An assessment of wastewater pollution, treatment efficiency and management in a semi-arid urban area of Pakistan


Mahfooz Y., Yasar A., Guijian L., Yousaf B. , Sohail M. T. , Khan S., ...More

DESALINATION AND WATER TREATMENT, vol.177, pp.167-175, 2020 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 177
  • Publication Date: 2020
  • Doi Number: 10.5004/dwt.2020.24949
  • Title of Journal : DESALINATION AND WATER TREATMENT
  • Page Numbers: pp.167-175

Abstract

Increased population growth, better living standards and improved economic activity put the upward burden on the world's inadequate water resources. A study was conducted to evaluate the quantity and quality of wastewater generated by industrial and municipal effluent and its treatment efficiency in a semi-arid city Faisalabad, Pakistan. Samples from industries (n = 60) and sewage water (n = 30) were collected and evaluated for different quality parameters. Physio-chemical including pH, total dissolved solids, suspended solids, biochemical oxygen demand (BOD) and chemical oxygen demand (COD), total coliform and heavy metals including arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), lead (Pb), nickel (Ni), and zinc (Zn) were analyzed. Emphasis was made on metal contamination by multivariate indexes including metal pollution index (MPI), degree of contamination (CD) and pollution load of drains. Aquatic macrophytes (Typha latifolia, Brachiaria mutica, Poa annua) were collected from anaerobic ponds of the Chokera wastewater plant. Results showed that all the parameters were higher than the upper limit of Punjab Environmental Quality Standards (PEQs) set by the Environmental Protection Agency (EPA) Pakistan. MPI was found high in textile industrial effluents (MPI > 1,000). The degree of contamination was very high than the maximum contamination level (>= 3) in industrial effluent (33.85) followed by sewage effluent (14.05). Pollution load was calculated which showed the high BOD (119.34 ton/d) and COD (376.41 ton/d) load in Pharang drain due to excessive discharge of industrial effluent. Treatment efficiency at Chokera wastewater ponds was higher (60%) in summers as compared to winters and through the phytoremediation process. Typha latifolia found a most suited plant with a high accumulation coefficient value for metals uptake. Parameters after treatment were still above the PEQs. So, these ponds need to be monitored quarterly for maintenance. The possible environmental benefits can be obtained by introducing such plants in wastewater drains and effluent treatment plants to enhance its efficiency. However, there should be a strict policy to be implemented for the control of industrial discharge by government agencies.