The model of the entire Domžale-Kamnik wastewater treatment plant (WWTP) has been built by using GPS-X software. The model includes both the water line and the sludge line and shows a relatively good agreement with the real plant daily average measurements. This model is in Domžale-Kamnik WWTP used for running various simulation studies to improve the operation of the plant. The model has been used for studying the possibilities of how to reduce the impact of the sludge line on the water line in Domžale-Kamnik WWTP. Simulation results show that by properly increasing the digested sludge flow-rate to dewatering, the amount of the sludge and ammonia that are back-cycled from the sludge line to the water line are significantly reduced, whereas the amount of the dehydrated sludge, which is disposed to the landfills and the amount of the biogas produced remain almost the same. Testing in the Domžale-Kamnik WWTP shows that by increasing the flow rate to dewatering unit reduces the amount of the sludge, which is returned to the water line, which reduces the plant load and consequently operation costs of the plant.
F.08 Development and manufacture of a prototype
COBISS.SI-ID: 26004775Operation of the conceptual design of a sequencing batch reactor (SBR) for upgrading the Domžale-Kamnik WWTP with the third level of treatment was verified. Verification of the upgrading was performed with a mathematical model using the GPS-X software. It was found out that larger volumes of the reaction tanks, from those suggested in the conceptual design of SBR, have to be used for upgrading the plant. Verification of the Domžale-Kamnik WWTP upgrading is very important since upgrading of the plant represents an investment cost of more than 10 million EUR.
F.17 Transfer of existing technologies, know-how, methods and procedures into practice
COBISS.SI-ID: 25308455The model of the water line in Domžale-Kamnik wastewater treatment plant (WWTP) was designed, with the aim to determine whether it would be possible to reduce the concentration of nitrogen compounds in the effluent only with smaller changes in the plant. The model shows a relatively good agreement with the daily average measurements. Lower agreement in measurements of ammonia and total nitrogen is probably due to bulking and denitrification in the secondary settlers which the model does not take into account. The model was used to test how the plant works at various bypass flow rates, oxygen concentrations in the aeration tanks, waste sludge flow rates from secondary settlers and recycle flow rates from the second to the first aeration stage. It was found out that by introducing the bypass of the first biological stage, internal recycle from the second to the first stage and by reducing the oxygen concentrations in the aeration reactors it is possible to reduce the effluent total nitrogen concentrations for more than 20 %. Testing on the Domžale-Kamnik WWTP shows that the partial bypass of the first biological stage improves the quality of the biomass in the second biological stage and consequently the effluent quality.
F.17 Transfer of existing technologies, know-how, methods and procedures into practice
COBISS.SI-ID: 2049019Model of the sludge treatment process in Domžale-Kamnik WWTP was designed. With this model a relatively good agreement in steady-state operation is achieved in comparison with the measurements. Larger model deviation from the measurements was obtained only in the concentration of the suspended solids in the sludge overflow from the digestion tanks because the real digestion tanks are not completely mixed. The designed model is used to perform several simulation scenarios. Simulations show that the volumes of the sludge treatment tanks are large enough to maximize the gas production even at the maximum sludge flow rate. The gas production can be improved by increasing the sludge temperature to 55 oC. Sludge treatment can be also improved by optimizing the ratio between the digested sludge pumped to the dewatering process and the sludge overflow returned back to the water line.
F.17 Transfer of existing technologies, know-how, methods and procedures into practice
COBISS.SI-ID: 24881959