The MANAGE database: nutrient load and site characteristic updates and runoff concentration data

The "Measured Annual Nutrient loads from AGricultural Environments" (MANAGE) database was developed to be a readily accessible, easily queried database of site characteristic and field-scale nutrient export data. The original version of MANAGE, which drew heavily from an early 1980s compilation of nutrient export data, created an electronic database with nutrient load data and corresponding site characteristics from 40 studies on agricultural (cultivated and pasture/range) land uses. In the current update, N and P load data from 15 additional studies of agricultural runoff were included along with N and P concentration data for all 55 studies. The database now contains 1677 watershed years of data for various agricultural land uses (703 for pasture/rangeland; 333 for corn; 291 for various crop rotations; 177 for wheat/oats; and 4-33 yr for barley, citrus, vegetables, sorghum, soybeans, cotton, fallow, and peanuts). Across all land uses, annual runoff loads averaged 14.2 kg ha(-1) for total N and 2.2 kg ha(-1) for total P. On average, these losses represented 10 to 25% of applied fertilizer N and 4 to 9% of applied fertilizer P. Although such statistics produce interesting generalities across a wide range of land use, management, and climatic conditions, regional crop-specific analyses should be conducted to guide regulatory and programmatic decisions. With this update, MANAGE contains data from a vast majority of published peer-reviewed N and P export studies on homogeneous agricultural land uses in the USA under natural rainfall-runoff conditions and thus provides necessary data for modeling and decision-making related to agricultural runoff. The current version can be downloaded at http://www.ars.usda.gov/spa/manage-nutrient.     

城市生活垃圾生命周期管理

生命周期评价是一种全面的环境管理工具,具有潜在的发展前景。０它通过对产品,产品系统,工艺活动整个生命周期的环境影响环境改善的机会进行评价。根据国际环境毒理与化学学会１９９３年和ＩＳＯ１４０００环境管理体系中关于生命周期评价的技术框架,本文应生命周期评价在城市生产垃圾管理系统中的作用及管理系统的清单分析,影响评价和改善评价进行研究。     

pH、温度和水土比对酸性土壤溶液中铝离子形态分布的影响

溶液中Al3 、Al-F和有机络合态铝（Al-OM的浓度随pH降低而增加,Al3 在总单核铝中所占比例随pH的降低而增加,而Al-F络合物呈相反的变化趋势.土壤中铝的溶解度与土壤中铝氧化物的结晶形态有关,处于较高纬度地区的土壤,由于铝氧化物的结晶形态较差,在相同pH下,其铝的溶解度较大.土壤溶液中有机络合态铝的浓度随温度升高而增加,在pH不变的情况下,土壤中无机铝的溶解量随温度降低而增加.随水土比增加,土壤溶液中Al3 、Al-F络合物和Al-OM浓度减小,但按每kg土计算的铝溶解量随水土比的增加而增加.     

肥效调节型肥料的特性

对肥效调节型肥料的概念、类型、溶解特性及肥效性做了详释．并指出随着我国经济高速发展、公民环保意识增强,肥效调节型肥料将在我国未来肥料市场占有一席之地     

土壤与酸的反应时间对土壤酸度及土壤溶液中铝离子形态分布的影响

用两种土壤研究土壤与酸的反应时间对土壤酸度及土壤溶液中铝离子形态分布的影响。结果表明,土壤溶液pH随反应时间增加而增加,安徽红壤pH的增幅大于江西红壤。在pH3.0的HNO3溶液中,土壤溶液中的总铝及Al3 均随反应时间增加而减少,而在pH3．5的HNO3溶液中,土壤溶液中总铝及Al－F络合物先随反应时间的增加而减小．然后又有所增加。     

阳离子表面活性剂十六烷基三甲基溴化铵对酞酸酯类化合物增溶性研究

用阳离子表面活性剂十六烷基三甲基溴化铵对六种酞酸酯类化合物(五种脂肪链酞酸酯和一种苯基酞酸酯)进行了增溶性实验．结果表明,在表观浓度(Ｃｓ)小于临界胶速浓度(ＣＭＣ)时,十六烷基三甲基溴化铵对四种酞酸酯(ＤＭＰ和ＤＰｈＰ除外)有一定程度的增溶作用;当Ｃｓ大于ＣＭＣ时,对六种化合物的增溶性显著增强．其增溶性(Ｓｔ/Ｓｗ)随Ｃｓ增大而线性递增:当Ｃｓ＜ＣＭＣ时,Ｓｔ/Ｓｗ＝ａ＋Ｋｍｎ·Ｃｓ,ｒ＞０．９０,ｎ＝５;当Ｃｓ＞ＣＭＣ时,Ｓｔ/Ｓｗ＝ａ＋Ｋｍｃ·Ｃｓ,ｒ＞０．９９,ｎ＝５． 各化合物增溶系数随各自固有水溶性(Ｓｗ)减小而增大(苯基酞酸酯有所反常),ｌｇＫｍｎ和ｌｇＫｍｃ与各自ｌｇｌ/Ｓｗ具有良好的线性正相关性．本文进一步对增溶机理进行了分析解释．     

垃圾堆肥场堆肥废气环境影响评价分析

垃圾堆肥场的建设将改变目前垃圾任意堆放的局面 ,堆肥产品可用于林业使垃圾得到无害化处理 ,并变废为宝。尽管如此在垃圾堆肥过程中还将释放出有害气体和垃圾渗透液等影响环境质量。针对堆肥所产生的大气污染物进行源强确定、扩散计算 ,分析其影响范围并推算卫生防护距离。     

Mussel isotope signature as indicator of nutrient pollution in a freshwater eutrophic lake: species, spatial, and seasonal variability

Stable nitrogen isotope ratios of five mussel species from littoral and pelagic areas were investigated with different trophic states in the eutrophic Lake Taihu, the third largest lake in China. Interpopulation variability for these mussels was relatively small in foot tissues because of the slow turnover time. Seasonal and spatial variations among the δ ¹⁵N values of mussels might be due in part to the natural variation in δ ¹⁵N values of potential food sources and the variation in the amount of human pollutions discharged into various locations of the lake. Although the increase of mussel δ ¹⁵N values was accompanied by the increase of nutrient concentrations in most situations in this study, statistically significant correlations were only 22% of the total correlations in this survey, which might be attributed to the different time-scale variations in nutrient concentrations and isotope signatures and the unknown details of the trophic pathways and metabolism for incorporation of these nutrients.