

@article {2676,
	title = {A case study of enteric virus removal and insights into the associated risk of water reuse for two wastewater treatment pond systems in Bolivia},
	journal = {Water Research},
	volume = {65},
	year = {2014},
	abstract = {Wastewater treatment ponds {(WTP)} are one of the most widespread treatment technologies in the world; however, the mechanisms and extent of enteric virus removal in these systems are poorly understood. Two {WTP} systems in Bolivia, with similar overall hydraulic retention times but different first stages of treatment, were analyzed for enteric virus removal. One system consisted of a facultative pond followed by two maturation ponds (three-pond system) and the other consisted of an upflow anaerobic sludge blanket {(UASB)} reactor followed by two maturation (polishing) ponds {(UASB-pond} system). Quantitative polymerase chain reaction with reverse transcription {(RT-qPCR)} was used to measure concentrations of norovirus, rotavirus, and pepper mild mottle virus, while cell culture methods were used to measure concentrations of~culturable enteroviruses {(EV).} Limited virus removal was observed with {RT-qPCR} in either system; however, the three-pond system removed culturable {EV} with greater efficiency than {the~UASB-pond} system. The majority of viruses were not associated with particles and only a small proportion was associated with particles larger than 180~μm; thus, it is unlikely that sedimentation is a major mechanism of virus removal. High concentrations of viruses were associated with particles between 0.45 and 180~μm in the {UASB} reactor effluent, but not in the facultative pond effluent. The association of viruses with this size class of particles may explain why only minimal virus removal was observed in the {UASB-pond} system. Quantitative microbial risk assessment of the treated effluent for reuse for restricted irrigation indicated that the three-pond system effluent requires an additional 1- to 2-log10 reduction of viruses to achieve the {WHO} health target of {\textless}10-4 disability-adjusted life years {(DALYs)} lost per person per year; however, the {UASB-pond} system effluent may require an additional 2.5- to 4.5-log10 reduction of viruses.},
	doi = {10.1016/j.watres.2014.07.032},
	url = {http://dx.doi.org/10.1016/j.watres.2014.07.032},
	author = {E.M. Symonds and M.E. Verbyla and J.O. Lukasik and R.C. Kafle and M. Breitbart and J.R. Mihelcic}
}
