Reed plants such as Umbrella plant, Bandera Española and Wedelia are promising plants to phytoremediate heavy metals in the Calao-Delinquente-Diadi River in Santiago City, Isabela in Region 2. This was the initial result of the study conducted by the Watershed and Water Resources Research Development and Extension Center (WWRRDEC) from November 2019 to June 2019 in the said river system.
Phytoremediation involves the use of green plants/vegetation to contain, sequester or degrade inorganic and organic contaminants in soil, sediments, surface and groundwater and air. Each experimental plant has the capability to remediate polluted water system though at different levels, and depending on the type of pollutant.
The three (3) experimental plants were selected based on their availability in the locality and were raised at the nursery of the WWRRDEC Northern Luzon Ecosystems Research Station (NLERS) in Diadi, Nueva Vizcaya.
These indigenous plants were propagated in recycled plastic bottles attached to an improvised floating bed made of bamboo poles. These were floated on the said river for 8 months (November 2018-June 2019) to sequester heavy metals such as nickel (Ni) and lead (Pb) before they were harvested.
Result of analysis showed that the reed plants were able to absorb Pb and Ni though at different extent. Bandera Española, recorded the highest lead absorption with an average of 4.88 ppm followed by the Umbrella plant with 2.53 ppm and Wedelia with the least of 2.11 ppm. On the other hand, Wedelia had the highest average absorption of Ni by 3.13 ppm while Bandera Española and Umbrella plant absorbed 1.81 ppm and 1.67 ppm, respectively.
The result, however, is not conclusive since data gathering was only done within a short period due to natural calamities such as typhoons and heavy rainfalls that inundated the river causing damages to the experimental set-up.
Thus, more extensive research on these plants and other reed plants should be undertaken to determine their absorptive capacity in sequestering pollutants in different river systems. Using these plants for phytoremediation projects will help bring back the gorgeous state of our vital rivers. Linda B. Sauyen, WWRRDEC