ساخت و ارزيابي بيوفيلتر چند مرحله اي به منظور تصفيه پساب هاي شهري

چكيده انگليسي :

Development and Evaluation of a Multi Stage Biofilter for Municipal Wastewater Treatment Sharife Karimi sharife karimi@ag iut ac ir January 22 2014 Department of Agricultural Machinery Engineering Isfahan University of Technology IUT Isfahan 84156 8311 Iran Language FarsiDegree M ScSeyed Jalil Razavi jrazavi@ cc iut ac irAbstractThe depletion of underground water resources and increase in population growth has forced societiestoward the application of non conventional water resources The use of municipal wastewater not onlyprovides water necessary for landscape and athletic fields turf irrigation and industrial complexes waterneeds it also prevents numerous environmental problems caused by the sewage systems in metropolitansand their suburban areas Biological wastewater treatment system is recognized as an effective method ofreducing nitrate salts and mineral soluble materials in wastewater In this method the process ofdenitrification takes place in biofilters containing absorbent material Absorbent material selected in thisstudy consisted of sand wood chips sugarcane tops and leaves wheat straw and zeolite each separatelyin 4 biofilter cylinders and also in sequential arrangements of top down layers in another four cylindersand lastly a complete mixture of the four material in one cylinder Sand filters were used to absorbsuspended material in the wastewater before entering the biofilters The aim of this study was to evaluatethe effect of different organic and inorganic adsorbents singularly and in combination with each other onreducing and eliminating pollutants The study of the trend in changes in nitrate concentrations over atime period of 8 weeks revealed significant differences between the type of filters and experiments steps p 0 05 The maximum nitrate removal rate during the period of testing of filters was for zeolite with45 51 at a pH level of 7 26 the lowest absorption rate was observed for the sand filter with 8 85 at apH level of 7 84 Wood chips sugarcane tops and leaves and wheat straw showed a reduction in nitratewith 41 16 43 04 and 43 04 at pH levels of 7 60 6 83 and 6 77 respectively The rate of nitrateabsorption for sequential layers of wheat straw wood chips sugarcane zeolite wood chips sugarcane zeolite wheat straw sugarcane zeolite wheat straw wood chips and zeolite wheat straw wood chips sugarcane were 42 80 44 33 40 29 43 44 percent which indicate higher absorption compared to some ofthe main treatments in this study Maximum electrical conductivity and total dissolved solids wereobserved for the first week after the operation of the biofiltration system was initialized Percentagechanges in electrical conductivity and total dissolved solids content increased from the third week of theexperiments meaning that over the time the amount of salt and water solubles further decrease Highestreduction in salinity and total dissolved solids was observed in the sand filter Considering changes intemperature and retention time in each filter maximum absorption rate was achieved in zeolite filter withan optimum retention time of 1 32 hours at 12 C Keywords wastewater treatment biological filtration wood chips sugarcane wheatstraw zeolite

كريمي، شريفه

ساخت و ارزيابي بيوفيلتر چند مرحله اي به منظور تصفيه پساب هاي شهري

پساب , فيلتراسيون بيولوژيكي , تراشه چوب , نيشكر , كاه گندم , زئوليت