Principal Component Analysis of Major Pollutants Discharge Amount in Major Cities

With the development of industry in China, the emission issues of indus- trial wastewater has got more and more attention. Excessive levels of pollutants in wastewater are urgent problem to be solved. Together with the emissions of do- mestic wastewater, the discharge amount of pollutants has exceeded standard in many cities, which not only pollutes the water resources, but also greatly threatens the environment, and does great harm to people＇s health. The principal component analysis was conducted based on the principal components extracted from the data of major pollutants emission conditions in the wastewater of major cities from the China Statistical Yearbook 2014.

Factor Analysis on Quantity of Discharged Pollutants in Wastewater in Major Cities

The research performed statistical analysis on 186 data concerning the amount of discharged industrial wastewater, the amount of oxygen demand of industrial wastewater, the amount of ammonia and nitrogen discharged from industries, the amount of urban discharged domestic sewage, the amount of daily life chemical oxygen demand, and the amount of domestic ammonia and nitrogen to explore source of pollutants from wastewater and guarantee urban water quality.Factor analysis was then performed with SPSS according to discharge quantity of pollutants. The results should that the major pollutants are from domestic sewage it is expected scientific suggestions be proposed on water quality in our country.

Generation and Discharge of Pollutants in Closed Aquaculture

[Objectives]To gain an in-depth understanding of pollutant generation and discharge from closed aquaculture.[Methods]In 2018,the pollutant generation and discharge coefficients of 7 farming modes in 16 farming bases were calculated and analyzed.[Results]A total of 28 pollutant generation coefficients and 28 pollutant discharge coefficients were obtained,and the generation and discharge of pollutants in closed aquaculture were grasped preliminarily.Compared with the data of the first census of pollutions sources published by the state in 2008,7 kinds of pollution generation coefficients increased,while 14 kinds decreased;and 4 kinds of pollutant discharge coefficients increased,while 17 kinds decreased.[Conclusions]In recent years,the pollutant generation and discharge coefficients of aquaculture show a decreasing trend.

Influence of Rainfall, Discharge, Wave and Alongshore Transport on Microbiological Pollution in Southern California Coastal Beaches

The coastal zone is the significant environmental setting where ocean interfaces land. In addition, it is economically important because of its high residential, commercial and recreational values. Meanwhile, in the United States, public coastal areas are increasingly off-limits due to elevated levels of fecal pollution and other contaminants. This study investigates the effects of rainfall, discharge, wave, and alongshore transport on coastal FIB （fecal indicator bacteria） concentrations at adjacent beaches in Orange County, California, over three years＇ period from October 2001 to September 2004. In order to identify the dominant tempora land spatial patterns of fecal pollutions along the coastal beaches, Empirical Orthogonal Function analysis was utilized for the three-year measurements （n = 39,525） of FIB concentration data from 17 sampling stations. Through the data analysis and the empirical orthogonal function analysis, it was found that the dominant factor effecting coastal FIB concentration is precipitation event and consequent water discharge from Santa Ana River in the area. The Empirical Orthogonal Function analysis revealed the potential non-point FIB sources around northern part of Orange County beaches. In addition, this study confirmed the existing alongshore transport by wave-driven surf zone current and offshore tidal currents.

Predictive Study of Trace Metal Pollution of Gold Panning Sites in Birimian Formations: Case of the Yaouré Furrow (Côte d’Ivoire)

The present study was carried out on small-scale gold mining sites in the Yaouré region of Côte d’Ivoire. This region is geologically representative of the Birimian formations (2.1 Ga) of West Africa. The aim is to determine the potentially toxic trace metals (TMEs) generated by these sites, with a view to preventing possible contamination and/or metal pollution of the waters that provide fish products for local populations. To this end, a sampling campaign was carried out, resulting in the collection of 20 mining waste samples analyzed by X-ray fluorescence spectrometry (XRF) and 10 by X-ray diffractometer (XRD). The XRF analysis detected 06 predominant TMEs: arsenic, chromium, copper, nickel, zinc and vanadium. Statistical analysis was carried out to determine the distributions and correlations between these ETMs. To assess contamination and/or pollution levels, the following indices were calculated on the basis of reference concentrations of upper continental crust MTEs: Enrichment Factor, Geo-accumulation Index, Concentration Factor, Degree of contamination and those related to ecological risks. The results of statistical analyses and indices have shown that arsenic and chromium are the most predominant and can be, depending on the chemical form, potentially more toxic. The results of the DRX analysis show the occurrence of several minerals carrying these two MTEs, especially that of a rare mineral, Stenhuggarite, an arsenic oxide linked to hydrothermal veins. The majority of gold mining operations in West Africa are located in the birimian zone, hence the need for environmental monitoring by the relevant authorities, to prevent potential ecological risks to water and possibly health risks via the food chain.

Effective Removal of Air Pollutions by the Electrical Discharge

The objectives of this study were to understand the effects of different electrical and reactor＇s parameters on the removal efficiency of air pollution and to optimize the parameters to achieve the highest removal efficiency. The surface discharge was applied to dielectric barrier discharge reactors and the voltage, current, frequency and the electrode shape were employed to the reactor as main variables. In general, it has been known that the removal efficiency is decided by the applied power, which is calculated by multiplication of the applied voltage and current. However, the removal efficiency was significantly changed by the composition ratio of the applied voltage and current even though the experimental conditions were not changed with the same applied power. It means that the removal effectiveness should be affected not by the discharge power but by the applied voltage and current separately. From the experimental and statistical analysis, the discharge current was the most important factor to control the removal efficiency regardless of different types of the reactors and the frequency is not the direct function to control the removal rate.

Numerical simulation of the transport and diffusion of dissolved pollutants in the Changjiang (Yangtze) River estuary

Based on a coupled hydrodynamic–ecological model for regional and shelf seas (COHERENS), a three-dimensional baroclinic model for the Changjiang (Yangtze) River estuary and the adjacent sea area was established using the sigma-coordinate in the vertical direction and spherical coordinate in the horizontal direction. In the study, changing-grid technology and the "dry-wet" method were designed to deal with the moving boundary. The minimum water depth limit condition was introduced for numerical simulation stability and to avoid producing negative depths in the shallow water areas. Using the Eulerian transport approaches included in COHERENS for the advection and dispersion of dissolved pollutants, numerical simulation of dissolved pollutant transport and diffusion in the Changjiang River estuary were carried out. The mass centre track of dissolved pollutants released from outlets in the south branch of the Changjiang River estuary water course has the characteristic of reverse current motion in the inner water course and clockwise motion offshore. In the transition area, water transport is a combination of the two types of motion. In a sewage-discharge numerical experiment, it is found that there are mainly two kinds of pollution distribution forms: one is a single nuclear structure and the other is a double nuclear (dinuclear) structure in the turbid zone of the Changjiang River estuary. The rate of expansion of the dissolved pollutant distribution decreased gradually. The results of the numerical experiment indicate that the maximum turbid zone of the Changjiang River estuary is also the zone enriched with pollutants. Backward pollutant flow occurs in the north branch of the estuary, which is similar to the backward salt water flow, and the backward flow of pollutants released upstream is more obvious.

Discharge water temperature assessment of thermal power plantusing remote sensing techniques

Thermal power plants are generally constructed near to sea coast to meet their requirement of coolingwater. The warm water discharge from the thermal power plant is one of the major environmentalconcerns in view of the thermal pollution in the sea water. The temperature limit for the warm waterdischarge from the thermal power plant has to be monitored and controlled. Coastal Gujarat PowerLimited (CGPL) operates (24×7) at an “once-through system” based sea water circulation for powergeneration. The used sea water is then discharged into the sea through an outlet channel. As per environmental norms, the discharge water temperature needs to be maintained below the stipulated “delta”rise (+7 ℃) with respect to ambient sea surface temperature at the inlet. We demonstrate the applicability of thermal remote sensing data in understanding the seasonal and temporal variations of thetemperature difference between the discharge water and the ambient sea water. We used thermal banddata from Landsat-8 satellite imagery to map water surface temperature and create temperature profilesalong the intake and outflow channels (till the sea), to understand the variation of temperature andestimate the “DT” between intake point and various observation points along the outflow. This analysiswas carried out for all 11 months (except June) of the year 2018 to correlate temperature variations withseasonal changes. Tidal conditions during the time of data acquisition were also considered to accountfor the effect of tides on DT. The result shows that the average temperature rise between intake andoutflow are maintained at ~3 ℃ across all the months of 2018, with minor variations in the months ofJuly and August. Further, average temperature drop from outflow to cooling channel (before diaphragm)is seen to be ~2 ℃ across all the months with similar seasonal fluctuations.

Influence on the Ground and Air and Mathematical Description of the High-Voltage Discharge

According to trends of the development the high-voltage devices’ usage and unpredictable weather causes,we find it very important to research electrical discharge from different sources.In our opinion,the most important is to analyze an influence of the atmospheric electricity on the air and ground, create an exact mathematical model of the physical processes,and describe the ecological influence.

Characteristics and applications of diffuse discharge of water electrode in air

Plasma water treatment technology, which aims to produce strong oxidizing reactive particles that act on the gas-liquid interface by way of discharging, is used to treat the organic pollutants that do not degrade easily in water. This paper presents a diffuse-discharge plasma water treatment method, which is realized by constructing a conical air gap through an uneven medium layer. The proposed method uses water as one electrode, and a dielectric barrier discharge electrode is constructed by using an uneven dielectric. The electric field distribution in the discharge space will be uneven, wherein the long gap electric field will have a smaller intensity, while the short one will have a larger intensity. A diffuse glow discharge is formed in the cavity. With this type of plasma water treatment equipment, a methyl orange solution with a concentration of 10 mg 1-1 was treated, and the removal rate was found to reach 88.96%.

Water Quality from the Purification Unit of Thiakhar (Diourbel, Senegal) and Impact of Discharges from Treatment on Water Resources

The installation of a purification unit since 2008 in the village of Thiakhar has improved the physico-chemical and bacteriological quality of the water supply. However about 55% of the raw water comes out of the unit as discharges (approximately 14 m3 per day) highly concentrated in fluoride and chloride ions. Based on historical samples, we find that the volumes of water consumed together with the volumes of water discharged are increasingly significant from year to year. The storage of waste water is carried out in a septic tank connected to a leaking cesspool sink. Significant excesses of these discharges are visible on the site and a flow of concentrate is observed creating a puddle of water that attracts birds and straying cattle. The study describes the following substantial impacts on the natural and human environment: 1) contamination of groundwater, 2) soil salinization 3), impact on flora and fauna, 4) impact on health. The study concludes by identifying measures to mitigate the negative impacts related to the discharges and by proposing alternative solution.

Electrical model and experimental analysis of a double spiral structure surface dielectric barrier discharge

A surface dielectric barrier discharge (SDBD) can discharge at atmospheric pressure and produce a large area of low-temperature plasma.An SDBD plasma reactor based on the double spiral structure is introduced in this paper.To study the discharge mechanism of SDBD,an equivalent circuit model was proposed based on the analysis of the micro-discharge process of SDBD.Matlab/Simulink is used to simulate and compare the voltage-current waves,Lissajous and discharge power with the experimental results.The consistency of the results verifies the validity of the SDBD equivalent circuit model.Maxwell software based on the finite elements method is used to analyze the electrostatic field distribution of the device,which can better explain the relationship between the discharge image and the electrostatic field distribution.The combination of equivalent circuit simulation and electrostatic field simulation can provide better guidance for optimizing a plasma generator.Finally,the device is used to treat PM2.5 and formaldehyde.The test results show that the degradation rate of PM2.5 can reach 78% after 24 min,and formaldehyde is about 31.5% after 10m in of plasma treatment.

Smell reduction and disinfection of textile materials by dielectric barrier discharges

In this paper we present investigations of textile cleaning of cotton fabrics with respect to both, the smell reduction and the disinfection of textile materials. Normal pressure plasma sources on the base of dielectric barrier discharge (DBD) were used for the purification and disinfection of textiles. For gaseous odour components which stick to clothing the results have shown that one can reach an uncritical odour threshold. In the case of disinfection a significant reduction of microorganism population in some of the samples could be noted. In particular a high reactivity is reached, while in parallel with a radiation by ultraviolet light ozone is activated.

税制绿色化与制造业企业绿色创新——基于《环境保护税法》的准自然实验

本文以《环境保护税法》的实施为准自然实验,考察了税制绿色化对制造业企业绿色创新的影响及其作用机制。研究发现,《环境保护税法》实施不仅促进了制造业企业绿色创新数量的提升,也提高了制造业企业的绿色创新质量。异质性分析发现,税制绿色化对非国有、中小规模和传统制造业企业的绿色创新促进作用更为显著。影响机制分析表明,税制绿色化将通过提高企业排污成本、增强地方政府监管动力、提高企业管理者绿色认知等三条作用渠道促进企业绿色创新。本文的研究有利于合理评估环境保护税法的政策效应,研究结论对于进一步推进制造业绿色创新发展提供了决策参考。

水资源污染综合治理措施及其防治效果评估研究

长期的水污染会破坏水环境,造成生态系统的破坏和失衡,影响人类的生产和生活。为此,研究水资源污染综合治理措施并评估防治效果。在分析了水资源污染物的4种主要类型后,从工业生产、市政管理以及工程保障3方面提出相应的治理措施,并使用模糊综合评价法对治理后的效果评价,将评价结果分为5个等级,利用加权平均原则对评价结果定量计算。将所提治理措施应用在某市生态公园调节塘内,经一段时间后检验该塘水质有了明显改善,防治效果评估结果为优秀,证明所提方法在水资源污染治理方面具有可行性。

国内外钢铁工业水污染物排放标准对比及启示

钢铁工业是国民经济重要的基础产业,其用水量大,涉及的生产工艺流程长,排放的污染物种类也较多。为了加强钢铁工业的水污染物排放管理,美国、德国、欧盟等国家(地区)以及世界银行均针对钢铁工业制定了水污染物排放标准,各钢铁工业水污染物排放标准具有各自的特点。梳理了国内外钢铁工业水污染物排放标准,对各标准的适用范围、污染物项目以及排放限值、超标判定要求等主要技术内容进行了对比研究。最后,为了完善我国钢铁工业水污染物排放标准,提出了相关工作建议。

场地土壤镉污染排放清单与溯源——以铜冶炼厂为例

以华东地区某铜冶炼厂为例,采用“四大排放途径”函数定量描述Cd通过“废气沉降、废水排放、固废淋滤、跑冒滴漏”进入土壤的通量.结合AERMOD废气沉降模型,计算废气携带的Cd沉降于场地边界内部和外部的分布,明确各途径对场地内土壤Cd污染的贡献.结果表明,企业在2000~2002年在产期间主要通过废气(1411kg,50.05%)和固废淋滤(1327kg,47.05%)排放Cd,而废水及跑冒滴漏途径影响很小(共81.74kg,2.90%).但所排废气中的Cd沉降于场地内的仅0.68kg(0.05%),场地内土壤Cd主要由固废淋滤途径贡献.空间排放清单显示其主要分布于堆料区和废气处理区等生产区域.研究结果对加强冶炼行业的精细化源头管控有重要指导作用,且本文提出的方法可拓展至其他行业和多种污染物的排放量溯源.

平原河网地区典型旱地面源污染排放系数时间变化特征及影响因素研究

【目的】探明平原河网地区典型旱地离田排放系数的变化特征,为农业面源污染监测管理提供参考。【方法】以上海市崇明岛某典型旱地为研究对象,通过构建水文-水质协同监测系统,对旱地面源污染排放系数进行测算,明确排放系数的时间变化特征,分析排放系数的影响因素。【结果】日尺度下,氮、磷的离田排放系数变化范围分别为2.2~9843.9、0.08~667.0 g/(hm^(2)·d);月尺度下,氮、磷离田排放系数变化范围分别为0.02~17.2、0.001~1.04kg/(hm^(2)·m)。在降水产流事件中,氮离田排放系数与降水历时呈极显著正相关,磷离田排放系数与产流事件的总降水量、平均降水强度、最大小时降水强度极显著正相关。施肥后,氮日排放系数迅速增大,磷日排放系数无明显变化。各时间尺度下,氮排放系数与地表径流不存在显著相关性,磷排放系数与地表径流极显著正相关。【结论】氮、磷离田排放系数的日、月际变化幅度较大,氮离田排放系数易受施肥措施影响,磷离田排放系数则更易受降水和地表径流的影响。

内蒙古河套灌区农田排水污染特征及防控措施

内蒙古河套灌区农田排水引起的面源污染是乌梁素海的首要污染源,具有独特的污染特征及产排路径。通过文献查阅和现场调查,总结了河套灌区灌排系统和制度现状,分析了农田排水污染特征,明确了农田排水污染物的产排路径,并基于农田排水污染的影响因素提出了具体的防控措施。结果显示:1)河套灌区排水系统在农田排水污染物输送方面发挥着至关重要的作用,但近年来排水功能逐渐减弱;2)河套灌区非生长期灌溉用水量占全年用水量的55%~60%,其中每年秋浇洗盐用水量占全年灌溉用水量的1/3,灌溉水资源利用率较低;3)农田排水中化学需氧量、氨氮、总氮等污染物来自河套灌区内部,秋浇期面源污染风险最高;4)河套灌区农业生产活动主要以氮素污染为主,氮素通过土壤下渗并随浅层地下水迁移排放;5)河套灌区灌溉制度、农田内排水过程、排水沟外排水过程是农田排水污染的主要影响因素。针对河套灌区农田排水污染特征、产排路径以及主要影响因素,建议因地制宜采取措施构建综合治理模式,如源头水分调控、排水沟优化以及生态系统过程拦截,以改善乌梁素海流域的水环境。

基于减污降碳和水质目标约束下的黄河干流兰州段城区污水处理厂出水排放限值研究

为科学合理地提出黄河干流兰州段城区污水处理厂出水排放限值,实施精准科学治污,持续改善黄河干流兰州段水环境质量,本文以兰州市城区四座有代表性的污水处理厂(西固、七里河安宁、盐场和雁儿湾污水处理厂)为研究对象,统计四座污水处理厂主要污染物排放浓度、中水回用率、主要污染物去除率及减排效果,分析四座污水处理厂入河排污对黄河干流兰州段水质的影响,梳理污水处理厂运行阶段的碳排放情况.结果表明:(1)兰州市城区四座污水处理厂中水回用率低,介于0.86%~4.66%之间.(2)四座污水处理厂主要污染物的去除率高于国内污水处理厂主要污染物去除率的平均水平,COD、NH_(3)-N年均减排量分别为114584.1、8234.6 t,减排效果明显.(3)在黄河枯水期上游来水水量小、水质接近或超出GB 3838-2002《地表水环境质量标准》Ⅱ类水质目标限值的条件下,叠加区间其他入河排污口的影响,兰州市城区四座污水处理厂均按照设计规模及设计出水水质排污会对下游河段水质造成影响.因此,不能一味地追求出水水质,盲目提标改造,要综合考虑污水处理厂运行过程中的碳排放,在满足受纳水体水质目标前提下,统筹考虑减污降碳.