Potential of agro-waste sugarcane bagasse ash for the removal of ammoniacal nitrogen from landfill leachate

Unlocking Agronutrient Resources: Sorption Strategies for sugar-energy industry waste

Vinasse and ash from sugarcane bagasse (SCB) are key byproducts in the sugar-energy industry. Vinasse is nutrient-rich but environmentally challenging, while sugarcane bagasse ash (SCBA) offers excellent adsorbent for treating effluents. This work aims to assess the effectiveness of SCBA in removing nitrogen (N) and potassium (K) nutrients from Vinasse. Simulated standard solutions of K2SO4 and (NH4)2HPO4 were used to mimic the nutrient concentrations in Vinasse and optimize experimental parameters such as adsorbent mass and contact time. Kinetic and isotherm models were also applied to elucidate the underlying adsorption mechanisms. Structural, morphological, and thermal analyses revealed the micro-mesoporous and heterogeneous nature of SCBA, primarily composed of SiO2 (quartz and cristobalite). The sorption assessment indicated the ideal conditions involved lower SCBA masses (2.5 g) and 6 h of contact time for the simulated standard solutions. The replicated conditions for Vinasse (at an adjusted sorption time of 24 h) demonstrated nutrient sorption and pH correction of the Vinasse, attributed to the alkaline nature of SCBA. Analysis of the sorption kinetic models for K+ and NH4+ revealed that SCBA interacts diffusively with the environment, not necessarily controlled by adsorption on active sites, indicating non-uniform characteristics. The sorption isotherms for K+ and NH4+ showed the non-linearized Freundlich model was the most suitable, indicating the adsorption sites with varying energy levels and a multilayer sorption process. In conclusion, we successfully demonstrated the sorption of nutrients from Vinasse by SCBA, enhancing the value of these residues and mitigating their environmental impact when used in agricultural applications.

Isotherms, kinetics and thermodynamics of industrial dye acid red 27 adsorption on Sugarcane Bagasse Ash

In this study, sugarcane bagasse ash (SCBA), obtained as residue from the sugar mill, was used as an adsorbent for Acid Red 27 (AR27) removal from aqueous solutions. The ash characterization data showed 23.63% of organic compounds and silica (α-SiO2) as the most expressive inorganic compound (confirmed by X-ray diffractogram), the BET surface area had a value of 62.79 m2.g-1 and the pHpzc was 8.45. Regarding the adsorptive tests, the optimal initial pH to the dye removal was 2.0. The adsorption equilibrium reached in about 4 h contact time and optimum SCBA dosage was found to be 4 g.L-1. The pseudo-second order model best represented the adsorption kinetics. The Freundlich equation presented the best fit to the equilibrium data for the removal of AR27 by ash, with maximum adsorption capacity of 15 mg.g-1 at pH 2.0. Thermodynamic study indicate that AR27 adsorption on SCBA occurs through a physisorption mechanism, with ΔHºads < 15 kJ.mol-1. The ΔHºads evaluated by Vant' Hoff equation was explained as a combination of water desorption enthalpy, ΔHºW and isosteric like enthalpy, ΔHºD for the dye adsorption in liquid environment. The ΔHºD = 9.2 kJ.mol-1 was calculated from Clausius-Clapeyron approach. The effects of coexisting anions on the adsorption and regeneration and reuse of the adsorbent were also investigated. This study suggests that SCBA, which was used without any pretreatment, has the potential to be applied as a low-cost adsorbent to mitigate effluents contamination with AR27 dye at low concentrations.

Biochar: A Surrogate Approach to Modulating Soil Chemical Properties and Germination Parameters of Barley Plants Grown under Multi-Stress Conditions.. [DOI: 10.21203/rs.3.rs-3216525/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Background Owing to its unique features, biochar (BC) is an excellent surrogate approach to improve the chemical properties of soil with undesirable characteristics. Methods. Under multiple abiotic stresses (ECe = 10.8 vs. 10.7 dS.m−1; CaCO3 = 19.1 vs. 18.8%; soil pH = 8.15 vs. 8.13) during two growing seasons (2020/2021 and 2021/2022), an experimental pot study was conducted to investigate the potential effects of palm tree frond biochar (PTF-BC) applied at three rates (0.0, 28.0, and 56.0 g.pot−1, labeled as BC0, BC1, and BC2) generated under three pyrolysis temperatures (350, 500, and 700 °C, labeled as PT350, PT500, and PT700). The experiment was set up according to a split-plot structure in a randomized complete block design; the pyrolysis temperatures were set as the main plot and BC addition rates were set as sub-main plots. Results. The results indicate that PT700 and BC2 had the most impact on soil chemical properties, except soil pH, which was positively affected by PT350 and BC1. Regarding the germination parameters, the data reveal that PT350 and P700 were the superior treatments, while BC2 led to noteworthy elevations of all studied germination parameters, except germination rate (GR), in both seasons. The heat map illustrating the studied soil chemical properties fluctuates between positive and negative. Conclusion. In short, the application of BC has profound desirable effects on soil physio-chemical properties relying on PTs.

Combined Effect of Biochar and Fertilizers on Andean Highland Soils before and after Cropping

Although a number of works present biochar as a promising material for improving the quality of degraded soils, only a few show the effect of this material in soils from the Andean highlands. The objective of this work was twofold: (a) to study the effect of two types of biochars on two agricultural soils commonly found in the Andean highlands (Andisol and Inceptisol) and the corresponding soil–biochar–fertilizer interactions, and, (b) to assess the response to biochar of two vegetable crops (lettuce and radish) grown in succession in a simulated double-cropping system. Biochar was produced at 400 °C and 500 °C, for 1 h (B400 and B500, respectively), using hardwood residues. Properties of biochar that could potentially affect its interaction with soil and water (e.g., functional groups, surface area, elemental composition) were assessed. Experiments were conducted to test for main and interaction effects of biochar type, soil type, and the addition of NPK fertilizer on the soils’ characteristics. Bulk density and water content at field capacity and permanent wilting point were affected by two-way interactions between biochar and soil type. Biochar impacted bulk density and water retention capacity of soils. Higher available water content was found in soils amended with B400 than with B500, which is a consequence of the higher hydrophilicity of B400 compared to B500. After the lettuce crop was planted and harvested, the soil pH was unaffected by the biochar addition. However, after the second crop, the pH in the Inceptisol slightly decreased, whereas the opposite was detected in the Andisol. The CEC of the Inceptisol decreased (e.g., from 36.62 to 34.04 and from 41.16 to 39.11 in the control and in the Inceptisol amended with B400 only) and the CEC of the Andisol increased (e.g., from 74.25 to 90.41 in the control and from 79.61 to 90.80 in the Andisol amended with B400 only). Inceptisol amended only with biochar showed decrease of radish weight, while a large increase was found in B400 + fertilizer Inceptisol (i.e., from 22.9 g to 40.4 g). In Andisol, the weight of radish after the second crop increased in less proportion (i.e., from 43 g in the control to 59.7 g in the B400 + fertilizer Andisol), showing a visible positive impact of B400. The results suggest that biochar produced at 400 °C performs better than biochar produced at 500 °C because B400 apparently promotes a better environment for bacteria growth in the soils, as a consequence of more OH available groups in B400 and its better interaction with water and the fertilizer.

Sugarcane Bagasse Ash as a Catalyst Support for Facile and Highly Scalable Preparation of Magnetic Fenton Catalysts for Ultra-Highly Efficient Removal of Tetracycline

Sugarcane bagasse ash, which is waste from the combustion process of bagasse for electricity generation, was utilized as received as a catalyst support to prepare the magnetic sugarcane bagasse ash (MBGA) with different iron-to-ash ratios using a simple co-precipitation method, and the effects of NaOH and iron loadings on the physicochemical properties of the catalyst were investigated using various intensive characterization techniques. In addition, the catalyst was used with a low amount of H2O2 for the catalytic degradation of a high concentration of tetracycline (800 mg/L) via a Fenton system. The catalyst exhibited excellent degradation activity of 90.43% removal with good magnetic properties and high stabilities and retained good efficiency after four cycles with NaOH as the eluent. Moreover, the hydroxyl radical on the surface of catalyst played a major role in the degradation of TC, and carbon-silica surface of bagasse ash significantly improved the efficiencies. The results indicated that the MBGA catalyst shows the potential to be highly scalable for a practical application, with high performance in the heterogeneous Fenton system.

Evaluation of groundwater contamination in Chandigarh: Source identification and health risk assessment

The major objective of the current study is to estimate the groundwater quality and identify the likely sources of contamination in Chandigarh, India. Total 80 groundwater samples were collected from different locations and at various depths. Further, physcio-chemical analysis was done to estimate pH, electrical conductivity (EC), total dissolved solids, total hardness (TH), total alkalinity (TA), Na⁺, K⁺, Cl^-, SO₄^2-, PO₄^3- and NO₃^-. The groundwater samples collected from shallow water sources contain higher concentration of total dissolved salts. EC, TA, Cl^-, TH, Na⁺, and K⁺ were found relatively higher in the shallow aquifer (<150 ft). Based on the location of pollution sources at the surface and consecutive geo-statistical distribution of physicochemical characteristics, this study suggests that non-scientific disposal of municipal solid waste, dumping of industrial waste and agricultural activities, in the nearby areas lead to the deterioration of groundwater of shallow aquifer. These observations were also confirmed using various water quality indices and outcomes of multivariate modeling, including principal component analysis. Health risk assessment for nitrates indicated that 29 groundwater samples pose non-carcinogenic health risk for children due to dermal and oral exposure. Hence, there is a need to establish a system for regularly assessing the groundwater quality to minimize public health risks.