Adsorption Potential of Schizophyllum commune White Rot Fungus for Degradation of Reactive Dye and Condition Optimization: A Thermodynamic and Kinetic Study

The pollution due to dyes from textile sector is one of the major issues faced worldwide. This study was focused on the removal of the reactive dye, Drimaren Turquoise CL-B using Schizophyllum commune, a white rot fungus (WRF) keeping in mind the current environmental conditions. Different parameters like pH, sources of carbon & nitrogen, temperature, concentration of dye and C/N ratio were used to investigate their effect on the process. Maximum dye removal of 95.45% was obtained at pH 4.5, temperature 35°C, inoculum size 3 mL, veratryl alcohol (mediator), glucose (carbon source) and ammonium nitrate (nitrogen source). The enzyme activity was determined by employing enzyme assay. Laccase and Lignin peroxidase (LiP) activity was low while Manganese peroxidase (MnP) activity was highest. Maximum bio-sorption was achieved at pH 1 and 313 K. The pseudo-2nd-order kinetic model & Freundlich isotherm was best suited for the process of removal of dye. From these data, it is concluded that white rot fungus could possibly be the excellent biomaterial for elimination of synthetic dyes from wastewater.

Methanol to Formaldehyde: An Overview of Surface Studies and Performance of an Iron Molybdate Catalyst

Formaldehyde is a primary chemical in the manufacturing of various consumer products. It is synthesized via partial oxidation of methanol using a mixed oxide iron molybdate catalyst (Fe2(MoO4)3–MoO3). This is one of the standard energy-efficient processes. The mixed oxide iron molybdate catalyst is an attractive commercial catalyst for converting methanol to formaldehyde. However, a detailed phase analysis of each oxide phase and a complete understanding of the catalyst formulation and deactivation studies is required. It is crucial to correctly formulate each oxide phase and influence the synthesis methods precisely. A better tradeoff between support and catalyst and oxygen revival on the catalyst surface is vital to enhance the catalyst’s selectivity, stability, and lifetime. This review presents recent advances on iron molybdate’s catalytic behaviour for formaldehyde production—a deep recognition of the catalyst and its critical role in the processes are highlighted. Finally, the conclusion and prospects are presented at the end.

Purification of arsenic-contaminated water using iron molybdate filters and monitoring of their genotoxic, mutagenic, and cytotoxic effects through bioassays

Environmental contamination has been a cause of concern worldwide, being aggravated by anthropogenic activities carried out without the correct disposal of toxic products in the various habitats on our planet. In Brazil, mining companies are responsible for the contamination of large river basins with toxic elements from mining activities. Among these elements, arsenic draws attention because it is highly carcinogenic and found in waters in concentrations above those recommended by regulatory agencies. Here, Fe₂(MoO₄)₃ nanoparticles are synthesized and used as a filter medium in water purification systems contaminated with arsenic. The adsorption kinetics of arsenic by Fe₂(MoO₄)₃ nanoparticles is fast, showing pseudo-second-order rate constants of 0.0044, 0.0080, and 0.0106 g mg^-1 min^-1 for As³⁺, As⁵⁺, and MMA, respectively. The adsorption isotherms are better adjusted with the Langmuir and Redlich-Peterson models, indicating that the arsenic adsorption occurs in monolayers on the Fe₂(MoO₄)₃ surface. The Fe₂(MoO₄)₃ adsorption capacities determined for the As³⁺, As⁵⁺, and MMA species are 16.1, 23.1, and 23.5 mg g^-1, respectively. The Fe₂(MoO₄)₃ filter is efficient in purifying arsenic-contaminated water, reducing its initial concentration from 1000 μg L^-1 to levels close to zero. Biological tests indicate that Fe₂(MoO₄)₃ nanoparticles and filtered water have no cytotoxic, genotoxic, and mutagenic risks to human life. Those results suggest that the Fe₂(MoO₄)₃ filter can be used as an efficient and safe technology for the purification of water contaminated by arsenic.

Kinetic and thermodynamic studies for evaluation of adsorption capacity of fungal dead biomass for direct dye

This study focuses on evaluation of degradation aptitude of white rot fungus (Coriolus versicolor) against Indosol Turquoise FBL dye. The outcome of numerous parameters including pH, temperature, carbon sources, nitrogen sources, C/N ratio and effect of dye concentration were studied. Maximum decolorization (99.896%) of Indosol Turquoise FBL was obtained by C. versicolor under optimized conditions. After three days, the maximum dye degradation (98%) was observed at pH 4 and 30 °C. Six carbon sources fructose, glucose, maltose, sucrose, rice bran and wheat bran were used and 96.66% degradation was observed by maltose at its optimum growth concentration (0.1 g/100 mL). Various nitrogen sources were employed for decolorization but ammonium nitrate decolorized dye up to 98.05%. The activity of three different enzymes laccase, Lignin peroxidase (LiP) and Manganese peroxidase (MnP) were calculated. The dead biomass of White rot fungus (WRF) was used for biosorption experiments. Maximum q (36 mg/g) was obtained at pH 2, at 30 °C using 0.05 g biosorbent. An increase in the q value was observed with increase in dye concentration. Freundlich adsorption isotherm and pseudo second order kinetics were followed by the data. It can be concluded that C. versicolor could be an efficient source for degradation of dyes from industrial effluents.

Experimental modeling, optimization and comparison of coagulants for removal of metallic pollutants from wastewater

Wastewater treatment coagulation is one of the most important physicochemical operations used in industry. The adsorption capability of marigold leaf powder, tea waste and ferrous sulfate was investigated for domestic and tannery effluents. These adsorbents significantly affected the pH, electrical conductivity (EC) and turbidity of wastewater. Maximum decrease in all the attributes was observed for 10 g of adsorbents application. All the adsorbents significantly affected the physiochemical attributes of both wastewaters. Similarly, maximum adsorption potential was observed in case of tea waste powder. Maximum decrease in all physiochemical attributes such as pH (15%), EC (21%), turbidity (54%), total dissolved solids (TDS; 36%), total suspended solids (TSS; 43%), total hardness (TH; 52%), chloride contents (59%) and phosphate contents (60%) was observed with the application of 10 g of tea waste. Regarding the heavy metals, maximum decrease for cadmium (Cd; 47%), lead (Pb; 81%), arsenic (As; 44%), copper (Cu; 75%), iron (Fe; 49%), chromium (Cr; 68%) and zinc (Zn; 64%) was observed in same treatment. The decreasing order in terms of their adsorption potential for coagulants was tea waste > marigold leaf powder > ferrous sulfate. However, for the wastewater, the maximum effect of adsorbents was observed in case of domestic wastewater as compared to the tannery water. Based on these data, it is suggested that tea waste has maximum adsorption potential for the remediation of wastewater.