高温干发酵对互花米草产气和结构的影响

互花米草的疯长已带来严重的环境问题,厌氧发酵提供了一种资源化的解决途径.通过渗滤床高温、干式发酵互花米草,考察其产气特性;并通过元素分析、X-ray和FT-IR分析,考察干发酵及预处理对互花米草物化性质的影响.结果表明:60 d高温干发酵互花米草,累计产气量为280.9 mL/g VS(0℃);总TS与VS去除率分别为...     

Fe/AC催化湿式过氧化氢氧化处理焦化废水

采用浸渍法制备了负载型Fe/AC催化剂,通过比表面积、热重等方法对其进行了表征,并以焦化废水中的主要污染物苯酚、喹啉、氨氮为研究对象进行催化湿式过氧化氢氧化处理（CWPO）,考察了Fe/AC催化剂的制备条件和CW-PO处理工艺条件对Fe/AC催化剂的稳定性和催化活性的影响。结果表明：催化剂活性组分的负载量、焙烧温度、初...     

Fluorescence excitation-emission spectroscopy with regional integration analysis for assessment of compost maturity

Composting of animal manures is believed as an alternative way for directly recycling them in farms, and therefore assessment of compost maturity is crucial for achieving high quality compost. Fluorescence excitation-emission matrices (EEMs) combined with regional integration analysis is presented to assess compost maturity. The results showed that the EEM contours of water-extract organic matter (WEOM) from immature composts exhibited four peaks at excitation/emission (Ex/Em) of 220/340 nm, 280/340 nm, 220/410 nm, and 330/410 nm, whereas EEM contour of WEOM from mature composts had only two peaks at Ex/Em of 230/420 nm and 330/420 nm. Pearson correlation demonstrated that peaks intensity rather than their ratios had a significantly correlation with the common indices assessing compost maturity, whereas the normalized excitation-emission area volumes (Φ_i,ns) from regional integration analysis had a stronger correlation with the common indices assessing compost maturity than peaks intensity. It is concluded that the Φ_i,ns from regional integration analysis are more suitable to assess the maturity of compost than the intensities of peaks. Therefore, the fluorescence spectroscopy combined with regional integration analysis can be used as a valuable industrial and research tool for assessing compost maturity, given its high sensitivity and selectivity.     

Apolipophorin III and transmission electron microscopy as toxicity indicators for harmaline and tea saponin in Spodoptera exigua (Noctuidae: Lepidoptera)

Apolipophorin III, traditionally known for lipid transport in insects is fairly established as toxicity indicator against harmaline and tea saponin during this study. Apolipophorin III expressed in the hemolymph and midgut tissues of 3rd, 4th, 5th larval instars and pupae of Spodoptera exigua. Apolipophorin III presence was further confirmed by achieving its partial cDNA (Genbank accession no. FJ606822) of 448 bp. qRT PCR revealed that tea saponin resulted in significant reduction of gene expression in 3rd and 4th larval instars but increased in 5th instar as compared to control. Harmaline caused gradual increase of gene expression in 3rd, 4th and 5th instars after feeding on the treated diet. Fifth instar larvae synonymously resulted in the highest gene expressions against both the biochemicals. After the injection of harmaline and tea saponin abrupt increase in gene expression of 4th, 5th larval instar and pupae was observed as compared to control treatment. Transmission electron microscopy of midgut epithelium after being fed with harmaline and tea saponin depicted certain cytological changes. Harmaline treatment lead to cytoplasm vacuolization, mitochondrial disruption, spherocrystals with concentric layers, irregular nucleus and floating nuclei in cytoplasm. Tea saponin treatment resulted in denser cytoplasm, higher intracellular osmotic concentration and reduced complement of apical microvilli. Cells were found to have only a few mitochondria and glycogen deposits in comparison to control treatment.     

Comparison of initial hydrolysis of the three dimethyl phthalate esters (DMPEs) by a basidiomycetous yeast,Trichosporon DMI-5-1, from coastal sediment

Purpose  

Dimethyl phthalate esters (DMPEs) are a group of plasticizers commonly detected in the environment with potential adverse human health impact. The degradation of DMPEs by fungal systems has been studied to a limited extent, particularly by yeasts. In this study, a basidiomycetous yeast Trichosporon DMI-5-1 capable of degrading DMPEs was obtained and the degradation pathways were investigated.     

水体沉积物毒性鉴别与评价研究进展

综述了水体沉积物毒性鉴别与评价的主流方法以及研究进展,指出毒性测试和致毒因子鉴别方法是限制水体沉积物污染生态风险评价的关键因素,认为发展和应用以生物标记物和生物效应为导向,尤其是各种具有污染专一性指示作用的生物效应标志测试方法的建立和应用,并结合具有选择性的样品分级技术和先进的仪器进行定性定量分析,将是以生物效应为导向、以化学分析为基础的复杂水体沉积物毒性鉴别与评价的重要发展方向.     

用生命周期的方法评价铜炉渣作为铜选矿原料的环境影响

运用生命周期评价的方法,分别对铜炉渣和铜矿石回收铜的选矿过程的环境协调性进行了对比研究,得到了选矿生产过程中各工序的环境负荷数据。评价结果表明,铜炉渣的人类健康损害、生态系统损害和资源损害分别为0.20783、0.00764和0.01919,而铜矿石的分别是0.08165、0.0075和0.08857,铜炉渣生产铜的资源损害比铜矿石低,而人类健康损害和生态系统损害比铜矿石高,铜炉渣选矿生产过程每生产1 kg渣精矿的环境负荷约为铜矿石的1.32倍。随着国内铜精矿供应缺口的增大,从铜炉渣中回收铜资源将显著地提高资源利用率,有利于循环经济的发展。     

生物亲和亲水磁性填料在污水生物处理中的应用

采用添加生物亲和亲水物质、活性炭及磁粉并磁化的改性聚丙烯填料,进行挂膜和模拟污水生物降解试验.结果发现,普通聚丙烯填料改性后,水滴静态接触角降低22%,含水率提高3～5倍;改性聚丙烯填料比普通聚丙烯填料具有更快的挂膜速度和更高的COD降解率,并能承受更高的气液比以及气流和水流的冲击.改性聚丙烯填料的挂膜期从普通聚丙烯填料的7 d缩短为3 d;将初始COD为500 mg/L的模拟污水完全降解,改性聚丙烯填料需10.5 h,而普通聚丙烯填料则需22.5 h;在连续处理的操作方式下,当气液比为40:1时,改性聚丙烯填料的COD降解率达到最大,为99%,而普通聚丙烯填料则在气液比为30:1时,达到最大的COD降解率,为79%.     

海带对镉的吸附动力学与热力学研究

采用批量平衡法研究了海带对镉的吸附的动力学与热力学,并采用Lagrange假一级动力学方程、假二级动力学方程、Langmuir等温线方程、Freundlich等温线方程以及Dubimim-Radushkevich等温线方程对实验数据进行了拟合.结果表明,在4种温度下海带对镉的吸附率均随吸附反应时间增加而增大,在60 min时达到最大,此后基本保持不变,随着温度由20℃升高至50℃,其最大吸附率呈下降趋势,由90.2%降至77.5%;海带对镉的吸附动力学符合Lagrange假二级动力学方程;海带对镉的吸附热力学符合Langmuir等温线方程和Dubimim-Radushkevich等温线方程,表明吸附主要发生在海带表面的活性区位,属于单分子层吸附,其吸附平均活化自由能E为11.4 kJ/mol,表明该吸附过程为化学吸附,在4种温度下吉布斯自由能变化量△AG°均为负值,吸附焓变△H°也为负值,表明海带对镉的吸附为放热反应,能自发进行.