This study revealed Streptomyces bacillaris as an efficient biological agent for the removal of triphenylmethane (TPM) dyes. The isolate decolorized Malachite Green (MG), Methyl Violet (MV), Crystal Violet (CV), and Cotton Blue (CB) effectively. S. bacillaris in the treated dye solutions were analyzed for enzyme production, and the cell biomass was observed for functional groups and cell morphology. The treated dye solutions were also analyzed for degraded compounds and their toxicity. Results revealed high decolorization activities for MG (94.7%), MV (91.8%), CV (86.6%), CB (68.4%), attributed to both biosorption and biodegradation. In biosorption, dye molecules interacted with the hydroxyl, amino, phosphoryl, and sulfonyl groups present on the cell surface. Biodegradation was associated with induced activities of MnP and NADH-DCIP reductase, giving rise to various simpler compounds. The degraded compounds in the treated dyes were less toxic, as revealed by the significant growth of Vigna radiata in the phytotoxicity test. There were no significant changes in cell morphology before and after use in dye solutions, suggesting S. bacillaris is less susceptible to dye toxicity. This study concluded that S. bacillaris demonstrated effective removal of TPM dyes via biosorption and biodegradation, rendering the treated dyes less toxic than untreated dyes. Findings in this study enabled further explorations into the potential application of lesser-known actinobacteria (i.e. Streptomyces sp.) for dye removal.
The toxic wastewater effluents from textile dyes have been a significant environmental threat worldwide in recent decades. Against this backdrop, this study investigates the performance of C@Fe3O4-MoO3-rGO as a sonoadsorbent to ameliorate crystal violet (CV) dye from the aqua matrix and further explores its potential as an electrode in supercapacitor applications. The phase purity, crystal structure, surface morphology, thermal stability and magnetic behaviour characteristics of the composite were studied using various characterisation techniques such as powder X-ray diffraction (XRD), Raman Spectroscopy, Fourier transform infrared spectroscopy (FTIR), Field emission scanning electron microscopy (FESEM), High-resolution transmission electron microscopy (HRTEM), Thermogravimetric analysis (TGA) and Vibrating-sample magnetometry (VSM). From the Langmuir isotherm model, the synthesised sonoadsorbent exhibited a maximum adsorption capacity of 1664.26 mg/g for crystal violet, which is remarkably high. Further, to its inherited magnetic characteristics, the composite can be easily separated from the solution by using an external magnet. Furthermore, the working electrode was synthesised with 80% active material, 10% carbon black, and 10% polyvinylidene difluoride to investigate its suitability in supercapacitor applications. The C@Fe3O4-MoO3-rGO composite exhibited an excellent capacitance value of 180.36 F/g with commendable cycling stability, making it suitable as a potential cathode material for the next generation supercapacitors.
Triphenylmethane dyes (TPM) are recalcitrant colorants brought into the environment. In this study, a lesser-known white rot fungus Coriolopsis sp. (1c3), isolated from compost of Empty Fruit Bunch (EFB) of oil palm, was explored for its decolorization potential of TPM dyes. The isolate 1c3 demonstrated good decolorization efficiencies in the treatment of Crystal Violet (CV; 100 mg l(-1)), Methyl Violet (MV; 100 mg l(-1)) and Cotton Blue (CB; 50 mg(-1)), with 94%, 97% and 91%, within 7, 7 and 1 day(s), respectively. Malachite Green (MG; 100 mg l(-1)) was the most recalcitrant dye, with 52% decolorization after 9 days. Dye removal by 1c3 was presumably via biosorption, whereby the process was determined to be influenced by fungal biomass, initial dye concentrations and oxygen requirements. Biodegradation was also a likely mechanism responsible for dye removal by 1c3, occurred as indicated by the reduction of dye spectra peaks. Detection of laccase, lignin peroxidase and NADH-DCIP reductase activities further substantiate the possible occurrence of biodegradation of TPM dyes by 1c3.
The isolate Coriolopsis sp. (1c3) was cultured on muslin cloth to induce formation of filamentous biofilm. The biofilm and the free-mycelium forms (control) were then used to treat two triphenylmethane dyes; Cotton Blue (CB) and Crystal Violet (CV). The biofilm comprised primarily of a compact mass of mycelium while sparse mycelium network was detected in free-mycelium forms. Results revealed significant decolourization activities by filamentous biofilm of 1c3 for CB (79.6%) and CV (85.1%), compared to free-mycelium forms (72.6 and 58.3%, for CB and CV, respectively). Biodegradation occurred in both biofilm and free-mycelium forms. FTIR spectra revealed that biofilm formation (stacking of mycelium), did not have severe implications to the number and types of functional groups available for dye biosorption. The findings here suggested that formation of biofilm in 1c3 was induced effectively on muslin cloth, leading to enhanced decolourization activities. This technology is simple, feasible and can be adopted and further improved to obtain biofilm to enhance their dye removal efficiency in aqueous solutions.
In this paper, we present the synthesis of C@Fe3O4-MoO3 binary composite were prepared through the facile hydrothermal process. The ultrasonic aided adsorption efficacy was evaluated by studying triphenylmethane dye's adsorption potential. The ultrasonic aided adsorption capacity towards crystal violet was 993.6 mg/g, which is remarkably higher and best fitted with the Langmuir isotherm model and followed pseudo-second-order kinetics. The electrochemical studies working electrode have been prepared with 80 wt% active material, 10 wt% carbon black, and 10% polyvinylidene difluoride to evaluate energy storage characteristics. The C@Fe3O4-MoO3 demonstrated an excellent specific capacitance of 40.94 F/g with better retention and stability, making it a potential cathode material for next-generation electrochemical energy storage devices.
Deep eutectic solvents (DESs) are novel solvent media that are currently under investigation as an alternative to ionic liquids and conventional solvents. The physical properties of DESs as well as their mild environmental footprint and potentially critical industrial application necessitate understanding the interaction of functional groups on both the salt and hydrogen bond donor (HBD). In this study, four DESs were prepared by mixing triethylenglycol, diethylenglycol, ethylenglycol, and glycerol as HBDs with methyltriphenylphosphonium bromide as a salt at a molar ratio of 1:4. Fourier transform infrared spectroscopy was conducted to highlight the chemical structure and mechanism of the combination of the four DESs. New spectra illustrating the combination of the functional groups of the HBDs and salt were observed and interpreted. This study is the first to investigate the properties of neoteric phosphonium-based DESs.