Study of the physico- chemical parameter of pulp and paper industry effluent

The pulp and paper industries (PPI) are one of the most resource-intensive and polluting sectors worldwide, generating large volumes of effluents with high concentrations of suspended solids, dissolved solids, and oxygen-demanding substances. This study evaluates the physicochemical characteristics of wastewater from a wood-based paper mill, focusing on effluents collected from the primary clarifier outlet (PCOE) and secondary clarifier outlet (SCOE). Parameters such as pH, total suspended solids (TSS), total dissolved solids (TDS), chemical oxygen demand (COD), and biological oxygen demand (BOD) were analyzed using standard methods. Results revealed that the PCOE exhibited alkaline pH (8.3–9.2) and significantly higher pollutant load (TSS: 230–300 mg/L, COD: 900–1100 mg/L, BOD: 300–450 mg/L) compared to the SCOE (TSS: 22–30 mg/L, COD: 320–380 mg/L, BOD: 35–50 mg/L). Secondary treatment was effective in reducing TSS by nearly 90% and lowering COD and BOD by threefold and tenfold, respectively. However, TDS levels remained high (1860–2150 mg/L), posing risks to water quality and potential ecological damage. The findings highlight the necessity for advanced treatment strategies beyond conventional clarifiers to achieve permissible effluent discharge limits and mitigate environmental impacts of the pulp and paper sector.