Study On Transition Of Organic Pollutants In Paper Effluent And Its Effects On Environment

Because of the nation condition and history, different from North America and European Union, which use BOD5 to measure the water quality, we regard CODcr as assessment criteria. But in terms of the paper effluent that contains natural plant fiber degradation ingredients, in fact, they are not harmful to basic public water environment after biochemical treatment. If we still use CODcr as assessment criteria, we should develop further treatment to meet the emission stardards. But the chemical sludge that is difficult to bio-degradation will be produced during further treatment, soil and water will be polluted at the same time, which is more harm than good.In view of this circumstance, this paper studied the transition of papermaking effluents; the contribution of cellulose, hemicellulose and lignin for CODcrand the effects of Fenton treatment on the removal ratio of CODcr and chemical sludge. This paper explored the sources and production of CODcr and the characteristics and the amount of chemical sludge, in order to offer data reference.Firstly, this paper selected three type of pulp (DIP、APMP、BKP) as research objects to make simulated fines and effluents. Under the circumstance of simulating natural water, this paper analyzed the three kinds of effluents of a certain cultivated period (0-180d), and studied the variation of the chemical components of every 30 days, morphological characteristics and microscopic characteristics of fines. The results indicated that after 180 days, the remaining ratio of BKP effluent was least. The degradation ratio of cellulose, hemicellulose and lignin of BKP fines was faster than those of DIP and APMP fines obviously, and the BKP fines was more divided than DIP and APMP fines.Secondly, this paper studied the variation of three kinds of effluents with respect to CODcr, BOD5, pH and SS during a certain cultivated period (0-180d). The result indicated that after 180-day natural cultivation, the pollutant concentration of BKP was lower than DIP and APMP effluent, and the biodegradability of three kinds of effluent became worse.Thirdly, this paper regarded original fines of DIP, APMP and BKP as research objects to measure contribution ratio of CODcr of each organic component by conducting benzyl-alcohol extraction treatment, KMnO4 treatment and 12% HCl treatment successively, measuring CODcr of the remaining materials imultaneously. This paper explored tentatively of the contribution of cellulose, hemicellulose and lignin for CODcr.The result indicated that the contribution of cellulose was maxium in the three kinds of fines, and the CODcr amount of benzene-alcohol extractives was maxium in the three kinds of fines.Finally, this paper optimized the Fenton treatment of secondary biochemical effluent by orthogonal experiment and single factor experiment, and discussed the effects of Fenton treatment on the removal ratio of CODcrand chemical sludge.The results indicated that the order of significance of influence factor in Fenton treatment was: H2O2 dosage> c[H2O2]:c[Fe2+]>pH value>reaction time. And in the optimal Fenton condition, the removal ratio of CODcr was 80.20%. In the optimal Fenton condition obtained by single factor experiment, the removal ratio of CODcr was 88.79%.