Characterization of physicochemical and bacteriological properties of Harar Brewery wastewater and its suitability for irrigation

Abstract

The brewery industry is known for consuming a significant amount of water during beer production and releasing large quantities of wastewater into the environment. The Harar Brewery factory generates a substantial amount of wastewater, which is utilized for irrigation. However, there have been no comprehensive scientific studies assessing the physicochemical and bacteriological properties of the wastewater in relation to its suitability for irrigation. Therefore, this study aimed to evaluate the physicochemical and bacteriological properties of the wastewater to determine its suitability for irrigation. The analytical procedures were conducted following the APHA procedure and the results were compared with national and international standards. Various parameters were investigated, including, temperature (25.01 °C), TDS (848.88 mg/L), TSS (256.67 mg/L), TS (1107.92 mg/L), pH (8.06), EC (1253.42 µS/cm), DO (3.96 mg/L), COD (628.34 mg/L), BOD5 (12.29 mg/L), PO43—P (0.29 mg/L), NH3N (0.65 mg/L), NO3—N (1.52 mg/L), NO2−-N, TN (2.26 mg/L), Mn (0.04 mg/L), Zn (0.03 mg/L), Fe (0.27 mg/L), Cu (0.09 mg/L), Ca (0.51 mg/L), Mg (1.12 mg/L), Na (6.59 mg/L), K (0.68 mg/L), E. coli (4491.67) and TC (14,279.17 CFU/100 mL). Most of the physicochemical parameters and coliform counts met national and international standards. However, EC, TS, TSS, BOD, and COD exceeded Ethiopian standards and international limits. Despite this, farmers continued to use the wastewater for irrigation, potentially leading to long-term adverse effects on both life and the environment. In conclusion, this study highlights the importance of implementing advanced treatments to ensure that brewery wastewater meets specific parameters for irrigation suitability.