Activity of nucleoside triphosphate diphosphohydrolase, 5′-nucleotidase,and adenosine deaminase in cattle fed on pastures treated with different nitrogen fertilizers

The aim of this study was to evaluate nucleoside triphosphate diphosphohydrolase, 5′-nucleotidase, and adenosine deaminase activities in cattle fed on cuttings from pastures fertilized with urea compared to animals fed on cuttings from organically fertilized or from non-fertilized pastures. Blood samples were collected up to 9 h after feeding, and nitrite and enzyme activities were evaluated. The animals feeding on urea-fertilized pasture suffered subclinical intoxication. Serum nitrite levels increased by about 50% and adenosine deaminase activity increased almost sixfold 4 and 6 h after feeding on urea-fertilized pasture, and adenosine deaminase in platelets almost doubled 6 and 9 h after feeding. In platelets, nucleoside triphosphate diphosphohydrolase activity with adenosine triphosphate as substrate increased 2, 4, 6 and 9 h after feeding while nucleoside triphosphate diphosphohydrolase with adenosine diphosphate as substrate and 5′-nucleotidase activities increased only 9 h after feeding. Increased activities of these enzymes may be implicated in the pathophysiology of subclinical intoxication since they are involved in many biochemical functions.     

油田注汽锅炉烟气余热利用与低碳减排

通过对注汽锅炉烟气余热利用潜力的分析及开展余热利用方式对比分析,采用在注汽锅炉对流段上安装热管换热器,使高温烟气与助燃空气换热,利用换热器回收烟气余热。该技术的现场应用,实现了注汽锅炉燃料单耗降低和污染物排放量降低的目的,取得了良好的节能、减排效果。     

全氟辛烷磺酸盐(PFOS)在藻渣/小球藻上的吸附行为及机理

为了开发新型廉价生物吸附剂,以高效吸附去除水体中全氟辛烷磺酸盐(PFOS),对小球藻提取生物柴油后的藻渣吸附酸性水体中的PFOS进行了吸附行为及机理的研究。小球藻提取生物质柴油后,比表面积、孔容、孔径几乎没有变化;等电点由3.3降低至2.7;蛋白质含量由51.45%提高到57.35%。在酸性条件下(pH≤3),小球藻和藻渣对PFOS的吸附率均达到99%以上;随着pH值增加至7,二者的吸附去除率迅速降低,但仍保持在22%~26%。小球藻和藻渣对PFOS的最大吸附容量分别为353.69 mg/g和444.83 mg/g。Freundlich模型能较好地拟合二者对PFOS的吸附数据,表明为多层吸附,即小球藻以静电吸引的形式吸附PFOS阴离子,并疏水分配至所含蛋白质中;而藻渣中含量较高的蛋白质对PFOS的疏水性分配作用是导致藻渣吸附量增高的主要原因。     

纳滤去除饮用水中的PFOS

全氟辛烷磺酸类物质（PFOS）是一种新型持久性有机污染物,对人类健康存在很大威胁,目前世界范围内的水体中均检测到不同浓度的PFOS。研究如何安全有效去除这类新型污染物十分必要。利用HYDRA—COPe10纳滤膜进行PFOS去除研究,在不同操作压力下研究pH、电解质以及与腐殖酸共存对PFOS截留效果的影响。结果表明,随着pH值的增加,截留率上升;二价盐对PFOS截留率的影响要高于一价盐,并且随着二价盐离子强度的增加,截留率上升;腐殖酸共存时截留效率有显著增加,尤其在1mmol／L钙离子存在条件下,PFOS的截留率可达到95．8％,但会引起膜通量下降及膜污染的发生。     

赤泥复合剂絮凝处理太湖水华藻与海洋赤潮藻

研究了一种新型赤泥复合剂对太湖夏季水华原水、实验室培养海洋赤潮藻及模拟海水的絮凝除藻降浊性能。结果表明,赤泥复合剂具有良好的除藻降浊效果,对太湖水华藻去除率为97.3%,原水浊度去除率为95%;对海洋小球藻和三角褐指藻2种赤潮藻去除率分别高达99.1%和98.9%;对2种模拟海水的最高除浊率分别为96.3%和95.3%,其剩余浊度均低于4 NTU,从而为治理淡水水华与海洋赤潮提供一种新技术,同时为赤泥综合利用提供一种新途径。     

聚合氯化铝和聚合硫酸铁对水中亚硒酸盐的去除研究

为达到快速有效去除饮用水中亚硒酸盐的目的,通过混凝法考察了聚合氯化铝与聚合硫酸铁对模拟硒污染饮用水源中亚硒酸盐的去除效果,探讨了初始浓度、投加量以及pH对去除效果的影响。结果表明,混凝工艺对水中亚硒酸盐的去除效果明显,在初始硒浓度为184／μg／L时,聚合氯化铝和聚合硫酸铁对亚硒酸盐的最大去除率分别为70％和97％。聚合硫酸铁对亚硒酸盐的混凝去除效果明显好于聚合氯化铝,其最佳除硒pH为8。     

Removal of heavy metals from aqueous solution by carbon nanotubes: adsorption equilibrium and kinetics

IntroductionWastewatersfrombatterymanufacturing ,printing ,painting ,dyeingandotherindustrialprocessesoftencontainconsiderableamountsofheavymetalsthatwouldendangerpublichealthifdischargedwithoutadequatetreatment.Long termingestionofwatercontaininghigherco…     

Bubble performance of a novel dissolved air flotation(DAF) unit

ES-DAF, a novel DAF with low cost, high reliability and easy controllability, was studied. Without a costly air saturator, ESDAF consists of an ejector and a static mixer between the pressure side and suction side of the recycle rotary pump. The bubble size distribution in this novel unit was studied in detail by using a newly developed CCD imagination through a microscope. Compared with MDAF under the same saturation pressure, ES-DAF can produce smaller bubble size and higher bubble volume concentration, especially in lower pressure. In addition, the bubble size decreases with the increase of reflux ratio or decrease of superficial air-water ratio. These results suggested that smaller bubbles will be formed when the initial number of nucleation sites increases by enhancing the turbulence intensity in the saturation system.     

天然气供气业务风险分析与应急预案设计

天然气市场需求量的大幅度增加与国内天然气供给不足造成的供需不平衡,给天然气供气业务带来了极大的挑战。根据近两年来天然气供应面临的危机,分别对天然气供气产业链的上、中、下游的突发事件风险进行分析;并针对供气业务中断带来的风险,从突发事件分级、应急处置流程等两个关键要素着手对应急预案进行优化。该研究对完善天然气供气突发事件应急预案、有效快速应对突发事件提供了参考和指导。     

Submerged anaerobic membrane bioreactor for low-concentration domestic sewage treatment: performance and membrane fouling

Environmental Science and Pollution Research - A submerged anaerobic membrane bioreactor (SAnMBR) was used to treat low-concentration domestic sewage. The effects of hydraulic retention time (HRT)...