有机固体废弃物在持续农业中的资源化利用

有机固体废弃物产生量巨大且成分复杂,其对环境的污染已越来越多地引起人们的关注.它含有大量营养成分和有机质,在农业生产上除可以满足作物生长对养分的需要外,其丰富的有机质含量还可以改善土壤的物理化学性状,培肥土壤,有利于农业的可持续发展.有机固体废弃物的农业资源化处理利用是最积极有效的措施之一.     

广东省节水与旱作农业基本情况调查报告

全省节水与旱作农业基本情况调查结果表明：干旱缺水是影响旱坡地作物产量提高的主要因子.近年来.我省采用节水灌溉技术、节水耕作技术、优化种植结构等措施,提高了水资源的利用率.今后,在旱坡地上开发节水高效农业大有潜力.     

Fish consumption reduces transfer of BDE47 from dam to murine offspring

Fish and seafood are important contributions to a healthy diet, but also contain persistent organic pollutants (POPs) like polybrominated diphenylethers (PBDEs) and polychlorinated biphenyls (PCBs). Discrepancies have been found between intake and accumulated levels of POPs, where fish consumers have had similar levels of POPs to the general population. Similarly fish oil consumption has been found to reduce accumulation of POPs. This study examined the accumulation of BDE47 or PCB153 in mice fed diets with different nutritional composition, using female mice with pre-weanling pups exposed through gestation and lactation. A fish-based diet was compared to a standard casein-based rodent diet. All diets had low background levels of environmental contaminants and were spiked with BDE47 or PCB153 to levels representing a realistic (∼0.004 μmol kgbw⁻¹ d) or a high dietary exposure (∼1.3 μmol kgbw⁻¹ d). Accumulation of BDE47 or PCB153 in offspring tissues after 18 d lactation reflected the maternal exposure levels. However, the pups of dams fed a fish-based diet had consistently lower BDE47 accumulation in liver, fat and stomach than pups from casein-fed dams. Similarly the pups of dams fed a high dose of PCB153 in a fish diet also accumulated less PCB153 than pups of the dams fed a casein diet, although not significant. In conclusion, the fish based diets seemed to reduce transfer of BDE47 and PCB153 from dams to pups. The study highlights that in-depth knowledge about nutritional impact on toxicokinetics is of great interest to vulnerable consumers.     

中国农业温室气体排放:现状及挑战

该文从农业生产过程和化肥、能源等投入方面计算了中国农业温室气体排放.2009年,中国农业总计排放温室气体158 557.3万t CO2当量,比1980年增长52.03％,年均增长1.46％.其中,CH4占总排放的25％,N2O占总排放的52％,CO2占总排放的23％.按来源分析,在2009年排放的温室气体中,水稻种植排放14 264.45万t,占9％;畜牧生产排放42 709.94万t,占26.94％;土壤排放47 457.81万t,占29.93％;化肥、能源、农药、农膜等投入引起的排放54 125.11万t,占34.14％.2009年农业GDP排放的温室气体为2.98 kg/元,粮食排放的温室气体为1.5 kg/kg.在2008年,牛肉排放的温室气体为28.54 kg/kg,羊肉为15.5 kg/kg,猪肉为1.49kg/kg,禽肉为0.54 kg/kg,牛奶为1.04 kg/kg,禽蛋为0.83 kg/kg.由于技术进步和生产效率提高,单位粮食、肉类和牛奶排放的温室气体都有较大幅度降低.对于种植单季粮食的土地,CO2交易价格为80元/t将使23.27％的耕地退出粮食生产;当CO2交易价格为100元/t时,这一比例高达63.31％.对于种植双季粮食的土地,CO2交易价格为130- 140元/t时,将有50％的耕地退出粮食生产.由于中国粮食生产利润率过低,CO2较低的价格使严重影响粮食生产面积和产量.     

华北平原冬小麦-夏玉米种植模式碳足迹研究

农业碳足迹理论可以系统评价农业生产过程中人为因素引起的碳排放,是构建低碳农业的理论基础,对实现低碳农业其有重要的指导意义.为探明农业生产中的碳足迹,本文基于河北吴桥县农户生产调查数据,利用农业碳足迹理论及研究方法,评价了华北平原冬小麦-夏玉米两熟种植模式的碳足迹.结果表明:冬小麦-夏玉米种植模式碳足迹的大小为1 737.37±337.02 kgCe/hm2·a,生产1 kg粮食的碳成本是0.12±0.03 kgCe,其中冬小麦的碳足迹是1 101.31±251.91 kgCe/hm2·a,小麦的碳成本是0.16±0.04kgCe/kg,夏玉米的碳足迹是636.06±163.90 kgCe/hm2·a,玉米的碳成本是0.08±0.02 kgCe/kg.冬小麦-夏玉米种植模式碳足迹的组成中,化肥占总量的61.76％,电能占25.03％,柴油占7.44％,种子占4.75％,农药占1.02％.同时,发现N肥的施用量和电能消耗量均与碳足迹有正相关性,种植规模与碳成本有负相关性.因此,构建节肥、节水及规模化的低碳种植模式是实现华北平原农业节能减排的重要途径.     

生物膜水解-好氧循环系统处理活性艳蓝RB-19的微生物群落动态变化

为了研究生物膜水解-好氧循环系统处理蒽醌类染料活性艳蓝RB-19效果及其中微生物群落动态变化,利用基于16S rDNA的PCR-DGGE技术获得了微生物群落的DNA特征指纹图谱。结果表明,该系统能有效地降解活性艳蓝RB-19模拟废水,在RB-19浓度≤400 mg/L时,RB-19去除率维持在82%～96%之间,COD去除率维持在95%左右,但当RB-19浓度提高到500 mg/L时,RB-19去除率降低到58%,COD去除率降低到85%。DGGE分析表明,生物膜上的微生物群落结构随着RB-19浓度递增有显著变化,好氧、水解反应器内的细菌Shannon指数分别从1.32和1.20降低到1.11和1.19。UPGMA聚类分析和NMDS散点分析表明,水解、好氧反应器内的微生物并没有因为同处一个系统内而使得其菌群落结构产生明显的趋同倾向。系统内的多种优势菌群为兼性细菌,克隆测序的结果发现,在水解反应器存在一类具有很强还原能力的古细菌——Methanobacterium sp.MB4。     

Desalinated versus recycled water: public perceptions and profiles of the accepters

Many countries' water resources are limited in both quantity and quality. While engineering solutions can now safely produce recycled and desalinated water from non-potable sources at a relatively low cost, the general public is sceptical about adopting these alternative water sources. Social scientists, policy makers and technical experts need to better understand what is causing this lack of acceptance by the general population and how acceptance levels for recycled and desalinated water can be increased. This study is the first to conduct a comparative analysis of knowledge, perceptions, and acceptability, and determine segments of residents who are more open-minded than the general population toward the use of recycled and desalinated water. The Australian population once perceived desalinated water as environmentally unfriendly, and recycled water as a public health hazard. The general level of knowledge about these two concepts as potential water sources has historically been low. After nearly five years of serious drought, accompanied by severe water restrictions across most of the country, and subsequent media attention on solutions to water scarcity, Australians now show more acceptance of desalinated water for close-to-body uses, and less resistance to recycled water for garden watering and cleaning uses. The types of people likely to be strong accepters of the two alternative water sources are distinctly different groups, and can be reached through different media mixes. This finding has significant implications for policy makers and water practitioners.     

高校人工湿地系统的规划设计——以福建工程学院新校区为例

人工湿地处理技术具有投资低、出水水质好、耗能低、抗冲击力强、操作简单和运行费用低等优点。本文阐述了人工湿地系统应用于高校生活污水回收利用的意义,以福建工程学院新校区的北校区为例,利用前期在福州大学模拟人工湿地系统处理生活污水的实验数据,规划设计人工湿地系统,计算确定相关设施的面积和尺寸,并对人工湿地系统进行平面布置,绘制出系统流程的剖面图。     

日本应对面源污染的法律措施

自1992年农林水产省首次提出“环境保全型农业”的概念以来,日本政府逐渐重视以农业污染为主的面源污染。此后,政府根据面源污染在各个时期的变化情况,把农业生产污染、禽畜养殖业污染、固体废物污染、高速公路和城市生活污染等方面的各种政策、目标和经济措施予以法制化,陆续出台了一系列有利于防治面源污染的法律、法规。这些法规虽然不是防治面源污染的单行性法规,但其内容具有配套性、系统性、可操作性的特点,惩戒措施也具有针对性和层次性的特点,而且经济措施与法律责任并举,客观上对防治面源污染起到了重要作用。借鉴日本的立法经验,我国防治面源污染立法应该进一步完善法律法规,明确管理部门的职责,强化法律责任,通过多种手段引导公民自觉防治面源污染.     

Evaluation of Poly(ethylene-terephthalate) Products of Chemical Recycling by Differential Scanning Calorimetry

Poly (ethylene-terephthalate), (PET) bottles waste was chemically recycled by glycolysis and hydrolysis. The depolymerization processes were carried out in different time intervals from 5 to 360 min, in two different molar ratios of PET/EG, 1:5 and 1:18 and at different temperatures. The PET glycolysis leads to formation of bis(2-hydroxy-ethyl)terephthalate (BHET) monomer and PET oligomers with hydroxyl and carboxyl end groups while PET hydrolysis is followed by formation of monomers terephthalic acid (TPA) and ethylene glycol (EG). Fractions of monomers and oligomers were further characterized by FTIR spectroscopy and by differential scanning calorimetry (DSC). The results show that DSC is successful method to describe the different structures of oligomers formed during chemical recycling of PET.