Removal of Pb²⁺ from industrial wastewater using activated carbon from Persea americana seed

Remoção de Pb²⁺ de efluentes industriais utilizando carvão ativado de semente de Persea americana

Abstract

Activated carbon is a material that has various environmental applications, such as the adsorption of metallic lead ions (Pb²⁺). It can be obtained from different plant species. In this research, the seed of Persea americana (Avocado- HASS variety) was obtained from local markets in the city of Cartagena to be used in the removal of Pb²⁺ from wastewater from the fishing industry. To obtain activated carbon, the seed was carbonized in a Terrigeno-brand clay oven, Model DB 1200. Orthophosphoric acid at 21% w/v was used as an activating agent. The residual water was characterized following the APHA specifications. The turbidity was determined by nephelometry in a Turbiquant 300 IR turbidimeter. The Pb²⁺ concentration was determined by atomic absorption spectroscopy in a Thermo Scientific iCE 3300 equipment. The chemical surface of the material was performed by Fourier transform infrared spectroscopy (FTIR). The carbons were morphologically characterized using a scanning electron microscope SEM (Jeol 5910LV), visualized at 15kV. A yield of 20.38% by mass of coal is achieved. The pores are of irregular size, ranging from 16.2 to 55.98 μm. 65% of Pb²⁺, turbidity (57.6%), color (57%), total solids (50.2%), as well as BOD (53.12%) and COD (36%) are removed, finding statistically significant differences in values at the 95% level of significance. The seed of Persea americana (HASS avocado) can serve as plant material to obtain an adsorbent material (activated carbon) and be used in the removal of Pb²⁺ from wastewater.

Keywords:
activated carbon; adsorption; avocado seeds (HASS variety); Pb²⁺; removal