Several perfluoroalkyl and polyfluoroalkyl substances (PFASs) have been identified as chemicals of concern in the environment due to their persistence, global ubiquity, and classification as reproductive and developmental toxicants, endocrine disrupters, and possible carcinogens. Multiple PFASs are often found together in the environment due to product manufacturing methods and abiotic and biotic transformations. Treatment methods are needed to effectively sequester or destroy a variety of PFASs from groundwater, drinking water, and wastewater. This review presents a comprehensive summary of several categories of treatment approaches: (1) sorption using activated carbon, ion exchange, or other sorbents, (2) advanced oxidation processes, including electrochemical oxidation, photolysis, and photocatalysis, (3) advanced reduction processes using aqueous iodide or dithionite and sulfite, (4) thermal and nonthermal destruction, including incineration, sonochemical degradation, sub- or supercritical tr...

Degradation and Removal Methods for Perfluoroalkyl and Polyfluoroalkyl Substances in Water

Efficient decomposition of perfluorocarboxylic acids in aqueous solution using microwave-induced persulfate.

Additive manufacturing (AM) has gained significant attention due to its ability to drive technological development as a sustainable, flexible, and customizable manufacturing scheme. Among the various AM techniques, direct ink writing (DIW) has emerged as the most versatile 3D printing technique for the broadest range of materials. DIW allows printing of practically any material, as long as the precursor ink can be engineered to demonstrate appropriate rheological behavior. This technique acts as a unique pathway to introduce design freedom, multifunctionality, and stability simultaneously into its printed structures. Here, a comprehensive review of DIW of complex 3D structures from various materials, including polymers, ceramics, glass, cement, graphene, metals, and their combinations through multimaterial printing is presented. The review begins with an overview of the fundamentals of ink rheology, followed by an in‐depth discussion of the various methods to tailor the ink for DIW of different classes of materials. Then, the diverse applications of DIW ranging from electronics to food to biomedical industries are discussed. Finally, the current challenges and limitations of this technique are highlighted, followed by its prospects as a guideline toward possible futuristic innovations.

Direct Ink Writing: A 3D Printing Technology for Diverse Materials

A method of preparing preferred abrasive grain includes: preparing a dispersion including alpha alumina oxide monohydrate and zirconia sol therein; converting the dispersion to base grit material; and sintering the base grit to form abrasive grains. The presence of the zirconia sol within the dispersion from which the base grits are formed provides an improved abrasive grain. The improved abrasive grains are useful in abrasive products.

Abrasive grain containing alumina and zirconia.

Persulfate-based degradation of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) in aqueous solution: Review on influences, mechanisms and prospective

Ceramic oxide diphasic xerogels of structurally dissimilar phases (crystalline and amorphous, semicrystalline or noncrystalline) but compositionally similar phases will be converted to crystalline ceramic oxide products having enhanced densification when subjected to substantially lower sintering temperature.

Method of preparing ceramic compositions at lower sintering temperatures

Microwave–hydrothermal decomposition of chlorinated organic compounds

Compositionally triphasic nanocomposite gel is made by mixing two or more sols of ceramic precursor oxides. Such gel is then dried and ground to a fine powder which is pressed into compact bodies. The compact bodies are thereafter fired in a sintering oven at from 1100° C. to 1400° C. and, aided by the heat of reaction of the two or more nono gel powders, the (heterogeneous) mixture of such powders crystallizes into a homogeneous crystalline ceramic of α-cordierite at up to 100% of theoretical density. Thus, novel method of manufacture and novel ceramic end-product are provided.

Highly dense cordierite and method of manufacturing same

Mineralogy and thermal behavior of phosphates; I. Magnesium pyrophosphate

Cesium can be selectively recovered from a nuclear waste solution containing cesium together with other metal ions by contact with a modified phlogopite which is a hydrated, sodium phlogopite mica. Once the cesium has entered the modified phlogopite it is fixed and can be safely stored for long periods of time.

Rustum Roy

Papers

Method of preparing ceramic compositions at lower sintering temperatures

Microwave–hydrothermal decomposition of chlorinated organic compounds

Highly dense cordierite and method of manufacturing same

Mineralogy and thermal behavior of phosphates; I. Magnesium pyrophosphate

Process for cesium decontamination and immobilization