Biochemical-Physicochemical Treatment Research Of Explosive Wastewater

Explosives industry wastewater contains various compounds such as large molecule difficult to decompose and high nitrogen molecule toxic, so it is antiblastic to familiar microorganism and its biochemical decomposition is inefficient. For the biochemical method is an economical and little derivative contamination technique, the combination of biochemical method and physicochemical method should be researched to obtain a technique adaptable for explosives wastewater treatmentThree worldwide explosives 2,4,6- trinitrotoluene (TNT), hexahydro-1,3,5-trinitro-1,3,5- triazine (RDX) and octahydro-l,3,5,7-tetranitro-l,3,5,7-tetrazocine (HMX) were discussed. The simulated wastewater, which contains the three explosives, and industrial explosives mixture wastewater were selected as samples. Anaerobic bacterium and aerobic bacterium were cultivated and domesticated at first and anaerobiosis - aerobiosis - flocculation sedimentation process technique was then adopted to treat the industrial explosives mixture wastewater which included the intermittent anaerobic ferment reactor, activated sludge jetting bed and flocculation sedimentation basin.Trial experiments were given here. The biochemical decomposition of anaerobic sludge to simulated wastewater was improved remarkably. BOD5/COD increased from 0.30 to 0.43 and BD% reached 86.9%; the biochemical decomposition rate of aerobiosis sludge to simulated wastewater was improved remarkably .Rx/R₀ of sludge after domestication of 20 days increased about 1¹.5 times compared with that after 10days; domesticated sludge could endure the concentrated wastewater. The anaerobiosis - aerobiosis - flocculation sedimentation process technique detailed here could be effective in the treatment of explosives mixtures wastewater. The CODcr decreased by 98.4%, SS decreased by 92.9%, the treated water reached the ordnance standard; TNT in the explosives wastewater decreased by 98.7%, anaerobiosis decomposition was in accord with first order reaction, its kinetic equation was C = 100exp(-0.034t), its rate constant k =0.034h^l(35"C); aerobiosis decomposition was in accord with first order reaction, its kinetic equation was C = 7.77exp(-0.0345t), its rate constant k = 0.0345h'I(27°C); RDX in the explosives wastewater decreased by 97.6%, anaerobiosis decomposition was in accord with first order reaction, its kinetic equation was C = 100exp(-0.0379t), its rate constant k = 0.0379h"I(35°C); aerobiosis decomposition was in accord with first order reaction, its kinetic equation was C = 5.44exp(-0.0109t), its rate constant k = 0.0109h"](27°C); HMX in the explosives wastewater decreased by 93.8%, anaerobiosis decomposition was in accord with zero order reaction, its kinetic equation was C = -1.2548t + 100, its rate constant k = -1.2548h"1(35°C); aerobiosis decomposition was in accord with zero order reaction, its kinetic equation was C = -0.0829t + 11.9, its rate constant k = 0.0829h''(27°C).Fishes feeding experiments were processed to compare emission water to untreated wastewater. Fishes died soon in untreated wastewater while survived more than one month in emission water. Toxicity of the water was decreased evidently during anaerobiosis - aerobiosis - flocculation sedimentation process.