Fenton复合调理剂对污泥脱水性能的影响研究

通过传统Fenton法、Fenton-表面活性剂法和Fenton-生石灰法进行污泥调理单因素实验.研究各单因素对调理效果的影响情况.对比单因素实验结果得出较合适的污泥调理方法为Fenton-生石灰法.最佳工艺参数是反应时间为30 min,反应温度为30℃,反应pH值为3,H2O2/Fe2+为2.5,Fe2+投加量为20 mg/gDS,Ca2+投加量为40 mg/gDS.经Fenton-生石灰法调理后污泥比阻降至0.58×108 s2/g,污泥脱水性能得到提高.     

净水工艺对饮用水中微生物多重耐药性的影响与分析

由于抗生素过量使用已导致我国部分水源受到多种抗生素和耐药基因的污染,抗生素及其耐药基因可能通过饮用水对人体健康造成严重威胁.对上海某水厂供水系统可培养微生物进行了分离鉴定;使用5种抗生素:氨苄青霉素(Amp)、卡那霉素(Kan)、利福平(Rif)、氯霉素(Cm)以及链霉素(Str)对饮用水中可培养微生物多重耐药性及其在供水系统中的变化规律和耐药机制进行了分析.结果表明:所分离可培养微生物主要属于16个属,其中芽孢杆菌属(Bacillus sp.)、噬纤维菌属(Arcicella rosea sp.)、鞘酯菌属(Sphingomonas sp.)在所有工艺单元中都可分离获得;经过生物活性炭滤池和管网输配后3种菌的多重耐药能力均有增强,其中芽孢杆菌属(Bacillus sp.)耐药能力最强.采用实时荧光定量PCR对供水系统中3种整合子及9种转座子进行定量检测,发现经过生物活性炭滤池和管网输配后,可移动基因元件绝对数量增加明显,生物活性炭滤池和输配管网对饮用水中微生物耐药能力具有重要影响.     

城市生活污水和生活垃圾渗滤液抗生素抗性基因污染的比较研究

为研究城市生活污水(接收生活垃圾渗滤液后合并进入污水厂处理)和垃圾渗滤液中抗生素抗性的分布格局,采用高通量荧光定量PCR技术对城市生活污水和生活垃圾渗滤液中的抗生素抗性基因的多样性和丰度进行了分析.结果表明,生活垃圾渗滤液中检测出39种抗性基因,城市生活污水中检测出187种抗性基因,两者检出的抗生素抗性种类有显著差异(P0.05);相对于垃圾渗滤液,城市生活污水抗生素抗性基因有119种显著增加(P0.05),其中增加倍数最大的是转座子tnp A-04基因,blaVEB基因,分别达到了3 338倍和1 061倍,表明可移动元件转座子基因和β-内酰胺类抗生素抗性基因在城市生活污水中得到有效富集和传播;城市生活污水是环境抗生素抗性基因的重要存储库.     

多核复合聚铝絮凝剂对水体残留铝的影响

采用分别添加金属离子Fe~(3+)和Zn~(2+)的方法制备多核复合型絮凝剂聚合氯化铝铁(PAFC)和聚合氯化铝锌(PAZC),并与市售聚合氯化铝(PAC)比较处理高岭土模拟水样后出水残留铝浓度,得出复合絮凝剂具有更低的出水余铝量及更宽的pH适用范围以及更低的投加量。达到85%COD去除率,PAZC、PAFC和PAC用量分别为5、10和20 mg/L;处理后出水残余铝量分别为0.04、0.09和0.14 mg/L;处理成本分别为0.020、0.028和0.048元/t。     

低湿诱导黄瓜抗病性研究

以黄瓜感病品种为试材，在国内外首次证实低湿处理诱导抗黄瓜病害的现象。研究证实，黄瓜幼苗经低湿处理7d后，对霜霉病、炭疽病、黑星病产生抗性。低湿程度不同，诱导效果也不同，1／2、1／3正常浇水量对黄瓜抗霜霉病有明显诱导作用；1／3、1／4正常浇水量对黄瓜抗炭疽和黑星病有明显诱导作用，诱导抗性持续时间可达到12d。     

Coastal mudflats as reservoirs of extracellular antibiotic resistance genes: Studies in Eastern China

Despite coastal mudflats serving as essential ecological zones interconnecting terrestrial/freshwater and marine systems, little is known about the profiles of antibiotic resistance genes (ARGs) in this area. In this study, characteristics of typical ARGs, involving both intracellular (iARGs) and extracellular ARGs (eARGs) at different physical states, were explored in over 1000 km of coastal mudflats in Eastern China. Results indicated the presence of iARGs and eARGs at states of both freely present or attached by particles. The abundance of eARGs was significantly higher than that of iARGs (87.3% vs 12.7%), and their dominance was more significant than those in other habitats (52.7%-76.3%). ARG abundance, especially for eARGs, showed an increasing trend (p < 0.05) from southern (Nantong) to northern (Lianyungang) coastal mudflats. Higher salinity facilitated the transformation from iARGs to eARGs, and smaller soil particle size was conducive to the persistence of eARGs in northern coastal mudflats. This study addresses the neglected function of coastal mudflats as eARGs reservoirs.     

苯甲酸类化合物的微生物降解研究

用富集培养法从工业污水中分离到5个能以苯甲酸为唯一碳源和能源而生长的细苗菌株：不动杆菌（Acinetobactersp.）BJ1，无色杆菌（Achromobactersp.）BY1，假单胞苗（Pseudomonasspp.）SJ1、SY1和SH1、测定了这5个菌株的底物特异性和抗菌素抗性其中BJ1菌株含有1个大质粒和2个小质位在最适培养条件下BJ1菌株对苯甲酸的降解率达98％以上．     

人工BSCs对稀土尾砂理化性质及抗蚀性的影响

以赣州市定南县岭北镇一座离子型稀土矿尾砂为研究对象,通过采集现场生物土壤结皮与尾砂,采用碎皮接种法在尾砂上培育人工生物土壤结皮(BSCs),以不接种BSCs的尾砂作为对照组,对比分析人工BSCs对离子型稀土矿尾砂的改良作用.在结皮发育300d后,分析了结皮下层尾砂的pH值,容重,有机质含量,全量和速效养分含量,机械组成等基本理化性质,以及土壤侵蚀,土壤径流,保水性能等水文性质.结果表明,碎皮接种法可在短期内快速培育出人工BSCs,且人工BSCs的发育对离子型稀土矿尾砂的理化和水文性质都具有积极影响,与对照相比pH值从5.88提高至6.28,提高了6.8%,土壤酸性减弱;容重降低了11.6%,有机质,全氮,速效氮,全磷,速效磷,全钾,速效钾分别提高了294%,21.6%,81.8%,100%,260%,8.9%和52.4%;粉粒和粘粒的组成有少量提高,土壤被粘化;土壤抗侵蚀能力和保水性能均有显著提高.研究表明适宜的人工生物土壤结皮技术是稀土矿山生态修复的有效选择之一.     

DDT residues in water, sediment, domestic and indigenous biota from a currently DDT-sprayed area

DDT is used for indoor residual spraying (IRS) in Limpopo Province, northern South Africa to control malaria. Through IRS, DDT may reach the outdoor environment via dust and air and from possible spillages during application. In this area the local people consume domestic chickens, wild fish or birds. Fish from the river catchment and impoundments seem to be the major source of protein intake. Water, sediment and tissue samples from two such fish species, domestic chickens and wild birds (terrestrial and aquatic) from this DDT-sprayed area were analysed for DDT and metabolite residues. The samples contained p,p′-DDT, p,p′-DDD and p,p′-DDE residues, with the latter the most ubiquitous and in the highest concentrations. These findings raise concern that both water and food may be major routes of human exposure to DDT and metabolites, thereby posing possible adverse human health implications to the local communities.