Preparation of amino-functionalized magnetic biochar with excellent adsorption performance for Cr(VI) by a mild one-step hydrothermal method from peanut hull

Application of biochar-based materials in environmental remediation: from multi-level structures to specific devices

“…5b). Several popular methods including co-precipitation (Chen et al 2011), thermal decomposition and/or reduction (Chen et al 2011;Haham et al 2015;, and hydrothermal synthesis (Cai et al 2019;Frohlich et al 2019;Zhang et al 2018a) techniques can all be directed at the synthesis of high-quality magnetic biochars. For example, different from pre-treatment (co-precipitation of biomass and iron ions) and subsequently pyrolysis, Han et al (2015) employed a post-treatment by precipitation biochar with FeSO 4 and FeCl 3 under base condition to precipitate the iron hydroxides on biochar, and biochar with magnetic iron oxides was obtained by following rinsing and drying processes.…”

“…This characteristic potentially endows magnetic biochar to be directly used in pollutant removal from aqueous solution rather than worrying the leaching of biochar particles that may lead to secondary pollution (Li et al 2020;Yi et al 2020). A wide range of pollutants can be removed through sorption by magnetic biochar, such as inorganic anions (Chen et al 2011;Jung et al 2017), heavy metals (Cai et al 2019;Wang et al 2015c;Wu et al 2018;Yap et al 2017), and organic pollutants (Frohlich et al 2019;. What is more, the introduction of magnetic components (nZVI, nano-Fe 3 O 4 and -FeO) endows or enhances magnetic biochar with catalytic reduction activity for heavy metals (Liu et al 2019b;Zhong et al 2018) and degradation activity for organic contaminants (Chen et al 2017a;Cheng et al 2019;Fu et al 2019).…”

“…Considering the special properties of biochar, to minimize environmental transport and the associated risks for safe applications is essential, biochar particles can be functionalized and incorporated into devices or engineered treatment facility. For example, to bring biochar adsorbent to practical application, biochar particles can be assembled as fillers into mixed matrix materials such as 2D membranes or 3D hydrogels/aerogels (Ghaffar et al 2018;He et al 2017;Jiang et al 2019;Liu et al 2019a), endowed magnetic for easy separation from water (Cai et al 2019;Chen et al 2011), as well as used as amendment (substrate) in engineered filtration systems such as constructed wetlands and biofilters Chen 2018, 2020;Mohanty et al 2018;Tang et al 2016;Zhou et al 2017).…”

High-efficiency adsorption and regeneration of methylene blue and aniline onto activated carbon from waste edible fungus residue and its possible mechanism

“…17 These characteristics promoted the use of activated carbon in environmental governance including the chemical, pharmaceutical, food, printing, and dyeing industries. However, traditional activated carbon raw materials are expensive, causing the use of renewable agricultural waste to prepare activated carbon to gain signicant attention, for example, fox nutshell, 4 walnut shell, 18 rattan of Laccosperma secundiorum, 14 peanut husk, 19 corn cob, 20 apricot kernel, 21 pistachio hull, 22 and wodyetia bifurcate. 23 There are two main methods for making activated carbon: physical activation and chemical activation.…”

Removal of Cr(vi) from wastewater by a two-step method of oxalic acid reduction-modified fly ash adsorption

“…Moreover, the cost to remove the Cr precipitate is currently very high. 5 The other method involves the use of biomass adsorbents, such as peanut shells, banana peels, 6,7 and mineral adsorbents, such as bentonite, montmorillonite, and medical stone, to absorb Cr(VI) and reduce its concentration in the wastewater. This method is facile to implement and possesses high adsorption efficiency.…”