MANAGEMENT STRATEGY OF AN INVASIVE WOODY PLANT SPECIES THROUGH CONVERSION INTO ADSORBENTS FOR REMEDIATION OF POLLUTED WATER

G. NUNELL; P. BONELLI; A. L. CUKIERMAN

Management strategy of an invasive woody plant species through conversion into adsorbents for remediation of polluted water

Nova Science Publishers, Inc

Lugar: Hauppauge; Año: 2016; p. 55 - 80

A strategy for managing invasive woody plant species, which constitute a majorthreat to biodiversity worldwide, is to identify value-added uses. In thisdirection, wood from invasive species may result an attractive option asabundant, renewable feedstock for the sustainable manufacture of adsorbents forenvironmental applications, contributing to control their spread. Amongworldwide invasive species, Parkinsonia aculeata, belonging to the Fabaceae family, is in the league of the most noxious woody plants.It can form dense, and often impenetrable thorny thickets along watercoursesimpeding access to drinking water supplies, excluding native vegetation, andcausing soil erosion. Although different routes have been proposed for itsmanagement, control is still difficult. Within this scenario, the presentchapter explores the feasibility of using Parkinsoneaaculeata wood as a feedstock for the sustainable development of adsorbentstargeted at pollutants removal from wastewater. For this purpose, the chemicalactivation process employing different chemical reagents is comparatively explored.Solutions of phosphoric acid, ammonium chloride, and potassium carbonate, involvingdifferent preparation conditions, are used. Characterization of chemical andtextural-morphological features of the resulting adsorbents is conducted by setof complementary techniques. Their performance in the removal of oxo-anions andorganic compounds from model dilute solutions, using nitrate ion and phenol as representativespecies of these kinds of water contaminants, is also investigated atequilibrium pre-established conditions. The activating agent strongly affectsyield, the elemental composition, surface chemistry, porous structuresdevelopment, and adsorptive performance of the adsorbents. Activation withphosphoric acid and potassium carbonate solutions leads to adsorbents withtypical features characterizing activated carbons, as evidenced in pronounceddevelopments of their porous structures with BET surfaces areas of 968 m2g-1 and 777 m2 g-1, respectively. Conversely,the sample obtained with the ammonium salt presents a slight porositydevelopment but a noticeably high N content. It shows the best behavior innitrate uptake, leading to the highest removal level among the developedsamples. Instead, only the adsorbents with well-developed porous structuresenable to attain high levels of phenol adsorption, pointing to a major role ofthe textural characteristics. Present results demonstrate that adsorbents adequatefor the removal of different kinds of pollutant species from wastewater may bedeveloped by chemical activation of invasive P.aculeata wood. Their characteristics and, consequently,adsorptive behavior may be conveniently tuned according to the nature of thecontaminant by a proper selection of the chemical reagent employed.