Study On Filtration Adsorption And Bioactive Carbon Technology In Bathing Wastewater Treatment

With the serious shortage of water resources and pollution,the problem of gray water reuse has been paid more and more attention.Large emissions,light pollution and easy-handling make bathing wastewater become the priority sources of raw water for wastewater reuse.What's more,bathing wastewater contains anionic surfactants?LAS?and other refractory organic matter,and direct emissions will cause great harm to the environment.So,bathing wastewater reuse treatment not only can alleviate the shortage of water resources in China,but can bring huge economic and social benefits.In this paper,the bathing wastewater samples from a university bathhouse was taken as the object of study.After investigating the water quality characteristics of water samples,the effects of different filter media on the adsorption of bathing wastewater were investigated using filtration and adsorption technology.The competitive adsorption characteristics of LAS and chemical oxygen demand?COD?on activated carbon were also investigated.Through the deep treatment of water samples using bio-activated carbon technology,the removal of pollution indicators and the impact of different factors on the treatment effect were explored,with a view to finding a way which can cost-effectively handle bathing wastewater,to meet the water quality standards for landscape environments.The main findings are as follows:1)Water quality characteristics were investigated.The results show that the water turbidity of bath waste is high,mainly including COD,LAS,NH4+-N,TP and other pollutants,and the indicators are not in line with the landscape environmental water quality standards.The quality and emission of bath water change significantly from different time of a day and different seasons.2)Effects of four kinds of filter materials on bathing wastewater were compared.The optimum filtration rate and filter height were determined by the dynamic filtration adsorption test device compared with the filter adsorption effect of zeolite,activated carbon,ceramsite and anthracite.Different filter on the removal of pollutants to show a certain degree of specificity,which is reflected in the following aspects.The effect of zeolite on turbidity and NH₄⁺-N treatment was obvious.The effect of activated carbon on turbidity,COD and LAS removal was better,and the effect of ceramsite on TP and NH4+-N removal was better.The effect of anthracite on the turbidity,TP removal is excellent.3)Competitive adsorption properties of LAS and COD were analyzed.Results show that the adsorption of LAS on activated carbon can be fitted by Langmuir,Freundlich adsorption isotherm equation and quasi-first and quasi-second adsorption kinetics model.The adsorption of COD can only be fitted by Langmuir adsorption isothermal equation and quasi-second adsorption dynamic model.LAS and COD have competitive adsorption on the surface of activated carbon,and the adsorption sites are not identical.The total adsorption capacity of activated carbon increases due to the competitive adsorption.The competitive adsorption thermodynamics process can be described by Langmuir and Freundlich adsorption isotherms,and the kinetic process can be fitted with a quasi-second-order adsorption kinetic model.4)Effects of bio-activated carbon on bathing wastewater were investigated by natural biofilm.Following conclusions are obtained from the experiment.The optimum flow rate of the reactor is 5.0 L/h,the height of the filter layer should be 140 cm,and the gas/water ratio should be set to 8:1.In the stable operation of the reactor,the treatment effect of COD,NH₄⁺-N LAS and TP reaches the water quality standard of landscape environment.The backwashing intensity of the reactor should be controlled at 0.5-0.6 L/?m²·s?,the expansion of the filter is about 30.0%,the backwash time should be 15 min and the backwash cycle should be controlled at 6-8 days.