ASSESSMENT OF CONTAMINATION LEVEL AND SOURCE APPORTIONMENT OF HEAVY METALS IN SERAYU RIVER WATER, INDONESIA

Abstract

Diverse community activities along the river can alter water quality, particularly heavy metal pollution, which can negatively affect public health. This study examines the contamination and distribution of heavy metal sources in the Serayu River, one of the longest and largest rivers in Central Java Province in Indonesia. Along the Serayu River, water samples were obtained from 18 distinct sampling points. Heavy metals content in water samples was measured for lead, cadmium, chromium, nickel, arsenic, cobalt, iron and manganese. Pb, Cr and Ni Concentrations have surpassed government rule No. 22 of 2021 regarding quality criteria in several locations. The contamination factor (CF) determines the level of heavy metal pollution in the Serayu River. The average value of CF, from highest to lowest, is as follows: Pb (2.03); Ni (0.24); Cr (0.24); Fe (0.21); Mn (0.10); Co (0.04); Cd (0.04); As (0.02). The modified degree of contamination (MCD) suggests that the bulk of river water falls into moderate contamination. Agricultural practices in the upper reaches of the Serayu River are regarded as the primary source of surpassing the quality level. Multivariate statistical analyses, namely principal component analysis (PCA), pearson correlation matrix and cluster analysis (CA), revealed that most heavy metals originated from various human activities. Pb, Cr and Ni were primarily derived from agricultural activities, whereas Cd, Co and Mn were primarily derived from industrial, agricultural, settlements and tourism. As and Fe are primarily derived from mining. The alternative recommendation for contamination recovery is the application of biochar which is economically affordable material to be applied in the river.