DETERMINATION OF THE WATER QUALITY INDEX (WQI) OF A FRESH WATER STREAM (Mini-Whuo) ELIOZU, RIVERS STATE, NIGERIA.

Abstract

In order to assess the potability and agricultural application of Mini-Whuo stream in Eliozu Port Harcourt, Rivers State, Nigeria; the physicochemical properties, heavy metal levels (Fe, Cr, Cd, Pb & Ni) and microbiological load of water were evaluated. Five stations were established and sampling made for a period of six months (May-October 2019). Various water samples were collected for the analysis of physicochemical properties, heavy metal and microbiological levels, using titrimetric, spectrophotometric and microbiological methods respectively. Results obtained from the analyses showed that, temperature ranged between (28.7±0.7-30.9±1.9ºC), pH (6.4±0.0-6.7±0.3), electrical conductivity (82±20-172.0±14 µS/cm), total dissolved solids (41±1-86.5±71.1mg/l), turbidity (8.1±1.6-18.1±2.8 NTU), chloride (5.60±1.63-7.76±0.96 mg/l). Levels of heavy metals analyzed for water were below detection limit of 0.01mg/l, except for Fe which ranged between (3±1-4.6±0.8 mg/l). Microbiological study of water showed that the water had (2.6±0.5-6.4±0.6 x103 cfu/MLN) count of total heterotrophic bacteria, (44.3±9- 323.8±44 MPN/100ml-1) count of total coliform bacteria count and (4.3±2.7-59.5±16.9 MPN/100ml-1) faecal coliform bacteria count. From the result of analyses it was observed that iron, dissolved oxygen, electrical conductivity, total dissolved solids, and the microbiological load of the water were high when compared with WHO standards, and this may be attributed to the disposal of wastes such as, human and animal wastes into the water body. Water quality index (WQI) method according to the weighted arithmetic WQI, where (WQI < 50 = excellent water quality), (50 > WQI < 100 = good water quality), (100 > WQI < 200 = poor water quality), (200 > WQI < 300 = very poor water quality), and (WQI > 300 = unfit for drinking). Based on the WQI calculated for the Mini-Whuo stream 1156, the stream is not suitable for domestic use.