Performance of activated carbons in the catalytic wet peroxide oxidation (CWPO) of maleic acid

Abstract

Catalytic wet peroxide oxidation (CWPO) of maleic acid using palm fruit shell, peach stone and cashew nut shell as catalysts was investigated. Physical activation of pyrolised char with carbon dioxide was done at 900°C, 30 min holding time and heating rate of 20°C/min under nitrogen flowrate of 150 cm 3 /min. The activated carbons had maximum Brunauer Emmett-Teller (BET) surface areas of 389, 428 and 692 m 2 /g for palm fruit shell, peach stone and cashew nut shell, respectively. The morphology structures of the samples were determined using a scanning electron microscopy (SEM), while thermal stabilities were determined using thermal gravimetric analysis (TGA). The CWPO reactions were performed in a stirred batch reactor at an atmospheric pressure in the presence of H 2 O 2 as an oxidant. The results showed that peach stone and palm fruit shell catalysts are more effective for liquid phase oxidation of maleic acid than cashew nut shell and can be applied for catalytic wastewater treatment systems.

Seasonal examination of certain physical, chemical, and microbial parameters of Ardahan city tap waters

“…İçme suyu kirletici kaynakları; (i) yer altı ve yüzey suyundaki kirleticiler, (ii) doğal kirleticiler, (iii) içme suyunun arıtılarak dağıtılması sırasında oluşan kirleticiler olarak kategorilere ayrılabilir. Yer altı ve yüzey suyundaki kirleticiler; topraktan sızan doğal kirleticiler, tarımsal faaliyetlerden kaynaklanan akışlar, atıksu arıtma tesisleri, endüstriyel tesis atık sularının kontrolsüz deşarjı, düzenli depolama sahaları ve kimyasal kaza sızıntıları gibi nedenlerle oluşabilir (Herranz vd., 2018;Van Leeuwen, 2000;Kaale & Katima, 2013). Doğal olarak oluşan kirleticilerin çoğunluğunu, doğal mineral oluşumları ile elde edilen manganez ve arsenik gibi inorganik bileşikler oluşturmaktadır (Van Leeuwen, 2000;Goulle vd., 2009).…”