Anaerobic biodegradability of carboxymethyloxysuccinate, a detergent builder

Abstract A range of thermal pretreatment conditions were used to evaluate the impact of high pressure thermal hydrolysis on the biodegradability of waste activated sludge (WAS) under aerobic and anaerobic conditions. It was found that pretreatment did not increase the overall extent to which WAS could be aerobically biodegraded. Thermal pretreatment transformed the biodegradable fraction of WAS (XH) to readily biodegradable chemical oxygen demand (COD) (SB) (16.5–34.6%) and slowly biodegradable COD (XB) (45.8–63.6%). The impact of pretreatment temperature and duration on WAS COD fractionation did not follow a consistent pattern as changes in COD solubilization did not correspond to the observed generation of SB through pretreatment. The pretreated WAS (PWAS) COD fractionations determined from aerobic respirometry were employed in anaerobic modeling and it was concluded that the aerobic and anaerobic biodegradability of PWAS differed. It was found that thermal pretreatment resulted in as much as 50% of the endogenous decay products becoming biodegradable in anaerobic digestion. Overall, it was concluded that the COD fractionation that was developed based upon the aerobic respirometry was valid. However, it was necessary to implement a first-order decay process that reflected changes in the anaerobic biodegradability of the endogenous products through pretreatment.

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Evaluation of anaerobic biodegradability of chemicals under sulfate and nitrate reducing conditions using digested sludge

Toxicological and Environmental Chemistry ◽

10.1080/02772249909358846 ◽

1999 ◽

Vol 73 (1-2) ◽

pp. 43-54

Author(s):

Kazumi Kawahara ◽

Yoshikuni Yakabe ◽

Tomohisa Ohide ◽

Kenji Kida

Keyword(s):

Digested Sludge ◽

Reducing Conditions ◽

Anaerobic Biodegradability

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Thermal hydrolysis of waste activated sludge at Hengelo Wastewater Treatment Plant, The Netherlands

Water Science & Technology ◽

10.2166/wst.2014.107 ◽

2014 ◽

Vol 70 (1) ◽

pp. 1-7 ◽

Cited By ~ 18

Author(s):

Mathijs Oosterhuis ◽

Davy Ringoot ◽

Alexander Hendriks ◽

Paul Roeleveld

Keyword(s):

Activated Sludge ◽

Treatment Plant ◽

Waste Activated Sludge ◽

Treatment Technique ◽

Thermal Hydrolysis ◽

Sludge Treatment ◽

Water Board ◽

Anaerobic Biodegradability ◽

Hydrolysis Process ◽

Hydrolysis Of

The thermal hydrolysis process (THP) is a sludge treatment technique which affects anaerobic biodegradability, viscosity and dewaterability of waste activated sludge (WAS). In 2011 a THP-pilot plant was operated, connected to laboratory-scale digesters, at the water board Regge en Dinkel and in cooperation with Cambi A.S. and MWH Global. Thermal hydrolysis of WAS resulted in a 62% greater volatile solids (VS) reduction compared to non-hydrolysed sludge. Furthermore, the pilot digesters could be operated at a 2.3 times higher solids loading rate compared to conventional sludge digesters. By application of thermal sludge hydrolysis, the overall efficiency of the sludge treatment process can be improved.

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