Removal of pollutants and pathogens by a simplified treatment scheme for municipal wastewater reuse in agriculture.
- Science of the Total Environment, 580, p.17-25, 2017 .
The availability of high quality water has become a constraint in several countries. Agriculture represents the main water user, therefore, wastewater reuse in this area could increase water availability for other needs. This research was aimed to provide a simplified scheme for treatment and reuse of municipal and domestic wastewater based on Sequencing Batch Biofilter Granular Reactors (SBBGRs). The activity was conducted at pilot-scale and particular attention was dedicated to the microbiological quality of treated wastewater to evaluate the risk associated to its reuse. The following microorganisms were monitored: Escherichia coli, Salmonella, Clostridium perfringens, somatic coliphages, adenovirus, enterovirus, Giardia lamblia and Cryptosporidium parvum. The possibility of SBBGR enhancement with sand filtration was also evaluated. The SBBGR removed > 90 per cent of suspended solids and chemical oxygen demand, and 80 per cent and 60 per cent of total nitrogen and phosphorous, respectively. SBBGR was also effective in removing microbial indicators, from 1 (for C. perfringens)up to 4 (for E. coli)log units of these microorganisms. In particular, the quality of SBBGR effluent was already compatible with the WHO criteria for reuse (E. coli ? 103 CFU/100 mL). Sand filtration had positive effects on plant effluent quality and the latter could even comply with more restrictive reuse criteria.