Fractionational and structural characterization of lignin and its modification as biosorbents for efficient removal of chromium from wastewater: a review

Abstract

The removal of chromium (Cr) from wastewater by various adsorbents has been investigated. As compared with the commercial activated carbon, the biosorbents with inexpensive and high adsorption capacities are developed from lignocellulosic wastes. Lignin, existing in lignocellulosic biomass, is the second most abundant resource in nature. Recently, lignin-based bio-sorbents were served as an advanced novel material for the metal ions and dye adsorption from wastewater. It has showed several advantages in the wastewater treatments because of the lowcost, high adsorption capacity, easy recover, and possibility of metal recovery. In this review, the isolation of lignin from lignocellulosic biomass was summarized, and the structural characteristics of lignin were comparably analyzed. The modification of lignin was performed to obtain a large surface area, strong binding-site, and high and quick adsorption properties of lignin-based adsorption materials. The adsorption efficiency of Cr ions was found to be strongly dependent on the pH of the wastewater. To further illustrate the adsorption process, the structural changes and the interactions between the metal ions and the functional groups of the lignin-based biosorbents in the adsorption process should be further investigated. Once the cost-effective and high-efficiency modification techniques are developed, lignin-based adsorbents can be expected to be the most suitable alternatives for Cr ions removal from wastewater in industry.

Characterization of Lignin Structures in Phyllostachys edulis (Moso Bamboo) at Different Ages

“…The physical and chemical properties of lignin produced by content changes of nonpolymeric alcohols in different plant sources are quite different, which is one of the obstacles in industrialization. In the process of plant lignification, the formation of lignin monomer from cross-linking to each other to form lignin macromolecules adds further complexity to the lignin structure [15]. Therefore, the structural complexity of lignin of different species is also an important constraint.…”

Greener Routes to Biomass Waste Valorization: Lignin Transformation Through Electrocatalysis for Renewable Chemicals and Fuels Production

“…[139] They demonstrated that H 2 O 2 production can be increasedb yi ncreasing O 2 production at the anode,w hich is enhanced by increased current density. [139] This increasei nH 2…”

“…After separation, lignin is typicallyc ombusted as al ow-grade fuel for its energy value, and for the recovery of pretreatmentc hemicals. [2][3][4] Lignin is the second most abundant biopolymer after cellulose. It is estimated that over 170 billion metric tons of biomass could be annually harvested worldwide, [5] of whichl ignin constitutes 10-25 %.…”

“…Conversely, lignin is comparatively underutilized. After separation, lignin is typically combusted as a low‐grade fuel for its energy value, and for the recovery of pretreatment chemicals …”

Bahaya Kromium Hexavalen (Cr VI) Pada Kulit Dan Produk Kulit Samak Krom Serta Upaya Pencegahannya

“…Dalam beberapa tahun terakhir, limbah cair yang mengandung ion logam berat telah menyebabkan masalah lingkungan yang serius, terutama yang berkaitan dengan pencemaran tanah (Oyekanmi, et al, 2019a;Oyekanmi, et al, 2019). Lebih memprihatinkan adalah bahwa Cr 3+ yang dibuang berpotensi teroksidasi menjadi kromium heksavalen berbahaya (Cr 6+ ), yang merupakan ancaman bagi kesehatan manusia (Wang, et al, 2019). Keberadaan kromium heksavalen dalam kulit tersamak juga membahayakan kesehatan manusia.…”