Seasonal movement of trace-element discharge in a typical south-Indian suburban community

• Published in: Water science and technology Vol. 77; no. 3-4; pp. 1035 - 1047
• Main Authors: Joshua, Derrick Ian, Abeykoon, Sumith, Watanabe, Izumi, Paszek, Lucyna, Balakrishna, Keshava, Akiba, Masato, Guruge, Keerthi Siri
• Format: Journal Article
• Language: English
• Published: England IWA Publishing 01.02.2018
• Subjects: Activated sludge; Anthropogenic factors; Drinking water; Effluents; Environmental Monitoring; Heavy metal content; Hospitals; India; Inlets (waterways); Irrigation; Kidney diseases; Manganese; Metals, Heavy - analysis; Monsoons; Nickel; Pollution; Removal; Rivers; Seasons; Sewage; Sewage treatment; Sewage treatment plants; Silver; Sludge; Suburban areas; Trace elements; Trace metals; Waste Disposal, Fluid; Waste Water - analysis; Wastewater; Wastewater treatment; Wastewater treatment plants; Water Pollutants, Chemical - analysis; Water treatment; Wind; Arabian Sea; United States > US; Sri Lanka; India
• ISSN: 0273-1223; 1996-9732
• DOI: 10.2166/wst.2017.618

Four conventional activated sludge sewage treatment plants (STPs) in Southern India were chosen to investigate the occurrence of major ions and trace metals in dissolved fraction of the wastewater. Samples were collected from inlet and outlet of STPs during the pre-monsoon and monsoon seasons. Except for a few elements (Mn, Mo and Ni), the concentrations of the rest increased at the outlet of STPs, suggesting that there is an addition of these elements during the treatment process. The increase in concentrations at the STP outlet ranged from 1.25 times for Mn to 3,254 times for Ag during the pre-monsoon. In the monsoon, the increase ranged from 1.75 (Fe) to 1,510 (Ag). This suggests that there is a substantial anthropogenic input of these elements as they pass through the treatment process. Removal rates of elements in STPs also varied. 59% of Mn was removed during the treatment process during pre-monsoon as compared to 67% removal during monsoon.