Uptake of copper and chromium by Avicennia marina and Avicennia alba at Wonorejo Estuary, East-coastal area of Surabaya, Indonesia

Abstract

Wonorejo River is one of the rivers that discharge into the East Coast area in Surabaya, Indonesia. This river also contains wastewater from industry and households and can be polluted at the estuary area in Surabaya. Avicennia marina and Avicennia alba are mangrove species that have a high population at the Wonorejo Coastal area. This area was planted with mangroves 10 years ago. The aims of this research were to determine the concentration of Cu and Cr in sediment and the roots of A. marina and A. alba at the Wonorejo Coastal area, to determine the value of Bioconcentration Factor (BFC) of Cu and Cr by A. marina and A. alba and to determine the distribution of Cu and Cr concentration in sediment. Sampling activities were conducted using a Transect quadrat sampling method with a 10 x 10 m dimension. Sediment and mangrove root samples were extracted before being analysed using an atomic absorption spectrophotometer (AAS). Based on Interim sediment quality guidelines (ISQGs), the average concentrations of Cu and Cr at some sampling points were above the standard, i.e Cu reached 94.0 ± 79.2 mg/kg and Cr was 70.8 ± 20.2 mg/kg. A. marina could uptake metals and the accumulations of Cu and Cr were 110 ± 10.4 mg/kg and 83.8 ± 10.6 mg/kg, respectively. However, the highest accumulation by A. alba reached 90.8 ± 24.7 mg/kg for Cu and 55.3 ± 1.1 mg/kg for Cr. Based on the BCF value, A. marina was a hyperaccumulator species for the heavy metals Cu and Cr. However, A. alba showed potential as a hyperaccumulator for Cu and as an accumulator for Cr. In conclusion, both mangroves A. marina and A. alba can be considered for use in Cu and Cr phytoremediation in coastal areas.