Hrvatske vode, Vol. 25 No. 102, 2017.
Preliminary communication
Analysis of wastewater quality indicators in relation to wastewater temperature and precipitation by means of the RAPS method
Bojan Đurin
; Faculty of Geotechnical Engineering, University of Zagreb, Varaždin, Croatia
Anita Ptiček Siročić
; Faculty of Geotechnical Engineering, University of Zagreb, Varaždin, Croatia
Anamarija Muhar
; Faculty of Geotechnical Engineering, University of Zagreb, Varaždin, Croatia
Abstract
The RAPS method (Rescaled Adjusted Partial Sums) was implemented to analysing input and output indictors of the Čakovec wastewater treatment plant during June, July and August 2015. The paper’s aim was to establish a relation of the precipitation volume and daily mean air temperature with the values of input and output time series related to chemical oxygen demand (COD), 5-day biological oxygen demand (BOD5) and suspended solids at the WWTP. The RAPS method was applied to precipitation volume time series, but was not higly efficient due to large osciallations of precipita¬iton volumes in the observed period. A further analysis was based excluisvely on the comparison of the input and output values of COD, BOD5 and suspended solids with daily mean air temperature. The results show that the input series contain more pronounced subseries in terms of their mean value and the trends of increasing or decreasing values. In comparison with the input subseries, the output subseries do not oscillate in such measure since they are related to wastewater output quality. A visible decrease in indicator outlet values confirms a high quality treatment of input wastewater.
Keywords
wastewater treatment plant; RAPS; precipitation; air temperature; indicators; wastewater quality
Hrčak ID:
192553
URI
Publication date:
27.12.2017.
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