Ammonium and potassium removal from swine liquid manure using clinoptilolite, chabazite and faujasite zeolites.

This study concerns cationic exchanges performed in order to remove ammonium and potassium cations from manure by using various zeolites: clinoptilolite, chabazite and NaX faujasite. First, the effect of temperature (25 °C and 40 °C) on the exchange rate between zeolites and an ammonium chloride solution was investigated. Then, cationic exchanges were performed on these three zeolites using on one side a mixed ammonium and potassium chloride solution reproducing the chemical composition of a swine manure and on the other side the corresponding liquid manure. No significant difference was observed on the exchange rate and the trapping of ammonium cations by changing the temperature (25 or 40 °C). Clinoptilolite showed a good selectivity towards ammonium cations using model (NH4Cl, and mixed NH4Cl/KCl) solutions but is less efficient with the liquid manure. Chabazite and faujasite were found more efficient than clinoptilolite for trapping ammonium cations. However, NaX faujasite enables trapping 3 times more ammonium cations than chabazite from manure (60 and 20 mg/g, respectively). Moreover, chabazite allowed to trap the same amount of potassium cations than NaX faujasite (33 and 35 mg/g, respectively).