Stability and removal of spironolactone from wastewater

Abstract

Stability and removal of spironolactone (SP) from wastewater produced at Al-Quds University Campus were investigated. Kinetic studies on both pure water and wastewater coming from secondary treatment (activated sludge) demonstrated that the potassiumsparing diuretic (water pill), spironolactone, underwent degradation to its hydrolytic derivative, canrenone, in both media. The firstorder hydrolysis rate of SP in activated sludge at 25 C (3.80 £ 10¡5 s ¡1 ) was about 49-fold larger than in pure water (7.4 £ 10¡7 s ¡1 ). The overall performance of the wastewater treatment plant (WWTP) installed in the University Campus was assessed showing that more than 90% of spiked SP was removed together with its newly identified metabolites. In order to look for a technology to supplement or replace ultra-filtration membranes, the effectiveness of adsorption and filtration by micelle-clay filters for removing SP was tested in comparison with activated charcoal. Batch adsorption in aqueous suspensions was well described by Langmuir isotherms, showing a better removal by the micelle-clay material. Filtration of SP water solutions by columns filled with a mixture of sand and a micelle-clay complex showed complete removal of the drug at concentrations higher than in sand/activated-charcoal filled filters.