Impact of Sewage Sludge Dewatering on Economic and Environmental Balance of High Capacity Waste Water Treatment Plant

conference paper

English

There are still disputes amongst experts regarding burning sludge from communal sewage works. Two different ways of raw sludge treatment have been compared. One group prefers anaerobic digestion with a subsequent cogeneration of generated biogas, where the question of digested sludge needs to be dealt with. This is important especially if it does not meet the strict parameters for use in agriculture etc. The second group supports the burning of mixed raw sludge, where we can avoid the process of anaerobic digestion and also notably reduce waste which needs to be disposed. A key issue for the comparison of mass and energy flow of sludge management is the level of the attainable level of dewatering sludge. Results of dewatering anaerobic digestion sludge are available from applications since most sewage plants in the Czech Republic use digesters. The existing limited knowledge about dewatering mixed raw sludge have driven authors to make pilot dewatering tests targeted to establishment of an attainable level of dewatering mixed raw sludge. To get as close results as possible even anaerobic stabilized sludge was dewatered and various other data were collected to obtain comprehensive data set for energy balance of sludge management calculation Measured data have been used to calculate energy balance of a number of different sludge managements. The results of three options are presented in this work: I. option - anaerobic digestion of mixed raw sludge with subsequent cogeneration of obtained biogas, II. option - burning mixed raw sludge utilizing energy contained in flue gases, III. option - burning digested sludge utilizing energy contained in biogas and flue gases. Since the economic aspect is just as important as the energy one, the study also includes a simple economic comparisons of the above options.

sewage sludge, heat balance

HOUDKOVÁ, L.; BORÁŇ, J.; UCEKAJ, V.; STEHLÍK, P.

2006

27. 8. 2006

Process Engineering Publisher

Praha

80-86059-45-6

CD-ROM of Full Texts

1

H2.8

12