Removal of copper ions from aqueous solution using NaOH-treated rice husk

Abstract

The present study investigates the removal of copper ions (Cu (II)) from aqueous solution using chemically treated rice husk (TRH). The chemical treatment was carried out using NaOH solution and the effect of contact time (tc), adsorbent dosage (Dad), initial Cu (II) concentration ([Cu]i), and temperature (T) on the percentage removals of Cu (II) (%RCu) were investigated. Different analytical techniques (FTIR, SEM, and EDX) were used to confirm the adsorption (ads) of Cu (II) onto the TRH. The ads kinetics was tested against pseudo-first-order (PFO) and pseudo-second-order (PSO) models as well as Langmuir and Freundlich isotherms. Treating RH with NaOH altered the surface and functional groups, and on the surface of RH, the ionic ligands with high electro-attraction to Cu increased and thus improved the removal efficiency. The %RCu decreased by increasing the [Cu]i and increased by increasing the ct, Dad, and T. Up to 97% Cu removal was achieved in ct of 30 min using Dad of 0.3 g [Cu]i of 25 mg L−1 and T = 280 K. The ads of Cu on TRH is endothermic, spontaneous, follows Langmuir isotherms, and exhibited a PSO kinetics. Moreover, the TRH was successfully regenerated and used for further adsorption cycles using 1 M HNO3.

Synthesis and Characterization of Rice Husk Biochar and its Application in the Adsorption Studies of Lead and Copper

“…for Freundlich was 0.9187 implying that monolayer adsorption of Cu(II) ions on the homogeneous surface of the rice husk biochar was the prevalent similar result of copper was reported by[32]. As depicted in Tables1 and 2the values of n in Freundlich isotherm signifies the heterogeneous surface in Pb(II) and Cu(II) metal ions because it lies between 1 and 10 indicating a favourable reaction and also a strong bond between adsorbent and metal ions.…”

Kinetic and equilibrium studies on bioadsorption of copper and lead by water hyacinth (Eichhornia crassipes) plant powder

“…Large numbers of techniques for the treatments of waste water had already been reported in the literature which are solvent extraction, oxidation, electroflotation, membrane filtration, reverse osmosis and coagulation. [11,12] The methods mentioned above have not gained much popularity till date because they have some disadvantages like complicacy in treatment, need of high energy and of course high cost. Activated carbon can also be used as an efficient technology to reduce the concentration of heavy metals like Pb(II) and Cu(II) from drinking and industrial waste waters.…”

Assessment and treatment of floodwater in the Vietnamese Mekong Delta using a simple filter system based on silver nanoparticles coated onto activated carbon derived from rice husk

“…In fact, AC made from rice husk exhibits high effectiveness in the treatment of not only organic compounds, [11][12][13] but also heavy metals. 14,15 As mentioned above, oodwater is a suitable residence for microorganisms, particularly disease bacteria. In addition to the pollutants and organic substances, the ingredient of harmful microorganisms in oodwater is necessary for treatment.…”