Research On The Preparation Of Modified Fly Ash Composite Adsorbent And Its Adsorption Of Heavy Metal Ions

The treatment of heavy metal wastewater is a hotspot of research. With the increasing of the industrial and subsistent wastes in recent decades, many heavy metal contaminations entered into water by many ways and induced direct or indirect harm to environment and human health.Becouse of containing large amounts of active constituents, fly ash can be used in wastewater treatment. And its advantages can be shown such as simple,effective and low cost.Modification of fly ash can improve its adsorption ability greatly and so makes it adsorb the contaminants such as heavy metal ions in wastewater more effectively.The first section of the subject introduced the condition of the wastewater discharge and the adsorption ability of fly ash in wastewater treatment. Then discussed the background and the significance of the Subject.The second section show the research on the preparation modified fly ash composite adsorbent.l.fly ash hydration metal oxide was prepared with fly ash, ferric nitrate and aluminium nitrate as raw material.Observed its microstructure by SEM, and XRD FTIR to its structure an index. Influence to the removal rate of the preparation condition had been investigated through the nickel wastewater treatment.2.Polysilicate aluminum ferrite (PSAF) was prepared with fly ash as raw material, Observe its microstructure by SEM, and XRD FTIR to its structure an index, and the optimal preparation conditions were determined by orthogonal tests. Influence to the removal rate of the preparation condition had been investigated through the cadmium wastewater treatment.3.The composite adsorbent was prepared with chitosan and acid modified fly ash. Observe its microstructure by SEM and XRD, FTIR to its structure an index to processing manganese ion. Influence to the removal rate of the preparation condition had been investigated through the manganese wastewater treatment.The second section show the adsorption experiment of the adsorbent to heavy metal wastewater.1.wastewater single containing nickel ion,cadmium ion or manganese ion had been adsorbed with fly ash hydration metal oxide, PSAF and Chitosan crosslinked acid modified fly ash respectively. Influence to the.removal rate of the adsorption condition had been investigated.2. wastewater containing mixed heavy metals of nickel ion,cadmium ion and manganese ion had been adsorbed with fly ash hydration metal oxide, PSAF and Chitosan crosslinked acid modified fly ash respectively. Influence to the removal rate of the adsorption condition had been investigated.The result show:compared with the original fly ash, the adsorption of modified fly ash composite adsorbent have different degrees of improvement. Specific surface area increased and active group increased are the key factor of the improveing on adsorption effect.