Mechanical sludge disintegration for the production of carbon source for biological nutrient removal

Abstract

The primary driver for a successful biological nutrient removal is the availability of suitable carbon source, mainly in the form of volatile fatty acids (VFA). Several methods have been examined to increase the amount of VFAs in wastewater. This study investigates the mechanism of mechanical disintegration of thickened surplus activated sludge by a deflaker technology for the production of organic matter. This equipment was able to increase the soluble carbon in terms of VFA and soluble chemical oxygen demand (SCOD) with the maximum concentration to be around 850 and 6530 mgl(-1), for VFA and SCOD, respectively. The particle size was reduced from 65.5 to 9.3 microm after 15 min of disintegration with the simultaneous release of proteins (1550 mgl(-1)) and carbohydrates (307 mgl(-1)) indicating floc disruption and breakage. High performance size exclusion chromatography investigated the disintegrated sludge and confirmed that the deflaker was able to destroy the flocs releasing polymeric substances that are typically found outside of cells. When long disintegration times were applied (>or=10 min or >or=9000 kJkg(-1)TS of specific energy) smaller molecular size materials were released to the liquid phase, which are considered to be found inside the cells indicating cell lysis.

Simultaneous denitrification and denitrifying phosphorus removal in a full-scale anoxic–oxic process without internal recycle treating low strength wastewater

“…Park et al (2011b) considered that ozonolysate of excess sludge as a carbon source could be enhanced for phosphorus removal with a C/P ratio of 42-57 using a modified intermittently decanted extended aeration process. However, the addition of disintegrated sludge resulted in low C/P ratio of less than 13.6 that would slow the process (Kampas et al 2007). …”

“…Several methods have been examined to enhance nitrogen removal, including internal carbon source addition (Biradar et al 2010;Kampas et al 2007;Park et al 2011a) and external carbon source addition (Gong et al 2013;Modin et al 2007;Quan et al 2005). However, carbon source addition could increase operation cost and carbon footprint.…”

Influence of Microwave Pre-Treatment on the Digestion and Higienisation of Waste Activated Sludge/Wpływ Dezintegracji Mikrofalowej Na Proces Fermentacji Oraz Higienizacji Nadmiernych Osadów Ściekowych

“…An increased concentration of organic and inorganic substances in post-digestion waters undergoing pre-treatment influenced also the sludge susceptibility to dewatering in a negative way (Table 5). Such liquors exhibited a negative impact on the wastewater treatment processes, especially the denitrification [34,35]. Nowadays, the post-digestion liquors are more and more frequently treated separately with the application of biological as well as physical and chemical methods.…”

Thermal conductivity characteristics of dewatered sewage sludge by thermal hydrolysis reaction

“…Sewage sludge is rich in organic carbon, and so it may be utilized as a cheap but valuable resource for the production of volatile fatty acids (VFAs). It is widely applied as a means to convert organic waste into substrates for many bioprocesses of nutrient removal of wastewater (Bougrier et al, 2007(Bougrier et al, , 2008; Kampas et al, 2007) and biopolymer production (Chua et al, 2003). It has also been used to increase methane production by increasing digestion efficiency in an anaerobic digestion tank (Bougrier et al, 2006;Keymer et al, 2013).…”