Pollutant removal from municipal wastewater employing baffled subsurface flow and integrated surface flow-floating treatment wetlands

This article reports pollutant removal performances of baffled subsurface flow, and integrated surface flow-floating treatment wetland units, when arranged in series for the treatment of municipal wastewater in Bangladesh. The wetland units （of the hybrid system） included organic, inorganic media, and were planted with nineteen types of macrophytes. The wetland train was operated under hydraulic loading fluctuation and seasonal variation. The performance analyses （across the wetland units） illustrated simultaneous denitrification and organics removal rates in the first stage vertical flow wetland, due to organic carbon leaching from the employed organic media. Higher mean organics removal rates （656.0 g COD]（m2.day）） did not completely inhibit nitrification in the first stage vertical flow system; such pattern could be linked to effective utilization of the trapped oxygen, as the flow was directed throughout the media by the baffle walls. Second stage horizontal flow wetland showed enhanced biodegradable organics removal, which depleted organic carbon availability for denitrification. The final stage integrated wetland system allowed further nitrogen removal from wastewater, via nutrient uptake by plant roots （along with nitrification）, and generation of organic carbon （by the dead macrophytes） to support denitrification. The system achieved higher E. coli mortality through protozoa predation, E. coli oxidation, and destruction by UV radiation. In general, enhanced pollutant removal efflciencies as demonstrated by the structurally modified hybrid wetland system signify the necessity of such modification, when operated under adverse conditions such as： substantial input organics loading, hydraulic loading fluctuation, and seasonal variation.     

如何抢救烧伤者

如果发现有人被烧伤,应及时带伤者离开热源,脱去着火的衣服,迅速用冷水冲洗被烧伤的部位,达到减轻痛苦、减少损伤的目的。一般来说,小面积烧伤后用冷水浸泡的时间越早,治疗效果越好。浸泡时间应持续20至30分钟,至疼痛减轻或消失为止。     

海水网箱养殖大黄鱼细菌性病原鉴定与感染治疗研究

从患病大黄鱼的肌肉,肝、肾等病灶中分离出7种菌株,经人工感染试验证明,菌株970709A,970918a和970709B为致病菌,这三株菌株进行人工感染,死亡率均为100％,症状与自然发病相似,经菌体形态特征,生理生化特性反应测定,菌株970909A和970918a为鳗弧菌（Vibrio anguillarum),菌株970909B为副溶血弧菌（V.parahaemolyticus),药敏实验结果表明,氧氟沙星,环丙沙星,培氟沙星,罗红霉素,氯霉素和海鱼宁II等对致病菌有较强的抑制作用。临床治疗试验还表明,复方制剂海鱼宁II对大黄鱼弧菌病的治疗效果显著,有效率达66％－68％。     

如何走出中毒事故的阴影

经历过中毒事故的人,常常会心有余悸,这是一种正常的现象。然而,值得注意的是,有些人的“余悸”却演变成心身症或心身性反应。2004年10月,某市一家玻璃厂发生了二硫化碳泄漏事故,年轻女工小陈急性中毒,当时她四肢抽搐、剧烈呕吐、不省人事。急送医院抢救,2个月后小陈痊愈出院了。但回厂上班后,她一进车间闻到二硫化碳气味就呕吐,持续几个月无法工作,只好调离玻璃生产车间。像小陈这样,从事有毒有害作业的员工遭受重大中毒事故后,事故的阴影积聚心头,久久不散,严重时还会出现一系列症状,临床医学称为“心身症或心身性反应。”俗话说,一朝被蛇…