Super capacity of ligand-engineered biochar for sorption of malachite green dye: key role of functional moieties and mesoporous structure.

This study synthesized a new thiomalic acid-modified rice husk biochar (TMA-BC) as a versatile and eco-friendly sorbent. After undergoing chemical treatments, the mercerized rice husk biochar (NaOH-BC) and TMA-BC samples showed higher BET surface area values of 277.1 m/g and 305.

Comprehensive metagenomic and enzyme activity analysis reveals the inhibitory effects and potential toxic mechanism of tetracycline on denitrification in groundwater.

The widespread use of tetracycline (TC) inevitably leads to its increasing emission into groundwater. However, the potential risks of TC to denitrification in groundwater remain unclear. In this study, the effects of TC on denitrification in groundwater were systematically investigated at both the protein and gene levels from the electron behavior aspect for the first time.

Degradation mechanism of Bisphenol S via hydrogen peroxide/persulfate activated by sulfidated nanoscale zero valent iron.

Fenton-like oxidation processes are widely used to degrade recalcitrant organic pollutants, but are limited by narrow application pH and low reaction efficiency. This study investigated the synchronous activation of HO and persulfate (PDS) by sulfidated zero valent iron (S-nZVI) in ambient conditions for Fenton-like oxidation of bisphenol S (BPS), an estrogenic endocrine-disrupting chemical. The activation of S-nZVI induced HO or PDS could be greatly enhanced with the assistance of PDS and HO, respectively, even across a wide range of pH value (3-11).

Biochar enhanced the stability and microbial metabolic activity of aerobic denitrification system under long-term oxytetracycline stress.

Reactors were established to study the feasibility of the direct addition of modified biochar to alleviate the long-term stress of oxytetracycline (OTC) on aerobic denitrification (AD) and improve the stability of the system. The results showed that OTC stimulated at μg/L, and inhibited at mg/L. The higher the concentration of OTC, the longer the system was affected.

Sulfamethoxazole degradation by alpha-MnO/periodate oxidative system: Role of MnO crystalline and reactive oxygen species.

Pollutant degradation via periodate ([Formula: see text]) and transitional metal oxides provides an economical, energy-efficient way for chemical oxidation process in environmental remediation. However, catalytic activation of periodate by manganese dioxide and the associated mechanism were barely investigated. In this study, four MnO polymorphs (α-, β-, γ- and δ-MnO) were synthesized and tested to activate [Formula: see text] for the degradation of sulfamethoxazole (SMX).

Insight into enrichment of anammox bacteria by a polyurethane sponge carrier coupled with iron-carbon micro-electrolysis under no strict anaerobic condition.

A novel composite carrier (ICME-PS) was formed by coupling polyurethane sponge carriers (PS) with different pore sizes (15, 25, 40 ppi) and iron-carbon micro-electrolysis (ICME), which was used for enrichment of anammox bacteria and stable operation under no strict anaerobic condition. An increase of 5.67%-38.

Microbially-mediated synthesis of activated carbon derived from cottonseed husks for enhanced sulfanilamide removal.

This study provided a novel pathway to develop activated carbon with enhanced adsorption performance via feedstock pretreatment by fungi. The growth of Pleurotus ostreatus on cottonseed husks offered this feedstock an advantageous pore size for porous carbon making. The prepared activated carbons derived from cottonseed husks (CSH-ACs) during different fungal growth periods exhibited extraordinary performance than commercial activated carbon for sulfanilamide adsorptive removal.

Application of electric fields to mitigate inhibition on anammox consortia under long-term tetracycline stress.

The feasibility of applying electric fields to mitigate inhibition of tetracycline (TC) on anammox process and improve system stability was evaluated in this study. Three electric field intensities of 1, 3 and a variable intensity of 1-6 V (VEF) were used to optimize electric field intensity under gradually increasing addition of TC (0.5, 2 and 10 mg L).

Hazardous Heavy Metals Accumulation and Health Risk Assessment of Different Vegetable Species in Contaminated Soils from a Typical Mining City, Central China.

Heavy metal poisoning has caused serious and widespread human tragedies via the food chain. To alleviate heavy metal pollution, particular attention should be paid to low accumulating vegetables and crops. In this study, the concentrations of five hazardous heavy metals (HMs), including copper (Cu), chromium (Cr), lead (Pb), cadmium (Cd), and arsenic (As) were determined from soils, vegetables, and crops near four typical mining and smelting zones.

Evolution of Singlet Oxygen by Activating Peroxydisulfate and Peroxymonosulfate: A Review.

Advanced oxidation processes (AOPs) based on peroxydisulfate (PDS) or peroxymonosulfate (PMS) activation have attracted much research attention in the last decade for the degradation of recalcitrant organic contaminants. Sulfate (SO) and hydroxyl (OH) radicals are most frequently generated from catalytic PDS/PMS decomposition by thermal, base, irradiation, transition metals and carbon materials. In addition, increasingly more recent studies have reported the involvement of singlet oxygen (O) during PDS/PMS-based AOPs.

Biotransformation of doxycycline by Brevundimonas naejangsanensis and Sphingobacterium mizutaii strains.

The fate of doxycycline (DC), a second generation tetracycline antibiotic, in the environment has drawn increasing attention in recent years due to its wide usage. Little is known about the biodegradability of DC in the environment. The objective of this study was to characterize the biotransformation of DC by pure bacterial strains with respect to reaction kinetics under different environmental conditions and biotransformation products.

Health Risk Assessment of Heavy Metals Accumulated on PM Fractioned Road Dust from Two Cities of Pakistan.

The aim of this study is to identify and investigate levels of toxic heavy metals in PM fractioned road dust to better understand the associated inhalation risk and potential health impacts. To achieve this aim, concentrations of seven traffic generated heavy metals (Cu, Pb, Zn, Cd, Ni, Sb, and Cr) were determined in the PM fraction of road dust samples from four different locations (offices, residential, hospital, and school) in two cities (Karachi and Shikarpur) of Pakistan using ICP-MS. The average concentration values of heavy metals in Karachi were as follows: 332.

[Enhanced Chromate (Ⅵ) Removal Characteristics and Mechanism Using Graphene Oxide Immobilized Nanoscale Zero-Valent Iron Coupled with a Weak Magnetic Field (GO-nFe/WMF)].

A green, high-efficiency mesoporous magnetic material with strong reusability and oxidation resistance, named graphene oxide immobilized nanoscale zero-valent iron (GO-nFe), was prepared by a co-precipitation method. The structure, appearance, surface elements, and valence of GO-nFe were characterized via FESEM, TEM, FTIR, BET, XRD, and XPS. The characteristics and mechanism of Cr(Ⅵ) treatment in water using a weak magnetic field (WMF) coupled with GO-nFe (GO-nFe/WMF) were studied.

Transformation mechanisms of tetracycline by horseradish peroxidase with/without redox mediator ABTS for variable water chemistry.

The threat of antibiotics in the environment causing antibiotics resistance is a global health concern. Enzymes catalyze pollutant transformations, and how commercially available enzymes like horseradish peroxidase (HRP), with or without a redox mediator, may be used to degrade antibiotics in water treatment is of great interest. This work demonstrates tetracycline transformation by HRP, and how it is significantly enhanced by free radicals created from the mediator 2,2-Azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS).

Application of biochar in advanced oxidation processes: supportive, adsorptive, and catalytic role.

The advanced oxidation processes (AOPs), especially sulphate radical (SO)-based AOPs (SR-AOPs), have been considered more effective, selective, and prominent technologies for the removal of highly toxic emerging contaminants (ECs) due to wide operational pH range and relatively higher oxidation potential (2.5-3.1 V).

Characterization of the copper resistance mechanism and bioremediation potential of an Acinetobacter calcoaceticus strain isolated from copper mine sludge.

Bioremediation is one of the most effective ways for removal of heavy metals and restoration of contaminated sites. This study investigated the copper (Cu) resistance mechanism and bioremediation potential of an Acinetobacter calcoaceticus strain KW3 isolated from sludge of Cu mine. The effect of Cu concentrations on the bacterial growth, biomass, and adsorption capacity, as well as the effect of contact time on the adsorption process was evaluated in a batch biosorption test.

Synergistic degradation of PNP coupling HO with persulfate catalyzed by nano zero valent iron.

HO and persulfate (PDS) activated by iron are attracting much attention due to their strong oxidation capacity for the effective degradation of organic pollutants. However, they face problems such as requiring an acidic reaction pH and difficulty of Fe regeneration. In this study, the simultaneous activation of HO and persulfate by nanoscaled zero valent iron (nZVI) was investigated for the degradation of -nitrophenol (PNP).

Adsorption-assisted decontamination of Hg(ii) from aqueous solution by multi-functionalized corncob-derived biochar.

Mercury (Hg) contamination of wastewater streams as a result of anthropogenic activities is a great threat to living organisms due to its acute toxicity. Therefore, current research is focused on the development of effective remediation technologies to protect human health and the environment. In this study, a novel chemical modification route was applied for the multi-functionalization of biochar in order to make it more efficient and selective for Hg(ii) removal from aqueous solution.

[Degradation Mechanism of Tetracycline Using Fe/Cu Oxides as Heterogeneous Activators of Peroxymonosulfate].

A green, highly efficient, and porous copper-ferrite heterogeneous catalyst (Fe-Cu-400) with good magnetism was synthesized via a coprecipitation method. The catalysts were characterized using XRD, BET, FESEM, and EDS. The performance of Fe-Cu-400 as a catalyst was evaluated by activating peroxymonosulfate (PMS) for degradation of tetracycline (TC) in aqueous solution and investigating the influence of several water parameters.

Background Nutrients Affect the Biotransformation of Tetracycline by Stenotrophomonas maltophilia as Revealed by Genomics and Proteomics.

Certain bacteria are resistant to antibiotics and can even transform antibiotics in the environment. It is unclear how the molecular mechanisms underlying the resistance and biotransformation processes vary under different environmental conditions. The objective of this study is to investigate the molecular mechanisms of tetracycline resistance and biotransformation by Stenotrophomonas maltophilia strain DT1 under various background nutrient conditions.

Efficient activation of peroxymonosulfate by magnetic Mn-MGO for degradation of bisphenol A.

A heterogeneous manganese/magnetite/graphene oxide (Mn-MGO) hybrid catalyst was fabricated through the reduction of KMnO by ethylene glycol in the presence of magnetite/GO (MGO) particles. The Mn-MGO catalyst exhibited high efficacy and long-term stability in activating peroxymonosulfate (PMS) to generate sulfate radicals for the removal of bisphenol A (BPA) from water. The results of the batch experiments indicated that an increase in the catalyst dose and solution pH could enhance BPA degradation in the coupled Mn-MGO/PMS system.

Biotransformation of tetracycline by a novel bacterial strain Stenotrophomonas maltophilia DT1.

Although several abiotic processes have been reported that can transform antibiotics, little is known about whether and how microbiological processes may degrade antibiotics in the environment. This work isolated one tetracycline degrading bacterial strain, Stenotrophomonas maltophilia strain DT1, and characterized the biotransformation of tetracycline by DT1 under various environmental conditions. The biotransformation rate was the highest when the initial pH was 9 and the reaction temperature was at 30°C, and can be described using the Michaelis-Menten model under different initial tetracycline concentrations.

Reductive sequestration of chromate by hierarchical FeS@Fe(0) particles.

Nanoscale Fe(0) (nFe(0)) can detoxify Cr(VI)-bearing wastewater and groundwater, but rapid passivation is a negative factor for large-scale remediation applications. In this study, a magnetic FeS@Fe(0) hybrid material was fabricated by immobilization of iron sulfide (FeS) onto Fe(0) particles to improve the Cr(VI) removal capacity. The solid characterization confirmed that Fe(0) particles were encapsulated by amorphous iron monosulfide.

Phytoremediation of heavy metal contaminated soil potential by woody plants on Tonglushan ancient copper spoil heap in China.

Fast-growing metal-accumulating woody plants are considered potential candidates for phytoremediation of metals. Tonglushan mining, one of the biggest Cu production bases in China, presents an important source of the pollution of environment. The sample was collected at Tonglushan ancient copper spoil heap.