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 for agricultural reuse is related to the physicochemical parameters and indicators of water quality. The bacteriological characteristics including total and fecal coliforms, fecal enterococci, Salmonella spp. and Staphylococcus spp. were also considered. The results revealed that SAR and SSP values were excellent for irrigation. A Wilcox diagram showed that most of the samples fell in the field of C3-S1 indicating high salinity and low sodium water. The physicochemical results indicated that most of 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 with 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 an adequate treatment is needed before its use for agricultural purposes. HIGHLIGHTS Algeria is actually facing a water crisis, especially in the agricultural sector.; Reusing treated wastewater is an alternative for irrigation.; WWTP of Baraki which uses sand filtration is a good choice for study.; The physico-chemical and bacteriological quality of the treated wastewater is poor.; Disinfection treatment is necessary for the reuse of this treated wastewater.;

Keywords

• agricultural reuse
• bacteriological quality
• heavy metals
• irrigation
• physico-chemical characteristic
• treated wastewater