Adsorption of pesticides onto activated carbons from wood composites

A series of activated carbon was produced from particleboard and medium-density fibreboard monoliths, which are waste originated from the industry, and then characterized and evaluated for potential application for phenoxyacetic acids removals, such 2,4-dichlorophenoxyacetic acid (2,4-D), 2-methyl-4-chlorophenoxy acetic acid (MCPA) and 3-(3,4-dichlorophenyl)-1,1-dimethylurea (diuron), from the liquid phase. All AC retain the shape of the precursor, and displays a microporous structure well-developed, reaching 0.58 cm 3 g -1. The adsorption isotherms for three pesticides were obtained in the optimal conditions and the AC with high superficial area and micropore volume exhibited better performance, allowing to state that, this AC could be a great substitute of those habitually used for this purpose. The pesticides adsorption data were linearized using the Langmuir and Freundlich equation, being the first a very good fit to the experimental data

Adsorption of bisphenol A by granular activated carbon prepared with different silicates as binders

Nowadays, the emerging pollutants, such as bisphenol A, are object of increased attention by the citizens and the sectors of industry and academia, as a result of the problems they cause, particularly at the health level. In this study, a set of granulated samples was prepared from a commercial powdered activated carbon, aiming its application in the removal of bisphenol A via the adsorption process. The granulation allowed to obtain granulated adsorbents with higher adsorption capacity (37.0–54.8 mg/g) than the original activated carbon (32.2 mg/g). The samples were structurally and chemically characterised using scanning electron microscopy, X-ray diffraction, nitrogen adsorption at 77 K, Fourier-transformed infrared spectroscopy, point of zero charge and energy-dispersive X-ray spectroscopy techniques. The bisphenol A adsorption tests are carried out in kinetic and equilibrium modes, involving variables such as mass, pH and temperature. The results show that, using different commercial silica binders, it was possible to prepare mechanical, dimensional, chemical and structurally stable granulated adsorbents with a good capacity for bisphenol A adsorption, widening the potential and range of application for these materials

Cuantificación porcentual de los daños existentes en los revestimientos interiores de las viviendas españolas

Internal coatings are among those construction units which experience the most interaction with users, given their proximity to them. This research focuses on determining the most usual damages in tiling, cement renders, plasters, suspended ceilings and indoor flooring from all of Spain, as per the requirements indicated by the users. In addition, the causes of these deficiencies are also found, as well as their percentage according to the type of construction they are found in (flats or houses). From the data used, the most typical groups of damages are indicated, as well as a procedure to determine the probability of future damages, according to a weighted matrix classifying the correspondence between 4 descriptors. The knowledge of these results will assist technicians to minimise damages in these types of construction units.Los revestimientos interiores son de las unidades constructivas que más interrelación tienen con los usuarios, dada su cercanía de uso con éstos. Esta investigación se centra en la determinación de los daños más usuales en los alicatados, enfoscados, guarnecidos, falsos techos y solados interiores, obtenidos en el conjunto de España a partir de los requerimientos presentados por los usuarios. Se determinan también cuáles son los orígenes que motivan estas deficiencias, así como la presencia que tienen las mismas en función del formato constructivo en donde tienen lugar (viviendas en bloque o unifamiliares). A partir de los datos manejados se presentan los grupos de daños más característicos, así como un procedimiento para determinar la probabilidad ante futuros requerimientos, en función de una matriz ponderada que clasifica la correspondencia entre los 4 descriptores manejados. El conocimiento de los resultados obtenidos ayudará a los técnicos a minimizar los daños en estas unidades constructivas

Modification and Optimization of Activated Carbons for Phenolic Compounds Removal

Phenols are generally considered to be one of the important organic pollutants discharged into the environment causing unpleasant taste and odour of drinking water. Development of inexpensive adsorbents from industrial wastes for the treatment of wastewaters is an important area in environmental sciences. For the phenolic compounds removal, it appears that the pH of the solution, the real surface area of the solid, and functional groups play a major role. The objective of this study was to screen various adsorbents for potential application for the removal of phenolic compounds for drinking water concentration range. The adsorbents used in this study were AC prepared from recycled PET and AC prepared from cork submitted to a reduction post treatment

Using Waste Recycled PET for AC Production for Pesticides Removals from Aqueous Solutions

Over the last decades the literature has shown the possibility of producing activated carbons (AC) from a wide variety of raw materials and to use them as one of the most environment-friendly solutions for waste disposal. Additionally it has been shown that the adsorption of pollutants from different media by AC is one of the most efficient techniques for remediating or solving this type of problem. In this context, the presence of pesticides in water can cause serious problems in the environment and to human health; their removal from wastewaters is a crucial concern. The work presented here focuses these two problematic areas (solid waste reduction and wastewater treatment). The main idea was to develop low cost and efficiently adsorbent materials for hazardous compounds removal from aquatic media, to level admitted in drinking water

Microporosity evaluation of active carbon from polish lignite by the use of ethanol

Microporous activated carbons prepared by KOH chemical activation or steam activation from lignite were characterised by adsorption of N2 at 77 K and CO2 at 298 K. Subsequently, the adsorption of ethanol was carried out and complemented by adsorption of benzene and cyclohexane. The isotherm analysis included application of the αs method using ethanol reference data obtained here by also studying non-porous carbon blacks. The work confirmed that ethanol is an experimentally convenient adsorptive to use and leads to results in overall agreement with those obtained using other probe molecules. Of particular interest was the observation that ethanol can gain access to the whole microporosity even in the case of samples containing constricted micropore entrances

Direct Nitrogen Enrichment of Activated Carbon Produced from Synthetic or Natural Precursor

The specific application of activated carbons (AC) as adsorbents for gases and vapours depends on the properties of pollutants to be removed, but the performance of the AC depends on various properties. If their porosity is the main parameter in gas adsorption, the chemical nature of their surface plays a significant role in liquid phase interactions and in their usefulness as catalyst support materials. Of particularly interest are the AC containing heteroatoms, such as oxygen, hydrogen, phosphorus, sulphur and nitrogen. Generally, the AC containing various nitrogen groups,present more basic character and increased adsorption of acidic agents is expected. These AC found widespread applications as adsorbents for hydrogen sulphide, sulphur dioxide, sulphur and carbon dioxide and as catalysts for selective oxidation of hydrogen sulphide

Modification and Optimization of Activated Carbons for Phenolic Compounds removals

Phenols are generally considered to be one of the important organic pollutants discharged into the environment causing unpleasant taste and odour of drinking water. Development of inexpensive adsorbents from industrial wastes for the treatment of wastewaters is an important area in environmental sciences. For the phenolic compounds removal, it appears that the pH of the solution, the real surface area of the solid, and functional groups play a major role. The objective of this study was to screen various adsorbents for potential application for the removal of phenolic compounds for drinking water concentration range. The adsorbents used in this study were AC prepared from recycled PET and AC prepared from cork submitted to a reduction post treatment

Activated Carbon Post Treatment - Influence on Phenolic Compounds Removal

● AC preparation from different precursors and their modification / optimisation with sodium hydroxide and urea to improve the adsorption capacities for phenolic compounds from the liquid phase. ● Comparative study of the influence of textural and chemical parameters of AC on the liquid phase adsorption

Modification and Optimization of Activated Carbons for Phenolic

Phenolic compounds are generally considered to be one of the important organic pollutants discharged into the environment causing unpleasant taste and odour of drinking water [1,2]. So, removal of phenolics compounds from industrial effluents is required before sewage disposal. The development of inexpensive adsorbents from industrial wastes for the treatment of wastewaters is an important area in environmental sciences. For the phenolic compounds removal, it appears that the pH of the solution, the real surface area of the solid and functional groups play a major role. Adsorption onto activated carbons (AC) is often considered, amongst the methods currently employed to remove inorganic and organic pollutants, from aqueous or gaseous phases, as the most efficient and one of the most economical. A detailed characterization of physical and chemical surface properties of an AC has become one of the most important issues in adsorption technology because it ascertain its suitability for one or more of the application fields