S195柴油机燃用菜籽油的试验

以菜籽油为燃料，对S195柴油机燃油性能进行了研究，结果表明，在发动机结构不经改动的情况下，燃用菜籽油或菜籽油与柴油的混合油是可行的，发动机燃用菜籽油或混合油时，其排放污染下降，但耗油率均有所上或，且燃烧室和喷油嘴积炭较多，发动机燃用50％菜籽油与50％轻柴油的混合油，且供油提前角为20度CA时燃烧性能较好。     

在小区内排放废水 谨防构成污染环境罪

<正>编辑同志:我们是一小区的业主。居住在一楼的钟某从两年前起,在既无环保审批手续,也无污染防治设施的情况下,即利用室内从事非法电镀加工,产生的污水则直接排放到小区的水沟、渗坑、过道等公共场所。经环保部门对电镀废水现场采样鉴定,样品中含六价铬、铅、锌等多种有毒化学物质。其中六价铬8.49×102mg/L,大大超过《电镀污染物排放标     

农业污染源的普查技术

2008年初国务院决定开展第1次全国污染源普查,此次普查涉及面广,全国31个省（自治区、直辖市）所有排放污染物的工业污染源、农业污染源、生活污染源单位和集中式污染治理设施均作为此次污染源普查的对象,目的是全面了解各类污染源的数量、行业和地区分布、污染物排放情况和污染治理情况等,从而全面掌握污染源的样本总数、建立新的环境统计平台。普查的标准时点为2007年12月31日,时期资料是2007年度。本文将介绍种植业、畜禽养殖业和水产养殖业污染源的普查技术。     

科学家称农业源温室气体排放是"生存排放"

据《中国农业工程学报》2008年10月报道,农业源温室气体排放占我国温室气体排放总量的17％,但来自农业源的排放是农业生产的自然’过程,农业源的温室气体排放属于“生存排放”。研究表明,通过改善反刍动物营养、推广稻田间歇灌溉、建设沼气、推行缓释肥、长效肥料可以减缓农业源温室气体排放,但急需进行技术和经济性评估。     

重庆市城市生活垃圾填埋甲烷排放量估算

采用中推荐的基于动力学模型的一阶衰减(FOD)方法估算了重庆市直辖十年以来因城市生活垃圾(MSW)产生的CH4排放量.结果表明,1997年至2007年间重庆城市生活垃圾CH4排放量总体呈递增趋势.对甲烷产生率k值及生活垃圾构成中可降解有机碳比例对CH4排放量估算结果的影响分析表明,可降解有机碳较对估算结果的影响更大,两者不确定性的交互作用对估算量带来的不确定性约为33%.     

垃圾填埋场覆土层植物根围甲烷氧化活性研究

采用滚管计数法和气相色谱法,研究了植物因素对垃圾填埋场封场覆土层中甲烷氧化菌的数量及其甲烷氧化活性的影响。结果表明:垃圾填埋场不同植物根围土壤中甲烷氧化茵的数量为1×10~7～1×10~8cfu·g~(-1),甲烷氧化速率为1×10~(-7)～1×10~(-8)mol·h~(-1)·g~(-1);封场时间越短,覆土层中甲烷氧化菌的数量及其甲烷氧化活性越高;甲烷氧化茵数量与甲烷氧化活性之间存在一定的正相关性,但甲烷氧化茵的数量并不是影响甲烷氧化活性的唯一因素。随着植物覆被土壤中的甲烷氧化菌的数量增多,不同种类植物根围的甲烷氧化活性差异明显,比裸露地高38%～45%。建议将小蓬草(Conyza canadensis)、稗(Echinochloa crusgalli)、佛甲草(Sedum lineare)等作为填埋场封场后的甲烷净化功能性先锋物种进行种植。     

Soil CO2 and N2O Emissions in Maize Growing Season Under Different Fertilizer Regimes in an Upland Red Soil Region of South China

Upland red soils have been identified as major CO2 and N2O sources induced by human activities such as fertilization. To monitor characteristics of soil surface CO2 and N2O fluxes in cropland ecosystems after continuous fertilizer applications over decades and to separate the respective contributions of root and heterotrophic respiration to the total soil CO2 and N2O fluxes, the measurements of soil surface CO2 and N2O fluxes throughout the maize growing season in 2009 were carried out based on a fertilization experiment （from 1990） through of the maize （Zea mays L.） growing season in red soil in southern China. Five fertilization treatments were chosen from the experiment for study： zero-fertilizer application （CK）, nitrogen-phosphorus- potassium （NPK） fertilizer application only, pig manure （M）, NPK plus pig manure （NPKM） and NPK with straw （NPKS）. Six chambers were installed in each plot. Three of them are in the inter-row soil （NR） and the others are in the soil within the row （R）. Each fertilizer treatment received the same amount of N （300 kg ha-1 yr-1）. Results showed that cumulative soil CO2 fluxes in NR or R were both following the order： NPKS〉M, NPKM〉NPK〉CK. The contributions of root respiration to soil CO2 fluxes was 40, 44, 50, 47 and 35% in CK, NPK, NPKM, M and NPKS treatments, respectively, with the mean value of 43%. Cumulative soil N2O fluxes in NR or R were both following the order： NPKS, NPKM〉M〉NPK〉CK, and soil N2O fluxes in R were 18, 20 and 30% higher than that in NR in NPKM, M and NPKS treatments, respectively, but with no difference between NR and R in NPK treatment. Furthermore, combine with soil temperature at -5 cm depth and soil moisWxe （0-20 cm） together could explain 55-70% and 42-59% of soil CO2 and N2O emissions with root interference and 62- 78% and 44-63% of that without root interference, respectively. In addition, soil CO2 and N2O flUXeS per unit yield in NPKM （0.55 and 0.10 kg C t^-1） and M （0.65 and 0.13 g N t^-1） treatments were lower than those in other treatments. Therefore, manure application could be a preferred fertilization strategy in red soils in South China.     

日光温室山墙及栽培基质热通量特征分析

试验采用PC-2R型热通量记录仪对酒泉肃州区非耕地日光温室的山墙及栽培基质热通量进行实时监测,并对温室山墙及栽培基质热通量变化特性进行了分析.结果表明:温室东西山墙单位面积吸热量平均值分别为1.41MJ/m2和1.67MJ/m2,单位面积墙体放热量平均值为0.34MJ/m2和0.63MJ/m2;天气状况只影响山墙热通量值的大小,对其热通量达到最大值的时刻无影响;白天栽培基质表层平均吸热量为0.59 MJ/m2,夜间栽培基质表层平均放热量为0.17 MJ/m2;随栽培基质深度的增加,热通量变化幅度逐渐降低,蓄热的时间依次延迟;15cm以下基质热通量全天均为负值,晴天与阴天吸放热差异不明显;晴天夜间山墙单位面积放热量高于基质,阴天则小于基质.     

Effect of Biogas Digested Liquid on OH4 and N2O Flux in Paddy Ecosystem

Biogas production generates digested slurry as a byproduct. It can be used as a fertilizer especially after its conversion into digested liquid. A pot based study was conducted in order to evaluate the effect of the application of digested liquid on CH4 and N2O flux, and plant biomass in paddy. Analysis revealed that digested liquid treated soils released more CH4 compared to ammonium sulphate and the control. Ammonium sulphate treated soil emitted the highest N20 whereas digested liquid application decreased its emission significantly. Further, the cumulative emission over 101 d of the experiment was found to be higher for CHa （16.9 to 29.9 g m^-2） compared to N20 （-49.3 to 18.9 mg m^-2） for all treatments. Digested liquid application had positive impact on plant variables such as panicle number and weight of panicles. This study suggests that digested liquid application significantly decrease N20 emission and increase CH4 emission possibly due to affecting the availability of organic C in the soil to microbial activity for methanogenesis. Another possibility for enhancing CH4 emission by following biogas digested liquid could be attributed to the increase in plant biomass.     

2015年冬季南黄海水文特征及海-气CO2通量分析

基于2015年冬季在南黄海海域现场观测获得的CTD和CO2等数据,分析了该海域海-气CO2通量,探讨了该海域冬季温、盐度和表层CO2分压(pCO2)等要素的分布特征及其影响因素.结果表明:冬季南黄海西侧海域受黄海沿岸流的影响,呈现低温、低盐的特征,南黄海中部受黄海暖流影响,呈高温高盐特征;南黄海靠近沿岸海域水体垂直混合强烈,温盐垂直分布较为均匀.南黄海海域表层pCO2平均值为(385.34±43.62) μatm.表层pCO2分布具有明显的区域差异,海区中部pCO2整体上大于近岸,因受长江冲淡水与黄海沿岸流的水平及垂直混合作用,长江口北部局部区域最高通量达27.81 mmol/(m2·d),但总体表现为大气碳汇,平均通量达(-2.47 ±3.91)mmol/(m2·d);山东半岛东南部海域较高的pCO2受控于温度,同时与黄海沿岸流带来的高碳酸盐等水体的混合有关,表现为大气碳源,平均通量为(0.11 ±0.80)mmol/(m2·d).整个调查海域平均通量为(-2.24 ±3.74)mmol/(m2·d),表现为大气CO2的碳汇.