Aproveitamento de resíduos da indústria de processamento de carnes na remoção de nitrogênio de águas por adsorção

Abstract

Wastewater treatment is becoming more susceptible to environmental inspections, as industrial wastewater is a major cause of surface water pollution when discharged into the water body without an adequate treatment process. High nitrogen loading in water bodies can cause serious environmental impacts, such as eutrophication and environmental toxicity. One of the processes that can enable the removal of nitrogen from effluents is adsorption, which is a process in which the use of alternative adsorbents has been applied for waste utilization and reducing process costs. Based on this assumption, the present work aims to demonstrate a process of synthesizing an adsorbent and application for nitrogen removal from water. The synthesized material can be used by the generating company itself, as an example is the sludge from the flocculation stage of the Effluent Treatment Station (ETE), the ashes from the boiler and the analytical reagent Al2(SO4)3, which served for use in removing inorganic nitrogen. For this we used the hydrothermal zeolitization method, which is already being widely used, and is present in the chemical structuring processes, besides this methodology we opted for a second little known method called dry-gel. Materials synthesized with synthetic effluent (NH4) 2SO4 were tested at concentrations of 158.06, 299.18 and 557.34 mg/L, respectively, as well as with an actual effluent. For synthetic effluent, the adsorbed amounts ranged from 4.23 to 12.9 mg/g, between syntheses II, III and IV. For the actual effluent, the amount adsorbed was 1.46 mg/g, 2.23 mg/g and 2.01 mg/g, for syntheses II, III and IV, respectively. The synthesis II product (calcined sludge + ash + NaOH solution), although not presenting the highest value of adsorbed quantity, presented potential for application in nitrogen removal from effluents through adsorption (1.46 mg/g) and consequent utilization.