Reusable Water and Mineral Recovery from Acid Mine Water Drainage Treatment Through Integration of Adsorption and Antifouling Membranes processes

Abstract

Exponential growth in world population has led to the scarcity of natural resources. The most affected one is drinking water out of these natural resources. This chain reaction has produced adverse effects by fouling our natural resources of water. Due to the exponential growth of industries, concentration of heavy metals has increased. This situation can be addressed by introducing nanoparticles in the sample water that can remove hazardous contaminants from water such as viruses, metals, and nitrates. Various traditional and non-conventional methods have been in use such as reverse osmosis, nano-filtration, disinfection, using absorbents such as metals, micro-organisms, and dyes to obtain clean drinking water. This research focusses on this issue by adopting antifouling nanofiltration Polyethersulfone (PES) membrane using phase inversion methodology using Activated Carbon (AC) and Chitosan as main composites and individual fillers on the membrane matrix acting on acid mine drainage water. We have embedded nanoparticles and polymeric composites in the membrane matrix. The yield of this research is to enhance the antifouling behavior as well as flux and salt rejection. These membranes were embedded with concentrated PES, PES with 0.75% chitosan and 0.25% AC, 1.25% chitosan and 0.75% AC and 1.75% chitosan with 1.25 % Activated Carbon. To achieve high efficacy of the adopted methodology, diverse characterization techniques have been opted explicitly Scanning Electron Microscope (SEM), Fourier Transform Infrared (FTIR) spectroscopy, Antibacterial analysis, contact angle measurement, salt rejection, water retention, flux measurement, and mechanical testing. A comprehensive comparison of the acid mine water has been presented in this aspect. The results have clearly indicated an increase in the amount of porosity channels of the membranes having chitosan/AC as composites that explicitly demonstrates higher permeability. The results indicated an increase in water flux from ±4.56 mL.cm-2.h-1 to ±17.5 mL.cm-2.h-1. This rush in the values and decrease in contact angle ±66° to ±50° values clearly demonstrate that membranes became hydrophilic in character. Similarly, removal capacity for phosphate (99.99%) nitrate (99.80%) and ammonia (66.5%) contaminants were yielded. Tensile strength for PES membranes embedded AC and chitosan showed 4 times more strength as well. Bacteriostatic rate for E. coli and S. aureus bacteria has increased from 52.63 to 90.67.