An Laboratory Research On The Hydrodynamic Parameter For Artificial Filtration Medium

Wastewater land treatment system is an effective way in improving ecological environment and solving present water shortage problem, for its low cost, low investment, better wastewater treatment result and practicability of reclaiming treated water. The filter media in Wastewater land treatment system is artificial or semi-artificial porous media. The adsorption, transportation and distribution of pollutants in Wastewater land treatment system can be controlled by selecting porous media of different particle size and bulk density according to the result of wastewater treatment. Hydrodynamic parameters are key points on researching wastewater solution's transporting and transformation in land treatment system. The transportation and transformation rules of COD in artificial filter media is carried out in this paper by discussing the hydro-dynamical process and parameter change rules of COD transportation in sand of different particle size and bulk density in different situations. It provides scientific basis for designing and improving wastewater treatment.The experiment on filter coefficient indicates that: the filter coefficient respectively shows power, indexing relationship with particle size, temperature and shows negative coefficient with bulk density. Filter coefficient increases as particle size, temperature increase, the solute in sand column with same particle size but lower bulk density permeate more easily.The solute transport experiment shows that: the particle size has a second-order correlation with retard parameter R; the dispersion increase as particle size increase; retard parameter and dispersion correlates with temperature and bulk density positively. When the temperature vary from 21℃to 31℃,the temperature's effect on solute transport become weaker. The static COD degradation experiment shows that: the COD degradation rate with 1.0-2.0mm particle size is the highest, and the COD degradation rate correlates with bulk density positively; COD degradation equation is calculated. The micro-biology has a higher COD degradation ability at 21℃.