Study On Preparation Of Modified Diatomite And Its Performance In River Water Purification

River’s pollution is our country one of the major water pollution situation of attention in recent years.In order to effectively remove the pollutants in the river water,some environmental protection,low cost,rapid adsorption on water pollution for a new type of functional composites are constantly attention and research.Diatomaceous earth is not only a unique porous structure,large specific surface area,makes it easy to modify and has a good adsorption performance,and is abundant in our country,the cost is low.Therefore,use of diatomite composite materials to deal with water pollutants in also gradually become a hot spot.In this paper,the bitter in nanan distract of chongqing city river water quality was evaluated.The original diatomaceous earth（diatomite,DE）by water bath-acid leaching purification,reoccupy red mud（red mud,the RM）on the modification,then respectively in homemade polyaluminium chloride（PAFC）and PAFC sold iron compound with,finally modified diatomite with red mud（RM/DE）,commercial PAFC/RM/DE,homemade PAFC/RM/DE three kinds of materials.In river water as the research object,test three kinds of materials under different conditions of water samples in TN and NH4+-n,TP,CODCr removal effect,and put forward the idea of a mobile reaction filter wall with self-made modified DE as the main filling medium.The specific research is as follows:（1）bitter springs of water quality evaluation using the comprehensive water quality identification index evaluation method,considering the effect of a single water quality factor,and considering the interaction between multiple water quality factor.The results show that bitter river water quality is worseⅤclass,but not black smelly,belongs to the mild pollution,TN and TP pollution.（2）in the RM/DE preparation experiment,through the single factor experiment find DE and the proportion of the RM,calcination temperature and purifying calcining time optimal numerical interval,and then find the three conditions by using the method of response surface optimization optimal combination way,through the regression equation numerical optimization.The results showed that the preparation of the RM/DE the best process conditions for:calcination temperature 700℃,calcination time 2 h,DE and the proportion of the RM 5:5 and the TN,NH₄⁺-N,TP and CODcr removal rate,respectively Proto-diatomite,purified DE and RM/DE were characterized by means of SEM,BET,XRD and FTIR.（3）The prepared RM/DE was used in the removal experiment of pollutants in water samples,and the effects of different conditions on the removal effect were studied.The results showed that the comprehensive removal effect of TP,TN,CODCr and NH₄⁺-N in water samples was the best when the dosage was 4 g/L,the reaction time was 60min and the pH was 4,and the removal rates were 83%,42%,37%and40%,respectively.（4）the preparation of homemade PAFC/RM/DE for the removal of pollutants in water samples,the experiment studied the influence of different conditions on the removal efficiency.The homemade PAFC with RM/DE distribution ratio of 1:20,water samples from the initial pH of 7,the reaction time for 30 min,dosing quantity is2.2 g/L of water samples in the TP,TN,CODcr,NH₄⁺-N removal effect is best,94%,38%,42%and 46%respectively.（5）the preparation of commercial PAFC/RM/DE for the removal of pollutants in water samples,the experiment studied the influence of different conditions on the removal efficiency.Commercially available PAFC and RM/DE compound with a ratio of 1:6,initial pH of 6 water,reaction time is 20 min,dosing quantity is 4.2 g/L of water samples in the TP,TN,CODcr,NH₄⁺-N removal effect is best,92%,35%,37%and 43%respectively.The above results show that the modified diatomite has a good purification effect on river water,especially the removal effect of TP in water is better.The study of modified diatomite provides certain theoretical guidance for the application of diatomite based materials and the development of new water treatment materials,which has great research significance.