Abstract:
Water is crucial for all aspects of life, for defining feature of our planet. Wastewater from households and industries was one of poor environmental performance in managing. This study aimed to determine whether inadequate treatment of wastewater and the faecal pollution load of effluents and receiving water bodies in Akaki Rever Bole Bulbula sites in Addis Ababa Sewarege and water Authority (AASWA) could be a potential threat to the health of the surrounding communities. The result showed that sampling sites include, influent, effluent, and receiving water bodies (Akaki River) in the physicochemical parameters (Temperature, pH, DO, EC, TDS of treated water (effluent, S2) compared with raw wastewater directly released from households (influent, S1) concerning the mean value of DO values in S1, S2, S3, and S4 had an average value of 6.44,16.3,14.53, and 5.54 in mg/l units respectively. The average EC value in this study in the four sampling points namely S1, S2, S3, and S4 was 856, 947.6, 530.38, and 612.88 in µs/cm units respectively. Lastly, the TDS also had an average value across the four sampling site S1,551.7, S2 597.3, S3 259.5 and S4 279.3 in mg/l units. The pH of wastewater in this study across the four sampling sites and the four consecutive sampling months shows slightly basic and similar to the standard of WHO 5,6,7,8 but there is a big variation in DO, EC, and TDS.. This result showed that temperature and pH value had no much difference, but DO in S4 accounts minimum where as in S2 was maximum. This may be showed that a lot of contaminated water and eroded minerals dissolved in the river. EC and TDS are much greater in S2 than the receiving river; which are optimized by chemicals in this membrane bioreactor (MBR) technology. Bacteriological parameters of wastewater released from households (S1) with regards to the mean of E. choli 3.7525*105 cfu/100ml and Enterococci 2.5475*105 cfu/100ml. Treated water effluent (S2) 7.775*104 for E. choli and 5.075*104 cfu/100ml for Enterococci. The receiving water bodies( S3) had an average value of E.coli 9.545*105 cfu/100ml and 4.2875*105 cfu/100ml for Enterococci before the effluent was added. Finally, the S4, after the effluent was added into the receiving water bodies, had an average value of 1.794*106 cfu/100ml for E.coli and 7.05322*105 cfu/100ml for Enterococci. This average result shows that higher bacterial concentration in sampling site 4. As usual, the treated site (S2) in this river had the lowest bacterial loads as compared to other sites and WHO standards for full and intermediate contact recreational use (<1E. coli/100 ml and <40 faecal enterococci/100 ml, respectively). These findings demonstrated that potential health risks might be associated with the use of the target river waters for domestic, recreational and irrigation purposes. This study calls for a prompt intervention to improve wastewater management by MBR technology to achieve SDG-6.
