Selective Recovery of Phenolic Derivatives Through the Technique of Liquid Membranes

Abstract

In the present paper we studied the competitive transport of p-nitrophenol (pNP) and 2,4-dinitrophenol (2,4-dNP) from aqueous media using the technique of liquid membranes. This technique is very efficient, economic and selective when compared to other removal techniques of phenolic derivatives. The paper presents the influence of the sodium carbonate concentration from the stripping phase, the influence of the concentration ratio [2,4-dNP]/[pNP] upon the selectivity of the transport process and some kinetic aspects of the transport of 2,4-dNP in the presence of pNP through bulk liquid membranes.

Performance Evaluation of Bulk Liquid Membrane Technique on p-Nitrophenol Removal from Aqueous Solution

“…p-Nitrophenol (PNP), an important member of nitrophenolic compounds, is generally considered one of the most harmful organic pollutants even at low concentrations, for example, prolonged exposure to p-nitrophenol can cause cyanosis, anemia, liver and kidney disease, abdominal pain and vomiting, urinary tract infections, inflammation of the respiratory system, allergic reaction of skin and eye irritations, as well as blood disorder, methemoglobin formation which is responsible for confusion and unconsciousness. This is why the United States Environmental Protection Agency (US EPA) included PNP on the 126 proprietary pollutants list [1][2][3][4] . This compound can be formed as a result of the reaction of phenolic compounds in the atmosphere in aqueous or gaseous phase.…”

“…This compound can be formed as a result of the reaction of phenolic compounds in the atmosphere in aqueous or gaseous phase. Therefore, to avoid contact with PNP and subsequent damage, wastewater containing PNP must be severely treated before being discharged to the natural water body 1,5 .…”

“…It is widely used to darken leather. It can also be found in human and animal waste, and in the decomposition of organic matter 1,[3][4][5] .…”

“…There are many investigations and several treatment methods to remove nitrophenols such as: adsorption [2][3][4] , microbiological degradation or biological treatment 6,7 , chemical oxidation 8 , electrochemical treatment 9 , reverse osmosis 10 , photocatalytic 11 and sonocatalytic 12 degradation and membrane separation 1,13 . The disadvantage of adsorption is that it costly because activated carbon is expensive and difficult to regenerate due to chemisorption of PNP.…”

“…The disadvantage of adsorption is that it costly because activated carbon is expensive and difficult to regenerate due to chemisorption of PNP. Chemical oxidation requires a large amount of oxidizing agent under severe operating conditions and with the risk of incomplete oxidation, resulting in a more toxic product 1,14 . Also, biological treatment is unsuitable for wastewater with high phenol compound concentrations, such as petrochemical, refinery and pharmaceutical operations 14 , because the complexity of some organic substrates in these wastewaters reduces their biodegradability, and of course, some of them are hardly degraded 15 .…”