Removal of Reactive Black 5 Dye by Banana Peel Biochar and Evaluation of Its Phytotoxicity on Tomato

Mandarin biochar-CO-TETA was utilized for Acid Red 73 dye adsorption from water, and its isotherm and kinetic studies were investigated

Environmental pollution is a major issue today due to the release of dyestuff waste into the environment through industrial wastewater. There is a need for affordable and effective adsorbents to remove harmful dyes from industrial waste. In this study, Mandarin biochar-CO-TETA (MBCOT) adsorbent was prepared and used to remove Acid Red 73 (AR73) dye from aqueous solutions. The efficiency of dye removal was influenced by various factors such as solution pH, contact time, initial AR73 dye concentration, and MBCOT dosage. All experiments were conducted at 25 ± 2 °C, and the optimal pH was determined to be 1.5. The optimal conditions for dye removal were found to be an AR73 dye concentration of 100 mg/L, an MBCOT dosage of 1.5 g/L, and a contact time of 150 min, resulting in a 98.08% removal rate. Various models such as pseudo-first-order (PFO), pseudo-second-order (PSO), film diffusion (FD), and intraparticle diffusion (IPD) were used to determine the adsorption kinetics of AR73 dye onto MBCOT. The results showed that the PSO model best explains the AR73 dye adsorption. Furthermore, Langmuir and Freundlich's isotherm models were studied to explain the adsorption mechanism using experimental data. The adsorption capacities at equilibrium (qe) in eliminating AR73 dye varied from 92.05 to 32.15, 128.9 to 65.39, 129.25 to 91.69, 123.73 to 111.77, and 130.54 to 125.01 mg/g. The maximum adsorption capacity (Qm) was found to be 140.85 mg/g. In conclusion, this study demonstrates that biochar produced from mandarin peels has the potential to be an effective and promising adsorbent for removing AR73 dye from water.

Microorganism-mediated bioremediation of dyes from contaminated soil: Mechanisms, recent advances, and future perspectives

Many methods have been proposed for the remediation of dye-contaminated soils, a widespread form of environment pollution. Bioremediation, it is hoped, can combine ecological benefits with efficiency of dye decontamination. We review the types and sources of dye contaminants; their possible effects on plant, animal, and human health; and emerging strategies for microbial bioremediation. Challenges, limitations, recommendations for future research, and prospects for large-scale commercialization of microbial bioremediation are discussed.

Selective adsorption of single and binary dyestuffs by citrus peel: Characterization, and adsorption performance

The powdered citrus peel, which has been replaced with sodium hydroxide, was used in this study to test how well methylene blue and reactive black 5 dyestuff absorbed one or both. To find out about the texture and surface chemistry of modified citrus peel, Fourier transform infrared spectroscopy and scanning electron microscope analyses were carried out. Fourier transform infrared spectroscopy data revealed the presence of amphoteric radicals on the modified citrus peel surface, indicating the effective adsorption of methylene blue and reactive black 5. Many parameters affecting the batch adsorption process, such as modified citrus peel dose (0.1-0.5 g), pH (2-10), time (20-80 min), stirring speed (60-180 rpm), and temperature (20-45 °C), were studied. It is seen that the physical effect is at the forefront, homogeneous monolayer adsorption occurs, and the process fits the Langmuir and pseudo first order models for dyestuffs. Thermodynamic modeling showed that the adsorption of methylene blue and reactive black 5 was spontaneous and endothermic. At pH 2, an adsorption capacity of 0.67 mg/g and a removal efficiency of 66.86% were achieved for reactive black 5. For methylene blue at pH 6, the adsorption capacity was 4.34 mg/g, and the decolorization rate was 87%. The decreases in the removal rates of dyestuffs in the binary system indicate that they are affected by their simultaneous presence in the solution. The results proved that modified citrus peel can be useful for dyestuff removal in single or binary systems, although the removal capacity of modified citrus peel is highly dependent on methylene blue and reactive black 5.

Sustainable use of low-cost adsorbents prepared from waste fruit peels for the removal of selected reactive and basic dyes found in wastewaters

Agricultural wastes are potential sustainable adsorbents since they are available in large quantities, are low-cost, and may require little or no treatment, in some cases. In this study, several fruit peels, such as banana, orange, and pomegranate, were collected from local markets and prepared by a simple and eco-friendly method and used as natural adsorbents for the removal of both anionic (Reactive Red 120 (RR120), Reactive Black 5 (RB5), Remazol Brilliant Blue R (RBBR)) and cationic Methylene Blue (MB) dyes found in wastewaters. Many industries, such as leather and textiles, can release huge amounts of synthetic dyes into the wastewater during dyeing processes. These are one of the most important pollutants of water pollution as they cause enormous damage to the water body and also affect the health of organisms due to their toxicity and carcinogenicity. The search for a sustainable and at the same time efficient material for the removal of a wide variety of dyes is the innovation of this work. These peels were prepared by washing, drying, grinding, and finally sieving, under natural sustainable conditions. Porosometry (BET analysis), FTIR, SEM/EDS, and XRD techniques were used to characterize the fruit peels before and after the adsorption process. Factors affecting the adsorption of dyes (adsorbent dosage, pH solution, initial concentration of dyes, contact time, and temperature) were investigated. According to the results, in terms of the effectiveness of fruit peels as (natural) adsorbent materials, for anionic dyes, 5.0-6.0 g/L of banana or orange dry peels was sufficient to remove near or even more than 90% anionic dyes at pH 2.0, and 4.0 g/L was sufficient to remove 98% of cationic MB dye at pH 9.0. Similar amount of pomegranate peels had lower efficiency for anionic dyes (50-70%), while cationic MB was still efficiently removed (98%) at pH 9.0. Moreover, the adsorption process in all cases was found to better fit to pseudo-second-order model, in comparison to pseudo-first-order model. According to isotherms, Freundlich model fitted better in some cases to the equilibrium data, while the Langmuir model in others. Finally, this study demonstrates the viability of reusing the banana, orange, and pomegranate peel adsorbents for eight, four, and five cycles, showing a gradual reduction of around 50% of their effectiveness.

Agrowaste-generated biochar for the sustainable remediation of refractory pollutants

The rapid growth of various industries has led to a significant, alarming increase in recalcitrant pollutants in the environment. Hazardous dyes, heavy metals, pesticides, pharmaceutical products, and other associated polycyclic aromatic hydrocarbons (such as acenaphthene, fluorene, fluoranthene, phenanthrene, and pyrene) have posed a significant threat to the surroundings due to their refractory nature. Although activated carbon has been reported to be an adsorbent for removing contaminants from wastewater, it has its limitations. Hence, this review provides an elaborate account of converting agricultural waste into biochar with nanotextured surfaces that can serve as low-cost adsorbents with promising pollutant-removing properties. A detailed mechanism rationalized that this strategy involves the conversion of agrowaste to promising adsorbents that can be reduced, reused, and recycled. The potential of biowaste-derived biochar can be exploited for developing biofuel for renewable energy and also for improving soil fertility. This strategy can provide a solution to control greenhouse gas emissions by preventing the open burning of agricultural residues in fields. Furthermore, this serves a dual purpose for environmental remediation as well as effective management of agricultural waste rich in both organic and inorganic components that are generated during various agricultural operations. In this manner, this review provides recent advances in the use of agrowaste-generated biochar for cleaning the environment.

Utilization of electron beam irradiated carboxymethyl cellulose/polyvinyl alcohol/banana peels composite film for remediation of dyes from wastewater

In this work, polymeric composite films were fabricated utilizing stable, non-toxic, soluble, low-cost, good mechanical, and biocompatible polymers such as CMC and PVA with the waste of one of the most current fruits consumed worldwide banana peel waste (BP) as a filler. Sequences of carboxymethyl cellulose/polyvinyl alcohol/banana peel (CMC/PVA/BP) composite films with various amounts of BP utilizing eco-friendly technique (electron beam) (EB) irradiation were prepared to eliminate common hazardous organic pollutants such as methylene blue (MB) dye from its solutions. Physical characteristics like; swelling and gel % were examined. The chemical structure, thermal stability, and surface morphology were examined utilizing FT-IR, TGA, DSC, XRD, EDX, and SEM. Additionally, the UV/Vis spectroscopy study was investigated to study the impact of the various parameters such as irradiation, contact time, pH, temperature, adsorbent dosage, and initial concentration on removal efficiency % of MB dye onto the prepared composite films. The adsorption process fitted with the Langmuir model, pseudo-second-order kinetic model, endothermic, favorable, and spontaneous. The adsorption capacity of MB dye onto the CMC/PVA/BP composite film was 19.6 mg/g at the optimum conditions: irradiation dose = 20 kGy, contact time = 120 min, pH = 10, temperature = 25 °C, adsorbent dosage = 0.1 g and initial conc. = 10 mg/L.

Carbon nanoparticles improve the effect of compost and arbuscular mycorrhizal fungi in drought-stressed corn cultivation

Drought is an important threat worldwide, therefore, it is vital to create workable solutions to mitigate the negative effects of drought stress. To this end, we investigated the interactive effect of compost (Comp), arbuscular mycorrhizal fungi (AMF) and carbon nanoparticles (CNPs) on maize plant crops under drought stress. The combined treatments were more effective at increasing soil fertility and promoting the growth of maize plants under both control and drought stress conditions by 20.1% and 39.4%, respectively. The interactions between treatments, especially the effects of Comp-AMF-CNPs mixture, reduce the activity of photorespiration induced H₂O₂ production that consequently reduces drought-related oxidative damages (lipid peroxidation and protein oxidation). Plants treated with Comp-AMF or Comp-AMF-CNPs showed an increase in their antioxidant defense system. Comp-AMF-CNPs increased enzyme activities by 50.3%, 30.1%, and 71% for ascorbate peroxidase (APX), dehydro-ASC reductase (DHAR), and monodehydro-ASC reductase (MDHAR), respectively. Comp-AMF-CNPs also induced the highest increase in anthocyanins (69.5%) compared to the control treatment. This increase was explained by increased anthocyanin percussor, by 37% and 13% under control and drought, respectively. While the increases in biosynthetic key enzymes, phenylalanine aminolayse (PAL) and chalcone synthase (CHS) were 77% and 5% under control and 69% and 89% under drought, respectively. This work advanced our understanding on how Comp-AMF-CNPs improve growth, physiology, and biochemistry of maize plants under drought stress conditions. Overall, this study suggests the effectiveness of Comp-AMF-CNPs as a promising approach to enhance the growth of maize plants in dry areas.

Removal of reactive violet 5 azodye (V5R) using bamboo, and calabash biochar

We assess the adsorption capacity of bamboo and calabash biochar (BB and CB). Using 10-50 mg/L Reactive Violet 5 Azo dye (V5R) adsorbate, the kinetics, and adsorption isotherms are investigated. We pyrolyzed the bamboo, and calabash biomass at 500 °C, washed, and oven dried at 120 °C for 48 h. The Brunauer-Emmett-Teller (BET) method indicates that the BB and CB average pore diameters are 21.1 nm and 26.5 nm, with specific surface areas of 174.67 m²/g and 44.78 m²/g, respectively. The SEM reveals a larger granular shape of the CB having pinholes on the surface, but the BB exhibited interconnected structures like a mesh. The FTIR shows C=C, C=O, O-H, and C-O-C as the predominant functional groups on both BB and CB. The adsorption of V5R on BB and CB follows pseudo-second-order kinetics and favors Langmuir isotherm with maximum adsorption capacities of 5.106 mg/g, and 0.010 mg/g, respectively. The BB adsorbs 70.9-96% V5R, whilst CB adsorbs 0.1-0.2 % only. The results suggest that bamboo biochar has the potential to eliminate 70.9-96% of 10-50 mg/L V5R from an aqueous solution, hence suitable for removing V5R. In this study, we have also presented a prototype expected to eliminate 91.6%-99.8% of the V5R from an aqueous solution.