Preparation of Activated Biochar-Supported Magnetite Composite for Adsorption of Polychlorinated Phenols from Aqueous Solutions

Abstract

For this study, we applied activated biochar (AB) and its composition with magnetite (AB-Fe3O4) as adsorbents for the removal of polychlorophenols in model wastewater. We comprehensively characterized these adsorbents and performed adsorption tests under several experimental parameters. Using FTIR, we confirmed successful synthesis of AB-Fe3O4 composite through cetrimonium bromide surfactant. We conducted adsorption tests using AB and AB-Fe3O4 to treat model wastewater containing polychlorophenols, such as 2,3,4,6-Tetrachlorophenol (TeCP), 2,4,6-Trichlorophenol (TCP), and 2,4-Dichlorophenol (DCP). Results of the isotherm and the kinetic experiments were well adapted to Freundlich’s isotherm model and the pseudo-second-order kinetic model, respectively. Main adsorption mechanisms in this study were attributed to non-covalent, π-electron acceptor–donor interactions and hydrophobic interactions judging from the number of chloride elements in each chlorophenol and its hydrophobic characteristics. We also considered the electrostatic repulsion effect between TeCP and AB, because adsorption performance of TeCP at basic condition was slightly worse than at weak acidic condition. Lastly, AB-Fe3O4 showed high adsorption selectivity of TeCP compared to other persistent organic pollutants (i.e., bisphenol A and sulfamethoxazole) due to hydrophobic interactions. We concluded that AB-Fe3O4 may be used as novel adsorbent for wastewater treatment including toxic and hydrophobic organic pollutants (e.g., TeCP).

Experimental Study on the Optimum Preparation of Bentonite–Steel Slag Composite Particles

“…However, neutralization precipitation requires a large amount of chemical agents, such as neutralizer and flocculent [23,24], which leads to difficulties in solid-liquid separation and high processing costs [25,26]. Besides various adsorbent materials, activated carbon is frequently used for adsorption, but has a low adsorption capacity for heavy metal ions, has high costs, and cannot neutralize acid [27][28][29]. At present, most treatments use a single method, and the treatment effect is poor.…”

Engineered biochar from wood apple shell waste for high-efficient removal of toxic phenolic compounds in wastewater

“…Different agro-waste or other biomass waste added-value materials for the removal of phenol and its derivative compounds contained in aqueous wastewaters have not been thoroughly examined. Therefore, recently, many researchers have focused their efforts on enhancing the adsorption capacity using different carbon-rich adsorbent materials such as activated carbon 20 – 22 , activated carbon fibers 23 , carbon nanocomposites 24 , 25 , activated biochar-supported magnetite composite and activated biochar 26 , 27 , carbon nanotubes 28 , 29 , graphene oxide 30 , 31 , and biochar 9 , 32 to eliminate phenolic contaminants from wastewater. Activated carbon is one of the most widely used sorbents for the adsorption technique 33 .…”

“…The preparation of biochar is based on the pyrolysis of biomass materials, which can be derived from a wide range of algal biomass, poultry litter, forestry waste, activated sewage sludge, and agricultural crop waste raw materials using the thermal process. Biochar has been known to have an efficient uptake capacity, highly abundant, and low-cost sorbent; it has already been used to eradicate heavy metals 44 , 45 and organic contaminants 26 , 31 , 40 , 46 from wastewater. However, many research studies have shown that biochar uptake capacity has been considerably enhanced after modifying chemically or physically mainly due to the increase of the specific surface area, surface functional groups, and pore volume 47 , 48 .…”

“…Among these techniques, adsorption technology is broadly used compared to other approaches owing to its easy operation, economical advantages, and greater efficiency of removing inorganic and organic contaminants on industrial or laboratory scales.Different agro-waste or other biomass waste added-value materials for the removal of phenol and its derivative compounds contained in aqueous wastewaters have not been thoroughly examined. Therefore, recently, many researchers have focused their efforts on enhancing the adsorption capacity using different carbon-rich adsorbent materials such as activated carbon [20][21][22] , activated carbon fibers 23 , carbon nanocomposites 24,25 , activated biochar-supported magnetite composite and activated biochar 26,27 , carbon nanotubes 28,29 , graphene oxide 30,31 , and biochar 9,32 to eliminate phenolic contaminants from wastewater.…”

Ultrasound-Assisted Preparation of Chitosan/Nano-Activated Carbon Composite Beads Aminated with (3-Aminopropyl)Triethoxysilane for Adsorption of Acetaminophen from Aqueous Solutions

“…The adsorption process is a low-cost (in terms of design and operation) physical process that can separate toxic contaminants and thus avert the generation of biologically active by-products [5,6]. Moreover, cheap adsorbents or highly engineered ones with outstanding properties are being developed for pollutant removal [7,8].…”