Effect of Different Filtration Methods on Drinking Water Quality Parameters in Parts of Onitsha, Anambra State, Nigeria

Abstract

This work studied the effect of three filtration processes on some water quality parameters of selected boreholes and sachets of water sold in Onitsha North LGA. A total of ten water samples were collected each month for a period of six months. Five samples were collected from five different boreholes while another five samples were sachet water from five water companies. The samples collected were treated with different water filtration processes, namely Carbon filtration (CF), Ceramic Candle filtration (CCF) and Step Filtration System (SFS). Sample analysis was conducted using Atomic Absorption Spectrophotometer (AAS) for calcium and magnesium ion and standard test methods for pH and TDS. The Water Quality Index (WQI) was also calculated. The results obtained were compared with World Health Organization (WHO) standards. It is evident from this study that some of the selected water samples (borehole and sachet water) in Onitsha North, Anambra State met the recommended standards for physicochemical qualities. The TDS of the samples during the period of study were all below the threshold limit (1000 mg/L) allowed. For the months of December, 2016, and January, 2017, 40% of sampled water was below the recommended pH value range of 6.5 to 8.5. In the months of February, March, and April, 2017, 70 % of sampled water was below the WHO pH range, while in May, 2017, only 30 % of sampled water was below the WHO range. The acidic samples were neutralized on treatment with the different filtration processes. The WQI analysis of the sampled water showed that the water were suitable for human consumption as the values fell within 0-25 (Excellent) and 26-50 (good). The overall trend of filtration efficiency was SFS > CCF > CF. It is highly recommended that regular monitoring be conducted and municipal filtration processes be used to augment the water purification.