Treatment Of Analog Wastewater From RDX Obsolete Ammunition Disassembling

Disassembling RDX Obsolete ammunition will produce large amounts of toxic waste.This wastewater has some characteristics,such as toxic,high concentrations ofpollutants,saturated, poor biodegradability.It will cause serious pollution to the ecolo gicalenvironment if it does not untreated. Currently, treatment of such wastewater has a lot ofdifferent method which reported in the literature.By researching the factors of four methods, we got optimal conditions of each method.The main contents include:(1)Developing a highly efficient bacteria degrade RDX.Studyoptimal growth conditions of the bacteria and optimal conditions for treatment of suchwastewater.(2)Using UV/Fenton method dispose RDX wastewater.Study the optimumconditions by orthogonal experiments.(3)Using DSA electrochemical method disposewastewater.Study the optimum process conditions by single factor experiments andorthogonal experiments, the.(4)Using three-dimensional electrode electrochemical methoddisposed wastewater. Study the optimum conditions by orthogonal experiments.(5)By meansof GC-MS methods, analyzed and discussed the mechanism of electrochemical degradation ofthe wastewater.By using various methods to study and analysis the experimental results, getthe following conclusion:(1) Using aerobic bacteria dispose RDX wastewater,due to some problems ledding to thefailure.Determined the concentration of RDX, the calculation results are negative value. Thebacteria was cultured in nitrogen deficiency medium which can induce degrading activity ofthe bacteria, but the results show no effect.During the training, the bacterial has contaminated.(2) Fenton reagent is the best treatment.The optimum conditions of UV/Fenton dispose30mL40mg/L RDX wastewater are pH3, H2O20.4mL, H2O2:Fe2+=10:1,processing time60min. Under these conditions, RDX remove88.60%and the content of RDX is4.56mg/L.The value of COD is44mg/L.(3) RDX can be effectively removed using Ti/TiO2-RuO2-IrO2, Na2SO4and NaCl. Whenthe concentration of RDX is40mg/L，the best operation parameters are:pH6.5, Na2SO4mass12.5kg/t, NaCl mass0.567kg/t, voltage5V, reaction time55min. RDX remove96.1%and the mass of RDX is1.56mg/L. The value of COD is35.2mg/L, which complie to the dischargestandard for water pollutants. Although the concentration of Cl-in the water reached theeffluent discharge standards,there may be cause secondary pollution.(4)Activated carbon as a three-dimensional electrode and Na2SO4as a electrolyte canachieve the desired effect. The optimum conditions are Ti/TiO2-RuO2-IrO2as anode, pH6.5,carbon dust mass10kg/t and Na2SO4mass5kg/t, voltage6.5V, processing time120min.Under these conditions, RDX remove94.85%and the content of RDX is2.06mg/L,whichreached the national standards. Added toner needs filtration and drying.They increasedtreatment costs and operating processes.(5) Comparison and analysis of the three methods from the experimental conditions,treatment effect, the cost, operation processing, etc,DSA electrochemical method has a normaltemperature and pressure condition, the least time, the best treatment effect,and can meet thenational standards. The consumption,energy consumption and drug use of DSAelectrochemical is relatively low.It has the lowest processing costs (50.87yuan/t) and simpleprocess, not adjust pH, without filtration,without subsequent processing. Above all, DSAelectrochemical method has obvious advantages.(6) The metal oxide of active electrode Ti/TiO2-RuO2-IrO2oxidize organic compoundswho adsorbed onto the electrode surface from cheap state to expensive state. There are twopaths of indirect oxidation. One is producing OH in water, the other one is chlorineproducing Cl2and OCl-which accelerate the reaction and play a major role.(7) By means of GC-MS methods, analyzed the mechanism of electrochemicaldegradation of the wastewater.Using mass spectrometry and added NaCl, RDX degradationproducts may have four kinds of chloride-containing, including chloroform, dichloroaceticacid, dichloro nitrous methane,2-propanol,1-chloro.Based on RDX degradation pathways andprocesses which reported in the literature and infer the possible degradation of RDX. Beforeheterocyclic openning, remove nitro group or hydrogen on carbon oxidized to a hydroxylgroup. After heterocyclic disconnecting, generate a single-CH3.It can combinate a chain orcombinate with-NO2, and reacted with the product of chlorine.