Assessment of enhanced biological phosphorus removal process inhibition
- PDF / 1,200,986 Bytes
- 10 Pages / 595.276 x 790.866 pts Page_size
- 93 Downloads / 225 Views
Assessment of enhanced biological phosphorus removal process inhibition Kati Klein1 · Anni Mandel1 · Hegne Lilleoja1 · Siim Salmar1 · Taavo Tenno1 Received: 11 May 2020 / Accepted: 28 July 2020 © Springer Nature Switzerland AG 2020
Abstract Wastewater in industrial regions frequently contains substances which are potentially inhibitory to activated sludge treatment processes. Enhanced biological phosphorus removal (EBPR) is vulnerable to process inhibition mostly because of the location at the beginning of the treatment process and complex characteristics of influent. Much knowledge has been developed on the EBPR process; nonetheless, methods used for estimation of the process inhibition vary largely. There is no easily applicable and reliable method available for rapid determination of inhibition of the EBPR process. In this study, a method for evaluation of inhibition on the EBPR process was developed and controlled. In contrast with previous research, a fresh non-acclimated inoculum was used to enhance the possibility to predict the impact for wastewater treatment plant. The efficiency of the process was evaluated based on the values of orthophosphate release and uptake, synthesis and consumption of polyhydroxyalkanoates. 3,5-dichlorophenol (3,5-DCP) was used as a model inhibitory compound. It was found that the EBPR inhibition tests using a non-acclimated sludge need wastewater as the organic carbon source. Furthermore, the length of aerobic period substantially influenced the inhibition test results— achieved maximum inhibitory concentration (IC50) values were 2.4 times higher when aerobic phase was 6 h instead of 1.5 h. Consequently, extended aeration period was suggested to diminish the inhibition effect. Finally, the impact of the 3,5-DCP on different activated sludge treatment process using respective standard methods was tested and compared. It was found that EBPR process was similarly to the nitrification a sensitive activated sludge process. Keywords Activated sludge · Industrial wastewater · Inhibition test · Polyhydroxyalkanoates (PHA) · Polyphosphate accumulating organism (PAO)
1 Introduction Anthropogenic release of phosphorus (P) is an environmental risk since it is a key driver of eutrophication. On the other hand, demand for P as a fertilizer is globally increasing as its reserves are decreasing. In enhanced biological phosphorus removal (EBPR) process, P is removed from wastewater and accumulated to waste activated sludge (WAS) by polyphosphate accumulating microorganisms (PAOs). Efficiently treated P-enriched biomass can be further used as a fertilizer directly or indirectly. Thus, it is essential to achieve and maintain efficient biological
phosphorus removal process in wastewater treatment plants (WWTPs). Selectivity of PAOs is achieved by alternating anaerobic and aerobic conditions or application of the aerobic/ extended-idle (AEI) regime [1]. In conventional EBPR process, PAOs consume energy gained from hydrolysis of polyphosphate and glycogen degradation to take up volatile fatty a
Data Loading...
