Small wastewater treatment plants in mountain areas: combination of septic tank and biological filter

Abstract

Research work has been carried out for more than 20 years by Eparco and the University of Montpellier (France) on the application of biological wastewater treatment processes for small communities. This research has led to a new process which is particularly suitable for remote populations, taking into account several specificities such as as the seasonal fluctuations in the population, the accessibility of the site, the absence of a power supply on site, the reduced area of land available and the low maintenance. Thus, the process, which combines a septic tank operating under anaerobic conditions and a biological aerobic filter, is a solution for wastewater treatment in mountain areas. This paper presents the process and three full-scale applications in the region of the Alps.

Mathematical model for predicting sludge accumulation in septic tanks based on operational parameters: effect of hydraulic mixing

“…Figure 1 shows the comparison between the present model and the empirical models. The required values of b were estimated using the sludge accumulation rate reported in previous studies (Weibel et al 1955, Mancl 1984, Gray 1995, Heinss et al 1999, Kinsley et al 2005, Maunoir et al 2007). The present model shows a strong correlation to the sludge accumulation rate predicted by Bounds (1995) and Weibel et al (1955) with coefficient of determination (R 2 ) values of 0.97 and 0.88, respectively.…”

Analysis and Assessment of Biological Treatment Processes in a Small-Scale Wastewater Treatment Plant

“…Sludge age (of all three facilities) Indicator was above 30 24-hour periods, and temperature changed from 7.5 to 12.0ºC. As claimed in scientific literature, nitrifying bacteria are known to be very sensitive to low temperatures, and nitrification can be strongly inhibited by low temperatures [24][25][26][27]. It is stated that when low temperature (below 8°C and lower nitrification rate) was observed [27], it might indicated that January frosts negatively affected the nitrification process.…”

Biological Nitrogen Removal From Wastewater in Cold Period / Biologinis Azoto Junginių Šalinimas Iš Nuotekų Šaltuoju Laikotarpiu

“…Gali būti, kad sausio mėnesio šalčiai neigiamai veikė nitrifikacijos procesą. Mokslinėje literatūroje teigiama, kad Nitrifying bakterijos yra ypač jautrios temperatūros pokyčiams ir žema temperatūra stabdo nitrifikacijos procesą (Maunoir et al 2007;Almstrand et al 2011). Teigiama, kad, temperatūrai nukritus žemiau 8 o C, pastebėtas mažesnis nitrifikacijos greitis (Sajuni et al 2010).…”