Efficient removal of hexavalent chromium from aqueous solutions using autohydrolyzed Scots Pine (Pinus Sylvestris) sawdust as adsorbent

Abstract

In this work, a low-cost lignocellulosic adsorbent with high biosorption capacity is proposed, suitable for the efficient removal of hexavalent chromium from water and wastewater media. The adsorbent was produced by autohydrolyzing Scots Pine (Pinus Sylvestris) sawdust. The effect of the autohydrolysis conditions, i.e., pretreatment time and temperature, on hexavalent chromium biosorption was investigated using energy-dispersive X-ray spectroscopy (EDS) and UV-visible spectrophotometry. The Freundlich, Langmuir, Sips, Radke-Prausnitz, Modified Radke-Prausnitz, Tóth, UNILAN, Temkin and DubininRadushkevich adsorption capacities and the rate constant values for pseudo-first-and pseudo-second-order kinetics indicated that the autohydrolyzed material exhibits significantly enhanced hexavalent chromium adsorption properties comparing with the untreated sawdust. The Freundlich's adsorption capacity K F increased from 2.276 to 8.928 (mg g -1 )(L mg -1 ) 1/n , and the amount of hexavalent chromium adsorbed at saturation (Langmuir constant q m ) increased from 87.4 to 345.9 mg g -1 , indicating that autohydrolysis treatment at 240°C for 50 min optimizes the adsorption behavior of the lignocellulosic material.

Kinetic and morphology study of alginate-vineyard pruning waste biocomposite vs. non modified vineyard pruning waste for dye removal

“…In particular, the increasing costs of conventional adsorbents certainly make lignocellulosic-based materials, composed by natural polymers, one of the most attractive bioadsorbents for wastewater treatment (Sharma and Rajesh, 2014;Kumar et al, 2014). Different studies have demonstrated that lignocellulosic-based polymers have exceptional removal capabilities for certain pollutants such as dyes and metal ions as compared to other low-cost adsorbents and commercial activated carbons (Batzias et al, 2009;Rosas-Castor et al, 2014;Sidiras et al, 2013;Velazquez-Jimenez et al, 2013). Thus, cellulose-based biocomposites, has been widely used in wastewater purification due to its good biocompatibility, and excellent handling, which can be easily formulated into spheres, membranes and hollow fibres.…”

Modified Biomass for Pollution Cleaning Under the Frames of Biorefinery and Sustainable Circular Bioeconomy

“…The moisture content of the material was 8-9% w/w. After screening, the particle sizes isolated were 1-2 mm for sawdust, 1-2 cm for straw and 424 cm for straw scale up [18,19].…”

Remediation of heavy metal contaminated ecosystem: an overview on technology advancement

“…Lignin is the third major component of the wood cell wall and it is built up from the phenylpropane nucleus; an aromatic ring with a three carbon side chain, which is promptly available to interact with cationic metal ions (Fatemeh et al 2008). Sidiras et al (2013) have used autohydrolyzing Scots Pine (Pinus Sylvestris) sawdust for removing hexavalent chromium from water and wastewater media. Singh and Prasad (2013b) have also reported that application of natural products such as FYM, SD and RH in Cd-contaminated soil reduced the level of Cd by 36 % under FYM, 23 % under RH and 14 % under SD amended soil.…”