<Note>Metal Distribution in the Laguna Lake Water System and Adsorption of Some Metals by Carbonized Wood Powder

Abstract

The metal distribution in the Laguna lake water system was assessed using water samples taken from the surface, middle and bottom portions of the lake at five designated sampling points. Trial purification of the wastewater was conducted using raw and carbonized wood powder from wood wastes of Acacia mangium. Beneficial and dangerously toxic metals were present in all the water samples. Sodium (Na) was the most dominant alkali metal followed by potassium (K), magnesium (Mg) and calcium (Ca). Toxic metals such as arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), lead (Pb), iron (Fe), mercury (Hg), zinc (Zn), etc., were found but each concentration was below the water quality criteria set by the National Pollution Control Commission of the Philippines. Adsorption tests showed that wood waste from Acacia mangium could be a potential purification material in treating Laguna lake water samples, and especially raw and carbonized wood powder of this species could be used as material in adsorbing heavy metals like Zn and Cu.