Characterization of permanent fouling on the surfaces of UV lamps used for wastewater disinfection.

A significant problem with UV disinfection of wastewater is the accumulation of fouling materials at sleeve-water interfaces. It has been shown that automated chemical and/or mechanical cleaning can remove most fouling materials satisfactorily. However, permanent foulants, which cannot be removed completely by typical cleaning operations, always remain on the quartz sleeves. These permanent foulants reduce UV transmittance, in turn reducing disinfecting effectiveness. This research investigated the origins, formation, and composition of permanent fouling. Four instrumental analyses were used: atomic force microscope (AFM), X-ray fluorescence (XRF), scanning electron microscope combined with energy dispersive X-ray microanalysis (SEM/EDX), and sleeve UV transmittance (SUVT). It appeared that permanent foulants were trapped initially by microscale holes and peaks on fresh sleeve surfaces. Based on the topography and roughness measurements from the AFM, after long-term regular chemical and mechanical cleaning, the wipers of cleaning systems damage sleeve surfaces, creating scratches or holes with larger surface areas. Foulants are trapped more easily, and are attached tightly to the surfaces of these scratches or to each other. The results from XRF and SEM/EDX showed that the main fouling components were aluminum, iron, magnesium, calcium, and phosphorus. These could not be related to wastewater quality. For the specific cases studied, chemical plus mechanical cleaning is more effective in removing foulants and avoiding the accumulation of permanent foulants than mechanical cleaning alone; in most cases, SUVT was higher than 90% after chemical plus mechanical cleaning, whereas mechanical cleaning alone achieved only approximately 30% SUVT after long-term usage.     

Effects of grassland degradation on chestnut soil properties in Bashang Plateau, China

ＩｎｔｒｏｄｕｃｔｉｏｎＣｈｅｓｔｎｕｔｓｏｉｌｏｎｔｈｅＢａｓｈａｎｇＰｌａｔｅａｕｉｓｏｎｅｏｆｔｈｅｓｏｉｌｓｉｎｚｏｎａｌｄｉｓｔｒｉｂｕｔｉｏｎ.Ｔｈｅｄｅｇｒａｄａｔｉｏｎｏｆｔｈｅｃｈｅｓｔｎｕｔｓｏｉｌｒｅｓｕｌｔｅｄｆｒｏｍｔｈｅｅ?..     

含取代苯胺类化合物工业废水的电解处理研究

在酸性条件下投加ＮａＣｌ对含取代基团的苯胺类废水，进行了电解和过滤循环的处理。对含氯苯胺、硝基苯胺、甲苯胺等１２种废水进行处理试验，结果表明，在实验条件下电解１．０～２．０ｈ后，含１０００ｍｇ／Ｌ左右的苯胺类废水的出水ＣＯＤｃｒ＜２５０ｍｇ／Ｌ，芳胺含量＜３ｍｇ／Ｌ。采用质谱法分析了部分芳胺的电解固体产物，并对反应机理进行了探讨。     

建设生态社区的若干思考

建设生态社区作为２１世纪解决人类居住地环境恶化和生态破坏问题的方法，正日益受到重视和肯定。生态学在城市社区规划和建设中的应用为社区研究提供了指导思想和理论依据。本文尝试用生态学的基本原理探讨社区建设中社区规模、生态流、可持续性等问题，寻求社会、经济、自然三个子系统持续发展的生态社区规划和建设的途径。     

煅烧对粉煤灰合成4A沸石的作用

研究了煅烧对粉煤灰合成4A沸石除炭(有机物)增白和活化的两个作用,试验确定了粉煤灰最佳的锻烧条件:温度为850℃,时间为2h。在此条件下煅烧,通过XRD、SEM分折和白度测定,结果显示:破坏了粉煤灰中的晶相结构和溶解了玻璃体,白度达到了63。     

乌梁素海鱼类种群变化的研究

根据乌梁素海实地调查和资料分析 ,对乌梁素海鱼类种类、区系特征、鱼类种群现状及变化进行分析 ,并提出保护鱼类种群及鱼类资源的建议     

投资项目环境经济分析的几个问题

投资项目技术经济分析中环境经济分析是非常重要的一个方面，但目前由于经济核算统计指标的某些缺陷，使得项目环境效果与经济效果常常出现矛盾，相互间的转化也较困难，因此，在投资项目环境经济分析中出现了方法上的不足。本文对项目环境经济分析的现状进行了研究，提出了一些新的思路和方法。     

环渤海湾诸河口底质现状的调查研究

20 0 1年 6月实地采集了环渤海湾诸河口 19处土样 ,进行了汞、铜、锌、铅、砷、总氮、总磷和有机质含量分析 ,发现环渤海湾诸河口底泥中基本无重金属 (及砷 )污染 ,但与历史资料相比 ,近年来重金属含量普遍增加 ,特别是铅和锌含量增加幅度较大 .大多数河口底泥中的总氮和总磷含量较高 ,尤其是海河口附近的河口总氮和总磷含量高达 0 14%和 0 0 9%,通过与水体的交换 ,将对水体富营养化产生影响 .     

Ecological toxicity of reactive X-3B red dye and cadmium acting on wheat (Triticum aestivum)

ＩｎｔｒｏｄｕｃｔｉｏｎＷｉｔｈｔｈｅｉｎｃｒｅａｓｉｎｇｖａｒｉｅｔｉｅｓａｎｄｑｕａｎｔｉｔｉｅｓｏｆｄｙｅｓｅｎｔｅｒｉｎｇｉｎｔｏｔｈｅｅｎｖｉｒｏｎｍｅｎｔ,ｄｙｅｓ,ａｓａｎｉｍｐｏｒｔａｎｔｔｙｐｅｏｆｐｏｌｌｕｔａｎｔｓ,ｈａｖｅａｎａｄｖｅｒｓｅｅｆｆｅｃｔｏｎｗａｔｅｒ ｓｏｉｌ ｐｌａｎｔｓｙｓｔｅｍｓ ,ａｃｃｏｒｄｉｎｇｔｏｓｏｍｅｅｘｐｅｒｉｍｅｎｔａｌｒｅｓｕｌｔｓ(Ｃｈｅｎｇ ,ｉｎｐｒｅｓｓ) .ＩｎｔｈｅｅａｓｔｅｒｎＣｈｉｎａ ,ｉｎｄｕｓｔｒｉａｌｗａｓｔｅｗａｔｅｒｆ…