EMISSION OF VOLATILE PHENOLS FROM STABILIZATION PONDS OF OIL SHALE ASH DUMP LEACHATE
H. KUNDEL
V. LIBLIK
Tallinn University of Educational Sciences,
Institute of Ecology
North-East Estonian Department
15 Pargi St., Jõhvi
41537 Estonia
| The Viru Chemistry Group AS oil shale processing plant at the town of Kohtla-Järve in the North-East of Estonia uses stabilization ponds with a total area of 16.3 ha for stabilization of pH and concentration of phenols in the leachate from semicoke dumps. At pH ~11 and a background concentration of phenols ca 5 µg m–3 in the atmosphere over the water surface, the emission of phenols from leachate into the air remains minimal, while the maximum emission intensity of phenols equals 0.0035 g s–1 (by an annual quantity about 0.07 t) if the water pH decreases down to 9.4. The total annual emission of phenols during the course of water from stabilization ponds via a special channel into the Kohtla and Purtse rivers and finally into the Gulf of Finland equals ca 12 t. The formulas are elaborated for calculation of emission intensity and annually emitted amount of phenols into the air, depending on leachate temperature and pH, as well as on phenols concentration in the water and their background level in the air. |