DEGRADATION OF DIISOPROPANOLAMINE USING FENTON‟S REAGENT

Diisopropanolamine (DIPA) has been widely used as an additive in cosmetic and personal care products, as corrosion inhibitor and lubricating agent in metalworking fluids, as drug intermediates in pharmaceutical industry and as solvent to remove acid gas from raw natural gas. Thus, wastewater contaminated of DIPA is constantly generated. However, despite the facts, a treatment method to treat the DIPA contaminated wastewater has yet to be developed. Most industrial wastewater treatment plant use conventional biological treatment system to treat wastewater because the system can handle large volume of wastewater at a time. Unfortunately, this system could not treat recalcitrant pollutant such as organic compounds. The DIPA contaminated wastewater is characterized as having high chemical oxygen demand (COD) which makes it impossible to be treated by the conventional wastewater treatment system. Shock loading of COD into the system may cause process upset. Due to this fact, a new way to treat these recalcitrant components has to be identified. The pretreatment of the waste is necessary prior entering the wastewater treatment plant to meet the local standard requirement. In latter decades, advanced oxidation processes (AOP) has been identified to be able to degrade wide range of recalcitrant organic compounds. The simplest AOP that has been applied is Fenton oxidation process. The applicability of this process to degrade organic compounds to biodegradable or harmless products has been widely reported. In this research, viability of Fenton‟s reagent to degrade DIPA to biodegradable products was studied. The degradability of DIPA was measured by the reduction of COD in the treated wastewater sample. The percentage COD reduction was found to be higher with higher initial concentration of amine. Highest COD reduction (74 %) in Fenton oxidation of synthetic wastewater was achieved at initial pH of 2 with H2O2/Fe2+ molar ratio of 10, while for real wastewater sample degradation (72 % COD removal) is most favored at pH of 3 with H2O2/Fe2+ molar ratio of 12. Continuous addition of Fenton‟s reagents is much more effective with better utilization of hydrogen peroxide compared to single addition. In the research, significant COD reduction was observed at the optimum condition and parameters. Carboxylic acids (formic, oxalic and acetic) and glycine were identified as
the degradation products. The residual COD could be further decrease in biological treatment system due to the presence of carboxylic acid which is more biodegradable intermediates.