高氯酸钾项目生产过程中的环境风险及防范措施

根据国家环保总局发布的"高污染、高环境风险"产品名录(2009年),无机盐产品高氯酸钾属于高环境风险的产品,其生产存在较大风险。高氯酸钾项目在生产过程中的环境风险主要来源于强酸、强碱、有毒有害、易燃易爆等原辅材料、产品,运输、贮存和使用过程产生的燃爆、泄漏、贮运风险以及工艺废气治理措施失效等环节。识别项目产生的环境风险主要包括爆炸风险、泄漏风险、危险化学品贮运风险及氯气直排风险,并从生产管理、生产工艺及贮运等方面提出相应的防范措施。     

Synthesis of Ni-doped anatase TiO2 single crystals loaded on wood-based activated carbon for enhanced photodegradation of triphenylmethane dyes

Environmental Science and Pollution Research - In this work, the Ni-doped anatase TiO2 single crystals loaded on activated carbon (Ni-T/AC) were synthesized by a sol–gel method. The chemical...     

液液提取-固相萃取-LC-MS/MS测定人体尿液中有机磷系阻燃剂及其二酯类代谢物

本研究基于液液提取和固相萃取技术建立了检测人体尿液中有机磷系阻燃剂(OPFRs)及其二酯类代谢产物(diesters)的前处理方法,采用液相色谱串联三重四极杆质谱(LC-MS/MS)进行定性定量分析.根据OPFRs与diesters理化性质的差异,尿液酶解后采用甲基叔丁基醚(MTBE)与二氯甲烷:正己烷(4∶1,V/V)混合液提取,有机相经Florisil固相萃取柱净化,乙酸乙酯洗脱后,测定OPFRs含量;水相过Strata-X-AW柱萃取,5%三乙胺/乙腈(V/V)洗脱后,测定diesters含量.在优化的实验条件下,OPFRs和diesters在相应浓度范围内呈良好线性关系,相关系数r介于0.9978—0.9997之间;尿液样品中OPFRs加标回收率平均值在72.4%—125%之间,RSD为0.62%—4.40%;6种diesters平均加标回收率为79.7%—126%,RSD介于2.20%—9.75%之间.本方法所需样品量少且能对OPFRs和diesters同时进行检测,方法的平行性好、结果可靠.使用该方法对15例尿液样品中的OPFRs与diesters含量进行分析发现,尿液中OPFRs检出率较低,7种OPFRs检出率均小于50%;6种diesters中仅双(丁氧乙基)磷酸酯(BBOEP)未在任何样品检出,其余5种diesters检出率介于33.3%—93.3%之间,其中磷酸二苯酯(DPHP)和双(1,3-二氯-2-丙基)磷酸酯(BDCIPP)检出率分别达93.3%和86.7%,是检出最高的两种化合物.     

珠三角地区大气PM2.5中重金属污染水平及健康风险评价

采集了珠三角地区2014—2015年冬、夏两季的环境空气PM_(2.5)样品,利用电感耦合等离体质谱仪(ICP-MS)测定了样品中的重金属含量,并采用US EPA环境健康风险评价模型,对其健康风险进行了评估.结果表明:环境空气中重金属元素Pb、Cu、Zn、Cd、As、Ni、Cr的浓度分别为11.1~183.0、48.5~406.0、110~1218、0.2~14.4、3.5~77.0、0.38~18.90、2.89~93.20 ng·m-3,浓度大小顺序为:ZnCuPbAsCrNiCd;除As外,其余重金属浓度均表现为冬季高于夏季.元素As经皮肤黏滞及口腔摄入的非致癌风险值均在安全范围内,但经呼吸途径暴露存在非致癌风险;Cu、Zn、Cd、Cr经3种途径暴露不存在非致癌风险;元素Pb、As、Cd、Cr经皮肤黏滞及口腔摄入的致癌风险均值尚在安全值范围内,但经呼吸暴露存在致癌风险;元素Ni经3种途径暴露不存在致癌风险.对于综合危害指数(HI),除As外,其他金属元素的HI值均低于安全值,各金属元素的HI值大小顺序为:AsCdNiCr.研究表明,在珠三角区域环境空气PM_(2.5)中,元素As、Cr存在一定的健康风险.     

硫酸亚铁结合电化学絮凝处理中水氨氮与总磷的研究

文章分别采用硫酸亚铁絮凝法、电化学法以及硫酸亚铁结合电化学法对中水中低浓度氨氮和总磷的处理效果进行了对比。研究了硫酸亚铁投加量、pH、通电时间和电压对氨氮和总磷去除率的影响。结果表明:采用硫酸亚铁絮凝法,硫酸亚铁投加量为6%,pH为6～7,氨氮去除率为95.45%,总磷去除率92.5%;采用电化学絮凝法,通电时间40 min,通电电压20 V,pH为6～7,中水中氨氮去除率为72.73%,总磷去除率为92.5%;硫酸亚铁结合电化学处理中水,通电电压为20 V,通电时间30 min,硫酸亚铁投加量7%时,中水中氨氮去除率99.09%,总磷去除率92.5%。因为氨直接在阳极失去3个电子被氧化成N2,阳极电解时生成的金属阳离子或其水合物与水中的磷酸盐形成沉淀。而硫酸亚铁通过空轨道吸附铵根中氮的孤对电子后被水解生成的含有Fe3+的羟基络合物絮凝沉淀,Fe2+和Fe3+也都可以与PO43-生成难溶性磷酸盐。     

Dual-functional sites for synergistic adsorption of Cr(VI) and Sb(V) by polyaniline-TiO2 hydrate: Adsorption behaviors,sites and mechanisms

• PANI/Ti(OH)_n^(4–n)+ exhibited excellent adsorption capacity and reusability. • Adsorption sites of Cr(VI) were hydroxyl, amino/imino group and benzene rings. • Sb(V) was adsorbed mainly through hydrogen bonds and Ti-O-Sb. • The formation of Cr-O-Sb in dual system demonstrated the synergistic adsorption. • PANI/TiO₂ was a potential widely-applied adsorbent and worth further exploring. Removal of chromium (Cr) and antimony (Sb) from aquatic environments is crucial due to their bioaccumulation, high mobility and strong toxicity. In this work, a composite adsorbent consisting of Ti(OH)_n^(4–n)+ and polyaniline (PANI) was designed and successfully synthesized by a simple and eco-friendly method for the uptake of Cr(VI) and Sb(V). The synthetic PANI/TiO₂ composites exhibited excellent adsorption capacities for Cr(VI) and Sb(V) (394.43 mg/g for Cr(VI) and 48.54 mg/g for Sb(V)), wide pH applicability and remarkable reusability. The adsorption of Cr(VI) oxyanions mainly involved electrostatic attraction, hydrogen bonding and anion-π interactions. Based on X-ray photoelectron spectroscopy and FT-IR analysis, the adsorption sites were shown to be hydroxyl groups, amino/imino groups and benzene rings. Sb(V) was adsorbed mainly through hydrogen bonds and surface complexation to form Ti-O-Sb complexes. The formation of Cr-O-Sb in the dual system demonstrated the synergistic adsorption of Cr(VI) and Sb(V). More importantly, because of the different adsorption sites, the adsorption of Cr(VI) and Sb(V) occurred independently and was enhanced to some extent in the dual system. The results suggested that PANI/TiO₂ is a promising prospect for practical wastewater treatment in the removal of Cr(VI) and Sb(V) from wastewater owing to its availability, wide applicability and great reusability.