| Methylamine manufacturing wastewater has the characteristics of high CODcr, highorganic matter (methanol) and ammonia nitrogen. Experimental study was done in the paper about the reutilization of methylamine manufacturing wastewater.Reutilization of ammonia nitrogen and methanol was respectively studied by chemical precipitation and distillation in the experiment, and the optimal conditions on deposition of ammonia nitrogen and recovery of methanol were determined firstly by orthogonal experimental and single factor optimization experiment. During recovery of ammonia nitrogen, the optimum recovery conditions were determined by the change of the variety and mass of magnesium salt and phosphate input, reaction time, the speed of sirring, pH value, reaction temperature, the last product was MAP as a slow release fertilizer; The optimum recovery conditions of methanol from methylamine wastewater was determined by the change of the mass of masking agents, holding time, holding temperature. Based on the optimum recovery conditions of ammonia nitrogen and methanol, a technical recovery proposal of good effect and easy to control was final to be determined to treat methylamine manufacturing wastewater. The main conclusions of experiment and analysis were as follows:(1) The optimal conditions on deposition of ammonia nitrogen from methylamine manufacturing wastewater were: pH = 9.37, n(PO43-) : n(NH4+) = 1.00, n(Mg2+) : n(NH4+) = 1.10, the reaction time 15min ,mixing speed 150r/min. In the condition, the experiment results demonstrated that the better removal rate of ammonia nitrogen was up to 92.46%, the concentration of remained ammonia nitrogen was kept 21.94 mg/l and the removal rate of CODcr was 37.38%-40.52%.(2) The optimal conditions on deposition of methanol from methylamine manufacturing wastewater were: holding temperature 85℃, holding time 180min, masking agents(acidity:( ammonia and amines)) 1.1. In the condition, the experiment results demonstrated that the recovery rate of methanol kept was up to 85.11%, the removal rate of CODcr was 23.12%-33.50% and the efficiency of masking agents 97.10%-98.45%.(3) The efficiency of methanol and the removal of ammonia nitrogen were respective 83.66%-85.16% and 91.04%-91.23% in the experiment of reutilization recovery of methylamine manufacturing wastewater. The concentration of remained ammonia nitrogen and methanol were respective 20.00mg/1-30.00mg/l and about 0.40g/l. The efficiency of removal CODcr was kept about 65.00% and the efficiency of masking agents was above 97.00%. So not only ammonia nitrogen and methanol had a high removal and recovery efficiency, but masking agents had a higher masked efficiency in the distillation experiment.(4) There was no great difference in the nitrogen in MAP of formation of deposition. Compared to theoretical components of MAP, the contents of P2O5 and MgO were higher, the purity of MAP was up to 86.74%. This could be ascribed to a little of products of side effect, the last product was MAP as a slow release fertilizer for crops.(5) Although higher concentration methanol was recovered and masking agents had a higher masked efficiency in the experiment reutilization of methylamine manufacturing wastewater, the recovery had impurities. So purification and distillation were needed for mixture. Ammonia nitrogen, phosphate and methanol were remained in the effluent, biochemical treatment was applied in the the effluent for cyclic utilization.The method of deposition and distillation could realize higher deposition of ammonia nitrogen and distillation of methanol in the experiment of reutilization recovery of methylamine manufacturing wastewater. The deposited product was MAP as a slow release fertilizer, semifinished methanol wasw needed for further rectification and purity. There had a important significance for studying reutilization of methylamine manufacturing wastewater to realize the recovery and cyclic utilization of methanol and ammonia nitrogen in the shortage of resource modern. Figure 35 table 35 reference 70...
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