Characterization of uranium and its progenies in drinking water and assessment of dose to public around a NHBRA, Odisha, India

234U/238U disequilibrium and 235U/238U ratios measured using MC-ICP-MS in natural high background radiation area soils to understand the fate of uranium

The Chhatrapur-Gopalpur coastal area in Odisha, India is a well-known natural high background radiation (HBRA) area due to the abundance of monazite (a thorium bearing radioactive mineral) in beach sands and soils. Recent studies on Chhatrapur-Gopalpur HBRA groundwater have reported high concentrations of uranium and its decay products. Therefore, the soils of the Chhatrapur-Gopalpur HBRA are reasonably suspected as the sources of these high uranium concentrations in groundwater. In this report, first the uranium concentrations in soil samples were measured using inductively coupled plasma mass spectrometry (ICP-MS) and they were found to range from 0.61 ± 0.01 to 38.59 ± 0.16 mg kg^-１. Next, the ²³⁴U/²³⁸U and ²³⁵U/²³⁸U isotope ratios were measured to establish a baseline for the first time in Chhatrapur-Gopalpur HBRA soil. Multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) was used for measurement of these isotope ratios. The ²³⁵U/²³⁸U ratio was observed to be the normal terrestrial value. The ²³⁴U/²³⁸U activity ratio, was calculated to understand the secular equilibrium between ²³⁴U and ²³⁸U in soil and it varied from 0.959 to 1.070. To understand the dynamics of uranium in HBRA soil, physico-chemical characteristics of soil were correlated with uranium isotope ratios and this correlation of ²³⁴U/²³⁸U activity ratio indicated the leaching of ²³⁴U from Odisha HBRA soil.

A decade of exploring MXenes as aquatic cleaners: Covering a broad range of contaminants, current challenges and future trends

Clean water, the elixir of life, is of tremendous importance in achieving environmental sustainability and the balanced functioning of our ecosystem. Coupled with population growth, several anthropogenic activities and environmental catastrophes have together contributed to an alarming increase in the concentration of toxic pollutants in water bodies. Diversified physiochemical conditions of water matrices, ranging from mining drainage to seawater, is the critical challenge in designing adsorbents. MXenes, a new class of 2D layered materials, are transition metal nitrides, carbides, carbonitrides or borides formed through selective etching process. MXenes are known to have high surface area and activity with biological compatibility and chemical stability and therefore are promising adsorbents and have been explored for a broad range of contaminants. This review starts with a brief about environmental contaminants followed by synthesis and modifications of MXenes. It then revolves around their so far explored adsorbing and degradation properties for different contaminants ranging from toxic metals, inorganic ions, and radionuclides to various organic pollutants, including dyes, pharmaceuticals, aromatic hydrocarbons, and pesticides, etc. Finally, we have discussed associated toxicity, secondary contamination, future trends, and challenges in ascertaining scalability and wide-range applicability of MXenes in natural environmental conditions to make them a warrior of water sustainability.