Potential of silica from water treatment sludge modified with chitosan for Pb(II) and color adsorption in sasirangan waste solution

Abstract

Water treatment sludge (WTS) still contains a lot of silica oxide (SiO2) as much as 43.12-66.90% by weight and can act as an adsorbent to be applied to the treatment of Sasirangan wastewater. Silica extraction from WTS was carried out by microwave-assisted leaching, which - compared to conventional extraction - had several advantages including high extraction yields, fast, uniform, and more selective processing time. In addition, Sasirangan liquid waste is a by-product of the dyeing process of Sasirangan cloth, which still contains heavy metals in amounts exceeding the quality standard. This study aims to extract silica from WTS by microwave-assisted leaching process to synthesize silica modified by chitosan (Si-Kit) as an adsorbent to reduce Pb(II) from Sasirangan wastewater, and to obtain a kinetic model of the adsorption process. The silica from microwave-assisted leaching process (Si-MaL) and Si-Kit adsorbents were characterized using FTIR and SEM. The results showed that the dominant functional groups of Si-Kit included Si-O-Si, Si-O-C stretching vibrations, and stretching vibration of C=N showing that the condensation between aldehyde groups and amino groups occurred to form base after the addition of glutaraldehyde. The SEM images showed that Si-MaL and Si-Kit adsorbent obviously increased in particle size with the presence of visible particles of homogeneous granules and large pores. The removal efficiency percentage of Pb(II) and color occurred at 6% w/v adsorbent weight and 70 min was 87.20% and 61.87% respectively. Meanwhile, the adsorption kinetics of Pb(II) and color followed the zero order kinetics model at weight variation of 6%-w/v based on the value of R2 close to one and the adsorption capacity of Pb(II) ion and color were 12.01 mg g-1 and 467 mg g-1, respectively.

One-stage microwave-assisted activated carbon preparation from Langsat peel raw material for adsorption of iron, manganese and copper from acid mining waste

“…This chemisorption process aligned with previous studies on agricultural waste [ [70][71][72]. The proximity of the coefficient of regression (R²) to unity (1) [73][74][75] was employed to assess how well the determined model suited the data, so as a result, the predicted R 2 values from the PSO model matched well with the experimental values. This is also in line with the research findings that the data follows Langmuir isotherm adsorption (monolayer).…”

Palm oil mill effluent (POME) precipitation using ammonium-intercalated clay coagulant

“…Several methods have recently been improved for oil-based waste treatment, such as Fenton oxidation, membrane separation, adsorption, flocculation, and coagulation [5,6].…”