A new process for the removal of colloidal particles from waste liquid by use of particle immobilization in gel

提出了一种利用凝胶中颗粒固定化的新技术，用于难过滤胶体悬浮液的固液分离。将藻酸盐水溶液和胶体悬浮液的混合物逐滴加入氯化钙水溶液中，得到藻酸钙凝胶。胶体颗粒被固定在凝胶中。凝胶悬浮液通过重力脱液，然后机械挤压凝胶颗粒。在挤出过程中，胶体颗粒保留在凝胶中，并且挤出的液体是澄清的。最后将挤出的滤饼丢弃。该技术的基本方面进行了研究，通过使用两种胶体材料：车蜡和环己烷乳液。该技术能有效地去除乳化液中的蜡和环己烷。为了将该技术扩展到去除溶解有机物，将上述过程与吸附过程相结合。甲苯胺蓝（TB）用作溶解有机物。它被胶体二氧化硅颗粒吸附。吸附剂（胶体二氧化硅颗粒）在海藻酸盐凝胶中起着重要的作用，以保留溶解的物质。从非水性胶体分散体系中去除胶体颗粒也可以通过使用颗粒固定化技术来实现。研究了12-羟基硬脂酸在植物油中的凝胶作用。将含有直径为0.15 μm的聚甲基丙烯酸甲酯（PMMA）颗粒的油与12-羟基硬脂酸混合。使截留PMMA颗粒的有机凝胶脱液。它表明，CA。当原始油-颗粒混合物中的PMMA浓度大于1，000 ppm时，10%的PMMA颗粒从凝胶中逸出。结果表明，混合物中PMMA的浓度越高，挤出液中PMMA的浓度越低。

A new technique utilizing particle immobilization in gels has been proposed for a solid-liquid separation of difficult-to-filter colloidal suspensions. A mixture of alginate aqueous solution and colloidal suspension is added dropwise to a calcium chloride aqueous solution, resulting in calcium alginate gels. Colloidal particles are immobilized in the gels. The gel suspension is deliquored gravitationally, followed by mechanical expression of the gel particles. During the expression, the colloidal particles remain in the gels and the expressed liquid is clear. The expressed cake is finally discarded. Fundamental aspects of this technique are investigated by use of two kinds of colloidal materials : car wax and cyclohexane emulsions. The car wax and cyclohexane in the emulsion are effectively removed by this technique. To extend this technique for removal of dissolved organic matter, the above process is combined with adsorption process. Toluidine blue (TB) is used as dissolved organic matter. It is adsorbed by colloidal silica particles. The adsorbents (colloidal silica particles) play an important role to retain dissolved matter in alginate gel. Removal of colloidal particles from non-aqueous colloidal dispersion system can also be attained by use of the particle immobilization technique. This technique is investigated by use of gelation of 12-hydroxy stearic acid in vegetable oil. The oil containing polymethyl metacrylate (PMMA) particles of 0.15 μm in diameter is mixed with 12-hydroxyl stearic acid. The organogel entrapping PMMA particles are deliquored. It is shown that ca. 10 % of PMMA particles escaped from the gel, when the PMMA concentration in original oil-particle mixture is more than 1,000 ppm. It is found that the higher the concentration of PMMA in the mixture, the lower the concentration of PMMA in squeezed liquid.