A traditional sequencing batch reactor （SBR） and two intermittently aerated sequencing batch reactors （IASBRs） were parallelly operated for treating digested piggery wastewater. Their microbial communities were an...A traditional sequencing batch reactor （SBR） and two intermittently aerated sequencing batch reactors （IASBRs） were parallelly operated for treating digested piggery wastewater. Their microbial communities were analyzed, and the nitrogen removal performance was compared during the long term run. IASBRs demonstrated higher removal rates of total nitrogen （TN） and ammonium nitrogen （NH4＋ -N） than the SBR, and also demonstrated higher resistance against TN shock load. It was found that the more switch times between aerobic/anoxic in an IASBR, the higher the removal rates of TN and NH4＋ N. All the reactors were predominated by Thauera, Nitrosomonas and Nitrobacter, which were considered to be species of denitrifiers, ammonium oxidizing bacteria （AOB） and nitrite oxidizing bacteria （NOB）, respectively. However, the abundance and diversity was of great difference. Compared with SBR, IASBRs achieved higher abundance of denitrification related bacteria. IASBR 1# with four aerobic/anoxic switch times was detected with 25.63% of Thauera, higher than that in IASBR 2# with two aerobic/anoxic switch times （l 1.57% of Thauera）, and much higher than that in the SBR （only 6.19% of Thauera）. IASBR 2# had the highest percentage of AOB, while 1ASBR 1# had the lowest percentage. The denitrifiers abundance was significantly positive correlated with the TN removal rate. However, the NH4＋ N removal rate showed no significant correlation with the AOB abundance, but might relate to the AOB activity which was influenced by the average free ammonium （FA） concentration. Nitrobacter was the only NOB genus detectable in all reactors, and were less than 0.03%.展开更多
A new Arthrospira strain named Arthrospira sp.ZJWST-S1 was isolated from a local digested piggery wastewater(DPW)storage pool in Jiaxing City,Zhejiang Province,China.It possessed good stain resistance against contamin...A new Arthrospira strain named Arthrospira sp.ZJWST-S1 was isolated from a local digested piggery wastewater(DPW)storage pool in Jiaxing City,Zhejiang Province,China.It possessed good stain resistance against contaminants in DPW,which was pretreated with a membrane bioreactor(MBR).The strain was identified as Arthrospira platensis(A.platensis)based on its morphological characteristics and the 16S rDNA sequencing analysis.The effect of chrominance on growth of A.platensis ZJWST-S1 was investigated in a field raceway pond filled with MBR effluent or MBR effluent decolorized with ozonation.After ozonation,the chrominance of MBR effluent was decreased from 700 mg Pt/L to 150 mg Pt/L.Two runs of cultivation showed that A.platensis ZJWST-S1 grew faster in the ozone decolorized MBR effluent,the averaged biomass concentration being 0.907 g/L after 10 days of cultivation,close to that in a Zarrouk medium(0.969 g/L).By comparison,the biomass grew much slower in the non-decolorized MBR effluent(0.624 g/L).The pollutant removal was also benefited from the accelerative growth of A.platensis ZJWST-S1 in the decolorized MBR effluent.Almost all ammonium,61.2%of nitrate and 68.1%of phosphate were removed by the A.platensis ZJWST-S1 in the decolorized MBR effluent,much higher than the corresponding values of almost all ammonium,25.4%of nitrate and 36.5%of phosphate in the MBR effluent.Furthermore,the Arthrospira biomass harvested from the ozone decolorized MBR effluent after 10 d cultivation was with crude protein content of 59.1%±3.5%in dry algae powder.The content of Pb,As,Cd and Hg in biomass was also low enough to meet the Chinese Arthrospira Standard for Animal Feed(GB/T 17243-1998).This study showed that the new strain A.platensis ZJWST-S1 possessed potential to be used for producing animal feed and simultaneous removal of nitrogen and phosphorus in DPW.展开更多
An intermittently aerated sequencing batch reactor （IASBR） and a traditional sequencing batch reactor （SBR） were parallelly constructed to treat digested piggery wastewater, which was in high NH4＋ -N concentratio...An intermittently aerated sequencing batch reactor （IASBR） and a traditional sequencing batch reactor （SBR） were parallelly constructed to treat digested piggery wastewater, which was in high NH4＋ -N concentration but in a low COD/TN ratio. Their pollutant removal perfonnance was compared under COD/TN ratios of 1.6-3.4 d and hydraulic retention times of 5 3 d. The results showed that the IASBR removed TN, NH4＋-N and TOC more efficiently than the SBR. The average removal rates of TN, NH4＋-N and TOC were 83.1%, 96.5%, and 89.0%, respectively, in the IASBR, significantly higher than the corresponding values of 74.8%, 82.0%, and 86.2%. in the SBR. Mass balance of organic carbon revealed that the higher TN removal in the IASBR might be attributed to its efficient utilization of the organic carbon for denitrification, since that 48.7%- 52.2% of COD was used for denitrification in the IASBR, higher than the corresponding proportion of 43.1%-47.4% in the SBR. A prc-anoxic process in the IASBR would enhance the ammonium oxidation while restrict the nitrite oxidation. Anoxic duration of 40-80 min should be beneficial for achieving stable nitritation.展开更多
文摘A traditional sequencing batch reactor （SBR） and two intermittently aerated sequencing batch reactors （IASBRs） were parallelly operated for treating digested piggery wastewater. Their microbial communities were analyzed, and the nitrogen removal performance was compared during the long term run. IASBRs demonstrated higher removal rates of total nitrogen （TN） and ammonium nitrogen （NH4＋ -N） than the SBR, and also demonstrated higher resistance against TN shock load. It was found that the more switch times between aerobic/anoxic in an IASBR, the higher the removal rates of TN and NH4＋ N. All the reactors were predominated by Thauera, Nitrosomonas and Nitrobacter, which were considered to be species of denitrifiers, ammonium oxidizing bacteria （AOB） and nitrite oxidizing bacteria （NOB）, respectively. However, the abundance and diversity was of great difference. Compared with SBR, IASBRs achieved higher abundance of denitrification related bacteria. IASBR 1# with four aerobic/anoxic switch times was detected with 25.63% of Thauera, higher than that in IASBR 2# with two aerobic/anoxic switch times （l 1.57% of Thauera）, and much higher than that in the SBR （only 6.19% of Thauera）. IASBR 2# had the highest percentage of AOB, while 1ASBR 1# had the lowest percentage. The denitrifiers abundance was significantly positive correlated with the TN removal rate. However, the NH4＋ N removal rate showed no significant correlation with the AOB abundance, but might relate to the AOB activity which was influenced by the average free ammonium （FA） concentration. Nitrobacter was the only NOB genus detectable in all reactors, and were less than 0.03%.
基金Zhejiang Provincial Key Research Project(2014C03022).
文摘A new Arthrospira strain named Arthrospira sp.ZJWST-S1 was isolated from a local digested piggery wastewater(DPW)storage pool in Jiaxing City,Zhejiang Province,China.It possessed good stain resistance against contaminants in DPW,which was pretreated with a membrane bioreactor(MBR).The strain was identified as Arthrospira platensis(A.platensis)based on its morphological characteristics and the 16S rDNA sequencing analysis.The effect of chrominance on growth of A.platensis ZJWST-S1 was investigated in a field raceway pond filled with MBR effluent or MBR effluent decolorized with ozonation.After ozonation,the chrominance of MBR effluent was decreased from 700 mg Pt/L to 150 mg Pt/L.Two runs of cultivation showed that A.platensis ZJWST-S1 grew faster in the ozone decolorized MBR effluent,the averaged biomass concentration being 0.907 g/L after 10 days of cultivation,close to that in a Zarrouk medium(0.969 g/L).By comparison,the biomass grew much slower in the non-decolorized MBR effluent(0.624 g/L).The pollutant removal was also benefited from the accelerative growth of A.platensis ZJWST-S1 in the decolorized MBR effluent.Almost all ammonium,61.2%of nitrate and 68.1%of phosphate were removed by the A.platensis ZJWST-S1 in the decolorized MBR effluent,much higher than the corresponding values of almost all ammonium,25.4%of nitrate and 36.5%of phosphate in the MBR effluent.Furthermore,the Arthrospira biomass harvested from the ozone decolorized MBR effluent after 10 d cultivation was with crude protein content of 59.1%±3.5%in dry algae powder.The content of Pb,As,Cd and Hg in biomass was also low enough to meet the Chinese Arthrospira Standard for Animal Feed(GB/T 17243-1998).This study showed that the new strain A.platensis ZJWST-S1 possessed potential to be used for producing animal feed and simultaneous removal of nitrogen and phosphorus in DPW.
文摘An intermittently aerated sequencing batch reactor （IASBR） and a traditional sequencing batch reactor （SBR） were parallelly constructed to treat digested piggery wastewater, which was in high NH4＋ -N concentration but in a low COD/TN ratio. Their pollutant removal perfonnance was compared under COD/TN ratios of 1.6-3.4 d and hydraulic retention times of 5 3 d. The results showed that the IASBR removed TN, NH4＋-N and TOC more efficiently than the SBR. The average removal rates of TN, NH4＋-N and TOC were 83.1%, 96.5%, and 89.0%, respectively, in the IASBR, significantly higher than the corresponding values of 74.8%, 82.0%, and 86.2%. in the SBR. Mass balance of organic carbon revealed that the higher TN removal in the IASBR might be attributed to its efficient utilization of the organic carbon for denitrification, since that 48.7%- 52.2% of COD was used for denitrification in the IASBR, higher than the corresponding proportion of 43.1%-47.4% in the SBR. A prc-anoxic process in the IASBR would enhance the ammonium oxidation while restrict the nitrite oxidation. Anoxic duration of 40-80 min should be beneficial for achieving stable nitritation.
