Temporal trends in pre- and post-treatment sewage water and sludge quality at ludhiana sewage treatment plant

A study was conducted to assess the quality of untreated waste water (carrying untreated/partially treated domestic sewage and industrial effluents in it) of Ludhiana city supplied to Bhattian Sewage treatment plant (STP) through a narrow unlined channel (Buddha Nullah), and change in quality parameters after the treatment during different seasons of the year. The Buddha Nullha waste water analysis showed that quality parameters biological oxygen demand (BoD), chemical oxygen demand (CoD), total solids (TS), total dissolved solid (TDS) and total suspended solids (TSS) were higher than the maximum permissible limits (MPL), however, after its treatment at Bhattian all these parameters approached well with in their respective MPL and fit for irrigation. The heavy metal concentrations in untreated waste water (influent of Bhattian STP) showed variable trend during different months depending primarily on the industrial flow. The different heavy metals concentration such as chromium (Cr), nickel (Ni), decreased in the effluent of Bhattian STP. All heavy metals in the sewage sludge from the Bhattian STP got concentrated, but highly variable which corresponds with wastewater metal concentrations variability.