Preparation And Applied Research Of Carboxymethylstach Preparation And Application

In this paper, with starch as material, the factors which affect DS of Carboxymethyl starch,the properties of carboxymethyl starch flocculation are studies.Carboxymethyl starch was prepared in alcohol medium by chloroactic acid and sodium hydroxide. We studied the different factors in preparation on degree of substitution (DS) of Carboxymethyl starch, which include the dosage of chloractic acid, the dosage of sodium hydroxide, the concentration of ethanol, by the reaction temperature and the reaction time. The result indicated that at first the DS of Carboxymethyl starch increased then decreased in a range of dosage. On the basis of one-factor experiments , we select the ration of starch, chloractic acid and sodium hydroxide, the concentration of ethanol, the reaction temperature and the reaction time as the variables, DS as the experiments index, using L₁₆(4⁵) orthogonal experiment, we obtain the optimum processing conditions for preparation starch: chloroactic acid 0.075mol, sodium hydroxide0.2mol, reaction temperature 50℃, ethanol 70ml.During the process of wastewater treatment, the flocculation is one of very common techniques. The flocculent is the key of this technique, and its properties influence directly flocculation efficiency. The requirement of water quality becomes more and more strict. Therefore, researching in high effective and environmentally is always a project on which scientists of water treatment. Concentrate.The properties of carboxymethyl starch flocculation are studies in kaolinite containing suspension. The experimental results show that. The remaining turbidity in treated water decreased to 3.2NTU after adding 4mg/L carboxymethyl starch., the flocculation experiment of carboxymethyl starch as coagulant aid indicated that turbidity removal ratios are larger than 90%.after adding 8mg/L PAC within 0.2mg/L carboxymethyl starch.The experimental results of CMS and PAC as coagulant show that, turbidity removal ratios reach 90%, and the more quantity of PAC is need compared with CMS. Because of price and quality change, PAC is the popular coagulant. CMS show high performance as coagulant aid...