Interdependence between total organic carbon content and heating value of sewage sludge samples

Sewage sludge from urban wastewater treatment plants come from different stages of wastewater treatment and are considered as waste, falling under the waste regulations. In order to reduce the negative environmental impacts, the removal of sewage sludge on landfill is considered as the last waste management option. One of the sludge management alternatives is to recover energy from the sewage sludge by incineration in waste incinerators or co-combustion in cement or thermal power plants. The use of sewage sludge as a source of renewable energy is an ecologically and economically efficient option, both in the EU and Romania sludge management strategy. Total organic carbon is a key environmental indicator for soil, sludge and sediment and a parameter for characterizing sludge for energy recovery. The paper presents the methodology for total organic carbon determination from acidified sludge samples by dry combustion, in an oxygen atmosphere using FlashEA 1112 Series Analyser. From the experimental laboratory researches the following aspects were highlighted: the interdependence between the total organic carbon content and the heating value of sludge samples, an important factor for energy recovery/elimination by incineration, co-combustion and utilization as secondary raw materials in cement plants.