Soon-An Ong

Combination of adsorption and biodegradation processes for textile effluent treatment using a granular activated carbon-bioflm confgured packed column system

The objective of this study was to investigate the feasibility of using a granular activated carbon-biofilm configured packed column system in the decolorization of azo dye Acid Orange 7-containing wastewater. The Acid Orange 7-degrading microbial from anaerobic sequencing batch reactor which treating the azo dye-containing wastewater for more than 200 d was immobilized on spent granular activated carbon (GAC) through attachment. The GAC-biofilm configured packed column system showed the ability to decolorize 100% of the azo dye when working at high loading rate of Acid Orange 7 at 2.1 g/(L x d) with treatment time of 24 h. It was observed that the decolorization rate increased along with the increasing of initial Acid Orange 7 concentrations, until it reached an optimum point at about 0.38 g/h with initial Acid Orange 7 concentrations of 1,150 mg/L and the decolorization rate tend to be declined beyond this concentration.

Decolorization of Orange II using an anaerobic sequencing batch reactor with and without co-substrates

We investigated the decolorization of Orange II with and without the addition of co-substrates and nutrients under an anaerobic sequencing batch reactor (ASBR). The increase in COD concentrations from 900 to 1750 to 3730 mg/L in the system treating 100 mg/L of Orange II-containing wastewater enhanced color removal from 27% to 81% to 89%, respectively. In the absence of co-substrates and nutrients, more than 95% of decolorization was achieved by the acclimatized anaerobic microbes in the bioreactor treating 600 mg/L of Orange II. The decrease in mixed liquor suspended solids concentration by endogenous lysis of biomass preserved a high reducing environment in the ASBR, which was important for the reduction of the Orange II azo bond that caused decolorization. The maximum decolorization rate in the ASBR was approximately 0.17 g/hr in the absence of co-substrates and nutrients.

ARTIFICIAL AERATION TO ENHANCE THE MINERALIZATION OF MONO AZO (METHYL ORANGE)-CONTAINING WASTEWATER USING RECIRCULATED UP-FLOW CONSTRUCTED WETLAND

The aim of this study is to evaluate the treatment performance of mono azo dye Methyl Orange (MO)-containing wastewater by recirculated up-flow constructed wetland (UFCW) with and without supplementary aeration. The successive anaerobic and aerobic treatment of the UFCW reactors could effectively remove color, organic matters and intermediate aromatic amines simultaneously in a single reactor. With influent 50 mg/L of MO, the removal efficiencies of COD and MO were 91 and 75 %, respectively, in the aerated wetland reactor, whereas the removal efficiencies were 86 and 93 %, respectively, in the non-aerated wetland reactor. The aerated wetland reactor outperformed the non-aerated wetland reactor in the removal of organic matters and aromatic amines. The accumulation of aromatic amines in the non-aerated wetland reactor was observed as shown in the increase of ratio absorbance at 270 nm/465 nm and UV-Vis spectra analysis.