当内涝已成习惯

城市内涝是指由于降雨量超过城市排水能力造成城市积水的现象,2011年入夏以来,中国频遭城市内涝灾害。10月中旬,一场特大暴雨让广州水漫全城。一时间,广州城里住宅进水,街道成河,汽车没顶。古有美女一笑倾城,今有广州乃至全国多个城市的一“涝”倾城。那么我们国家多个城市的排水系统何以会如此经不起考验（7广州逢雨必涝的现状又是什么原因导致的呢？     

南京市城市河道变迁对城市内涝影响研究

在对南京市地理和历史资料和近年来南京城市内涝报道大量收集整理的基础上,以南京市33条城市河流为研究对象,结合实地考察与调研,从城市建设中河流变迁和城市内涝的相关性角度出发,分析南京城市内涝灾害区域特征及其和城市河道变迁的关系,探究南京城市内涝的影响因素,期待相关部门能够注意到城市河道的建设问题,希望能对解决南京内涝灾害有所助益。     

城区叶面尘特性及其多环芳烃含量

用多步连续洗脱方法采集了干线道路路侧和远离道路校园内冬青卫矛叶面积尘,研究了叶面尘的采集方法.测定了2类叶面尘的粒径分布、有机碳含量和多环芳烃含量.结果表明,所测样品上的叶面尘可以在超声条件下4min一步洗脱.路边样品叶面尘积累量几乎是校园样品的2倍.2样品粒径分布基本形态非常相似,包括200μm以上和以下2个组分.后者占绝对优势.但校园内样品叶面尘粒径明显小于路边样品,两者粒径中位数分别为17.2μm和23.1μm.路边样中相对较粗部分显然来自机动车行驶扰动.由于颗粒较细,采自校园叶面尘中多环芳烃含量略高于路边样品.但不同多环芳烃分布谱非常相似.     

基于PPP模式的武汉城市内涝灾害防治体系研究

我国城市化进程正受到城市内涝灾害的困扰,2016年武汉暴雨甚至造成全城瘫痪。为了缓解武汉严峻的内涝形势,根据此次武汉内涝状况,分析了内涝灾害的成因,并探讨了武汉城市内涝灾害防治的新思路,即结合"海绵城市"与"PPP模式"提出了针对武汉市完整的内涝灾害防治体系规划。该体系将生态环境、经济效率和社会效率有机结合,可为城市内涝灾害防治提供依据。     

合流制排水系统溢流调蓄技术研究及应用实例分析

排水系统雨天溢流对受纳水体的污染已日益受到关注。合流制排水系统溢流调蓄技术是控制面源污染．削减污染负荷的一项关键技术。建设调蓄池以减少排江污染负荷是重要的工程措施之一。文章介绍了调蓄池的原理和作用。并结合上海的实际情况，分析阐述了调蓄池的计算方法，为合流制排水系统面源污染控制提供技术支持，并可总结推广应用于上海及其他城市合流制排水系统污染物控制工程。     

常州市排水基础设施安全运行监测平台建设与研究

排水系统是城市重要的基础设施之一，监测其运行状态意义重大。为解决排水系统数据管理、在线监测、业务管理、内涝预警等方面的问题，以常州市为研究对象，深入分析了排水系统现状及问题，并给出了解决方案。基于GIS、物联网、人工智能、数字孪生等技术，提出了排水基础设施安全运行监测技术架构，研发并建成排水基础设施安全运行监测平台。系统上线后，管网养护成本平均降低12%,污水全年低水位运行时间提升10%,一体化调度效率提升50%,实现了设施全生命周期管理、管网全方位监测、内涝高效预警与处置、厂网一体化调度，并有效提高了常州市排水基础设施数字化、智能化监管水平，可为同类城市相关工作提供参考。     

基于心理距离的社区内涝风险感知差异性分析

社区是灾害风险管理最广泛的参与单元,社区居民对内涝灾害的风险感知在灾害风险管理中越来越受到关注.从时间距离、空间距离、概率距离、社会距离4个维度构建了居民对内涝风险的心理距离评价指标体系,从可控度和熟悉度两方面测度居民的灾害风险感知能力,选取了城市老旧社区、校园社区、城中村三种类型社区,通过实地调研收集数据,分析不同类...     

全过程内涝防治体系对缓解城市内涝的效果分析

基于综合流域排水系统模型（Infoworks ICM）,将海绵城市、排水管网系统及城市河网、排涝泵站系统相互耦合,形成了全过程内涝防治系统模型。此耦合模型将内涝产生的源头、过程、末端三个阶段进行耦合评估,弥补了传统内涝防治措施中单一模拟管网或雨水控制系统的不足之处。分别通过模拟现状、完善管网系统、增加雨水控制设施、完善排涝泵站系统4种情景,分析了建立全过程内涝防治系统的优势。模拟结果表明,3种耦合措施在现状系统基础上对城市内涝均有不同程度的缓解,管道排水能力逐步增强,内涝风险区面积分别降低了13.5%、39.4%和86.9%。研究结果表明,单一内涝防治措施不能从根本上解决内涝风险,建立完整的全过程内涝防治体系在实践层面至关重要。     

平原河网城市雨水排水系统弹性评价

随着城市化高速发展,城市排水和内涝的压力日益增大,增强雨水排水系统的“弹性”是城市发展的方向。选择长江三角洲某平原河网城市的某片区为研究对象,基于率定的SWMM模型和已有的研究,从系统内涝积水量和持续时间2个方面的弹性出发,建立雨水排水系统弹性模型。在不同降雨情境下运行模型,分析研究区域的雨水排水系统弹性。结果表明,随着降雨强度增加,系统弹性逐渐减小;系统弹性值和降雨强度之间呈线性负相关。在低重现期条件下,随着降雨强度的增大,弹性值下降幅度较小。重现期越大,系统弹性值下降速率越快。在同一降雨重现期下,随着不透水地面比例的增加,系统弹性逐渐减小。在高重现期和高不透水地面比例情况下,系统弹性值较低;在10年一遇降雨条件下,区域不透水地面比例增加,系统弹性值下降速度最快。将弹性理念引入城市雨水排水系统中,建立反映系统在应对外界环境变化和灾害时的弹性能力评价体系,有助于全面了解雨水排水系统性能,对于雨水排水系统的优化改造以及城市风险管理具有重要意义。     

苏州河成都路泵站初期雨水特性分析与调控措施

本研究以上海市苏州河沿岸成都路合流制排水泵站为例,对排水泵站集水井进水进行了背景值与单场降雨采样监测,结果表明成都路泵站排水系统水质背景值浓度CODcr、BOD5、TN、NH3-N、TP分别是地表v类水环境质量标准的5～10倍;降雨特征对排水系统雨污混水水质有明显影响;在雨量未形成溢流的情况下,没有明显的初期效应发生.     

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.     

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.     

Potential of plant polyphenol oxidases in the decolorization and removal of textile and non-textile dyes

In this study an effort has been made to use plant polyphenol oxidases; potato （Solanum tuberosum） and brinjal （Solanum melongena）, for the treatment of various important dyes used in textile and other industries. The ammonium sulphate fractionated enzyme preparations were used to treat a number of dyes under various experimental conditions. Majority of the treated dyes were maximally decolorized at pH 3.0. Some of the dyes were quickly decolorized whereas others were marginally decolorized. The initial first hour was sufficient for the maximum decolorization of dyes. The rate of decolorization was quite slow on long treatment of dyes. Enhancement in the dye decolorization was noticed on increasing the concentration of enzymes. The complex mixtures of dyes were treated with both preparations of polyphenol oxidases in the buffers of varying pH values. Potato polyphenol oxidase was significantly more effective in decolorizing the dyes to higher extent as compared to the enzyme obtained from brinjal polyphenol oxidase. Decolorization of dyes and their mixtures, followed by the formation of an insoluble precipitate, which could be easily removed simply by centrifugation.     

Removal of heavy metals from sewage sludge by low costing chemical method and recycling in agriculture

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Single and joint effects of pesticides and mercury on soil urease

The influence of two pesticides including chlorimuron-ethyl and furadan and mercury （Hg） on urease activity in 4 soils （meadow burozem and phaeozem） was investigated. The soils were exposed to various concentrations of the two pesticides and Hg individually and simultaneously. Results showed that there was a close relationship between urease activity and organic matter content in soil. Chlorimuron-ethyl and furadan could both activate urease in the 4 soils. The maximum increment of urease activity by chlorimuronethyl was up to 14%-18%. There was almost an equal increase （up to 13%-21%） in the urease activity by furadan. On the contrary, Hg markedly inhibited soil urease activity. A logarithmic equation was used to describe the relationship （P〈0.05） between the concentration of Hg and the activity of soil urease in the 4 tested soils. Semi-effect dose （ED50） values by the stress of Hg based on the inhibition of soil urease in the 4 soils were 88, 5.5, 24 and 20 mg/kg, respectively, according to the calculation of the corresponding equations. The interactive effect of chlorimuron-ethyl or furadan with metal Hg on soil urease was mainly synergic at the highest tested concentrations.     

Isolation and preliminary characterization of a 3-chlorobenzoate degrading bacteria

A study was conducted to compare the diversity of 2-, 3-, and 4-chlorobenzoate degraders in two pristine soils and one contaminated sewage sludge. These samples contained strikingly different populations of mono-chlorobenzoate degraders. Although fewer cultures were isolated in the uncontaminated soils than contaminated one, the ability of microbial populations to mineralize chlorobenzoate was widespread. The 3- and 4-chlorobenzoate degraders were more diverse than the 2-chlorobenzoate degraders. One of the strains isolated from the sewage sludge was obtained. Based on its phenotype, chemotaxonomic properties and 16S rRNA gene, the organism S-7 was classified as Rhodococcus erythropolis. The strain can grow at temperature from 4 to 37℃. It can utilize several （halo）aromatic compounds. Moreover, strain S-7 can grow and use 3-chlorobenzoate as sole carbon source in a temperatures range of 10-30℃ with stoichiometric release of chloride ions. The psychrotolerant ability was significant for bioremediation in low temperature regions. Catechol and chlorocatechol 1,2-dioxygenase activities were present in cell free extracts of the strain, but no （chloro）catechol 2,3- dioxygenase activities was detected. Spectral conversion assays with extracts from R. erythropolis S-7 showed accumulation of a compound with a similar UV spectrum as chloro-cis,cis-muconate from 3-chlorobenzoate. On the basis of these results, we proposed that S-7 degraded 3-chlorobenzoate through the modified ortho-cleave pathway.     

Organochlorine pesticides in soils under different land usage in the Taihu Lake region, China

A field study was conducted in the Taihu Lake region, China in 2004 to reveal the organochlorine pesticide concentrations in soils after the ban of these substances in the year 1983. Thirteen organochlorine pesticides (OCPs) were analyzed in soils from paddy field, tree land and fallow land. Total organochlorine pesticide residues were higher in agricultural soils than in uncultivated fallow land soils. Among all the pesticides, ΣDDX (DDD, DDE and DDT) had the highest concentration for all the soil samples, ranging from 3.10 ng/g to 166.55 ng/g with a mean value of 57.04 ng/g and followed by ΣHCH, ranging from 0.73 ng/g to 60.97 ng/g with a mean value of 24.06 ng/g. Dieldrin, endrin, HCB and α-endosulfan were also found in soils with less than 15 ng/g. Ratios of p,p'-(DDD DDE)/DDT in soils under three land usages were: paddy field ＞ tree land ＞ fallow land, indicating that land usage inlfuenced the degradation of DDT in soils. Ratios of p,p'-(DDD DDE)/DDT ＞1, showing aged residues of DDTs in soils of the Taihu Lake region. The results were discussed with data from a former study that showed very low actual concentrations of HCH and DDT in soils in the Taihu Lake region, but according to the chemical half-lives and their concentrations in soils in 1980s, the concentration of DDT in soils seemed to be underestimated. In any case our data show that the ban on the use of HCH and DDT resulted in a tremendous reduction of these pesticide residues in soils, but there are still high amounts of pesticide residues in soils, which need more remediation processes.     

Sorption of 1-naphthol by plant cuticular fractions

The contribution of aliphatic-rich plant biopolymer to sorption of hydrophobic organic compounds is significantly important because of their preservation and accumulation in the soil environment,but sorption mechanism is still not fully understood.In this study, sorption of 1-naphthol by plant cuticular fractions was examined to better understand the contributions of respective fraction.Toward this end,cuticular materials were isolated from the fruits of tomato by chemical method.The tomato cuticle sheet consisted of waxes (6.5 wt%),cuticular monomer (69.5 wt%),and polysaccharide (24.0 wt%).Isotherms of l-naphthol to the cuticular fractions were nonlinear (N value (0.82-0.90)) at the whole tested concentration ranges.The KodKow ratios for bulk cuticle (TC1),dewaxed cuticle (TC2),cutin (TC4),and desugared cuticle (TC5) were larger than unity,suggested that tomato bulk cuticle and cutin are much powerful solption medium.Sorption capability of cutin (TC4) was 2.4 times higher than the nonsaponifiable fraction (TC3).The 1-naphthol interactions with tomato cuticular materials were governed by both hydrophobic-type interactions and polar (H-bonding) interactions. Removal of the wax and polysaccharide materials from the bulk tomato cuticle caused a significant increase in the sorption ability of the cuticular material.There was a linear negative trend between K_(oc) values and the amount of polysaccharides or fraction's polarities ((N O)/C);while a linear positive relationship between K_(oc) values and the content of cutin monomer (linear R~2=0.993) was observed for present in the cuticular fractions.Predominant sorbent of the hydrophobic organic compounds (HOCs) in the plant cuticular fraction was the cutin monomer,contributing to 91.7% of the total sorption of tomato bulk cuticle.     

Alterations of organ histopathology and metallolhionein mRNA expression in silver barb, Puntius gonionotus during subchronic cadmium exposure

Common silver barb,Puntius gonionotus,exposed to the nominal concentration of 0.06 mg/L Cd for 60 d,were assessed for histopathological alterations(gills,liver and kidney),metal accumulation,and metallothionein(MT)mRNA expression.Fish exhibited pathological symptoms such as hypertrophy and hyperplasia of primary and secondary gill lamellae,vacuolization in hepatocytes,and prominent tubular and glomerular damage in the kidney.In addition,kidney accumulated the highest content of cadmium,more than gills and liver.Expression of MT mRNA was increased in both liver and kidney of treated fish.Hepatic MT levels remained high after fish were removed to Cd-free water.In contrast,MT expression in kidney was peaked after 28 d of treatment and drastically dropped when fish were removed to Cd-free water.The high concentrations of Cd in hepatic tissues indicated an accumulation site or permanent damage on this tissue.     

Seed selections for crystallization of calcium phosphate for phosphorus recovery

Seed induces and promotes the crystallization of calcium phosphate, and acts as carrier of the recovered phosphorus （P）. In order to select suitable seed for P recovery from wastewater, three seeds including Apatite （AP）, Juraperle （JP） and phosphate-modified Juraperle （M-JP） were tested and compared. Batch and fixed-bed column experiments of seeded crystallization of calcium phosphate were undertaken by using synthetic wastewater with 10 mg/L P phosphate. It shows that AP has bad enduring property in the crystallization process, while JP has better performance for multiple uses, and M-JP is a hopeful seed for P recovery by crystallization of calcium phosphate.