Degradation of organic pollutants in Mediterranean forest soils amended with sewage sludge

The degradation of two groups of organic pollutants in three different Mediterranean forest soils amended with sewage sludge was studied for nine months. The sewage sludge produced by a domestic water treatment plant was applied to soils developed from limestone, marl and sandstone, showing contrasting alkalinity and texture. The compounds analysed were: linear alkylbenzene sulphonates (LAS) with a 10–13 carbon alkylic chain, and nonylphenolic compounds, including nonylphenol (NP) and nonylphenol ethoxylates with one and two ethoxy groups (NP1EO + NP2EO). These compounds were studied because they frequently exceed the limits proposed for sludge application to land in Europe. After nine months, LAS decomposition was 86–96%, and NP + NP1EO + NP2EO decomposition was 61–84%, which can be considered high. Temporal trends in LAS and NP + NP1EO + NP2EO decomposition were similar, and the concentrations of both types of compounds were highly correlated. The decomposition rates were higher in the period of 6–9 months (summer period) than in the period 0–6 months (winter + spring period) for total LAS and NP + NP1EO + NP2EO. Differences in decay rates with regard to soil type were not significant. The average values of decay rates found are similar to those observed in agricultural soils.     

几种常用总氮总磷有机分析方法的结果比较

论述了几种常用总氮、总磷分析方法的原理和特点,运用准确度和精密度检验,比较了它们各自对不同有机氮、磷物质和有机污染水体的分析结果。实验结论表明,加和法和还原法不能满足一般方法要求;氧化法具有较高的准确度和精密度,实用性强,建议推广。      

Performance evaluation of a completely stirred anaerobic reactor treating pig manure at a low range of mesophilic conditions

Many Chinese biogas plants run in the lower range of mesophilic conditions. This study evaluated the performance of a completely stirred anaerobic reactor treating pig manure at different temperatures (20, 28 and 38 °C). The start-up phase of the reactor at 20 °C was very long and extremely poor performance was observed with increasing organic loading rate (OLR). At an OLR of 4.3 g ODM L^?1 d^?1, methane production at 28 °C was comparable (3% less) with that at 38 °C, but the risk of acidification was high at 28 °C. At low OLR (1.3 g ODM L^?1 d^?1), the biogas process appeared stable at 28 °C and gave same methane yields as compared to the reactor operating at 38 °C. The estimated sludge yield at 28 °C was 0.065 g VSS g^?1 COD_removed, which was higher than that at 38 °C (0.016 g VSS g^?1 COD_removed).     

Performance and stability of an anaerobic fixed bed reactor subjected to progressive increasing concentrations of influent organic matter and organic shock loads

Data on the performance of a horizontal-flow anaerobic immobilized biomass (HAIB) reactor subjected to step increases of organic loading rates (OLR) and to organic shock loads (OSL) are presented and discussed. The tubular reactor (100 cm long and 5 cm diameter) with a useful volume of 1995 mL was filled with polyurethane foam cubic matrices holding immobilized biomass and fed with synthetic wastewater. The reactor was operated at the controlled temperature of 30+/-1 degrees C and hydraulic retention time of 7 h. After about 15 days, the HAIB reactor attained operating stability. Thereafter, it was subjected to step increases of the applied OLR that ranged from 6.8 to 18.8 kg COD/m(3)d. After steady state had been achieved at each step, OSL corresponding to approximately three times the operating OLR were applied for 7 h. No disturbance was observed due to the step increase in OLR. An increase in effluent chemical oxygen demand (COD) and volatile fatty acids (VFA) concentrations and a decrease in the percentage of methane in the biogas were observed due to OSL applications. However, stability of the monitoring parameters was always restored approximately 17 h after the application of OSL for all conditions tested.     

水中有机污染物电化学清除的研究进展

介绍利用直接电解发、间接电解和电化学吸附等方法去除水中有机污染物的研究现状,并指出今后的工作方面。     

商业步行街的环境空气污染

阐述了商业步行街的环境空气污染对人群健康造成危害的原因,通过在广州市北京路和下九路,以及周围交通街道模拟行人行走方式的采样和分析,得出在广州市商业步行街及其周围交通街道空气中,除了含有有毒有害的挥发性有机物、PM10、和CO等,芳香烃类等化合物的浓度水平也普遍较高,特别是苯和甲苯。另外,周围交通街道上的机动车尾气排放对商业步行街的环境空气质量也有影响。     

有机污染物水排放标准推荐值的确定

针对我国《污水综合排放标准》GB8978-1996存在的问题,根据以毒理学实验数据为基础的水环境目标值和排放目标值,参考美国EPA推荐的水质量标准、GB8978-1996《污水综合排放标准》、GB3838-2002《地面水质量标准》和实测的环境数据,提出重点控制有机污染物水排放标准推荐值。     

有机热载体炉大气污染物的适用排放标准

介绍了有机热载体炉的分类和工作原理，并对有机热载体炉与蒸气锅炉的基本特性及其烟尘测试的主要特点进行了比较，提出有机热载体炉大气污染物的适用排放标准应按照GB13271-2001《锅炉大气污染物排放标准》执行。     

广州市河涌底泥中主要污染物的垂直分布特征

分析了广州市3条河涌底泥中有机质、石油烃、Cd、Cr、Cu、Ni、Pb、Zn等主要污染物的垂直分布特征。结果表明:曾边涌、南村涌、会江涌底泥中有机质平均值分别为43.15mg/kg、10.80 mg/kg、34.81 mg/kg,石油烃含量平均值分别为:1644 mg/kg,2427 mg/kg,6763 mg/kg。有机质和石油烃垂直变化特征相似,曾边涌呈现表层底泥含量低而底层高的特征,南村涌呈现随深度增加而降低的趋势,会江涌呈现先降低后上升的趋势,3条河涌底泥中不同重金属垂直变化规律不一样;河涌底泥中污染物所呈现的垂直分布规律并不总是上层污染物浓度高而下层低的正常沉积特征。因此,在考虑通过清淤改善河流水质时,应考虑河流污染的历史,并调查沉积物中污染物垂直分布的实际情况。     

颗粒物有机源示踪物的筛选与应用综述

大气颗粒物中的不少有机组分具有较强的源指向性,是识别颗粒物来源并评估各污染源对城市大气环境影响的重要工具之一.前人因此针对不同污染源颗粒物有机组成进行了广泛研究,并筛选出大量具有源指纹意义的有机示踪物.本文对前人的相关工作进行了简要整理,重点关注了生物质燃烧、餐饮源、化石燃料燃烧和交通源排放颗粒物有机组成特征,总结了这...