Qualitative Assessment of Wastewater of Shahid Hashemi Nezhad Gas Refinery and Adjacent Water Resources for Agricultural Use

To assess surface and groundwater quality in Shahid Hashemi Nezhad Gas Refinery region and effluent wastewaters from this industrial unit, 18 water and 5 wastewater samples were studied. Major anions and cations concentration ,pH, temperature, EC and TDS were measured in water and wastewater samples. Most of the water and wastewater samples were classified as brackish and saline water based on TDS content. Calculation of sodium hazard indices of irrigation water showed that only 30% of the water samples were in excellent range according to SAR, and the others have good, fair and poor quality. Among the wastewater samples only one sample showed excellent quality according to this parameter. Majority of water and wastewater samples had fair and unfavorable quality based on %Na and KR. Based on SAR and EC, only one wastewater sample had fair quality. RCS and RSCB showed suitable quality for the water and wastewater resources. Gibbs diagram, chloroalkaline index and binary diagrams showed evaporation, normal ion exchange and evaporative mineral dissolution (halite, gypsum and anhydrite) as effective factors on chemical composition of water resources.