Study On The Preparation And Application Of Modified Lignin Sulfonic Acid Sodium Salt Of Heavy Metal Adsorbent

In this paper, the raw material-sodium lignosulfonate is synthesized into heavy metal adsorbent with high molecular weight through amination modification.The optimum technological conditions of and the structure of the products are studied. It also discusses the adsorption properties of modified sodium lignosulfonate heavy metal adsorbent used in heavy mental wastewater, including the research on dynamics in the process of adsorption. The results show that:1. Sodium lignosulfonate and urea are used as raw material,formaldehyde as cross-linking agent. The optimum synthesis technology for modified sodium lignosulfonate through oxidation pretreatment and then amination synthesis is as follow:mass ratio of Fe2+and H2O2for oxidation pretreatment Fenton is1:5; the molar ratio of reactive formaldehyde and urea nitrogen is1:3; the reaction temperature is80℃and reaction time is4hours.2. The results analyst by the Kjeldahl nitrogen determination apparatus and Near Infrared Spectroscopy Analyzer show that the amino can have Mannich reaction with aromatic ring group of sodium lignosulfonate.The target product is determined to be modified lignin amine through functional analysis.The porous structure of the modified product is more obvious than that of the original material and the surface structure is looser through Scanning electron microscopy.3. The modified Sodium Lignosulfonate adsorption capacity for copper, lead,will be affected by the initial concentration, pH value, adsorption time and adsorption temperature of the adsorption of heavy metal ions effects.But the effects of pH and temperature is little, the unmodified Sodium Lignosulfonate adsorption capacity for copper, lead is very small, almost no absorption. The modified sodium lignosulfonate as heavy metal adsorbent used in heavy metal waste water.The best application conditions is:the adsorption at room temperature, pH is neutral, the adsorption time1h.4. Study the thermodynamics and kinetics of the adsorption process of copper by the modified Sodium Lignosulfonate.The Langmuir equation and dynamic two equations are the best fitting of the modified Sodium Lignosulfonate adsorption process for copper, lead.Thermodynamic and kinetic studies indicate, modified SL adsorption material on lead adsorption saturation and the adsorption capacity is greater than the adsorption of copper.The stability of lead ion Combined with modified SL adsorption material is greater than the copper ion. Modification of lignin sulfonate adsorption on copper, lead to porous solids monolayer adsorption. The adsorption process is slow adsorption process.