X-ray absorption as an alternative method to determine the exhausting degree of activated carbon layers in water treatment system for medical services

Chemical Regeneration of Activated Carbon Used in A Water Treatment System for Medical Services

“…These properties promoted the use of AC in all kinds of industries such as: food, chemical processes, metallurgy, energy, water treatment and medical services [1,2]. In Cuba, granular activated carbon (GAC) is commonly used in hospitals for HClO, ClO -(forming free chlorine) and/or chloramines removal after the addition of chlorinated compounds to the water city supply for water disinfection [3,4]. As many accidents have been reported caused by these contaminants towards patient exposure [3,5,6] the GAC is thus essential in hemodialysis.…”

“…In this regard GAC regeneration has an important role in its correct management for the hospitals. Correct management of GAC constitutes four main steps: (1) Characterization, (2) Exploitation, (3) Regeneration and (4) Reuse [2,3]. Therefore, the regeneration of the GAC cannot only preserve the natural resources and reduce secondary pollution, but can also bring economic profit [2].…”

“…The hydrolysis of the molecular chlorine results in the formation of HClO and/or ClOdepending on the pH of the solution [3]. The formed HClO/ClOin the treated water is reduced by the GAC into a non-oxidative chloride ion (Cl -) resulting in a GAC matrix deterioration (with possible removal of some organic fraction) as a result of the in situ formation of oxygenated carbon functionalities (hydroxyl, carbonyl and carboxyl groups) in the carbonaceous matrix [3].…”

“…These oxygenated carbon functionalities have the potential to act as complexing sites at the GAC surface with the inorganic ions present in the used water [3]. Recently, formed complexes (Cacarboxylates) have been reported in GAC adsorbers used in hospitals [3].…”

“…These oxygenated carbon functionalities have the potential to act as complexing sites at the GAC surface with the inorganic ions present in the used water [3]. Recently, formed complexes (Cacarboxylates) have been reported in GAC adsorbers used in hospitals [3]. The formation of these complexes at the GAC surface together with the GAC matrix degradation due to HClO oxidation initiates an exhaustion process of this GAC, reducing its adsorption capacity towards inorganic ions [3] and decreasing its dechlorinating capacity (redox reactions), and thus affecting the reliability of the water treatment system and therefore the hemodialysis therapy itself.…”