Comparison of natural minerals for treatment of drug pollutant wastewaters by Heterogeneous Fenton process

The drug pollution combined with other environmental pollution agents resulted in the spread of pollution in a local to global scale.1 Gemcitabine hydrochloride as a drug contaminant is an antitumor agent with LD50=500 mg/kg. So, presence little amount of this drug in the water released from hospital effluents to the environment can cause serious and long lasting effects on humans and other creatures.2 This research aimed to present a green, simple, cheap and also efficient method for degradation of drugs and wastewater treatment. Some iron minerals from the nature can be useful catalysts as a source of required iron for the Fenton reaction.3 Production of H2O2 in situ play another main role to present a safe and cost effective treatment method.4, 5 Herein, present study applied heterogeneous Electro-Fenton catalyzed by 5 iron minerals such as Limonite, Hematite, Magnetite, Siderite and Pyrite. In this study, the amount of TOC was investigated for five minerals at certain times. In addition, removal efficiency, reaction rate constants and amount of iron ions produced in the solutions were determined for all mineral catalysts. As a result, pyrite with the maximum amount of rate constant (k = 8 .0. 10-3 min-1) and efficiency of degradation (75%) was the only mineral able to degrade Gemcitabine in aqueous solution considerably in the same condition. The major asset of this study is that using pyrite prevent solution increasing pH during the reaction and hence provide the best condition of acidic pH for Fenton reaction.

Keywords:

Advanced Oxidation Process , heterogeneous Electro-Fenton , iron mineral clays , drug pollutants , wastewater treatment