       1 BIODEGRADABILITY OF MONOETHANOLAMINE AFTER FENTON TREATMENT SABTANTI HARIMURTI 1 *, IDZHAM F M ARIFF 2 , RAIHAN MAHIRAH RAMLI 1 , PUTRI N FAIZURA MEGAT KHAMARUDDIN 1 , BINAY K DUTTA 1 . 1 Department of Chemical Engineering, Universiti Teknologi PETRONAS, 31750 Tronoh, Perak, Malaysia 2 Novel Process & Advanced Engineering, PETRONAS Research Sdn. Bhd., 43000 Kajang, Selangor, Malaysia *Corresponding author : E8mail : sabtanti@yahoo.co.id sabtanti@yahoo.co.id ABSTRACT Alkanolamines such as monoethanolamine (MEA) in aqueous solution are commonly used for scrubbing of acid gases. High concentrations of alkanolamine waste can be generated from natural gas processing plants which may be difficult to treat in a conventional biological treatment unit. In this paper, chemical pretreatment of MEA using Fenton’s reagent prior to biological treatment was investigated. The results showed that COD removal via Fenton’s oxidation was highly dependent on initial MEA concentration with 54.5% COD removal at the highest initial MEA concentration used. Glycine was identified as a degradation by8product in the partially degraded MEA which was observed by HPLC and FTIR techniques. The aerobic biodegradability of partially degraded MEA (after 40% COD degradation by Fenton’s reagent) compared to untreated MEA was investigated using batch mixed8culture experiments to determine the kinetic coefficients for aerobic biological treatment. The results showed that biodegradability of the partially degraded MEA was improved compared to untreated MEA based on the kinetic constants and reduced acclimatization time. Dissolved ammonia was also found to be formed in significant amounts during both Fenton’s oxidation and biological oxidation. Keywords: Monoethanolamine; MEA, COD; MLSS, biodegradability. INTRODUCTION Alkanaolamines have been utilised in both household and industrial applications. In industry, they are extensively employed in natural gas processing plants where CO 2 and H 2 S are removed from natural gas by absorption with an alkanolamine solution such as monoethanolamine (MEA). During shutdown and maintenance of these facilities, high concentrations of residual MEA may be carried over into the wastewater, where they can upset conventional biological treatment systems. In this regard, advanced oxidation processes (AOP’s) have proved to be extremely effective in the degradation of high concentrations of organics which may be difficult to treat in conventional biological treatment. The more common AOP’s use either H 2 O 2 or O 3 as the source materials for the generation of strongly oxidizing radicals such as hydroxyl (HO • ) and hydroperoxyl (HO 2 • ) in solution. Ultraviolet radiation or ferrous sulfate, separately or in combination, is used to initiate the process of generation of the oxidizing radicals. Fenton’s reagent, a mixture of hydrogen peroxide and ferrous sulfate in aqueous solution, has proved to be more effective than UV8H 2 O 2 or UV8O 3 for most of the recalcitrant organics [9]. In Fenton’s oxidation, reactions (1) and (2) are generally accepted to occur: