[Objective]When water leakage accidents like pipe bursts occur in the fire hydrant system of metro intervals,the train control room will directly close the electric valves on the main pipeline remotely,cutting off water supply to the en-tire interval fire hydrant system.This results in significant safe-ty risks for operations.Therefore,it is necessary to study a po-sitioning system for burst pipe points in metro interval fire hy-drant systems.[Method]A solution is proposed to install e-lectromagnetic flowmeters and electric contact pressure gauges on interval fire protection risers to enable precise positioning of burst pipe points.Additionally,through linkage with the BAS(building automation system)for environmental and equipment monitoring,electric valves before and after the pipe burst point can be closed remotely and swiftly,minimizing the impact on the interval fire protection system.The overall architecture of the positioning system for burst pipe points in metro intervals is outlined,comprising three layers:perception layer,network layer,and application layer.[Result & Conclusion]A rapid positioning system for burst pipe points is established,enabling the remote closure of valves before and after the burst point lo-cation.This approach could minimize unprotected sections of the fire hydrant system and the metro service downtime,ensu-ring the metro interval resumes normal operations promptly fol-lowing accidents such as pipe burst.

Complete dehalogenation of halogenated organic pollutants has attracted increasing attention, and electrocatalytic reduction processes are considered prospective technologies due to their high selectivity for carbonhalogen bonds. In this study, a vitamin B12 (VB12) composite electrode was prepared and applied to remove the refractory tribromoacetic acid (TBAA). The reduction process dominated by the VB12 composite electrode showed a degradation efficiency of 55.2 % for 200 mu g/L TBAA within 60 min. Interestingly, UV irradiation considerably increased the efficiency of TBAA for dehalogenation on the VB12 composite electrode. The photoelectrochemical co-catalytic system of a VB12 composite electrode coupled with UV (LP UV 254 nm) could remove 92.2 % of TBAA in 20 min with a rate constant 12 times higher than the VB12-only electrolysis system. The in situ Raman characterization and cyclic voltammetry tests confirmed that the accelerated formation of CoBr bonds and the enhanced atomic H* mediated ability were responsible for improving debromination efficiency. The degradation of TBAA mainly underwent chemical reactions of debromination and mineralization. Acetic acid, formic acid, formaldehyde, and Br- were the major transformation products of TBAA. Acidic conditions favoured TBAA removal in the UV synergistic VB12 electrolytic system, and excellent cycling stability of debromination was obtained in complex aqueous environments (actual bodies of water containing various inorganic and organic matter). This research provides an efficient dehalogenation technology for halogenated micropollutants and novel perspectives on the scientific design of photoelectrochemical dehalogenation processes.

Transport of microplastics (MPs) in coastal zones is influenced not only by their own characteristics, but also by the hydrodynamic conditions and coastal environment. In this article, we first summarized the source, distribution and abundance of MPs in coastal zones around the world through the induction of in-situ observation literature, and then comprehensively reviewed the different transports of MPs in coastal zones, including sedimentation, vertical mixing, resuspension, drift and biofouling. Afterwards, we conducted a comparative analysis of relevant experimental literature, and found that the current experimental research on microplastic transport mainly focused on the settling velocity under static water and the transport distribution under dynamic water. Based on the relevant literature on numerical simulation of microplastic transport in coastal zones, it was also found that the Euler-Lagrange method is the most widely used. The main influencing factor in the Euler method is hydrodynamic, while the Lagrange method and Euler-Lagrange method is hydrodynamic and microplastic particle characteristics. Tides in hydrodynamics are mentioned the most frequently, and the role of turbulence in almost all the literature. The density of MPs is the most influencing factor on transport results, followed by size, while shape is only studied in small-scale models. Some literature has also found that the influence of biofilms is mainly reflected in the changes in the density and size of MPs.

Submerged dam can alter microplastic (MP) transport, and act as a sink for MPs. In this paper, we investigated the interception rates of Polyvinyl chloride (PVC) and Polystyrene (PS) by an artificial submerged dam in a flow flume at first, and found that most of the un-intercepted PVC and PS particles by the dam accumulated behind it under the subcritical (Fr < 1) and turbulent (Re > 500) flows. PVC particles behind the dam mainly concentrated within two dam widths, and the concentration of PS particles decreased with the distance behind the dam lengthening. Then, we performed linear regression fitting and Redundancy Analysis (RDA) between the interception rates collected in 162 experiment tests and environmental factors, including flow velocity, distance to dam and MP concentration. The results showed that the interception rate of PVC and PS particles increased with the distance to dam lengthening, but decreased with the flow velocity and MP concentration heightening. RDA revealed that the interception rate was influenced by flow velocity, distance to dam, and MP concentration from the most to the least. Our findings are believed to contribute to understanding the mechanism of the interception effect of submerged dam on microplastics.

Vitamin B12 (VB12) modified electrodes were prepared for the electrocatalytic reductive debromination of tribromoacetic acid (TBAA). Under galvanostatic conditions set as 5 mmol/L VB12 loading, 20 mmol/L Na2SO4 as electrolyte, 10.0 mA/cm2 current density, pH 3, and 298 K, the degradation efficiency of 200 μg/L TBAA at the VB12 modified electrode could reach 99.9 % after 6 h. The debromination of TBAA followed the first-order kinetic model. The masses of carbon and bromine elements were conserved before and after the reaction, together with the qualitative analysis of the degradation products showed the likely degradation pathways as TBAA→dibromoacetic acid (DBAA)→monobromoacetic acid (MBAA)→acetic acid (AA). ESR detection and quenching experiments confirmed the role of atomic H* in TBAA debromination. In-situ Raman spectroscopy showed that the Co-Br bond was strongly enriched to the electrode surface, accelerating the electron transfer. The H2O dissociation performance and transition states searching catalyzed by VB12 were calculated by Density Functional Theory (DFT) and proved that the composite electrode can effectively promote atomic H* generation. Material characterization and electrochemical performance tests showed that the VB12 modified electrode had excellent stability and atomic H* catalytic activity. The electrocatalytic debromination of TBAA at VB12 modified electrodes mainly involves two mechanisms, direct reduction by electron transfer and indirect reduction by the strongly reducing atom H*. The results provide an efficient way to achieve safe removal of brominated DBPs from drinking water after chlorination and before human consumption.

China is one of the countries with the most serious natural disasters in the world.In order to find out the historical disaster information in China,the attributes of disaster-bearing bodies,and the regional comprehensive disaster reduction and relief capabilities,the State Council requires each province to carry out the first national comprehensive risk census of natural disasters.Nine departments,including the emergency system,have the census tasks.Taking Fenghua district of Ningbo city as an example,its implementation of the census tasks by Fenghua district emergency system is illustrated in this paper.Through risk census,the distribution of major disaster-bearing bodies such as public service facilities,hazardous chemical enterprises and non-coal mining enterprises in Fenghua district is obtained,the information of disaster reduction capacity and historical disaster in key regions is figured out,and then the level of natural disaster prevention and reduction is objectively understood.It will provide natural disaster risk information and scientific decision-making basis for Fenghua District Emergency Management Bureau to effectively carry out natural disaster prevention and emergency management work,and to practically guarantee sustainable economic and social development.

Disinfection byproducts (DBPs) are initially formed in the process of chlorination in the drinking water treatment plants (DWTPs), then further formed in the distribution system due to the presence of residual chlorine and reactive organic matters. However, in China, DBPs are monitored in the effluent from the DWTPs, but less is known about concentrations of DBPs in tap water since they are usually monitored once per half a year. The smart water service system is establishing real-time monitoring of water indices, although DBPs are an urgent need, they are difficult to monitor in real-time due to their diversity and complicated detection methods. If the correlation between DBP concentration and routinely real-time monitored water quality parameters (e.g., pH value, residual chlorine, ammonia) can be evaluated, the concentration of DBPs can be predicted, which will strengthen the control of tap water safety. This article comprehensively assessed the physicochemical parameters and the occurrence of DBP formation in the tap water with an 18-month investigation in Z city (China). DBP formation in tap water of different seasons and different water sources were compared. Based on the relationship between DBPs and physicochemical parameters, linear prediction and nonlinear prediction models of trihalomethanes (THMs), haloacetonitriles (HANs) and haloacetic acids (HAAs) were established, and the accuracy of these models was verified by measured data. Finally, the toxicity and carcinogenic and non-carcinogenic health risk assessment of DBPs in tap water were analyzed.

Based on a one-year field investigation of disinfection by-products (DBPs) in large scale water distribution system (LSWDS), the various characteristics of DBPs together with their correlation with booster chlorination were elaborated through ArcGIS model. Furthermore, the effects of booster chlorination on DBP formation were investigated through simulated experiments. Residual chlorine showed a strong relationship with occurrence of different DBPs in LSWDS, and the yield of DBPs increased significantly after booster chlorination. The simulated chlorination experiments showed that diminution of the ratio of primary to secondary (booster) chlorination dosage, and delaying the secondary chlorine addition reduced the generation of DBPs during water conveyance. The yield concentrations of THMs and HAAs obviously increased after booster chlorination. The correlation between HAAs and chlorine dosage is weaker in the field research than in the simulation experiment while THMs had a positive correlation with the chlorine addition in both field research and simulation experiment.

千岛湖配水工程改善了杭州市的供水水质,水源由钱塘江为主转变为千岛湖外调水源为主.以供水管网末端龙头为调查对象,考察了水源切换前后饮用水中消毒副产物(disinfection by-products,DBPs)的构成特征,并对DBPs存在水平的致癌和非致癌风险进行了对比分析.结果表明供水管网终端龙头水在水源切换后水质明显改善,有机物指标DOC平均值降低13.40％,UV254平均值下降23.53％;龙头水中常检出THMs、HANs和HAAs,由9种减少为8种,DBPs总量减少32.02％;TCM、BDCM、DBCM、DCAN和DCAA中位浓度由5.51、6.63、3.37、1.06、2.96μg·L-1降低为5.31、2.71、1.30、0.61、2.47μg·L-1;同源热水中常检出的DBPs由8种减少为6种,DBPs总量变化不大,HAAs构成比例增加,THMs比例减小.杭州市水源切换前后龙头水中THMs的致癌风险和非致癌风险由27.65×10-6±1.94×10-11和(6.39±0.0256)×10-2降低为10.54×10-6±3.12×10-11 和(3.21±0.0293)×10-2.HAAs致癌风险和非致癌风险分别由8.23×10-6±5.69×10-12和(0.64±0.0013)×10-2降低为4.92×10-6±8.64×10-12和(0.18±0.0041)×10-2;水源切换后THMs致癌风险峰值降低了 42％,DBPs总致癌风险峰值降低了24％;DCAN[和BCAN的细胞毒性由699.72×10-6±2.72×10-8和 220.47×10-6±1.52×10-8降低为 421.72×10-6±6.04×10-8和 127.18×10-6±1.97×10-8,DCAN 和 BCAN 的细胞毒性峰值分别降低了 23％和 10％.

随着极端天气的频繁发生,国内出现小流域洪涝灾害的频率越来越高.为有效减小地区发生洪涝灾害的概率,可对研究地区所在流域进行洪水演进模拟.以海岛城市朱家尖所在流域为研究对象,运用M IKE 11软件搭建一维河网模型,比较分析现状河网条件下,采用不同闸门调度规则的洪水演进过程以及相同调度规则下现状和调整后河网的洪水演进过程.结果表明:通过合理调整河网结构和采用适宜的闸门调度规则,河道洪水水位能得到有效降低.洪水演进模拟可为地区防洪评价及预警工作提供数据支撑,并为管理决策提供参考依据.

A simultaneous analytical method was proposed for the determination of 13 kinds of free amino acids (FAAs) in the aqueous environment by high performance liquid chromatography (HPLC) combined with pre-column derivatization and solid-phase extraction technology. The recoveries for FAAs were between 8.9% and 87.6%, the detection limits of FAAs were in the range of 0.4-2.09 mg/L without enrichment pretreatment, the relative standard deviations were less than 0.6%. The method has been successfully applied to determine low concentrations of FAAs in real water samples. The occurrence of total FAAs in the source water of Hangzhou City ranged from 17.4 to 39.0 mu g/L. Tyr, Lys, and Asp were the dominant species and found with the highest concentrations of 13.4, 13.3, and 6.9 mu g/L, respectively. The conventional water treatment and advanced water treatment with ozonation and activated carbon were not ideal for the removal of FAAs, thus harmful disinfection byproducts might originated in the subsequent chlorination process, including regulated carbonaceous disinfection by-products (C-DBPs) and nitrogenous disinfection by-products (N-DBPs).

水力学在土木、水利类等专业的课程体系中占据重要地位,如何提高水力学教学质量对学习基础构建具有重要意义.本文分析了目前水力学课堂教学存在的问题,结合港口航道与海岸工程专业的实际情况,提出了教学内容、教学模式、实践环节、考核体系等方面的多元化教学改革方案,可为高校水力学课程教学改革提供参考.

[目的]对海岛地区小流域暴雨洪涝灾害进行模拟研究,为该类地区后续开发建设以及防洪排涝治理工作的顺利开展提供技术支撑.[方法]选取浙江省舟山市朱家尖岛为研究对象,根据设计暴雨及设计和校核潮位资料,运用MIKE构建了一维河网模型、二维水动力模型以及MIKE FLOOD耦合计算模型,对比分析两种方案的淹没面积和水深、典型河道断面水位以及重点区域洪水演进过程.[结果]相对于设计暴雨及设计潮位条件下的方案1(94降雨+实测潮位),设计暴雨及校核潮位条件下的方案2(94降雨+极限潮位)在相对高水位时刻淹没面积更大,最大淹没深度更深.[结论]朱家尖流域内河流比降大,汇流时间短,流域调蓄能力差,抵抗暴雨产生的洪涝灾害的能力较弱.特别是暴雨遭受天文大潮时,研究区域受灾程度更重.

Disinfection by-products (DBPs) are defined as important parameters that can deteriorate drinking water quality. The investigation was performed at a laboratory located on a campus in H City of the Zhejiang province. The purpose of the work was to obtain knowledge on the occurrence of DBPs in tap water and boiled water taken from the same pipe, to establish a statistical model to predict DBPs information in tap water based on physicochemical parameters, and to evaluate carcinogenic and non-carcinogenic risks caused by DBPs on a predictional level. The results showed three categories of trihalomethanes (THMs), haloacetonnitrile (HANs), and haloacetic acids (HAAs), including 10 species of disinfection by-products detected in drinking water. The detection rate of target DBPs in tap water was 100% and the concentrations varied in the ranges of 10.12-28.39, 0.98-5.19, and 2.65-7.83 μg·L-1, respectively. In boiled water, bromochloracetonitrile (BCAN) was not detected; the detection rates of tribromomethane(TBM), trichloroacetonitrile (TCAN), and dibromoacetonitrile (DBAN) were 46.43%, 82.14%, and 92.86%, respectively, while the detection rate for other DBPs was 100%. The concentrations of THMs, HANs, and HAAs were in the ranges of 0.60-12.58, 0.02-0.52, and 2.42-5.86 μg·L-1, respectively. After heating, the concentrations of THMs and HANs decreased by 84.22% and 91.45%, respectively. No obvious decrease was found for HAAs. The pH value and specific ultraviolet absorbance (SUVA) had positive correlation with DBPs, whereas residual chlorine and ammonia nitrogen had negative correlation with DBPs. Based on the correlation between the physicochemical parameters and DBPs, a multiple linear regression prediction model of THMs was established, with deviation less than 10.00%, which can be used for the prediction of THMs in tap water. Based on the EPA recommended health risk assessment model, the carcinogenic and non-carcinogenic risks of chlorine disinfection by-products through oral intake were calculated. It was found that the carcinogenic risks caused by the disinfection by-products in the tap and boiled water were (17.24-84.63)×10-6 and (25.49-258.82)×10-7, respectively, and the non-carcinogenic risks were (4.17-50.32)×10-2 and (6.52-107.74)×10-3, respectively. The carcinogenic risk caused mainly by THMs and bromodicloromethane (BDCM) contributed the highest cancer risk in tap water, while for boiled water, trichloromethane (TCM) was found to contribute the highest cancer and non-carcinogenic risk. In boiled water, the reduction of THMs was up to 94.38%, and the cancer risk was reduced by 79.00%.

The occurrence of 18 types of disinfection by-products (DBPs) in two waterworks and the corresponding water supply networks of H City in Zhejiang Province was determined by gas chromatography coupled with electron capture detector (GC-ECD). The correlation between DBPs and organic precursors, and health risks caused by DBPs, were discussed. Results showed that the disinfection by-products detected in drinking water in H City mainly include trihalomethanes (THMs), haloacetic acid (HAAs), haloacetonitrile (HANs) and trichloronitromethane (HNMs), with highest concentrations of THMs followed by HAAs. In the finish water of CX Waterworks and tap water supplied by CX Water works, concentrations of THMs ranged from 7.70 to 32.73μg·L-1and 9.00 to 51.42μg·L-1, respectively, and those of HAAs 3.05 to 21.30μg·L-1 and 6.00 to 26.79μg·L-1, respectively. The THMs in finished water and tap water of TH Waterworks were in the range 8.65-38.76μg·L-1 and 12.09-42.04μg·L-1, respectively, and those of HAAs were 2.42-14.79μg·L-1 and 2.80-33.40μg·L-1, respectively. The DBPs in the finished and tap water of the two waterworks were at lower levels than the limitations regulated by the Sanitary Standard for Drinking Water (GB 5749-2006). The index of dissolved organic carbon (DOC) and UV254 were adopted to describe the organic compounds, and it was found that trichloromethane (TCM) was significantly negatively correlated with DOC and UV254in tap water. Based on the EPA recommended health risk assessment model, the carcinogenic and non-carcinogenic risks of chlorine disinfection by-products in the oral intake route were calculated. It was found that the carcinogenic risks caused by the disinfection by-products in the finished water and tap water of H City were 5.94×10-6-4.76×10-5 and 5.94×10-6-5.56×10-5, respectively, while the non-carcinogenic risks were 0.91×10-2-4.20×10-2 and 1.26×10-2-4.72×10-2, respectively. The carcinogenic risk is mainly from THMs:bromodichloromethane (BDCM) contributes the highest cancer risk, and the non-carcinogenic risk is mainly from TCM.

The abrupt change of temperature and precipitation of Weihe river basin in Baoji section from 1956 to 2008 were analyzed by using cumulative anomaly method,Mann-Kendall method,MTT,Yamamoto method.The results showed that :1)The annual mean temperature sudden increased during 1993-1994.Sudden increased changes in 1993,1993,1986,1987 separately corresponding to spring,summer,autumn and winter temperature,while the summer temperature also has decreased mutation in 1975.2)The annual precipitation has reduced mutation in 1992,while the spring precipitation in 1991 and 2000.Summer precipitation has sudden increased change in 1962.The test results of autumn and winter precipitation were not notable.3)A variety of mutation methods were used to mutation analysis,which shows the time of mutation and the accuracy of mutation time.

The runoff of Weihe river basin in Shaanxi province reduces constantly .The study of runoff variations is particularly important for the development and utilization of water resources in Shaanxi province .With the temperature ,precipitation and runoff data in Shaanxi section of Weihe river basin from 1960 to 2005 ,the variation trend and mutation characteristics are analyzed applying the Kendall rank correlation coefficient , the R/S analysis and the M-K mutation test method .The precipitation and temperature fluctuation in 46 years are obtained .The precipitation and temperature show a decrease trend .The annual extreme value ratio is equal to 5 .57 ,which indicates that the annual runoff variation is obvious . The runoff of four seasons all show s a decrease trend and autumn is the most obvious .The variation trend will continues in the future . Two annual runoff mutations occurred in 1981 and 1993 .The mutation points of four seasons are different . The temperature and runoff have a significant negative correlation , while the precipitation and runoff have a significant positive linear correlation .

According to the 1960-2005 runoff,precipitation and temperature data of hydrological stations and the meteorological stations in the lower reaches of Weihe River,the relationship between runoff and precipitation and temperature was studied by using the impuls response function and variance decomposition method.The results show that precipitation has a positive effect on runoff change,runoff has a weak effect on precipitation change,temperature has a reverse effect on runoff change,runoff has a weak reverse promotion effect on temperature change.The prediction error of runoff mainly comes from the contribution of precipitation,followed by the contribution of self impact and temperature turbulence.

以浙江省某市为研究对象,遵循完整性、指导性、动态性、数据可达性等原则,构建了该市水生态文明城市建设水平评估指标体系;利用模糊聚类循环迭代法科学确定指标权重,并构建了水生态文明城市建设水平评估模型;对该市水生态文明城市建设试点中期进行评估,并针对评估中的薄弱环节提出建议,为后期水生态文明建设工作开展提供借鉴,为政府部门提供决策参考.

Monthly ET monitoring data of Haihe river basin in 2002 similar to 2007 have been obtained by remote sensing, which composites a time series. The Monthly one-dimension ET time series input space was mapped to a high dimension input space for obtaining the data which is adapted to SVM modeling. Using radial kernel function and grid search, the support vector machine of ET series is set up by learning 48 training samples. The model is used to predict 12 samples, the mean squared error of predicting samples is 12.01%, and the deterministic coefficient between predicting values and real values is 0.985. The results show that SVM possesses a stronger generalization ability and higher prediction accuracy and is a useful tool for evapotranspiration time series analysis.