轨道交通车辆基地的LID布置优化

近年来，极端天气发生频繁，城市化建设急速发展，由于强降雨导致的城市轨道交通内涝，给轨道交通正常运营带来极大的安全隐患，基于雨水管理的海绵城市建设对解决车辆基地径流问题具有重要作用。基于NSGA-Ⅱ构建以径流总量控制率、节点超载总时间和LID工程总成本为目标函数的LID优化布置算法，从模型角度优化LID措施的组合方案及规模，避免情景方案中人工枚举不全面的问题；并以上海市某车辆基地为研究区域，探究区域的LID布设方案。模拟结果表明：耦合SWMM和优化算法可生成一系列兼顾上述三目标的LID布设方案，有效削减了区域雨水径流总量和洪峰流量，提高区域排水能力，为车辆基地的LID方案设计提供技术支持。     

低影响开发对城市内涝节点雨洪控制效果研究——不同降雨特性下的情景模拟

以中国福建省福州市晋安区解放溪流域高密度居民住宅区为例,针对不同降雨重现期、降雨历时和雨峰系数的降雨情景,利用PCSWMM模型模拟该地区的雨洪情况,并运用模型的低影响开发（LID）模块,研究7种不同LID用地布局情景对研究区内涝节点的雨洪控制效果.情景模拟结果表明：在不同降雨情景下,各LID用地布局情景会使节点的洪峰流量减小、积水时间减少、积水深度变小;植被浅沟措施和植被浅沟&绿色屋顶组合措施会使节点SS峰值浓度高于现状用地,其余布设情景下,SS峰值浓度均减小.LID措施对节点流量和水质的控制效果在低降雨重现期和长降雨历时的降雨情景下较为有效.在单个LID布设情景中,渗透铺装措施控制最佳,而组合LID布设情景中,渗透铺装&植被浅沟&绿色屋顶是最佳的组合控制措施.研究结果可为南方城市居民区实施海绵城市建设提供技术支持,并为地方制定相关规范和标准提供参考和借鉴.     

基于元胞自动机的低影响开发对城市内涝削减效果模拟

低影响开发措施是解决城市内涝问题的重要途径。为评估其对城市内涝的防控效果,论文以福建省长汀县县城为研究案例,提出适宜在研究区开展的透水铺装、下凹式绿地、雨水罐等低影响开发措施方案,利用基于元胞自动机模型的城市内涝模型进行模拟,并通过验证发现元胞自动机模型可有效模拟城市内涝过程。对比低影响开发改造前后的内涝情况,结果显示：1）低影响开发措施能使内涝积水总量削减超过50%,暴雨重现期越长对内涝现象的削弱效果越低;2）通过分析改造前后内涝积水区的空间格局及变化特征,可见大部分内涝积水区在改造后积水削减幅度较大,卧龙山北部及汀江干流左岸的积水区内涝情况改善幅度较小;3）低影响开发改造削减效果最好的为积水深度低于0.2 m的区域,其次为积水深度高于0.5 m的区域,对积水深度处于0.2~0.5 m的区域削减效果并不明显。研究表明低影响开发措施可有效控制城市的内涝灾害。     

城市内涝实时监测系统初探

目前城市内涝已成为困扰城市健康发展的难题,本文对内涝的成因和现状进行了总结,提出建立城市内涝实时监测系统的必要性和紧迫性.系统利用布置在道路雨水管道检查井内的终端监测器,获得各监测点在暴雨发生时的实际水深值,并结合当地GIS系统,使各路段的淹没情况实现在计算机上的动态可视.文章重点介绍了该系统在具体建设过程中监测区域的划分和监测点的布置原则,增强了可操作性.系统一方面实时监测城市各点水情,是暴雨时合理调度可用资源,采取有效防内涝措施的重要依据;另外收集各雨水管道负荷现状,为管线改造、损失评估提供参考资料.本系统经济和社会效益显著,应用前景广阔.     

南宁城市内涝分布特征及其监测预警系统应用分析

利用南宁市2009—2017年城市内涝资料及其自动气象站逐小时降雨资料,对城内104例内涝过程进行了时空特征分析,并对39个内涝点进行内涝等级划分;基于多普勒雷达产品、数值预报产品及城市密集自动雨量观测站数据,采用内涝积水模型及内涝风险等级划分资料,研发出精细化到街区的市内涝监测预警和风险评估系统,实现了城市内涝的实时监测、预警及风险预估。该系统运用于2015年5月4日短时强降雨造成的城市内涝过程,验证结果表明:(1)模拟结果与历史描述基本相符,最大积水深度和位置基本一致,表明该系统具备一定的暴雨内涝动态监测预报能力,对提高城市暴雨内涝灾害的监测预警和风险评估起到了一定作用;(2)由于标本数量过少以及缺乏城市最新实际管网数据等信息,对于个别点预警值与实测值存在偏差,在系统运行过程中,部分参数和致灾阀值需进一步调整,比如可以不断增加标本以及更新城市最新实际管网数据等信息;(3)文中使用的是自动气象观测点实况雨量模拟积水状况,积水过程存在一定滞后性,下一步考虑结合雷达估测降水QPE资料,预警时间将大大提前。     

基于SWMM与ArcGIS的城市内涝灾害风险评估研究 ——以南浦岛为例

城市内涝对城市基础设施造成极大损害且危及市民人身财产安全,需要通过科学评估手段对城市内涝进行风险评估,是防灾减灾工作中的重要一环.以SWMM模拟四种不同设计雨情下广州市南浦岛内的积水状况,利用ArcGIS进行数据分析、功能优化及专题图制作,分析致灾因子和受灾区域性质,结合相关规范建立风险评估体系,通过分析危险性和敏感性对南浦岛主排水管网设计工程的风险评估.利用插值分析得到与实际地形地貌相吻合的灾害风险等级分布图,为防灾减灾提供了决策依据.     

基于SWMM模型的城市已建区排水防涝提标改造途径探讨

随着城镇化建设高质量发展,城市排水防涝标准也在逐渐提高,因此,如何实施已建区排水系统的提标改造,是城市有机更新重要建设内容之一。以北京某已建区域为研究对象,提出了针对排水系统的排水能力和内涝防治标准GB 50014—2021《室外排水设计标准》统筹提标改造的方案,并借助于SWMM模型进行了方案优化评估。结果表明:通过海绵城市建设,在80%年径流总量控制率条件下,现状管网的排水能力可由1年一遇提标至2年一遇。在上述方案基础上,通过模拟评估内涝防治重现期(P=20 a)条件下雨水管网的过载情况,进一步提出并比较了调蓄池集中布置和分散布置2种方案,模拟结果表明:调蓄池末端集中布置无法解决上游区域管网的冒溢问题,而调蓄池分散式布置,可有效消除现状冒溢点,实现现状区域的内涝防治标准提高至20年一遇目标。因此,在已建区排水防涝提标改造过程中,根据场地空间条件,可优先考虑采用海绵城市建设与调蓄池分散式布置相结合的方式实现排水防涝提标改造目标。     

基于MIKE URBAN的中心城区内涝预测与评估——以上海市霍山-惠民系统为例

频发的内涝事件给城市雨水管理带来了极大的挑战,科学的管理决策广泛借助于模型进行评估。MIKE URBAN具有所需数据少,建模与运行简单,精准等优点,在发达国家已经得到广泛的应用。然而我国中心城区(老城区)的地面硬质化率高,排水管网复杂、建模数据较少等情况突出,运用数学模型对内涝进行预测评估的经验相对欠缺。本文将MIKE URBAN应用于上海市中心城区的霍山-惠民排水系统,在多种降雨强度和降雨历时工况下,对系统管网改造方案中的瓶颈节点、管网超负荷运行以及内涝风险情况进行预测分析,指出在管网设计重现期内,扩增管径可作为缓解城市内涝的可行性措施。而解决城市内涝的根本途径是从源头控制径流产生量,恢复城市良性水文循环。研究结果为预测其他中心城区排水管网的改造评估提供了借鉴。     

气候变化背景下上海地下空间的SWOT模型分析

为加强沿海大都市上海的地下空间的安全应对措施,减少气候变化隐患,文章介绍了上海地下空间发展现状;通过滑动平均法对上海气温和降水2个主要气象要素进行分析以了解气候变化背景并探讨了极端气象灾害和海平面上升情况;利用SWOT分析法剖析了上海地下空间内在属性的优势和劣势及面对气候变化的机会和威胁因素。结果表明:地下空间的开发利用能够提高土地利用率、改善生态环境,并具有一定的防护性和热稳定性的内在优势,但其封闭性、不可逆性及救援力量到位限制使其也存在劣势。地下空间一定程度上提高了能效,对于减缓气候变化意义重大,并在防御大风等恶劣天气事件时表现出一定的适应性,而暴雨内涝、海平面上升尤其威胁上海地下空间的安全。     

合流制溢流控制系统的多目标优化

在城镇合流制溢流（CSO）污染控制系统的规划建设过程中,提高CSO削减率的同时降低建设成本一直受到规划建设决策者的广泛关注。针对CSO控制系统优化问题,利用Matlab、Python和SWMM模型建立了CSO控制系统建设成本与CSO削减率的多目标优化模型,借助非支配排序遗传算法（NSGA-Ⅱ）对实例求解得出一系列Pareto解集,并进一步为决策者提供多套选择方案。分析结果表明:在3年一遇设计降雨条件下,优化结果中源头LID设施、末端合流制调蓄池与中途截流管网改造的建设成本占比依次降低,其中末端合流制调蓄池的CSO削减率贡献最高,源头LID设施次之,中途截流管网改造最低。     

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.     

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.     

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.     

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.     

Effects of two sludge application on fractionation and phytotoxicity of zinc and copper in the soil

The potential harm of heavy metals is a primary concern in application of sludge to the agricultural land. A pot experiment was conducted to evaluate the effect of two sludges on fractionation of Zn and Cu in soil and their phytotoxicity to pakchoi. The loamy soil was mixed with 0%, 20%, 40%, 60% and 80% (by weight) of digested sewage sludge (SS) and composted sludge (SC). The additions of both sludges caused a significant raise in all fractions, resulting in that exchangeable (EXCH) and organic bound (OM) became predominance of Zn and organic bound Cu occupied the largest portion. There was more available amount of Zn and Cu in SS treatments than SC treatments. During the pot experiment, the concentration of Zn in EXCH, carbonate (CAR) and OM and Cu in EXCH and OM fractions decreased in all treatments, so their bioavailability reduced. Germination rate and plant biomass decreased when the addition rate was high and the best yield appeared in 20% mixtures at the harvest of pakchoi. The two sludges increased tissue contents of Zn and Cu especially in the SS treatments. Zn in pakchoi was not only in relationship to ΔEXCH and ΔCAR forms but also in ΔOM forms in the sludge-soil mixtures. Tissue content of Cu in pakchoi grown on SC-soils could not be predicted by ΔEXCH. These correlation rates between Zn and Cu accumulation in pakchoi and variation of different fractions increased with time, which might indicate that sludges represented stronger impacts on the plant in long-term land application.     

Intraspecific differences in effects of co-contamination of cadmium and

A hydroponic experiment was carried out to study intraspecific differences in the effects of different concentrations of cadmium (Cd)(0-10 mg/L) and arsenate (As(V)) (0-8 mg/L) on the growth parameters and accumulation of Cd and As in six wheat varieties Jing-9428, Duokang-1, Jingdong-11, Jing-411, Jingdong-8 and Zhongmai-8. The endpoints of wheat seedlings, including seed germination,biomass, root length and shoot height, decreased with increasing the Cd and As concentrations. Significant differences in seed germination, biomass, root length, shoot height and the accumulation of Cd and As were observed between the treatments and among the varieties (p ＜ 0.05). The lethal dosage 50% were about 20, 80, 60, 60, 80 and 20 mg As/L for Jing-9428, Duokang-1, Jingdong-11,Jing-411, Jingdong-8 and Zhongmai-8, respectively, and the corresponding values for Cd were about 30, 80, 20, 40, 60 and 10 mg Cd/L, respectively. Among the six varieties, Duokang-1 was found to be the most resistant to Cd and As toxicity, and Zhongmai-8 was the most sensitive to Cd and As co-contamination. The resistance of the six varieties was found dependant on the seedling uptake of Cd and As. Duokang-1 was the most suitable for cultivation in Cd and As co-contaminated soils.     

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

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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.     

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.