Performance Of Biological Filter With Adsorptive Media Treating Micro-polluted Source Water In Low Temperature

In recent years, urban drinking water source had widespread seasonal ammonia andorganic pollution problems in China, which showed that ammonia nitrogen and organicconcentration was too high in low temperature condition in winter, and the conventionaltreatment process can not guarantee the safety of drinking water supply. It was put forward touse the adsorptive materials as the filter media to build materialized adsorption and biologicaloxidation synergies biofilter to maximize the performance of the adsorption filter, in order tosolve the problem of high ammonium and organic in water treatment plant effluent under lowtemperature conditions in winter.The subject chose the Huaihe raw water with the seasonal heavy high-risk unstablepollution characteristic as the research object.Under the temperature of15°C, the results ofthe long-running small-scale, pilot-scale and demonstration projects of the biofilter wasanalysed,in order to explore Adsorptive Media Biological Filter(AMBF) removal of turbidity,ammonia, nitrite, nitrate, CODMn,UV254index in cryogenic oligotrophic conditions, at last itwas put forward to new technology for cryogenic oligotrophic water source treatment,providing the basis for waterworks transformation.The natural zeolite adsorption static test results showed that the zeolite has rapidadsorption, slow release characteristics;Discussing the zeolite adsorption ammonia nitrogenkinetics characteristic, it corresponded with Langmuir isothermal adsorption equation.The small-scale studies on zeolite and ceramic Biological Aerated Filter for analogcryogenic oligotrophic water source has shown that：Zeolite and ceramsite biological aeratedfilter was started successfully after16and18days respectively;The results showed that ZBAFto remove ammonia nitrogen and organic matter is better than Ceramsite biological aeratedfilter.When average water ammonia nitrogen concentration was5.02mg/L, the zeolite andceramsite aeration biological filter effluent ammonia nitrogen was1.19mg and1.81mg/Lrespectively, and the average removal rate was76.53%and65.07%;When water CODMnindex with a mean of3.79mg/L, the zeolite and ceramsite aeration biological filter effluentCODMnindex with a mean of2.59mg/L and2.79mg/L, the average removal rate was30.7% and25.18%. Compared with ceramsite biological aerated filter, ZBAF effluent was morestable, and has a better resistance performance for ammonia nitrogen shock loading.With a microscope observation of biological phase on the surface of the filter material,rotifers, worms and other creatures was found, which was shown that there was completebiological phase in the filter, and water quality was better. Temperature impact aerationbiological filter processing efficiency, the ability of ZBAF to adapt to low temperatureenvironment was better than that of ceramsite aeration biological filter. When the watertemperature was lower than5℃, zeolite and ceramsite aeration biological filter for ammonianitrogen removal rate decreased to30.93%and12.82%respectively, the removal rate ofCODMnindex dropped to12.11%and12.11%respectively. Appropriate hydraulic retentiontime (HRT) and air-water ratio had some influence on organic matter removal for ZBAF. Inthis experiment condition, the best HRT and air-water ratio of the BAF were30min and2:1.The pilot-scale studies on quartz sand biological filter treatment of huaihe river waterand ZBAF under the condition of low temperature has shown that: When the hydraulicloading was7.6m3/(m2·h), quartz sand biological filter effluent turbidity, ammonia nitrogenaverage was0.24NTU and0.38mg/L respectively, the average removal rate of84.28%and56.67%; ZBAF effluent turbidity, ammonia nitrogen average was0.26NTU and0.20mg/Lrespectively, the average removal rate of82.68%and70.92%; Two filter removal efficiencyof organic matter was bad, almost no removal effect of CODMnand UV254.When the hydraulic load was7.6m3/(m2·h), the activated carbon/quartz sand combinationbed process effluent turbidity, ammonia nitrogen, CODMn, UV254average was0.24NTU,0.38mg/L,2.92mg/L, and0.046cm-1, the average removal rate of84.28%,56.67%,7.53%and56.67%; Compared with the other three kinds of filter, zeolite/activated carbon combinationbed process of ammonia nitrogen, CODMnand UV254has better removal effect, effluent waterstability, meeting the national drinking water standard,and has a best resistance performancefor ammonia nitrogen and organic matter shock loading, So it chose zeolite/activated carbonfor waterworks demonstration project of the biological filter filter material.The condition of low temperature the zeolite/activated carbon filter material filterdemonstration project process has a better removal effect to turbidity, ammonia nitrogen,nitrite nitrogen and CODMnof huai river water; Effluent turbidity, ammonia nitrogen, nitrite and CODMnaverage was0.84NTU,0.13mg/L,2.33mg/L, the average removal rate of57.03%,76.74%,57.70%and76.74%; It showed good resistance performance for ammonianitrogen and organic matter shock loading, making the effluent water meet the nationaldrinking water standard.