On-site and off-site atmospheric PBDEs in an electronic dismantling workshop in south China: gas-particle partitioning and human exposure assessment

Gas samples and total suspended particle during work and off work time were investigated on-site and off-site electronic waste dismantling workshop (I- and O-EWDW), then compared with plastic recycling workshop (PRW) and waste incineration plant (WIP). TSP concentrations and total PBDE were 0.36-2.21 mg/m³ and 27-2975 ng/m³ at different workshops, respectively. BDE-47, -99, and -209 were major ∑PBDE congeners at I-EWDW and WIP, while BDE-209 was only dominant congener in PRW and control sites during work time and all sites during off work time. The gas-particle partitioning result was well correlated with the subcooled liquid vapor pressure for all samples, except for WIP and I-EDWD, at park during work time, and residential area during off work time. The predicted urban curve fitted well with measured φ values at O-DEWD during work time, whereas it was slightly overestimated or underestimated for others. Exposure assessment revealed the highest exposure site was I-EDWD.     

过渡金属浸渍改性ACF去除H2S研究

为探讨活性炭纤维(ACF)去除恶臭气体H2S的性能,采用过渡金属浸渍改性ACF吸附H2S,揭示出改性ACF前后吸附H2S的性能差异及浸渍剂的浓度和种类对ACF吸附性能的影响。结果表明,通过过渡金属改性后的ACF吸附性能有显著提高,对H2S吸附是物理吸附和化学吸附共同作用的结果,改性后的ACF硫容量大小依次为：5％硝酸铜...     

植物床人工湿地处理养殖废水研究

为研究风车草和美人蕉植物床人工湿地处理养殖废水效果,建立了4级波式流人工湿地。结果表明,SS、COD、NH+4-N、TN和TP的去除率分别达到了76％、77％、78％、77％和72％,美人蕉生物量和氮磷含量都要高于风车草,植物组织中氮磷分布为叶＞根＞茎。重金属在植物中的含量为Zn＞Pb＞Cu＞Ni＞Cr,其中Zn、Pb...     

污泥用量对生活垃圾堆肥氮素转化与损失的影响

为了探讨生活垃圾堆肥的氮素损失问题,对生活垃圾（A组）、污泥和生活垃圾混合B组（w/w=1∶6）、C组（w/w=1∶4）组等3组物料进行高温好氧堆肥,研究污泥用量对生活垃圾堆肥化过程中温度、pH值、各氮素转化与损失的影响。结果表明：投加污泥会影响生活垃圾的通风性能,减慢物料的升温速率,延长堆肥周期。污泥用量对生活垃圾堆...     

洞庭湖湿地生态系统管理面临的威胁及应对策略初探

生态系统管理可以实现自然资源的多目标管理。洞庭湖湿地生态系统优越,区域内社会经济发达,但面临保护与发展的双重压力。其中,开展洞庭湖区湿地生态系统管理面临众多威胁,包括自然灾害频发、资源利用不当、工农业污染突出、自然保护能力不足以及季节性缺水等新老问题交织在一起,共同导致了洞庭湖湿地生态系统功能降低,包括生物多样性降低、调蓄能力减弱、洪渍涝灾害加剧、地下水位升高、垸老田低等现象日益突出,而且这种人类不合理活动的后效放大驱动将长期存在,危及到了湖区水产养殖的自然增殖以及自然资源基础的安全性,成为湖区社会经济发展的严重制约因素。为此,建议在遵循生态系统方法的前提下,洞庭湖地区应该加强管理体制机制创新实践,加快湿地保护的立法与执法进程,通过编制洞庭湖区中长期发展总体规划,促进各种利益相关方参与和共管洞庭湖湿地退田还湖等生态恢复工程的巩固、湿地资源合理利用、湿地产业的开发以及湖区湿地生态与环境建设,最终实现湖区生态美好、民生改善的“人地和谐     

Photocatalytic inactivation of Escherichia coli by natural sphalerite suspension: effect of spectrum, wavelength and intensity of visible light

The photocatalytic disinfection of Escherichia coli K-12 is investigated by the natural sphalerite (NS) under different spectra, wavelengths and intensities of visible light (VL) emitted by light-emitting-diode lamp (LED). The spectrum effect of VL on disinfection efficiency is studied by using white LED, fluorescent tube (FT) and xenon lamp (XE), which indicates that the “discreted peak spectrum” of FT is more effective to inactivate bacteria than “continuous spectrum” of LED and XE. Besides, the photocatalytic disinfection of bacteria is compared under different single spectrum (blue, green, yellow and red color) LEDs. The results show that the most effective wavelength ranges of VL for photocatalytic disinfection with the NS are 440-490 and 570-620 nm. Furthermore, a positive relationship is obtained between the disinfection efficiency and the VL intensity. The experiment shows that NS can completely inactivate 10⁷ cfu mL⁻¹E. coli K-12 within 8 h irradiation by white LED with the intensity of 200 mW cm⁻² at pH 8. Moreover, the destruction process of the cell wall and the cell membrane are directly observed by TEM. Finally, no bacterial colony can be detected within a 96 h regrowth test of inactivated bacteria, which reveals that the VL-photocatalytic disinfection leads to an irreversible damage to the bacterial cells.     

MAP法处理高浓度氨氮废水技术研究进展

MAP法(磷酸铵镁沉淀法)是去除废水中高浓度氨氮的一种有效技术。本文叙述了MAP法去除废水中氨氮的反应机理,分析pH值、物质摩尔比,反应时间等影响因素。该方法具有去除率高、反应速度快、受外界环境影响小等特点,同时还实现了对氮的有效回收,具有较好的应用前景。     

低分子量壳聚糖Nd~(3+)配合物的合成及抑菌性研究

通过将高分子量壳聚糖经双氧水氧化降解制得低分子量壳聚糖,再与Nd3+配位制得低分子量壳聚糖Nd3+配合物,通过IR,UV,TG-TDA和GPC分析对L-CTS的分子量及L-CTS-Nd的结构进行了表征,考察了对金黄色葡萄球菌和大肠杆菌的抑菌性能。结果表明,低分子量壳聚糖与Nd3+形成了稳定的配合物,对金黄色葡萄球菌和大肠杆菌均有良好的抑菌效果。     

“热洗+助溶剂萃取”技术处理含油污泥的应用

为解决大量堆存的含油污泥可能造成的环境隐患问题,新疆油田公司针对含油污泥无害化、资源化技术进行探索研究。采用"热洗+助溶剂萃取"工艺技术处理,使含油污泥中矿物油含量从处理前的8%～30%降低至处理后的0.3%以下,满足GB 4284—84《农用污泥中污染物控制标准》的要求,有效回收了石油资源,减少环境污染,装置运行能耗成本为62.55元/t,具有运行费用低、操作简便的特点,为油田规模化、产业化处理含油污泥提供借鉴。     

再生水中NO_3~--N、NO_2~--N、NH_4~+-N在粉土介质中迁移转化的研究

通过土柱实验模拟再生水在粉土层下渗过程中NO3--N、NO2--N、NH4+-N的迁移转化规律。结果表明,实验温度为23.2～25.9℃时,土柱内发生反硝化反应,NO3--N的去除率为9.74%～39.16%,反应符合一级反应动力学方程,衰减系数为0.0968～0.5531m-1;实验温度低于19℃时,土柱内反硝化反应消失,说明低温是制约再生水在土柱内发生反硝化作用的主要因素。