人工湿地去除畜禽养殖废水中磺胺类抗生素抗性基因研究

采用垂直潜流人工湿地研究了畜禽养殖废水中磺胺类抗生素抗性基因(ARGs)在人工湿地中的去除及累积情况.结果表明,畜禽养殖废水中的3种磺胺类ARGs(sul Ⅰ,sul Ⅱ及sul Ⅲ)的平均绝对含量分别为1.15×1010、7.51×1010及7.51×107 copies/L.通过湿地系统处理后sul Ⅰ、sul Ⅱ及sul Ⅲ的平均去除率分别为89％、88％及84％.在系统运行末期,湿地表层土壤和底层土壤中sul Ⅰ、sul Ⅱ及sul Ⅲ的绝对拷贝数和相对表达量均有明显的升高.结果表明,人工湿地系统可有效降低畜禽养殖废水中ARGs含量.     

Impact of Grazing Intensity during Drought in an Arizona Grassland

Abstract:  The ecological benefits of changing cattle grazing practices in the western United States remain controversial, due in part to a lack of experimentation. In 1997 we initiated an experimental study of two rangeland alternatives, cattle removal and high-impact grazing, and compared grassland community responses with those with more conventional, moderate grazing practices. The study was conducted in a high-elevation, semiarid grassland near Flagstaff, Arizona (U.S.A.). We conducted annual plant surveys of modified Whittaker plots for 8 years and examined plant composition shifts among treatments and years. High-impact grazing had strong directional effects that led to a decline in perennial forb cover and an increase in annual plants, particularly the exotic cheatgrass ( Bromus tectorum L.). A twofold increase in plant cover by exotic species followed a severe drought in the sixth year of the study, and this increase was greatest in the high-impact grazing plots, where native cover declined by one-half. Cattle removal resulted in little increase in native plant cover and reduced plant species richness relative to the moderate grazing control. Our results suggest that some intermediate level of cattle grazing may maintain greater levels of native plant diversity than the alternatives of cattle removal or high-density, short-duration grazing practices. Furthermore, episodic drought interacts with cattle grazing, leading to infrequent, but biologically important shifts in plant communities. Our results demonstrate the importance of climatic variation in determining ecological effects of grazing practices, and we recommend improving conservation efforts in arid rangelands by developing management plans that anticipate this variation.     

矿化垃圾生物反应床处理畜禽废水的试验研究

矿化垃圾具有较大的吸附比表面积 ,较强的阳离子交换容量 (6 7.9meq/ 10 0 g) ,无二次污染 ,是很好的污水处理生物介质。借助于矿化垃圾柱物理模型试验装置 ,在实验室进行了历时 6个月的矿化垃圾反应床处理畜禽污水试验。结果表明 ,系统出水有较大改善 ,出水溶解氧有较大提高 ,pH值呈中性。该处理系统对畜禽污水中色度、SS、CODCr、BOD5、NH3 N和总磷的平均去除率分别为 6 4.7%、5 4.2 9%、75 .33 %、88.71%、94.5 5 %和 99.83 % ;处理出水中CODCr、BOD5、NH4 N和总磷的平均浓度分别为 185 .6 1mg/L、14.94mg/L、2 6 .79mg/L和 0 .0 79mg/L ;总氮的平均去除率仅为 2 1.2 9%。反应器运行 6个月以来 ,运转良好 ,未发生阻塞现象     

我国集约化畜禽养殖场污染治理障碍分析及对策

随着我国集约化畜禽养殖场的快速发展，行业污染危害日益严重，对自然环境和居民健康威胁很大。由于技术经济原因，只有综合利用、农牧一体的方法才能根本解决养殖场污染问题，但这种方式在我国存在着诸多推广障碍：环境标准和监管体系有缺陷、资金和技术门槛较高、副产品没有获得应有的市场回报等。建议采取以下措施促进综合利用：提高养殖场的排污标准和排污费征收标准，按照工业污染治理的办法进行养殖场环境监管，对这类污染在重点地区开展专项整治，从税收、土地价格、贷款等方面扶持综合利用。     

主基因研究与畜禽遗传资源开发

论述了畜禽主基因的概念、利用价值及研究状况，指出我国畜禽遗传资源的开发，实质上就是要发掘利用特异性状的主基因，并就如何开发利用主基因进行了探讨。     

Absorption of phosphorus from wastewater by aged refuse excavated from municipal solid waste landfill

Municipal solid waste(refuse) landfill stabilizes as the refuse degrades. After years of biodegradation, the refuse in the landfill ecomes stabilized and aged, which may vary with the local climate, humidity, and composition of refuse placed. In this work, it is found hat the refuse with an age of over 8 years at Shanghai Refuse Landfill has been significantly stabilized and sufficiently aged and is thus uitable for excavation. The 8-year old aged refuse is mechanically screened, and the fine fractions of refuse(aged refuse) with a diameter ess than 2 cm are then used as a biological absorbent for removal of both inorganic and organic phosphorus in livestock wastewater and repared aqueous solution. It is proved that the aged refuse is very effective for the quantitative removal of both types of phosphorus. The bsorption mechanism is proposed. It is considered that phosphorus is firstly absorbed onto the surface of the aged refuse and then used s a substrate for the growth of microorganisms which ultimately leave the aged refuse as sludge.     

我国规模化畜禽养殖业存在的环境问题与防治对策

近年来，由于我国畜禽养殖业的养殖规模、养殖方式和分布区域发生了巨大的变化，它所带来的环境污染问题总体呈现出总量增加、程度加剧和范围扩大的趋势，归纳了我国规模化畜禽养殖业环境污染的特点，从生产、技术、政策和管理上分析了影响我国畜禽养殖业环境污染的主要因素，并提出了污染防治的对策建议，即借鉴发达国家畜禽养殖业的环境管理经验，以减量化、资源化、无害化及实用、廉价为原则，合理规划、防治结合，努力探索一条具有中国特色的规模化畜禽养殖污染防治道路。     

华中地区畜牧业温室气体排放特征分析与预测

采用IPCC推荐的温室气体清单计算方法,从温室气体排放总量、排放强度等方面分析了华中地区畜牧业温室气体排放现状;根据不同牲畜饲养数量,采用Logisticgrowth model、Gompertzcurve model等非线性时间序列模型模拟2030年华中地区牲畜数量,并计算畜牧业温室气体排放量.结果显示,2015年华中地区温室气体排放为6289.09万t CO₂-eq,单位GDP温室气体排放量为1.13万t CO₂-eq/亿元,单位肉类产量排放强度为3.73t CO₂-eq/t;2030年华中地区畜牧业温室气体排放总量约为4990.06（温室气体排放预测1）~5932.74万tCO₂-eq（温室气体排放预测2）.应当进一步优化畜牧业饲养技术及条件来提高产业温室气体排放效率,科学合理的规划不同牲畜的饲养规模,优化牲畜饲养结构来降低畜牧业温室气体排放量.     

基于二污普数据果菜茶畜禽粪污氮承载评估

为评估我国各省份果菜茶种植对当地畜禽粪污承载消纳能力,基于各省份果菜茶产量数据与第二次全国污染源普查结果分别核算了畜禽粪肥氮需求量和供给量,以粪肥替代化肥比率为0.4和0.5两种情景评估了各省份果菜茶种植粪肥氮承载消纳情况.结果表明:①全国果菜茶种植氮素平均需求量为358.7 kg/hm2,畜禽养殖业粪肥氮素产生量为463.3×104 t,供给量为277.97×104 t.果菜茶单位种植面积粪肥氮素供给量全国平均值为126.37 kg/hm2.②粪肥替代化肥比率为0.4时,全国果菜茶单位种植面积粪肥氮养分需求量为143.5 kg/hm2,各省份粪肥氮养分承载压力系数在0.21~2.99之间,平均值为0.78.③粪肥替代化肥比率为0.5时,全国果菜茶单位种植面积粪肥氮养分需求量为179 kg/hm2,各省份粪肥氮养分承载压力系数在0.17~2.39之间,平均值为0.63.研究显示,粪肥替代化肥比率在0.4和0.5条件下,全国大部分省份畜禽粪肥氮养分提供量未超过本区域果菜茶种植的肥料所需.各省份畜禽养殖业可提供的粪污全部用于区域内果菜茶作物施肥,全国有22个省份粪肥替代化肥的比率在0.4之内.      

禽畜粪便减量化处理技术初探

随着中国养殖业的迅速发展,禽畜粪便的排放数量逐年增加。据统计,禽畜粪尿排放量每头牛为55kg/d~65 kg/d,每头猪为3.5 kg/d~11.0 kg/d,每只鸡为0.10 kg/d~0.15 kg/d,每只羊为2.66 kg/d。大量的禽畜粪便不经处理而排入环境,将会对地表水、地下水、土壤和空气造成严重的污染,并危及禽畜本身及人体健康。因此,实现禽畜粪便的减量化、无害化及资源化,防止和消除养殖场粪便的污染及其利用问题的研究,对于生态环境的保护、实施可持续发展战略都具有十分重要的意义。本试验利用日本JST赠送的生态厕所反应装置为试验设备,分别以木屑和木屑与秸秆混合物为微生物载体,对牛粪便进行减量化处理技术研究。旨在为研究中国农业的玉米作物秸秆是否可以替代木屑作为反应过程中的调理剂,达到对禽畜养殖业粪便良好的减量化处理效果,减轻对环境的污染,同时也为中国大量的农作物秸秆寻找另一条资源化利用途径。