ADSORPTION

Adsorption



Adsorption

Introduction

Wastewater treatment is a series of physical, chemical and biological processes are aimed at eliminating the physical, chemical and biological agents present in the effluent water for human use. The goal of treatment is to produce clean water (or treated effluent) or reusable in the environment and a solid waste or sludge (also called bio-solids or sludge) suitable for disposal or reuse. It is very common to call waste water treatment to distinguish it from drinking water treatment. The wastewater is generated by residences, institutions and commercial and industrial. These can be treated within the site which are generated (e.g. septic tanks or other means of treatment) or can be picked up and carried through a network of pipes - and eventually bombs - a municipal treatment plant. Efforts to collect and treat domestic wastewater discharge are typically subject to local regulations and standards, state and federal (regulations and controls). Often certain pollutants from industrial sources present in wastewater treatment processes require specialized (Cooney, 1998).

Adsorption is that property which has some substance to lock in certain surface molecules. Industrial adsorbents used are activated carbon and synthetic resins. Addition to its use in treating water and wastewater, the adsorption is used for the recovery of certain organic products (phenols, pesticides, etc.) and metals. Adsorption is a phenomenon that occurs on the surface of a body (Adsorbent) and consists of two separate phases: a solid and fluid. It is a process widely used in purification of gases where the element contaminant that is suspended in the purge gas is retained by the adsorptive element. Adsorption is a physical attachment of molecules on the surface of a solid. This phenomenon is used to "recover" undesirable molecules of fluid (liquid or gaseous) dispersed in a solvent. The setting comes from the establishment, between the solid and molecules, Van Der Waals bonds (electrostatic type bonds of low intensity, with interaction energies between 5 and 40 kJ / mol). Adsorption is a process where a solid is used to remove water soluble substance. In this process the activated carbon is solid. Activated carbon is produced specifically to reach a very large internal surface (500 - 1500 m 2 / g). The large internal surface area makes the charcoal has an ideal adsorption. Activated carbon comes in two variations: powdered activated carbon (PAC) and granular activated carbon (GAC) (Cooney, 1998).

Discussion

Process Description

Water is pumped into a column containing activated carbon; the water leaves the column through a drainage system. The activity of active carbon column depends on the temperature and the nature of the substances. The water passes through the column constantly, resulting in an accumulation of substances in the filter. For that reason the filter needs to be replaced periodically. A used filter can be regenerated in various ways; granular carbon can be regenerated easily oxidized organic matter. The effectiveness of activated carbon decreases by 5-10% after each regeneration. A small portion of active carbon was destroyed during the regeneration process and must be ...