摘要：
Batch experiments were conducted to study the ability of activated palm kernel husk carbon (APKHC) to adsorb Pb(II) ions from aqueous solutions. The effects of various operational parameters, such as temperature (25–55°C), pH (1.0–5.0), contact time (0–120 min), and adsorbent dose (0.5–3.5 g/L) were examined. The results suggested that the adsorption of Pb(II) is exothermic and strongly dependent on pH. The optimum pH for Pb(II) removal is 5.0. The Pb(II) uptake by APKHC was fast and reached an equilibrium in 80 min. The Pb(II) removal efficiency increased with increasing APKHC dosage up to 2.0 g/L, and then reached a plateau with approximately 97% of Pb(II) removed. Experimental data were fitted using Langmuir and Freundlich isotherms. The Pb(II) adsorption can be described well by the Langmuir model with a maximum monolayer uptake capacity of 98.04 mg/g. Kinetic study results suggested that the adsorption process proceeded according to the pseudo-second-order kinetic model. In short, APKHC can be used as an effective economical adsorbent for Pb(II) removal.
摘要：
Coconut husk activated carbon (CHAC) was used as an adsorbent to remove hexavalent uranium (U(VI)) from aqueous solutions by adsorption. Batch experiments were conducted to investigate the effects of contact time, pH, initial U(VI) concentration, and adsorbent dosage on U(VI) adsorption. The adsorption process reached an equilibrium state after 150 min. The uptake of U(VI) was highly pH dependent, and the optimum adsorption was at near-neutral pH. High U(VI) removal efficiencies could be achieved by increasing CHAC dosages. The uranium adsorption capacity increased with increasing initial U(VI) concentrations. Above a certain point, any further increase in initial U(VI) concentration produced no significant change in uranium adsorption capacity. Langmuir and Freundlich models were employed to describe the adsorption isotherm of U(VI) by CHAC. The Langmuir model fitted the equilibrium data better than the Freundlich isotherm. The maximum U(VI) adsorption capacity of CHAC was 6.67 mg/g. Kinetics data were also examined in terms of adsorption kinetics using pseudo-first-order and pseudo-second-order kinetic models. The results suggested that the adsorption process followed the pseudo-second-order kinetics well. In summary, CHAC had significant potential for the removal of U(VI) from aqueous solutions.
作者机构：
[李薇; 张春华; 匡云飞; 许金生; 陈满生; 易正戟] Department of Chemistry and Materials Science, Key Laboratory of Functional Organometallic Materials of Hengyang Normal University, Hengyang, Hunan 421008, China
通讯机构：
[Xu, J.-S.] D;Department of Chemistry and Materials Science, China
摘要：
Two Co(II) complexes, [Co(INAIP)(dib)]·4H2O and [Co(INAIP)(phen)(H2O)]·H2O have been synthesized by the reaction of 5-(isonicotinamido)isophthalic acid (H2INAIP) and CoSO4·7H2O, as well as N-donor ligands, namely 1,4-di(1-imidazolyl)benzene (dib) and 1,10-phenanthroline (phen) under hydrothermal conditions. Single-crystal X-ray diffraction analysis indicates that [Co(INAIP)(dib)]·4H2O has a two-dimensional (2D) double-layer network structure with a (4, 4) topology, while [Co(INAIP)(phen)(H2O)]·H2O displays a one-dimensional chain structure, extending to a 2D net through the π–π interactions. In addition, the photoluminescence and degradation of methyl orange in a Fenton-like process using the complexes as catalysts were investigated.
摘要：
Activated palm kernel shell carbon (APKSC) was used to remove U(VI) from aqueous solutions in a batch system. The adsorption kinetics, isotherms, and effects of various parameters, such as temperature, contact time, solution pH, adsorbent dosage, and initial U(VI) concentration on the U(VI) adsorption process were studied. Equilibrium was reached after 120 min in the range of studied U(VI) concentrations and temperatures. U(VI) uptake was insignificantly affected by temperature, but was highly pH dependent, and the optimum pH for removal was 5.5. U(VI) removal efficiency increased with the increasing adsorbent dosage. U(VI) sorption capacity increased with increasing initial U(VI) concentration; any further increases in initial U(VI) concentration above a certain point caused insignificant changes in U(VI) sorption capacity. Isotherm data could be described by the Langmuir isotherm model with a maximum U(VI) adsorption capacity of 51.81 mg/g. Kinetic data were fitted to pseudo-first-order and pseudo-second-order equations, which suggested that the U(VI) adsorption onto APKSC was better reproduced by the pseudo-second-order model rather than pseudo-first-order model. Our results indicated that APKSC might be used as a cheap adsorbent in the treatment of uranium-containing wastewater.
