Use of natural, modified, and expanded perlite for cation removal in water samples from Bursa and analysis by ion chromatography method

Water is the fundamental resource for sustaining life and plays a critical role in maintaining ecosystem balance, economic development, and human health. However, increasing industrial activities, agricultural production, and population pressure have intensified cation pollution in both surface and groundwater. In this study, drinking and domestic water samples collected from various locations in Bursa, Türkiye, were analyzed to investigate the removal potential of major cations (Na⁺, K⁺, Ca²⁺, Mg²⁺, and NH₄⁺). As adsorbents, natural raw perlite, expanded perlite, and chitosan-modified perlite were employed. For each sample, 1 g, 5 g, and 10 g of adsorbent were added to 100 mL of water, and adsorption experiments were conducted at contact times of 1, 8, and 24 hours. Cation analyses were performed using a Metrohm 882 Compact IC Plus ion chromatography device in accordance with the TS EN ISO 14911 standard. According to the experimental results, the NH₄⁺ ion was almost completely removed by all types of perlite. The raw perlite showed a high level of efficiency in the removal of K⁺ and Mg²⁺ ions, while the removal of Ca²⁺ ions generally remained at a moderate level. The removal of Na⁺ ions was low for all adsorbents, and negative removal was observed under certain conditions. Expanded perlite achieved partial success for some ions, whereas modified perlite showed limited or negative removal performance in most cases. In conclusion, perlite-based adsorbents have shown applicability in the removal of cation pollution in Bursa waters, particularly for NH₄⁺, K⁺, Ca²⁺, and Mg²⁺ ions. Considering Turkey's rich perlite reserves, this natural and environmentally friendly material can be evaluated as a low-cost and domestic adsorbent alternative for the treatment of drinking, domestic, and irrigation waters. The widespread use of perlite as a sustainable treatment method would not only reduce dependency on imported chemical treatment materials but also increase the economic value of local resources. Moreover, the use of such natural materials prevents possible secondary environmental damages and represents an eco-friendly approach. Future studies should focus on testing the performance of perlite in different water matrices through large-scale pilot applications, which will be of great importance for the widespread implementation of this technology. In this way, both drinking water quality can be improved and salinity problems in agricultural irrigation can be prevented.