Physiological and molecular responses of the earthworm <Emphasis Type="Italic">Eisenia fetida</Emphasis> to polychlorinated biphenyl contamination in soil

Polychlorinated biphenyls (PCBs) are a class of man-made organic compounds ubiquitously present in the biosphere. In this study, we evaluated the toxic effects of different concentrations of PCBs in two natural soils (i.e. red soil and fluvo-aquic soil) on the earthworm Eisenia fetida. The parameters investigated included anti-oxidative response, genotoxic potential, weight variation and biochemical responses of the earthworm exposed to two different types of soils spiked with PCBs after 7 or 14 days of exposure. Earthworms had significantly lower weights in both soils after PCB exposure. PCBs significantly increased catalase (CAT), superoxide dismutase (SOD), and guaiacol peroxidase (POD) activity in earthworms exposed to either soil type for 7 or 14 days and decreased the malondialdehyde (MDA) content in earthworms exposed to red soil for 14 days. Of the enzymes examined, SOD activity was the most sensitive to PCB stress. In addition, PCB exposure triggered dose-dependent coelomocyte DNA damage, even at the lowest concentration tested. This response was relatively stable between different soils. Three-way analysis of variance (ANOVA) showed that the weight variation, anti-oxidant enzyme activities, and MDA contents were significantly correlated with exposure concentration or exposure duration (P < 0.01). Furthermore, weight variation, CAT activity, and SOD activity were significantly affected by soil type (P < 0.01). Therefore, the soil type and exposure time influence the toxic effects of PCBs, and these factors should be considered when selecting responsive biomarkers.     

石化企业浮顶罐大呼吸损耗核算方法分析

石化企业储罐无组织排放挥发性有机物(VOCs)带来严重的环境问题和油品损耗问题,以浮顶罐的大呼吸损耗为代表。在概述浮顶罐大呼吸损耗机理的基础上,以北京某石化企业的甲苯内浮顶罐为基准案例,对国内外4种核算公式进行了对比分析,考察了影响浮顶罐大呼吸损耗的因素,并提出有效的减耗措施。结果表明:采用我国推荐的公式进行核算更符合我国实际,需建立和完善以我国有机液体理化参数和储罐构造为基准的核算方法和软件;影响浮顶罐大呼吸损耗的主要因素包括油品性质、周转量、罐体直径、罐壁黏附系数等,其中罐壁黏附系数为关键影响因素。     

SGA对垃圾焚烧飞灰中重金属的固化性能研究简

根据EPA 1311、HJ/T 299-2007、HJ/T 300-2007和HJ 557-2009等国内外不同标准,研究了深圳某垃圾焚烧发电厂垃圾焚烧飞灰的浸出毒性,探讨了六硫代胍基甲酸（sixthio guanidine acid,SGA）、二甲基二硫代氨基甲酸盐（sodium dimethyl dithio carbamate,SDD）和Ca（OH）₂浓度对垃圾焚烧飞灰中重金属的固定性能的影响。研究结果表明,随着浸提液pH的降低,该厂焚烧飞灰中大部分金属元素的浸出量增大,焚烧飞灰浸出液中的Cd、Ni、Pb和Zn浓度分别超过国家危险废物鉴别标准（GB5085.3-2007）规定值的4.75倍、1.47倍、6.72倍和2.20倍,属于危险废弃物,必须进行稳定化处理。当固化剂SGA加入量为0.1 mol/kg时,稳定化后的重金属浸出浓度已经低于危险废物鉴别标准,且对Cd、Cr、Cu和Pb的固化性能优于SDD和Ca（OH）₂;当固化剂SGA、SDD和Ca（OH）₂加入量为0.5 mol/kg时,稳定化后的焚烧飞灰重金属浸出浓度均低于国家危险废物鉴别标准（GB 5085.3-2007）中的规定值。与SDD和Ca（OH）₂相比,SGA对垃圾焚烧飞灰中重金属的固化处理更具有优势。     

高氨废水短程硝化特性简

采用SBR装置,针对高氨废水的特点,在高氨条件下,以高氨低氧为转化手段,实现高氨废水短程硝化过程中亚硝化菌的驯化与积累。控制温度为28~31℃,曝气量为15~60 L/h,pH控制在7.8~8.2的条件下连续运行78 d。实验结果表明,运行11 d后实现了短程硝化,从11 d至78 d属于系统氨氮负荷提高期。在运行过程中,氨氮污泥负荷从开始的0.023 kg/（kg·d）逐步上升为0.3 kg/（kg·d）,最高时达到0.34 kg/（kg·d）,此时氨氮去除率仍维持90%以上。为观察驯化后短程硝化菌的形态,取驯化好的污泥进行电镜扫描,结果表明,污泥中的细菌形态主要以球状菌为主。     

An effective utilization of the slag from acid leaching of coal-waste: Preparation of water glass with a low-temperature co-melting reaction

This paper presents an effective utilization of slag from acid leaching of coal-waste with a novel approach, namely low-temperature co-melting method, for preparation of sodium silicate (Na₂O·nSiO₂) using slag from acid leaching of coal-waste as feedstock. It is very interesting that the co-melting reaction temperature of the mixture of Na₂CO₃ and the feedstock (50?100 μm) was as low as 850 °C, which was significantly lower than the temperature used in traditional sodium silicate production (1400 °C). The optimum SiO₂/Na₂O ratio was identified as 7:3 according to the results of thermogravimetry–differential scanning calorimetry (TGA-DSC), ICP-AES, and X-ray diffraction (XRD) analyses. In this condition, the main product was sodium disilicate (Na₂O·2SiO₂), with water solubility of 85.0%. More importantly, the impurities such as aluminum in the feedstock, which had adverse effect on subsequent treatment, were concentrated almost completely in the filter residue as insoluble sodium alumunosilicates, i.e., Na(Si₂Al)O₆·H₂O. The lower co-melting temperature of this process demonstrates a significant energy-saving opportunity and thus a promising approach for highly effective utilization of coal-waste.

Implications:Recently, alumina extraction from coal-waste has been extensively investigated and industrial applied in China. However, the slag-containing silica generated from the acid leaching process of coal-waste led to a secondary pollution, which hindered large-scale production. The proposed low-temperature co-melting method for preparation of sodium silicate (Na₂O·nSiO₂) using slag from acid leaching of coal-waste as feedstock indicated that it is an efficient approach for the recovery of silica from the acid-leached slag of coal-waste with minimal environmental impact.     

Habitat use by giant panda in relation to man-made forest in Wanglang Nature Reserve of China

To evaluate the effectiveness of human restoration in species conservation, in this study, we undertook a field survey of giant panda (Ailuropoda melanoleuca) habitat and man-made forest habitat in Wanglang Nature Reserve of China. Our results revealed that giant panda did not use the man-made forest in this area so far, and that there were significant differences between the giant panda habitat and the man-made forest habitat. Compared with giant panda habitat, the man-made forest habitat was characterized by lower shrub coverage, thinner trees and lower bamboo density. To improve the effectiveness of human restoration, the habitat requirement of giant panda should be fully consider in the whole process of habitat restoration.     

石油炼制行业新旧污染物排放标准的差异

分别介绍了旧标准GB 8978—1996《污水综合排放标准》、GB 16297—1996《大气污染物综合排放标准》和新标准GB 31570—2015《石油炼制工业污染物排放标准》的核心内容。从适用范围、排放限值和污染控制因子3个方面分析了石油炼制行业新旧污染物排放标准的差异。     

Absorption of NO and NO2 in Caprolactam Tetrabutyl Ammonium Halide Ionic Liquids

ABSTRACT

To explore environmentally benign solvents for the absorption of NO and NO₂, a series of caprolactam tetrabutyl ammonium halide ionic liquids were synthesized. The solubility of NO and NO₂ was measured at temperatures ranging from 298.2 to 363.2 K and atmospheric pressure, and the following trend in the solubility of NO and NO₂ in ionic liquids with various halide anions was observed, respectively: F > Br > Cl and Br > Cl > F. Moreover, as the temperature increased from 308.15 to 363.15 K and the mole ratio of caprolactam increased from 2:1 to 6:1, the solubility of NO increased. Alternatively, the solubility of NO₂ decreased as the temperature increased from 298.15 to 363.15 K, and the mole ratio of caprolactam increased from 2:1 to 6:1. The absorption and desorption of NO and NO₂ was practically reversible in the ionic liquids, which was characterized by nuclear magnetic resonance. The method, which is at least partially reversible, offers interesting possibilities for the removal of NO and NO₂.

IMPLICATIONS Basic ionic liquids with amino groups were synthesized and used to capture CO₂, SO₂, and H₂S, and to promote hydrogenation of CO₂. In this paper, the authors used caprolactam tetrabutyl ammonium halide ionic liquid (IL) as absorbing medium in which NO_x could be absorbed. NO_x desorbed from the absorbent could be efficiently reduced by right catalysts at high temperature. The absorbed NO and NO₂ gas could be desorbed at higher temperature, allowing the ionic liquids to be reused several times without loss of capability. It was believed that caprolactam tetrabutyl ammonium bromide (CPL-TBAB) ILs may be useful for NO_x removal reagent for pollution control.     

无锡市酸雨变化特征及气象条件影响研究

基于无锡市2008~2011年酸雨观测资料,利用功率谱分析、后向轨迹和聚类分析方法,研究了无锡市酸雨的变化特征,分析了气象因素对酸雨的影响,探讨了1 500 m高度的气团移动路径特征。结果表明：2008~2011年,无锡市酸雨pH值呈现逐年递增趋势,而且酸雨逐月pH值、逐月弱酸雨和强酸雨频率分别存在不同的周期性变化;酸雨酸性随降水量增加表现为先增强后减弱,但夏季降水与酸雨pH值的相关性并不显著;春季相对湿度与酸雨pH值呈现显著负相关,夏季气温则与酸雨pH值呈显著正相关;各季节1 500 m高度的轨迹存在一定差异,春冬季无锡市受内陆气团影响为主,夏秋季西太平洋水汽输送作用明显。总体而言,江浙赣和西太平洋是无锡酸雨前体物的主要来源地     

The distribution pattern of different patch types and heterogeneity of the light and temperature: Larix chinensis Beissn in Qinling Mountains (China)

Based on a field investigation in the sample of an old growth subalpine coniferous forests in Qinling Mountains (China), we recognized the gap-forming processes in Larix chinensis forest for four representative patches (gap phases (G), building phases (B), mature phases (M) and degenerate phases (D)). The distribution pattern of four different patches and heterogeneity of the light and temperature were analyzed. The percentages of four different patch types (G, B, M and D) were 32.3%, 24.5%, 23.5% and 19.7%, respectively. The light and temperature had significant change among four patch types. From 6 to 20 o’clock, gap patch types changed more significantly than other three phases. The light and temperature regimes in mature patch type had a relatively mild change. Such micro-environmental heterogeneity among four different patches can lead to species niche partitioning, and some deterministic factors are benefit to the coexistence of various species with different characteristics within forest community.