Assessment of chemical and bacteriological status of treated wastewater of the Baraki WWTP (Algeria) for agricultural purposes

Abstract

Due to its geographical location in the arid and semi-arid zone, Algeria is suffering from water stress amplified by the effects of climate change. For these reasons, this study was conducted to evaluate the suitability for agricultural reuse of treated wastewater of Baraki WWTP. The quality of agricultural reuse is related to the physico-chemical parameters and indicators of water quality. The bacteriological characteristics including total and fecal coliforms, fecal Enterococci, Salmonella spp. and Staphylococci spp. were also considered. The results revealed that sodium adsorption ratio (SAR) and soluble sodium percentage (SSP) values were excellent for irrigation. Wilcox diagram showed that most of the samples fall in the field of C3-S1 indicating high salinity and low sodium water. The physico-chemical results indicated that most of the parameters are in conformity with standards except ammonia NH4+ and total nitrogen that are higher than the permissible limit of USEPA and FAO. The average concentrations of heavy metals are low compared to the FAO recommendations. However, the bacteriological analyses confirmed the existence of germs indicating a fecal contamination exceeding the WHO regulations but an absence of pathogenic germs. Hence, the disinfection of this water and adequate treatment is needed before its use for agricultural purposes.