• Journal of Korean Society of Environmental Engineers
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• v.37 no.10
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• pp.573-577
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• 2015

There are difficulties in removing wood tar wastewater coming from the power plants that use wood-based fuels due to its intermittent occurrences and severe changes in the amount and concentration. This study investigated the treatment characteristics through physicochemical treatment, an improved method from the existing ones using bag filters and activated carbons to treat wood tar wastewater. In the case of chemical properties of wood tar wastewater, the content of phenols was found to be more than two times higher than that of guaiacols and carbohydrates. Installation is done to ensure that NaOH and PAC are injected automatically according to the change of pH, and then pH, turbidity and SS of the final treated water were examined. The results were 5.9, 12.6 NTU and 15.1 mg/L respectively, which confirmed the possibility of the treated water as circulation water of power plants. In the physical treatment process using a conventional bag filter, removal efficiency of chemicals was about 20%, but the treatment efficiency was improved to show chemical removal efficiency of about 80% through flocculation and sedimentation.

• Economic and Environmental Geology
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• v.57 no.2
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• pp.263-270
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• 2024

In this study, impact factors for dehydration with KOMIR-Tube system using flocculant and dewatering tube were evaluated for mine drainage sludges. The experiments were conducted on semi-active facility sludges with water contents above 90 % using KOMIR-Tube system. The flocculant and input amount were determined from laboratory experiment and the dewatering efficiency was verified onsite experiment. The sludge characteristics were identified by instrumental analysis such as zeta potential measurement, particle size analysis, XRD, XRF and SEM-EDS. Selection of flocculants for sludge dewatering treatment need to consider not only precipitated rate but also filterated rate. Floc size has to keep at least 0.7 mm. From on-site experiments, sludge dewatering using KOMIR-Tube system suggests to carry out April and May that is low rainfall and humidity considering to climate conditions. Also, dewatering rate depends on the crystal degree of mineral that mainly makes up sludges. Particularly, goethite of the iron hydroxides has better dewatering rate than ferrihydrite. Ferrihydrite is low degree of crystallinity and uncleared or broad shaped crystal, goethite is good crystallinity with needle shaped crystal so that the effect of flocculation and dewatering showed to depend on the crystal. In results, impact factors of dewatering for mine drainage sludges are related to flocculant, climate, crystallinity and shape of iron hydroxides.