前置反硝化曝气生物滤池的挂膜启动研究

为了解前置反硝化曝气生物滤池(BAF)的启动规律,构建了小试规模的前置反硝化BAF,采用快速排泥、逐步增大水力负荷的策略考察了其启动过程中的污染物去除情况及启动特性。结果表明,在好氧柱水力负荷为2.04 m3/(m2·h),厌氧柱水力负荷为4.08 m3/(m2·h),回流比为100%,气水比为5.6∶1的情况下,前置反硝化BAF的启动需要49 d。启动过程中好氧池中硝化细菌的成熟是启动的关键。厌氧池中的反硝化细菌的成熟标志着启动的完成。启动完成后,前置反硝化BAF的出水COD、NH3-N及NO-3-N分别稳定在50、15和5 mg/L以下,满足国家一级A排放标准。     

计算毒理学在内分泌干扰物筛选上的应用和展望

内分泌干扰物通过干扰内分泌系统导致多种疾病,如生殖疾病、肥胖症甚至癌症。然而,面对环境中大量潜在的内分泌干扰物,传统的体外、体内评估方法由于成本高、耗时长等问题,难以实现内分泌干扰物的高通量筛查。计算毒理学逐渐发展成为被美国环保局(Environmental Protection Agency,EPA)、经济合作与发展组织(Organization for Economic Co-operation and Development,OECD)等机构所推荐的内分泌干扰物筛选与预测方法。本文综述了计算毒理学在内分泌干扰物筛选上的进展,主要包括分子对接和分子动力学模拟的应用,并对有害结局路径(adverse outcome pathway,AOP)的方法进行介绍和展望。     

青萍(Lemna minor L.)对氮磷的吸收特征

以西部地区优势浮萍品种青萍为实验对象,研究了青萍对不同浓度硝态氮和磷酸盐的吸收特征。结果表明,硝态氮浓度在1～10 mg/L范围内,青萍对硝态氮有较好的吸收效果,M-M方程可以较好地描述硝态氮浓度与青萍对硝态氮的吸收速率之间的关系,通过M-M方程拟合得到青萍对硝态氮的最大吸收速率为0.1167 mg/(g FW.h),亲和力常数为6.9274。磷酸盐浓度在0.1～1.0 mg/L范围内,青萍对磷酸盐也有较好的吸收效果,二次多项式回归可以较好地描述青萍吸收速率与磷酸盐浓度的关系,回归方程得到青萍对磷酸盐的最大吸收速率为0.0193 mg/(g FW.h),对应磷酸盐浓度为0.6 mg/L。     

Dioxin-like activity in sediments from Tai Lake, China determined by use of the H4IIE-luc bioassay and quantification of individual AhR agonists

Deterioration of the general ecosystem and specifically quality of the water in Tai Lake (Ch: Taihu), the third largest freshwater in China, is of great concern. However, knowledge on status and trends of dioxin-like compounds in Tai Lake was limited. This study investigated AhR-mediated potency and quantified potential aryl hydrocarbon receptor (AhR) agonists in sediments from four regions (Meiliang Bay, Zhushan Lake, Lake Center, Corner of Zhushan Lake, and Meiliang Bay) of Tai Lake by use of the in vitro H4IIE-luc, cell-based, transactivation, reporter gene assay, and instrumental analysis. Concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (Bio-TEQs) in sediments ranged from less than the limit of detection to 114.5 pg/g, dry weight, which indicated that organic extracts of sediments exhibited significant AhR-mediated potencies. Results of the potency balance analysis demonstrated that acid-labile, dioxin-like compounds represented a greater proportion of concentrations of Bio-TEQs in sediments from Tai Lake. Concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents calculated as the sum of the product of concentrations of individual congeners and their respective relative potencies (Chem-TEQs) based on polycyclic aromatic hydrocarbons and/or polychlorinated biphenyls represented no more than 10 % of the total concentrations of Bio-TEQs.     

镍基催化剂对污泥微波热解制生物气效能的影响

为实现污水污泥减量化、无害化及资源化的目标,在微波热解污水污泥基础上,进行了镍基催化剂对制取生物气效能影响的研究。采用元素分析对污泥元素进行检测,气/质联用分析(GC-MS)和气相色谱(GC)对热解生物气的组成和含量进行测定。实验结果表明,镍基催化剂的添加对微波热解污水污泥制取生物气有较大促进作用。5%添加量与800℃热解终温条件下具有最佳催化效果:生物气中H2、CO产量最大,H2产量由29 g/kg增加到35.8 g/kg,提升23.4%,CO产量由302.7 g/kg增加到383.3 g/kg,提升26.6%;同时催化剂还能提高热能利用效率,降低热解终温,即5%添加量在700℃热解终温时可达到空白800℃时的产气效果;镍基催化剂主要在500~600℃时发挥催化作用,加快了H2和CO的释放。微波热解污泥制取的生物气具有产量大、富含H2与CO等优点,可推动污水污泥的资源化进程。     

Bacterial toxicity comparison between nano- and micro-scaled oxide particles

Toxicity of nano-scaled aluminum, silicon, titanium and zinc oxides to bacteria (Bacillus subtilis, Escherichia coli and Pseudomonas fluorescens) was examined and compared to that of their respective bulk (micro-scaled) counterparts. All nanoparticles but titanium oxide showed higher toxicity (at 20 mg/L) than their bulk counterparts. Toxicity of released metal ions was differentiated from that of the oxide particles. ZnO was the most toxic among the three nanoparticles, causing 100% mortality to the three tested bacteria. Al₂O₃ nanoparticles had a mortality rate of 57% to B. subtilis, 36% to E. coli, and 70% to P. fuorescens. SiO₂ nanoparticles killed 40% of B. subtilis, 58% of E. coli, and 70% of P. fluorescens. TEM images showed attachment of nanoparticles to the bacteria, suggesting that the toxicity was affected by bacterial attachment. Bacterial responses to nanoparticles were different from their bulk counterparts; hence nanoparticle toxicity mechanisms need to be studied thoroughly.     

连云港公众对核电和火电风险感知的比较分析

研究造成不同人群对核电和火电风险感知差异的关键因素,并分析不同人群对这2种风险支付意愿(WTP)的差别.采用公众问卷调研法及多元统计法分析公众对核电和火电的风险感知.结果表明,年龄为30～39岁的人群以及教育程度为大专和研究生学历的人群对核电和火电的风险感知差别度具有显著差异性,同时也发现政府在人们对比核电和火电风险感知程度时扮演重要角色,即对政府信任度高的人对核电的风险感知度相对较低.风险支付意愿分析表明,不同分类人群对核电和火电风险的WTP值总体趋势一致,即女性高于男性,低龄组和高龄组高于中龄组,无业者和家庭主妇高于有固定职业者,受中等教育者高于受低等和高等教育者,30 000～50 000元年薪者高于其他年薪段人,外地游客高于移居者和本土居民.本研究为政府等决策机构选择有效目标人群提供了参考依据.     

高原环境对直升机旋翼性能的影响分析

针对高原环境直升机旋翼性能的估算,建立了一个基于自由涡理论的旋翼尾迹模型,并推导了旋翼拉力和功率的计算方法。以UH-60黑鹰直升机为算例,分别计算了其在海平面及高原环境的旋翼性能,探讨了海拔高度对直升机旋翼性能的影响规律。计算结果表明,高原环境的气候条件对直升机旋翼性能有显著影响,旋翼拉力较海平面环境减小约30%。     

纳米级聚合氯化铝处理石化废水絮凝效果研究

采用自制的纳米级聚合氯化铝絮凝荆处理石大科技股份公司胜华炼油厂隔油池出水，以处理后水样的透光率作为混凝沉降效果的评价指标，并对絮凝剂投加量、搅拌速度、搅拌时间等影响混凝效果的因素进行了研究。试验表明，聚合氯化铝对石化废水的处理达到较为理想的效果，聚合氯化铝混凝处理石化废水的最佳条件为：纳米级聚合氯化铝投加量为15mg／L左右，慢速搅拌的搅拌速度为50～60rpm，快速搅拌的搅拌速度为190—225rpm，快速搅拌时间90s。慢速搅时间10min时效果最佳。使用Al-Ferron逐时络合比色法及XRD对絮凝荆进行了表征，结果证实样品中Alb含量可达到85％左右。     

Polybrominated diphenyl ethers in surface sediments from principal watersheds of Shanghai, China: levels, distribution, influencing factors, and risk assessment

Fourteen and 17 sediment samples were collected from three main rivers of Shanghai in July and November, respectively. Eight polybrominated diphenyl ether (PBDE) congeners (BDE-28, BDE-47, BDE-99, BDE-100, BDE-153, BDE-154, BDE-183, and BDE-209) were detected in these samples to clarify the pollution status in the metropolis. Instrumental analyses showed that the concentrations of ∑₈PBDEs ranged from 10.97 to 64.05 ng/g dry weight (dw), with an average value of 29.71 ng/g dw. BDE-209 was the predominant congener accounting for more than 97 % of total PBDEs, followed by BDE-47 and BDE-99. Remarkable spatial and seasonal distributions of PBDE concentrations were observed, suggesting that local sources, seasonal climates, and hydrologic conditions might be the influencing factors. Moderate correlations (r ²?=?0.28–0.51, p?<?0.05) were found between total organic carbon and PBDEs, which indicated that organic carbon content influenced the distributions of PBDEs in sediment of Shanghai at some extent. Hazard quotients revealed PBDEs posed no potential risk to benthic organisms in the study area at present.