Photodegradation of rhodamine B dye using a microwave electrodeless UV lamp (MWUVL)

Abstract

The photodegradation of organic dye rhodamine B (RhB) in an aqueous solution was studied using a microwave electrodeless UV lamp (MWUVL). The 185 nm vacuum UV (VUV) intensity of the MWUVL amounted to 12% of the total UV output, about 1.7 times as high as that of the con ventional low-pressure mercury lamp. An acidic condition was preferred for the degradation of RhB. Precipitate was generated during RhB degradation when the initial concentration of RhB solution was above 60 mg · L −1 . For 100 mg · L −1 RhB at pH 4.0, the mass of precipitate produced was nearly half of the initial amount of RhB in the solution after irradi ation for 75 min. The corresponding degradation ratio of RhB reached up to 99.4% and COD reduced 77.4%. The photo degradation of RhB is mainly achieved by direct photolysis of RhB by 185 nm and OH radical oxidation.Keywords microwave electrodeless UV lamp (MWUVL), photodegradation, 185 nm, rhodamine B (RhB), direct photolysis 2 Experimental 2.1 Chemicals Rhodamine B (RhB) dye of analytical grade (see structure given in Fig.

Microwave Discharge Electrodeless Lamps. Part VIII: Continuous On‐Site Solar Energy Remediation of Contaminated Water

“…Microwave discharge electrodeless lamps (MDELs) have proven useful light sources to decontaminate polluted water since both UV and microwave radiations can be applied simultaneously to induce degradative processes for destroying organics and microorganisms 2–10. For equal power consumption, MDELs are more effective than conventional low‐pressure Hg lamps 11.…”