The impact of treated wastewater irrigation on strawberry development, fruit quality parameters, and microbial and chemical contaminant transfer: A health risk assessment

Abstract

The reuse of treated wastewater (TWW) in agriculture is an important alternative technology for reducing freshwater demand and improving soil physicochemical and biological properties. According to the Jordanian national water policy for 2023–2040, freshwater allocated for irrigation in Jordan's agriculture will be decreased and replaced with TWW. The purpose of this study was to investigate how irrigation with TWW influenced strawberry performance as a model for annual plants, namely, the impact on soil, plants, productivity, heavy metals and microbial contamination. Strawberry plants were irrigated with TWW, surface water (SW), and blended water (BW), as contrasted to domestic tap water (DW). Irrigation with TWW, SW, and BW raised the electrical conductivity, total organic compounds%, total nitrogen%, P, and K in the substrate; the rise in salinity, which is one of the most important abiotic stresses, was related to Cl buildup in the substrates, which has a detrimental influence on plant growth, development, and productivity. The heavy metal hazard index values in strawberry fruits were less than one in all treatments, suggesting that the heavy metal level in strawberry fruits did not exceed the requirement for health protection from serious risk. However, microbial contamination by fecal bacteria such as Escherichia coli and Enterococci spp. and human pathogens such as Pseudomonas aeruginosa, Salmonella spp., and Staphylococcus spp. increased by TWW irrigation, for example E. coli population increased from 1.8 × 102 in DW-irrigated fruits to 2.8 × 103 colony forming unit per gram in TWW-irrigated fruits, which may pose health risks. Accordingly, it is possible to conclude that TWW, SW, and BW can be used to irrigate strawberries, but it must be washed before consumption.