Efficacy of mangrove leaf powder for bioremediation of chromium (VI) from aqueous solutions: kinetic and thermodynamic evaluation

Abstract

Biosorption of heavy metals by bio-materials has been posited as a potential alternative to the existing physicochemical technologies for detoxification and recovery of toxic and valuable metals from wastewaters. In this context, the role of mangrove leaf powder (MLP) as biosorbent for chromium removal was investigated. In the present study, the effect of process parameters such as particle size, solution pH, initial concentration of Cr(VI) ion and adsorbent dose on chromium removal by MLP was investigated. The maximum sorption was observed at particle size 0.5 mm and pH 2.0. The adsorption data follow the pseudo second-order kinetics model. The isotherms denote that Langmuir model is the best fitted than Freundlich model. The maximum adsorption capacity (Q 0 ) of 60.24 mg/g of Cr(VI) at 30 min on MLP was determined using the Langmuir model. The adsorption isotherm model indicates that the chromium is adsorbing as monolayer on the surface of MLP with heterogeneous energetic distribution of active sites. Various thermodynamic parameters, such as Gibb's free energy (DG°), enthalpy (DH°) and entropy (DS°) have been calculated. The thermodynamic data revealed that the adsorption of chromium ions onto MLP is endothermic in nature and a spontaneous process. The results of the present study suggest that MLP is an effective bioremediation measure for removal of high concentration of Cr(VI) in waste waters.

Performance Evaluation of Cascade Separation for a Humic Substance and Nutrient Recovery from Piggery Wastewater toward a Circular Bioeconomy

“…As the R/W ratio increased from 1:5 to 5:5, the SAC for PW1 decreased from 1.251 to 0.482 mg/g, while reducing from 0.905 to 0.278 mg/g for PW2. Similar observations were found in the literature, , which might be attributed to the overcrowding phenomena between available adsorption sites and adsorbates. For the same initial concentration, more adsorbent dosage would dilute the contribution of the individual adsorbents.…”

Comparative study of Cr(VI) removal by bio-waste adsorbents: equilibrium, kinetics, and thermodynamic

“…In recent times, many researchers have achieved the sufficient elimination of Cr(VI) from wastewater, applying natural biomasses such as rice straw (Gao et al 2008), Sterculia guttata shell (Rangabhashiyam and Selvaraju 2015), Gulmohar's fruit shell (Prasad and Abdullah 2010), fish scales and egg shells (Bamukyaye and Wanasolo 2017), activated carbon derived from Leucaena leucocephala (Malwade et al 2016), mangrove leaf powder (Sathish et al 2015), garlic stem and horse chestnut shell (Parlayici and Pehlivan 2015), Juniperus procera sawdust, avocado kernel seeds and papaya peels (Mekonnen et al 2015), and longan seed (Yang et al 2015). The economic price of these adsorbents is insignificantly correlated to the price of ion-exchange resins or activated carbon.…”

Ion-imprinted modified molecular sieves show the efficient selective adsorption of chromium(vi) from aqueous solutions

“…Traditional adsorbents include bio-adsorbents, magnetic nanocomposites, activated carbons, and chelating resin. [10][11][12][13] However, these adsorbents have shortcomings such as sensitive to pH, low specic surface area, poor adsorption capacity, and low selectivity. Metal organic frameworks (MOFs) have attracted extensive attention as adsorbents for the removal of toxic metal ions due to their advantages such as large pore volume, superior adsorption capacity and easy modication.…”