Agricultural Non-point Source Pollution in China:Evaluation,Convergence Characteristics and Spatial Effects

In this study,an inventory analysis approach was used to investigate the intensity of agricultural non-point source pollution(ANSP)and its spatial convergence at national and provincial levels in China from 1999 to 2017.On this basis,spatial factors affecting ANSP were explored by constructing a spatial econometric model.The results indicate that:1)The intensity of China's ANSP emission showed an overall upward trend and an obvious spatial difference,with the values being high in the eastern and central regions and relatively low in the western region.2)Significant spatial agglomeration was shown in China's ANSP intensity,and the agglomeration effect was increasing gradually.3)In the convergence analysis,a spatial lag model was found applicable for interpretation of the ANSP intensity,with the convergence rate being accelerated after considering the spatial factors but slower than that of regional economic growth.4)The spatial factors affecting the ANSP intensity are shown to be reduced by improving agricultural infrastructure investment,labor-force quality,and crop production ratio,while the expansion of agricultural economy scale and precipitation and runoff have positive impact on ANSP in the study region.However,agricultural research and development(R&D)investment showed no direct significant effect on the ANSP intensity.Meanwhile,improving the quality of the labor force would significantly reduce the ANSP intensity in the surrounding areas,while the precipitation and runoff would significantly increase the pollution of neighboring regions.This research has laid a theoretical basis for formulation and optimization of ANSP prevention strategies in China and related regions.

Quantitative analyses of relationships between ecotoxicological effects and combined pollution

The responses of wheat Triticum aestivum, rice Oryza sativa, earthworms Eisenia foetida, and prawns Penaeus japonicus to combined acetochlor-Cu, Cd-Zn were studied in hy-droponic and soil-culturing systems using the methods of ecotoxicology. In particular, system-atically quantitative analyses were documented by field experiments. Results showed that ecotoxicological effects under the combined pollution were not only related to chemical proper-ties of pollutants but also dependent on the concentration level of pollutants, in particular on the combination of concentrations of pollutants in ecosystems. Additionally, species of organisms, especially the type of ecosystem, determined the influences. To some extent, biological tissue targets attacked by pollutants were an important factor.

Comprehensive kinetic study on ammonia/ethylene counter-flow diffusion flames:influences of diluents

This study aimed to investigate the effects of ammonia addition on ethylene counter-flow diffusion flames with different diluents on the fuel or oxidizer side,using kinetic analyses.A special emphasis was put on assessing the coupled chemical effects of NH_(3) and CO_(2) on C2H4 combustion chemistry.The chemical effects could be evaluated by comparing fictitious inert NH_(3) or CO_(2) with normal active NH_(3) or CO_(2).The results revealed that the addition of NH_(3) decreased the mole fractions and production rates of key soot precursors,such as acetylene,propynyl,and benzene.When CO_(2) was used as the dilution gas,the coupled chemical effects of NH_(3) and CO_(2) were affected by the chemical effects of CO_(2) to varying degrees.With the oxidizer-side CO_(2) addition,the coupled chemical effects of NH_(3) and CO_(2) reduced the mole fractions of H,O,OH radicals,acetylene,propynyl,and benzene,while the effects differed from the fuel-side CO_(2) addition.The coupled chemical effects of NH_(3) and CO_(2) also promoted the formation of aldehyde contaminants,such as acetaldehyde,to some extent,particularly with CO_(2) addition on the oxidizer side.

An exploration of meteorological effects on PM_(2.5) air quality in several provinces and cities in Vietnam

Linking meteorology and air pollutants is a key challenge.The study investigated meteorological effects on PM_(2.5)concentration using the advanced convergent cross mapping method,utilizing hourly PM_(2.5)concentration and six meteorological factors across eight provinces and cities in Vietnam.Results demonstrated that temperature(ρ=0.30)and radiation(ρ=0.30)produced the highest effects,followed by humidity(ρ=0.28)and wind speed(ρ=0.24),while pressure(ρ=0.22)and wind direction(ρ=0.17)produced the weakest effects on PM_(2.5)concentration.Comparing theρvalues showed that temperature,wind speed,and wind direction had greater impacts on PM_(2.5)concentration during the dry season whereas radiation had a more influence during the wet season;Southern stations experienced larger meteorological effects.Temperature,humidity,pressure,and wind direction had both positive and negative influences on PM_(2.5)concentration,while radiation and wind speed mostly had negative influences.During PM_(2.5)pollution episodes,there wasmore contribution ofmeteorological effects on PM_(2.5)concentration indicated byρvalues.At contaminated levels,humidity(ρ=0.45)was the most dominant factor affecting PM_(2.5)concentration,followed by temperature(ρ=0.41)and radiation(ρ=0.40).Pollution episodes were pointed out to be more prevalent under higher humidity,higher pressure,lower temperature,lower radiation,and lower wind speed.Theρcalculation also revealed that lower temperature,lower radiation,and higher humidity greatly accelerated each other under pollution episodes,further enhancing PM_(2.5)concentration.The findings contributed to the literature on meteorology and air pollution interaction.

Impact of environmental regulations on the efficient control of industrial pollution in China

The continuous progress of industrialization is a fundamental cause of China’s increasingly severe environmental pollution problem.Improving the efficiency of industrial pollution control is an inevitable choice to effectively decrease pollution emissions,thus winning the battle of pollution prevention and control.In this paper,we used the stochastic frontier analysis(SFA)model to measure the provincial efficiency of industrial pollution control based on the input and output data of industrial pollution control of 29 administrative provinces in China from 2000 to 2017.On this basis,a spatial econometric model was used to explore the influence of environmental regulation intensity on the efficiency of industrial pollution control.In addition,the spatial spillover effect of pollution reduction was thoroughly examined.The results show that:(1)The efficiency of industrial pollution control in China has improved year by year,but the overall efficiency is still low,with the average value increasing from 0.165 in 2000 to 0.309 in 2017.Furthermore,there is significant regional heterogeneity with the highest efficiency level in the east and lowest efficiency level in the west.(2)By increasing the financial and material input,the efficiency of industrial pollution control has increased.However,the increase of human input has not been so helpful.(3)The global Moran’s I index is significantly greater than zero,indicating a strong spatial correlation and agglomeration in the efficiency of industrial pollution control,which is reflected in high-high agglomeration in the eastern region and low-low agglomeration in the western region.(4)Stringent environmental regulation has a positive effect on improving the efficiency of industrial pollution control.It also imposes a positive spatial spillover effect,indicating a strategic interaction and coordination of regional pollution control.In line with this,related proposals have been made to optimize the investment structure for environmental pollution control,establish a flow mechanism for the factor market,and strengthen the environmental responsibility awareness of state-owned enterprises.On this basis,we expect to provide a policy for improving the efficiency of industrial pollution control and promoting regional joint pollution control in China.

中国降碳-减污-扩绿-增长协同发展空间关联网络特征及影响因素研究

协同推进降碳-减污-扩绿-增长已成为我国经济社会发展全面绿色转型的必然选择。基于我国30个省份面板数据(不包含港澳台地区以及西藏自治区数据),运用熵值法、耦合协调度模型和社会网络分析方法,分析各省份间降碳-减污-扩绿-增长协同演变趋势及空间关联网络特征。结果表明:①各省份降碳-减污-扩绿-增长协同效应的变化趋势基本一致,但在空间上呈现东部>东北>西部>中部的区域不均衡特征。②降碳-减污-扩绿-增长协同效应呈现以东部地区为核心的复杂空间网络结构,省际间空间关联性呈上升态势,但网络结构稳定性还有待提高。③北京市、天津市和上海市等地区凭借优越区位,在关联网络中处于主导地位,而宁夏回族自治区、黑龙江省和新疆维吾尔自治区等地区对其他地区的影响较小。④北京市、天津市和上海市等地区属于“主受益”板块,浙江省、广东省等地区属于“经纪人板块”,安徽省、江西省和湖北省等地区属于“净溢出”板块。⑤降碳-减污-扩绿-增长协同效应的空间关联网络受多种因素共同影响,人力资本水平、科技投入、市场化水平和数字经济发展均有利于空间关联关系的建立。研究显示,中国降碳-减污-扩绿-增长协同效应存在空间关联性,需进一步加强省份间的绿色合作与交流,共同推动降碳-减污-扩绿-增长协同发展。

水环境微塑料污染现状及处置技术研究进展

微塑料具有粒径小、比表面积大和疏水性强等特点,在水体环境中分布广泛、难以被降解,并且能够作为其他有毒污染物的载体,进一步增强了微塑料的危害性。深入研究微塑料的危害及其分析、处理途径是有效控制微塑料污染的关键。针对水环境微塑料污染这一热点问题,文章介绍了水环境中微塑料的污染现状和生物效应,阐述了微塑料的分析鉴定方法,分析了水体微塑料常规和新兴去除技术的优势及潜在问题。并进一步探讨了未来水环境中微塑料研究的前景,为水环境中微塑料的去除与污染控制研究提供参考与指导。

大气污染物和温室气体“两单融合”发展分析与建议——助力减污降碳协同增效

为协同推进降碳、减污、扩绿、增长,助力碳达峰、碳中和,文章研究分析了大气污染物排放清单和温室气体排放清单协同融合管理(简称“两单融合”)的必要性和协同增效意义及问题和挑战,分析了国际上先进做法。英国国家大气排放清单由温室气体排放清单和大气污染物排放清单两部分统一组成,涵盖了污染物和温室气体排放数据,由统一机构按统一体系编制和维护,并集成到一个信息平台,德国也类似英国。充分借鉴国际经验,完善“两单融合”相关政策法规制度和技术指南体系,统筹规划、一次性信息采集、统一计算分析和清单编制,开始试点示范,将有助于节省人力物力,促进减污降碳协同增效。

生物炭特性及其促进厌氧消化效率的研究进展

厌氧消化是处理污水污泥和有机废弃物的有效方式之一,能够产生丰富的清洁能源。但在实际运行中也存在一些问题,例如消化器不稳定,易出现氨、酸抑制等现象。生物炭作为一种吸附剂被广泛应用在去除废水中有毒金属、有机污染等方面,并且通过加生物炭,可有效缓解酸积累和氨抑制,提高厌氧消化产甲烷能力。分析生物炭的理化性质及其表面特性,探究生物炭提升厌氧消化体系缓冲能力、缓解氨抑制的原理,论述了生物炭在厌氧消化体系中对微生物群落结构的影响。

基于PMF模型的粤西典型流域氨氮污染特征分析

文章以粤西小东江流域2021—2023年为例,采用相关性分析、正定矩阵因子分解模型PMF等方法对氨氮污染源特征开展了研究。结果表明:小东江流域氨氮浓度时空分异特征明显,2021—2023年,时间变化呈“逐年下降,春季高、秋季低,峰值出现在4月”的特点,沿程变化表现为“上游低,中下游高”。氨氮与高锰酸盐指数、总氮、电导率呈显著正相关关系,与溶解氧呈显著负相关关系。山阁氨氮污染来自畜禽养殖源和农村生活源,贡献占比分别为86%和14%;石碧氨氮污染来自城镇生活源、畜禽养殖源和农业种植面源,贡献占比分别为80%、13%和7%。小东江流域应根据上下游氨氮贡献来源差异特征,采取针对性污染治理措施,上游应注重加强畜禽养殖污染治理,补齐农村污水处理能力缺口,下游应着力加强茂名城区城镇生活污染源管控,实现生活污水处理系统提质增效,加强畜禽污染防控及农业种植面源污染治理。该结果可为小东江流域差异化、精细化决策提供依据和支撑。

基于多源卫星遥感的中国城市绿地大气污染削减作用研究:Ⅰ.大气污染颗粒物

颗粒物是城市大气污染的重要来源,对生态环境和人类健康构成严重威胁。文章利用数学模型和多源卫星遥感数据,量化了2000—2020年中国城市绿地对PM_(2.5)和PM 10的削减量,并分析了其时空变化及环境因素的影响。实验结果表明:植被对PM的干沉降作用呈现先波动上升再下降趋势,这种变化是因为地方政策驱动下的大气污染物颗粒物浓度骤降导致的;干沉降作用优势树种依次为:常绿阔叶>落叶阔叶>常绿针叶>落叶针叶,其中阔叶林总体占干沉降总量的89.22%;PM_(2.5)削减量与环境影响因子在时域空间上的相干性要比PM 10更加复杂,解释PM变化的最佳变量为降水。关于城市绿地干沉降作用的结论对城市大气污染防治和城市可持续发展有重要意义。

抚河流域氮磷浓度时空分布特征及污染状况评价

及时掌握抚河流域氮、磷等营养盐浓度时空分布特征,是保障鄱阳湖水环境与水生态安全的关键。基于抚河抚州段干流及主要支流14个国控/省考监测断面近9 a的水质监测数据,研究抚河流域抚州段河流氨氮、总磷浓度的时空分布特征,并利用单因素分析、内梅罗综合污染指数和聚类分析法,对抚河抚州段干支流氨氮、总磷污染状况进行综合评价。结果表明:(1)抚河干流及主要支流断面氨氮、总磷浓度达到Ⅱ类标准比例分别为91.29%和86.19%。(2)抚河流域河流氨氮、总磷浓度年际间变化较小,但年内季节、月际变化较大,氨氮、总磷浓度均在夏季达到最大值。(3)抚河流域上游氨氮、总磷浓度普遍低于中下游地区。(4)抚河干流氨氮、总磷属轻度污染,支流临水、东乡水的氨氮、总磷属重度污染。研究成果对于抚河流域水环境保护和治理具有重要参考价值。

大气污染物质量浓度对黄土高原降水云物理影响研究

针对黄土高原实际降水展开研究,探究大气污染物质量浓度对黄土高原降水情况的影响程度。将黄土高原1990年-2019年共30年的气象数据资料作为实验数据,通过计算提取出黄土高原降水的分布特征,根据实际的大气污染物质量浓度,设定不同的大气污染物质量浓度环境,再计算大气污染物质量浓度与黄土高原降水情况的相关度,并对其进行分析。实验结果显示,大气污染物质量浓度越低,黄土高原的降水时间、降水强度和降水次数越高。黄土高原的降水情况会受到多种因素的影响,其中,大气污染物质量浓度对黄土高原降水情况的物理影响较大。

跨临界CO_(2)内部过冷增压制冷系统性能评价

为了改善商超用CO_(2)制冷系统的性能,提出跨临界CO_(2)内部过冷增压制冷(TCISS)系统,对比了该系统与3种不同CO_(2)增压制冷循环的性能,并通过已有试验数据对其仿真模拟结果进行了验证。为详细分析该系统的现实应用性能,进一步建立经济性和环保性模型,并与R134a/CO_(2)复叠制冷(RCOS)系统进行比较,以哈尔滨、北京、南京、广州城市为例,分析2种系统在不同气候区域的性能。结果表明:当高压压力大于10.5 MPa时,环境温度在5~30℃范围内,TCISS循环比其他3种CO_(2)增压制冷循环的COP都要高;TCISS的初始投资成本比RCOS高24.5%,但其年度运行成本更低;TCISS的全生命周期成本(XLCC)普遍低于RCOS,并且在哈尔滨的XLCC最小,在广州的XLCC最大。在4个不同的城市中,TCISS系统的SO_(2),NOx,PM2.5,PM10的4项污染物排放指标均低于RCOS,其总等效变暖效应降低了21.2%~23.9%。研究结果可为推动TCISS系统的发展和应用提供理论指导。

观音阁水库北台分支输水隧洞工程地质评价及污染影响分析

观音阁水库输水工程对保障本溪市生活饮用水安全,解决本钢、北台钢厂等大型企业用水需求,具有重要意义。在分析北台分支输水隧洞工程地质条件的基础上,对该分洞污染源、污水渗流通道及影响范围开展初步评价,并提出处理建议,可为工程安全运营提供科学依据。

基于不同养殖尾水处理模式下的鱼塘水体中主要污染物削减效果研究

为评估不同养殖尾水处理模式对鱼塘水体中主要污染物的削减效果,选取了广州市的4个养殖鱼塘作为研究对象,分别对养殖初期、中期、末期尾水进行水质监测,并利用主成分分析法提取影响养殖尾水水质的主要污染物。在不同养殖尾水处理模式下,分析了该主要污染物在不同养殖周期中的浓度变化,并探讨了不同养殖尾水处理模式对鱼塘水体的净化成效。研究结果表明,经过处理后的养殖尾水中的氨氮、总磷浓度较处理前均有明显的下降。选取的4种常见养殖尾水处理模式对养殖水体中的主要污染物氨氮、总磷的削减效果显著,净化效果较好。

乡镇企业密集区菜地土壤重金属含量分布特征及生态效应——以东莞市为例

采用现场采样及室内分析方法,研究了东莞市乡镇企业密集区菜地土壤重金属含量分布特征及生态效应。结果表明,与广东省土壤背景值相比,该地区菜地表层土壤Hg、Pb和Cd发生明显累积,西部平原区和中部过渡区污染最为严重,呈现出产业依赖和地域特征。因子分析和聚类分析结果指示,研究区菜地表层土壤中的8种重金属主要有3种不同来源:Ni、Cr、As和Zn以自然源为主,Hg和Pb主要来源于工业及交通运输,农业生产活动对Cu和Cd贡献最大。土壤重金属污染产生的生态效应明显,近40%的蔬菜样品Pb、Cd、Ni、As含量超过国家食品卫生标准。同种蔬菜对不同重金属以及不同品种蔬菜对同一重金属都具有不同的生态效应。生菜、油麦菜和白菜易受Pb污染影响;油麦菜和白菜易受Cd污染影响;菜薹易受As、Ni污染影响。蔬菜Cd、Ni、As超标与土壤重金属污染关系密切,而Pb含量超标以大气污染为主要来源。

TS-35型氨法脱硫工业化试验及其经济性分析

对TS 35型氨法脱硫工艺进行了系统的工业化试验研究 ,该脱硫工艺对原有锅炉参数影响小 ,氨水消耗量少 ,阻力小 ,能耗低 ,脱硫效率可达 80 % ,几乎无废水排放 ,适用于中小型锅炉的脱硫 ,但有可能会加剧锅炉尾部设备的腐蚀。对于大型锅炉 ,必须考虑副产品硫酸铵的销路和价格问题。通过经济性分析 ,得出目前实施的排污收费制度存在一定的弊病 。

制革工业中铬污染及防治

扼要探讨了制革工业中的主要污染源之一———铬对生物的影响及其环境标准 ,并综合介绍了铬的分析方法及其污染防治技术 .

淮河流域水质污染时空变异特征分析

选取淮河流域的82个水质监测站,对各站点的1986—2005年水质监测数据进行统计分析,探讨了全流域内水体污染物浓度变化的时空变异特征,为淮河流域水污染治理、水环境保护以及生态修复提供依据。采用时间序列法分析水体污染物浓度的时间变化规律,应用Mann-Kendall检验法对流域范围内水体污染物浓度变化趋势进行了分析。研究结果表明,淮河流域水质变化主要受到入河排污量、上游来水量、闸坝调控方式以及气候条件等方面因素的影响。蚌埠站的水体污染物浓度多年变化规律表明,1995年是水体污染物浓度变化的转折点,1995年前水体污染物浓度不断恶化,1995年后水体污染物浓度逐渐好转。DO浓度的年内变化主要受到水温的影响,表现为冬季浓度高于夏季浓度;CODMn浓度同时受到闸坝调控方式以及区域来水量的影响,汛期浓度低于非汛期。从全流域的水体污染物浓度变化规律看,有机污染物浓度呈显著上升趋势的河段主要分布在淮北支流上,说明在20世纪90年代后期,虽然流域进入相对丰水期以及进行了大规模的水污染联防工作,淮河流域水质污染得到了一定程度的改善。但在2000年后,随着流域内入河污水量和污染物排放量的增加,淮河流域的水质污染依然严重。