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991.
Luyu Ding Qikun Lu Lina Xie Jie Liu Wei Cao Zhengxiang Shi 《Journal of the Air & Waste Management Association (1995)》2016,66(3):267-279
The open lots and manure stockpiles of dairy farm are major sources of greenhouse gas (GHG) emissions in typical dairy cow housing and manure management system in China. GHG (CO2, CH4 and N2O) emissions from the ground level of brick-paved open lots and uncovered manure stockpiles were estimated according to the field measurements of a typical dairy farm in Beijing by closed chambers in four consecutive seasons. Location variation and manure removal strategy impacts were assessed on GHG emissions from the open lots. Estimated CO2, CH4 and N2O emissions from the ground level of the open lots were 137.5±64.7 kg hd-1 yr-1, 0.45±0.21 kg hd-1 yr-1 and 0.13±0.08 kg hd-1 yr-1, respectively. There were remarkable location variations of GHG emissions from different zones (cubicle zone vs. aisle zone) of the open lot. However, the emissions from the whole open lot were less affected by the locations. After manure removal, lower CH4 but higher N2O emitted from the open lot. Estimated CO2, CH4 and N2O emissions from stockpile with a stacking height of 55±12 cm were 858.9±375.8 kg hd-1 yr-1, 8.5±5.4 kg hd-1 yr-1 and 2.3±1.1 kg hd-1 yr-1, respectively. In situ storage duration, which estimated by manure volatile solid contents (VS), would affect GHG emissions from stockpiles. Much higher N2O was emitted from stockpiles in summer due to longer manure storage.Implications: This study deals with greenhouse gas (GHG) emissions from open lots and stockpiles. It’s an increasing area of concern in some livestock producing countries. The Intergovernmental Panel on Climate Change (IPCC) methodology is commonly used for estimation of national GHG emission inventories. There is a shortage of on-farm information to evaluate the accuracy of these equations and default emission factors. This work provides valuable information for improving accounting practices within China or for similar manure management practice in other countries. 相似文献
992.
Shi Lu Du Nanshan Yuan Yinghui Shu Sheng Sun Jin Guo Shirong 《Environmental science and pollution research international》2016,23(18):18277-18287
Environmental Science and Pollution Research - Fusarium wilt caused by the fungus Fusarium oxysporum f. sp. cucumerinum (FOC) is the most severe soil-borne disease attacking cucumber. To assess the... 相似文献
993.
初始温度对人粪便好氧堆肥过程的影响 总被引:2,自引:0,他引:2
温度是好氧堆肥过程中需要控制的一个重要因素。不同的初始温度直接影响了堆肥过程中微生物活性及有机物的降解。为了研究初始温度对粪便好氧堆肥过程的影响,采用序批式好氧堆肥反应器,以新鲜锯末为载体,控制含水率在55%~60%的范围左右并强制通风的好氧条件下,进行了初始温度分别为25、35、45和55℃,20 d为一个周期好氧堆肥实验,研究了不同初始温度条件下堆肥过程有机物降解、氮的迁移转化及种子发芽指数的变化。结果表明,初始的高温度会抑制堆肥反应的进行,但初始温度越高,水解效果越显著;初始的高温有利于COD的去除,最终COD的去除率分别为88.2%、89.3%、92.0%和89.9%。初始高温对种子发芽率有抑制作用,同时延迟了堆肥的腐熟期。 相似文献
994.
995.
稻壳生物质炭对水中氨氮的吸附 总被引:6,自引:0,他引:6
以稻壳生物质为原材料,在350℃和500℃2种温度条件下制备生物质炭(BC350和BC500),采用扫面电镜(SEM)和红外光谱(FTIR)对稻壳生物质炭进行了表征。通过实验考查了稻壳生物质炭对氨氮的吸附等温线、影响因素和动态吸附。结果表明,稻壳生物质炭的平衡吸附量随着平衡浓度的增大而增大后趋缓,Langmuir方程比Freundlich方程更好地描述稻壳生物质炭吸附氨氮的行为,BC500比BC350具有更大的吸附氨氮的能力,其最大吸附量分别为5.82 mg/g和6.51 mg/g。p H和离子强度影响BC500对氨氮的吸附效果。动态吸附实验表明,BC500对氨氮的平均吸附量为1.78 mg/g。可见,稻壳生物质炭可以用作高效吸附剂去除废水中的氨氮。 相似文献
996.
采用微波辐照的方法,在混酸条件下对活性碳纤维(ACF)进行改性,制备得到一种改性活性碳纤维(M-ACF).通过小试吸附实验考察了微波功率、溶液pH值对M-ACF吸附Pb(Ⅱ)的影响.通过扫描电子显微镜(SEM)、红外光谱(FTIR)、电子能谱(EDX)等技术对ACF和M-ACF进行表征.结果表明,M-ACF表面的羧基等酸性含氧官能团增多,纤维长度变短且表面粗糙化.当M-ACF的投加量为10 mg、含铅溶液初始浓度为50 mg/L、pH为6、吸附时间为24 h、吸附温度为308 K时,M-ACF对Pb(Ⅱ)的吸附量高达248.5 mg/g.吸附过程符合准二级动力学模型和Langmuir等温吸附模型;热力学参数表明吸附为吸热、自发的过程. 相似文献
997.
以某日化企业在生产过程中产生的洗涤剂废水为处理对象,以接触氧化法为核心工艺,比较了悬挂式组合填料和移动床生物膜反应器(MBBR)悬浮填料对洗涤剂废水的处理效果。实验结果表明:悬挂式组合填料和MBBR悬浮填料的挂膜启动时间分别为13,25 d;当悬挂式组合填料反应器的DO为4.0 mg/L时,COD和LAS的去除率分别为84.33%和89.06%;当MBBR悬浮填料反应器的DO为3.0 mg/L时,COD和LAS的去除率分别为82.54%和90.31%;当MBBR悬浮填料反应器的COD容积负荷为0.5~1.3 kg/(m3·d)时,平均COD去除率为83.91%,继续增大COD容积负荷,COD去除率仍能保持在80%以上;MBBR悬浮填料在COD的高效降解及高浓度有机废水的处理方面优于悬挂式组合填料。 相似文献
998.
Chao Tai Shaodong Zhang Jing Wang Yongguang Yin Jianbo Shi Haoxian Wu Yuxiang Mao 《Environmental Chemistry Letters》2017,15(3):515-523
Singlet oxygen (1O2) and hydroxyl radical (·OH) play an important role in the degradation of pollutants in surface waters. However, the mechanism underlying the photochemical generation of 1O2 and ·OH in wastewaters is poorly known. Here we studied the photo-induced generation of 1O2 and ·OH in different sewage treatment plant units. The correlation between the generation of 1O2 and ·OH and the water constituents was discussed. Our results show that in sewage units the 1O2 formation rate ranges from 2.19 × 10?8 to 6.74 × 10?8 mol L?1 s?1, and the ·OH formation rate ranges from 1.7 × 10?11 to 3.06 × 10?10 mol L?1 s?1. The average 1O2 formation rates in the various sewage units are similar to those in wetland and estuarine waters containing rich dissolved organic matter and 2–4 times higher than those in lake and seawater samples. The average ·OH formation rates of the sewage units are 5–50 times higher than for other water samples reported. The ·OH generation rate increased with the iron content with a correlation coefficient of 0.85, which indicates that the photo-Fenton reaction plays a dominant role in ·OH generation in sewage wastewater. 相似文献
999.
Shi Yusheng Matsunaga Tsuneo 《Environmental science and pollution research international》2017,24(20):16905-16916
Environmental Science and Pollution Research - Biomass burning is a large important source of greenhouse gases and atmospheric aerosols, and can contribute greatly to the temporal variations of CO2... 相似文献
1000.
Chenchen Liu Jiantao Sun Yuewei Liu Hui Liang Minsheng Wang Chunhong Wang Tingming Shi 《Environmental science and pollution research international》2017,24(22):17976-17984
The previous studies estimated the association between PM2.5 (particulate matter with aerodynamic diameter less than or equal to 2.5 μm) exposure during pregnancy and preterm birth, only considered and highlighted the hazard effects of high levels of air pollutant exposure, and underestimated that low levels of pollutant exposure might also affect pregnancy outcome. We conducted a meta-analysis of 11 cohort studies, a total of more than 1,500,000 subjects. The results of these studies were pooled by exposure levels and study periods. PM2.5 exposure during pregnancy was positively associated with preterm birth (OR = 1.15, 95% CI = 1.07–1.23), and during the first trimester of pregnancy, low levels of PM2.5 exposure were also positively associated with preterm birth (OR = 1.17, 95% CI = 1.04–1.30). It is important to protect pregnant women from PM2.5 exposures, especially during their first trimester of pregnancy even when the ambient PM2.5 concentration is relatively low. More relevant health policy should be carried out to prevent hazard effect of air pollutants. 相似文献