Synthesis and characterisation of some new non-conventional materials as low-cost adsorbents for removal of nitrates from groundwater in Al-Qurayyat city northern Saudi Arabia

Abstract

Groundwater in Saudi Arabia contains high concentrations of nitrates. Nitrates are respected as the main groundwater pollutant causing dangerous health and environmental influences. The removal of nitrate from groundwater in Al-Qurayyat, Saudi Arabia, was investigated in this work using palm wastes. Palm fibers (PFI) and palm fronds (PFR) were initially employed as feedstock for the manufacturing of adsorbents, which were activated by heating to 300 °C. The activation of PFI and PFR resulted in an increase in surface area. Batch tests were used to determine the best environment for nitrate adsorption on PFI and PFR. The best factors for nitrate removal were as follows: the contact time was 20 min, the initial concentration of NO3- was 20 mg/L, the dose was 2 g/L and the pH was 6. The adsorption capacity of the PFI and PFR was 72% to 77%. In terms of nitrate removal effectiveness under local optimal circumstances, comparisons with commercial activated carbon (CAC) and anion exchange resin (Purolite A 520E) revealed that PFI and PFR are inferior to CAC and Purolite A 520E. However, the PFI and PFR were able to remove nitrate economically even under the most basic operating parameters.

Keywords

• water pollution
• agricultural wastes
• fronds
• palm fibers