Pristine wild sugarcane (Saccharum spontaneum) as a biosorbent for removal of methylene blue from wastewater: isotherm, kinetics and regeneration studies.

Saccharum spontaneum, popularly known as Kashful (KF) is a seasonal perennial grass with thin culms, mostly an abundantly growing shrub during the autumn season in southern Asia. It is used as no-cost scavenger to convincingly arrest methylene blue, a recalcitrant dye from colored effluent. FTIR, FESEM-EDX, and BET surface area characterize the material well whereas the surface activity was evaluated from zero-point charge (pHZPC = 6.720). FTIR highlights the presence of polyphenolic and carboxylate moieties. The surface texture is rod-like with intermittent non-homogeneous pores with occasional fractures. The equilibrium reaches within 60 min with the maximum adsorption capacity of 20.917 mg/g. The fibrous powder of kashful stalk (KFS) follows pseudo-second-order (R2 = 0.999 for linear and R2 = 0.985 for non-linear) kinetics and both Langmuir and Freundlich isotherm model (for linear, Langmuir R2=0.995; for non-linear, R2 = 0.994 for both Langmuir and Freundlich model). The uptake process was spontaneous (ΔG= -3.077 kJ/mol) and endothermic (ΔH = 17.815 kJ/mol). 1:1 methanol could regenerate the dye-loaded material in up to 55% and onward efficiency was conducive for three consecutive cycles. Industrial effluent analysis suggests a real-time removal of ∼55% in the first cycle. Saccharum spontaneum could be exercised to solve environmental problems related to colored water.

Saccharum spontaneum, also known as wild sugarcane is an abundantly available long grass with relatively slender culms; usually 100­150 cm tall, grows in the autumn season (August-October) in the south-east part of Asia, and displays steady tillering. Being a non-preferred meal for local herbivores, the material lies abandoned as bio-waste. At the same time, the search for a newer and cleaner alternative for wastewater treatment is on the rise. In line with the waste-to-wealth protocol for a sustainable environment, we have demonstrated the facile uptake of a recalcitrant dye methylene blue (20.917 mg/g) using its stalks powder. The present method is free from any hazardous chemical activation, acid-base treatment, or pyrolysis. With the ability to treat industrial effluent, the material highlights an impactful application in a lab-to-land fashion.

Neolamarckia cadamba (cadamba) waste pulp as a natural and techno-economic scavenger for methylene blue from aqueous solutions.

In this work, Neolamarckia cadamba (cadamba), also known as bur flower tree has been exercised to demonstrate as an excellent methylene blue scavenger from simulated as well as industrial wastewater. The particle morphology and structural insights were gained from FESEM, BET surface area, FTIR, and pHZPC. The adsorption behavior was mapped by different physico-chemical parameters such as contact time, pH, input concentration, and temperature. Experimental data reveal rapid adsorption, and >90% uptake was successful within the first 15 min and reaches equilibrium by 45 min (removal efficiency = 94.15%) at neutral pH. The maximum adsorption capacity was found to be 115.60 mg/g. The uptake process follows pseudo-second-order kinetics (R2 = 0.99), confirming a chemisorption process while the Langmuir model (R2 = 0.99) satisfactorily addresses the adsorption path. Thermodynamic parameters suggest a spontaneous, feasible, and exothermic process with increased entropy. Spent adsorbent could easily be regenerated in up to 74% using 1:1 MeOH/H2O with a potential of three-cycle use. Real-time efficacy has been established with an MB containing industrial effluent and up to 44.70% adsorption, which confirms the material's practical applicability. Statistical reliability was confirmed by the relative standard deviation. Altogether, the present material offers clean and green removal of methylene blue dye from versatile wastewater.

The search for cleaner and greener protocols for water treatment is on the rise. With this line, we have chosen non-edible fruit pulps of Neolamarckia cadamba for extraordinary methylene blue uptake from diverse contaminated water bodies. Compared to contemporary materials, the excellent adsorption capacity (115.60 mg/g) with methylene blue dye offers an edge. The material could be regenerated easily and reused for three cycles. The method doesn't involve any chemical treatment, is greener, and could be applied on a large scale. Due to huge availability, excellent adsorption capacity, reusability, and simple preparation provide advantages to the material for sustainable water treatment.

Non-conventional, burnt Shorea robusta leaf extract mediated green synthesis of zinc oxide nanoparticles and facile removal of eriochrome black T dye from water.

The present study evaluates the synthesis of zinc oxide nanoparticles (ZnO NPs) using water extract of Sal leaves (Shorea Robusta) for efficient removal of Eriochrome black-T from the water and wastewater. The material is characterized using FESEM, FTIR, EDX, pHzpc, XRD, BET, and TGA analysis. XRD confirmed the synthesis of ZnO with an average crystallite size of 35.24 nm a surface area of 95.939 m2/g and a pore volume of 0.280 cm3/g. The pHzpc of the material is 7.45. The study evaluates the effects of contact time (0-100 min), pH (3-10), concentration (10-50 mg/L), and temperature (298-328K). The Langmuir isotherm model (R2 = 0.993) and pseudo-second-order kinetic model (R2 = 0.998) were found to be the best-fit models. The maximum uptake capacity is 265.554 mg/g. The interaction is spontaneous (ΔG° -12.889 to-14.898 kJ/mol), endothermic ΔH° (4.290-14.216 kJ/mol) with an increase in spontaneity at the solid-liquid junction. The dye-loaded ZnO NPs were successfully regenerated in dilute NaOH solution and 1:1 methanol water, achieving regeneration efficiencies of 78% and 60%, respectively. The reusability of the ZnO NPs was ascertained for up to three consecutive cycles.

A promising method for synthesizing zinc oxide nanoparticles using water extract from burnt Shorea robusta leaves as a precipitating and capping agent has been demonstrated with a high yield. The method is economical and convenient without the use of any chemical precipitating agents. The prepared material efficiently removes Eriochrome black T dye, commonly used in various industries for dyeing silk and nylon, from the solution.We report the first-ever synthesis of ZnO NP using the water extract of burnt leaves, and its application is tested for dye removal. A high surface area of 95.939 m²/g was determined, which is also higher in comparison to many works published. The maximum adsorption capacity recorded for EBT removal is 265.55 mg/g, which is relatively higher than other commercially synthesized zinc oxide.

Augmented dye eradication from wastewater using alkali-aided, reinforced waste acacia (Acacia auriculiformis) leaves.

The present investigation demonstrates the augmented dye scavenging from wastewater using alkali-mutated acacia (Acacia auriculiformis) leaves powder. The material was synthesized by mild chemical activation by using 0.1 M sodium hydroxide as an activator under room temperature stirring for 3h and isolated as a dark brown powder. The material was characterized using FTIR, FESEM, XRD, and pHzpc; and tested successfully with crystal violet and methylene blue. While FTIR confirms the presence of polyphenolic and polysaccharide moieties, FESEM reveals unprecedented circular hollow pipe-like channels decorated in a highly ordered fashion, facing pores for optimum dye uptake. The adsorption is tunable with working pH, and the maximum adsorption capacities are 67.25 and 78.55 mg g-1 for CV and MB. Both adsorption process follows Langmuir isotherm (R2 = 0.994) and pseudo-2nd-order kinetics (R2 = 0.999). Thermodynamic analysis verifies a spontaneous process with an endothermic interaction beside an elevated degree of randomness. About 80% of the spent material could be regenerated using 1:1 methanol/water. Analysis of industrial effluent suggests 37% removal per cycle, with an operating ceiling of 95%. To wind up, due to huge availability, porous nature, and superior adsorption capacity over other phytosorbents, NaOH-activated acacia leaves could be considered as techno-economic and potential scavengers for sustainable water treatment.

Lignocellulosic waste plant litters have enormous potential for biosorption of heavy metals and dyes for their economic viability and environment-friendly nature. The present investigation highlights the promising cationic dye scavenging ability of alkali-treated waste acacia (A. auriculiformis) leaves from simulated and industrial wastewater. With adsorption capacities of 67.25 and 78.55 mg g⁻¹ for crystal violet and methylene blue respectively, the protocol shows promise in colored water treatment. Easy preparation, classy removal efficiency, and recyclability offer the key advantage with a techno-economic impact.

Towards a win-win chemistry: extraction of C.I. orange from Kamala fruit (Mallotus philippensis), and simultaneous exercise of its peels for the removal of Methylene Blue from water.

Kamala fruit (Mallotus philippensis), hereinafter MP, has been simultaneously exercised for the extraction of a natural dye, C.I. orange and its peels were converted into an efficient adsorbent for the rapid removal of methylene blue (MB) dye from aqueous solutions. The material has been characterized by Fourier Transform Infra-red (FTIR),Field Emission Scanning Electron Microscopy- Electron dispersive spectroscopy (FESEM-EDS), Brunauer-Emmett-Teller (BET) surface area, and pHZPC. FTIR suggests the presence of polyphenolic moieties responsible for adsorption, whereas FESEM confirms the porous texture. Optimization of process variables such as contact time, pH, adsorbent dose, and temperature of operation indicates that the adsorption gets modulated by the pH, with a best at 11. The Freundlich model (R2 = 0.994), and pseudo-second-order kinetics (R2 = 0.999) best describe the adsorption pathway. Dilute hydrochloric acid is sufficient to induce >66% regeneration, which ensures reusability. With the maximal uptake for MB is 30.2 mg/g at ambient conditions, the superiority over the existing materials has been confirmed. Treatment of dye containing industrial effluent suggests about a 50% reduction in one cycle. It can be concluded that both-way benefits, namely natural dye extraction and preparation of a peel-based adsorbent for methylene blue removal from aqueous solution, can be achieved using the kamala fruit peels.

Mallotus philippensis, a seasonal fruit, commonly known as Kamala, was employed to serve a dual advantage of extracting a natural dye called C.I. orange from the peels; thereinafter, the peels were converted as an adsorbent to remove Methylene blue from water and industrial wastewater with high efficacy. From 100 g of raw material, 1.7 g of C.I. orange dye was extracted, along with 44 g of peel-based adsorbent. The maximum adsorption capacity for MB is 30.2 mg/g at ambient conditions, better and more impactful than contemporary adsorbents. The approach is firmly established in the circular economy as a dual benefit agent, generating clean and green revenue through natural dye extraction.

Exploring the promising potential of fallen bamboo leaves (Bambusa bambos) for efficient removal of crystal violet from wastewater.

Fallen bamboo leaves (Bambusa bambos), hereinafter BL have been designed to be transformed into an efficient and sustainable adsorbent for the removal of crystal violet (CV) dye from wastewater with up to 95% scavenging ability. BL have been characterized by Fourier transform infrared (FTIR) spectra, field emission scanning electron microscopy (FESEM), and zero point charge (pHzpc). The maximum adsorption capacity is 30 mg/g at pH 10. Physico-chemical parameters have been investigated concerning pH, contact time, initial concentration, and coexistent ions. Pseudo-second-order kinetics is followed best (R2 =0.999) signifying a chemisorption pathway. Besides, intra-particle diffusion plays a governing role in the film diffusion of crystal violet into the core of the adsorbent. Langmuir isotherm model fits best (R2=0.972) suggesting a uniform, monolayer, and homogeneous adsorption. Regeneration was successful with methanol (65%) and reusability was tested for three cycles and was found to retain activity up to 80%. Analysis of CV containing industrial effluent suggests that a 36.8% reduction is possible with BL. The effect of co-existent ions suggests little influence on the adsorption. Compared to other contemporary and relevant adsorbents, it can be concluded that BL can be exercised for the sustainable decontamination of CV-containing wastewater.

Bambusa bambos, the giant thorny bamboo is an abundantly available plant throughout the year, has been successfully exercised using its fallen leaves to scavenge crystal violet, a cationic dye from water and wastewater. Up to 95% adsorption was noticed at ambient conditions, which when further extrapolated for industrial effluent analysis, shows a remarkable 36.8% decontamination/cycle. With an adsorption capacity of 30 mg/g, it enjoys an edge over contemporary phytosorbents. The process is free from any chemical treatment, green in nature, and sustainable. Abundant availability and economic viability allow an impactful application of fallen bamboo leaves for water and wastewater treatment in a lab-to-land sequence.

Brinjal (Solanum melongena) stalk waste as an effective scavenger for Eriochrome Black-T from water and wastewater: an approach towards waste to best.

Stalks of brinjal (Solanum melongena), hereinafter SM, have been exercised as an efficient and sustainable adsorbent material for the elimination of Eriochrome Black-T (EBT) from an aqueous solution. The material was characterized by FTIR, FESEM, BET surface area, pHpzc, and proximate analysis. FTIR spectrum suggests the presence of polyphenolic moieties, responsible for successful dye binding. FESEM images show an unprecedented octopus-like texture containing micropores. The central head transforms the architecture of a flower. The evaluated BET surface area of 10.042 m2/g and pore volume 1.055 × 10-2 cm3/g suggest a porous material. The pHpzc of the material was evaluated to be 7.05, and under optimized conditions, the maximum adsorption capacity was found 52.631 mg/g at pH 7. The operational parameters were studied concerning contact time (0-90 min), pH (5-11), initial concentration (10-40 mg/L), and interfering ions (PO4-3, AsO4-3, Hg+2, Pb+2). Adsorption follows Langmuir isotherm best (R2 = 0.996), and pseudo-second-order kinetics (R2 = 0.991) indicate a monolayer and homogeneous adsorption. 83% regeneration was successful with 0.1(M) sodium hydroxide solution. The material can be reused for up to three cycles with 90% efficiency retention. Analysis of EBT containing industrial effluent indicates that 52.62% of EBT can be removed.

Brinjal (Solanum melongena), being one of the most cultivated vegetables around the globe, generates voluminous waste as stalks which warrant proper management. With this aim, such stalks were converted to a phytosorbent and selected for removal of Eriochrome black-T (EBT), a dye that is used by industry persons and science students in their laboratory experiments. The prepared material is highly porous, water-stable, regenerable, and reusable. The protocol is economically viable, easy, and efficient for industrial effluent treatment as well. With a notable maximum adsorption capacity of 52.631 mg/g, the material could offer an ideal choice for dye decontamination.

Thiosulfate impregnated spent tea leaves for the remarkable uptake of malachite green.

Herein we demonstrate an enhanced performance of acid-assisted thiosulfate-impregnated spent/waste tea leaves (TWTL) for the removal of malachite green (MG) from water by batch mode. The material was characterized by pHZPC, FTIR, powder XRD, SEM, and proximate analysis. FTIR suggests the presence of polyphenolic moieties whereas a lignocellulosic peak was observed in powder XRD. SEM image shows a grafted surface texture with intermittent blocks, which upon dye uptake becomes somewhat condensed. Under optimized conditions, the highest removal efficiency of 126.8 mg/g was achieved at pH 7. A fast adsorption process was noticed with >97% removal within the first 10 min. Adsorption follows pseudo-second-order kinetics (R2 = 0.999) and the Langmuir model (R2 = 0.999). The material can be regenerated by dilute hydrochloric acid and can be reused for up to four cycles. Treatment of industrial effluent was successful in up to 47.56%. Our results highlight the potential of thiosulfate-treated spent tea leaves as a choice for the efficient removal of malachite green from water.

Tea, being one of the most popular beverages produces huge waste which requires proper management. With this aim; the thiosulfate-impregnated spent tea leaves have been exercised for effective separation of malachite green from contaminated water. Thiosulfate impregnation under mildly acidic conditions activates the tea leaves and makes the material robust with enhanced water stability than its untreated variety. With a remarkable maximum adsorption capacity of 126.8 mg/g under ambient conditions, the present methodology enjoys the edge over related phytosorbents. The protocol is techno-economic, environment friendly, and could be extended to possible field applications.