Potentiality of the Phoma sp. inactive fungal biomass, a waste from the bioherbicide production, for the treatment of colored effluents

Combined microbe-plant remediation of cadmium in saline-alkali soil assisted by fungal mycelium-derived biochar

Cadmium contamination in saline-alkali soil is becoming a great concern. Combined microbe-plant remediation is an economic way to treat this contamination, but is compromised by its low cadmium-removing capacity. In this study, the novel fungus-derived biochar was prepared to enhance the salt-tolerant bacterium-plant remediation of cadmium-contaminated saline-alkali soil. This biochar was prepared by pre-incubation of living Trichoderma atroviride hyphae with imidazole and further heating at 500 °C for 1 h. The obtained fungus-derived nitrogen-doped biochar (FBioCN) exhibited the high affinity to bacterial cells, leading to efficient colonization of exogenous salt-tolerant bacteria (e.g., Rhizobacter sp. and Sphingomonas sp.) on Amaranthus hypochondriacus roots. During culturing of the plants in the cadmium-contaminated saline-alkali soil, FBioCN drastically remodeled the rhizosphere microbiome, leading to enhance colonization of the exogeneous salt-tolerant bacteria, and increase bacterial diversity. The combination of FBioCN and the exogeneous bacteria further improved the activity of rhizosphere functional enzymes, protected the plants from the multiple stress, and promoted cadmium transport from the soil to the plants. Consequently, FBioCN together with the salt-tolerant bacteria drastically improved cadmium removal from the saline-alkali soil, with the percent of cadmium removal at the rhizosphere region increasing from 35.1% to 95.1%. This study sheds a light on the application of fungus-derived biochar in combined microbe-plant remediation in saline-alkali soil.

Biosorption of Cr (VI) by acid-modified based-waste fungal biomass from Calocybe indica fruiting bodies production

The world is going through a colossal drinking water scarcity. Unchecked discharge (even at trace levels) of Cr (VI) from industries into water bodies is a serious environmental concern. Here, we report waste fungal biomass (WFB) for the detoxification and removal of chromium ions. Biomass understudy was collected from Calocybe indica fruiting bodies. WFB was used after drying and pretreatment with two distinctive chemical methods, which improved the remediation effectiveness of Cr (VI). Light microscope and Field emission Scanning microscope (FESEM) were employed to elucidate the surface morphology of waste fungal biomass. While Fourier-Transform Infrared-Spectroscopy (FTIR) and Energy Dispersive X-Ray analysis (EDAX) were deployed to explore the mechanism of interaction between Cr (VI) anion and waste fungal biomass. X-ray Photoelectron Spectroscopy (XPS) analyses demonstrated considerable conversion of Cr (VI) into nontoxic Cr (III) species. The most favorable condition for optimum Cr (VI) remediation of 99.66% by treated waste fungal biomass (TWFB) occurred at pH 3, contact time 10 min, adsorbent dosage 3 gL^-1, Cr (VI) concentration 4 mgL^-1, stirring speed 140 rpm, and temperature 320 K, where for untreated waste fungal biomass (UWFB) the optimum of 85% remediation occurred at a contact time 15 min, and adsorbent dosage 2 gL^-1 whereas other experimental conditions remained identical as TWFB biosorbent. Pseudo-second-order kinetics (R² > 0.99) model matched the adsorption rate. And, the Freundlich isotherm model (R² > 0.99) is shown to be a better match for the experimental data. The optimum amount of Cr (VI) adsorbed by the TWFB and UWFB were 205.8 ± 10.1 and 72.85 ± 2.36 mgg^-1, respectively. Thermodynamic parameters revealed that the adsorption was spontaneous (ΔG ˂ 0), endothermic (ΔH > 0), and entropy-driven (ΔS > 0). The generated WFB adsorbent also has significant recycling potential. After five cycles of regeneration and adsorption. It can still keep up good remediation effectiveness of Cr (VI) ions to 85.5.

Recent advances in biodecolorization and biodegradation of environmental threatening textile finishing dyes

Organic nature of dyes and their commercially made products are widely utilized in many industries including paper, cosmetics, pharmaceuticals, photography, petroleum as well as in textile manufacturing. The textile industry being the top most consumer of a large variety of dyes during various unit processes operation generates substantial amount of wastewater; hence, nominated as "Major Polluter of Potable Water". The direct discharge of such effluents into environment poses serious threats to the functioning of biotic communities of natural ecosystems. The detection of these synthetic dyes is considered as relatively easy, however, it is extremely difficult to completely eliminate them from wastewater and freshwater ecosystems. Aromatic chemical structure seems to be the main reason behind low biodegradability of these dyes. Currently, various physiochemical and biological methods are employed for their remediation. Among them, microbial degradation has attracted greater attention due to its sustainability, high efficiency, cost effectiveness, and eco-friendly nature. The current review presents recent advances in biodegradation of industrial dyes towards a sustainable and tangible technological innovative solutions as an alternative to existing conventional physicochemical treatment processes.

Application of biorefinery by-product of Nigella sativa L. herb for green treatment of synthetic dye impurity in aquatic environment: a circular economy based approach to water purification

In this work, the performance of residual biomass of Nigella sativa L. plant from the process of bio-oil production toward the green removal of synthetic dye pollution from aquatic medium was systematically studied for the first time based on the circular economy strategy. The characterization of material was performed using Electron Microscope of Scanning and Infrared Spectrometer of Fourier Transform. The main process variables like pH, biosorbent amount, synthetic dye loading, and contact duration were optimized by the batch biosorption experiments to achieve the maximum remediation yield. The analyses of kinetics, equilibrium, and thermodynamics were conducted to understand the possible mechanism of purification. The experimental dynamics and equilibrium data were in better agreement with the pseudo-second-order and Langmuir models. For the targeted model synthetic dye compound (C. I. Basic Red 46), the biosorption capacity was obtained as 136.2 mg g^-1 at the optimized conditions of pH of 8, biosorbent amount of 10 mg (100 mg L^-1), synthetic dye loading of 30 mg L^-1, and duration of 360 min. The treatment process was favorable, spontaneous, and physical. The characterization operation showed that the dye molecules were restrained on the rough surface of biosorbent. This study reveals that the reuse of herbal oil refinery residue as a biosorbent can present an economic, efficient, and eco-friendly option for the remediation of synthetic dye pollution in aqueous medium.

A novel biowaste-based biosorbent material for effective purification of methylene blue from water environment

The biowaste left over from the fixed oil biorefinery process of Nigella sativa L. plant was used as a new biosorbent for the biosorption of synthetic dye of methylene blue from water environment in this study. The main variables of biosorption operation such as methylene blue concentration, time, pH, and biosorbent amount were optimized by the batch-type experiments. The characterization, kinetics, equilibrium, and thermodynamics works were conducted to show the nature of methylene blue biosorption. The studies of Fourier transform infrared spectroscopy and Scanning electron microscopy indicated that the biosorbent possessed an inhomogeneous surface morphology including many cavities and protuberances, and a rich functional group profile. The optimum values of operating variables studied for the biosorption of methylene blue were determined as methylene blue concentration of 15 mg L^-1, time of 360 min, pH of 8, and biosorbent amount of 10 mg. The experimental data of methylene blue biosorption followed the kinetics and isotherm models of pseudo-second-order (R²: 0.98, AdjR²: 0.98, and RMSE: 8.97) and Dubinin-Radushkevich (R²: 0.99, AdjR²: 0.98, and RMSE: 6.84), respectively, based on the statistical tests of coefficient of determination (R²), adjusted coefficient of determination (AdjR²), and root mean squared error (RMSE). The biosorption of methylene blue was a physical, spontaneous, and energetically favorable process (E_DR: 3.48 kJ mol^-1 and ΔG°: (-14.51) - (-10.02) kJ mol^-1). This residual biological material from the fixed oil biorefinery process exhibited higher biosorption performance (187.46 mg g^-1) than own unrefined (virgin) form and its modified, activated, and composite forms and many other sorbents reported in the literature. Hereby, the current work showed that this novel biowaste-based material could be used as an environmentally and economically promising biosorbent to effectively purify methylene blue from aquatic environment.

Biosorption of cationic and anionic dyes using the biomass of Aspergillus parasiticus CBS 100926T

Aspergillus parasiticus (A. parasiticus) CBS 100926^T was used as a biosorbent for the removal of Methylene Blue (MB), Congo Red (CR), Sudan Black (SB), Malachite Green Oxalate (MGO), Basic Fuchsin (BF) and Phenol Red (PR) from aqueous solutions. The batch biosorption studies were carried out as a function of dye concentration and contact time. The biosorption process followed the pseudo-first-order and the pseudo-second-order kinetic models and the Freundlich and Langmuir isotherm models. The resulting biosorbent was characterized by Scanning Electron Microscopy (SEM), X-Ray Diffractometer and Fourier Transformer Infrared Spectroscopy (FTIR) techniques. The results of the present investigation suggest that A. parasiticus can be used as an environmentally benign and low cost biomaterial for the removal of basic and acid dyes from aqueous solution.

Study on adsorption of ammonia nitrogen by iron-loaded activated carbon from low temperature wastewater

In order to improve the adsorption efficiency of ammonia nitrogen in low temperature wastewater, the modified activated carbon (Fe-AC) was prepared by impregnation-calcination modification of Fe(NO₃)₃. The characterization results indicated that the total pore volume, specific surface area and the point of zero charge of activated carbon increased after modification. A better adsorption effect was achieved under neutral condition than under alkaline or acidic condition. The effect of Ca²⁺ on competitive adsorption of NH₄⁺ was greater than that of Na⁺ when both cations were present. Pseudo-first-order kinetic model was confirmed to be consistent with Fe-AC adsorption kinetic data, and Langmuir model was consistent with adsorption isotherm data. The adsorption thermodynamics demonstrated that the ammonia nitrogen adsorption process by Fe-AC was spontaneous and low-temperature was helpful to improve the adsorption capacity. The mechanism of adsorption of ammonia nitrogen by Fe-AC was the comprehensive effect of physical adsorption and chemical adsorption, which was the essential reason for improving the adsorption efficiency of ammonia nitrogen by Fe-AC at a low temperature. This research offered a new way for the modification of activated carbon and a new method for the removal of ammonia nitrogen at a low temperature.

Conversion of MDF wastes into a char with remarkable potential to remove Food Red 17 dye from aqueous effluents

Medium density fiberboard (MDF) wastes were converted into an efficient char able to uptake Food Red 17 dye (FR17) from colored effluents. The yield of the pyrolysis process, in terms of char, was 29%. The produced char presented micro and mesoporous, with surface area of 218.8 m² g^-1 and total pore volume of 0.122 cm³ g^-1. Regarding to the FR17 adsorption, removal percentages of 90% were found at pH 2 and using 0.5 g L^-1 of char. Pseudo-first and pseudo-second order models were adequate to represent the adsorption kinetic profile, being the equilibrium reached within 20 min. Freundlich model was selected to represent the equilibrium data. The maximum adsorption capacity was 210 mg g^-1. The adsorption of FR17 on the char was endothermic and physical in nature. The char was efficient for 8 adsorption-desorption cycles, maintaining the same adsorption capacity. In brief, this work demonstrated a useful practice in terms of cleaner production. It was possible add value to MDF wastes, generating an efficient and reusable adsorbent to treat colored effluents containing FR 17 dye.

Comments on "Breakthrough analysis of continuous fixed-bed adsorption of sevoflurane using activated carbons"

This communication discusses the fixed bed modeling results of the recent paper published by Ang et al. (2020) in this journal.