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Acid mine drainage (AMD), an acidic effluent characterized by high concentrations of sulfate and heavy metals, is an environmental and economic concern. The performance of an integrated submerged direct contact membrane distillation (DCMD)zeolite sorption system for AMD treatment was evaluated. The results showed that modified (heat treated) zeolite achieved 26-30% higher removal of heavy metals compared to natural untreated zeolite.Heavy metal sorption by heat treated zeolite followed the order of Fe>Al>Zn>Cu>Ni and the data fitted well to Langmuir and pseudo second order kinetics model. Slight pH adjustment from 2 to 4 significantly increased Fe and Al removal rate (close to 100%) due to a combination of sorption and partial precipitation. An integrated system of submerged DCMD with zeolite for AMD treatment enabled to achieve 50% water recovery in 30 h. The integrated system provided a favourable condition for zeolite to be used in powder form with full contact time in a storing tank. Likewise, heavy metal removal from AMD by zeolite, specifically Fe and Al, mitigated membrane fouling on the surface of the hollow fiber *Manuscript (double-spaced and continuously LINE and PAGE numbered) Click here to view linked References submerged membrane. The integrated system produced high quality fresh water while concentrating sulfuric acid and valuable heavy metals (Cu, Zn and Ni).

Rare earth elements (REEs) have become a strategic resource extensively used in renewable energy technologies and modern electronic devices. Depletion of natural REE-bearing mineral deposits has made selective recovery of REEs from alternative sources crucial in meeting the rising global demand. A chromium-based metal−organic framework was synthesized and modified with N-(phosphonomethyl)iminodiacetic acid (PMIDA) in this study to selectively recover REEs (europium, Eu) from chemically complex zinc ore leachate. The adsorbent was characterized and comprehensively examined for Eu uptake as a function of adsorbate concentration, contact time, and pH of the solution. Cr-MIL-PMIDA showed a maximum adsorption capacity of 69.14 mg/g at pH 5.5 while adsorption kinetics best fitted the pseudo-second-order model. Furthermore, Cr-MIL-PMIDA showed exceptional selectivity (88%) toward Eu over competing transitional metal ions (Na, Mg, Al, Ca, Mn, Fe, Ni, Cu, Co, and Zn) found in the dissolved mine ore. High selectivity toward REEs was attributed to the formation of coordinative complexes with grafted carboxylate, phosphonic, and residual amine functional groups. Cr-MIL-PMIDA demonstrated excellent structural stability over multiple regeneration cycles, highlighting its potential for industrial application for REE recovery.