Performance of Conventional Wastewater Treatment systems in the Treatment of Textile Effluent at Hawassa Industrial Park

Abstract

The textile industry is one of the oldest industries in the world and is a high-income-generating industry for developing countries. There is a significant link between the environment and the textile industry. A great deal of damage can occur to the environment from the textile industry, and a major threat to the environment is the discharge of untreated toxic wastewater into the water bodies, which can cause several damages to aquatic ecosystems. Similar problem has been observed at HIP wastewater treatment plant, which high concentrations of toxic substances being discharged to Lake Hawassa after passing through treatment processes and affecting aquatic life .The main objectives of this research were to evaluate the performance of the textile wastewater treatment plant of Hawassa Industrial Park based on select physico chemical parameters. The wastewater samples were collected from six units of the treatment process (receiving chamber, equalization tank, primary clarifier, aeration tank, secondary clarifier, and clear water storage tank) by grab sampling methods. Physico-chemical main parameters (pH, TSS, TDS, color, EC, turbidity, COD, BOD5, total hardness, total alkalinity, heavy metals, oil and grease laboratory analysis were conducted for two months from February 25, 2023 to April 25, 2023 at the Hawassa Industrial Park wastewater treatment plant. Sample analysis methods employed were volumetric analysis and microanalysis according to the procedures of standard water and wastewater analysis. The overall performance of the treatment plant with respect to pH, EC, color, and TDS were found to be 16%, 20%, 69%, and 19.77%, respectively, and turbidity, TSS, COD, BOD, total alkalinity, total hardness, and oil and grease were found to be 94%, 84%, 81.8%, 83.9%, 75.56%, 34.79%, and 91.4%, respectively. The removal efficiency of the thirteen heavy metals examined is 10% (B), 52.85% (Zn), 34.21% (Cd), 13.74% (Hg), 90.38% (Fe), 95.84% (Mn), 7.62% (Se), 12.26% (Pb), and 0% (Cu, Co, Ni, Cr, and As). The results revealed that the wastewater treatment plant has good performance to reduce turbidity (94%), O&G (91.4%), TSS (84%), BOD (83.9%), COD (81.8%), and total alkalinity (75.56%), whereas poor removal performance observed in pH (16%), EC (20%), TDS (19.77%), total hardness (34.79%), and color (69%). Confirmed the need of improvement in the current performance of the treatment plant.