丁二烯过氧化物的生成、危害及安全性研究

综述了国内外丁二烯过氧化物研究进展，主要包括丁二烯过氧化物的危害性、成因、危险评价和热稳定性，并对今后的研究方向进行了展望。     

珠江上游少数民族县域经济活动的累积环境效应研究--以贵州三都水族自治县为例

为了探索珠江上游少数民族区域经济活动的累积环境效应与生态安全，我们选择三都水族自治县作为定位研究基地．对建国以来区域内经济活动变迁进行历史、现状研究和综合评估，揭示历史时期发展政策、发展模式、重大经济活动等人为扰动因素在区域生态环境系统退化过程中的作用．评估少数民族经济活动的累积环境效应与生态安全。     

Operating condition influences on PCDD/Fs emissions from sinter pot tests with hot flue gas recycling

This study was designed to clarify the influence of operating conditions on the formation and emissions of polychlorinated-pdibenzodioxins and dibenzofurans (PCDD/Fs) from a sintering process with hot flue gas recycling. A pilot scale sinter pot with simulated flue gas recycling was developed, and four key operational parameters, including temperature, oxygen content of the simulated waste flue gas, the coke rate of the sintering mixture, and the quicklime quality, were selected for exploring PCDD/Fs formation. The results showed that the temperature of the recycled flue gas had a major affect on PCDD/Fs formation, and a high temperature could significantly increase their formation during sintering. A clear linear correlation between the temperature of recycling flue gas and PCDD/Fs emission (r = 0.93) was found. PCDD/Fs could be reduced to a certain extent by decreasing the level of oxygen in the recycled flue gas, while sintering quality was unchanged. The coke rate had no significant influence on the formation of PCDD/Fs, but the quality of quicklime used in the sintering mixture could affect not only the amount of PCDD/Fs emissions but also the sintering productivity. Compared with a benchmark sinter pot test, PCDD/Fs emissions markedly decreased with improvements to quicklime quality. However, the reduction in PCDD/Fs emissions realized by using high-quality quicklime was limited by the temperature of the inlet gas. The highest reduction achieved was 51% compared with conventional quicklime when the temperature of the inlet gas was 150°C.     

吐纳麝香长期暴露下蚯蚓体内金属硫蛋白和谷胱甘肽变化

吐纳麝香(AHTN)作为人工合成麝香中多环麝香的典型代表,具有挥发性、易生物富集等特性,由于其在环境中的浓度日益升高,呈现出一定的生物效应,可能对生态系统的稳态存在着潜在的威胁,为探讨上述课题,试验通过采用自然土壤法以赤子爱胜蚓(Eiseniafetida)作为试验动物,首次研究测定蚯蚓在AHTN的长期暴露条件下,其体内金属硫蛋白和谷胱甘肽含量的变化。试验结果得出低浓度的AHTN能够抑制机体内金属硫蛋白和谷胱甘肽的生成,使得金属硫蛋白和谷胱甘肽的含量显著减少,在一定浓度范围内的AHTN对机体无明显不利影响,而高浓度的AHTN能够诱导机体内金属硫蛋白和谷胱甘肽的生成,使得金属硫蛋白和谷胱甘肽的含量显著增多(P<0.05),从而对土壤环境存在着潜在的生态风险。     

Biological sulfate removal from acrylic fiber manufacturing wastewater using a two-stage UASB reactor

A two-stage UASB reactor was employed to remove sulfate from acrylic fiber manufacturing wastewater. Mesophilic operation (35±0.5℃) was performed with hydraulic retention time (HRT) varied between 28 and 40 hr. Mixed liquor suspended solids (MLSS) in the reactor was maintained about 8000 mg/L. The results indicated that sulfate removal was enhanced with increasing the ratio of COD/SO₄^2-. At low COD/SO₄^2-, the growth of the sulfate-reducing bacteria (SRB) was carbon-limited. The optimal sulfate removal efficiencies were 75% when the HRT was no less than 38 hr. Sulfidogenesis mainly happened in the sulfate-reducing stage, while methanogenesis in the methane-producing stage. Microbes in sulfate-reducing stage performed granulation better than that in methane-producing stage. Higher extracellular polymeric substances (EPS) content in sulfate-reducing stage helped to adhere and connect the flocculent sludge particles together. SRB accounted for about 31% both in sulfate-reducing stage and methane-producing stage at COD/SO₄^2- ratio of 0.5, while it dropped dramatically from 34% in sulfate-reducing stage to 10% in methane-producing stage corresponding to the COD/SO₄^2- ratio of 4.7. SRB and MPA were predominant in sulfate-reducing stage and methane-producing stage respectively.     

Air pollution characteristics and their relationship with emissions and meteorology in the Yangtze River Delta region during 2014–2016

With rapid economic growth and urbanization, the Yangtze River Delta(YRD) region in China has experienced serious air pollution challenges. In this study, we analyzed the air pollution characteristics and their relationship with emissions and meteorology in the YRD region during 2014–2016. In recent years, the concentrations of all air pollutants, except O_3,decreased. Spatially, the PM_(2.5), PM_(10), SO_2, and CO concentrations were higher in the northern YRD region, and NO_2 and O_3 were higher in the central YRD region. Based on the number of non-attainment days(i.e., days with air quality index greater than 100), PM_(2.5) was the largest contributor to air pollution in the YRD region, followed by O_3, PM_(10), and NO_2.However, particulate matter pollution has declined gradually, while O_3 pollution worsened.Meteorological conditions mainly influenced day-to-day variations in pollutant concentrations. PM_(2.5) concentration was inversely related to wind speed, while O_3 concentration was positively correlated with temperature and negatively correlated with relative humidity.The air quality improvement in recent years was mainly attributed to emission reductions.During 2014–2016, PM_(2.5), PM_(10), SO_2, NO_x, CO, NH_3, and volatile organic compound(VOC)emissions in the YRD region were reduced by 26.3%, 29.2%, 32.4%, 8.1%, 15.9%, 4.5%, and0.3%, respectively. Regional transport also contributed to the air pollution. During regional haze periods, pollutants from North China and East China aggravated the pollution in the YRD region. Our findings suggest that emission reduction and regional joint prevention and control helped to improve the air quality in the YRD region.     

从生物群落到生态系统综合保护：国家公园生态系统完整性保护的理论演变

自然保护事业已经进入人与自然和谐的综合保护阶段,突破传统生物群落保护的要素式思维,从生态特征、生态系统健康和自组织能力等视角系统实施生态系统完整性保护,已基本成为共识。中国经历了长期部门化割裂管理,在国家公园体制建设过程中开始由分散走向统一,要求将山水林田湖草作为生命共同体进行生态系统完整性保护。基于集合种群等空间生态学理论,提出国家公园生态系统完整性不仅意味着内部自然空间的完整,更需着眼国家生态安全的大局和自然保护地体系的战略布局。国家公园只有成为生态地理区的节点并辐射周边区域,有效平衡行政区域之间以及人与自然之间的关系,才能真正实现完整生态系统的长效保护。目前,国内既有研究在指导全域布局和平衡人地关系方面仍考虑不足,试点过程中还存在管理型技术方法欠缺、空间边界受限于行政边界、未能从全局着眼构建以国家公园为核心的生态系统完整性网络、未充分考虑差异化的人地关系等问题。未来需要着眼大局,有效平衡国家公园及其周边区域的关系、不同行政区域之间的关系、国家公园人与自然的关系,从而实现生态系统完整性的长效保护。     

Simultaneous quantification of fifty-one odor-causing compounds in drinking water using gas chromatography-triple quadrupole tandem mass spectrometry

A wide range of compounds with various structural features can cause taste and odor(TO)problems in drinking water. It would be desirable to determine all of these compounds using a simple analytical method. In this paper, a sensitive method combining liquid–liquid extraction(LLE) with gas chromatography-triple quadrupole tandem mass spectrometry(GC–MS/MS)was established to simultaneously analyze 51 odor-causing compounds in drinking water,including organic sulfides, aldehydes, benzenes, phenols, ethers, esters, ketones, nitrogenous heterocyclic compounds, 2-methylisoborneol and geosmin. Three deuterated analogs of target analytes, dimethyl disulfide-d6, benzaldehyde-d6 and o-cresol-3,4,5,6-d4,were used to correct the variations in recovery, and five isotope-labeled internal standards(4-chlorotoluene-d4, 1, 4-dichlorobenzene-d4, naphthalene-d8, acenaphthene-d10, phenanthrene-d10 respectively) were used prior to analysis to correct the variations arising from instrument fluctuations and injection errors. The calibration curves of the target compounds showed good linearity(R2 0.99, level = 7),and method detection limits(MDLs) below 1/10 of the odor threshold concentrations were achieved for most of the odorants(0.10–20.55 ng/L). The average recoveries of most of the analytes in tap water samples were between 70% and 120%, and the method was reproducible(RSD 20%, n = 7). Additionally, concentrations of odor-causing compounds in water samples collected from three drinking water treatment plants(DWTPs) were analyzed by this method.According to the results, dimethyl trisulfide, dimethyl disulfide and indole were considered to be the key odorants responsible for the swampy/septic odor. 2-Methylisoborneol and geosmin were detected as the main odor-causing compounds for musty/earthy odor in DWTP B.     

One-step synthesis of Cu(II) metal–organic gel as recyclable material for rapid, efficient and size selective cationic dyes adsorption

Efficient removal of non-biodegradable and hazardous dyes from wastewater remains a hot research topic. Herein, a rationally designed a Cu(Ⅱ)-based metal–organic gel(Cu-MOG) with a nanoporous 3 D network structure prepared via a simple one-step mixing method was successfully employed for the removal of cationic dyes. The Cu-MOG exhibited high efficiency, with an adsorption capacity of up to 650.32 mg/g, and rapid adsorption efficiency, with the ability to adsorb 80% of Neutral Red within 1 min. The high adsorption efficiency was attributed to its large specific surface area, which enabled it to massively bind cationic dyes through electrostatic interaction, and a nanoporous structure that promoted intra-pore diffusion. Remarkably, the Cu-MOG displayed size-selective adsorption, based on adsorption studies concerning dyes of different sizes as calculated by density functional theory. Additionally, the adsorption performance of the Cu-MOG still maintained removal efficiency of 100% after three regeneration cycles. These results suggested that the Cu-MOG could be expected to be a promising and competitive candidate to conveniently process wastewater.