湖南省生猪规模养殖环境成本评估

环境成本作为衡量环境污染程度的重要指标,是环境影响的货币化。利用湖南省生猪规模养殖数据,运用产排污系数法,借鉴农业环境成本评估方法,从生猪规模养殖污染物的实物量和价值量两方面建立生猪规模养殖环境成本评估模型,对湖南省生猪规模养殖的环境影响进行评估。结果表明:2010-2014年湖南省生猪规模养殖造成水体污染、大气污染、土壤污染、农作物重金属污染所产生的年环境成本为25.2亿元,年际间呈稳定增长的态势。由于各县市养殖规模、耕地情况等不同,地区间污染程度差异大,污染物排放量呈向养殖优势区域、密集区域发展的趋势。建立健全成本分担机制,多渠道提高养殖户对生猪规模养殖污染环境的认知水平,完善农村金融供给机制以拓宽养殖户融资渠道,有助于对生猪规模养殖环境成本实施控制。     

微生物修复污染土壤的应用研究进展

近年来,土壤受污染程度日益严重,在众多土壤污染修复中,微生物修复是最具发展和应用前景的生物修复技术,具有经济和生态双重优势。为微生物在污染土壤修复中的应用及进一步深入研究提供参考,以土壤中多环芳烃、多氯联苯、农药以及重金属为对象,综合评述了不同土壤污染类型的微生物修复研究进展,重点介绍了降解微生物的种类、修复机理和技术方法,指出当前污染土壤微生物修复存在的问题,并对微生物修复污染土壤进行了展望。     

大冶龙角山矿区农田土壤重金属形态分布及其来源

为研究大冶龙角山矿区某溪流段沿岸农田土壤基本理化性质和重金属分布情况,采用Tessier五步连续提取法提取并测定土壤中Mn、Cu、Zn、Pb、Cr、Ni和Cd 7种重金属的形态与含量,并分析了重金属含量与土壤Fe和S含量之间的相关性。结果表明:所有重金属在大部分取样点总含量均超出湖北省土壤背景值;Cu和Cd总含量超过土壤环境质量三级标准(GB 15618—1995)限值,Zn、Pb、Cr和Ni符合土壤环境质量二级标准;Mn、Cu、Zn、Pb、Ni和Cd均以残渣态和铁锰氧化物结合态为主,Pb、Cr和Cd存在一定比例的可交换态。矿山矿石组分主要为黄铁矿和黄铜矿,且Mn、Cu、Zn、Pb和Cd的铁锰氧化物结合态、残渣态以及总含量的分布均与土壤Fe和S含量分布表现出较好的正相关关系,表明硫化物矿物开采引发了重金属Mn、Cu、Pb、Zn和Cd在该矿区农田土壤中的累积与污染。     

土壤中对硝基酚迁移转化和去除技术研究进展

对硝基酚是一种有毒难降解有机物,在土壤中的来源众多,其主要来源之一就是农业活动中农药的中间代谢。对硝基酚作为新型污染物进入土壤后易被土壤所吸附进而长期蓄积在土壤中对环境造成影响,其降解特征对环境风险的评估具有重要意义。基于国内外的研究进展,综述了对硝基酚的生物毒性、代谢途径和迁移转化过程,并从物理、化学和生物角度出发对对硝基酚的去除技术进行了论述,进而对其污染的修复进行了展望。     

养猪污染治理异位微生物发酵床的设计与应用

异位微生物发酵床是集中处理养猪废弃物的场所,通常建设在传统猪舍的周围。发酵床内铺设垫料,将猪舍的排泄物引导到异位微生物发酵床内,通过翻堆机将排泄物与发酵垫料混合,进行发酵,消纳粪污,消除臭味,实现零排放,生产有机肥。本课题组设计了一种新型异位微生物发酵床,由钢构房、喷淋池和发酵池组成,并配备翻堆机、喷淋机等设备。异位发酵床可适用于各种传统养猪方法的污染治理,具有较高的生态、经济、社会效益。     

Examination of Correlation between Histidine,Sulfur, Cadmium,and Cobalt Absorption by Morus L., Robinia pseudoacacia L., and Populus nigra L.

We investigated the relationship between histidine, sulfur (S), cadmium (Cd), and cobalt (Co) in three hyperaccumulating plants, namely Morus L., Robinia pseudoacacia L., and Populus nigra L. The samples were collected around Gaziantep and Bursa cities because these two cities have more than 1,500,000 populations, in Turkey, as well as they are highly industrialized. Analyses for Cd, Co, and S were done by inductively coupled plasma mass spectrometer (ICP-MS) and for histidine by high-performance liquid chromatography-mass spectrometer (HPLC-MS). Related with role of histidine in detoxification, it was considered that histidine did not bind nickel (Ni) directly in the cytoplasm, but in transport vesicles because metal-rich vesicles had been observed in the cytoplasm of cells of hyperaccumulator plants. The linear correlations were r_his-Cd = 0.70 and r_his-Co = 0.74 for P. nigra L., r_his-Co = 0.52 and r_Co-S = 0.76 for R. pseudoacacia L. It was concluded that P. nigra L. leaves can be considered as hyperaccumulators.     

不同程度重金属污染对水稻土团聚体组成的影响

以太湖地区长期受重金属污染的稻麦轮作条件下的水稻土为研究对象,分别采取水稻收获期和小麦收获期不同重金属污染水平的土壤和临近非污染土壤(对照土壤),利用低能量超声分散分离技术将原状土进行团聚体分级,并结合土壤碳库分析,研究不同程度重金属污染对水稻土团聚体组成的影响。结果表明:随着重金属污染程度的增加,小麦收获期土壤2~0.2 mm与0.2~0.02 mm粒级的团聚体含量呈显著降低趋势,0.02~0.002 mm与0.002 mm粒级团聚体含量显著增加,但这种趋势在水稻收获期表现不显著;重金属污染降低了水稻季团聚体平均重量直径(MWD),从而降低了土壤的团聚程度,但这在小麦季并未表现出显著的降低作用;而小麦季重金属污染对原土及团聚体中有机碳含量没有显著影响,水稻季重金属污染则显著增加了土壤有机碳的含量。这些结果表明不同重金属污染程度对土壤团聚体组成的影响在不同的作物收获期表现不同,这可能与土壤团聚体周转过程受农田水分管理等措施影响有关,尚需深入研究。     

太原小店污灌区农田土壤多环芳烃的污染特征及其来源

[目的]对太原小店污灌区农田土壤多环芳烃(PAHs)的污染特征及来源进行分析,为该区农田土壤环境质量评价及土壤污染防治对策的制定提供科学依据。[方法]采集太原小店污灌区15个表层土壤样品,利用GC/MS分析16种US EPA优控多环芳烃(PAHs)的含量,并对其来源和生态风险进行探讨。[结果]所有样品的16种PAHs均被检出,其检出率为100%。研究区农田土壤中总PAHs的浓度为0.315~7.661μg/g,平均值为3.568μg/g。在组成上,2,3环含量约占总量的64.2%,4环含量约占总量的14.2%,5,6环含量约占总量的21.6%,低环和中环PAHs含量所占的比例较高。根据特征比值法及调查结果判定,农田土壤中PAHs污染来源一方面与灌溉水质及灌溉历史有很大的关系,另一方面,主要通过燃煤或化石燃料产生的PAHs在大气干湿沉降和风力输送作用下进入到土壤环境中。[结论]与国内外其他地区的相关研究比较,小店污灌区农田土壤PAHs含量处于中高等污染水平。依据Maliszewska-Kordybach建议的分级标准评价,该区域所有采样点PAHs总量均超标;但基于我国《土壤环境质量标准(征求意见稿)(GB15618-2008)》提出的16种多PAHs污染物总量的农业用地标准值,该区域均未超出此标准。     

基于输出系数模型的南四湖流域非点源污染输出风险评估

[目的]探究非点源污染物N、P输出风险在不同子流域、坡度等级和县市区的分布特征,为南四湖流域不同风险区制定管理方案和控制对策提供科学依据。[方法]以数字高程模型(digital elevation model,DEM)为基础数据,运用ArcGIS软件,提取南四湖流域的DEM,制作坡度等级图,再运用水文分析功能,提取水系图、河流图、并划定子流域,结合2013年南四湖流域土地利用图,通过运用输出风险模型分析不同的土地利用类型和坡度下氮(N),磷(P)污染的空间变化。[结果]氮素的平均风险概率达到51.67%,磷素的平均风险概率达到9.14%,南四湖流域非点源污染输出风险湖东小于湖西;随坡度增大,高风险区面积减小,低风险区面积增加;就不同县市区而言,济宁市中区的N风险较小之外,其余县市区N风险均较大,P风险较小。[结论]N是流域最主要的非点源污染物,非点源污染输出风险大小与土地覆盖和坡度有密切关系。     

Yields of Green Grams and Pigeonpeas under Smallholder Conditions in Machakos County,Kenya

Green grams and pigeonpeas have multiple benefits to the rural poor as food security, fodder for livestock and fuel for small-scale farmers, despite low smallholder yields in Kenya. However, little is known about the factors between different farmers that influence the yields of green grams and pigeonpeas. The objectives of this study therefore were to describe and compare how the groups of farmers in agro-ecological zones (AEZs) LM 4 and LM 5 differ by their yields of green grams and pigeonpeas and to estimate the parameters of the variables which explain the yields. Data collection was through a well-structured questionnaire, administered to 364 respondents, selected through a multi-stage sampling technique. Each AEZ had an equal sample size (182 respondents). One-way analysis of variance (ANOVA) and multiple linear regression were used during data analysis. The ANOVA results showed that the mean of the green gram yields in AEZs LM 4 and LM 5 was 19.90 and 173.67 kg ha^?1 while the mean of the pigeonpea yields was 109.26 and 34.01 kg ha^?1, respectively. The multiple linear regression model results showed that the green gram yields were positively related to the use of improved seed (p?=?0.001), cultivated farm sizes (p?=?0.011), green gram crop intensity (p?=?0.005), oxcart (p?=?0.003) and agro-ecological zone (p?=?0.000). The farmer differences in the use of improved seed were found to be significantly and positively related to the yields of pigeonpeas (p?=?0.057), while the sizes of the cultivated farms (p?=?0.057) and the agro-ecological zones (p?=?0.000) showed inverse relationships (IRs). Based on the given research evidence, it was therefore concluded that the groups of farmers in AEZs LM 4 and LM 5 have different yields of green grams and pigeonpeas and there are factor gaps in productivity.