# Characterization and Use of Char Produced from Pyrolysis of Post-Consumer Mixed Plastic Waste
###### Abstract
On the other hand, the char obtained from pyrolysis was thermally activated at 900 \({}^{\circ}\)C for 3 h at atmospheric pressure to improve the contact area and pore volume of the char. Another application of interest is the one proposed by [PERSON] et al. [7], in which previously washed PET plastic waste is pyrolyzed in a temperature range from 300 to 700 \({}^{\circ}\)C. The char obtained from this process is used based on (as an) an additive to replace 10-50% of epoxy resin in the manufacture of epoxy composites. The char with the best properties for this application was the one obtained at 300 \({}^{\circ}\)C.  
On the other hand, lead (II) pollution is a global problem that has different life-threatening effects. It is ubiquitously present in the environment as a result of some anthropogenic activities, mainly, combustion of fossil fuels, mining and industrial activities [20]. For the remediation of lead (II)-contaminated wastewaters, some technologies have been used. Between them, adsorption onto low-cost and available adsorbents is a promising method [21]. Some studies have applied chars produced by pyrolysis as low-cost adsorbents of lead from aqueous solutions and have reported good adsorption properties that in general varied with pyrolysis temperature [22; 23; 24; 25; 26; 27; 28]. For example, [PERSON] et al. [22] investigated tire char as adsorbent to remove lead from aqueous solution and found a maximum lead adsorption capacity of 135 mg/g at pH of 5. [PERSON] et al. [26] pyrolyzed waste chicken bones from restaurants and also reported a high lead adsorption capacity (263 mg/g at pH 5). [PERSON] et al. [24] investigated biochars produced from pyrolysis of wood and bark as adsorbents in the removal of arsenic, cadmium and lead from water. These authors revealed that the ability of oak bark char to remove Pb (II) was extraordinary when it was compared to that of commercial activated carbon in terms of the amount of metal adsorbed per unit surface area (0.5157 mg/m\({}^{2}\) for Pb (II)). Recently, [PERSON] et al. [25] studied the lead (II) adsorption from synthetic wastewater by biochars produced by microwave-assisted pyrolysis. Particularly, lead (II) adsorption was especially high (165 mg/g) for canola straw biochar produced at 500 \({}^{\circ}\)C. [PERSON] et al. [29] also analyzed the ability of pecan shell biochar to adsorb lead from aqueous solutions. The authors reported that pecan shell biochar showed an adsorption capacity of 36.5 mg/g. Although much is known about lead (II) adsorption on biochars derived from agricultural and forestry adsorbents using conventional pyrolysis methods, studies on biochars produced from plastics waste are lacking. Only the works of [PERSON] et al. [10; 30] or [PERSON] et al. [18] have analyzed the effects of char obtained from pyrolysis of plastics for removing heavy metals from aqueous solutions. Particularly, [PERSON] et al. [10] studied chars from the pyrolysis of PVC, PET and PE, and [PERSON] et al. [30] and [PERSON] et al. [18] studied chars from the pyrolysis of mixtures composed by biomass, plastics and scrap tires. In this research, the pyrolysis of plastic waste from the reject fraction of municipal solid waste treatment plants (non-recyclable mixed plastic) was carried out. This post-consumer plastic waste consists of a mixture of polypropylene, polystyrene and polyethylene film. As a product of pyrolysis, a solid was obtained which was characterized and tested for its use as adsorbent of lead present in aqueous media.