Mechanochemical Synthesis of Cross-Linked Chitosan and Its Application as Adsorbent for Removal of Per- and Polyfluoroalkyl Substances from Simulated Electroplating Wastewater.

Chitosan is a promising adsorbent for removing a wide range of pollutants from wastewater. However, its practical application is hindered by instability in acidic environments, which significantly impairs its adsorption capacity and limits its utilization in water purification. While cross-linking can enhance the acid stability of chitosan, current solvent-based methods are often costly and environmentally unfriendly.

Regeneration of exhausted adsorbents after PFAS adsorption: A critical review.

The adsorption process efficiently removes per- and polyfluoroalkyl substances (PFAS) from water, but managing exhausted adsorbents presents notable environmental and economic challenges. Conventional disposal methods, such as incineration, may reintroduce PFAS into the environment. Therefore, advanced regeneration techniques are imperative to prevent leaching during disposal and enhance sustainability and cost-effectiveness.

Emerging contaminants in the northwest area of the Tai Lake Basin, China: Spatial autocorrelation analysis for source apportionment and wastewater-based epidemiological analysis.

In the present study, 60 emerging contaminants (ECs) were detected from 88 target compounds in the district of Wujin, which is the northwest area of Tai Lake Basin, China. Among them, CF (caffeine), a type of PhAC (pharmaceutically active compound), was detected as the pollutant with the highest concentration. It was observed that the removal efficiencies of PFASs (per-/polyfluoroalkyl substances) in wastewater treatment plants were lower than those of pesticides; further, those of pesticides were lower than those of PhACs.

Mechanochemically sulfidated zero-valent iron as persulfate activation catalyst in permeable reactive barriers for groundwater remediation - A feasibility study.

The technology of permeable reactive barriers is reliable and economically effective to prevent the spread of pollutants in groundwaters. Yet, it is efficacious only with easily reducible chemicals such as heavy metals and halogenated organics. In the present study, sulfidated zero-valent iron solventless synthesized by ball-milling is proposed as a possible barrier filling for activation of persulfate to achieve sound removal of reduction-resistant organic pollutants (the herbicide atrazine was used as a model pollutant).

Wastewater surveillance for 168 pharmaceuticals and metabolites in a WWTP: Occurrence, temporal variations and feasibility of metabolic biomarkers for intake estimation.

Wastewater-based epidemiology (WBE) is amply used for mining information about public health such as the estimation of consumption/intake of certain substances. Yet, proper biomarker selection is critical to obtain reliable data. This study measured a broad range of pharmaceuticals and metabolites in a wastewater treatment plant in Beijing, China, and evaluated their suitability as consumption estimation biomarkers.

Mechanochemical synthesis of catalysts and reagents for water decontamination: Recent advances and perspective.

This paper aims to provide insights on mechanochemistry as a green and versatile tool to synthesize advanced materials for water remediation. In particular, mechanochemical methodologies for preparation of reagents and catalysts for the removal of organic pollutants are reviewed and discussed, focusing on those materials that, directly or indirectly, induce redox reactions in the contaminants (i.e.

Improved fractal kinetic model to predict mechanochemical destruction rate of organic pollutants.

Mechanochemical destruction of organic pollutants by high energy milling with inorganic reagents is considered a promising non-thermal technology to detoxify hazardous waste. However, due to complex nature of the physicochemical phenomena involved, pollutant destruction kinetics heavily depends on the used reagents and operating parameters, thus varying case by case. In the present work, a fractal model was validated as flexible tool to interpolate pollutant mechanochemical destruction data satisfactorily.

Role of hydrogenated moiety in redox treatability of 6:2 fluorotelomer sulfonic acid in chrome mist suppressant solution.

6:2 Fluorotelomer sulfonic acid (6:2 FTS) is used as alternative to perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) for different purposes such as chrome mist suppressant (CMS) and active ingredient in fire-fighting foams. In this study, degradability of 6:2 FTS under ultraviolet/persulfate (UV/PS) and ultraviolet/sulfite (UV/SF), which are typical technologies for advanced oxidation and reduction, were investigated respectively. Due to the hydrogenated moiety, 6:2 FTS was decomposed completely by UV/PS within 10 min, forming a mixture of short-chain perfluoroalkyl carboxylic acids with variable chain length (2-7 carbon atoms).

Occurrence and variations of pharmaceuticals and personal-care products in rural water bodies: A case study of the Taige Canal (2018-2019).

A systematic monitoring campaign of pharmaceuticals and personal-care products (PPCPs) was performed in the Taige Canal basin, which is located in a rural area of the Yangtze River Delta. A total of 55 out of 61 monitored PPCPs were detected, with concentrations up to 647 ng/L. The maximum concentrations of 75% of monitored antibiotics and 80% of non-antibiotics were above the median values of previously reported maximum concentrations in China, indicating that the basin is heavily contaminated.

Mechanochemical degradation of perfluorohexane sulfonate: Synergistic effect of ferrate(VI) and zero-valent iron.

Perfluorohexane sulfonate (PFHxS) has been newly recommended to be added into the Stockholm Convention on persistent organic pollutants (POPs). As one of the major perfluoroalkyl pollutants, its long half-time in human serum and neurotoxicity are cause for significant concern. Although mechanochemical degradation has been evaluated as a promising ecofriendly technology to treat pollutants, the extraordinary stability of poly- and perfluoroalkyl substances (PFASs) raises harsh requirements for co-milling reagents.

Characteristics of pharmaceutically active compounds in surface water in Beijing, China: Occurrence, spatial distribution and biennial variation from 2013 to 2017.

Pharmaceutically active compounds (PhACs) are widely found in the environment due to vast human consumption. Lots of work has been devoted to investigating the occurrence and seasonal variations globally. To fully understand characteristics and cross-year variation of PhACs in Beijing, 35 PhACs were analyzed in 46 sites across Beijing from both urban and suburban areas.

Effect of high energy ball milling on organic pollutant adsorption properties of chitosan.

In the present work, chitosan physicochemical transformations that occur during high energy ball milling are investigated and correlated with adsorption capacity of organic pollutants (using azo-dye reactive red 2 as molecular probe). Experimental results reveal that chitosan ball milled for 1 h shows a 70% increase of adsorption capacity, compared to unmilled one, while longer milling time causes a sensible reduction of such capacity. This trend correlates with specific surface area evolution under milling, thus suggesting the primary role of particle comminution in augmenting chitosan adsorption properties.

Ultrasound-Assisted Preparation of Chitosan/Nano-Activated Carbon Composite Beads Aminated with (3-Aminopropyl)Triethoxysilane for Adsorption of Acetaminophen from Aqueous Solutions.

A composite chitosan/nano-activated carbon (CS-NAC) aminated by (3-aminopropyl)triethoxysilane (APTES) was prepared in the form of beads and applied for the removal of acetaminophen from aqueous solutions. NAC and APTES concentrations were optimized to obtain a suitable adsorbent structure for enhanced removal of the pharmaceutical. The aminated adsorbent (CS-NAC-APTES beads) prepared with 40% / NAC and 2% / APTES showed higher adsorption capacity (407.

Cross-linked chitosan/zeolite as a fixed-bed column for organic micropollutants removal from aqueous solution, optimization with RSM and artificial neural network.

Organic micropollutants (MPs) in low concentrations can affect aquatic ecosystems and human health. Adsorption technique is one of the promising methods to remove MPs. Chitosan and zeolites are environmentally friendly and low-cost adsorbents.

Removal of F-53B as PFOS alternative in chrome plating wastewater by UV/Sulfite reduction.

Chrome mist suppressants are key chemicals used in the chrome plating industry to reduce exposure of workers by inhalation to airborne chromic acid pollution. Perfluoroalkyl sulfonated compounds are excellent mist suppressants, thanks to their chemical stability and surface activity. Therefore, despite mounting evidence for their persistence, bioaccumulation and toxicity, it is likely that such chemicals will continue to be used for the foreseeable future because of their importance and lack of alternatives.

Synthesis and Regeneration of A MXene-Based Pollutant Adsorbent by Mechanochemical Methods.

In the present study, an adsorbent material for removal of organic contaminants in wastewater is synthetized by a green and facile mechanochemical method. It is composed of TiCT MXene layers (obtained by mechanochemical etching of MAX phase with concentrated HF) pillared with terephthalate by rapid direct reaction. Such material shows high specific surface area (135.

Wastewater-based epidemiology in Beijing, China: Prevalence of antibiotic use in flu season and association of pharmaceuticals and personal care products with socioeconomic characteristics.

Wastewater-based epidemiology is an emerging field that has mostly been applied to investigate consumption of illicit drugs. In this study, the wastewater-based epidemiology approach was employed to study consumption of pharmaceuticals and personal care products (PPCPs) and measure their prevalence of use in eight densely populated, urban areas of Beijing, China. Ammonium loads were used to estimate the population equivalents of each sewershed.

Degradation of Ofloxacin by Perylene Diimide Supramolecular Nanofiber Sunlight-Driven Photocatalysis.

This study describes a promising sunlight-driven photocatalyst for the treatment of ofloxacin and other fluoroquinolone antibiotics in water and wastewater. Perylene diimide (PDI) supramolecular nanofibers, which absorb a broad spectrum of sunlight, were prepared via a facile acidification polymerization protocol. Under natural sunlight, the PDI photocatalysts achieved rapid treatment of fluoroquinolone antibiotics, including ciprofloxacin, enrofloxacin, norfloxacin, and ofloxacin.

Degradation of PFOA Substitute: GenX (HFPO-DA Ammonium Salt): Oxidation with UV/Persulfate or Reduction with UV/Sulfite?

Hexafluoropropylene oxide dimer acid (HFPO-DA, ammonium salt with trade name: GenX) has been recently detected in river water worldwide. There are significant concerns about its persistence, and potential adverse effects to the biota. In this study, the degradability of GenX by typical advanced redox technologies (UV/persulfate and UV/sulfate) is investigated.

Mechanochemical enhancement of the natural attenuation capacity of soils using two organophosphate biocides as models.

Mechanochemical treatment by high energy ball milling is a promising technology to safely destroy organic pollutants in contaminated soil and allow its possible beneficial reuse. The present study investigates the mechanochemical activation of four major soil components, which induces generation of electrons on particle surfaces. Such phenomenon is demonstrated to occur on oxides by formation of trapped electrons in oxygen vacancies (following a zeroth-order kinetics), as well as on quartz and clayey materials to form fresh electron-rich surfaces by homolytic bond rapture (according to a first-order kinetics).

Typical pharmaceuticals in major WWTPs in Beijing, China: Occurrence, load pattern and calculation reliability.

Pharmaceutically active compounds (PhACs) are recognized as one of the most serious emerging micropollutants. Wastewater treatment plants are the major way through which such contaminants enter the environment. Therefore, an appropriate management of PhACs in these facilities can reduce their release into the environment.

Correction to: Formation of brominated and chlorinated dioxins and its prevention during a pilot test of mechanochemical treatment of PCB and PBDE contaminated soil.

The destruction of persistent organic pollutants(POPs) is a large challenge in particular in developing and emerging economies.

Mechanochemical pre-treatment for viable recycling of plastic waste containing haloorganics.

Chemical recycling technologies are the most promising for a waste-to-energy/material recovery of plastic waste. However, 30% of such waste cannot be treated in this way due to the presence of halogenated organic compounds, which are often utilized as flame retardants. In fact, high quantities of hydrogen halides and dioxin would form.

Mechanochemical mineralization of "very persistent" fluorocarbon surfactants ‒ 6:2 fluorotelomer sulfonate (6:2FTS) as an example.

Fluorinated organic chemicals have a wide variety of industrial and consumer applications. For long time perfluorooctane sulfonate and perfluorooctanoic acid have been used as precursors for manufacture of such chemicals. However, these C chain compounds have been demonstrated to be toxic, persistent, and bioaccumulative, thus inducing their phase-out.

Formation of brominated and chlorinated dioxins and its prevention during a pilot test of mechanochemical treatment of PCB and PBDE contaminated soil.

The destruction of persistent organic pollutants (POPs) is a large challenge in particular in developing and emerging economies. To date, a detailed assessment of non-combustion technologies with respect to formation of dioxins is lacking. In this study, an assessment of mechanochemical (MC) destruction technology for polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in contaminated soil remediation was conducted.