The Study Of The Combined Three-chamber Anaerobic Reactor And Vertical Subsurface Flow Constructed Wetland Process For Rural Grey Wastewater Treatment

The combined three-chamber anaerobic reactor and vertical subsurface flow constructedwetland process was studied for the treatment of rural dispersed grey wastewater. This paperstudied the water quality, hydraulic loading and temperature on the operational effect of three-chamber anaerobic reactor; analyzed the impact of hydraulic retention time and temperatureon the operational effect of vertical subsurface flow constructed wetland; researched on thephosphorus adsorption of red soil; surveyed the effect of removing pollutants by thecombined three-chamber anaerobic reactor and vertical subsurface flow constructed wetlandprocess. The following results were obtained:1. The kitchen water consumption stabilized in9months. The washingwastewaterconsumption increasd from December to August and the summer consumptionwas significantly higher than winter consumption. The proportion of wastewater consumptionand kitchen water consumption increased in the nine months, changing in the proportion ofone to three. The concentration of COD_Cr、TN、TP in the grey water changed little with theseasons, the concentration of N_H4⁺-N was higher in summer than in winter.2. Langmuir isotherm equation fit better than Freudlich isotherm equation in red soilphosphorus adsorption isotherm. The saturated adsorption capacity of phosphorus can reach1.854m g/g when the temperature was30℃; The phosphorus adsorption quantity increasedrapidly with time in the initial period and approached to a constant level in the later period.When the initial concentration of phosphorus was higher than a certain value, the temperatureaffected affecting red soil phosphorus adsorption as main control factor. The influence of pHfrom6to9on phosphorus adsorption was not significant in the test sample system.3. The removal effect of N_H4⁺-N, TN and TP by the combined three-chamber anaerobicreactor was poor, the organic matter can be removed effectively by three-chamber anaerobicreactor. When the hydraulic retention time for constructed wetland system was36h, theremoval rate for COD_Crwas42.2%. Increasing the retention time was favorable to removal ofCOD_Cr; The removal effect in summer is far better than in winter; Wastewater quality had lesseffect on the removal rate of anaerobic reactor.4. The removal effect of COD_Cr, N_H4⁺-N, TN and TP by the vertical subsurface flowconstructed wetland was good. When the hydraulic retention time for constructed wetlandsystem was36h, the removal rate for COD_Cr, N_H4⁺-N, TN and TP was73.8%,77.3%,70.9%and78.7%successively. Increasing the retention time and the temperature was favorable toremoval of pollutant. 5. When the influent COD_Cr, N_H4⁺-N, TN and TP concentration was276.3³34.6,3.2¹5.8,13.2³7.4and1.5³.7mg/L respectively, the COD_Cr, N_H4⁺-N, TN and TP averageremoval efficiency was86.7%,76.3%,70.7%and76.8%accordingly under the operationconditions of the anaerobic reactor72h HRT and the vertical constructed wetland75h HRT.The effluent above-mentioned indexes average concentration was39.6mg/L,1.9mg/L,6.0mg/L and0.6mg/L respectively. The TP could meet the I-class B criteria and the COD_Cr,N_H4⁺-N, TN could meet the I-class A criteria （GB18918-2002）.