Recent advances in strontium ion removal from wastewater

• MOFs and nanomaterials enhance the adsorption capacity of Sr²⁺. • Sr²⁺ biosorption is achieved by biosorbents in an environmentally benign process. • Hybrid systems combine adsorption of Sr²⁺ and filtration for enhanced efficiency. • Challenges, limitations, and future directions have been presented in detail. This review discusses current developments in strontium ion removal technologies from contaminated wastewater, focusing on new materials and methodologies for treatments of concern to the environment and health. Strontium, in particular its radioactive isotope, namely strontium-90 ( 90 Sr), represents one of the dangerous pollutants that call for effective remediation. The salient features of this advancement mainly deal with improved adsorbents consisting of MOFs (metal-organic frameworks), carbon-based nanomaterials , and biosorbents, which enhanced the uptake of strontium by high surface area and selectivity. Efforts are also being extended towards optimization for ion-exchange resins for higher efficiency coupled with reusability. The membrane filtration techniques involving nanofiltration and reverse osmosis yielded promising results, although membrane fouling remained a problem. Environmentally friendly, low-cost adsorbents from natural materials support sustainable water treatment. These are realized when scalability, cost-efficiency, and long-term performance challenges remain open; they thus are a worrisome element to call for further research and innovation.