Efficient Removal of Zinc and Copper from Wastewater Using Activated Carbon Derived from Date Pits in a Continuous Fixed-Bed Column

Adsorbents based on agricultural biomass have been subjected to several investigations in recent years owing to their low cost and promising adsorption capabilities.This paper aimed to demonstrate the efficiency of date pits activated with phosphoric acid as common activating agent that increases the porosity and surface area of date pits.This results in a greater number of binding sites for the heavy metals to attach to improving the bio-adsorbent's effectiveness.To get rid of heavy metals such as zinc and copper ions from industrial wastewater using a fixed bed with a continuous flow configuration, the derived adsorbent was tested under a variety of operating conditions, including a flow rate of 4-12mL/min, an initial metal ion concentration of 30-60mg/L, and temperatures ranging from 20 to 50℃, which were chosen based on industrial conditions and available data.The results revealed that the removal efficiency of heavy metals increased with an increase in the initial metal ion concentration, but conversely, it decreased with an increase in flow rate and temperature.Also, the results indicated that with the optimum conditions of 15cm static bed height, 60mg/L initial metal concentration, 8mL/min flow rate, and 25℃ temperature, determining the ideal conditions results in the efficient removal of pollutants in less time and the treatment of larger quantities.Mathematical modeling of the fixed bed column was achieved using the kinetic models of Adams Thomas, Yoon-Nelson, Bohar, and Modified Dose-Response, in this regard, the Thomas model is the closest to the experimental values, it is supposed that the adsorption mechanism was a Langmuir type adsorption followed by a pseudo-second-order chemical sorption.The Yoon-Nelson approach was employed on experimental data to predict breakthrough curves through nonlinear regression.This made it easier to determine the crucial characteristic column parameters for process design.According to thermodynamic studies, heavy metals spontaneously and exothermally adsorb activated carbon in date pits.Firstly, spontaneous adsorption indicates efficient processes that occur favorably without external energy input, offering cost-effective solutions for various applications.Secondly, the exothermic nature of adsorption suggests that lower temperatures may be sufficient, reducing energy consumption and preserving the stability of sensitive materials.Additionally, the process's exothermicity facilitates desorption at higher temperatures, enhancing the efficiency of regeneration processes.This study has shown that BDP can successfully remove heavy metals from aqueous solutions.Understanding these characteristics is crucial for optimizing applications, reducing costs, and improving overall efficiency in industrial and environmental contexts.