摘要：
Based on the principle of hydraulics,an effective equipment of hydrodynamic cavitation is designed and built in this paper.The orifice plates with various geometry size were used as hydrodynamic cavitation generator to study the relation ship between many factor,such as,inlet pressure,discharge,flow speed in orifice,and the cavitation number.Analysis of water flow cavitation status for the experimental unit,this device can produce cavitation phenomenon.The methylene blue and spectrophotometer method can capture the free radicals generated successfully.This is an effective way to measuring the free radicals quantitatively in cavitation,moreover it is easy to fulfill.The intensity of cavitation increases with reduction in the cavitation number.By analyzing the influence of cavitation number on concentrations of center dot OH.It would be strength of hydrodynamic cavitation.The effect of operating parameters,such as inlet press,low speed in orifice and optimum the structure of hydrodynamic cavitation,best condition of the hydrodynamic cavitation is the inlet press,flow speed in orifice 14 m/s, beta 0.07.
摘要：
A modified peat was prepared by using nitrate and natural peat from Yiyang city in Hunan Province. The adsorption properties of the nitrifying peat for Methylene blue was investigated in aqueous solution. The effect of the adsorbent dosage, time and the initial concentration of methylene blue on the adsorption capability was discussed. The result showed that time and the adsorbent dosage had greater influence on the adsorption of Methylene blue, the adsorption of Methylene blue by Nitrifying peat was a rapid process, and in 20 min in the adsorption rate reached more and 60%, the adsorption amount was approximately proportional to the initial concentration( 20-100 mg /L). Langmuir and Freundlich isotherms were used to fit the equilibrium data, and it was found that the adsorption isotherm followed the Langmuir model.
摘要：
The dewatering and mineralization of sludge in the constructed reed bed was investigated in this study.The sludge from the secondary sedimentation tank is from in the wastewater treatment plant in Yiyang city,Hunan province.Anaerobic pond and oxidation ditch biological treatment processes is accepted there.The performance of the system was monitored for one year. Total Solids (TS), Volatile Solids(VS), Chemical Oxygen Demand, nutrients (TKN) and Total Phosphorus(TP), heavy metals in the sludge were analysed.The removal rate of COD,NH4-N,and TP of the percolated fluid for the first cycle was also monitored. TS content reached 36.5% for the surface layer and 37.8% for the bottom layer at the end of the examination period.Sludge stabilization in the bed was also observed(VS content decreased to 31.3% and 13.4% respectively for the surface and bottom layer).Concentration of nutrients of the sludge accumulated in the bed also decreased. The heavy metal concentration meets the European Union standards for heavy metals in case of agricultural disposal of the treated sludge.
