Selection of a rural arsenic treatment system using multi-criteria decision-making techniques

In the last decade, arsenic contamination in water resources from natural and anthropogenic sources has become an important issue in Turkey. In particular, high arsenic levels have been detected in the groundwater of many small towns and villages in the Aegean Region and Central Anatolia. The implementation of appropriate treatment systems is essential to reduce the arsenic concentrations to acceptable levels. The ideal technology for rural areas should be effective in producing arsenic-free water but should also be low cost, have low energy demand and require little maintenance. Although technical and economic parameters play important roles in the selection of technology, it should also be environmentally friendly. As there are several important factors affecting decisions about treatment systems, in this study the analytical hierarchy process (AHP) method was used to solve the problem and determine the preferences. In the study, "chemical treatment", "adsorption", and "reverse osmosis" were chosen as alternatives. Treatment alternatives were evaluated considering technical, economic and environmental criteria. The results of the AHP analysis show that the operational features and treatment performance were the major influencing factors for rural settlements in decision-making. According to AHP, the best alternative was adsorption. The ranking order of the alternatives for rural settlements was adsorption > reverse osmosis > chemical treatment.