Congruence in the performance of model nitrifying activated sludge plants located in Germany, Scotland and Spain

Christofi, Nick; Aspichueta, Elena; Dalzell, David; De la Sota, Alejandro; Etxebarria, Javier; Fernandes, Teresa; Gutierrez, Monica; Morton, John; Obst, Ursula; Schmellenkamp, Peter

Abstract

A laboratory model nitrifying activated sludge plant treating OECD synthetic sewage was designed and constructed by each of three laboratories in Germany, Scotland and Spain in order to produce a sludge inoculum for 5 rapid toxicity bioassays. The plants were run for 3 years and produced sludge for the microbially based bioassays Vibrio fischeri bioluminescence, ATP luminescence and respiration, and, nitrification and enzyme inhibition. Although the initial sludge inoculum for the plants differed, as did some of the running conditions such as temperature regime, the sludge produced within the different countries had similar characteristics with respect to sludge age, total suspended solids and volatile suspended solids. Nitrification was generally maintained over the 3-year period although there were occasions when the process was inconsistent. Nitrification recovery was afforded by reseeding with a nitrifying sludge from a local wastewater treatment works (WWTW) or imposition of starvation conditions for a period of time.

The sludge produced was used to carry out toxicity testing and results compared well with those using sludge from a WWTW. Overall, the use of sludge generated in the laboratory could be used for toxicity testing negating the need to resort to the use of natural WWTW sludge, which may contain a range of toxic substances due to uncontrolled industrial and domestic inputs and an unbalanced microbial consortium.

• Journal Article Type: Article
• Publication Date: 2003-01
• Deposit Date: Jul 14, 2008
• Print ISSN: 0043-1354
• Publisher: IWA Publishing
• Peer Reviewed: Peer Reviewed
• Volume: 37
• Issue: 1
• Pages: 177-187
• DOI: https://doi.org/10.1016/s0043-1354%2802%2900119-7
• Keywords: Laboratory tests; Sewage plant models; Nitrifying active sludge; Scotland; Spain; Germany; Microbial bioassays; Wastewater Treament Works control sludge; Comparisons
• Public URL: http://researchrepository.napier.ac.uk/id/eprint/1720
• Publisher URL: http://dx.doi.org/10.1016/S0043-1354(02)00119-7