Potential of yak dung-derived hydrochar as fertilizer: Mechanism and model of controlled release of nitrogen

Fe3O4 loaded on ball milling biochar enhanced bisphenol a removal by activating persulfate: Performance and activating mechanism

In this study, pristine biochar (BC), ball milling biochar (MBC), Fe₃O₄ modified BC (Fe₃O₄@BC), and Fe₃O₄ modified MBC (Fe₃O₄@MBC) were prepared to compare the Bisphenol A (BPA) removal efficiency by activating persulfate (PDS). All catalysts exhibited excellent degradation rather than adsorption in the PDS system, and Fe₃O₄@MBC800 had the best BPA removal efficiency, with 96.73% degradation and negligible 1.43% adsorption due to the synergistic effect between MBC800 and Fe₃O₄ particles. Radical quenching experiments and electron paramagnetic resonance analysis indicated radical pathways, namely, SO₄∙^- and ∙OH, O₂∙^-, and non-radical pathway (¹O₂) involving BPA degradation. The abundant oxygen-containing groups, increased graphitization and mesopores of MBC800, and Fe³⁺/Fe²⁺ conversion of Fe₃O₄ particles facilitated PDS activation to produce reactive oxygen species. In addition, the superior electrochemical performance accelerated the electron transfer between the catalyst and PDS, promoting BPA degradation in the Fe₃O₄@MBC800/PDS system. More importantly, Fe₃O₄@MBC800 is resistant to environmental interference, including pH, anions, cations, and humic acid, and has good catalytic reusability and stability, which fulfills the requirements of engineering applications. Therefore, Fe₃O₄ loaded on ball-milled biochar provides a convenient strategy for preparing environmentally friendly, economical, and efficient carbon-based catalysts to remove organic contaminants.

Effect of the Combining Corn Steep Liquor and Urea Pre-treatment on Biodegradation and Hydrolysis of Rice Straw

A novel pre-treatment using corn steep liquor (CSL) and urea was developed to enhance the enzymatic saccharification and degradability of rice straw (RS). We used RS (1) without (Con) or with additives of (2) 5% urea (U), (3) 9% CSL and 2.5% urea (CU), and (4) 9% CSL and 5% urea (C5U). The result showed that the water-soluble carbohydrate (WSC) conversion of RS reached 69.32% after C5U pre-treatment. Scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and X-ray diffraction analysis (XRD) confirmed that the surface of pre-treated RS exposed more cellulose and hemicellulose due to the disruption of the resistant structure of lignocellulose. Pre-treated RS significantly decreased neutral detergent fiber (NDF) and acid detergent fiber (ADF) contents and increased crude protein (CP) content, microbial colonization, and induction of Carnobacterium and Staphylococcus attachment. Altogether, we concluded that pre-treatment of a combination of CSL and urea has the potential to improve the nutritive value of RS.

Sustainable biochar-based soil fertilizers and amendments as a new trend in biochar research

Today's world is struggling with many environmental problems. Due to the ever-growing size of the population, it is necessary to produce more and more food. The consequence of such a large demand for food is excessive fertilization of soils, often in an uncontrolled manner. The paper presents an overview of the different types of biochar (BC) fertilizers obtained by: coating BCs with a protective layer, coating commercial fertilizers with a layer of BCs, or mixing BCs with commercial fertilizers. Although the use of these new types of fertilizers has a positive effect on soil properties and crop yields, the production and use of "simple" inorganic fertilizers are dominant. The solution to starting the change of this trend may be the use of BC-compost systems as an effective soil amendment, due to the fact that composts are still the most frequently used products by farmers. The review summarized two types of BC-compost soil amendments: BC mixed with ready-made compost and BC co-composted with compost raw material. These types of soil amendments contribute to a significant reduction in the consumption of commercial inorganic fertilizers, and thus less pollution of the natural environment, while allowing for a high yield of safe food.

Preparation and characterization of biochar derived from co-pyrolysis of Enteromorpha prolifera and corn straw and its potential as a soil amendment

Single biomass feedstock approach may not meet the requirements for developing biochar with desired characteristics for use as soil amendment. In this study, biochars were prepared by co-pyrolysis of nutrients-rich Enteromorpha prolifera and lignocellulose-rich corn straw (CPECs) at different mass ratios (3:7, 1:1, and 7:3). CPECs presented higher water-soluble N/P contents than corn straw biochar, and exhibited larger surface area, low Na content, and slower nutrient release rate than Enteromorpha prolifera biochar. The modification in physicochemical and properties of CPECs enhanced its potential application as a soil amendment. A pot experiment showed that CPECs derived from co-pyrolysis of appropriate ratios of Enteromorpha prolifera and corn straw (1:1, 7:3) significantly increased the biomass of cherry tomato plant by 64.05%, 40.03% and 81.88%, 55.25%, when compared with corn straw biochar and Enteromorpha prolifera biochar, respectively. The positive effects of CPECs were primarily attributed to improved soil properties (e.g., water holding capacity, soil organic matter, pH, soil nutrients content) and increased total N/P uptake by plants. The results of this work provided potentials of developing "designer" biochars to meet the multiple soil requirements by co-pyrolysis.