CrⅥ adsorption on four typical soil colloids: equilibrium and kinetics

It is observed that the adsorption of chromium are greater on kaolinite minerals, red soil (R) and laterite (L) colloids than that on montmorillonite, indicotic black (IB) and yellow brown (YB) soil colloids. The adsorption process of CrⅥ on these media can be further described by Langmuir or Freundlich equation quite well. The adsorption reaction of CrⅥ is fast, and the adsorption equilibrium can be reached within the first two hours in moderate temperature. The adsorption quantity of CrⅥ to kaolinite mineral increased with the increasing pH in the range of 2.0 to 7.0, then decreased at higher pH. But it showed some consistence among the four soil colloids. The lower the pH, the stronger the adsorption. The possible mechanisms are further discussed here. Meanwhile the influence of temperature on CrⅥ adsorption on different soil colloid and clay minerals are also investigated.     

Protozoan colonization on artificial substrates in relation to water quality in a tropical Indian harbour

ＩｎｔｒｏｄｕｃｔｉｏｎＩｎａｑｕａｔｉｃｅｃｏｓｙｓｔｅｍｓｂｉｏｌｏｇｉｃａｌｃｏｍｍｕｎｉｔｉｅｓａｒｅｒｅｍａｒｋａｂｌｙｃｏｍｐｌｅｘｉｎｂｏｔｈｔｈｅｉｒｏｐｅｒａｔｉｏｎａｎｄｒｅｓｐｏｎｓｅｔｏａｎｔｈｒｏｐｏｇｅｎｉｃａｃｔｉｖｉｔｉｅｓ.Ｔｈｉｓｈａｓｌｅｄｍａｎｙｉｎｖｅｓｔｉｇａｔｏｒｓｔｏｃｏｎｄｕｃｔｌａｂｏｒａｔｏｒｙａｎｄｆｉｅｌｄｓｔｕｄｉｅｓｆｏｒｅｖａｌｕａｔｉｎｇｔｈｅｅｃｏｌｏｇｉｃａｌｒｉｓｋｐｏｓｅｄｂｙｈｕｍａｎｓｔｏｅｃｏｓｙｓｔｅｍ(Ｃａｉｒｎｓ…     

改进密切值法在湖泊富营养化评价中的应用

密切值法(Osculating Method)作为一种多目标优选方法,在水环境质量评价中具有一定的应用.经过改进,将各级营养级别作为评价样本,参与到湖泊水环境样本的矩阵中,引入目标差值率对初始矩阵进行规范化处理,并应用层次分析法,对各评价指标的贡献程度加以确定.将改进后的密切值法应用于湖泊富营养化评价中.经实例分析表明,该方法概念清晰、计算简便实用,保证了湖泊水环境质量评价的科学性,能较好地反映湖泊水环境质量的优劣,并使其与各级营养级别的关系一目了然.     

Adsorption selectivity of salicylic acid and 5-sulfosalicylic acid onto hypercrosslinked polymeric adsorbents

Both bottle-point and column-feeding experiments involving different solutes and sorbents were carried out to investigate the adsorption selectivity and separation performance of salicylic acid and 5-sulfosalicylic acid. Their adsorption isotherms onto such hypercrosslinked polymeric adsorbents as NDA-100 and NDA-99 could be well described by the Freundlich equations whose characteristics describe extrathermic and favorable adsorption processes. The adsorption towards NDA-100 mainly depended on the π-π interaction, while that towards NDA-99 was extremely influenced by the static-electric interaction. Additionally, the adsorptive capacity of salicylic acid on NDA-99 decreased while it increased on NDA-100 with the presence of 5-sulfosalicylic acid in the adsorptive environment as the competitive component. Comparatively, the adsorption capacity of 5-sulfosalicylic acid decreased on both resins with salicylic acid as the competitive component. In fact, the difference in the interaction between adsorbent and adsorbate resulted in the straight antagonism on the effective adsorption sites on the adsorbent. In conclusion, the adsorption selectivity of salicylic acid onto NDA-100 was obviously larger than that onto NDA-99 with the existence of 5-sulfosalicylic acid in the adsorptive environment. A satisfactory separation and recovery of tested solutes in aqueous phase could be foreseeably achieved by the sequencing adsorption technique involving NDA-100 as well as NDA-99. Translated from Environmental Pollution & Control, 2005, 27(8): 570–574 [译自: 环境污染与防治]     

清洁的胡椒基T醚生产工艺的研究I,5-丙基-1,3-苯并二氧杂茂的氯甲基化废水的处理

报道了胡椒基丁醚生产中５－丙基－１，３－苯并二氧杂茂的氯甲基化的废水处理，该废水经蒸馏可回收９４％的盐酸，此酸吸收氯化氢后浓度在３６％以上，可再用于氯甲基化反应。蒸馏残液经分油、Ｆｅｎｔｏｎ试剂处理和五次生炭柱吸附后ＣＯＤＣｒ等项指标均可国家二类污染物的一级排放标准。     

利用废渣废碱液年产3000t粒状五水偏硅酸钠工艺初步设计

介绍以铝矾土提取硫酸铝废渣和氧氯化锆副产废碱液为原料生产泡花碱 ,然后利用一次造粒法生产五水偏硅酸钠新工艺确定影响产品质量指标工艺因素。小试试验产品质量指标达到HG/T2 5 6 8- 94要求 ,工艺成本低 ,避免废碱液及废渣排放对环境的污染。     

废水处理实用公式的推导计算

介绍由一级动力学模式推导废水处理实用公式。文中探讨了２０℃降解速率系数Ｋ２０和温度修正系数θ，仅是某种水质和生化条件下的对应值，不能任意通用。     

天然矿石毒重石吸附硫酸盐废水的试验研究

利用天然矿石毒重石对硫酸盐废水进行吸附处理，在废水的pH=9，停留时间为80min左右时，该吸附剂具有较好的吸附效果。且该离子交换吸附法具有成本低、操作简单、无二次污染的优点。     

黄磷尾气净化方法探讨

黄磷尾气的主要成分是CO，可作为燃料和碳一化工原料。综合论述了黄磷尾气的几种净化方法，对其净化效果进行比较，并对净化后的尾气用途作了简单介绍。分析了黄磷尾气净化的难点。     

序批式反应器的水力停留时间的理论探讨

根据液龄分布函数是二元函数的观点．推导出了当进、出水流量是时间的函数时，反应器的水力停留时间的通用积分式和离散式；然后得出了序批式反应器(SBR）的水力停留时间(HRT)具体表达式，并分析了用现有方法计算其水力停留时间所产生的误差．结果表明，最大相对误差rmax仅与充水比λ有关．且呈正相关关系．取典型值λ=0．4时，rmax高达25％。