Abstract: Magnetized hydrochar for the adsorption of cadmium and a method of synthesizing magnetized hydrochar from microalgal biomass are provided. The magnetized hydrochar may be synthesized by subjecting a microalgal biomass to a hydrothermal carbonization (HTC) reaction to produce hydrochar, chemically activating the hydrochar with H2O2, and magnetizing the activated hydrochar through coprecipitation. The microalgal biomass may be selected from Chlorella vulgaris FR751187 or Scenedesmus obliquus GU732418. The resulting mHC may be used to adsorb cadmium ions from an aqueous environment, including but not limited to waste effluent.

Abstract: A melamine-formaldehyde derived porous carbon adsorbent may be prepared from melamine-formaldehyde derived porous carbon disposable products. The melamine-formaldehyde derived porous carbon effectively removes organic pollutants from aqueous media. Parameters of contact time, solution pH, initial adsorbate concentration and desorption rate affect efficacy. Adsorption capacities of exemplary melamine-formaldehyde derived porous carbon for MG and MB dyes at 298 K were up to 25 mg/g and 35 mg/g, respectively.

Abstract: A method of producing hydrochar from jackfruit peel biomass includes hydrothermal carbonization of jackfruit peel biomass by autoclaving at 150° C.-250 ° C. for about 3 hours to produce a hydrochar. The hydrochar can be activated by treatment with phosphoric acid (H3PO4), hydrogen peroxide (H2O2), or a combination thereof. The hydrochar produced according to the method is particularly effective at removing azo-dyes, and specifically methylene blue, from aqueous solutions such as industrial waste water.

Abstract: A method of producing hydrochar from jackfruit peel biomass includes hydrothermal carbonization of jackfruit peel biomass by autoclaving at 150° C.-250° C. for about 3 hours to produce a hydrochar. The hydrochar can be activated by treatment with phosphoric acid (H3PO4), hydrogen peroxide (H2O2), or a combination thereof. The hydrochar produced according to the method is particularly effective at removing azo-dyes, and specifically methylene blue, from aqueous solutions such as industrial waste water.

Abstract: A method of producing hydrochar from jackfruit peel biomass includes hydrothermal carbonization of jackfruit peel biomass by autoclaving at 150° C.-250 ° C. for about 3 hours to produce a hydrochar. The hydrochar can be activated by treatment with phosphoric acid (H3PO4), hydrogen peroxide (H2O2), or a combination thereof. The hydrochar produced according to the method is particularly effective at removing azo-dyes, and specifically methylene blue, from aqueous solutions such as industrial waste water.

Abstract: A method of producing hydrochar from jackfruit peel biomass includes hydrothermal carbonization of jackfruit peel biomass by autoclaving at 150° C.-250° C. for about 3 hours to produce a hydrochar. The hydrochar can be activated by treatment with phosphoric acid (H3PO4), hydrogen peroxide (H2O2), or a combination thereof. The hydrochar produced according to the method is particularly effective at removing azo-dyes, and specifically methylene blue, from aqueous solutions such as industrial waste water.

Abstract: The magnetic polymer nanocomposite for removal of divalent heavy metal ions from water is magnetic nanocomposite having a core of magnetite (Fe3O4) in a shell of branched polyhydroxystyrene (BHPS), designated as Fe3O4@BHPS. The nanocomposite is synthesized by co-precipitation in alkali solution. Testing showed the nanocomposite reached 93% and 80% Pb(II) and Cd(II) adsorption, respectively, in 30 minutes, attaining equilibrium in 120 minutes. The maximum adsorption capacities of Pb(II) and Cd(II) at 298K were 186.2 and 125 mg/g, respectively. After adsorption, the nanocomposite with the heavy metal(s) adsorbed thereto was easily removed from aqueous solution by application of a magnetic field.

Abstract: Carboxylic functionalized magnetic nanocomposites can include a magnetic compound, such as Fe3O4, that is encapsulated by a plurality of amino organosilane groups. The organosilane groups can include 3-[2-(2-Aminoethylamino)ethylamino] propyl-trimethoxysilane (TAS). At least some of the organosilane groups can have amino and carboxylic acid substituents. The organic pollutants can include malachite green dye. The carboxylic functionalized magnetic nanocomposites can adsorb dye from solution, such as wastewater. The carboxylic functionalized magnetic nanocomposites can be separated from the solution using an external magnetic material.