake of As,P,and other nutrients,AM colonization,root lengths,and hyphal length densities were determined.The results indicated that addition of P significantly inhibited root colonization and development of extraradical mycelium.Root length and dry weight both increased markedly with mycorrhizal colonization under the zero-P treatments,but shoot and root biomass of AM plants was depressed by P application.AM fungal inoculation decreased shoot As concentrations when no P was added,and shoot and root As concentrations of AM plants increased 2.6 and 1.4 times with P addition,respectively.Shoot and root uptake of P,Mn,Cu,and Zn increased,but shoot Fe uptake decreased by 44.6%,with inoculation, when P was added.P addition reduced shoot P,Fe,Mn,Cu,and Zn uptake of AM plants,but increased root Fe and Mn uptake of the nonmycorrhizal ones.AM colonization therefore appeared to enhance plant tolerance to As in low P soil,and have some potential for the phytostabilization of As-contaminated soil,however,P application may introduce additional environmental risk by increasing soil As mobility.     

Degradation of metabolites accumulated of benzo[a]pyrene by coupling Penicillium Chrysogenum with KMnO4

Several main metabolites of benzo[a]pyrene （BaP） formed by Penicillium chrysogenum, Benzo[a]pyrene-1,6-quinone （BP 1,6- quinone）, trans-7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene （BP 7,8-diol）, 3-hydroxybenzo[a]pyrene （3-OHBP）, were identified by high-performance liquid chromatography （HPLC）. The three metabolites were liable to be accumulated and were hardly further metabolized because of their toxicity to microorganisms. However, their further degradation was essential for the complete degradation of BaP. To enhance their degradation, two methods, degradation by coupling Penicillium chrysogenum with KMnO4 and degradation only by Penicillium chrysogenum, were compared; Meanwhile, the parameters of degradation in the superior method were optimized. The results showed that （1） the method of coupling Penicillium chrysogenum with KMnO4 was better and was the first method to be used in the degradation of BaP and its metabolites; （2） the metabolite, BP 1,6-quinone was the most liable to be accumulated in pure cultures; （3） the effect of degradation was the best when the concentration of KMnO4 in the cultures was 0.01% （w/v）, concentration of the three compounds was 5 mg/L and pH was 6.2. Based on the experimental results, a novel concept with regard to the bioremediation of BaP-contaminated environment was discussed, considering the influence on environmental toxicity of the accumulated metabolites.     

Impact of atrazine and nitrogen fertilizers on the sorption of chlorotoluron in soil and model sorbents

Sorption of chlorotoluron in ammonium sulfate, urea and atrazine multi-solutes system was investigated by batch experiments. The results showed application of nitrogen fertilizers to the soil could affect the behavior of chlorotoluron. At the same concentration of N, sorption of chlorotoluron decreased as the concentration of atrazine increased on the day 0 and 6 in soil, respectively. The sorption of chlorotoluron increased from 0 to 6 d when soils were preincubated with deionized water, ammonium sulfate and urea solution for 6 d. That indicated incubation time was one of the most important factors for the sorption of chlorotoluron in nitrogen fertilizers treatments. The individual sorption isotherms of chlorotoluron in rubbery polymer and silica were strictly linear in single solute system, but there were competition sorption between pesticides or between pesticides and nitrogen fertilizers. That indicated the sorption taken place by concurrent solid-phase dissolution mechanism and sorption on the interface of water-organic matter or water-mineral matter.     

基于综合水质标识指数和对应分析法的校园河道水质评价

以三峡大学的校园河道求索溪为研究对象,利用综合水质标识指数法确定求索溪水质类别,分析其水质时空变化规律,并利用对应分析法得出求索溪中不同监测点的主要污染因子.研究结果表明:求索溪整体的综合水质标识指数为7.423,整体水质为劣V类(地表水环境质量标准GB 3838-2002)且黑臭.从时间变化来看,求索溪4月份的水质最差,5月份次之,4、5月份所有监测点的水质都劣于V类且黑臭;8月份水质最好,水质为Ⅳ类;从空间分布来看,8个监测点综合水质标识指数均超过6.0,水质为劣V类,其中6号监测点的水质相对最好,监测点3号的水质相对最差;对应分析法得出求索溪的整体水体污染程度受总氮因子的影响最大,其次为总磷.该研究拟为求索溪及类似校园河道的水环境治理研究提供基础依据和参考.     

Effects of chitosan on growth of an aquatic plant (Hydrilla verticillata) in polluted waters with different chemical oxygen demands

Effects of chitosan on a submersed plant, Hydrilla verticillata, were investigated. Results indicated that H. venicillata could prevent ultrastructure phytotoxicities and oxidativereaction from polluted water with high chemical oxygen demand (COD). Superoxide dismutase (SOD) activity and malondialdehyde (MDA) contents in H. verticillata treated with 0.1% chitosan in wastewater increased with high COD (980 mg/L) and decreased with low COD (63 mg/L), respectively. Ultrastructural analysis showed that the stroma and grana of chloroplast basically remained normal. However, plant cells from the control experiment (untreated with chitosan) were vacuolated and the cell interval increased. The relict of protoplast moved to the center, with cells tending to disjoint. Our findings indicate that wastewater with high COD concentration can cause a substantial damage to submersed plant, nevertheless, chitosan probably could alleviate the membrane lipid peroxidization and ultrastructure phytotoxicities, and protect plant cells from stress of high COD concentration polluted water.