The Application Of Composite Filter Material In Wastewater Advanced Treatment

In recent years, more stringent standards of wastewater discharge are enforced inChina. As the result, many wastewater treatment facilities cannot meet these dischargestandards. Under these circumstances, the advanced treatment measures have to beused in the current treatment facilities.The filtration technology is one of the methods which are more economically andpractically. Based on the filtration technology, the paper consisted of4experiments:the static and dynamic experiment, compounded filtering materials experiment andcombining processes experiment. The static experiment studied with the factors of pHvalue, adsorption time and dose adding amount to the adsorption effect of zeolite andactivated carbon. The dynamic experiment investigated the influence of filtering loadto zeolite and activated carbon removing ammonia and COD_cr. The filtrationexperiment compared the treatment efficiency of3compounded filtering materials:zeolite-activated carbon, zeolite-ceramsite, zeolite-biological fiber balls, whichobtained the best filtering material and the optimum quality ratio. The experiment ofcoagulation, membrane and ozone oxidation technology and compounded filteringmaterials respectively were taken. The results are as follows:（1） The static experiment: the maximum adsorption value of ammonia nitrogenwas0.51moL/kg. The removal rate of ammonia nitrogen was increased with theamount of additive, the optimum value was20g, corresponding removal rate was39.87%. When the pH is6, ammonia nitrogen removal efficiency is best. Ammonianitrogen removal rate was increased with the extension of time, the optimum valuewas40min. The experimental results of activated carbon indicated that the removalrate of COD_crwas increased with incremental quantity, but the removal rate becamestable after30minutes. The temperature and pH on the activated carbon have littleeffect on removal of COD_cr.（2） The dynamic experiment: the removal rate of ammonia nitrogen by zeolitecolumn was76.09%, when replaced by biological zeolite column, the removal ratewas88.19%; The dynamic experiment of activated carbon showed that the reasonablefiltered load was2.5m3/m2·h.（3） The experiment results of the efficiency of the compounded filteringmaterials showed that the removal rate which from top to down: the zeolite and activated carbon, zeolite and ceramsite, zeolite and biological fiber ball. The optimumquality rate （zeolite/activated carbon） was of2:1.（4） Comprehensive considering the factors of economy and operation, the zeoliteand activated carbon compound materials plus coagulation is the best method forammonia nitrogen and COD_crtreatment, the removal rate of ammonia nitrogen andCOD_crcould reach65.36%and37.36%respectively.