黄泔水发酵微生物絮凝剂B-12的研究

以黄泔水为廉价培养基,对絮凝剂产生菌B-12进行发酵培养,用单因素实验和正交设计试验,考察了培养基条件对絮凝剂产生菌絮凝效果的影响。结果表明:B-12的优化培养条件为:黄泔水体积分数为12.5%,硫酸铵为0.5g/L,温度为28℃,初始培养pH为6.5。在此条件下所产生的絮凝剂对高岭土悬液絮凝率高达81.2%。利用黄泔水生产的微生物絮凝剂B-12对化粪池废水、城市生活污水和土壤悬浊液具有良好的絮凝效果。     

Decontamination of anaerobically digested slurry in a paddy field ecosystem in Jiaxing region of China

Anaerobic digestion has become increasing popular for managing biowastes in rural China as it has the advantage of generating biogas, a renewable energy. A new challenge, however, is minimizing the environmental pollution resulting from the anaerobically digested slurry (ADS). The aim of this study was to assess the feasibility of using a paddy field to remediate ADS while simultaneously cultivating rice. A field experiment was trialed using six treatments based on varying nitrogen loadings over the period of a rice-growing season. These treatments were adjusted to the content of the N within the ADS and had loadings of 270, 405, 540 and 1080 kg N ha⁻¹. These treatments were compared to a negative control (no fertilizer) and a positive control (chemical fertilizer) that consisted of urea applied at 270 kg N ha⁻¹. The effects of these N sources and slurry remediation were monitored using standard methods to measure water quality, soil properties and changes in rice production. Rice grain yields were generally higher for all ADS treatments than for the urea N treatment. Standing water quality in the field could reach national discharge standards for all treatments within 7-8 days after each ADS irrigation. Groundwater quality and heavy metal concentrations in both soil and the rice grain were not affected by the ADS treatments. We suggest that the quantities of ADS irrigated in 867-1734 m³ ha⁻¹ was not only safe for food quality (rice grain) and the receiving environment (water and soil), but also beneficial to soil fertility and rice grain yield.     

多氯联苯污染土壤热脱附预处理过程干化及排放特性研究

利用桨叶式干化实验装置对多氯联苯(PCBs)污染土壤热脱附预处理过程的干化特性进行了研究,结果表明干化温度和搅拌速率的提高均有助于加速干化速率;水分的内部扩散是PCBs污染土壤干化速率的主要影响因素.文章还结合高分辨色谱/质谱联用仪研究了PCBs污染土壤预处理过程中多氯联苯的排放特性,结果显示干化温度升高会促进4氯代到7氯代联苯的释放,并且会增加气相PCBs毒性当量(TEQ) 以及PCBs总量排放百分率.考虑安全和干化效果,干化温度选择在200 ℃以下为宜.     

大学生旅游者环境意识水平调查研究

环境意识水平的提升能从根本上改变大学生旅游者传统的思维方式和价值观,内在自觉地规范旅游环境行为和实践活动。以南京林业大学为研究对象,以配额抽样法探讨大学生旅游者学科专业、性别因素对环境意识的影响,研究发现大学生旅游者表现出较好的环境态度和倾向,对旅游环境和生态知识的渴求和认知程度对其整体环境意识水平有较大影响,然而也存在着知行脱节,环境行为滞后于环境情感、意志的现象。应重视高校环境教育工作,努力提升大学生旅游者的环境意识水平。     

Fine Dust Filtration Using a Metal Fiber Bed

Abstract

A bed-type filter composed of thin metal alloy fiber was closely examined with dust capturing in cold and hot runs. The investigation of an individual mechanism across the filter bed indicated that the aerated dust could be initially collected by depth filtration, and after a while, surface filtration dominated the overall dust collection. The present metal fiber bed was comparable to the conventional ceramic filters because of its good collection efficiency with low pressure drop. It also showed potential to be used as a prefilter in a diesel exhaust trapping system.     

Biodegradability of Banana and Plantain Cellulose Microfibrils Films in Anaerobic Conditions

Currently, cellulose microfibrils are being investigated as nanofillers for polymers to increase their biodegradability. However, until now there has been no report on their degradability by microorganisms. In this work the anaerobic degradation of cellulose microfibril films extracted from banana and plantain plant rachis residues has been studied. Samples were exposed to burial tests in nature compost during 14?days. Changes due to the degradation process were investigated by techniques as optical microscopy, tensile tests, viscosity measurements, ATR-FTIR spectroscopy, X-ray diffraction and thermogravimetric analysis. Biodegradability was higher for cellulose microfibril films extracted from banana (BCMF) than plantain films (PCMF). Growth of microorganism colonies on BCMF films and just yellowing on PCMF films was observed by microscopic analysis. New bands characteristic of aldehyde functional groups due to the breaking of ??-(1,4)-glycosidic bonds were observed in infrared spectra. This breakage was also responsible for the fall-down of mechanical properties and polymerization degree. X-ray diffraction and thermogravimetric analysis showed that BCMF films were at the first stage of degradation for the used burial test times because the microorganisms only attacked the amorphous cellulose leading to a slight increase in crystallinity. In the case of PCMF films this variation remained practically invariant.     

Assessing the impact of petrol stations on their immediate surroundings

This paper describes a novel methodology for evaluating the extent to which petrol stations affect their surroundings. The method is based on the fact that the ratio of the concentrations of aliphatic and aromatic hydrocarbon pollutants in the air of the petrol stations and their surroundings (basically determined by vapor emissions from unburned gasoline) differs from the ratio found in urban air, which is mainly influenced by traffic emissions. Bearing this in mind, the spatial limit of influence of petrol stations in any direction would be the first point, moving away from the station, where the ratio becomes equal to the urban background ratio. Application of the methodology involves multipoint measuring campaigns of the air at the studied petrol station and built-up area in general and processing the data with software capable of providing isoconcentration contours. The procedure should help local authorities in terms of land management, so that a “belt” can be established around petrol stations where housing or vulnerable populations and activities such as those in schools, hospitals and community centers should be restricted.     

雾化电晕净化烹调油烟技术

对雾化电晕放电极雾化过程、荷电液滴的捕集原理、自清洗作用进行探讨,在相同电压下雾化负电晕放电电流高于干式负电晕放电电流,极间大量荷电液滴具有很高的荷质比,并高速向极板驱进,对烟尘具有静电凝并和动力凝并除尘作用,具有高效净化油烟、自清洗极板的功能,此项净化烹调油烟的新技术,优于传统油烟净化技术,具有很好的应用价值和前景.     

Bioaccumulation and changes of trace metals over the last two decades in marine organisms from Guangdong coastal regions, South China

Trace metal (Cr, Ni, Cu, Zn, Cd and Pb) exposures, distribution and bioaccumulation were investigated in marine organisms from Guangdong coastal regions, South China. The results showed that all of the selected metals were observed in marine organisms with a predomination of Cu and Zn. The metal exposure levels exhibited obvious variations between species with the decreasing order of crab>shellfish>shrimp>fish. The higher metals enrichment seen in shellfish and crab species primarily attributed to their living habits and the higher sediment background values of trace metals. Endpoint bioaccumulation factor (BAF_fd) was used to characterize the bioaccumulation potentials of marine organisms to trace metals, of which Cu and Zn were the most accumulated elements. The exposure of trace metals in the cultured organisms was far lower than those in wild marine organisms, which is probably due to the effect of growth dilution. Comparisons with previous studies demonstrated that the concentration profiles of most trace metals declined over the last one to two decades, except Cu, that increased indistinctively.