The Mechanism And Efficiency Of Nitrogen Removal Of Domestic Wastewater By Land Zoology Treatment System

A new approach--of Under-Ground-ditch-pattern soil zoologytreatment system is proposed for the enhanced of polluted water. N removal effects and mechanism of Under-Ground-ditch-pattern soil zoology treatment system is concerned in this paper. Study in this paper include filtration of the soil fillings and the plants which adopted to the condition of guizhou; start-up the pilot plant of Under ground-ditch-patter soil zoology treatment system; the influence of circulate parameters for the removal rate of N; indagation microbes in the pilot plant; experiments for nitrification/denitrification processes; mathematics simulation the rules of nitrogen translation and movement.The results demonstrate that the filtrated soil fillings which mainlyconfected by yellow clay--the typical soil in guizhou and plants suchas Canna, Taro, Calamus and Rock Bean Bine can effectively decrease the concentration of contaminations.It takes about 60 days to complete the pilot plant start-up under the temperature of 0-5℃ without seed sludge or sewage. This paper indicates N removal effects of the pilot plant influenced by different temperature, C/N and HRT. Lower temperature in winter is not main hindrance to N removal effects, the best HRT of the pilot plant is 6.7h. The experiment results showed that average removal rates of NH+4-N and TN were 87.78% and 74.11%, with average effluent concentrations of NHVN, TN being 14.48mg/L, 32.84mg/L respectively, which met the standard for water reuse issued by the Ministry of Construction of China.Nitrogen transformation bacteria analysis revealed that there were abundant nitrogen transformation bacteria in the pilot system. 103~106cfu/g (soil) , 103~106MPN/g (soil) , 104~106 MPN/g (soil) , 103~106 MPN/g (soil) , were obtained respectively for ammonifying bacteria, nitrite bacteria, nitrate bacteria, denitrifying bacteria. Nitrogen in the influent was mainly eliminated through biological removal via nitrification/denitrification processes. How to improve nitrification performance through change of soil-water-animalcule-plant environment was the key to enhance N removal rate. The measurement results of ORP in the filled soil showed that soil property satisfied the ox-red condition. Under the lab condition, the nitrification dynamics and its influence factors of manual soil such as F.C. , temperature and the organic material are studied, the denitrification rate and kinetics are measured also.It showed that Under ground-ditch-patter soil zoology treatment system still has potential in disposal loadings.