Paper mill sludge, a waste derived from papermaking, is a good material in asphalt road pavement work.
“The fibers from paper mill sludge can withstand harsh processing, including high temperature for mixing with asphalt, as shown by the presence of fibers that were recovered after extraction,” reported the Los Baños-based Department of Science and Technology-Forest Products Research and Development Institute (DOST-FPRDI).
Based on a research it had conducted, FPRDI averred that the use of paper mill sludge, instead of imported paper additive in asphalt mix for road pavement, also promises big savings.
About P240,000 can be saved in paving a one-kilometer, three-meter wide, and five-centimeter thick road using paper mill sludge instead of imported fiber.
In the study, FPRDI assessed the possibility of using paper mill sludge and wastepaper as fiber additive in stone mastic (protective coating or cement) asphalt mix for road pavement.
The sludge was dried, ground, and then sieved. The resultant material was mixed with aggregates and asphalt and then applied with heat, mixing, and mechanical compaction.
The process turned out encouraging results.
However, FPRDI conceded, “there is still a need for pilot-scale study to establish the economic viability of this technology, as well as the long-term performance of the asphalt mix in road pavement.”
The study’s significance becomes more appreciated when one considers that paper mills in the country produce about 84,000 metric tons of paper mill sludge per year. These wastes, if not disposed of or used properly, can become an environment problem, pointed out the Philippine Association of Pulp and Paper Mills (PULPAPEL).
To date, paper mill sludge is commonly used as landfilling, land spreading, fertilizer, and low-grade paper such as boxboard, reported Dr. Leila America of the Los Baños-based DOST-Philippine Council for Agriculture, Forestry, and Natural Resources Research and Development (PCARRD). — Rudy A. Fernandez