Utilization of lignite coal as heavy metal adsorbent in chemistry laboratory wastewater

Abstract

Wastewater from Chemistry Laboratory contains heavy metals which need treatment before being discharged into the environment. This study investigates the treatment of chemistry laboratory wastewater using activated carbon. The activated carbon was made from lignite coal with ZnCl2 activation and carbonization was carried out at a temperature of 500°C for 2 hours. The highest iodine number is 1529.20 mg/g on activated carbon with a grain size of 80 mesh of coal and a composition of 40% ZnCl2-60% coal. Adsorption of Fe, Cr and Pb metals using activated carbon was carried out at 2 variations of initial concentrations. At an initial concentration of 75.8 ppm Fe, metal adsorption is 84%, while at an initial concentration of 37.9 ppm it is 87%. The adsorption of Cr metal is 44% at an initial concentration of 1.37 ppm, and it is 79% at an initial concentration of 0.69 ppm. The adsorption of Pb metal is 91% at an initial concentration of 11.2 ppm, and it is 91% at an initial concentration of 5.6 ppm. The results showed that activated carbon from lignite coal could adsorb Fe, Cr and Pb metals, and the initial concentration influenced the effectiveness of metal adsorption.

Responses of diatom composition and teratological forms to environmental pollution in a post-mining lake (SW Poland)

“…In relatively shallow lakes, as a result of wind activity and resuspension of sediments, heavy metals are released into the water, and their circulation is quite intensive (Mrozińska and Bąkowska 2020 ). On the other hand, brown coal is very effective as an adsorbent material (Suliestyah et al 2021 ). On the surface of lignite, the adsorption process causes the binding of molecules, ions, or atoms of pollutants and heavy metal compounds.…”

Dynamic experiments of acid mine drainage with Rhodopseudomonas spheroides activated lignite immobilized sulfate-reducing bacteria particles treatment

“…Lignite is rich in aromatic benzene ring and functional group-like petroleum structures, such as aliphatic hydrocarbons, aromatic hydrocarbons, carbon and oxygen branched chain 14 . These functional groups can undergo chemical reactions such as ion exchange, coordination and complexation with metal ions to achieve the adsorption effect 15 . Bao et al 16 showed that the removal efficiency of Cu 2+ by lignite reached 67.84 mg/g.…”