Research On Treatment For Rural Domestic Sewage By Immobilized Cells On The Zeolit

Jinyun zeolit is a kind of clinoptilolite of calcium-type and sodium-type or sodium-type,and the study to rural domestic sewage on the zeolit is at an eary stage. This paper mainly studied five aspects about Jinyun zeolit:first,the basic performance of Organic,ammonia-nitrogen and phosphorus removal by Jinyun zeolit.Second,the choices of suitable method to make zeolit modified and the effect of Organic removal,ammonia-nitrogen removal and phosphorus removal by the modified zeolit.Third,according to the sorption performance of Jinyun clinoptilolite, the modified zeolite is prepared. In this paper, the suitable modified conditions and effects of modified zeolite to remove organic, nitrogen and phosphorus are researched. Forth, use the optimum modified zeolite as the carrier to fix the advantage degradation bacterium bred and domesticated from rural domestic sewage, and research the effects of zeolite immobilized cells to remove organic, nitrogen and phosphorus in rural domestic sewage and the influence of relevant factors in the removal of organic, nitrogen and phosphorus. The experiment results were as follows:Rusults showed that the cation (NH₄⁺) exchange capacity of the Jinyun zeolit was 143mmol/100g.The results indicate that process of Organic and phosphorus was fit for the formula of Langmuir,the process of ammonia-nitrogen was fit for the formula of Freundlich.Organic, ammonia-nitrogen and phosphorus removal from rural domestic sewage by natural clinoptilolite, collected from Jinyun, Zhejiang province,was examined by batch-type methods.The effect of the dosage, contact time,particle size and pH on the removing Organic,ammonia-nitrogen and phosphorus by zeolite was investigated. 350℃,450℃,550℃,Sodium chloride, potassium chloride and calcium chloridewere adopted tomodify the natural zeolite. Results show that the optimal process of removing Organic should be observed in the conditions of zeolite 20g/l,contact time 8h,36-65 mesh,pH6.0-7.5, the activation temperature 550℃and the 2.0mol/l Ca²⁺ solution,which can remove Organic from rural domestic sewage with efficiency of 64.71%. The optimal process of removing ammonia-nitrogen should be observed in the conditions of zeolite 20g/l,contact time 120min,36-65 mesh,pH3.35-8.32, the activation temperature 450℃and the 0.5mol/l Na⁺ solution,which can remove ammonia-nitrogen from rural domestic sewage with efficiency of 99.33%.The optimal process of removing phosphorus should be observed in the conditions of zeolite 10g/l,contact time 120min,36-65 mesh,pH5-11, the activation temperature 550℃and the 0.2mol/l Ca²⁺ solution,which can remove phosphorus from rural domestic sewage with efficiency of 73.74%.The SHJ-1 screened out by breeding and domesticating can efficiently retrograde the rural domestic sewage. Under the liquid shaking culture for 16h, the SHJ-1 can reach to a maximum propagation. The optimum growth conditions for SHJ-1 are temperature of 30℃-35℃, pH = 7-8. Under the optimum conditions and inoculation of per 100 ml wastewater added 2.0 ml bacterial solution(bacteria suspension concentration is 10⁸ /ml), the removal rate of organic, nitrogen and phosphorus are respectively 37.85%,80.08% and 36.62%.Comparing with zeolite, dissociative bacteria and zeolite immobilized cells in rural domestic sewage treatment, the way of settled thalli growth on carrier is feasible. Experiments shows that zeolite immobilized cells has the best effects, the solidify technology can maintain the optimal performance of reduce pollution and also exerts the activity of dominant bacteria to remove organic, nitrogen and phosphorus.Zeolite immobilized cells removing organic, nitrogen and phosphorus depends on the temperature, pH value , dosage and contact time. Results show that the optimal process of removing Organic should be observed in the conditions of I-type zeolite 20g/l, the temperature 30℃, pH6, contact time 8h,with efficiency of 72.41%; the optimal process of removing ammonia-nitrogen should be observed in the conditions of II -type zeolite 15g/l, the temperature 30℃, pH8, contact time 60min,with efficiency of 99.72%;the optimal process of removing phosphorus should be observed in the conditions of III-type zeolite 15g/l, the temperature 30℃, pH8, contact time 60min,with efficiency of 89.90%.