Adsorption and recovery nutrient from the tail liquid of biohydrogen production by zeolite.

In order to reduce environmental pollution caused by biohydrogen production tailing liquid (BHPTL) discharge and realize waste reuse of BHPTL, zeolite was selected as adsorbent to recycle nutrients contained in BHPTL, and the adsorption and desorption characteristics of zeolite acting on BHPTL were investigated. The results showed that the amount of zeolite added had a strong effect on the adsorption effect of NH₄⁺ and K⁺, and the reaction temperature and solution pH had a weak effect on the adsorption effect of NH₄⁺. The adsorption (desorption) time had a significant effect on the adsorption (desorption) process of K⁺, but had less effect on the adsorption and desorption process of NH₄⁺. The maximum adsorption rates of NH₄⁺ and K⁺ in zeolite were 79.05% and 66.33%, corresponding to desorption quantities of 0.616 mg/g and 4.00 mg/g. In addition, the equilibrium desorption rates of NH₄⁺ and K⁺ in zeolite were 58.49% and 35.84%, corresponding to desorption quantities of 0.38 mg/g and 1.56 mg/g. The adsorption process of zeolites conforms to the quasi-secondary kinetic model and is dominated by chemisorption processes. This study provides a theoretical basis for the recovery of nutrients from BHPTL to produce useful substances, such as fertilizers and soil conditions. [ABSTRACT FROM AUTHOR]