Sorption studies of Cr(VI) from aqueous solution using bio-char as an adsorbent

Abstract

The characteristics of sorption of hexavalent chromium (Cr(VI)) onto bio-char derived from wood chips (spruce, pine, and fir) were evaluated as a function of pH, initial Cr(VI) concentration and bio-char dosage using synthetic wastewater in batch tests. The initial Cr(VI) concentrations were varied between 10 and 500 mg/L to investigate equilibrium, kinetics, and isotherms of the sorption process. About 100% of Cr(VI) was removed at pH 2 with initial Cr(VI) concentration of 10 mg/L using 4 g of bio-char after 5 hours of sorption reaction. The maximum sorption capacity of the bio-char was 1.717 mg/g for an initial Cr(VI) concentration of 500 mg/L after 5 hours. The sorption kinetics of total Cr onto bio-char followed the second-order kinetic model. The Langmuir isotherm model provided the best fit for total Cr sorption onto bio-char. The bio-char used is a co-product of a down draft gasifier that uses the derived syngas to produce electricity. Bio-char as a low cost adsorbent demonstrated promising results for removal of Cr(VI) from aqueous solution. The findings of this study would be useful in designing a filtration unit with bio-char in a full-scale water and wastewater treatment plant for the Cr(VI) removal from contaminated waters.

Preparation of Pd–Ni Nanoparticles Supported on Activated Carbon for Efficient Removal of Basic Blue 3 from Water

“…The dye's concentration was determined based on the calibration curve drawn for a concentration range. The adsorption capacity of adsorbent q t (mg g −1 ) and the removal efficiency were calculated by using Equations ( 1) and ( 2), respectively, according to a comparative study performed [76,77]:…”

“…The Elovich equation was applied to explain some aspects of the adsorption process. A mathematical form of the model can be expressed as [76,77]:…”

“…The q t vs. lnt was plotted and is shown in Figure 6d, and the value of α and β were determined, which are listed in Table 3. The Natarajan and Khalaf equation gives the relationship between the initial dye concentration C 0 and the concertation at a certain time C t [76,77]:…”

Assessment of naproxen adsorption on bone char in aqueous solutions using batch and fixed-bed processes

“…However, this drug is considered as an emerging water pollutant with a high environmental risk [12]. The bone char is a low-cost and high performance carbon-based adsorbent that can be applied for the removal of both organic and inorganic compounds [8,[25][26][27]. To the best of the author's knowledge, this adsorbent has not been used for naproxen adsorption from aqueous solutions.…”

Date Palm (Phoenix Dactylifera L.) Seed Characterization for Biochar Preparation

“…Over the last decade, biochar has been promoted as a low cost adsorbent with high adsorption capacity for organic and non-organic pollutant removal (Ates and Un, 2013). Various types of organic biomass are currently used for biochar production such as wood materials, rice husk, empty fruit bunch, peanut and wheat straw, orange wastes, and olive pomace (Hyder et al, 2014;Claoston et al, 2014;Pellera et al, 2012;Saleh et al, 2014;Chen and Chen 2009;El Hanandeh 2015). The physicochemical properties of biochar are influenced by the feedstock composition and pyrolysis conditions such as pyrolysis temperature and residence time (Downie et al, 2009;Kloss et al, 2012).…”