The availability of clean drinking water in rural areas, disaster zones and third world countries is a major concern. A number of purification methods are available but are often energy intensive and only feasible for highly populated areas. Simple and cheap decentralized water treatment systems can however be produced for isolated locations. Quartz particles have been modified via an inductively coupled radio frequency plasma reactor fitted with a rotating barrel chamber. Plasma polymerization was undertaken using allylamine as the monomer to produce amine terminated surfaces. Amine functionalisation produces surfaces with higher isoelectric points which become positively charged in solution, thus removing negatively charged contaminants via electrostatic attraction. Polymerization time, RF power and monomer flow were varied for optimal humic acid removal. The effect of these parameters on surface chemistry was determined using XPS and electrokinetic analysis.

The effectiveness of plasma polymerized allylamine coated quartz particles for water treatment was investigated via humic acid removal. Humic acid is a negatively charged contaminant and originates from the biodegradation of organic matter, producing undesirable colour and taste. The coated particles were immersed into solutions of varying humic acid concentrations with particle mass, pH and adsorption time varied. The mass of humic acid removed was determined via a UV-vis spectrophotometer at λ=254 nm. Plasma polymerization has shown to be a successful method for modifying quartz particles for water treatment. Further development of the plasma polymerization process and investigation of additional contaminants will aid in its development as a decentralized water treatment system.