INVESTIGATION INTO EMISSIONS OF GASEOUS POLLUTANTS DURING SEWAGE SLUDGE COMPOSTING WITH WOOD WASTE

The main environmental problem of sewage sludge treatment and storing processes is unpleasant smell caused by emitted gases, such as NH3, H2S etc.; which are released during organic matter decomposition process. The second environmental problem is that during sewage sludge composting process global warming gases, such as CO2, CH4, and N2O are emitted, the emissions of these gases can be reduced by creating optimal composting conditions (C:N, aeration, pH and humidity) and by adding some additives (wood cuttings, shavings, zeolites, peat etc.) into sewage sludge. In our study we analyse the experimental results on CH4, NH3, H2S and VOC emissions during sewage sludge composting process. For this experiment, centrifuge-dried sewage sludge from Vilnius City Municipal Sewage Treatment Plant were used. Used Ashen bark, oaken cuttings, aspen shavings, shredded deciduous tree branches. The composting process was performed in a compost site-simulating facilities.