Pollution of Large, Subtropical Rivers-River Kabul, Khyber-Pakhtun Khwa Province, Pakistan) : Physico-Chemical Indicators

Abstract

Abstract.-Water quality in River Kabul was monitored to determine if indusatrial effluents and city sewage had a significant impact on it. Water samples were collected three times a year, two times in winter (low Q) and once during summer (high Q) for three years. Sampling was carried out along a section of River Kabul receiving untreated industrial effluents to assess the physico-chemical variables and was compared with upstream water from Warsak Dam being pristine. Factories discharge effluents having high organic pollutants load into the river which is evident from the high value (290.5, 280 mgO 2 /l for low Q and 295.7, 281.7 mgO 2 /l for high Q periods) of biological oxygen demand (BOD) in comparison with the National Environmental Quality Standard (NEQS) value of 80 mgO 2 /l set for this variable. The river water downstream of entry of industrial wastewater had total suspended solids, biological oxygen demand, NH 3 , Cl -and SO 4 2-17%, 8%, 58%, 42%, 17% and 148% higher than those in the upstream water during low Q (winter), whereas these variables were 6%, 100%, 286%, 25% and 132% higher than those in upstream water, respectively, during the high Q (summer) season. These raises concern over the long-term health of the River Kabul ecosystem