Tree barks can clean industrial waste water

Don’t throw away those waste barks from industrial tree plantations.

These can be used to clean polluted water of toxic metals, especially lead, it was found in a study done by chemist Jennifer P. Tamayo of the Los Baños-based Department of Science and Technology-Forest Products Research and Development Institute (DOST-FPRDI).

Tamayo studied the potential of barks of eight tree species to trap ions of lead and chromium present in the wastewater of a steel galvanizing plant. Chromium causes biological mutations while lead causes kidney and liver cancer.

"Barks have tannins, lignins, organic acids and cellulose that can absorb or trap heavy metals in solution. Thus, they have the potential to substitute for costly synthetic adsorbents presently being improted by the wastewater treatment industry at about US$8 million a year," the FPRDI researcher said.

She emphasized that the Philippines produces a lot of waste barks from its 653,000 hectares of industrial tree plantations established by both government and private groups. Making up 10-20 percent of the trunk’s total volume, barks remain an untapped resource.

Dr. Florence P. Soriano, FPRDI director, also said that the technology, once adopted, could help make industries better to comply with present and future environmental laws."

Tamayo’s research showed that waste barks can remove 96-100 percent lead and 84-90 percent chromium from wastewater as reported by FPRDI’s Rik Araral.

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

Among these, gubas and river red gum gave the best results since their barks removed the most ions and did not impart color in solution. These species can be used for wastewater treatment in process industries.

Tamayo conducted her research as a Master of Science in Chemistry study at UP Los Baños under the guidance of Dr. Maxima E. Flavier. – RAF