OH自由基引发的甲烷光化学氧化体系中有机过氧化物的研究

在１．０１３２５×１０＾５Ｐａ,２９８Ｋ,Ｏ２－Ｎ２气氛下,采用长光路付立叶红外光谱仪跟踪反应进程,高压液相色谱仪测定反应产物中有机过氧化物,研究了ＯＨ自由基基引发的甲烷光化学反应体系,证实反应产物中有Ｈ２Ｏ２、甲基过氧化氢（ＣＨ３Ｏ２Ｈ,ＭＨＰ）和过氧甲醚（ＣＨ３Ｏ２ＣＨ３）,并发现羟甲基过氧化氢（ＨＯＣＨ２ＯＯＨ,ＨＭＨＰ）和一未知有机过氧化物,ＨＭＨＰ的发现表明ＣＨ４氧化过程中可能存在过氧甲     

水田中甲烷的发生,释放机制及其削减对策

ＣＨ４是温度效应气体之一，人类的生活和生产活动导致大气中ＣＨ４浓度的增加，通过水田中ＣＨ４的发展，释放机制的研究方法，以及近期研究成果的介绍，提出了控制ＣＨ４发生量的有关技术问题及应采取的有效措施。     

Response of CH4 emission of paddy fields to land management practices at a microcosmic cultivation scale in China

The terrestrial ecosystem may be either a source or a sink of CH4 in rice paddies, depending, to a great extent, on the change of ecosystem types and land use patterns. CH4 emission fluxes from paddy fields under 4 cultivation patterns (conventional plain culture of rice(T1), no-tillage and ridge culture of rice(T2), no-tillage and ridge culture of rice and wheat (T3), and rice-wheat rotation(T4)) were measured with the closed chamber technique in 1996 and 1998 in Chongqing, China. The results showed that differences existed in CH4 emission from paddy fields under these land management practices. In 1996 and 1998, CH4 emission was 71.48% and 78.82% (T2), 65.93% and 57.18% (T3), and 61.53% and 34.22% (T4) of that in T1 during the rice growing season. During the non-rice growing season, CH4 emission from rice fields was 76.23% in T2 and 38.69% in T]. The accumulated annual CH, emission in T2, T3 and T4 in 1996 decreased by 33.53%, 63.30% and 65.?3%, respectively, as compared with that in TI. In 1998. the accumulated annual CH4 emission in T], T2, T3 and T4 was 116.96g/m^2, 68.44g/m^2, 19.70g/ms and 11.80g/m^2, respectively. Changes in soil physical and chemical properties, in thermal and moisture conditions in the soil and in rice plant growth induced by different land use patterns were the dominant causes for the difference in CH4 emission observed. The relative contribution of various influencing factors to CH, emission from paddy fields differed significantly under different land use patterns. However, the general trend was that chlorophyll content in rice leaves, air temperature and temperature at the 5 cm soil layer play a major role in CH4 emission from paddy fields and the effects of illumination, relative humidity and water layer depth in the paddy field and CH4 concentration in the crop canopy were relatively non-significant. Such conservative land use patterns as no-tillage and ridge culture of rice with or without rotation with wheat are thought to be beneficial to reducing CH4 emission from paddy fields and are, therefore, recommended as a significant solution to the problems of global(climatic) change.     

测定固定污染源废气中非甲烷总烃的问题探讨

以HJ/T 38-1999为基础,针对气相色谱法测定污染源废气中非甲烷总烃存在的诸多问题进行探讨,在总烃出峰峰形、废气氧峰值测定、高沸点物质干扰等方面做了研究试验。结果表明,1ml定量环容易造成总烃出现平头峰,改成0.25ml定量环能得到好的峰形;非甲烷总烃的检出限为0.04 mg/m~3(以碳计);氧峰值与氧量具有线性关系,应根据氧量判断氧峰值大小,而不是统一扣除除烃空气氧峰值;废气中存在高沸点组分时,容易吸附于采样容器内壁,将样品加热至100℃再测试可提高该组分的检出率。     

低热值污泥与油脂共消化强化甲烷产量及微生物组分探究

低热值污泥由于有机质含量低而限制了其厌氧消化甲烷的产量。研究报道了一种强化低热值污泥厌氧消化产甲烷的新方法,即低热值污泥与油脂共消化。结果表明:低热值污泥与油脂共消化能够促进甲烷的产量,并且污泥和油脂的最佳比例为1∶1,且投加0.5 L混合物时,其相应的甲烷产量为1 250 m L。进一步研究发现污泥和油脂共消化能够促进挥发性脂肪酸的积累和有机质的减量。微生物群落结构组分分析表明:污泥和油脂共消化可促进Methanosarcina的丰度,而降低Methanoculleus的丰度。在污泥和油脂最佳混合比例下,Methanosarcina和Methanoculleus的丰度分别为64.8%和2.3%。     

天津市生活污水甲烷排放量估算研究

气候变化问题是当前人类发展面临的重要挑战,甲烷作为重要的温室气体来源,其引起气候变化的作用不容小觑。污水处理甲烷排放是全球重要的甲烷排放源,并且增长快、减排潜力较大。生活污水中BOD含量是甲烷排放量核算中重要的活动水平数据,而我国又缺乏BOD统计量,需要尽快形成BOD/COD地方特征值以便更加准确地估算生活污水甲烷排放量,并为各省市温室气体清单的编制提供基础数据支持。本文通过天津市2012-2015年污水处理厂BOD/COD实测数据估算得出各年度天津市系统处理与排入环境污水的BOD/COD特征值,据此估算各年生活污水甲烷排放量。最终,结合估算结果提出污水处理部门温室气体减排对策建议。     

海域天然气水合物分布地震预测技术研究现状及展望

据预测,我国海域蕴藏着非常丰富的天然气水合物资源。今年在神狐海域成功进行了为期两个月的试采工作,试采日产气量呈现了逐渐下降趋势,可见我国在有关天然气水合物分布预测的技术方面还不成熟。通过对国内外相关文献的分析研究,从量化角度综述了三类海域天然气水合物分布预测技术:定性预测技术、半定量预测技术、定量预测技术。最后,对未来海域天然气水合物定量分布预测技术的趋势进行了展望。