Now showing 1 - 3 of 3
  • Publication
    Comparative study on the biodegradation of mixed remazol dyes wastewater between integrated anaerobic/aerobic and aerobic sequencing batch reactors
    ( 2017-09-01) ; ; ;
    Khairil Anuar Mohammad Pakri
    Complete mineralization of dye effluent was realized through sequential anaerobic followed by aerobic processes. The aim of this study was to evaluate and compare the degradation of wastewater of four remazol dyes with integrated anaerobic/aerobic (SBR1) and aerobic (SBR2) processes under sequencing batch reactor operation. The ORP profiles show that the SBR1 was in anaerobic condition during the 15 h React mode and turned to aerobic condition through air aeration for 3 h. The SBR1 and SBR2 achieved almost similar performance in the removal of organic compounds with average 95% COD removal. The SBR1 performed better in the color removal with 93% removal efficiency while the SBR2 only attained 50% removal efficiency. The biodegradation rate of the remazol dyes was well described by the first-order kinetic model with the sequence degradation rate remazol pink > remazol violet > remazil yellow > remazol green.
      27  1
  • Publication
    Intermolecular mechanistic treatment of recalcitrant environmental pollutants: Azo, benzene, naphthalene and vinyl sulfone
    A new class of coagulant, from natural resource namely laterite soil has demonstrated efficiency in degrading a wide range of industrial organic pollutants into simple hydrocarbon structures or less toxic compounds. The composition study revealed the relative Si/Al/Fe: 0.57/0.33/0.10 ratios in laterite soil and surface morphology of laterite soil were investigated to analyze the fundamental degradation that drive the decolorization of Reactive Black 5 (RB 5). The interfacial and colloid aspects of laterite soil colloidosomes and dye particles were distinguished with the corresponding mechanism of coagulation–flocculation process. RB5 structure was destabilized by activation of laterite soil colloidosomes through charge neutralization and subsequent siloxane polymerization through enhancement of siloxanes monomers. This research also evaluated the rate laws and reaction mechanism for each of the main chemical network strands of RB 5. The result implied that all the chemical network strands followed the pseudo first order of reactions. Research approach has utilized Fourier Transform Infrared Spectroscopy, Gas Chromatography Mass Spectrometry and Ultraviolet–visible Spectrophotometry (FTIR, GCMS and UV–vis) to study the degradation intermediates structure, chemical derivatives and final products after coagulation–flocculation process.
      2  26
  • Publication
    Chemical and biological combined treatment for sugarcane vinasse: selection of parameters and performance studies
    Sugarcane vinasse has been reported as a high strength industrial wastewater that could cause severe environmental pollution due to its complex and bio-refractory compounds. Thus, the combined coagulation and sequencing batch biofilm reactor (SBBR) system was employed for the sugarcane vinasse treatment. This study aims to determine the recommended conditions of various parameters under coagulation and SBBR and investigate the effectiveness of combined processes. First, the approach of the coagulation process could achieve the maximum COD reduction and decolorization efficiencies of 79.0 ± 3.4% and 94.1 ± 1.9%, respectively, under the recommended conditions. Next, SBBR as an integrated biofilm reactor showed excellent synergistic biodegradability, removing 86.6 ± 4.3% COD concentration and 94.6 ± 3.8% color concentration at 3.0 g·COD/L of substrate loading concentration. The kinetic studies of SBBR revealed that the first-order kinetic model was the best fit for COD reduction efficiency. In contrast, the second-order kinetic model was the best fit for decolorization efficiency. The SBBR reaction was further investigated by ultraviolet–visible spectrophotometry (UV–Vis). In the combined processes, SBBR followed by the coagulation process (SBBR–CP) showed greater COD reduction and decolorization efficiencies (97.5 ± 0.3 and 99.4 ± 0.1%) when compared to the coagulation process followed by SBBR (CP–SBBR). This study demonstrated the removal performance and potential application of the combined sequential process to produce effluent that can be reused for bioethanol production and fertigation. This finding provides additional insight for developing effective vinasse treatment using combined chemical and biological processes.
      4  46