Along with the water environmental problems are becoming increasingly serious insmall towns and villages,the small town wastewater treatment in our country haveattracted much attention from more specialists.The choice of technology is the mostimportant content of the design and operation of the sewage plant,thus it’s urgent to find awastewater treatment process with low infrastructure and operation expenses,bettertreatment effects,easier operation and maintenance.what’s more,the process is suitable forthe application of small towns and villages.The pilot test in he-tou-dian town sewage treatment station in Lai xi DistrictQingdao city show that:The biological filtration wastewater land treatment process hasthe advantages of low energy,not to occupy a land area,blockage happening is not easilyand stable treatment effect in the small town wastewater treatment.After degraded bybiological filtration wastewater land treatment process,the TN concentration in effluent isbelow20mg/L TN removal rate of33.7%(20.39%-53.17%).The TP concentration ineffluent is below1mg/L(0.36mg/L) TP removal rate of67.53%(59.38%-81.87%). Thetreated water could reach the first grade class B discharging standard of ourcountry,especially effective in winter.Setting device for exposure to increase the nitration of NH3-N,we upgraded thebiological filtration wastewater land treatment process to the biological aerated filtrationwastewater land treatment process.By contrastive study on the removal efficiencybetween biological aerated filtration wastewater land treatment process and SBRprocess,compared with the traditional process, the basis datum have been provided forthe choice of technology in the design of wastewater treatment plant. The results indicatethat:In the same experiment environment carried out a study on the removal efficiency ofCOD in synthetic wastewater, the conditions of the COD concentration in effluentcould reach the first grade class B discharging standard of our country,the CODvoluemtric load of biological aerated filtration wastewater land treatment process(gravel packing) less than1.2kg COD·m-3·d-1(the COD concentration in effluent is below57mg/L);biological aerated filtration wastewater land treatment process(plastic filler)less than0.9kg COD·m-3·d-1(the COD concentration in effluent is below54mg/L);SBRprocess less than2.1kg COD·m-3·d-1(the COD concentration in effluent is below48mg/L). SBR process has a higher COD volumetric load than biological aeratedfiltration wastewater land treatment process,has such advantages as anti impulsion load,stable treating effect.Adoption of high ammonia-nitrogen wastewater(the COD concentration is155mg/L,the NH3-N concentration is35mg/L),biological aerated filtration wastewater landtreatment process has the better effluent qualityunder under low voluemtric loadcondition (when the COD concentration in effluent is below30mg/L,the NH3-Nconcentration in effluent is below3mg/L,the inlet COD volumetric load is low than0.24mg/m3·d, inlet NH3-N volumetric load low than0.046mg/m3·d)But,within thewhole range of experiment(inlet COD volumetric load0.128-0.64mg/m3·d, inlet NH3-Nvolumetric load0.027-0.137mg/m3·d),biological aerated filtration wastewater landtreatment process can get a better effluent quality which is unreachable for SBR byreduce the volumetric load,but along with the volumetric loads increased,SBR`s treatingeffect is more stable.It has been carried out a contrastive study on the aeration performance betweenbiological aerated filtration wastewater land treatment process and SBR process.Thepower efficiency of oxygen transfer in SBR reactor is0.3624kg·kw-1·h-1, in biologicalaerated filtration wastewater land treatment reactor is0.8774kg·kw-1·h-1.Higher power efficiency of oxygen transfer can meet the demand of dissolvedoxygen in reacter,in the same time, reduce the power consumption, save running cost.This is essential for promoting the sewage treatment of small towns is of greatsignificance. |