太湖流域农田生产-畜禽养殖系统氮素流动特征

为应对太湖严峻的水体富营养化现状,从源头上降低面源污染负荷,基于物质流分析法与质量守恒原理,研究了常熟市辛庄镇农田生产-畜禽养殖系统的氮素流动通量、流动效率及环境负荷,并用实测值进行了参数校正. 结果表明:2000—2012年,辛庄镇农田生产子系统的单位面积氮素流动通量呈下降趋势,而畜禽养殖子系统的单位面积氮素流动通量则在42.5~50.9 kg/hm2范围内持续波动. 氮素利用率与氮素循环利用率均较低,氮素环境损失率较高,系统损失的氮素中有54.5%进入周围水体. 2000年以来,作物种植与畜禽养殖对辛庄镇环境氮负荷的贡献率分别在38.8%~50.2%与25.4%~35.8%之间波动. 辛庄镇农田施氮量为310.8 kg/hm2,人畜排泄氮量为61.1 kg/hm2,分别远高于全国平均值(197.2和18.6 kg/hm2). 过量施用化学氮肥与畜禽粪便的大量排放是辛庄镇环境氮负荷加重的主要原因. 辛庄镇高投入高产出的农业生产方式加大了太湖水环境修复的难度. 建议调整作物种植与畜禽养殖结构,推广科学施肥与生态养殖,将农田生产与畜禽养殖结合形成产业链,以此减轻氮素环境负荷.      

基于GIS的安徽省耕地畜禽养殖废弃物氮负荷估算及污染潜势研究

利用2012年安徽省各县市区的畜禽养殖统计数据及耕地面积,估算了安徽省畜禽养殖废弃物氮负荷,并利用德尔菲法和层次分析法确定了安徽省耕地畜禽养殖废弃物氮养分污染潜势评价的影响因素及权重,在此基础上,利用GIS空间分析技术对安徽省耕地畜禽养殖废弃物氮养分污染潜势进行了评价分析。结果表明,2012年安徽省的耕地畜禽养殖废弃物氮负荷分布很不均匀,最大值为217.08kg/hm~2,最小值24.27kg/hm~2,平均值为81.99kg/hm~2。绝大部分县市区都未超过170kg/hm~2的限量标准,但太湖县、歙县、砀山县和宁国市分别达到了217.08、212.76、197.82和192.95kg/hm~2。从空间特征看,安徽省各县市区耕地畜禽养殖废弃物氮养分污染潜势评价结果差异较大,大部分区域都属于一般等级以下,污染潜势高的区域主要分布在安徽省的东南部及西部的山地丘陵区,主要包括宁国市、歙县和太湖县,污染潜势较高的区域有长丰县、休宁县、绩溪县、黄山市市辖区、金寨县、岳西县、明光县及潜山县的部分区域。     

规模化畜禽养殖业零排放模式探究

针对中国畜禽养殖业污染日益严重的现状,在分析现阶段中国规模化畜禽养殖业污染治理现状的基础上,提出运用循环经济的理论,因地制宜的采取污染物减排措施.分别从废水、粪便资源化利用以及病死猪的无害化处理三个角度分析了规模化畜禽养殖业的零排放模式,加快推进了生态环境治理体系和治理能力的现代化,从而实现资源整合,提高畜禽养殖废弃物处理设备的利用效率,将污染物变成可再生的资源,为规模化畜禽养殖业污染物处理实现零排放及循环利用提供参考.     

Determinations of hexabromocyclododecane (HBCD) isomers in channel catfish, crayfish, hen eggs and fish feeds from China by isotopic dilution LC-MS/MS

HBCD is widely used brominated flame retardant, which is increasingly reported in the environment. A new isotopic dilution LC-MS/MS method was developed to determine three HBCD isomers, α-, β- and γ-HBCD in channel catfish, crayfish, hen eggs and fish feeds in this study, and especially for the first time HBCD isomers composition in crayfish, hen eggs and fish feeds. Soxhlet extractor and GPC cleanup were used, some important steps and crucial parameters were modified and intensified compared with other literatures, and LC and MS/MS conditions were optimized. The limits of quantitation values of 0.01, 0.005 and 0.005 ng g⁻¹ wet weight in channel catfish and crayfish were calculated for three HBCD isomers, respectively; so did 0.1, 0.05 and 0.05 ng g⁻¹ wet weight in eggs and 0.2, 0.1, 0.1 ng g⁻¹ wet weight in fish feeds. Recoveries of α-HBCD, β-HBCD and γ-HBCD were ranged between 75% and 105% for these productions at medium and high-level spiked samples, and between 60% and 85% at low-level spiked samples. The established methods were therefore suitable for the determinations of three HBCD isomers in these productions at trace contamination levels. Moreover, thirty commercial channel catfish, crayfish, hen eggs and fish feeds samples collected from local markets, and thirty home-produced hen eggs from private owners in Hubei province of China, were analyzed to determine whether these productions were contaminated by HBCD. Using the established methods, HBCD emerged in 4 of 30 fish feeds and 3 of 30 home-produced eggs, and in low-ng g⁻¹ wet weight.     

Costs and Benefits of the Presence of Leopards to the Sport‐Hunting Industry and Local Communities in Niassa National Reserve,Mozambique

Sport hunting is often proposed as a tool to support the conservation of large carnivores. However, it is challenging to provide tangible economic benefits from this activity as an incentive for local people to conserve carnivores. We assessed economic gains from sport hunting and poaching of leopards (Panthera pardus), costs of leopard depredation of livestock, and attitudes of people toward leopards in Niassa National Reserve, Mozambique. We sent questionnaires to hunting concessionaires (n = 8) to investigate the economic value of and the relative importance of leopards relative to other key trophy‐hunted species. We asked villagers (n = 158) the number of and prices for leopards poached in the reserve and the number of goats depredated by leopard. Leopards were the mainstay of the hunting industry; a single animal was worth approximately U.S.$24,000. Most safari revenues are retained at national and international levels, but poached leopard are illegally traded locally for small amounts ($83). Leopards depredated 11 goats over 2 years in 2 of 4 surveyed villages resulting in losses of $440 to 6 households. People in these households had negative attitudes toward leopards. Although leopard sport hunting generates larger gross revenues than poaching, illegal hunting provides higher economic benefits for households involved in the activity. Sport‐hunting revenues did not compensate for the economic losses of livestock at the household level. On the basis of our results, we propose that poaching be reduced by increasing the costs of apprehension and that the economic benefits from leopard sport hunting be used to improve community livelihoods and provide incentives not to poach. Costos y Beneficios de la Presencia de Leopardos para la Industria de la Caza Deportiva y las Comunidades Locales en Niassa, Reserva Nacional, Mozambique     

泥石流滩地农业资源化开发与利用——以蒋家沟为例

泥石流滩地是山区宝贵的土地资源，其农业资源化开发与利用对促进当地社会经济发展和生态环境改善具有重要意义。以蒋家沟流域为例，在野外调查、遥感解译和实验分析的基础上，阐述了泥石流滩地农业资源化的原则和依据，建立了人畜 土地载荷平衡模型，分析了滩地开发利用的依据、效益和途径，并探讨了泥石流滩地未来农业资源化的思路和对策。研究结果表明：（1） 建立的人畜 土地载荷平衡模型反映了流域生态环境特征，能有效评价滩地开发利用的生态效益；（2）流域滩地农业资源化每年可产生500多万元的经济效益，除满足全流域6 418人的粮食需求外，还可提供338 t商品粮，是促进当地脱贫致富和社会经济发展的重要途径；（3）泥石流滩地既是宝贵的土地资源又是灾害的场所，其开发与利用可有效缓解山区人地矛盾，具有良好的生态效益，但需要在加强灾害防治和防灾减灾意识的基础上，进行深度农业资源化开发.     

长江三角洲农牧系统结构的区域差异及空间位移研究

调整农业结构，实现农业增效、农民增收农业可持续发展，以确保中国中长期食物安全，是中国目前和未来农业和农村工作的重点。农业结构的调整，必须建立在对系统整体认识的基础上，必须符合系统结构本身的演变规律。为此，作者于1996－1999年，以中国经济发达的长江三角洲农区为例，通过资料调研、专家咨询、农户调查、实地考察和试验等手段。对该区1980－1997年以来71个县市的农业生产进行了全面的调查。利用基于GIS的农牧系统综合评价系统，对长江三角洲农牧系统结构的区域差异和空间布局变化进行了全面分析。结果显示，长江三角洲农牧系统结构存在显著的空间梯度差异，布局上出现了明显的空间位移，农业重心开始向南北推移。棉花、小麦和玉米均向北部集中，生猪和家禽向北部和中部的东北部集中，农业生产呈现出显著的区域性专业化布局格式。     

The effects of soil and Trifolium repens (white clover) on the fate of estrogen

In this study, we investigated the behavior of estrogens in the rhizosphere of white clover (Trifolium repens, clover hereafter) with two different pot tests, using soil and agar as growth media. In a pot test using agar spiked with estrogen, the estrogen concentration in the agar with clover decreased to non-detectable levels within one month, while in the agar without clover, 60% of initially added estrogen remained after one month. The half-lives of estrone (E1) and 17β -estradiol (E2) in the agar with clover were 2.4–3.8 and 13.2 d, respectively. The dissipation of E1 followed first-order rate law, while that of E2 fitted a zero-order reaction, indicating that they had different mechanisms of dissipation from agar. In the soil pot test, the behavior of E1 and E2 was not influenced by clover. An initial rapid decrease in the amount of estrogen extracted by methanol/acetic acid was followed by persistence for 1–3 months, regardless of presence of clover. Moreover, in three weeks E1 and E2 were only partly degraded by microbes extracted from the soil used in the pot test. In this study, abiotic degradation of estrogens and sorption of estrogen to soil, rather than the effects of soil microbes and clover, contributed to the initial rapid dissipation of estrogens in the soil. However, the results of the agar pot test suggested that vegetation such as clover may significantly contribute to removal of estrogens when estrogens in aqueous phase are discharged with surface runoff and preferential flow after heavy rain in agricultural fields, or when present in soils with low estrogen sorptivity.     

固定化活性污泥实现短程硝化反硝化处理畜禽废水

以畜禽废水为处理对象,通过分别控制水力停留时间(HRT)、溶解氧(DO)、pH值、温度和碳氮比(C/N)等影响亚硝化的主要单因子,以使固定化活性污泥颗粒实现短程硝化反硝化反应,在连续流运行模式下进行废水脱氮实验,实验结果表明,单因子HRT为10 h,溶解氧为4 mg/L,pH值为8.5,温度为30℃,碳氮比为10时,对TN和COD的去除率分别为81.98%、93.79%;87.32%、98.35%;83.82%、93.93%;85%、97%;85.37%、97.28%,达到了理想的去除效果。     

北运河流域(北京段)畜禽养殖污染现状及防治对策研究

畜禽养殖业产生的畜禽粪污对空气、土壤、地表水及地下水均会造成污染.调研了北运河流域(北京段)畜禽养殖业现状,分析了其污染空间分布及粪污处理方式,并提出了畜禽养殖存在的主要问题.结合国内外研究及北运河流域(北京段)概况,从布局、粪污处理、资金投入等方面提出了应对措施与建议,为环境管理部门开展畜禽养殖污染防治提供借鉴与参考.