Technical Study On Humified Media Filter For Flushing Water Treatment

With the rapid development of our economy, rural urbanization level increased steadily, however, because of the regional concentration of rural living, and the popularity change of driking and lavatories, village sewage discharged after the pretreated of septic tank or directly discharged, which has become the main reason of the deterioration of water environment. View on the characteristics of rural sewage, many researchers have proposed a more economically feasible processing for the village or neighborhood, which is called distributed treatment, but the existing sewage distributed treatment technology mainly use villages or towns as the unit of sewage collected and treated, and the vast majority of technologies used to treat mixed sewage, also less consider the reuse of the treated tail water and other resource issues. In fact, after the change of drinking water and lavatories, farmers already have the hardware conditions of sub-quality streaming, as well as the demand of water reuse, and to achieve the solution of use household as unit for sub-quality sewage treatment is an integral part for rural domestic sewage series which has a positive significance for rural conservation and waste reduction. In response to this phenomenon, the proposed process of humified media filter for decentralized sewage treatment technology of sub-quality.Preliminary studies of HF technology are mostly use aged refuse as filler, which has a good effect of sewage treatment, low cost, simple operation, it is a kind of distributed processing for rural domestic sewage requirements of the new technology. But when use it to treat the sewage, there is the problem of the low removal rate of nitrogen, and the filler surface easy to plug, so when use HF to treat the flushing sewage, it need the study of process optimization and improvements of filler.Use peat as sorbent to study the effect of the initial concentration of adsorbate, adsorption time, temperature, pH on the adsorption of phosphorus and nitrogen, and as the basis of the study of the peat biofilter filler synergy adsorption and biodegradation. The results show that the optimum adsorption time of peat on phosphorus and ammonia is 0～15min, due to the adsorption rate is not only big, and the adsorption capacity is also optimal. The adsorption of peat on phosphorus is an exothermic reaction, increasing temperature is not conducive to phosphorus adsorption, adsorption characteristics Langmuir isotherm model; peat adsorption capacity of ammonia increases with temperature increases and then decreases, and the adsorption isotherm can be described by Freundlich isotherm. The effect of pH on the adsorption of peat on phosphorus is great, slightly alkaline is not conducive to the adsorption of peat on phosphorus; the adsorption of peat on ammonia increased with the increasing of pH, but when the pH reached 8, the peat dissolved organic carbon, which is not conducive to the stability of peat materials. When use peat as the adsorbent, in order to prevent the dissolution of humus, to control the pH not greater than 8.Use peat as surface filler for the HF of the pilot process, to study the treatment process performance and its influencing factors when use HF to treat flushing sewage. During summer run-time, with return water in 25%, the removal efficiency of the COD, NH4+-N, TN and TP reached 79.2%,79.7%,44.0% and 83.8% on average, during winter run-time, control return water in 50%, the removal efficiency of the COD, NH4+-N, TN and TP reached 48.7%,26.3%, 16.7% and 37.2% on average. The results are that, the good water holding capacity of peat is not conducive to water and air contact in the drying time, and peat have poor mechanical properties, easy to contraction and expansion. During winter with the hydraulic loading at 0.763m3/(m2·d), the device can run three months before blocking problem occurs, indicating that peat have better anti-clogging performance than the aged refuse.Based on previous studies, proposed that mix micro-organisms of aged refuse and peat, verify the work performance when the combination of the filler filled in HF. By compare with the different experiment columns with different ratio of peat and humus as fillers, it was found when the initial microbial biomass C of peat and aged refuse was 1:3, the treatment performance of experimental column was more stable, and when the initial microbial biomass C was 1:2, the permeability coefficient was maximum, the largest amount of microbial carbon,the best reoxygenation, and by the ratio of peat and aged refuse, which can effectively alleviate the dissolution of humus in the high pH (>8), when the initial microbial biomass C was 1:5, the dissolution of humus was least, it shows that by adding aged refuse, the rot microbial colonization waste and peat in synergy to improve the anti-clogging of filler and sewage treatment efficiency, and achieve the desired results, and got the best effect when the initial microbial biomass C of peat and aged refuse was 1:3.In the improvement of filler, it require further study of the optimal ratio of peat and aged refuse, to improver the anti-clogging performance of filler and sewage removal stability; at same time, after the improvement of filler, the mechanism of organic pollutants removal and nitrous compounds removal in HF should be further studied, to provide more room for the promotion and application of technology.