In order to achieve the recycling of nutrients in photo-fermentation hydrogen production tailing liquid, the adsorption capacity of zeolite on NH₄⁺ and K⁺ in photo-fermentation hydrogen production tailing liquid was investigated using natural zeolite as adsorbent and kinetic and thermodynamic analyses were carried out. It is found that the adsorption of zeolite on NH₄⁺ and K⁺ in photo-fermentation hydrogen production tailing liquid exhibites a tendency of accelerated adsorption, then gradually reaches balance, which is attained at 2 h and 3 h of adsorption, respectively. When adsorption time is 2h and adsorption temperature is 35 ℃, zeolite demonstrates stronger adsorption capacity for NH₄⁺ with an adsorption of 1.82 mg/g. When adsorption time is 3 h and adsorption temperature is 45 ℃, zeolite exhibites its maximum adsorption capacity for K⁺, reaching 7.11 mg/g. The quasi-secondary kinetic model provides a superior description for the adsorption process. The adsorption process of zeolite on NH₄⁺ and K⁺ in the tailing liquid of photo-fermentation hydrogen production is non-spontaneous. The adsorption of NH₄⁺ by zeolite is characterised as an exothermic entropy reduction reaction, while the adsorption of K⁺ is identified as an adsorptive entropy increase reaction.

hydrogen  /  adsorption  /  kinetics  /  thermodynamics  /  zeolite  /  photo-fermentation hydrogen production tailing liquid