Feasibility of an innovative integrated process of simultaneous desulfurization and denitrification

Journal of Harbin Institute of Technology ( New Series)，Vol. 15, No. 1, 2008measurement by gas chromatography suggests no hydro-1800gen sulfide (H2S) exists.Fig. 4 demonstrated that the amount of sulfate and140080 &sulfide ( described by sulfate ) in effluent is much high-1000p50 旨er than the influent sulfate, which indicated that cer-tain amount of sulfate was consumed in other ways. Atthe same time, some indiscerptible primrose yellowparticles appeared in effluent, which has been deter-)00 x'mined as elemental sulfur by hexahydropyridine. This5 10phenomenon proved that there must be some amount ofsulfate converted into elemental sulfur, and the processof De-sulfurization and De-nitrification appeared in the_o-oulfate concenration in efulent- 古sultate removal eficlencysulfde concentration in eflufentreactor. In addition ，author considers that there( denoated in sulfate)might be some denitrifying bacteria besidesFig.3 The removal efficiency of sulfate and nitrate in an-Thiobacillus denitrificans under such an anaerobicaerobic expanding-bed reactororder to testify these presume， sulfurconversions analysis in the reactor was presented by au-thor, which could be shown in Fig. 5.口Influent sulfate●Efluent sulfate口Efluent sulfate600123 456789 101112131415161718192021 2224 25 26 2728 29 30 31 32 3334Fig.4 Measurement of SOx in effluent一Elemental sulfur produced (aX) 一> over oxidized sulfate-Sufde reduced (X/3)Influentsulfate (M)-Sulfde left[1/3-a)X]Sulfate left (M-X)Note: It is presume that influent sulfate( SO42 ~ )concentration is M mg/L, ifX mg/L sulfate was reduced by sulfate-reducing bacteria( SRB) , there wasX/3 mg/L sulfide (S-- ) produced, and (M- X) mg/L sulfate was left. If there was aX mg/L sulfide ( involved in the produced X/3 mg/L sulfide) wasoxidized by Thiobacillus denitificans, aX mg/L elemental sulfur (S0 ) would produced, and(1/3- a) X mg/L sulfide would be left. If there was Y mg/L gulfde ( involved in the aX mg/L sulfide oxidized by Thiobacillus denirificans) was over oxidized according to Eq. (2), 3Y mg/L sulfate would be pro-Fig. 5 Sulfur conversions in the reactorAccording to Fig. 5, we could draw the followingp(S,) = [M - (M -X +3Y) - 3bX +3Y]/3 (5)calculation equation :The concentration of sulfate in effluent :The concentration of sulfide in effluent :p(NO3~) = p( NO3~ )( in influence) - 31p(S~) = (1/3-a) X(3)40aX - 93/40YThe concentration of sulfate in effluent:ia, b，Xp(SO42-) = M-X +3Y(4)and Y, three samples were obtained at the 7“day, theThe concentration of elemental sulfur in effluent:15* day, and the 28 day. The detail performance in-MYH中国模化吉Joumal of Harbin Institute of Technology (New Series)，Vol. 15, No. 1, 2008further demonstratedthat the simultaneoussulfateandfunctional bacteria populations.nitrogen removal was feasible in anaerobic expandReferences :sludge bed.[1] APHA. Standards Methods for the Examination of Water3 Conclusion and Suggestionsand W astewater. W ashington: American Public Health,1995.[2] Buisman CJ N, Bert C, Ijspeert P, et al. Optimization ofsulfur producation in a biotechnological sulfide-removingsynthesized high strength sulfate and nitrate wastewaterreactior. Biotechnology and Bioengineering, 1990, 38(2):treatment. Sulfate removal rate was above 85% and ni-trate removal rate approached 100% at the steady oper-[3] DengL W, Tang Y. The mechanism and progress of bio-ation stage, and sulfur was observed in effluent. Ilogical desulfurization. Shanghai Environmental Science,might be drawn a conclusion that integrated simultane-1998, 12(5): 35 -39.ous sulfate and nitrogen removal process was feasible[4] Wang AJ, Du D Z, Ren N Q. A .effective way of sulfideremoval and sulfur reclamation. Joumal of Environmentalaccording to sulfur and nitrogen balance and electron e-Science and Health ( A), 2005, 40( 10) :885 -892.quilibrium.[5] Wang X, Ren N, Liu G. Development of fast detection mo-Although the feasibility of integrated simultaneousethod for sulfide in acidogenic sulfate-reducing reactor u-desulfurization and denitrification process was illustra-sing sulfur ion selective electrode. Journal of Harbin Insti-ted in this study by experiment observation and mathe-tute of Technology, 2004, 36(6): 729 -731.matical inference ，quantification for the simultaneous[6] ZuoJ E, Yuan L, HuJ C, et al. The process of sulfide ox-sulfate and nitrogen removal procedure should be fur-idation using colorless sulfur bacteria. Environmental Sci-ther investigated by means of dynamics diagnosis on theence, 1995, 16(6): 7 -10..17●MYH中国集化工