Water Quality Status of Petani River Basin Based on Water Quality Index and Physico-Chemical Properties

Hazzeman Haris* and Wan Maznah Wan Omar

School of Biological Sciences, Universiti Sains Malaysia, 11800 Pulau Pinang, Malaysia.

(*Corresponding author: Tel: 013-5019425, Email: ha33eman@hotmail.com)

ABSTRACT

Water samples were collected from 6 sampling stations along the Petani River Basin. Water Quality Index (WQI) was used to classify the river basin according to the pollution level where 100 represent the highest water quality. The subindex for each parameter used in the WQI equation was calculated. These parameters are dissolved oxygen, biological oxygen demand, chemical oxygen demand, pH and ammonia. Other parameters such as alkalinity, nitrite, nitrate, orthophosphate, salinity and TDS were also determined. During the 12 months sampling period, the highest WQI was recorded at the Petani River-Jetty (74.21) in February 2006 and the lowest was recorded at Bakar Arang River (38.54) in August 2006. Generally it can be said that the sampling stations that were located near the town centre and tributaries that flows through industrial area showed lower WQI value compared to other sampling stations that were located further downstream or tributaries that flow through residential areas. Gelugor River recorded a higher concentration of nitrite and nitrate compared to other sampling stations. Petani River-Jetty on the other hand recorded a higher level of total suspended solids (TSS). One-way ANOVA (p less than 0.05) showed no significant differences in the amount of orthophosphate and ammonia between all the sites but there were significant differences between sampling intervals.

Keywords: Water Quality Index, physico-chemical properties, nutrients

THE 2ND REGIONAL CONFERENCE ON ECOLOGICAL AND ENVIRONMENTAL MODELLING 2007 (ECOMOD 2007), PENANG, MALAYSIA