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Highlights • ACHC with abundant amino, hydroxyl and carboxylate groups was prepared successfully. • ACHC can remove efficiently and rapidly MB and Cu(II) from aqueous solution. • The surface chelation was mainly contribute to Cu(II) adsorption. • π-π interaction, hydrogen bond and electrostatic attraction dominated MB adsorption. Abstract The polyaminocarboxylated modified hydrochar (ACHC) was synthesized to introduce abundant amino, hydroxyl and carboxylate multifunctional groups onto the surface of hydrochar by etherification, amination and carboxylated reaction. The ACHC was systematically characterized and used to evaluate adsorption properties of Cu(II) and methylene blue (MB) by batch sorption tests. The adsorption process toward Cu(II) and MB by ACHC obeyed the pseudo-second-order kinetic model and Langmuir model. Characteristic analysis indicated the surface chelation was mainly contribute to Cu(II) adsorption by large amounts of amino and carboxylate groups while π-π interaction, hydrogen bonding and electrostatic attraction dominated MB adsorption. The maximum adsorption capacities of ACHC were 140.65 and 1238.66 mg·g−1 for Cu(II) and MB at 303 K, respectively. Approximately 97% of the adsorptive uptakes for two pollutants were removed within merely 5 min for kinetic experiment. Competitive adsorption of Cu(II) and MB, and treatment of electroplating wastewater by ACHC were also investigated. [ABSTRACT FROM AUTHOR]

Hydrochar produced from agricultural and forestry wastes and its application into the environment are very attractive. Herein, a high-efficiency dithiocarbamate-modified hydrochar (DTHC) was prepared successfully and then applied to eliminate Pb(II) from aqueous solutions. DTHC was characterized by various techniques. It was found that dithiocarbamate and amine groups were successfully grafted onto the surface of hydrochar. The surface area of DTHC was 7.94 m 2 ·g -1 , which was four folds less than pristine hydrochar (31.60 m 2 ·g -1 ), but its adsorption capacity obviously increased. Adsorption experiments showed that the Pb(II) adsorption process onto DTHC well accorded with pseudo-2nd-order kinetics and Langmuir isotherms. The highest Pb(II) uptake by DTHC at 293 K determined from the Langmuir model was 151.51 mg·g -1 . Fourier transform infrared spectra and X-ray photoelectron spectroscopy verified that dithiocarbamate, carboxylate, amine and sulfonate groups all facilitated the Pb(II) adsorption. The adsorption mechanism was ascribed to the inner-sphere surface complexation of Pb(II) by these groups and to the ion exchange between Pb(II) and Na(I). Thus, DTHC is an effective adsorbent for Pb(II) removal from water., Competing Interests: Declaration of competing interest We declare that we do not have any commercial or associative interest that represents a conflict of interest in connection with the work submitted., (Copyright © 2020 Elsevier B.V. All rights reserved.)

In the title compound, [Ni(C(6)H(3)ClNO(2))(2)(H(2)O)(4)]·4H(2)O, the Ni(II) ion is located on an inversion centre and is octa-hedrally coordinated by four O atoms from four water mol-ecules in the equatorial plane and two O atoms of two 6-chloro-3-carboxyl-ate ligands in axial positions. There are also four lattice water molecules present. The organic ligands are bound to the Ni(II) ion in a monodentate manner through a carboxyl-ate O atom. There is one strong intra-molecular O-H⋯O hydrogen bond and six inter-molecular O-H⋯O and O-H⋯N hydrogen-bonding inter-actions in the packing, resulting in a complex three-dimensional network structure.