Biochar-based compost: a bibliometric and visualization analysis.

The co-application of biochar compost as organic amendment for crop production and soil remediation has gained momentum due to their positive effect on plant growth and soil quality improvement. The application of biochar and compost which are green and cost-effective soil remediators would promote the availability and distribution of food, planetary conservation, alleviate poverty, and enhance the attainment of Sustainable Millennium Development Goals (SDGs). A bibliometric analysis was conducted to overview research on biochar compost from 2011 to 2021. Two hundred and fifty-four research papers were retrieved from the Scopus database and analyzed using VOS viewer. Analysis revealed that 217 (85.43%) were articles, 21 (8.27%) were conference papers, and 12 (4.72%) were review papers. The results showed an exponential increase in the number of publications. The most productive countries in the investigated subject were China (49), followed by USA (36), Australia (29), Italy (28), Germany (25), and Indonesia (20). After the search terms, 'soil,' which had links with keywords like 'soil fertility,' 'soil quality,' 'soil pollution,' 'phosphorus,' 'nitrogen,' 'maize,' 'greenhouse gas,' etc., had the highest occurrences (94). From the results of the current hotspot research in the field, the effect of biochar-compost mixture and co-composted biochar on soil remediation is currently being studied by several researchers. Biochar and compost incorporation in soil reduce the uptake of pollutants by plants which consequently increase essential nutrients for plant and soil productivity.

● Biochar-compost research has been increasing for the past eleven years● China is most productive country in biochar and compost application●Biochar-compost and co-composted biochar are effective elixirs for soil amendment and nutritional enrichment.

Synthesis and Structural Studies of Manganese Ferrite and Zinc Ferrite Nanocomposites and Their Use as Photoadsorbents for Indigo Carmine and Methylene Blue Dyes.

Solar-moderated adsorptions of indigo carmine and methylene blue dyes were investigated using manganese and zinc ferrite capped with biochar prepared from the root of Chromolaena odorata. TEM micrograph of the as-prepared manganese ferrite nanocomposites (MnFe2O4@BC) revealed octagonally shaped particles with an average size of 42.64 nm while the zinc ferrite nanocomposite (ZnFe2O4@BC) micrograph revealed mixtures of rod- and cone-shaped particles with an average size of 43.82 nm. Biochar capping of MnFe2O4@BC reduced the band gap from 3.63 to 2.08 eV. The nanocomposite surface areas were 197.64 and 92.14 m2/g for MnFe2O4@BC and ZnFe2O4@BC, respectively. Photoadsorption of the as-prepared nanocomposites showed that 10 mg of ZnFe2O4@BC effectively removed 69.07 and 98.60% of 70 mg/L indigo carmine and methylene blue dyes while MnFe2O4@BC removed 77.65 and 94.83% of indigo carmine and methylene blue dyes after 2 h of equilibration under visible light irradiation, respectively. The nonlinear form of the Langmuir isotherm had a better approximation to the experimental solid-phase concentration (q e) for the adsorption of indigo carmine dye using both nanocomposites. In contrast, the linear form gave a better goodness-of-fit for the adsorptions of methylene blue dye. The manganese ferrite (MnFe2O4@BC) and zinc ferrite (ZnFe2O4@BC) nanocomposites showed no inhibition of Escherichia coli and Staphylococcus aureus, which indicates that they could be used for both biological and environmental applications.

Multifunctional Magnetic Oxide Nanoparticle (MNP) Core-Shell: Review of Synthesis, Structural Studies and Application for Wastewater Treatment.

The demand for water is predicted to increase significantly over the coming decades; thus, there is a need to develop an inclusive wastewater decontaminator for the effective management and conservation of water. Magnetic oxide nanocomposites have great potentials as global and novel remediators for wastewater treatment, with robust environmental and economic gains. Environment-responsive nanocomposites would offer wide flexibility to harvest and utilize massive untapped natural energy sources to drive a green economy in tandem with the United Nations Sustainable Development Goals. Recent attempts to engineer smart magnetic oxide nanocomposites for wastewater treatment has been reported by several researchers. However, the magnetic properties of superparamagnetic nanocomposite materials and their adsorption properties nexus as fundamental to the design of recyclable nanomaterials are desirable for industrial application. The potentials of facile magnetic recovery, ease of functionalization, reusability, solar responsiveness, biocompatibility and ergonomic design promote the application of magnetic oxide nanocomposites in wastewater treatment. The review makes a holistic attempt to explore magnetic oxide nanocomposites for wastewater treatment; futuristic smart magnetic oxides as an elixir to global water scarcity is expounded. Desirable adsorption parameters and properties of magnetic oxides nanocomposites are explored while considering their fate in biological and environmental media.

Data for experimental and calculated values of the adsorption of Pb(II) and Cr(VI) on APTES functionalized magnetite biochar using Langmuir, Freundlich and Temkin equations.

Adsorption isotherms are indispensable tools for the description of sorption processes of pollutants on adsorbents. The closeness of the equilibrium concentration (qe) to the calculated solid phase concentration (qecal) of the adsorbate, together with the co-efficient of determination (R2) and associated errors are important in determining the best goodness-of-fit model. In this work we have investigated the adsorption of Pb(II) and Cr(VI) on a nanocomposite that was prepared using magnetite nanoparticles capped with locally prepared biochar and functionalized using 3-(aminopropyl) triethoxysilane (APTES) at 3 different temperatures. Detailed discussion of data can be found in DOI:10.1016/j.micromeso.2020.110573. The sorption processes were equally analyzed utilizing both the linear and non-linear forms of Langmuir, Freundlich and Temkin equations.