二氧化钛载银抗菌剂的研究进展

介绍了二氧化钛系和银系无机抗菌剂在国内外的研究现状、杀菌机理以及存在的问题,论述了二氧化钛载银改性杀菌材料的最新进展,并就其研究开发亟需解决的关键问题提出了可行性建议。     

Simulation of global warming potential (GWP) from rice fields in the Tai-Lake region,China by coupling 1:50,000 soil database with DNDC model

Quantifying greenhouse gas (GHG) emissions from wetland ecosystems is a relatively new issue in global climate change studies. China has approximately 22% of the world's rice paddies and 38% of the world's rice production, which are crucial to accurately estimate the global warming potential (GWP) at regional scale. This paper reports an application of a biogeochemical model (DeNitrification and DeComposition or DNDC) for quantifying GWP from rice fields in the Tai-Lake region of China. For this application, DNDC is linked to a 1:50,000 soil database, which was derived from 1107 paddy soil profiles compiled during the Second National Soil Survey of China in the 1980–1990s. The simulated results show that the 2.34 Mha of paddy soil cultivated in rice–wheat rotation in the Tai-Lake region emitted about ?1.48 Tg C, 0.84 Tg N and 5.67 Tg C as CO₂, N₂O, and CH₄ respectively, with a cumulative GWP of 565 Tg CO₂ equivalent from 1982 to 2000. As for soil subgroups, the highest GWP (26,900 kg CO₂ equivalent ha^?1 yr^?1) was linked to gleyed paddy soils accounting for about 4.4% of the total area of paddy soils. The lowest GWP (5370 kg CO₂ equivalent ha^?1 yr^?1) was associated with submergenic paddy soils accounting for about 0.32% of the total area of paddy soils. The most common soil in the area was hydromorphic paddy soils, which accounted for about 53% of the total area of paddy soils with a GWP of 12,300 kg CO₂ equivalent ha^?1 yr^?1. On a regional basis, the annual averaged GWP in the polder, Tai-Lake plain, and alluvial plain soil regions was distinctly higher than that in the low mountainous and Hilly soil regions. As for administrative areas, the average annual GWP of counties in Shanghai city was high. Conversely, the average annual GWP of counties in Jiangsu province was low. The high variability in soil properties throughout the Tai-Lake region is important and affects the net greenhouse gas emissions. Therefore, the use of detailed soil data sets with high-resolution digital soil maps is essential to improve the accuracy of GWP estimates with process-based models at regional and national scales.     

办公建筑夏季用能行为测试研究

建筑使用者热环境改善行为对建筑能耗具有重要影响。对杭州市某办公建筑开展夏季空调使用行为测试。较高的空调使用率以及空调设备对室内热环境的显著改善说明空调使用是该地区夏季采用的主要降温措施。采用逻辑回归构建出夏季空调开启率预测模型。根据所构建的夏季空调开启率预测模型,得出测试房间空调开启室外耐受温度为32.0℃。根据测试期间空调开启时刻温度,得出空调开启室内耐受温度为28.7℃。     

Trametes sp.LS-10C漆酶对直接类偶氮染料的脱色作用

利用栓菌（Trametes sp.LS-10C）漆酶在单酶和漆酶-介体体系2种情况下对3种直接类偶氮染料进行脱色。结果表明,在给酶量为10 U·mL-1、染料浓度为100 mg·mL-1条件下反应24 h后,直接蓝86在非介体体系中脱色率达到71.2%,其最适脱色温度和pH范围分别为45~60℃和3.5~5.0;直接橙26在介体体系（10 μmol·L-1 ABTS）中脱色率达到78.7%,其最适脱色温度和pH范围分别为35~45℃和4.5~6.5;直接红31在介体体系（10 μmol·L-1 ABTS）中脱色率达到90.7%,其最适脱色温度和pH范围分别为35~45℃和3.5~5.0。     

绿色木霉和黄孢原毛平革菌混合降解稻草秸秆中的VOCs

利用黄孢原毛平革菌和绿色木霉混合培养降解稻草秸秆,使用顶空固相微萃取气质联用的方法研究了降解过程中产生的挥发性有机物,并对混合培养中同一平板上不同区域产生的挥发性有机物进行了比较。纯培养和混合培养中挥发性有机物的对比研究表明,两株菌的混合培养较其纯培养有更强地降解稻草的能力。在混合培养过程中检测到C15H24的两种同分异构体,分别属于双环倍半水芹烯和环己二烯类物质,均是倍半萜烯,证实了黄孢原毛平革菌和绿色木霉混合培养时的拮抗机制。同时发现环己二烯类物质仅在混合培养中的混合区域检测到,表明混合培养中混合区域较之非混合区域具有更强的竞争表现,分区域检测降解过程中挥发性有机物能更好地研究混合接种的降解机理。     

废弃铬盐厂土壤中铬的赋存特征及异位淋洗修复可行性研究

土壤理化性质、污染物的分布及赋存特征是土壤异位淋洗技术是否可行的关键依据。以西北某废弃铬盐厂铬污染场地土壤作为研究对象,测定了土壤基本理化参数及各粒径污染物的浓度,探究总铬和六价铬在不同粒径土壤中的分布特征,并通过铬的赋存形态分析确定清水作为淋洗剂,开展异位清水淋洗实验。结果表明：供试土壤粗颗粒物料（粒径分别为：>9.50 mm、2.00~9.50 mm、0.841~2.00 mm及0.25~0.841 mm）占土壤总质量的比例达到93.36%,总铬和六价铬污染物富集于土壤细颗粒（粒径-1,达到修复标准要求。     

响应面法优化石油降解菌性能的研究

从延长油田石油污染土壤中筛选出4株能以原油为唯一碳源生长的细菌单菌株,鉴定其优势菌株YC-2为枯草芽孢杆菌;利用响应面法进行实验设计,选定培养温度、pH值、氮磷比以及盐度为影响因素,对原油含量为0.5%的培养基进行YC-2菌株降解工艺优化,得到了原油降解率与4种因素之间的非线性回归方程,确定了降解原油的最优工艺条件:培养温度28℃;pH值6.5,氮磷比5.2:1,盐度0.45%。在最优条件下,预测降解率为53.9%,实验验证值为52.5%,结果显示,建立的模型具有较高的精度。     

天津市某污水处理厂脱氮效率的评价

城市污水处理厂作为城市污水处理的重要承担者,其处理能力不足势必会对下游水体产生严重影响,也给水体的再生利用带来了难度,污水处理厂的去除效率变得尤为关注。以2014年3-12月天津市某污水处理厂氮的监测数据为基础,对其脱氮效率进行了评价。结果表明:污水处理厂脱氮效率偏低,总氮平均去除率为55.61%,且出水仅达到二级排放标准(GB 18918-2002),水厂进水C/N、水温对总氮的去除效率影响很大;水厂氨氮的平均去除率为87.40%,其去除率受进水NH4+-N浓度影响很大,水厂对高浓度的进水NH4+-N(大于70 mg/L)去除效率偏低,而进水NH4+-N小于60 mg/L时,出水NH4+-N基本能满足一级A排放标准(GB 18918-2002);水厂出水的亚硝态氮含量很高,其主要受溶解氧和C/N的影响;水厂对有机氮的去除效果不佳,需要采用深度处理技术。     

Potential of fly ash for neutralisation of acid mine drainage

Lignite (PK), bituminous (FI) and biomass (SE) fly ashes (FAs) were mineralogically and geochemically characterised, and their element leachability was studied with batch leaching tests. The potential for acid neutralisation (ANP) was quantified by their buffering capacity, reflecting their potential for neutralisation of acid mine drainage. Quartz was the common mineral in FAs detected by XRD with iron oxide, anhydrite, and magnesioferrite in PK, mullite and lime in FI, and calcite and anorthite in SE. All the FAs had high contents of major elements such as Fe, Si, Al and Ca. The Ca content in SE was six and eight times higher compared to PK and FI, respectively. Sulphur content in PK and SE was one magnitude higher than FI. Iron concentrations were higher in PK. The trace element concentrations varied between the FAs. SE had the highest ANP (corresponding to 275 kg CaCO₃?tonne^?1) which was 15 and 10 times higher than PK and FI, respectively. The concentrations of Ca²⁺, SO₄ ^2?, Na⁺ and Cl^? in the leachates were much higher compared to other elements from all FA samples. Iron, Cu and Hg were not detected in any of the FA leachates because of their mild to strong alkaline nature with pH ranging from 9 to 13. Potassium leached in much higher quantity from SE than from the other ashes. Arsenic, Mn and Ni leached from PK only, while Co and Pb from SE only. The concentrations of Zn were higher in the leachates from SE. The FAs used in this study have strong potential for the neutralisation of AMD due to their alkaline nature. However, on the other hand, FAs must be further investigated, with scaled-up experiments before full-scale application, because they might leach pronounced concentrations of elements of concern with decreasing pH while neutralising AMD.     

臭氧活性炭-后置砂滤工艺对水中农药的控制效能

选择我国饮用水水质标准中有相关规定,以及部分用量较大或虽被禁用但仍有残留的农药共25种,对黄浦江水源水以及采用臭氧活性炭-后置砂滤工艺的某水厂工艺段出水中的浓度分布进行了调查,评估了砂滤后置工艺条件下相应农药的实际处理效果。结果表明:原水中有包括莠去津、乐果、六氯苯、敌敌畏、乙草胺、丁草胺、仲丁威和p,p'-DDT的8种农药检出,且总浓度较高达到760 ng/L,其中莠去津和乙草胺含量较高,最高浓度分别达到531 ng/L和277 ng/L;从季节性分布来看,春季总农药浓度最高达760 ng/L,秋季最低为175 ng/L。从工艺去除效果来看,臭氧活性炭砂滤后置工艺对农药的总体去除率为62%~78%,与冬春季相比,夏秋季节的农药的去除率提高约10%左右,这可能与高温期微生物活性较高有关。值得关注的是,砂滤后置工艺与同期常规臭氧活性炭工艺相比农药的总去除率要低10%左右,应结合总体出水水质情况对其进一步评估。