RESUMEN
Acid mine drainage (AMD) is an environmental issue linked with mining activities, causing the release of toxic water from mining areas. Polyethersulphone (PES) membranes are explored for AMD treatment, but their limited hydrophilicity hinders their performance. Chitosan enhances hydrophilicity, addressing this issue. However, the effectiveness depends on chitosan's degree of deacetylation (DD), determined during the deacetylation process for chitosan production. This study optimized the chitin deacetylation temperature, alkaline (NaOH) concentration, and reaction time, yielding the highest chitosan degree of deacetylation (DD) for PES/chitosan membrane applications. Prior research has shown that high DD chitosan enhances membrane antifouling and hydrophilicity, increasing contaminant rejection and permeate flux. Evaluation of the best deacetylation conditions in terms of temperature (80, 100, 120 °C), NaOH concentration (20, 40, 60 wt.%), and time (2, 4, 6 h) was performed. The highest chitosan DD obtained was 87.11% at 80 °C, 40 wt. %NaOH at 4 h of chitin deacetylation. The PES/0.75 chitosan membrane (87.11%DD) showed an increase in surface hydrophilicity (63.62° contact angle) as compared to the pristine PES membrane (72.83° contact angle). This was an indicated improvement in membrane performance. Thus, presumably leading to high contaminant rejection and permeate flux in the AMD treatment context, postulate to literature.
RESUMEN
This research evaluated using inorganic adsorbents for removal of metals from solution. Batch experiments were carried out to determine the effects of adsorbent dosage, initial metal concentration and agitation time on metal removal. The results showed increasing metal ion removal with increasing adsorbent dosage, metal concentration and agitation time. Removal efficiencies of Al3+ and Mn2+ were reported at above 99% and 98%. Kinetic studies showed that the three adsorbents data on both Al3+ and Mn2+ removal were pertaining to pseudo-first-order and second-order kinetics and had a good fit to Elovich indicating that the adsorption rate-limiting step could be inferred as chemical sorption.