Removal of heavy metal ions (Pb²⁺ and Ni²⁺) from aqueous solution using nonwovens produced from lignocellulosic milkweed fibers

Abstract

Batch-adsorption technique was employed to evaluate the adsorption capacity of the nonwovens produced from lignocellulosic milkweed fibers for the removal of heavy metal ions, i.e. Pb2+ and Ni2+, from aqueous solutions. The impact of controllable factors such as solution pH, initial concentration, contact time and operating temperature on the adsorption quantity of Pb2+ and Ni2+ was investigated using Atomic Absorption Spectrophotometer. The kinetic and isotherm of the adsorption process were also modeled. The milkweed fibers demonstrated superior performance for the removal of Pb2+ ions from wastewater over Ni2+ ions. The results demonstrated that the equilibrium concentration of heavy metal ions in solution varies with solution pH and the least equilibrium concentration is observed at pH = 6, regardless of ion type. The results also revealed that the removal percentage of Ni2+ ions reached the value of 65.58% at contact time of 60 min while Pb2+ ions removal percentage was as high as 96.16% at contact time of 90 min. It was concluded that an increase in operating temperature from 26 to 45°C causes to slight decrease of the removal percentage for both Pb2+ and Ni2+ ions by ∼5.7% and ∼9.5%, respectively. The adsorption behavior of milkweed fibers toward Pb2+ and Ni2+ ions followed Freundlich and Langmuir isotherm models, respectively. Moreover, pseudo-second order model was the best to describe the adsorption kinetics of both metal ions.

Study of adsorption isotherms on removal of Cu (II) solution using activated carbon of sugar palm fruit shell (Arenga pinnata)

“…Then, it decreased until 100 min and increased along with the longer contact time prior to the equilibrium was attained in 90 min. At the time, The result is similar to what was reported [16] by using adsorbent nonwovens produced from lignocellulosic milkweed fibers. More active sites have not occupy the surface which provide greater opportunities for the adsorption process of Cu (II) ions with active sides of the SPFS activated carbon.…”