Process and Experimental Study on Synthesis Treatment of Glycine Wastewater
|School||Hebei University of Technology|
|Course||Chemical Process Equipment|
|Keywords||Glycine Wastewater treatment Evaporation Formaldehyde Methanol Ammonia Stripping Catalytic Oxidation|
Glycine industrial wastewater contains large amounts of toxic and hazardous substances, direct discharge of wastewater if not governance, is bound to bring a little evil to the environment. In this paper, the actual production of the Hebei Donghua Chemical Group as a background process and experimental study of the comprehensive management of the industrial wastewater, the First multi-effect evaporation recycling ammonium chloride, then condensate governance to the comprehensive management of the program. Multi-effect vacuum evaporation and heat pump technology recovery of ammonium chloride process, this process solutions the conventional evaporation energy consumption as well as the feed solution corrosion of equipment problems. Glycine industrial wastewater containing a large number of substances such as ammonium chloride, hexamine, ammonia, formaldehyde and methanol, in the evaporation of the secondary steam condensate water recovery of ammonium chloride process is still a lot of ammonia, methanol, and a certain amount of formaldehyde and hexamine exist completely remove condensation water pollutants, so that the final water discharge standards the Difficulties and priorities of the wastewater treatment. Governance condensate using a stripping - catalytic oxidation - secondary stripping governance process is determined by comparison of the various methods of treatment of pollutants. A stripping process to remove the condensed water, ammonia and methanol, the optimum operating conditions for one-stripping: pH value of 9.4 or so, stripping temperature of 333K, the gas-liquid ratio 3200; catalytic oxidation process to deal with the substance formaldehyde, methanol, and methenamine. Oxidation time 1.5h, half an hour before adding hydrogen peroxide, methenamine fully decomposed to ammonia and formaldehyde in this time period, half an hour later, hydrogen peroxide using fractionated dosing join the degradation of methanol and formaldehyde. Several major influencing factors in the process of catalytic oxidation by orthogonal experiments the optimum operating conditions: temperature of 358K, H 2 O 2 : CH 2 < / sub> O = 6 to 7, Fe, 2 sup>: H 2 O 2 (mass ratio) = 4, a pH of 2.5; secondary stripping hexamine decomposition of ammonia nitrogen removal in the catalytic oxidation process, The second stripping optimum operating conditions were as follows: about pH value of 10.45, stripping temperature of 333K or so, the gas-liquid ratio 525. Ammonium chloride recovery - the comprehensive management of the condensate governance programs glycine liquid waste treatment, and ultimately water ammonia content of 20mg / L, COD dropped to less than 500mg / L, the formaldehyde content of less than 5mg / L, pH lt; 9, the indicators have reached the national emission standards, normal emissions.