Tree bark can clean polluted water — study

Don’t look now, but tree barks, which are considered wastes, can be used to clean water polluted with toxic metals, especially lead.

Chemist Jennifer P. Tamayo of the Los Baños-based DOST-Forest Products Research and Development Institute (FPRDI) found this after studying the potentials of the barks of eight tree species to trap ions (atomic particles) of lead and chromium present in the wastewater of a steel galvanizing plant. (Lead causes kidney and liver cancer while chromium causes biological mutations.)

The tree species were raintree (acacia), Acacia mangium, bagras, river red gum, gubas, moluccan sau, kaatoan bangkal, and yemane.

Tamayo conducted the thesis for her master of science in Chemistry thesis at UP Los Baños under the guidance of Dr. Maxima Flavier.

"Barks have tannin, lignin, organic acid, and cellulose that can absorb or trap heavy metals in solution," Tamayo noted. "these have the potential to substitute for costly synthethic adsorbents presently imported by the wastewater treatment industry at about $8 million a year."

Her experiments showed that waste barks can remove 96-100 percent lead and 84-90 percent chromium from waste water.

"This technology, once adopted, could help make industries better able to comply with present and future environmental laws," stressed FPRDI director Dr. Florence Soriano.

The Philippines produces a lot of waste barks from its 653,000 hectares of industrial tree plantations. – RAF