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AbstractIn this work, the biowaste of Musa paradisiaca (Banana) was used for removing contaminants from water by adsorption on a batch scale using Congo red (CR) dye as a test case. Although banana peel adsorbents have been the subject of much research for a range of applications, including the removal of colors from wastewater, our study differs from others in that we treated the banana peel adsorbent with hydrogen peroxide (H2O2), which significantly enhanced its performance when compared to untreated banana peel powder. By eliminating organic contaminants, discoloring the sample, inhibiting the growth of bacteria or fungi, and raising the quantity of active sites accessible for dye adsorption, the H2O2 treatment increases efficiency. The results indicated that optimal conditions for CR dye removal with physio-chemically processed Musa paradisiaca biowaste were: pH 3, adsorbent dose 0.4 g, temperature 30 °C, and contact time 25 min. Equilibrium data were evaluated with isothermal and kinetic models, indicating that the data followed second-order kinetics with a correlation coefficient of R2 = 0.995 with a maximum dye removal of 8.577 mg/g. Furthermore, the study found that CR dye removal was physiochemical and exothermic process, as confirmed by the experimental data, with a ΔGo of −6.992 kJ/mol. The results of this study suggest that this fabricated material of Musa paradisiaca biowaste could be a potential alternative for large-scale Congo red dye elimination from industrial effluents. This is both a sustainable and cost-effective solution. [ABSTRACT FROM AUTHOR]

A rapidly growing problem for life on earth is contamination of fresh water which is addressed in this article. By taking a glimpse on the causes of contaminations, persistent organic pollutants, especially synthetic dyes got prominent role. Here, out of commonly used techniques, adsorption using plant wastes was chosen for phytofiltration of such dyes. A natural adsorbent from plant source was selected and processed with acid, characterized with FTIR and SEM and then checked the efficacy on cationic dye brilliant green. Phytofiltration of dye was done to check the effectivity of both untreated (OA) and acid treated (OA-AC) form of Acacia concinna biowaste. Results were obtained, evaluated and presented here, giving maximum adsorption capacities (Qm) of AC and OA-AC 95.24 and 909.09 mg.g−1, respectively following Langmuir, pseudo second order kinetics and spontaneous exothermic nature, indicating their suitability to adopt on larger scale wastewater treatment effectively using green technology. NOVELTY STATEMENT: In this work, Acacia concinna both in untreated and acid treated form is used as an efficient adsorbent for the removal of Brilliant green dye from waste water, as not reported earlier, which proves its novelty. The values of adsorption capacities of both the adsorbent types are compared with different natural and synthetic adsorbents reported earlier, this comparison elaborate the efficacy of AC to be used as adsorbent and consider it as one of the efficient adsorbent materials naturally available. [ABSTRACT FROM AUTHOR]

Water pollution is a grave risk to mankind. Water pollutants including organic toxins, dyes effluents, and heavy metals have posed great stress on water quality in recent years. This has necessitated the search for an affordable, eco-friendly, inexpensive, stable, and effective strategy for wastewater remediation. In this work, a pollyoxometallate K6[H2AlBW11O40].9H2O (KAB) was impregnated on kaolin clay to synthesize a clay-based nanocomposite KAB-K which was then evaluated for adsorptive removal of brilliant green dye (BG) from wastewater. The prepared composite was characterized by different techniques such as FTIR, SEM, and EDX analysis. The characterization results indicated the fine distribution of KAB on kaolin's surface. The adsorption studies of BG involved evaluation of optimum parameters such as time contact (30 min), quantity of adsorbent (20 mg), pH (5), temperature (40 °C), and agitation speed (125 rpm). 99.5% of BG was removed by KAB-K within 30 min. The assessment of kinetic data was performed via Langmuir, Freundlich, and Temkin models. The experimental data was found to be in good agreement with the Langmuir model (R2 > 0.9965) as compared to other models. Qmax value of KAB-K (144.92 ± 0.005 mg/g) was much higher than simple kaolin (33.22 ± 0.01 mg/g). The applicability of the pseudo-second-order kinetic model suggested that the process was predominately chemisorption. KAB-K was easier to recycle and efficiently removed up to 68.7% dye in 3 subsequent cycles. Thus rapid adsorption rate, high adsorption capacity, efficient recovery, and reusability of KAB-K endorses that the synthesized composite is an effective adsorbent for wastewater pollutants. [ABSTRACT FROM AUTHOR]

AbstractAntibiotics, posing a major threat to life on earth and water causing propagation of antibiotic resistant bacteria and antibiotic resistant mutant genes. Traces of these antibiotic toxins are found both in aquatic as well as terrestrial ecosystem. Various techniques, that is, ozonation, membrane filtration, Fenton process, etc., are applied for their removal but have many shortcomings, so adsorption is picked as efficient, simple and relatively safe removal technique. This review article discusses the classification of antibiotics, effect of their unnecessary application and removal methods of their remnants from water sources. Also, compares adsorptive removal of antibiotics remnant with other primitive and advance techniques, suggesting adsorption as one of the effective techniques. [ABSTRACT FROM AUTHOR]

Pakistan is an agricultural country producing plenty of fruits, like: mango, banana, apple, peaches, grapes, plums, variety of citrus fruits including lemon, grapefruit, and oranges. So far the peels of most of the fruits are usually wasted and not properly utilized anywhere. In this work, the peels of banana and grapefruit are converted into biochar by slow pyrolysis under controlled supply of air and used for sequestering cyanide ions from aqueous medium after chemical modification with ZnCl2 and sodium dodecyl sulfate (SDS). The modified biochar was characterized by various instrumental techniques, like: SEM, FTIR, TGA, and CHNS. Different parameters, like: time, temperature, pH, and dose of adsorbent affecting the adsorption of cyanide ions, onto prepared biochar were optimized and to understand the adsorption phenomenon, kinetic and thermodynamic studies were performed. Concentration of cyanide ions was estimated by employing standard ion selective electrode system and it is found that Sodium Dodecyl Sulfate treated biochar of banana peels shown more adsorption capacity, i.e.,: 17.080 mg/g as compared to all samples. Present work revealed that the biochar produced from the fruit waste has sufficient potential to eliminate trace quantities of cyanide from water, especially after treatment with sodium dodecyl sulfate. An industrial area in Asian and African countries where mining is done using traditional techniques is the major cause of cyanide toxicity in wastewater streams. So, here chemically fabricated biochar made by peels of banana and grape fruit is employed for removal of cyanide ion for controlling aquatic pollution using local resources in green way. Favorable results indicated the feasibility of this process, which is cost effective, convenient, ecofriendly, and sustainable. [ABSTRACT FROM AUTHOR]

Microalgae technology is a viable solution for environmental conservation (carbon capture and wastewater treatment) and energy production. However, the nutrient cost, slow-kinetics, and low biosorption capacity of microalgae hindered its application. To overcome them, algal-biochar (BC) can be integrated with microalgae to treat textile wastewater (TWW) due to its low cost, its ability to rapidly adsorb pollutants, and its ability to serve as a nutrient source for microalgal-growth to capture CO2 and biodiesel production. Chlorella vulgaris (CV) and algal-BC were combined in this work to assess microalgal growth, carbon capture, TWW bioremediation, and biodiesel production. Results showed the highest optical density (3.70 ± 0.07 OD680), biomass productivity (42.31 ± 0.50 mg L−1 d−1), and dry weight biomass production (255.11 ± 6.01 mg L−1) in an integrated system of CV-BC-TWW by capturing atmospheric CO2 (77.57 ± 2.52 mg L−1 d−1). More than 99% bioremediation (removal of MB-pollutant, COD, nitrates, and phosphates) of TWW was achieved in CV-BC-TWW system due to biosorption and biodegradation processes. The addition of algal-BC and CV microalgae to TWW not only enhanced the algal growth but also increased the bioremediation of TWW and biodiesel content. The highest fatty acid methylesters (biodiesel) were also produced, up to 76.79 ± 2.01 mg g−1 from CV-BC-TWW cultivated-biomass. Biodiesel's oxidative stability and low-temperature characteristics are enhanced by the presence of palmitoleic (C16:1) and linolenic (C18:3) acids. Hence, this study revealed that the integration of algal-biochar, as a biosorbent and source of nutrients, with living-microalgae offers an efficient, economical, and sustainable approach for microalgae growth, CO2 fixation, TWW treatment, and biodiesel production. [ABSTRACT FROM AUTHOR]

AbstractThe use of biopolymers and synthetic adsorbents for wastewater treatment is gaining more importance due to their ease of preparation and nontoxic nature. This study focuses on developing a new biopolymeric composite using Polyaniline and a leafy mulch of mango plants (PANI/ML) and applied to remove an anionic dye, i.e.: Direct Red-28 from water on a lab scale. Samples were characterized by various spectrochemical methods, like FT-IR, UV–Vis, and SEM analysis, and then used for adsorption studies. Results indicated that PANI/ML nanomaterial removed 203.25 ± 0.57 mg/g of Direct Red-28 dye, following chemisorption and pseudo-2nd order kinetic model with inter-layer diffusion mode. Desorption studies indicated that it can be recycled three times effectively. So, this composite can be used for adsorptive bioremediation of synthetic anionic pollutants. [ABSTRACT FROM AUTHOR]

In this work, we explored the adsorptive detoxification potential of titania–bentonite clay composite for removing a cationic dye (crystal violet) from aqueous medium. Fresh clay composite sample were prepared by impregnated method, followed by spectroscopic characterization by SEM, FTIR, and EDX. After that, in batch studies dye removal were examined. The results under optimum conditions showed that this composite material has a 96% elimination capacity. Maximum removal of crystal violet was 49.26 mg/g, following Pseudo-second order kinetic model occurred at pH 8, at 125 rpm and 25 ppm initial concentration at 45 °C. Kinetics of reactions and isotherm models were investigated. Adsorption data showing the presence of monolayer adsorption were fitted using the Langmuir isotherm model. Chemisorption was shown to prevail according to Temkin isotherm criteria. Pseudo-second-order kinetics was followed in this case. For removing dye from industrial effluents, this titania–bentonite composite serves as a nonbiodegradable, low-cost, reliable, and ecologically safe adsorbent. [ABSTRACT FROM AUTHOR]

Textile industries use large amounts of water as well as dyes. These dyes containing water are then discharged into the water bodies causing a significant role in water pollution. Brilliant Green dye contributes to many harmful diseases related to the respiratory and gastrointestinal tract. In this study, Symplocos racemosa (SR) agro-waste was chemically treated with acid (SR-HCl) and base (SR-NaOH) and then used for removing Brilliant Green Dye (BGD) on the batch scale. They were characterized by SEM, EDX, FTIR, XRD, TGA and DSC. Optimized conditions were 30 °C temperature, pH 6, adsorbent dose of 0.10 g/25 ml dye solution, shaking speed of 100 revolutions per minute, initial dye concentration of 50 ppm and 35 min time for shaking adsorbent and dye solution. Adsorption data obtained were analyzed using isotherms. The experimental data was found to fit well with the Langmuir model and the maximum adsorption capacity (qmax) of BGD on the SR, SR-HCl, and SR-NaOH was revealed to be 62.90, 65.40, and 71 mg/g respectively. Kinetic data (pseudo-first-order and pseudo-second-order) were evaluated and adsorption tends to follow the pseudo-2nd-order, which indicated the chemisorption mechanism. The results revealed that Symplocos racemosa agro-waste can be considered as the potential biosorbent. [ABSTRACT FROM AUTHOR]

AbstractThe impregnation of titania causes to generate and activate more points on surface of bentonite which is usually slightly basic in nature. That helps in the removal of cationic impurities effectively. So, their composite (TBC) is prepared and used to remove brilliant green (BG) dye as a test case here in cost-effective and ecofriendly manner by green methodology. The surface modification was analyzed by FTIR and SEM/EDX. Adsorption parameters were investigated and found that 4.54 mg/g ± 0.73 S.D of dye was removed by this composite using optimized condition. In kinetic study, pseudo-second order model justified the data. Thermodynamic value is −10.33 kJ/mol ± 0.067 indicating its exothermic and spontaneous nature of process. Desorption of BG and regeneration of titania–bentonite composite with HCl helps in its recycling and affirms that these nanocomposites are prolific, high-yielding and resourceful material for dye removal during wastewater treatment. [ABSTRACT FROM AUTHOR]