北京市农业面源污染负荷及入河系数估算

采用考虑降雨影响因子的输出系数模型,以实测数据为基础,结合水文资料和GIS技术,估算北京市2013年农业面源污染物总氮、总磷负荷。根据农业面源污染物总氮、总磷负荷与年径流模数的相关关系,计算北京市2013年五大水系农业面源污染物总氮、总磷入河系数。结果表明:2013年北京市农业面源污染物总氮负荷为17 859.586 0 t,总磷负荷为3 089.559 0 t;从污染源类型来看,2013年农业面源污染物总氮、总磷负荷较高的均为农村生活和畜禽养殖,分别占污染物负荷总量的45.9%、27.7%和83.5%、15.4%;2013年潮白河农业面源污染物总氮入河系数最高,永定河农业面源污染物总磷入河系数最高,北运河农业面源总氮和总磷污染负荷最高,分别为12 859.577 5和2 291.547 1 t,其次为潮白河及永定河。     

农田径流氮磷污染负荷的田间施肥控制效应

由施肥不当造成的农田N、P污染物径流输出是农业非点源污染的主要问题。采用模拟实验的方法，研究了不同施肥方法、不同肥料配方对土壤地表径流N、P流失的影响。结果表明，合理而有效的施肥方法可以作为农田地表径流N、P污染的田间控制技术。合理的基肥比例及追肥次数，适当的种植密度及适量的N肥、P肥，既可提高白菜产量，同时又降低径流中N、P的流失量；不同改性肥料配方可以调控农田径流N、P的污染负荷。     

安家沟流域不同土地利用方式下地表径流中COD和TN的污染负荷

为探明黄河流域不同土地利用方式下地表径流中COD和TN污染分布规律,以安家沟流域为研究对象,采用平均浓度模型,对径流来源及其污染负荷进行了分析研究。结果表明:安家沟流域不同土地利用方式下地表径流中7项污染物质量浓度平均超标1.31倍,其中ρ(COD_(Mn))和ρ(TN)分别超标1.78,2.11倍;劣Ⅴ类水质出现的平均频率为23.86%,其中COD_(Mn)和TN平均出现频率分别为28.17%,52.03%;不同土地利用措施受径流量及其拦蓄效率和污染物输出水平的影响,COD_(Mn)和TN两者污染负荷总量主要分布在林地和农地,其单位面积污染负荷以荒坡为最大(2.989kg/hm~2),草地次之(2.937kg/hm~2),林地第三(1.327kg/hm~2),农地最小(0.447kg/hm~2);在坡面到沟道的径流过程中,由于土壤入渗等因子的影响,污染物总量在流域径流过程中具有明显的衰减过程,ρ(COD_(Mn))衰减了40.01%,ρ(TN)衰减了38.33%。研究显示,安家沟流域COD和TN污染在不同土地利用措施之间分异明显,合理规划土地利用方式、加强水土保持措施可有效减轻面源污染的发生。     

流域沟渠植草拦截农田氮磷入河污染的有效性研究

  【目的】  过度施肥与降雨径流的耦合作用使得大量氮磷从农田流失进入河道,导致河湖水体污染。在水土流失严重区,尤其是热带–亚热带集约化农业坡地,土层浅薄、蓄水性差,在降雨条件下所施肥料极易发生径流侵蚀流失,通过沟渠进入下游河湖水体,导致水体污染。如何控制这种水蚀型面源污染物从农田向河湖水体的输送愈来愈受到人们的关注,为此在流域下游沟渠构建植物拦截系统,评价其减少坡面氮磷入河污染的有效性,为水蚀型农田面源污染物的流域防控提供理论依据。  【方法】  本研究在广西客兰水库水源区那辣小流域,选择下游500 m长的沟渠,该沟渠接收流域上游来水并直接输入水库,隔段种植当地优势植物狗牙根[Cynodon dactylon (L.) Pers]和象草(Pennisetum purpureum),以及引种植物香根草[Vetiveria zizanioides (L.) Nash] (于南宁花鸟市场购买香根草籽育苗移栽)。在13次降雨事件下分别采集沟渠入口和出口处的水样进行检测,用以研究面源污染防治效益。  【结果】  与流域上游入口比较,下游植草沟渠输出水体中溶解态总氮(TDN)浓度由17.55 mg/L降至12.43 mg/L,NH₄+-N由1.06 mg/L降至0.73 mg/L,NO₃?-N浓度由15.10 mg/L降至10.92 mg/L,溶解态总磷(TDP)浓度由0.031 mg/L降至0.021 mg/L;植物对降雨事件下流域输入沟渠中的TDN、NH₄+-N、NO₃?-N和TDP平均去除率分别为31.90%、27.92%、29.80%和31.02%。  【结论】  在热带和亚热带集约化径流农业流域,选择连接上游坡地与下游河湖水库的沟渠植草,可以对流域流失氮磷实施有效地拦截和去除,是一个简单、可行、有效的农业面源污染流域防控措施,值得推广应用。     

甘蔗集约化种植区施肥显著增加入河硝态氮污染:基于氮氧同位素的流域示踪

[目的]过量施用肥料会导致土壤养分过剩,在降雨径流冲刷下极易流失进入河湖水体,引起地表水体污染.本研究旨在阐明农区施肥与入河硝态氮污染的关系,为有效防控农业面源污染提供科学依据.[方法]选择广西集约化蔗区客兰水库水源区的那辣流域,应用双稳定同位素(δ15N-NO3–、δ18O-NO3–)示踪技术,确定流域内3个子流域(...     

汉江流域荆门段面源污染负荷时空分布与污染现状评价

[目的]对汉江流域荆门段面源污染负荷时空分布与污染现状进行分析和评价,为汉江水污染的治理提供科学依据。[方法]利用输出系数模型和等标负荷估算法,对汉江流域荆门段的面源污染负荷进行了空间分析和负荷估算,包括总氮(TN)、总磷(TP)、化学需氧量(COD)和氨氮(NH3-N),得出了汉江流域荆门段面源污染负荷及其空间分布状况。[结果]在所有污染源中,农村生活、畜禽养殖、降雨、土地利用和城镇径流是5个主要的面源污染源;该地区各市县总氮和总磷污染负荷与COD和氨氮污染负荷的输出量的排序均表现为:钟祥市沙洋县东宝区掇刀区;各类污染源总氮贡献率排序为:农村生活农业用地畜禽养殖降雨非农业用地;各类污染物总磷贡献率排序为:畜禽养殖农村生活农业用地非农业用地降雨。[结论]总体来说,河流富营养化主要是由于农村污染物未经处理排放或处理措施不当引起的。     

乌鲁木齐市水磨河沿岸土壤重金属污染现状及评价

选择干旱区典型城市河流乌鲁木齐市水磨河为研究区,结合经典统计学与地统计学相关方法理论,研究了乌鲁木齐市水磨河沿岸土壤重金属含量的分布特征及其污染评价。结果表明:水磨河沿岸土壤重金属含量在土层深度上差异较小;从土地利用方式来看,人为活动明显干扰重金属在沿岸土壤分布中的含量变化,重金属元素间的相关关系在一定程度上反映着几种重金属的同源性与差异性;主成分分析表明,Cu和Zn为水磨河沿岸土壤特征重金属元素,且重金属因子负载图表明Cu和Zn含量存在多因素控制;从空间分布来看,水磨河表层土壤重金属含量分布高值点位置基本相似,主要在河流南端(上游硫磺沟附近)并与河道遇水库、遇支流有关,高值点主要集中在青格达湖、塔桥湾水库、九道湾水库和硫磺沟附近;水磨河沿岸不同土层重金属的单因子污染指数平均值均小于1,整体表现为未污染状态;内梅罗综合污染指数分别为1.26(0—20cm),1.20(20—40cm),1.32(40—60cm),介于1.0P≤2.0之间,处于Ⅲ级,为轻度污染;各土层对不同重金属具有较高的承载力,属中容量区,水磨河沿岸整体土壤重金属环境质量良好。综上可知,Cu和Zn是主要的污染重金属元素,重金属污染受到工厂分布、河流改道及水库建设等人为活动影响。综合不同评价结果认为,目前水磨河沿岸土壤处于未受污染或轻度污染状态,环境质量良好。     

施肥与植物的重金属吸收

对施肥及肥料中的离子对植物重金属吸收影响的研究进行了述评，讨论了目前研究中存在的问题并提出了进一步研究的一些设想。     

萩芦溪流域农业面源污染负荷研究

基于输出系数法和等标负荷法对萩芦溪流域农业面源污染负荷进行了研究,选取总氮（ TN）、总磷（ TP）两个重要污染物指标,对流域内各乡镇及主要污染源的TN、TP负荷进行估算,并运用GIS软件Mapinfo绘制专题地图。结果表明,萩芦溪流域各乡镇TN等标排放量为江口镇＞三江口镇＞庄边镇＞新县镇＞萩芦镇＞大洋乡＞白沙镇,主要污染源为农村人口、畜禽养殖和耕地;TP等标排放量为三江口镇＞江口镇＞新县镇＞梧塘镇＞白沙镇＞庄边镇＞萩芦镇,主要污染源为畜禽养殖、农村人口。     

太湖流域苏州片区农业面源污染负荷研究

为了研究农业面源污染来源问题,以太湖流域苏州片区为研究对象,在分析研究区农业产业特点的基础上,展开了以太湖流域种植业、水产养殖业、规模化家禽养殖业为代表的农业面源污染氮磷污染负荷计算研究,并分别进行了氮磷污染负荷实例计算。计算结果表明:2011年苏州市种植业、水产养殖业、畜禽养殖业氮磷类污染物排放量分别为:TN 2 344.12t,TP 123.78t,TN 12 915.72×103kg,TP 2 560.76t,TN 2 348.98t,TP 460.81t。研究认为:氮磷污染物排放量为水产养殖业种植业家禽养殖业,水产养殖业氮磷污染物排放量是种植业、家禽养殖业总和的4倍以上,水产养殖业是太湖流域面源污染的主要来源,为了改善太湖流域水环境,建议减少水产养殖面积和密度,降低氮磷污染物入湖量。     

有机肥施用模式对环水有机蔬菜种植氮磷径流的影响

在水环境敏感区域以有机生产代替常规集约化农业,对保护生态环境、提高水库水质和保障居民饮用水安全具有重要意义。实际生产中,如果为追求产量盲目施用有机肥会增加氮磷径流流失风险。为在保障产量的前提下减少氮磷流失,本研究于昆明松华坝水库集水区,以不施肥(CK)和常规施用化肥(CF)为对照,在有机生产方式下设置不同类型有机肥[牛粪(DMC)、鸡粪(CMC)以及二者与豆饼的混合有机肥(HH)]及用量(与CF处理等氮素投入100%、80%和60%)的有机肥施用模式,共计11个处理(CK、CF、0.6DMC、0.8DMC、DMC、0.6CMC、0.8CMC、CMC、0.6HH、0.8HH、HH),分析其对土壤径流氮磷流失阻控效果和作物产量的影响。研究结果表明,在有机种植方式下,施用有机肥可使施肥初期(0～25d)总氮径流浓度比常规施化肥降低26.3%～73.9%,生育期总氮累积浓度降低32.8%～67.0%。单施牛粪和鸡粪导致径流水总磷浓度比CF提高49.1%和12.3%,施用混合有机肥或减氮施用牛粪和鸡粪总磷浓度则比CF处理降低15.8%～52.5%。氮素投入水平和施肥类型对径流水氮磷浓度、土壤硝态氮和速效磷含量有显著影响。等氮素投入下不同肥料类型的径流水总氮浓度为化肥牛粪混合有机肥鸡粪,总磷浓度为牛粪鸡粪混合有机肥化肥;土壤硝态氮含量为化肥牛粪、鸡粪混合有机肥,速效磷含量为鸡粪牛粪混合有机肥化肥。以60%氮素水平施用有机肥对径流水氮磷累积浓度和土壤硝态氮含量削减效果最佳,但土壤速效磷仍有累积风险。混合有机肥处理的青花菜产量最高,而单施牛粪或鸡粪存在减产风险。综合来看,与常规施用化肥相比, 60%氮素投入加牛粪、鸡粪和豆饼混合有机肥的施肥模式可在产量提高16.7%的前提下,使径流水总氮、硝态氮、氨态氮浓度分别降低66.5%(18.94mg·L~(–1))、67.2%(11.11 mg·L~(–1))和66.2%(6.57 mg·L~(–1)),总磷降低52.5%(0.5 mg·L~(–1)),可作为推荐施肥类型和用量在松华坝流域有机蔬菜生产进行推广。     

Trace metals in roof runoff

In this paper we present the concentration of heavy metals (Cd, Cu, Pb, Zn) in runoff from five different roofs (tar felt, pantiles, asbestos cement, Zn sheet, gravel) during two rainfall events. The heavy metal load of roof runoff is assessed and the different processes influencing the fate of heavy metals on roof surfaces and in roof runoff are discussed. The extent of contamination with heavy metals of runoff from different roofing material has the following sequence: zinc sheet>tar felt>pantiles>asbestos cement>gravel. The hazard of infiltration of roof runoff with respect to heavy metals is discussed by comparison with concentrations in rain.     

肥料重金属含量状况及施肥对土壤和作物重金属富集的影响

本文对肥料中重金属的含量状况以及施肥对土壤和农作物重金属累积影响的研究进展进行了系统分析和总结。过磷酸钙中锌（Zn）、 铜（Cu）、 镉（Cd）、 铅（Pb）含量高于氮肥、 钾肥和三元复合肥,有机-无机复混肥料中的Pb含量高于其他化肥。有机肥如畜禽粪便、 污泥及其堆肥中的重金属含量高于化肥,猪粪中的Cu、 Zn、 砷（As）、 Cd含量明显高于其他有机废弃物,鸡粪中铬（Cr）含量高;污泥和垃圾堆肥中Pb或汞（Hg）含量高。商品有机肥Zn、 Pb和镍（Ni）含量高于堆肥,Hg含量高于畜禽粪便。多数研究表明,氮磷钾配施与不施肥相比土壤Cd和Pb含量增加,施用有机肥比不施肥提高土壤Cu、 Zn、 Pb、 Cd含量。施用化肥对农作物重金属富集的影响不明确,而施用有机肥可提高作物可食部位Cu、 Zn、 Cd、 Pb 的含量,影响大小与有机肥种类、 用量、 土壤类型和pH以及作物种类等有很大关系。在今后的研究中应着重以下几个方面, 1）典型种植体系下土壤重金属的投入/产出平衡; 2）不同种植体系下长期不同施肥措施对土壤重金属含量、 有效性影响的动态趋势; 3）典型种植体系和施肥措施下土壤对重金属的最高承载年限; 4）现有施肥措施下肥料中重金属的最高限量标准。     

长期肥料试验对土壤和水稻微量元素及重金属含量的影响

长期肥料试验会影响土壤中微量元素和重金属状况以及作物对微量元素和重金属的吸收。本文研究了长期的不同施肥处理对土壤、糙米中微量元素Cu、Zn、Fe、Mn和重金属Pb、Cd含量的影响,结果表明:经17a连续施用猪粪及秸秆还田显著增加了土壤Cu、Zn和Cd全量,而土壤Fe、Mn和Pb全量在不同施肥处理间没有显著差异;施肥增加了土壤有效态Cu、Zn和Fe含量,其中施用猪粪及秸秆还田的3个处理显著增加了土壤有效态Cu、Zn和Cd含量,而土壤有效态Pb含量在不同施肥处理间没有显著差异。不同处理糙米Cu、Zn、Fe、Mn和Pb含量变化较小或没有显著性差异,而在3个施猪粪和秸秆还田处理中,糙米Cd含量均超过国家食品卫生标准(>0.2 mg kg-1)。水稻地上部吸收积累Cu、Zn、Fe、Mn、Pb和Cd总量与其地上部生物量呈正相关,土壤Cu、Zn、Cd有效态与全量含量呈极显著相关关系,而糙米中的镉含量与土壤镉含量有较好的相关关系。长期施用畜粪导致土壤Cd污染问题应引起高度重视。     

The effect of long-term mineral fertilization on the status of iron and heavy metals in soddy-podzolic soils

The long-term application of different mineral fertilizers in field experiments conducted at the Dolgoprudnaya and Luberetskaya agrochemical experimental stations and in the Chashnikovo Training and Experimental Soil-Ecological Center of Moscow State University resulted in an increase in the content of nonsilicate iron in soddy-podzolic soils of different texture, compared to the control (unfertilized) soils, which could be caused by an enhancement of the soil weathering. The greatest effect on the soil weathering was observed for nitrogen (ammonium nitrate) and potassium (potassium chloride) fertilizers. Periodic liming decreased the content of the nonsilicate iron minerals. The citrate-dithionite solution extracted 50 to 80% of the total zinc and 37 to 82% of the total strontium from the soil, which were probably bound to the nonsilicate iron compounds. The latter participate in the redistribution of the strontium arriving to the soil with phosphoric fertilizers: the content of the metal passed into the citrate-dithionite extract from the soil treated with simple superphosphate for a long time period and was 1.3 times higher than that extracted from the control soil.     

Changes of heavy metals in soil and wheat grain under long-term environmental impact and fertilization practices in North China

Abstract

We evaluated the effects of long-term fertilization on heavy metals in soil and wheat grain under no-fertilizer control (CK), nitrogen, phosphorus, and potassium fertilizers (NPK), NPK plus straw (NPKS), and NPK plus manure (NPKM) treatments. Total lead (Pb) significantly increased in the CK over the initial soil. All fertilization treatments increased soil total arsenic (As) than CK, and the NPKM increased total cadmium (Cd), copper (Cu), and zinc (Zn) than NPK. All fertilization treatments increased soil available As and Cd than CK, and the NPKM increased available As and chromium (Cr) than NPK. The NPKS decreased grain As, Cd, Cu, and bran Cr, Zn, and Pb; but the NPKM increased grain Cr, Pb, and bran As, and Cu than NPK. Under current manure fertilization systems, the maximum bearing year of soil for As, Cr, Cd, Cu, Zn, and nickel (Ni) was 1136, 2990, 694, 1530, 910, and 1555?years, respectively.     

Remediation of a soil contaminated with heavy metals by immobilizing compounds

The labile fraction of heavy metals (HM) in soils is the most important for toxicity for plants and microorganisms. Thus, it is crucial to reduce this fraction in contaminated soils to decrease the negative effect of HM. In a greenhouse experiment, the effects of several additives on the labile fractions of Zn, Cd, Cu, Ni, and Pb were investigated in a soil contaminated during long‐term sewage‐sludge application. The accumulation of HM was studied in the aboveground biomass of wheat (Triticum aestivum L.). The additives used were the clay minerals Na‐bentonite, Ca‐bentonite, and zeolite; the Fe oxides hematite and goethite; the phosphate fertilizers superphosphate and Novaphos. Wheat was planted three times during 5 months, allowed to grow for 7 w, and harvested. Dry matter and HM content of shoots were determined after each harvest. Soil samples were taken after the first and third harvest, and the NH₄NO₃‐extractable HM contents were determined. After the addition of 2% Na‐bentonite as well as 2% Ca‐bentonite, a strong reduction of the labile HM soil fraction and shoot HM concentration was observed. At the end of the experiment, the labile fraction was reduced due to the addition of Na‐bentonite and Ca‐bentonite by 24% and 31% for Zn, by 37% and 36% for Cd, by 41% and 43% for Cu, by 54% and 61% for Ni, and by 48% and 41% for Pb, respectively. Furthermore, the shoot HM concentrations with the exception of Zn were reduced below the phytotoxicity range. Accordingly, the shoot dry‐matter production was significantly increased. The addition of phosphate fertilizers (notably Novaphos) strongly reduced the bioavailability of Pb for wheat plants. By addition of 0.05% Novaphos, the labile fraction and the shoot concentration of Pb were lowered by 39% and 64%, respectively. However, the addition of Fe oxides and zeolite resulted only in a small reduction in HM bioavailability to wheat plants. Among the studied additives, Na‐bentonite and Ca‐bentonite have the most promising potential to reduce the bioavailability for the studied HM.     

朝天委陵菜的重金属耐性与吸收性研究

利用植物生长室水培试验和温室土培盆栽试验的方法,研究了朝天委陵菜在不同浓度Pb水培条件下和Cu、Zn、Pb、Cd复合污染土壤条件下的重金属耐性和吸收性,结果表明,水培条件下随着处理浓度的增加,朝天委陵菜均生长良好,虽高浓度Pb处理下出现植株矮小、叶渐黄、根系变黑等毒害症状,但植株并未死亡,表明在水培条件下朝天委陵菜对Pb具有极强的耐性;在最高浓度3 600μmol/L Pb处理下地上部和根中Pb浓度达到最大值,分别为947 mg/kg和71 053 mg/kg。在温室土培盆栽条件下,朝天委陵菜在外加Cu、Zn、Pb和Cd分别为200、1 000、1 000和5 mg/kg的土壤上较对照生长受到抑制,地上部Cu、Zn、Pb和Cd浓度分别达到741±164、18 248±2 222、1 543±483和29.4±5.2 mg/kg;外加重金属更高时则导致植株死亡。朝天委陵菜对Pb胁迫和Cu、Zn、Pb、Cd复合污染土壤具有较强的耐受性,可作为重金属尤其是Pb污染土壤的修复植物。     

Long-term dispersal of heavy metals in a catchment affected by historic lead and zinc mining

Purpose

The Matylda catchment, in southern Poland, was polluted by the discharge of mine waters from a lead and zinc mine that inundated parts of a valley floor and caused the accumulation of metal-polluted sediments. After a partial reclamation of the mine site in the early 1980s, polluted sediments continue to accumulate on downstream floodplains and in fishponds. The aim of this study was to reconstruct the changes in metal dispersal during 100?years of mining and during the 40-year post-mining period and to propose a strategy for pollution mitigation in the area.

Materials and methods

Analyses of Cu, Cd, Pb, Zn, Mn, Ca, Mg and Fe concentrations, speciation of heavy metals and mineralogical analyses were undertaken on overbank sediment cores and in stream sediments. Concentrations of the same elements and macro-ions soluble in stream waters were also determined.

Results and discussion

Concentrations of Zn, Cd and Pb in the sediment profiles vary between 40,000 and 55,000, 300 and 600 and 30,000 and 50,000?mg?kg^-1, respectively. Changes of metal concentrations and the stratigraphy of sediments from the floodplains, stream channels and fishponds suggest rapid changes of metal loads migrating downstream during both the mining and post-mining periods. Since the time of mine closure, fine-grained, mine-derived sediments (ca. 12?cm thick) have been the main source of pollution of post-mining sediments and surface waters. Closure of the mine was followed by a relatively short period of rapid redistribution of sediment-associated heavy metals in the stream channel. Since the 1980s, the floodplain and fishponds have received a constant supply of metals. It contrasts with the slow sediment accretion rate and a rapid decrease of metal concentrations in floodplain pools due to dilution by decomposed leaf litter. A fivefold increase of Cd content in waters over the 4.6?km reach of the Matylda stream indicates continuous leaching of this element from the contaminated valley floor.

Conclusions

Unsuccessful mine site rehabilitation is due to leaching of mine-originated sediments dispersed over the valley bottom. However, the rate of metal remobilization over the last 40?years is low because of the small thickness and widespread anoxic conditions that prevail within both recent and mine-originated sediments and the alkaline pH of stream water, which reduces metal mobility. Distribution of the contaminated layer over a large area of the valley bottom precludes cost-efficient catchment rehabilitation.