The Mechanism And Effect Study Of Dephosphorization Of Under-Ground-Ditch-Pattern Sewage Zoology Treatment System

The effect and mechanism of dephosphorization of Under-Ground-Ditch-Pattern sewage zoology treatment system were studied by auther in this paper.The design parameters with test system were confirmed on the base of the dynamic small examination. The system had ran for 21 months and 15400 datas were got. According to the experimental results, the system had a high dephosphorization rate which was 96.60%. The average concentration of the discharged water was 0.305mg/L. Furthermore the dephosphorization effect of this system wasn't effected by the different seasons. The first disposal bed acted primary action for dephosphorization in all disposal beds and its dephosphorization efficiency was 70.55%. The ratio of BOD5/TP and CODcr/TP didn't effect the dephosphorization effect for disposing the low concentration sewage. This system also had the ability of resisting water power and organic concussion load.The main substance for purifying polluted water is the fillings which dephosphorized the sewage through the function of adsorption and deposition. So that the phosphoric static and dynamic isothermal adsorption experiments were elected for studying the mechanism of adsorption. At the same time the dephosphorization effect of plants and biology were also studied simply. From the results the calcareous soil's maximal adsorbent phosphor quantity is 1430.1ug per gram soil, the purple soil's maximal adsorbent phosphor quantity is 1212.9ug per gram soil, the yellow soil's maximal adsorbent phosphor quantity is 1188.6ug per gram soil, the limestone's maximal adsorbent phosphor quantity is 1383.75ug per gram limestone and the Coal Ash maximal adsorbent phosphor quantity is 1154.04 ug per gram Coal Ash. The static isothermal adsorption curves anastomose well with three adsorption equations. The phosphoric adsorption process by the fillings has two phasesrone phase is a superficial adsorption process, the other phase is a farther transfer from surface to inside. The former progress is fast and the latter progress is slow. The dephosphorization rates of the fillingsadd fast with the time increasing before adsorption balance and add slow with the time increasing after adsorption balance. In the former reaction the quantity and velocity of absorption add fast with the time increasing and add slow in the latter reaction. The dynamic isothermal adsorption curves of five fillings also anastomose well with four kinetics equations within experimental phosphor solution concentrations (20~160ppm) . Some parameters that were concluded from kinetics equations can reflect the rule of adsorbing phosphor by the fillings. The apparent velocity constant (Ka) minishes and the relative diffuse coefficient (R) adds with experimental phosphor solution concentrations' increasing. The value of a, B from Elovich equation are dependable genes for judging adsorption reaction speed . The value of a is bigger and the adsorption velocity is faster .The value of B is bigger and the adsorption velocity is slower. From plants' potted experiment we could find the removed rates, of phosphor of the plants only occupied 0.35-238% in total removed rates of phosphor of the system . The interim distributing equipment of this system makes the system in the alternant anaerobic and aerobic state. The combined phosphorus bacterium in this system releases phosphor in anaerobic condition and absorb the organic substance of the sewage to get energy and reserve energy in the form of PHB in the thalli. In aerobic condition the combined phosphorus bacterium can decompose PHB to release energy and absorb phosphor. The whole process represent the synthesization and decomposability of PHB.