Formation of improved activated carbons from sugarcane bagasse as environmental materials for adsorption of phenolic pollutants

Abstract

Phenolic pollutants are very toxic and their removal from aquatic resources is very important. Adsorption by activated carbon, AC, is the best method for removal of phenols from solutions. However, the high cost of AC and difficulty of its regeneration after phenol adsorption puts high demand on low price AC materials. Therefore, sugarcane bagasse as a sustainable, bulky and fibrous biomass was selected for the purpose of low-price AC formation for phenols adsorption. Sugarcane bagasse derived activated carbon, BAC, was achieved via an environmental thermo-chemical activation process using ZnCl 2 followed by pyrolysis at different temperatures (400-600 °C). The formed BAC materials were characterized by elemental analysis, simultaneous TGA-DTA, ATR-FTIR, XRD, Raman spectroscopy, SEM, and nitrogen adsorption/desorption techniques. The BAC materials showed several enhanced characteristics including extra high specific surface area (up to 2046 m 2 /g), improved meso-/microporosity dual system and nanostructured graphitic-like structure composed of few graphene layers. Adsorption removal of phenol as an industrial waste pollutant was investigated from solutions of wide range of concentrations (50-1000 mg/L). The adsorption processes were characterized by (L2) class of adsorption isotherm, Langmuir isotherm model, physical-adsorption thermochemical parameters and pseudo-second-order kinetics. Adsorptions of two other substituted phenols (resorcinol and pyrogallol) were investigated. The adsorption capacity was increased with increasing of intramolecular bonding of the adsorbate in the order of phenol < resorcinol < pyrogallol. The present results emphasized the versatility of the formed BACs as environmentally sustainable adsorbent for phenolic pollutants.

Experimental Investigation and Thermodynamic Analysis of Coconut-Shell-Derived Activated Carbon for CO2-Based Advanced Adsorption Cooling Systems

“…The figure shows that two major weak peaks are observed at 24° and 44° at (009) and (104) planes, corresponding to the presence of graphite lattice with a low graphitization degree and amorphous nature of the CSAC . The two broad peaks confirm that the CSAC is organized as graphite micro crystallites with graphene layers, and the absence of any strong peaks confirms that the CSAC is free from impurities comprising mineral oxides and crystalline carbons. , …”

Coupling behavior and enhancement mechanism of porous structure, graphite microcrystals, and oxygen-containing groups of activated biochar for the adsorption of phenol

“…Two parallel controls were set up for each AB sample. 28 The conical flasks were placed in a thermostatic shaker at a speed of 150 r min −1 and a temperature of 25 °C for the adsorption test; then, the samples were taken after 4 h of shaking. The concentration of the remaining pollutants in the wastewater was measured using a Shimadzu UH-5300 UV spectrophotometer in Japan at a wavelength of 270 nm, and the unit adsorption amount was calculated.…”

Adsorption Behaviors and Mechanism of Phenol and Catechol in Wastewater by Magnetic Graphene Oxides: A Comprehensive Study Based on Adsorption Experiments, Mathematical Models, and Molecular Simulations

“…According to the difference of phenol concentration, it can be generally divided into high-concentration wastewater containing phenol (more than 1000 mg/L), medium-concentration wastewater containing phenol (5–500 mg/L), and low-concentration wastewater containing phenol for targeted treatment. For the middle- and high-concentration wastewater containing phenol, extraction, stripping, chemical precipitation, and other methods are usually used for the recovery and utilization of phenolic compounds. , However, due to the low phenol concentration, poor recovery economy, and large relative amount, the low-phenol wastewater is generally treated by catalytic degradation, biodegradation, adsorption, and other methods. − Because the chemical structure of phenolic compounds is difficult to degrade, the catalytic degradation and biodegradation methods generally need to go through multilevel treatment to complete, and the economic cost increases significantly with the extension of the treatment process. , As one of the most commonly used wastewater treatment methods, the adsorption method is also used in the treatment of phenol-containing wastewater. , At present, activated carbon, macroporous resin, and new carbon materials are also investigated for the adsorption and removal of phenolic compounds in wastewater. − …”