进水方式对序批式人工湿地处理效能的影响

序批式人工湿地具有较高的脱氮效能,研究考察了序批式人工湿地间歇和连续2种进水方式对其处理效能的影响。研究表明,进水方式对TN去除效能影响显著,对COD、NH4＋-N去除影响不显著。在水温18～25℃,负荷38 gCOD/（m2.d）条件下,采用＂进水10 min-反应12 h-排水10 min-排空闲置4 h＂的间歇进水方式时,可使进水COD、NH4＋-N和TN分别为306、65和73 mg/L的生活污水,出水分别为45、7和19 mg/L,去除率分别为85%、89%和74%,与＂进水反应12 h-排水10 min-排空闲置4 h＂的连续进水方式相比,COD和TN的去除率分别提高4%和32%。     

关于死海地区臭氧耗损现象(ODEs)的研究综述

自1997年在死海地区的大气边界层中观测到午间臭氧浓度迅速下降的现象后,研究学者们即对该地区的臭氧耗损现象(ozone depletion events,简称ODEs)展开了研究.而在此之前,大气边界层内的ODEs现象普遍被认为只会发生在极地地区的特殊大气现象.本文综述了关于死海地区ODEs研究的发展历史,主要展示了促...     

Arsenic species in electronic cigarettes: Determination and potential health risk

Human exposure to contaminants from electronic cigarettes(e-cigarettes) and the associated health effects are poorly understood.There has been no report on the speciation of arsenic in e-liquid(solution used for e-cigarettes) and aerosols.We report here determination of arsenic species in e-liquids and aerosols generated from vaping the e-liquid.Seventeen e-liquid samples of major brands,purchased from local and online stores in Canada and China,were analyzed for arsenic species using high-perfo...     

Removal of inorganic arsenic from water using metal organic frameworks

<正>It has been estimated that between 94 million and 220 million people around the world are at risk of consuming drinking water that contain arsenic concentrations higher than 10 μg/L( Podgorski and Berg, 2020),     

Optimization, equilibrium, adsorption behavior and role of surface functional groups on graphene oxide-based nanocomposite towards diclofenac drug

Aquatic contamination of diclofenac(DCF), an emergent non-steroidal anti-inflammatory drug(NSAIDs), can result in adverse effects to many ecosystems through biomagnification.Hence, introducing effective remediation techniques to sequester the pharmaceutical wastes is highly fundamental to prevent their accumulation in the environment. Generally,adsorption has been presented as a green and efficient approach. Herein, we report the characterization and application of the novel magnetic nanocomposi...     

污染土壤重金属稳定化复配固化剂研发与验证

文章以工业废渣、矿物材料和磷酸盐材料为基础材料,逐步开展单一重金属稳定化实验(实验Ⅰ)、复合重金属稳定化实验(实验Ⅱ)及污染土壤重金属稳定化验证实验(实验Ⅲ)。实验Ⅰ中,工业废渣稳定效果最佳,对重金属Pb、Zn、Cd的去除率均超过93%;工业废渣与重金属溶液反应后的上清液p H值升高明显,平均增幅5左右。实验Ⅱ中,复配固化剂可实现对重金属Pb、Zn、Cd的同时去除,Pb、Zn和Cd的去除率分别为88.29%～99.95%、40.73%～99.46%和14.80%～98.35%;复合重金属溶液与药剂反应后,除S13～S16组外,上清液pH值略升高;不同比例复配固化剂对复合溶液重金属的去除率有所差异,沉淀中矿物种类和衍射峰强度略有差异;Cd2+倾向于与PO43-形成沉淀,复配固化剂和重金属生成一系列在中性环境难溶或者微溶于水的沉淀;与实验Ⅰ产物特征相比,复配固化剂与复合重金属反应后无明显的羟基硝酸铅矿物相生成。实验Ⅲ中,1#固化剂对土壤的p H值改变较小,2#固化剂对土壤中重金属的固化效果优于1#固化剂;对所挑选的3种重金属的固化效率均高于85%的试块进行重金属形态分析,试块中重金属固化效...     

季铵化改性对风化煤腐殖酸水处理性能的影响

对风化煤腐殖酸(HA)进行季铵化改性得到季铵化腐殖酸(QHA),将HA与QHA用作水处理剂,对比两者的阻垢缓蚀性能。结果表明,QHA的阻垢率和缓蚀率均优于HA。QHA、HA投加量分别在20、30 mg/L时阻垢率达到最大值,分别为85.77%、73.50%。HA与QHA的缓蚀率均随投加量的增大而提高,投加量为40mg/L时,QHA的缓蚀率达82.10%,比HA高出22.51百分点。QHA热稳定性能更好,阻垢缓蚀的最佳pH为8～9。QHA具有良好的分散能力和灭藻能力,可在8h内实现高效灭藻。CaCO3垢样的扫描电镜、X射线衍射分析表明,加入QHA使垢体松散,呈碎状分布,晶格结构发生畸变,CaCO3晶面生长的有序度和完整度下降,从而表现出良好的阻垢性能。     

空气扰动对净化器去除香烟源颗粒物性能的影响

空气净化器可有效改善雾霾天气下室内空气质量,颗粒物去除效果与洁净空气量(CADR)是衡量其性能的主要参数。在典型室内环境下,以香烟源颗粒物为目标,开展空气扰动对净化器去除颗粒物效果和CADR的影响实验与评价分析。结果显示,在室内空气扰动下,净化器对粒径≥5μm的颗粒物去除率为75.6%,在无空气扰动情况下的去除率为46.6%。空气净化器对粒径0.3μm^5μm的颗粒物有较好的去除效果,而对于粒径10μm的较大颗粒物,空气扰动造成CADR增加。空气扰动在一定程度上提升了空气净化器的净化能力,同时在性能方面也存在影响。     

Deposition of artificial radionuclides from atmospheric Nuclear Weapon Tests estimated by soil inventories in French areas low-impacted by Chernobyl

Soil inventories of anthropogenic radionuclides were investigated in altitudinal transects in 2 French regions, Savoie and Montagne Noire. Rain was negligible in these 2 areas the days after the Chernobyl accident. Thus anthropogenic radionuclides are coming hypothetically only from Global Fallout following Atmospheric Nuclear Weapon Tests. This is confirmed by the isotopic signatures (²³⁸Pu/^239+240Pu; ¹³⁷Cs/^239+240Pu; and ²⁴¹Am/^239+240Pu) close to Global Fallout value. In Savoie, a peat core age-dated by ²¹⁰Pb_ex confirmed that the main part of deposition of anthropogenic radionuclides occurred during the late sixties and the early seventies. In agreement with previous studies, the anthropogenic radionuclide inventories are well correlated with the annual precipitations. However, this is the first time that a study investigates such a large panel of annual precipitation and therefore of anthropogenic radionuclide deposition. It seems that at high-altitude sites, deposition of artificial radionuclides was higher possibly due to orographic precipitations.     

Prediction of the PCDD/F and dl-PCB 2005-WHO-TEQ content based on the contribution of six congeners: Toward a new screening approach for fish samples?

Current European Union regulation regarding polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (dl-PCBs) in food and feed is based on Toxic Equivalent Quotient (TEQ) concept. For confirmatory purpose, the isotope-dilution method associated to a measurement by gas chromatography coupled with high resolution mass spectrometry is usually the method of choice for precisely measuring the 29 target congeners in three separated fractions. Time and cost related to these analyses are very significant. Various kinds of screening concepts can be considered. In the present study, we elaborated and validated a prediction model for the 2005 World Health Organization TEQ in fish, based on the measurement of 4 PCDD/F and 2 non-ortho dl-PCB congeners, potentially analyzable in a single extracted fraction by gas chromatography coupled with mass spectrometry. Large independent datasets have been used for model elaboration (n = 108) and validation (n = 363, n = 357 and n = 6).