Strategies of improvement ofUASB reactor operation

The Upflow Anaerobic Sludge Blanket (UASB) reactor is one from the most widely used anaerobic technology to remove organic matter from wastewater, popular mostly in countries with warm climate but use all over the world. UASB reactor have mainly advantages: during organic matter removal biogas is produced, low energy consumption and simplicity of work. This study evaluates the effect of hydraulic retention time (HRT) on CODtot removal and attempts to optimize the UASB reactor work on line 4 in Hammarby Sjöstadsverk research station in Stockholm. During the four-month study performed analyzes: CODtot, CODdis, CODsus as a measure of the amount of organic matter, pH, alkalinity, NH4, temperature of inlet and outlet wastewater. Analysis was focus on UASB reactor 1 and inlet to next step of wastewater treatment- IFAS reactor. Studies were divided into two periods during which HRT was performed. In first period (31.01-07.05.2017) UASB reactors worked at HRT of 3.33h and in the second period (08.05-16.06.2017) UASB reactor 1 worked at HRT of 4.04 h and UASB reactor 2 worked at HRT of 2.99 h. The best result was achieved during the first period and the CODtot removal efficiency in reactor 1 was 73.75% with ORL 2,3 kg CODtot/m 3*d