Study On Process Techniques For Chloronitrobenzenes Manufacture Wastewater And Theirs Engineering Application

The chloronitrobenzenes(CLNs) waste-water in Changshan Chemical Limited Corporation was studied in this thesis. Through determining the representative pollutants in the wastewater, we studied on the biological toxicity and biodegradation of these compounds, and seeked a novel effective treatment process and its application to full-scale, the results showed that:(1) There were several poisonous and non-degradation aromatic compounds in the CLN wastewater of Changshan Chemical Limited Company, which were 1,3-dimethylbenzene (1,3-DMB), o-chlorophenol(o-CP), o-chloroaniline(o-CA), o-nitrophenol(o-NP), w-chloro-phenol(m-CP), 772-chloronitrobenzene(/72-CNB), 3,4-dichloroaniline(3,4-DCA), /7-nitrophenol (p-NP), nitrobenzene (NB), /?-chloronitrobenzene(p-CNB), o-chloronitrobenzene(o-CNB) and chlorobenzene(CB). NB, p-CNB, o-CNB and p-NP were representative pollutants in the wastewater and was chosen as target polluants in toxic experiment, the result showed the toxic sequence of aerobic and anaerbic sludge was p-NP>p(oj-CNB>NB, /Yo,)-CNB>NB>/;-NP respectively. Aerobic and anaerbic sludge both had the ability to transform nitroaromtic compounds(NAC) into aminoaromatic compounds(AAC) and mineralize AAC then, which was demonstrated in the experiment.(2) The experiment demonstrated that it was feasibile to treat chloronitrobenzene wastewater with A/O process. With COD<600mg/L, hydraulic retention time(HRT) 44h(A 22h, 0 22h), the concentration of polluants and COD in the effluent could meet the second discharge standard of GB8978-1996. Comparing the treatment efficiency of A/O process with that of single SBR(sequencing batch reactor), it showed the efficiency of A/O process was obvious higher than that of single SBR process. DCA and o-CNB were not transformed completely in A/O system, but other pollutants, such as CP, NB, NP, p-CNB, m-CNB, were transformed or degradated effectively. It was necessary for us to seek economical and effective pretreatment method for the wastewater in order to stabilize the treatment system.(3) The results of experiment-scale study, in which the manufacture wastewater was treated with Fe/C-A/O-oxidation/flocculation process, showed that: with COD 1241-1608mg/L, NAC 52-69.2 mg/L and AAC 161.1~260.2mg/L in the mixing wastewater, Fe/C reduction for 1 hour, A/0 HRT 36-48 hours, adding 0.5~2~%oFe3+ or !%~2%NaClO for oxidation/flocculation, the concentration of pollutants in the effluent were COD<150mg/L, AN