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The nickel removal of the system Ni(II)-NH3-CO2-SO2-H2O was studied by electrocoagulation in a cylindrical reactor with agitation, of 25 L of useful capacity and two pair of Al/Al electrodes. Effluentliquor from the distillation process of the nickelproducer plant in Punta Gorda, Cuba, was processed with nickel concentration from 300 to 652 mg/L, at a current density of 8,3 mA/cm2, 60 °C and pH 8,64 (+/-0,033). An average removal efficiency of 99,65 (+/-0,07) % was obtained, an equilibrium concentration less than 2 mg/L and an adsorption capacity between 3342 and 7264 mg/g. According to the kinetic and equilibrium analysis, it is considered that the process is probably under the control of the resistance of the chemical reaction mechanisms and its autocatalytic contribution. The operation costs for electrical energyand electrode consumption were between 11,122 y 16,022 CUP/kg of removed nickel and the specific energy consumption of 1,709 to 2,342 kW-h/kg of Al. [ABSTRACT FROM AUTHOR]

Adsorption is one of the methods used to remove contamination in liquid waste. The purpose of this research is characterizing the removal of Cu (II) and Ni (II) ions using zeolite in its natural state from the central zone of Cuba and applying the adsorption method with modeled solutions, in a pH range between four and six units. The adsorption properties of the mineral were evaluated and the adsorption parameters of Cu (II) and Ni (II) ions were determined. The kinetic study showed that the pseudo-second - order kinetic mode describes the rate of adsorption of both contaminants and the Freundlich adsorption isothermal equation is the best fit for both ions. The maximum adsorption capacity of the natural zeolite was 22.148 mg/g and 90.09 mg/g for Cu (II) and Ni (II) ions, respectively. [ABSTRACT FROM AUTHOR]

At the moment one of the main environmental problems is the existence of pollutants in the bodies of water due to the emission of polluted efluentes mainly for heavy metals. These compounds are characterized to be persistent and not biodegradable, of there the importance of their elimination. The interior part of the bay of Santiago from Cuba is the polluted due to the characteristic hydro geographical that presents. In this study investigative works related with the bioadsorventes no conventional employees were revised at world level for the mitigation of heavy metals, which possess advantages on the conventional ones to be highly available, to be of low costs and degradable. Of the bibliographical revision it could be proven that among the no conventional methods they are the biopolímeros application, the biorremediación and the use of agroindustrial residuals. The search was focused in the agroindustrial residuals to be the most abundant under our conditions. Of the employees the shells of Yucca are with more tendencies, of banana, of citric, it erases it of coffee, egg shell and the cane of sugar. The present work has as objective to present a revision of the main bioadsorbentes of low costs more employees at world level in the mitigation of the heavy metals, of there the selection of the most feasible for its use in the waters of the bay of Santiago from Cuba under the current conditions. [ABSTRACT FROM AUTHOR]

A technological purification procedure for obtaining a Cuban activated carbon is described. Characteristics of the obtained charcoal are similar to those corresponding to imported materials according to the following standards: United States Pharmacopeia 30, British Pharmacopeia (BP) and the Cuban National Standards. Results obtained during purification of Cuban activated carbon (M1) were compared with two imported materials as reference: USPXX Norit and RPCh. The first of these materials have been used during more than 20 years in the Cuban National Health System in cases of medical poisoning and as raw material in the preparation of coal and pepsin tablets for digestive disorders. Besides, the following comparative aspects were considered: physical chemical characterization, atomic absorption and ACP -AES analysis and specific adsorption: iodine number, molasses percent, methylene blue and strychnine. Technological procedure consists mainly of an acid leaching-base without heating, including filtration stages and very simple washings waters, as also recirculation of liquors of the process. Comparison results were statistically processed by a multiple range test and differences obtained were not significant (α = 0,05 %). It is an indication of the effectiveness of the purification procedure. Economic feasibility study offers favourable results in the indexes considered: NPV, IRR, EE, ROI, estimated price and production cost. All these results as a whole support the possibility of having in Cuba with a process and as a result of it, with a material of sufficient quality to replace imports in the short term. [ABSTRACT FROM AUTHOR]