Assessment of combined antiandrogenic effects of binary parabens mixtures in a yeast-based reporter assay

To date, toxicological studies of endocrine disrupting chemicals (EDCs) have typically focused on single chemical exposures and associated effects. However, exposure to EDCs mixtures in the environment is common. Antiandrogens represent a group of EDCs, which draw increasing attention due to their resultant demasculinization and sexual disruption of aquatic organisms. Although there are a number of in vivo and in vitro studies investigating the combined effects of antiandrogen mixtures, these studies are mainly on selected model compounds such as flutamide, procymidone, and vinclozolin. The aim of the present study is to investigate the combined antiandrogenic effects of parabens, which are widely used antiandrogens in industrial and domestic commodities. A yeast-based human androgen receptor (hAR) assay (YAS) was applied to assess the antiandrogenic activities of n-propylparaben (nPrP), iso-propylparaben (iPrP), methylparaben (MeP), and 4-n-pentylphenol (PeP), as well as the binary mixtures of nPrP with each of the other three antiandrogens. All of the four compounds could exhibit antiandrogenic activity via the hAR. A linear interaction model was applied to quantitatively analyze the interaction between nPrP and each of the other three antiandrogens. The isoboles method was modified to show the variation of combined effects as the concentrations of mixed antiandrogens were changed. Graphs were constructed to show isoeffective curves of three binary mixtures based on the fitted linear interaction model and to evaluate the interaction of the mixed antiandrogens (synergism or antagonism). The combined effect of equimolar combinations of the three mixtures was also considered with the nonlinear isoboles method. The main effect parameters and interaction effect parameters in the linear interaction models of the three mixtures were different from zero. The results showed that any two antiandrogens in their binary mixtures tended to exert equal antiandrogenic activity in the linear concentration ranges. The antiandrogenicity of the binary mixture and the concentration of nPrP were fitted to a sigmoidal model if the concentrations of the other antiandrogens (iPrP, MeP, and PeP) in the mixture were lower than the AR saturation concentrations. Some concave isoboles above the additivity line appeared in all the three mixtures. There were some synergistic effects of the binary mixture of nPrP and MeP at low concentrations in the linear concentration ranges. Interesting, when the antiandrogens concentrations approached the saturation, the interaction between chemicals were antagonistic for all the three mixtures tested. When the toxicity of the three mixtures was assessed using nonlinear isoboles, only antagonism was observed for equimolar combinations of nPrP and iPrP as the concentrations were increased from the no-observed-effect-concentration (NOEC) to effective concentration of 80 %. In addition, the interactions were changed from synergistic to antagonistic as effective concentrations were increased in the equimolar combinations of nPrP and MeP, as well as nPrP and PeP. The combined effects of three binary antiandrogens mixtures in the linear ranges were successfully evaluated by curve fitting and isoboles. The combined effects of specific binary mixtures varied depending on the concentrations of the chemicals in the mixtures. At low concentrations in the linear concentration ranges, there was synergistic interaction existing in the binary mixture of nPrP and MeP. The interaction tended to be antagonistic as the antiandrogens approached saturation concentrations in mixtures of nPrP with each of the other three antiandrogens. The synergistic interaction was also found in the equimolar combinations of nPrP and MeP, as well as nPrP and PeP, at low concentrations with another method of nonlinear isoboles. The mixture activities of binary antiandrogens had a tendency towards antagonism at high concentrations and synergism at low concentrations.     

臭氧-曝气生物滤池深度处理印染制革园区废水

针对浙江省某印染制革园区污水处理厂二级生化出水,开展了处理规模36~120 t/d的臭氧-曝气生物滤池中试研究,对臭氧预处理进行优化,考察了臭氧预处理优化后与不同填料BAF组合对污染物的去除情况。结果表明,当臭氧预处理条件为投加量25 mg/L,三点投加且投加比为6：3：1,臭氧接触时间为42 min时,处理效果较好且最经济;在此臭氧预处理条件下,臭氧-活性炭BAF的出水COD能稳定在50 mg/L,色度稳定在5度,满足《城镇污水厂污染物排放标准》（GB 18918-2002）中的一级B排放要求;臭氧-混合填料BAF的出水COD和色度也能基本达到一级B排放要求;而臭氧-陶粒BAF出水COD和色度都未能达到一级B排放要求。     

两种膜生物反应器处理养猪沼液的比较研究

养猪沼液有机物和氨氮浓度高,碳氮比低,生化处理难度大.本文对比研究了生物膜式膜生物反应器(biofilm membrane bioreactor,BF-MBR)和传统膜生物反应器(MBR)在进水化学需氧量(COD)和总氮(TN)比值分别为1.0±0.2和2.3±0.4条件下对养猪沼液的处理效果.结果表明,养猪沼液COD/TN为1.0±0.2时,两套反应器的出水水质都较差且波动较大.进水COD/TN比值提高到2.3±0.4后,两套系统的出水水质和运行稳定性均得到大幅度提高;BF-MBR对COD和氨氮的去除率分别为92.3%±2.4%和97.5%±4.1%,略优于MBR的91.9%±1.5%和91.2%±14.0%.与MBR相比,BF-MBR因生物膜的影响,对总氮和总磷去除率分别达36.7%±19.5%和54.0%±18.9%,显著高于MBR去除率19.2%±12.4%和29.0%±18.1%;BF-MBR系统比MBR减少了近40%的外加碱耗.BF-MBR比MBR有更好的污染物去除效果且消耗更少的外加碱剂,因此对处理沼液的适用性更好.     

基于情景分析的浙江沿海地区环境污染防治战略研究

运用情景分析方法研究了浙江沿海地区经济发展方式对环境产生的压力.首先以COD、氨氮、二氧化硫和氮氧化物这4种污染物的排放量为基准,筛选了某典型城市的18个重污染工业行业.其次以重污染工业行业为对象,设计了情景分析模型和辅助程序,以2008年为基准年,目标年2015年重污染工业行业4种污染物的排放量须在基准年基础上下降一定比例作为约束条件,分析在基准情景、产业结构调整情景、工业结构调整情景、清洁生产技术情景、综合情景、可持续发展6种情景下,目标年该市18个重污染行业4种主要污染物的排放量.目的是明确人均GDP已突破70 000元的沿海经济发达城市如何转变发展方式,使经济发展的同时,污染物排放量有所减少,以期为优化工业行业发展结构提供决策参考.基于情景分析结论,提出了进一步发展建议,包括经济适度增长(GDP增长7%左右),加大力度调整产业结构,控制重污染行业发展速度,加强重污染行业的结构调整,加强源头控制,加大力度推进清洁生产技术,大幅削减污染物产生量,同时加强治污设施运营监管,提高污染物去除效率.通过上述措施在目标年可控制重污染行业的COD、氨氮、二氧化硫和氮氧化物分别在基准年基础上下降10%、10%、5%和15%.     

2种填料BAF深度处理印染废水沿程污染物变化规律研究

针对某印染工业园区污水处理厂二级生化处理出水,采用处理规模为15 t·d-1的中试试验,研究了活性炭填料和悬浮填料曝气生物滤池沿程的污染物浓度变化,探讨了用低价、轻质悬浮填料替代活性炭的可行性.结果表明,在进水COD和色度分别为50.2 mg·L-1和58倍时,活性炭和悬浮填料曝气生物滤池最终出水COD和色度分别为35.0 mg·L-1、18倍和44.3mg·L-1和26倍,均可达到城镇污水厂污染物排放标准(GB 18918-2002)中的一级A排放标准要求,但是悬浮填料曝气生物滤池达标所需沿程的高度为2 400 mm,高于活性炭曝气生物滤池的1 800 mm.悬浮填料曝气生物滤池对色度、总氮、氨氮的去除效果及沿程变化趋势与活性炭曝气生物滤池相仿,但COD去除效果不佳,主要是与其生物量少有关.因此,用悬浮填料替代活性炭在该污水厂是可行的,但仍需要对填料大小和材质进行优选,增大生物量,必要时可考虑使用活性炭和悬浮填料的组合工艺减少造价成本.     

嘉兴市规模化养猪场沼液水质调查研究

以嘉兴市10家大型规模化养猪场为对象,开展了沼液水质调查,测试了COD、氮、磷和外源化学品(抗生素、重金属)的污染水平.结果表明,不同猪场之间水质差异很大,且同一猪场的沼液水质随时间波动很大.其中春季检测组的猪场沼液浓度普遍较高,COD、氨氮、TN和TP的浓度分别高于2000、1000、1000和60 mg·L-1的猪场有7家,秋季和冬季检测组的沼液浓度稍低,夏季检测组最低.沼液碳氮比失衡严重,其中秋季检测组最低,仅为0.8~4.3.4类(四环素类、磺胺类、大环内酯类、喹诺酮类)共10种抗生素和6种重金属(铜、锌、铅、铬、镍和镉)在10家猪场沼液中均有检出.重金属以铜、锌为主,平均值分别为1.88 mg·L-1和7.63 mg·L-1.抗生素以四环素类(四环素、土霉素、金霉素)为主.10种抗生素总浓度的最低值为10.1μg·L-1,最高值为1090μg·L-1,远高于欧盟的水环境抗生素阈值(10 ng·L-1).猪场沼液不仅氮磷脱除难,而且重金属和抗生素污染严重,亟待开发低成本高效无害化处理与资源化利用技术.     

工业园区环境污染第三方治理发展实践新趋势

环境污染第三方治理是一种可有效发挥政府、排污主体、市场力量等多方优势,提高环境污染治理效率并降低综合成本的重要模式。工业园区在有限的物理空间内入驻了大量的企业,资源能源消耗和污染产生集中,是环境污染第三方治理重要的实践载体。本文对2016年以来生态环境部（原环境保护部）、国家发展改革委等部门针对工业园区推进环境污染第三方治理的实践创新进行综述,从试点项目、典型模式、成效与挑战等方面对园区已开展的第三方治理实践进行分析,认为第三方治理在推进园区绿色发展中优点突出,已开展大量多样化实践,具有广阔的进一步发展前景,但同时仍需突破机制模式、管理制度等瓶颈。在国家针对工业园区污染防治突出系统优化、资源能源双控、排放提标、精细化管理等趋势下,全面深化环境污染第三方治理的机遇和挑战并存,主要面临着硬件设施和管理体系不平衡不完善两大问题。最后,研究提出了创新第三方环境综合服务和针对“双碳”目标深入推进工业园区第三方污染治理的两方面政策建议,以期为工业园区深化环境污染第三方治理实践创新和促进园区绿色发展提供决策参考。     

曝气生物滤池工艺脱氮性能及反硝化细菌群落结构特征研究

比较了两组不同填料组合的前置反硝化曝气生物滤池(biological aeration filter,BAF)脱氮工艺:陶粒-沸石BAF工艺(C-Z BAF)和沸石-陶粒BAF工艺(Z-C BAF),在不同C/N条件下的脱氮效果及滤料表面的反硝化细菌群落结构特征.结果表明,Z-C BAF对TN的平均去除效率高于C-Z BAF,且在低C/N条件下Z-C BAF的优势更加明显,当C/N为3.3时Z-C BAF的TN平均去除率比C-Z BAF高出20%.测定2种组合在不同C/N条件下的反硝化细菌群落结构发现,随着C/N的降低,2种组合反硝化细菌的物种丰度和多样性显著下降.低C/N条件下,Z-C BAF整个好氧滤池的nosZ基因优势T-RFs相对丰度>20%,而C-Z BAF好氧滤池顶端样品不能有效扩增到nosZ基因,可推断Z-C BAF的同步硝化反硝化功能优于C-Z BAF.在低C/N条件下Z-C BAF的脱氮效率明显高于C-Z BAF,因此Z-C BAF在低C/N且低浓度的有机废水处理方面更有潜力.     

AnMBR/A/OMBR处理焦化废水的运行条件优化与运行效果

采用厌氧膜生物反应器/缺氧/好氧膜生物反应器（AnMBR/A/OMBR）处理某焦化厂实际焦化废水,通过优化运行参数使该工艺达到最佳运行工况,并考察最佳运行条件下系统长期稳定运行的处理效果。结果表明,向进水添加磷源能满足微生物的生长需求并促进脱氮过程,同时控制OMBR内的pH能较好地保证系统出水NH3-N的去除率和稳定性。AnMBR/A/OMBR系统的最佳运行条件为：总HRT为61.3 h,进水TP浓度为（2.3±0.3）mg·L-1,OMBR内pH为（7.5±0.2）、DO为4~6 mg·L-1,回流比为2∶1。当系统进水COD、TOC、NH3-N和TN的平均浓度分别为（1790±17） mg·L-1、（447.3±9.1） mg·L-1、（107.3±5.2） mg·L-1和（221.9±5.6） mg·L-1时,在最优条件下系统出水的平均浓度分别为（254±76） mg·L-1、（53.8±3.2） mg·L-1、（3.9±1.1） mg·L-1和（70.0±8.8） mg·L-1,去除率分别为（85.7±0.9）%、（88.0±0.7）%、（96.4±1.1）%和（68.5±3.7）%。进水中Ⅰ、Ⅱ区芳香族蛋白质类似物和Ⅳ区溶解性微生物副产物的总和所占比例达88.5%,系统出水中Ⅱ区芳香族蛋白质类似物占40%,含量最高。     

瓜环对污水厂二级处理出水中有机污染物的混凝性能

采用扫描电子显微镜和傅里叶红外光谱技术考察了瓜环的物化性能,以及溶液pH和瓜环投加量对其混凝效果的影响。结果表明,盐酸对瓜环的助溶效果最佳,混凝后絮体颗粒呈密实的团状。红外光谱中无新吸收峰出现,说明瓜环与污水中有机物的混凝去除以物理作用为主,无化学键的形成。当投药量大于400 mg/L时,瓜环对初始有机物浓度为6.0 mg/L和9.2 mg/L的污水厂二级处理出水的TOC去除率分别在20%和25%以上。与明矾和聚合氯化铝等传统混凝剂相比,瓜环的混凝性能明显优于传统混凝剂且受pH值的影响较小,作为新型水处理材料具有一定的研究价值和应用前景。