Bioremediation of soils contaminated with polycyclic aromatic hydrocarbons, petroleum, pesticides, chlorophenols and heavy metals by composting: Applications, microbes and future research needs

https://hal.archives-ouvertes.fr/hal-01436218/document

Foliar heavy metal uptake, toxicity and detoxification in plants: A comparison of foliar and root metal uptake.

Heterogeneous Fenton reactions have gained widespread attention in removing recalcitrant organic contaminants as the reaction between solid Fenton catalysts and H2O2 can generate highly reactive hydroxyl radicals (HO[rad]). However, several drawbacks, such as the low-speed generation of Fe(II), high consumption of H2O2, and acidic reaction conditions (generally at ˜ pH 3), are always the core issues that hamper the large-scale application of heterogeneous Fenton reactions in environmental remediation. Thus, a large number of studies have been devoted to tackling these drawbacks, and this paper intends to comprehensively review the developed strategies for enhancing heterogeneous Fenton reactivity, mainly over the last decade. Based on a comprehensive survey of previous studies, we categorize these strategies according to their reaction mechanisms. For example, introducing additional electrons (e.g., from external electric fields, electron-rich materials, semiconductors, plasmonic materials, or doped metals) to heterogeneous Fenton catalysts can accelerate the generation of Fe(II); the in situ generation of H2O2 can be achieved by combining ultrasound, electricity, semiconductors, and iron-based catalysts in the system; and controlling the specific morphologies and exposed facets of heterogeneous Fenton catalysts can greatly promote the decomposition of H2O2. In addition, we briefly introduce some recent novel heterogeneous Fenton-like reactions that are of particular interest, including constructing dual reaction centers (i.e., the electron-poor center and the electron-rich center) and synthesizing single-atom catalysis-based heterogeneous Fenton-like catalysts. Moreover, this review article analyzes and compares the merits of each strategy for enhancing heterogeneous Fenton/Fenton-like reactions. We believe this review can motivate the construction of novel and efficient heterogeneous Fenton/Fenton-like systems and help readers choose proper Fenton/Fenton-like reaction systems for industrial applications.

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Strategies for Enhancing the Heterogeneous Fenton Catalytic Reactivity: A review

Graphitic carbon nitride (g–C3N4)–based metal-free photocatalysts for water splitting: A review

Metal-organic frameworks (MOFs) have been attracted considerable attention in the field of energy generation and environmental remediation. In this article, a novel core–shell In2S3@MIL-125(Ti) (MLS) photocatalytic adsorbent was successfully prepared by a facile solvothermal method. The as-obtained materials were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, N2 adsorption–desorption isotherm, X-ray photoelectron spectroscopy, UV–vis diffuse reflection spectroscopy and zeta potentials. It is indicated that the hybrids consisted of MIL-125(Ti) as the core and three-dimensional In2S3 sheets network as the shell has high surface area, mesoporous structure, and improved electronegativity and visible-light absorption. The MLS exhibited excellent adsorption performance for the removal of tetracycline (TC) from water. The adsorption process is sensitive to the solution pH, ionic strength and initial TC concentration. The Langmuir isotherm and pseudo-second-order mode could well describe the adsorption process and adsorption kinetics. The adsorption mechanism is mainly responsible for surface complexation, π–π interactions, hydrogen bonding and electrostatic interactions. Further, in TC degradation experiments under visible light exposure in presence of core–shell MLS, the optimal additive content of MIL-125(Ti) in synthesis process was 0.1 g, and the corresponding photodegradation efficiency for TC was 63.3%, which was higher than that of pure In2S3 and pure MIL-125(Ti). The improved photocatalytic performance was mainly ascribed to the opened porous structure, effective transfer of photo-generated carriers, Ti3+–Ti4+ intervalence electron transfer and the synergistic effect between MIL-125(Ti) and In2S3. The degradation by-products of TC molecules were monitored by three-dimensional excitation-emission matrix fluorescence spectroscopy. Parts of TC molecules were mineralized into CO2 and H2O. The core–shell MLS composites also revealed good performance for the removal of TC from real wastewater including medical wastewater, municipal wastewater and river water. Therefore, the novel hybrids may be used as promising photocatalytic adsorbent for wastewater purification.

In situ synthesis of In2S3@MIL-125(Ti) core–shell microparticle for the removal of tetracycline from wastewater by integrated adsorption and visible-light-driven photocatalysis

An overview on limitations of TiO2-based particles for photocatalytic degradation of organic pollutants and the corresponding countermeasures

Nanoscale zero-valent iron/biochar composite as an activator for Fenton-like removal of sulfamethazine

Due to the emerging environmental issues related to heavy metals, concern about the soil quality of farming lands near manufacturing district is increasing. Investigating the function of soil microorganisms exposed to long-term heavy metal contamination is meaningful and important for agricultural soil utilization. This article studied the potential influence of several heavy metals on microbial biomass, activity, abundance, and community composition in arable soil near industrial estate in Zhuzhou, Hunan province, China. The results showed that soil organic contents (SOC) were significantly positive correlated with heavy metals, whereas dehydrogenase activity (DHA) was greatly depressed by the heavy metal stress. Negative correlation was found between heavy metals and basal soil respiration (BSR), and no correlation was found between heavy metals and microbial biomass content (MBC). The quantitative PCR (QPCR) and polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) analysis could suggest that heavy metal pollution has significantly decreased abundance of bacteria and fungi and also changed their community structure. The results could contribute to evaluate heavy metal pollution level in soil. By combining different environmental parameters, it would promote the better understanding of heavy metal effect on the size, structure, and activity of microbial community in arable soil.

Changzheng Fan

Papers

An overview on limitations of TiO2-based particles for photocatalytic degradation of organic pollutants and the corresponding countermeasures

Nanoscale zero-valent iron/biochar composite as an activator for Fenton-like removal of sulfamethazine

Response of rhizosphere microbial community structure and diversity to heavy metal co-pollution in arable soil

Continuous thermophilic composting (CTC) for rapid biodegradation and maturation of organic municipal solid waste.

Rapid startup of thermophilic anaerobic digester to remove tetracycline and sulfonamides resistance genes from sewage sludge