Utilization Of Glyphosate Wastewater

As human beings increasingly attach importance to the environmental and ecologicalprotection, the national policies for glyphosate production are becoming increasingly strict.Therefore, it is with great environmental and economic benefits to investigate GlyphosateWastewater Utilization. In this paper the adsorption-desorption method combined with theacephate production technology was employed to treat the glyphosate wastewater so that amore environment-friendly process can be achieved. This method prevents environmentalpollutions from the production process, and facilitates wastewater utilization at the same time.During the adsorption stage, the best adsorbent was selected by comparing the staticadsorption effects of different adsorbents; Regression was carried out to fit the adsorptionequilibrium curve and the kinetic equation. The effect of the best absorbent was verified forreal industrial wastewater. The results showed that: the D301resin can be a relatively goodsolution for the adsorption of glyphosate. Below328K, the adsorption properties won’t beaffected whether or not the resins were dried; The adsorption rate of D301resin forglyphosate increases with increased amount of resin, however, the increasing rate becomesgradually slower. The optimum resin: glyphosate wastewater feed ratio is1:10; At roomtemperature, it takes4hours for the adsorption to reach equilibrium, and with increasinginitial concentration, the adsorption capacity and the equilibrium concentration will increaseaccordingly. The adsorption process can be well described by the pseudo second-order kineticmodel, while adsorption of glyphosate by D301resin fits the Freundlich isothermaladsorption model. Impurities in the real wastewater will compete with the glyphosate for theadsorption sites, thereby reduce the D301resin adsorption rate of glyphosate, but theregeneration performance of D301resin will not be affected after treating the real wastewater.During the desorption recovery stage, the best desorption agent was determined bycomparing the economic and the static desorption effects of different desorption agents.Factors affecting the desorption effect were analyzed; the desorption kinetic equation wasfitted, and the re-use effect was verified. The results showed that: Ammonia could be used asthe desorption agent of this process; with the increase of ammonia concentration, theincreasing rate of desorption will gradually reduce. The desorption rate reached the maximumwhen ammonia concentration was3%. After that, the desorption rate approached the same oreven decreased slowly with increasing ammonia concentration; The optimum feed ratio forthe D301-PMG: ammonia is1:1.2; At room temperature, desorption equilibrium time is about2hours, the desorption process fits the pseudo-second order kinetic model; When the resin reaches the maximum adsorption capacity, glyphosate content in the desorption solution canreach11.06%, and the desorption rate is82.7%under the optimal experimental conditions; theresin can be reused more than6times. The main factor that influences the effect of recyclingis the breakage of the resin.The acidic wastewater from the production processes of O-methyl thiophosphoryldichloride was used as the substitute of concentrated sulfuric acid to neutralize the aqueoussolution of glyphosate in aftertreatment of synthesising glyphosate. The results showed that:the presence of methanol has little or no influence on the crystallization, and this integrationprocess is feasible. When the mass fraction of glyphosate ammonium salt is10%, feed ratiofor the solution: wastewater is1:0.79, crystallized glyphosate content is97.2%, and the yieldis74.6%.