For those interested in the Ironbridge Sludge Supercritical Water Oxidation project,, the following is a link to the agreement with the City Of Orlando for the demonstration scale project. Its an interesting agreement in that it tries to get around the 'valley of death' syndrome for new technologies by providing an incentive for the City to host and support the project.

 http://orlapp1.ci.orlando.fl.us/asv/paperlessagenda.nsf/6acecff5f30ecb0d85256bd0005abae0/4f28ce12546807bd852572cf003d5d49?OpenDocument

In general Municipalities appear to be getting more creative in how they engage with sludge to energy projects.  

Perry Brake and James Royer have got it right on the nailhead on this.

Running additional replicates will not change anything. You already run duplicates every ten samples anyway and if these show similar results you can assume that the rest of your analyses have similar precision.

Remember the reason why we run multiple dilutions: to make sure we get at least one bottle with acceptable result. We have found that some sampling sites, such as our plant primary, are so stable that we only run 2 bottles.

Other sampling points like our effluent are consistently clean and we theoretically could run just one 300 mls bottle all the time. However, we once had an plant upset incident a week after we changed to setting up three 300mls for the effluent. The plant was then unable to report a BOD value except as a >6 mg/l, so we immediately went back to setting up 75, 150 and 300 and will stay that way.

Whatever differences there are between your lab and the other lab are probably systemic and due to the different way the test is run or different reagents and/or seeds.

Luis Manriquez

Lime stabilized sludge has been land applied in Vermont.

I suggest you contact the VT Agency of Environmental Conservation in Waterbury VT for their experience.

Concord NH also land applies lime stabilized sludge.

We have an industry that wishes to discharge a waste containing Polyethylene Glycol (PEG) which is used in the process of cutting silicon wafers.  It has a COD in the millions (!!) but a BOD of only around 50,000 mg/l, so it does not seem to be very amenable to aerobic treatment.  Incidentally, WW plants have been receiving PEGs for quite a while as certain of them are used in the stuff you get to drink the night before a colonoscopy!!!  Whatever, my question has to do with whether anyone has determined in PEG's are treatable by ANaerobic digestion.  AND...how would you test anaerobic treatability??

PS:  don't confuse PEGs with antifreezes.  They are related to the propylene glycol in antifreeze but are much larger molecules with sizes from 400 to 1000 daltons.

This anaerobic digester operation utilizes continuous mixing (to support foam suppression).  Since continuous mixing began, sludge does not separate to form supernatant in a storage tank, as it had prior to continual mixing. 

Digester %TS concentration is about 2.3 mg/L. 

Has anyone had or heard of a similar experience with treated anaerobic sludge? 

Hi all

we have filtered backwash sludge that is dewatered by centrifuge with the addition of polyelectrolyte. Sludge is expected to be 10-20% solids so we want to use progressive cavity pumps to send it to the containers.

Does anybody have any experience of pumping such sludge ? It is highly gelatinous and we are affraid of blockage

Regards

Doctor Sewage

I've started a new LinkedIn site for those interested.  Go to:

Biosolids and Residuals Management
http://www.linkedin.com/e/vgh/2595370/

and apply to join the group.

I am concerned about the paucity of discussion here, however.