Help please. I have been trying to determine the calorific value of Faecal Sludge by using bomb calorimeter. The temperature should rise for sometime before starting to fall. But in my case it keeps on rising. Has anybody faced this problem before? Can anyone give me any suggestions?

Thanks a lot Chris for the suggestions.

Thanks a lot BJ for your suggestions and attachments.

I'm really sorry for the late response, I was busy with my exams.

Hi Progga,

We recently published a paper where we measured the calorific value of chars made from fecal sludge, and used the ASTM method D2015 (Standard Test Method for Gross Calorific Value of Solid Fuel by the Adiabatic Bomb Calorimeter). The ASTM method is here: law.resource.org/pub/us/cfr/ibr/003/astm.d2015.1996.pdf

I've also attached the paper so that you can take a look at the methods section.

To answer your question about time limit for conducting the experiment - if you're collecting relatively fresh sludge, I would recommend refrigerating or freezing it until you're ready to analyze it. We have seen fresh sludges degrading pretty rapidly when not stored at cool temperatures, and have noticed that the energy content can decrease significantly as the material continues to degrade. So, for practical use in your project, if you're taking multiple measurements of one type of fecal sludge, either do them all in the same day or two, or make sure you keep them frozen or refrigerated between runs in the calorimeter.

Good luck!
BJ

Greetings
I suggest you use the ASTM technique for the calorific value.

In addition determine (1) the dry solids mass at 105 Deg C (and thus moisture content); (2) the volatile solids content by igniting in a muffle furnace at about 500 Deg C, this will also yield the ash content; (3) the soluble ash content, by washing out the soluble components.

You may also wish to measure the charring temperature and to produce bio char
The opportunities for biochar are: yield, ash content, surface area.

Chris

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Hi joeturner, thanks a lot. But I have already read this paper, the procedure is not described here and they have said that they determined calorific value, water content and total solids according to 'standard methods(1995)'. I couldn't find any procedure described in the chapter 2(faecal sludge quantification, characterization and treatment objectives) of standard methods(1995) and I couldn't find the complete standard methods(1995) anywhere either.
And about other parameters, as my work is in small scale I may not have the chance to determine other parameters described there for 'dried' sludge apart from COD. So I need some suggestions on that.

Hi Progga, I don't know, but it looks like this recent paper used the bomb calorimeter so maybe their method will tell you? www.eawag.ch/forschung/sandec/publikatio...dl/muspratt_2014.pdf

Hi I am a student of civil engineering majoring in environmental engineering in Bangladesh university of engineering and technology(BUET). My undergraduate thesis topic is on faecal sludge management. I want to determine the calorific value of faecal sludge using bomb calorimeter. In the laboratory they use the bomb calorimeter to determine gross calorific value of coke and coal according to ASTM standard methods. Should I follow this standard method or is there any specific laboratory standard for faecal sludge? Can anyone tell me the time limit within which I have to conduct the experiment? I want to determine other parameters on 'dried' faecal sludge too, so can anyone suggest me which parameters are applicable for dried faecal sludge beside COD?