| UASB reactor is widely used in the phenol wastewater treatment process,but some problems remain to be solved including long term startup time,difficult in sludge granulation and the lack of nitrogen and phosphorus for maintaining microbial growth.In this study,a comparative research on UASB with turfy soil,osmocote and struvite has carried out for the treatment of phenolic wastewater.The performance of the different reactors,sludge granulation process and impact resistant ability were investigated,and the microbial community structure was analyzed for each reactor in different period.The results showed that the maximum phenol load of UASB with turf soil was 1200 mg/L,and the COD removal rate was up to 98 %,which was 11 % higher than that of the control reactor.Turf soil can also strengthen the reactor’s resistance to high concentration of phenolic compounds,low temperature and high/low pH shocks.In addition,turf soil addition promoted the rapid formation of granular sludge,which was formed in 60 days,and the sludge showed better sedimentation performance and mechanical strength,more rich microbial community and higher levels of methanogens.Turfy soil has a rough surface structure and abundant pores,which are beneficial to the microbial adhesion,in addition,the humus can be used as a redox mediator to accelerate electron transfer rate and promote the anaerobic biodegradation of phenol.Osmocote and struvite are rich in nitrogen and phosphorus and has characteristic of slow-release capacity,can provide nutritions for microorganisms during the operational period.Compare to struvite,osmocote showed better ability on slow-release of nitrogen and phosphorus.The released nitrogen and phosphorus from osmocotewas in a suitable range,therefore,Osmocte was more suitable to use as support particles for UASB.The maximum phenol load of UASB with osmocote was 800 mg/L,and the COD removal rate was 90 %.Osmocote has a rough surface and abundant pore structure,which is conducive to the growth of microbe and accelerating granules formation.Osmocote can be used as a support particle with the ability of slow-releasing nitrogen and phosphorus to improve the UASB performance,and it has industrial application potential for the treatment of high-concentration organic wastewater. |
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