Most of the landfill sites are suffering from the toxicity problems which exert pollution to their soil and underground water rendering it unusable for further applications. Printed circuit boards (PCBs) constitute one of the major sources of such toxicity in the landfill areas throughout the world. Hence, PCB recycling and separation of its metallic and nonmetallic components has been considered a major breakthrough in this direction. There are a lot of studies focusing on the metallic fraction of the PCBs due to its economic benefits whereas the nonmetallic fraction (NMP) has been left isolated.

This work investigates the feasibility of producing adsorbent from waste NMP and its possible application to remove the positively-charged toxic heavy metal ions from effluents.

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Most of the landfill sites are suffering from the toxicity problems which exert pollution to their soil and underground water rendering it unusable for further applications. Printed circuit boards (PCBs) constitute one of the major sources of such toxicity in the landfill areas throughout the world. Hence, PCB recycling and separation of its metallic and nonmetallic components has been considered a major breakthrough in this direction. There are a lot of studies focusing on the metallic fraction of the PCBs due to its economic benefits whereas the nonmetallic fraction (NMP) has been left isolated.

This work investigates the feasibility of producing adsorbent from waste NMP and its possible application to remove the positively-charged toxic heavy metal ions from effluents.

In the first phase of the study, the NMP is activated under various conditions, namely impregnation time, impregnation ratio, impregnation temperature, furnace temperature and activation time. The optimum condition in terms of surface areas of the samples has been determined and the optimum sample (A-NMP) has been fully characterized. The mechanism of the activation has been hypothesized by comparing the characteristics of the optimum sample with those of the untreated material. It is considered that it is possible to use this activated material for heavy metal adsorption purposes due to the development of a porous structure and surface functional moieties on the material.

The second phase involves the employment of the produced material for wastewater treatment. Therefore, the adsorption capacity of this material for copper, lead, zinc, nickel and cobalt has been evaluated in both the single- and multi-component systems. It has been shown that the untreated material has no adsorption capacity for any of the metals, whereas the adsorption capacity of the modified material is 3 mmol Cu, 3.4 mmol Pb, 2 mmol Zn, 3.4 mmol Ni and 3.5 mmol Co per gram of the adsorbent. These values are not only higher than the untreated material, but also much higher than the adsorption capacities of the three widely-used commercial adsorbents used in this study. It has also been shown that the adsorption capacity of this material does not decrease in multi-component systems and in some cases, even shows a synergistic effect. Furthermore, depending on the difference between the electronegativity of the metal ions present in the solution, this material can have either selective or simultaneous adsorption in multi-component systems.

The single-component modeling shows that this material exhibits a completely Langmuir behavior indicative of monolayer adsorption in a homogeneous surface. The extended modified Freundlich model was the best-fit equation for the multi-component system.

The kinetics of the adsorption have been performed and modeled. It has been demonstrated that the Pseudo-second order model fits the experimental data better than the other studied models. Moreover, the effect of pH, adsorbent dosage and initial concentration of the metal solution has been fully studied.