Risk assessment of xenoestrogens in a typical domestic sewage-holding lake in China

Release of domestic sewage leads to accumulation of xenoestrogens in holding waters, especially in closed or semi-enclosed waters such as lakes. In the study, the occurrence, distribution, estrogenic activity and risk of eight xenoestreogens were evaluated in Lake Donghu, China. Nonylphenol (NP), octylphenol (OP), and bisphenol A (BPA) were identified as the main xenoestrogens ranging from tens of ng L⁻¹ (in the surface water) or ng g⁻¹ dw (in the suspended particles and sediment) to tens of μg L⁻¹ or μg g⁻¹ dw. The sum of 17β-estradiol equivalents (∑EEQs) ranged from 0.32 to 45.02 ng L⁻¹ in the surface water, 0.53 to 71.86 ng g⁻¹ dw in the suspended particles, and 0.09 to 24.73 ng g⁻¹ dw in the sediment. Diethylstilbestrol (DES) was determined as the main contributor to ∑EEQs followed by NP. The risk assessment showed a higher risk in the surface water than in the suspended particles and sediment in such domestic sewage-holding lake.     

Residues of persistent organic pollutants in frequently-consumed vegetables and assessment of human health risk based on consumption of vegetables in Huizhou,South China

Concentrations of 16 polycyclic aromatic hydrocarbons (PAHs), 16 phthalate esters (PAEs), eight organochlorine pesticides (OCPs) and seven polychlorinated biphenyls (PCBs) in 17 frequently-consumed varieties of vegetables collected from 48 sites in Huizhou were measured. Concentrations of PAHs and PAEs of leafy vegetables were higher than those of gourd and fruit vegetables but it was the opposite for OCPs and PCBs. A questionnaire of 450 local residents on vegetable consumption showed that the total vegetable ingested rates of females and males were 278.80 g person⁻¹ d⁻¹ and 282.92 g person⁻¹ d⁻¹, respectively. The weight-specific daily intakes of pollutants by females were higher than those by males because of differences in body weight. Twenty-seven pollutants were used to assess the potential risk to human health by calculating target hazard quotient (THQ) values. Results showed that the risk to females was higher than for males. OCPs were the major contributors to the risk for both females and males. The main risks were from consumption of eggplant, Chinese lettuce and luffa and were significantly related to the contents of di-nonyl phthalate, β-hexachlorocyclohexane, γ-hexachlorocyclohexane, p,p-dichlorodiphenyltrichloroethane and p,p-dichlorodiphenyl dichloroethane in vegetables. Although the THQ values induced by individual pollutants were relatively low, the total THQ values induced by 27 pollutants were above 1 in some administrative regions of Huizhou, which might give cause for concern.     

Factors influencing on the bioaccessibility of polybrominated diphenyl ethers in size-specific dust from air conditioner filters

Size-specific concentrations and bioaccessibility of polybrominated diphenyl ethers (PBDEs) in dust from air conditioner filters were measured, and the factors influencing the PBDE bioaccessibility were determined. Generally, the PBDE concentrations increased with decreasing dust particle size, and BDE209 (deca-BDE) was generally the predominant congener. The bioaccessibility ranged from 20.3% to 50.8% for tri- to hepta-BDEs, and from 5.1% to 13.9% for BDE209 in dust fractions of varied particle size. The bioaccessibility of most PBDE congeners decreased with increasing dust particle size. The way of being of PBDE (adsorbed to dust surface or incorporated into polymers) in dust significantly influenced the bioaccessibility. There was a significant negative correlation between the tri- to hepta-BDE bioaccessibility and organic matter (OM) contents in dust. Furthermore, tri- to hepta-BDE bioaccessibility increased with increasing polarity of OMs, while with decreasing aromaticity of OMs. The tri- to hepta-BDE bioaccessibility significantly positively correlated with the surface areas and pore volumes of dust. Using multiple linear regression analysis, it was found that the OM contents and pore volumes of dust were the most important factors to influence the tri- to hepta-BDE bioaccessibility and they could be used to estimate the bioaccessibility of tri- to hepta-BDEs according to the following equation: bioaccessibility (%) = 45.05 − 0.49 × OM% + 1.79 × pore volume. However, BDE209 bioaccessibility did not correlate to any of these factors.     

有机污染胁迫对人工湿地中浮萍抗氧化系统的影响

湿地植物在处理高负荷有机废水时会受到不同程度的氧化胁迫。本研究基于对浮萍的有机污染胁迫模拟系统,通过对浮萍脂质过氧化和抗氧化防御系统的监测与分析,研究了浮萍对有机污染胁迫的耐受能力及胁迫去除后浮萍的恢复规律。结果表明,浮萍对有机污染胁迫具有较高的耐受性,在胁迫去除后,具有一定的恢复能力。在COD小于400mg/L时,浮萍并未受到氧化胁迫;当COD达到800 mg/L时,浮萍体内ROS含量上升,细胞膜脂过氧化加剧,但抗氧化酶活性升高,抗氧化物质含量增加,浮萍可保持生长,胁迫去除后,抗氧化防御系统可恢复到对照水平;当COD过高（≥1 000mg/L）,ROS急剧上升,抗氧化防御系统遭受破坏,造成不可逆伤害,胁迫去除后不能恢复正常生长。     

废LCD面板有机材料水热资源化产乙酸

LCD面板主要由附着偏光片及液晶等有机材料的玻璃面板构成。有机材料的去除及资源化利用是废LCD面板处理的第一步。在水热条件下对废LCD面板进行了降解产酸研究。研究考察了反应温度、反应时间、氧化剂用量、水用量及pH值等对水热产乙酸产率及选择性的影响。通过正交实验确定了水热产乙酸的最佳操作条件：反应温度325℃,反应时间5min,氧化剂（30％H2O2）0．6mL,用水量2mL,近中性环境（pH6-6．5去离子水）。此条件下,乙酸产率及选择性分别为68．83％及70．56％。结果表明,以废LCD面板有机材料为原料,采用水热技术进行产乙酸反应,可实现其资源化再利用。     

改良型AO法组合工艺中有机物的三维荧光分析

采用三维荧光(EEM)光谱技术,对上海竹园第二污水处理厂改良型AO法组合工艺运行过程中的各种溶解性有机物(DOM)进行分析,并对比研究传统好氧活性污泥法曝气池出水和A/O脱氮工艺硝化池出水DOM的EEM光谱的迁移变化特性.结果表明,各种DOM中主要的荧光物质有类蛋白质(荧光峰A和B)及类腐殖质(荧光峰C),经改良型AO法组合工艺处理后,荧光峰的强度降低了14％～60％,同时类蛋白质和腐殖质的结构也发生了变化;腐殖酸溯源表明DOM中的腐殖酸以微生物代谢产生的带有荧光基团的腐殖酸类为主.     

光催化氧化降解垃圾渗滤液中溶解性有机物

研究了UV-TiO2光催化氧化降解垃圾渗滤液过程中溶解性有机物(DOM)的变化特征。结果表明:在适宜条件下,UV-TiO2光催化氧化降解垃圾渗滤液的色度、COD和DOC的去除率分别可达97%、72%和60%;紫外光谱分析说明渗滤液DOM中包括多种含有共轭双键、羰基的大分子有机物及多环芳香类化合物,不同光催化处理液中DOM具有基本一致的结构单元和官能团;红外光谱分析说明渗滤液DOM中含有大量包括羟基、羧基、氨基和苯环的芳香族化合物,在光催化处理液中这几种官能团都能被有效降解;GC/MS分析结果表明,渗滤液DOM中含有72种有机污染物,醇类、羧酸和酮类分别为25、14和12种;在光催化72 h处理液中,有机物减少为44种;酯类和醇类较多,分别为12种和16种;酮类8种,羧酸没有检出。     

小型好氧堆肥设备处理有机垃圾

针对我国生活垃圾的特点,提出了厨余等有机生活垃圾单独收集,在产生源头进行好氧堆肥处理。研制了好氧堆肥设备,由加热装置、通风装置、冷凝水收集和回灌装置,以及与该生物堆肥设备配套的生物过滤除臭装置、自控系统和数据采集软件几部分构成。自控系统由氧气、温度、湿度三路传感器以及2个控制器构成,并与加热装置、通风装置连接,能满足物料加热、供氧和散热的要求。本研究通过为期30 d的试运行实验表明,物料快速升温并稳定保持在高温阶段(50～60℃),物料中的氧气浓度保持在14%～16%范围内。在堆肥实验结束时,物料的含水率降至36.4%,有机质含量降至49%,另外,通过好氧速率指标也可判定物料达到腐熟。     

高速公路路面沉积物的污染特性

对湖南省长潭西高速公路不同采样点的路面沉积物进行取样分析,并检测了样品的颗粒级配、COD、重金属(Cu、Zn、Pb和Cd)和有机质。结果表明,路面沉积物主要以粒径<0.15 mm的颗粒为主;较小颗粒物中的COD含量高于较大颗粒中的COD含量;粒径在0.15 mm以下的颗粒物所含重金属Cu、Zn、Pb和Cd的浓度普遍高于所选的土壤标准值,降雨一旦形成径流将会产生严重的污染危害;沉积物中的有机质含量对重金属的吸附有一定的影响,有机质含量越高,沉积物中重金属含量相对也高。     

PAFC对水体中持久性有机污染物PFOA的混凝效果

针对含全氟辛酸(PFOA)的工业废水及应对PFOA的污染突发事件,采用PAFC及其复配粘土矿物凹凸棒和沸石进行混凝实验,并对几个影响因素进行了考察。结果表明,在PAFC的最佳投加量10 mg/L时,PFOA和浊度的去除率分别达到70.25%和99.42%,PAFC混凝处理PFOA的效果优于PAC;pH值对PAFC去除PFOA有一定的影响,当pH大于6时有利于PFOA的去除;PFOA和浊度的去除率随原始浊度的增加而增加;活性炭、盐酸改性凹凸棒、盐酸改性沸石、CT-MAB改性的沸石复配PAFC均可提高PFOA的去除率;改性处理后的沸石应用于PFOA的处理中,有望降低处理成本。