The need for clean water is the most basic human right. Water scarcity will be one important environmental problem of all countries in the future. Phosphate is a harmful matter for public health and the environment. In this study, the removal of phosphate from water by chitosan, which is an environmentally friendly material, was investigated. Chitosan adsorbent spheres were prepared for phosphate separation from water by adsorption, which is a feasible method. The effects of phosphate concentration, adsorbent dosage, and operation time on the removal were investigated. The removal increased with acid concentration and adsorbent amount. The maximum adsorption capacity of chitosan beads is 87.26 mg/g. Adsorption behavior of the chitosan beads were examined by Langmuir and Freundlich isotherms and pseudo-first and second-order kinetic models. The adsorption process was optimized by the response surface method (RSM). Trial version of Design Expert® 12.0 was used in the study. It has been understood as a result of the RSM statistical analysis that higher phosphate removal values would be obtained by increasing the amount of adsorbent. ANOVA analysis showed that adsorbent dosage had the biggest effect on removal of phosphate using chitosan beads prepared for adsorption.

Dimethyl carbonate (DMC) is a green solvent, environment friendly fuel additive. It is produced by carbonylation of methanol The production cost of DMC is very high by conventional process. Because DMC and methanol forms azeotrope and can not separated by distillation. Its separation can be made by pervaporation (PV) economically. Pervaporation (PV) is an environment friendly membrane process also in which liquid-liquid mixtures are separated under vacuum with high selectivity. Pervaporation selectivity is dependent to sorption selectivity and diffusion selectivity. Membrane used in pervaporation process is a semi-permeable barrier and provides selective separation and transport. In PV development of an appropriate membrane material is important for obtaining pure substances. Hydrophilic membrane can separate methanol that is a polar component. Chitosan is a harmless, biosoluble, natural polymer and has hydrophilic property. But it does not resist to aqueous conditions. Therefore it should be modified by crosslinking. Tetraethoxysilan (TEOS) and tungstophosphoric acid (TPA) can be used as crosslinking agent and additive blending component in membrane production for increasing chemical and mechanical stability. In this study, sorption tests were carried out to determine the usability of chitosan-tetraethoxysilan (TEOS) and chitosan-Tungstophosphoric acid (TPA) hybrid membranes in separation of DMC-Methanol mixture with PV.

Dünyada temel endüstrilerden biri olan kimya endüstrsinde katalitik reaksiyonlar kimyasal üretimin büyük kısmını oluşturur. Ayırma saflaştırma işlemlerinde sıkça kullanılan membran teknolojisi, katalizör teknolojisi ile birleştirilince, oluşan yeni hibrit yapılarla daha çevreci katalitik proseslere katkı sağlayabilir. Elde edilen hibrit yapıdaki katalitik membranlar kendi içlerinde reaksiyon ve ayırmayı beraber gerçekleştirirler. Böylece ek ayırma birimleri gerektirmezler. Reaksiyon sonucu yan ürünü tutarak veya geçirerek reaksiyon dönüşümünü arttırabilirler. Katalitik membranlar heterojen yapılı olduğu için reaksiyon karışımından geri kazanımları kolaydır. Etkinliklerinde çok az bir azalmayla tekrar kullanılabilirler. Kimya endüstrisinde sıkça rastlanan esterleşme reaksiyonlarında etil astetat, etil laktat, izopropil asetat üretiminde, transesterleşme reaksiyonlarında fosil yakıtlara çevreci bir alternatif olan biyodizel üretiminde, asetalizasyon reaksiyonlarında yakıt katkı maddesi ve parfümlerde kullanılan güzel kokuların üretiminde reaksiyonu katalizlemek ve dönüşümü arttırmak için kullanılırlar. Bu çalışmanın amacı katalitik membranlarla ilgili yapılacak çalışamalara ışık tutmaktır. Yapılan bu çalışmada üretimlerinden, kullanıldıkları reaksiyonlardan, katalitik reaksiyonlarda sağladıkları avantajlardan, kullanım koşullarından söz edilmiştir.