Study On Adsorption Characteristics Of Phosphorus And Selenite On Modified Lobster Shell

The oxygen-rich oxidation of water caused by the extensive use of phosphorus poses a huge hazard to humans,aquatic organisms and the aquatic environment.Selenium is an essential element of the human body,but excessive selenium is harmful to human health and ecological safety.In this paper,the oxidized lobster shell was used as the adsorbent to explore the adsorption characteristics of phosphorus and selenium in the modified lobster shell,and the mechanism of phosphorus removal and selenium removal was clarified.The characteristics and mechanism of adsorption and phosphorus removal were studied by using iron modified lobster shell as adsorbent.The results show that the adsorption efficiency of phosphorus removal in the 4g/L iron-modified lobster shell is the best.For wastewater below 20mg/L phosphorus concentration,the efficiency of adsorption and phosphorus removal is over 91.6%.The iron-modified lobster shell absorbs phosphorus.The suitable pH range is wide,and the coexisting ions have little effect on the adsorption and removal of phosphorus by the iron-modified lobster shell,and HCO3-has a weak inhibitory effect.The Freundlich equation can describe the adsorption behavior of phosphorus on iron-modified lobster shells,and the adsorption process follows a quasi-secondary kinetic model.Thermodynamic analysis shows that the adsorption process is spontaneous.X-ray diffraction and Fourier transform infrared spectroscopy indicated that the main mechanisms of phosphorus removal by iron-modified lobster shells were coordination exchange,electrostatic interaction and surface precipitation.The modified lobster shell was used as adsorbent to study the characteristics and mechanism of adsorption and selenium removal.The research shows that the adsorption efficiency of solid-liquid ratio 5g/L is the best,and the adsorption efficiency of 5mg/L low-concentration selenium wastewater is high.The iron-modified lobster shell is suitable for adsorption and selenium removal under acidic conditions.H2PO4-in the coexisting ions Significant inhibition,while Ca2+has a significant promotion.The Freundlich equation can well describe the adsorption behavior of selenium on iron-modified lobster shells,and the adsorption process follows a quasi-secondary kinetic model.Thermodynamic analysis showed that the adsorption process of selenium by iron-modified lobster shell was spontaneous.The results of mechanism analysis indicated that the mechanism of adsorption of selenium in iron-modified lobster shells was mainly complexation,coordination exchange and electrostatic interaction.The characteristics and mechanism of adsorption and selenium removal were studied by using zirconium modified lobster shell as adsorbent.The results show that the efficiency of adsorption and selenium removal is 98.7%when the solid-liquid ratio is 7g/L,and the selenium removal efficiency is more than 91%for the wastewater with less than 50mg/L selenium concentration.The effect of pH on the adsorption and selenium removal efficiency of zirconium modified lobster shell is not obvious.Influence,H2PO4in the coexisting ions has obvious inhibitory effect.The Freundlich equation can describe the adsorption behavior of selenium on zirconium-modified lobster shells,and the adsorption process follows a quasi-secondary kinetic model.Thermodynamic analysis shows that the higher the temperature,the easier the adsorption reaction proceeds.The results of mechanism analysis indicated that the mechanism of adsorption of selenium in zirconium-modified lobster shells was mainly complexation and coordination exchange.