有机硅憎水改性珍珠岩复合保温材料的制备及性能研究

利用有机硅憎水剂对珍珠岩进行憎水改性处理,并将改性后的珍珠岩分别与聚乙烯醇(PVA)、脲醛树脂(UF)以及三聚氰胺脲醛树脂(MUF)进行填充复配制得三种复合材料,采用标准试验方法测定了三种憎水改性复合材料的密度、燃烧性能、烟密度、氧指数、导热系数等相关特性参数,考察了不同配比下的材料的导热性能和燃烧性能。结果表明,改性处理后珍珠岩复合材料的阻燃性能均有效增强,且表现出一定的协同效应。采用PVA的复合材料密度最低,为185.8kg/m~3;导热系数最低,为0.046w/m·k;烟密度仅10%;受热分解慢。而采用UF和MUF时其复合材料均表现出良好的阻燃特性,MUF复合材料氧指数达到了52.5%。     

港口环境风险管理探讨——以天津港为例

中国是一个海洋大国,海洋和港口的环境保护得到了国家的高度重视。港口的环境风险防范管理是一个较新的研究领域,当前中国港口经济的高速增长必然带来港口环境风险的增加,对风险进行有效地评价和管理对国家的经济发展和环境保护具有重要意义。本文对天津港环境风险管理的过程进行了较为系统的探讨,分析了天津港环境风险管理技术思路和主要内容,对天津港存在的环境风险因子做了识别,并对环境风险的评估方法做了针对性总结,为港口的风险防范措施提供了一些建议。     

浅谈石油化工厂罐区的火灾特点及扑救对策

分析了石油化工厂罐区的火灾特点,提出了火灾扑救的对策。     

Na型斜发沸石去除水中铁锰及其再生方法研究

为建立一种简单、有效、应用性强的地下水除铁锰方法,研究了Na型斜发沸石除铁锰及其影响因素并建立了再生方法.研究表明Na型斜发沸石对Fe(Ⅱ)和Mn(Ⅱ)均表现出较强的吸附能力,对Fe(Ⅱ)和Mn(Ⅱ)的最大饱和吸附量分别达4.00 mg/g和3.50 mg/g;且吸附速率快,吸附动力学较好地符合Lagergren一级吸附动力学模型.采用Langmuir吸附等温线能较好描述Bio-F吸附Fe(Ⅱ)(R2=0.981 4)及Mn(Ⅱ)(R2=0.989 9)的过程.该吸附剂在pH6～7范围内可保持90%以上吸附Fe(Ⅱ)和Mn(Ⅱ)的能力.Na型斜发沸石可用15%的NaCl溶液再生,10次再生实验证明其吸附容量可保持100%,研究表明该方法用于高铁锰饮用水处理具有较强的应用价值.     

石油化工放射工作人员细胞遗传学分析研究

目的分析研究长期接触射线的石油化工放射工作人员细胞遗传学改变,评价x、y、中子射线对人体细胞遗传学影响.方法染色体培养采用微量全血培养法;微核测定采用常规培养法.结果射线组人员染色体畸变率为0.28%,微核细胞率为3.23‰,明显高于对照组(0.145%.0.165‰),两组间比较有非常显著性差异(P＜0.01).结论不同射线工龄组、不同放射应用专业人员的染色体畸变率、淋巴细胞微核率均明显高于对照组,差异有非常显著性.     

农村环境质量影响因素量化分析模型研究

通过对山阴县40个村庄的实际调查,分析影响农村环境质量的主要影响因素,建立多元回归模型,得出了农村居民人均纯收入、国家环保事业的资金投入、中国农村家庭的主要能源结构为主要影响因素,并通过实例验证该模型的可行性。     

中国森林土壤微生物动态变化研究进展

土壤微生物是森林生态系统的基本组成部分,在物质能量循环中起着十分重要的作用。根据目前中国森林土壤微生物的研究现状,分别在土壤微生物的分布特征、区系组成特征和动态变化影响因素等方面进行归纳和总结,以期发现森林环境下土壤微生物的动态变化规律,为今后的土壤微生物生态学的研究和发展奠定基础。     

Effects of activated sludge flocs and pellets seeds on aerobic granule properties

Aerobic granules seeded with activated sludge flocs and pellets (obtained from activated sludge flocs) were cultivated in two sequencing batch reactors and their characteristics were compared. Compared with granules seeded with activated sludge flocs, those seeded with pellets had shorter start-up time, larger diameter, better chemical oxygen demand removal e ciency, and higher hydrophobicity, suspended solid concentration, and Mg2+ content. The di erent inocula led the granule surface with di erent microbial morphologies, but did not result in di erent distribution patterns of extracellular polymeric substances and cells. The anaerobic bacterium Anoxybacillus sp. was detected in the granules seeded with pellets. These results highlighted the advantage of pellet over activated sludge floc as the seed for aerobic granulation and wastewater treatment.     

N2O and NH3 emissions from a bioreactor landfill operated under limited aerobic degradation conditions

The combination of leachate recirculation and aeration to landfill may be an efficient way for in-situ nitrogen removal. However, nitrogenous substances contained in the landfill layer are concomitantly transformed into N2O and NH3, leading to increased emissions into the atmosphere. In the present study, the emissions of N2O and NH3 were measured under conditions of fresh or partially stabilized refuse with or without leachate recirculation or intermittent aeration. The results showed that the largest N2O emission (12.4 mg-N/L of the column) was observed in the aerated column loaded with partially stabilized refuse and recycled with the leachate of low C/N ratio; while less than 0.33 mg-N/L of the column was produced in the other columns. N2O production was positively correlated with the prolonged aerobic time and negatively related with the C/N ratio in the recycled leachate. NH3 volatilization increased with enhanced gas flow and concentration of free ammonia in the leachate, and the highest cumulative volatilization quantity was 1.7 mg-N/L of the column.     

Two selenium tolerant Lysinibacillus sp. strains are capable of reducing selenite to elemental Se efficiently under aerobic conditions

Microbes play important roles in the transport and transformation of selenium (Se) in the environment, thereby influencing plant resistance to Se and Se accumulation in plant. The objectives are to characterize the bacteria with high Se tolerance and reduction capacity and explore the significance of microbial origins on their Se tolerance, reduction rate and efficiency. Two bacterial strains were isolated from a naturally occurred Se-rich soil at tea orchard in southern Anhui Province, China. The reduction kinetics of selenite was investigated and the reducing product was characterized using scanning electron microscopy and transmission electron microscopy-energy dispersive spectroscopy. The bacteria were identified as Lysinibacillus xylanilyticus and Lysinibacillus macrolides, respectively, using morphological, physiological and molecular methods. The results showed that the minimal inhibitory concentrations (MICs) of selenite for L. xylanilyticus and L. macrolides were 120 and 220 mmol/L, respectively, while MICs of selenate for L. xylanilyticus and L. macrolides were 800 and 700 mmol/L, respectively. Both strains aerobically reduced selenite with an initial concentration of 1.0 mmol/L to elemental Se nanoparticles (SeNPs) completely within 36 hr. Biogenic SeNPs were observed both inside and outside the cells suggesting either an intra- or extracellular reduction process. Our study implied that the microbes from Se-rich environments were more tolerant to Se and generally quicker and more efficient than those from Se-free habitats in the reduction of Se oxyanions. The bacterial strains with high Se reduction capacity and the biological synthesized SeNPs would have potential applications in agriculture, food, environment and medicine.