Competitive adsorption of N, P and Cu in aqueous solution on organic-inorganic complex

In this paper, the organic-inorganic complex prepared by degradation of liquid manure and bentonite was used as adsorbent. And NaNO₃ was used as nitrogen salt, KCL as potassium salt, and CuSO₄ · 5H₂O provided Cu²⁺. Different concentrations of nitrogen and potassium salt were prepared to carry adsorption reaction with certain concentration of Cu²⁺ in aqueous solution. Through these experiments, study that whether a competitive adsorption occurs between nitrogen, potassium nutrients and Cu²⁺ or not, as well as the variation of adsorption rate of Cu²⁺ in different concentrations of nitrogen and potassium nutrients. The study results show that: (1) NO₃^- affects the adsorption rate of Cu²⁺. As the concentration of NO₃^- increases, the adsorption rate of Cu²⁺ decreases. When the concentration of NO₃^- is larger than a certain value, the adsorption rate of Cu²⁺ will increase gradually. (2) There is competitive adsorption between K⁺ and Cu²⁺, with the increase of concentration of K⁺, the adsorption rate of Cu²⁺ decreases gradually.