放射性核素在海水、底质及海洋生物间的转移--Ⅰ.核素进入海水后的初始状态

作者在建立的人工小生境中,研究了具有生态学意义的~(137)Cs、~(134)Cs、~(65)Zn、~(60)Co、~(59)Fe、~(54)Mn等核素在海水、底质及海洋生物间的转移规律.本文是该项研究的第一部分,研究悬浮物、底质对核素的富集和吸附,考察了核素进入海水后的初始状态.     

抚顺市空气可吸入颗粒物特征的研究

于2002年1～7月份在抚顺市区四个点位采集了环境空气中的可吸入颗粒物样品，经分析后获得了可吸入颗粒物组分的时间分布和空间分布特征，即采暖期PM10样品中有机碳（OC）、元素碳（EC）的绝对含量和相对含量均高于非采暖期，工业区PM10样品中的Fe、Zn、Pb的绝对含量和相对含量均明显高于其它点位，反映了其工业区的特点。     

染料生物吸附影响因素与解吸条件研究

用筛选出的一株丝状真菌(GX2)对活性、酸性、碱性和直接染料进行吸附及解吸的试验结果表明，该菌株对活性、酸性和直接染料有较高的吸附率，但碱性染料难被吸附；在多种有机溶剂中，丙酮是较好的解吸剂，碱性介质有利于染料的解吸；对菌体进行破碎及在解吸过程中加以搅拌有利于解吸过程的进行。     

宁波台地倾斜在皎口地震活动中的前兆反应特征

通过对宁波台地倾斜近几年来观测资料的分析，发现其在皎口几组地震事件前有不同程度的异常反应。在分量图上，震前出现了短临期前兆异常反应特征，并且有异常时间越长，幅度越大，地震震级就越高的特点。此外还对异常出现的成因作了探讨     

高活性萘降解细菌Hydrogenophaga Palleronii LHJ38的研究

为了研究微生物对多环芳烃的降解和转化规律,以萘作为研究对象,从餐厨油烟污染土壤中筛选到一株萘降解活性较高的细菌菌株,经菌种鉴定,定名为帕氏氢噬胞菌(H ydrogenophaga Palleronii)LH J38。测定了该菌的生长曲线和萘降解曲线,建立了菌株对萘的降解活性的定量测定方法,并研究了其最适生长条件。结果表明,在28℃、初始pH6.6、碳氮摩尔比为4的最适培养条件下,LH J38对初始质量浓度为2 000m g/L的萘在96h内的降解率可达98%以上;处于对数生长期的LH J38对萘的降解活性可达47.3nm o l/(m g.m in)。     

Reaction kinetics of waste sulfuric acid using H2O2 catalytic oxidation

The process of recovering waste sulfuric acids using H₂O₂ catalytic oxidation is studied in this paper. Activated carbon was used as catalyst. Main operating parameters, such as temperature, feed rate of H₂O₂, and catalyst dosage, have effects on the removal of impurities from waste sulfuric acids. The reaction kinetics of H₂O₂ catalytic oxidation on impurities are discussed. At a temperature of 90°C, H₂O₂ feeding rate of 50 g (kg waste acid)^?1 per hour, and catalyst dosage of 0.2 wt% (waste acid weight), the removal efficiencies of COD and chrominance were both more than 99%, the recovery ratio of sulfuric acid was more than 95%, and the utilization ratio of H₂O₂ was 88.57%.

Implications: Waste sulfuric acid is a big environmental problem in China. The amount of waste sulfuric acid is huge every year. Many small and medium-sized businesses produced lots of waste acids, but they don’t have an appropriate method to treat and recover them. H₂O₂ catalytic oxidation has been used to treat and recover waste sulfuric acid and activated carbon is the catalyst here. Main parameters, such as temperature, feed rate of H₂O₂, and catalyst dosage, have been investigated. The reaction kinetics are discussed. This method can be economical and feasible for most small and medium-sized businesses.     

Environmentally Friendly Polyurethane Composites: Preparation, Characterization and Mechanical Properties

The waterborne polyurethane (PU) prepolymer was prepared based on isophorone diisocyanate (IPDI), polyester polyol (N220), dimethylol propionic acid (DMPA) and hydroxyethyl methyl acrylate (HEMA). The modified waterborne polyurethane–acrylate (PUA) emulsions were obtained with different proportions of acrylate (butyl acrylate and methyl methacrylate) and initiating agent by in situ dispersion technique. The structures and thermal properties of prepared PU and PUA were analyzed and characterized with FT-IR, UV–Vis spectroscopy and DSC. The PUA hybrid samples had lower glass transition temperature of hard segment and higher decomposition temperatures than PU sample. Performances of the emulsion and film were studied by means of apparent viscidity, particle size and polydispersity, surface tension and mechanical properties. The results indicated that the particle sizes of the PUA dispersions were larger than those of the pure PU and the solvent resistance, mechanical properties of PUA films was improved compare with the unmodified polyurethane film. The film had the biggest hardness and the least water absorption when the BA/MMA mass ratio 5:5 modified PU. The obtained PUA have great potential application such as coatings, leather finishing, adhesives, sealants, plastic coatings and wood finishes.     

A comparison of antibiotics,antibiotic resistance genes,and bacterial community in broiler and layer manure following composting

Animal manure is an important source of antibiotics and antibiotic resistance genes (ARGs) in the environment. However, the difference of antibiotic residues and ARG profiles in layer and broiler manure as well as their compost remains unexplored. In this study, we investigated the profiles of twelve antibiotics, seventeen ARGs, and class 1 integrase gene (intI1) in layer and broiler manure, and the corresponding compost at large-scale. Compared with layer manure, broiler manure exhibited approximately six times more residual tetracyclines, especially chlortetracycline. The relative abundances of qnrS and ermA genes in broiler manure were significantly higher than those in layer manure. The concentration of tetracyclines not only had a significantly positive correlation with tetracycline resistance genes (tetA and tetC) but was also positively correlated with quinolone resistance (qepA, qnrB, and qnrS) and macrolide resistance (ermA and ermT). Most ARGs in manure were reduced after composting. However, the relative abundance of sulfonamide resistance gene sul1 increased up to 2.41% after composting, which was significantly higher than that of broiler (0.41%) and layer (0.62%) manure. The associated bacterial community was characterized by high-throughput 16S rRNA gene sequencing. The relative abundances of thermophilic bacteria had significant positive correlations with the abundance of sul1 in compost. The composting has a significant impact on the ARG-associated gut microbes in poultry manure. Variation partitioning analysis indicated that the change of bacterial community compositions and antibiotics contributed partially to the shift in ARG profiles. The results indicate that at industry-scale production broiler manure had more antibiotics and ARGs than layer manure did, and composting decreased most ARG abundances in poultry manure except for sulfonamide resistance genes.

     

Urban carbon emission intensity under emission trading system in a developing economy: evidence from 273 Chinese cities

Environmental Science and Pollution Research - The international community has generally recognized the key role of developing countries’ cities in reducing carbon emissions, an elemental way...     

The catalytic performance of Cu46Zr47-xAl7Yx amorphous ribbons in the degradation of AO II dye wastewater

Environmental Science and Pollution Research - Metallic glasses (MGs) with unique disordered atomic stacking structures exhibit excellent catalytic performance in wastewater treatment. The...