| Spent catalyst resurrection process produces acid heavy metal wastewater,which contains a large amount of aluminum. Direct emissions of heavy metal wastewater will seriously affect the ecological environment,and result in heavy metal waste of resources. So effectively remove heavy metal ions and separatio n technology has become a challenging task.Currently, the main heavy metal wastewater treatment method is divided into three categories, chemical method, physical and chemical method, biological chemical method. In this paper,research on the combination of two methods of resurrection of spent catalyst wastewater treatment,depending on the advantages and disadvantages of heavy metal wastewater treatment method at present.First, to fully understand the composition of wastewater,analyze the wastewater quality, including concentration of iron, nickel, zinc, copper and aluminum ion, turbidity, COD of wastewater, pH, etc. For wastewater composition analysis, and through the simulated wastewater and wastewater of neutralization, flocculation precipitation and method of experiment, the results show that aluminum elements in the resurrection of spent catalyst wastewater by complexing state exists in wastewater, the traditional chemical precipitation, with no obvious precipitation for its effect, and flocculation precipitation, precipitation effect is obvious.Second, composite flocculant was studied the influence of process conditions on the flocculation reaction, based on the temperature, pH, the molecular weight of flocculating agent, stirring speed, flocculant dosing quantity,the ratio of composite flocculant,etc. to determine the best flocculation process conditions. Results show that the wastewater treatment system at room temperature, pH around 7, PAM molecular weight is 16 million, flocculant dosing quantity of around 30 ml, the ratio of composite flocculant at about a quarter, flocculation precipitation incubation time is about 2 h, the stirring speed in 50 r/min, the flocculant flocculation effect is best.Finally, in order to reach the standard of recycling waste water, use the method of ion exchange to treat the low concentration of heavy metal ions of spent catalyst resurrection wastewater, and the influence factors of ion exchange process was investigated. By static experiments and dynamic experiments, t ypes of resins, resin consumption,initial pH and initial concentration of wastewater, reaction time, reaction temperature, waste water flow speed, exchanger layer height, the dosage and concentration of regenerant, to determine the best process conditions. Results show that the best model is 001 * 7, resin dosage is 2.5 g, pH = 3.64(raw water pH), reaction time 60 min, room temperature, initial concentration of waste water is 200 mg/L, waste water running speed is 4 L/h, aspect ratio is 1.2, the effect is best. Eluent concentration was 20%, the room temperature, the desorption time was 100 min, elution velocity is 3 L/h, elution effect is best. Continuous experiments show that the stability of ion exchange resin is good. Through to the isothermal equation fitting show that Langmuir isothermal equation is more suitable for resin adsorption process for aluminum. |
