The Effect of Iron-Modified Biochar on Phosphorus Adsorption and the Prospect of Synergistic Adsorption between Biochar and Iron-Oxidizing Bacteria: A Review

Abstract

The release of endogenous phosphorus (P) from sediments is the main cause of lake eutrophication, even after the successful control of exogenous P. Among others, the release of iron-bound P is a major source of endogenous P, and it is necessary to reduce the P concentration by enhancing iron–phosphorus binding. Iron (Fe)-modified biochar adsorption is an effective and widely used method for fixing P in sediments. In this paper, the modification method, mechanism, and application effect of Fe-modified biochar are reviewed. It is found that most of the modification methods are realized through a physicochemical pathway. Therefore, the prospect of biochar modification through a biological pathway is presented. In particular, the possible application of iron-oxidizing bacteria (IOB) for promoting iron–phosphorus binding and biochar modifications is discussed. The potential effects of biochar additions on microbial communities in water and sediments are also discussed. In the future research, emphasis should be placed on the adsorption mechanism and effect analysis in simulated polluted environments before large-scale use, to ensure the economic practicability and sustainability of Fe-modified biochar applications.

Degradation of Phenol by Immobilized Alcaligenes faecalis Strain JH1 in Fe3O4-Modified Biochar from Pharmaceutical Residues

“…In general, the increase in specific surface area values at high-pyrolysis temperatures is mainly due to the removal of volatiles. During pyrolysis, the rapid release of volatiles opens and connects blind and closed pores, as well as forms new cracks, micropores, and mesopores, leading to a significant increase in specific surface area [28]. Figure 1 shows the N 2 adsorption-desorption isotherm curves of the four biochars.…”

“…Therefore, these results suggest that the removal of phenol by biochar-immobilized A. faecalis JH1 is a synergistic effect of adsorption and bacterial degradation, and that biochar itself can adsorb a large amount of phenol, and therefore increase the chance of bacterial contact with phenol and promote bacterial degradation of phenol. In addition, the large number of pores in the biochar provides an important habitat for microorganisms [26] and provides them with shelter, which reduces the toxicity of phenol to microorganisms, and at the same time, the biochar can stimulate the growth and activity of microorganisms, and microorganisms can utilize the ash of the biochar to provide mineral nutrients [28]. After the phenol in solution was degraded within 24 h, the enzymatic activity of the bacteria in solution was measured, as shown in Figure 6b.…”

Facet-Dependent Adsorption of Phosphate on Hematite Nanoparticles: Role of Singly Coordinated Hydroxyl

“…Phosphorus is an essential nutrient in natural ecosystems and is widely used in human life, industrial and agricultural production processes [1,2]. However, excessive phosphorus discharges are responsible for eutrophication of water bodies, leading to deterioration of water quality and posing serious risks to biodiversity and human health [3,4]. Therefore, it is particularly important to understand the processes of phosphorus enrichment, transport and transformation in water bodies.…”