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。     

Nitrogen turnover on organic and conventional mixed farms

Separate focus on crop fertilization or feeding practices inadequately describes nitrogen (N) loss from mixed dairy farms because of (1) interaction between animal and crop production and between the production system and the manager, and (2) uncertainties of herd N production and crop N utilization. Therefore a systems approach was used to study N turnover and N efficiency on 16 conventional and 14 organic private Danish farms with mixed animal (dairy) and crop production. There were significant differences in N surplus at the farm level (242 kg. N/ha. vs. 124 kg. N/ha. on conventional and organic dairy farms respectively) with a correlation between stocking rate and N surplus. N efficiency was calculated as the output of N in animal products divided by the net N import in fodder, manure and fertilizer. N turnover in herd and individual crops calculated on selected farms showed differences in organic and conventional crop N utilization. This is explained via a discussion of the rationality behind the current way of planning the optimum fertilizer application in conventional agriculture. The concept of marginal N efficiency is insufficient for correcting problems of N loss from dairy farms. Substantial reductions in N loss from conventional mixed dairy farms is probably unlikely without lower production intensity. The concept of mean farm unit N efficiency might be a way to describe the relation between production and N loss to facilitate regulation. This concept is linked to differing goals of agricultural development—i.e. intensification and separation vs. extensification and integration. It is discussed how studies in private farms—using organic farms as selected critical cases—can demonstrate possibilities for balancing production and environmental concern.     

我国热带地区胶-茶-鸡农林复合系统物质循环研究

以海南省文昌市典型的胶-茶-鸡农林复合模式为研究对象 ,以单作胶园、胶茶间作园为对照 ,采用定量研究与定性分析相结合的方法 ,研究其物质循环规律。结果表明 ,胶-茶-鸡农林复合系统的氮、磷输入、输出量最大 ,系统外物质投入率比另两系统明显减少 ,系统内养分循环量增加 ,因此 ,该系统具有较合理的物质循环结构。     

陕南富硒茶的分布与开发利用

对陕南主要茶区进行了茶叶和茶园土壤的系统采样和分析,并对富硒茶的硒量作了初步探讨.建议用富硒茶作为低硒区人体硒的补充来源.讨论了富硒保健茶的含硒标准.提出了陕南富硒保健茶的分布范围和含硒水平.     

Study of ciprofloxacin removal by biochar obtained from used tea leaves

In this study,used tea leaves(UTLs) were pyrolyzed to obtain used tea-leaf biochar(UTC),and then the UTC was used as an adsorbent to remove ciprofloxacin(CIP) from aqueous solutions.Batch experiments were conducted to investigate the CIP adsorption performance and mechanism.The results showed that the CIP-adsorbing ability first increased and then declined as the UTC pyrolysis temperature increased.The UTC obtained at 450°C presented excellent CIP-absorbing ability at p H 6 and 40°C.The maximum monolayer adsorption capacity was 238.10 mg/g based on the Langmuir isotherm model.The pseudo-second-order kinetic equation agreed well with the CIP adsorption process,which was controlled by both external boundary layer diffusion and intra-particle diffusion.The characterization analysis revealed that the \OH groups,C_C bonds of aromatic rings,C\H groups in aromatic rings and phenolic C\O bonds play vital roles in the CIP adsorption process,and that the N\C,N\O,O\C_O and C\OH groups of UTC were consumed in large quantities.π–π interactions,hydrogen bonding and electrostatic attraction are inferred as the main adsorption mechanisms.The present work provides not only a feasible and promising approach for UTLs utilization but also a potential adsorbent material for removing high concentrations of CIP from aqueous solutions.     

黄山茶叶品质与产地地质背景关系探讨

本文通过对黄山茶叶的实地调查,从地学角度分析了黄山茶叶的地质背景对土壤中元素组合、土壤类型的影响,探讨了茶叶主要品质与产地地质背景的关系,分析了茶叶优异的品质与地质背景条件的相关性。确定出黄山毛峰生长的土壤是在特定的青白口纪邓家组变石英砂岩、变粉砂岩、板岩风化而成的粗骨土,太平猴魁是在特定志留纪康山组长石石英砂岩、粉砂岩、泥岩风化而成红壤土、粗骨土,这些土壤为茶树生长提供了大量的营养物质,特别是有益的微量元素对提高茶叶品质起到了重要作用。     

长沙“百里茶廊”茶园土壤重金属含量及环境质量特征

采用野外调查采样和室内分析方法测定了长沙"百里茶廊"茶叶基地土壤重金属含量,研究了其分布特征及变化规律,并用污染指数方法评价了其土壤环境质量.结果表明,土壤全铅、全汞、全镉、全铬、全砷和全镍含量值基本在土壤背景值范围内,平均含量值分别为42.7、0.068、0.074、92.2、12.4和19.5 mg/kg.均低于无公害茶叶产地环境条件标准(NY 5020-2001)所要求的最低值.根据国家<土壤环境质量标准>,长沙"百里茶廊"茶叶基地的土壤环境质量全部符合国家二级标准.且汞、镉、镍元素的含量达到国家一级标准.除湘丰茶场土壤铬的单项污染指数为0.837,处于警戒级别土壤质量尚清洁外,其它5种重金属的单项污染指数均小于0.7,处于安全级别土壤清洁无污染.6个茶叶基地的综合污染指数均小于0.7.表明长沙"百里茶廊"茶叶基地的土壤环境质量总体达到安全级别土壤清洁无污染.适合无公害茶叶基地的建设.     

Estimating population dynamics without population data

We develop a biologically correct cost system for production systems facing invasive pests that allows the estimation of population dynamics without a priori knowledge of their true values. We apply that model to a data set for olive producers in Crete and derive from it predictions about the underlying population dynamics. Those dynamics are compared to information on population dynamics obtained from pest sampling with extremely favorable results.     

不同pH的柠檬酸对茶园土壤溶出液中氟组分变化的影响

通过连续流动搅拌法,研究了不同pH的柠檬酸对茶园土壤溶出液中氟组分变化的影响.结果表明,土壤溶出液的pH随溶出时间的延长而逐渐减小.土壤溶出液中的游离态氟和总氟的浓度随时间的延长和柠檬酸pH的升高而逐渐减小,且呈现初始(0—6h)溶出浓度较高,而后(6—10h)逐渐减缓的趋势.土壤氟的溶出过程用一级动力学方程、Elovich方程、扩散方程和双常数方程均有较好的拟合,决定系数(R2)均大于0.90.低pH(pH3.5)条件下,F主要以H-F形态存在,随着pH的升高(pH4.0—5.0),H-F形态的氟减小,Al-F络合态的氟增多,且随时间延长,溶出浓度均降低.反应开始的前1h,Al-F络合物主要以AlF3为主,占氟溶出总量的90%以上;至7h时,AlF+2的溶出量逐渐增大,并逐渐超过AlF3.低pH的柠檬酸促进土壤游离态氟和总氟的溶出,有利于络合态氟的形成,但对Al-F络合物的形态转化没有显著影响.     

三叶虫茶茶多酚提取工艺研究

研究萃取-沉淀法从虫茶中提取分离茶多酚的影响因素.采用单因素循环法考虑各影响因素,得出三叶虫茶茶多酚的最优提取工艺.用回流法提取茶多酚,并用单因素循环法分别考察提取剂、沉淀剂、转溶酸、萃取次数对茶多酚提取率的影响,用紫外-可见分光光度法对提取液进行检测.用萃取-沉淀法从虫茶中提取分离茶多酚,以80%丙酮作提取剂,Zn Cl2作沉淀剂,盐酸转溶的效果较为理想.结论表明,萃取-沉淀法提取分离虫茶中茶多酚,所需要的有机溶剂少,能耗低,纯度高,具有可行性.图4,表5,参14.