하‧폐수처리공정 유출수와 매립장 침출수의 TOC 배출 특성

Abstract

In this study, TOC in the influent, reactor, effluent and sludge was analyzed to determine the TOC behavior in each process of a public wastewater and sewage treatment plant. Based on the introduction of industrial wastewater TOC effluent standard, the distribution characteristics of organic matter according to the type of business of the wastewater discharge facilities in the workplace were identified. The following conclusions were obtained through the comparison and correlation analysis between the distribution characteristics of the organic matter and the organic contamination index items according to the characteristics of the landfill leachate. 1. As a result of analyzing TOC in the sewage treatment plant, while the average TOC concentration of the influent ranged from 51.4 mg/L to 122.6 mg/L, the TOC concentration of the effluent ranged from 6.9 mg/L to 13.6 mg/L. Except for the TOC value 21.9 at the TI point, the TOC value in all points turned out to be within acceptable TOC criteria, which is below 15 mg/L. The TOC removal efficiency of each facility ranged from 87.6 % to 91.1 %, which was lower than the BOD removal efficiency of 93.6 % to 99.3 %, but the COD removal efficiency was similar to 87.6 % to 97.9 %. 2. The average influent and effluent CODMn/TOC ratio for the sewage treatment plant was 1.50 and 1.93. While the SUVA value of the influent was 0.8 L·m-1/mgDOC to 1.5 L·m-1/mgDOC and that of the effluent was 1.7 L·m-1/mgDOC to 2.0 L·m-1/mgDOC, and the influent and effluent consisted of hydrophilic and low molecular substances. The SUVA value of the influent was 3.6 L·m-1/mgDOC and the SUVA value of effluent was 3.9 L·m-1/mgDOC at TI point where the wastewater was introduced. Subseqqently, the introduction of hydrophobic aromatics and polymers was confirmed. 3. In the sewage treatment plant, 66.6 % ~ 73.1 % of the influent organic carbon was discharged the sludge. 17 % ~ 24 % was consumed via internal reactions, and about 10 % was discharged the effluent. Influent organic carbon in the sewage treatment plant is discharged in the sludge at 66.6 % ~ 73.1 %, 17 % ~ 24 % was consumed in internal reaction, and about 10 % was the effluent. 4. The CODMn average concentration in the wastewater from industry ranged from 1.1 mg/L to 79.0 mg/L, and the TOC average concentration was 1.0 mg/L to 147.9 mg/L. The highest COD and TOC concentrations for “fruit and vegetable processing and storage treatment facilities” were 79.0 mg/L and 147.3 mg/L. The COD and TOC concentrations for “coal mining facilities” were lower at 1.1 mg/L and 1.0 mg/L. respectively 5. The CODMn/TOC ratio between the organic matter indicators at each wastewater discharge facility was 1.5 ± 0.5. The correlation between CODMn and TOC for the 131 facilities surveyed was 0.8465, and 0.8630 to 0.9995 in 13 out of the total 17 industries surveyed. The correlation between CODMn and TOC for non-ferrous metal smelting, refining, and alloy manufacturing facilities was 0.6759 as a moderate correlation. The correlation between CODMn and TOC for fishery product markets and industrial water treatment facilities was negative. 6. The CODMn value of four facilities exceeded the CODMn effluent limit standard , but in the case of applying the TOC effluent limit standard, the TOC value of eight facilities exceeded the standard. As a result of industry type analysis a stricter TOC standard was applied to the following industries petrochemical product manufacturing, organic chemical product manufacturing and food industry. Although the food industry remains in compliance with the COD standard, it was found that the food industry is likely to be not in compliance when the standard is changed to TOC. 7. The concentration of organic matter in the raw water generated from the landfill leachate reflected the following characteristics: BOD was 19.8 mg/L to 79.4 mg/L, CODcr was 42.4 mg/L to 541.2 mg/L and TOC was 7.1 mg/L to 200.6 mg/L. the effluent from the landfill leachate reflected the following characteristics: BOD was 1.0. mg/L to 42.1 mg/L, CODcr was 2.4 mg/L to 131.4 mg/L, and TOC was 1.1 mg/L to 57.4 mg/L. The removal rate of organic matter for 5 samples of effluent from the landfill leachate was TOC 76.4% ~ 99.4%, CODcr 81.2 ~ 99.3 % and BOD 86.0 % ~ 99.5 %. 8. The relative BOD/TOC ratio of the raw leachate water was (0.17 ± 0.05) ~ (0.97 ± 0.88), the CODcr/TOC ratio was (1.91 ± 0.66) ~ (3.80 ± 1.45) and CODcr/TOC oxidation rate is 57.9 ~ 115.1 %. The relative BOD/TOC ratio of treatment water is (0.16 ± 0.13) ~ (1.88 ± 1.18), CODcr/TOC ratio was (1.74 ± 0.42) ~ (3.47 ± 1.70) and the CODcr/TOC oxidation rate was 52.8 ~ 104.9 %. 9. As a result of analysis of the correlation between organic material indicators in raw water of linked waters (n = 61), the TOC correlation coefficient for BOD was 0.245 and the TOC correlation coefficient for CODcr was 0.742. The TOC correlation coefficient for BOD was 0.676 and the TOC correlation coefficient for CODcr was 0.943. There was a high correlation between the organic indicators CODcr and TOC in the treatment water.