A STUDY ON THE IMPACT OF URBAN AND INDUSTRIAL-DEVELOPMENT IN THE LINGGI RIVER BASIN, MALAYSIA .2. CHEMICAL ENVIRONMENT

An investigation of the chemical environment of the Linggi River Basin was carried out at 15 main and 27 supplementary stations between January 1983 and January 1984. Spatial and temporal changes in pH, specific conductivity, alkalinity, chloride, ammonia-nitrogen, nitrite-nitrogen, nitrate-nitrogen, orthophosphate, dissolved oxygen, BOD, and diurnal variations were studied in relation to influence of various kinds of pollutants. The chemical composition of natural water analysed at a few undisturbed forest stream stations in the basin can be considered very good. A drastic change in river water quality was noticed in downstream polluted stations. The pH in the basin varied from 4.05 to 10.5 units, conductivity from 23.0-1,500 umhos/cm, alkalinity from 6.0-1,388 mg/l, chloride from 0.9-160.9 mg/l, orthophosphate from 0.5-5.21 mg/l, ammonia-N from 0.001-53.75 mg/l, nitrite-N from 0.0-8.2 mg/l, nitrate-N from 0.03-6.77 mg/l and BOD3 from 0.32-384.0 mg/l and COD from 0.02 to 79.2 unit. Among all the rivers, very high values were recorded at Kundor, Simin and Linggi (sensu stricto).