Potentials for Combating Desertification in Hunshandak Sandland Through Nature Reserve

Desertification directly threatens more than 250 million people and one third of the earths land surface. Although it is well known that desertification could be reversed in most cases if the intensity of land use were reduced, there have been no studies on how to achieve this reversed desertification on a large scale. We conducted a case study in Hunshandak Sandland of North China, exploring how creation of a nature reserve might aid restoration of a degraded ecosystem. Experimental data indicated that desertified regions, if designated as a nature reserve, could be restored with conservation of biodiversity. The buffer zones in moderately desertified lands could serve as a base for forage production and/or ecotourism industry. The construction of ecologically designed towns (ecotowns) in transition zones could accommodate migrants moved from core zones so as to develop stock production, related industry, and ecotourism, enabling both economic and environmental development. Up to now, 5778 local inhabitants in the core zones of Zhenglan Banner (county) in the Hunshandak Sandland have been moved out of the severely degraded areas with the financial assistance of the central government. Those people have been moved into three eco-towns of the Banner with an objective of greatly enhancing the economic and social status while restoring the degraded sandlands.     

脱硫MEC的硫价态变化与微生物群落演替规律

采用微生物电解池(microbial electrolysis cell,MEC)进行沼气脱硫研究,探究了阳极的S2-去除率、硫价态的变化及微生物群落演替规律.结果 表明,该方法中S2-去除率可达到90％以上,SO42-为阳极硫氧化反应的主要产物.微生物群落分析结果表明,Pseudomonas为脱硫优势微生物,在阳极生...     

催化湿式氧化中多相非贵金属催化剂的研究进展

催化湿式氧化（CWAO）法是一种利用溶解氧去除废水中高毒性、难降解污染物的新型水处理技术。在催化湿式氧化中应用的催化剂有贵金属催化剂和非贵金属催化剂两种。在零附加值的废水处理过程中,使用非贵金属催化剂替代贵金属催化剂,在经济上更具有优势。对近年来用于催化湿式氧化废水处理过程中的多相非贵金属催化剂进行了综述。     

氟污染区土壤中水溶氟与总氟土壤性质的相关性

对氟污染区土壤中水溶氟与总氟、土壤性质的相关性研究表明:污染区土壤中水溶氟与总氟(r=0.9272)、交换性铝(r=0.7103)、有机质(r=0.5551)之间呈非常显著正相关性(p<0.01),而与交换性钙(r=-0.6424)、pH值(r=-0.5431)呈非常显著负相关性(p<0.01)。     

高盐度有机废水对生物处理系统的影响研究进展

高盐度有机废水是一种难处理的废水,如皂素废水、石油开采废水以及海水直接利用后排放出的废水,主要是因为高含盐量对微生物的生长有很强的抑制作用,严重抑制了生物法在高盐度废水处理中的应用。讨论了国内外对含高盐有机废水生化处理技术的研究进展以及盐对生物处理系统的影响,并全面分析了高盐度有机废水生物处理的可行性。     

磺酰脲类除草剂DPX-E9636的水解机理

对室温下ＤＰＸ－Ｅ９６３６的水解产物分离纯化后,运用元素分析,紫外光谱及＾１Ｈ核磁共振鉴定了主要产物的结构。产物为：１－（４,６－二甲氧基嘧啶基－２）－３（乙磺酰基－２－吡啶基）脲、Ｎ－（４,６－二甲氧基嘧啶基－２）－３－乙磺酰基－２－胺基吡啶、３－乙磺酰基－２－胺基吡啶及２－胺基－４,６－二甲氧基嘧啶,由此推测了ＤＰＸ－Ｅ９６３６的水解机理。     

用电解法从富集氰化废液中回收铜的研究

叙述了从富集氰化废液中电解回收铜的试验研究结果。通过电极材料、电流密度、离子共沉积、游离氰、电解时间、温度和极间距等一系列试验,探索电解过程中各项最佳条件,为工业电解提供可靠的工艺参考。      

氮肥使用对北方夏玉米季氨挥发的影响

氨挥发是农田作物生产中氮肥损失的主要途径之一,对空气质量有重要影响.为研究我国北方地区化肥类型、施用数量、施氮时期以及采样方法等因素对夏玉米季氨挥发的影响,本研究收集了1980~2018年发表的北方地区夏玉米生产中氨挥发的研究文献,并对数据进行统计分析.结果发现,随着化肥施氮量的增加,氨挥发总量呈指数型增长,净氨挥发量呈幂函数型增长.基肥/追肥施氮量为1/1时,追肥期氨挥发总量和净氨挥发量显著高于基肥期（P<0.05）,氨挥发总量分别约占总生育期的58.4%和41.6%.随着施氮量的增加,激发效应先表现为负效应后逐渐转变为正效应,转折点施氮量为297 kg ·hm^-2.采用抽气法与海绵法测定的氨挥发量存在显著差异（P<0.01）,且抽气法测定数据更为稳定.施用缓释尿素相较于普通尿素可降低氨挥发约20%~50%.我国北方夏玉米生产中,合理控制追肥期施氮量更有助于减少氨挥发,且高氮肥条件下抽气法比海绵法更适合于氨挥发的测定.     

Association between particulate matter air pollution and cardiovascular disease mortality in Lanzhou,China

Ambient particulate matter (PM) pollution has been linked to elevated mortality, especially from cardiovascular diseases. However, evidence on the effects of particulate matter pollution on cardiovascular mortality is still limited in Lanzhou, China. This research aimed to examine the associations of daily mean concentrations of ambient air pollutants (PM_2.5, PM_C, and PM₁₀) and cardiovascular mortality due to overall and cause-specific diseases in Lanzhou. Data representing daily cardiovascular mortality rates, meteorological factors (daily average temperature, daily average humidity, and atmospheric pressure), and air pollutants (PM_2.5, PM₁₀, SO₂, NO₂) were collected from January 1, 2014, to December 31, 2017, in Lanzhou. A quasi-Poisson regression model combined with a distributed lag non-linear model (DLNM) was used to estimate the associations. Stratified analyses were also performed by different cause-specific diseases, including cerebrovascular disease (CD), ischemic heart disease (IHD), heart rhythm disturbances (HRD), and heart failure (HF). The results showed that elevated concentration of PM_2.5, PM_C, and PM₁₀ had different effects on mortality of different cardiovascular diseases. Only cerebrovascular disease showed a significant positive association with elevated PM_2.5. Positive associations were identified between PM_C and daily mortality rates from total cardiovascular diseases, cerebrovascular diseases, and ischemic heart diseases. Besides, increased concentration of PM₁₀ was correlated with increased death of cerebrovascular diseases and ischemic heart diseases. For cerebrovascular disease, each 10 μg/m³ increase in PM_2.5 at lag4 was associated with increments of 1.22% (95% CI 0.11–2.35%). The largest significant effects for PM_C on cardiovascular diseases and ischemic heart diseases were both observed at lag0, and a 10 μg/m³ increment in concentration of PM_C was associated with 0.47% (95% CI 0.06–0.88%) and 0.85% (95% CI 0.18–1.52%) increases in cardiovascular mortality and ischemic heart diseases. In addition, it exhibited a lag effect on cerebrovascular mortality as well, which was most significant at lag6d, and an increase of 10 μg/m³ in PM_C was associated with a 0.76% (95% CI 0.16–1.37%) increase in cerebrovascular mortality. The estimates of percentage change in daily mortality rates per 10 μg/m³ increase in PM₁₀ were 0.52% (95% CI 0.05–1.02%) for cerebrovascular disease at lag6 and 0.53% (95% CI 0.01–1.05%) for ischemic heart disease at lag0, respectively. Our study suggests that elevated concentration of atmospheric PM (PM_2.5, PM_C, and PM₁₀) in Lanzhou is associated with increased mortality of cardiovascular diseases and that the health effect of elevated concentration of PM_2.5 is more significant than that of PM_C and PM₁₀.

     

转盘式光催化燃料电池处理染料废水

采用阳极氧化法制备转盘式TiO_2阳极,设计并开发了转盘式光催化燃料电池(PFC),探讨了圆盘转速对PFC中染料降解效果的影响。实验结果表明:随着圆盘转速的提高,污染物和光电界面反应产物的传质作用得以强化,罗丹明B降解率提高;在圆盘转速为1 600 r/min、反应时间为60 min的条件下,罗丹明B降解率达90.8%,是圆盘转速为0 r/min时的8.5倍;光电流也随着圆盘转速的提高而提高,但提高幅度远小于罗丹明B降解率的提高幅度;同时,加强传质作用后再外加电压对PFC催化降解性能的提高作用有限。