Co-digestion of sewage sludge and wood fly ash

• This study uses a new approach for the recycling of plant nutrients by co-digesting sewage sludgewith fly ash from a wood combustion. Sewage sludge and fly ash both are enriched with nutrientsof the wastewater resp. wood, which makes these products an enhanced source for recycledfertilizers. The effects of the ash addition to the anaerobic digestion are studied in several labscale experiments including effects on the gas production and microbial activity. Following that,the fertilizing qualities of the digestate are evaluated by plant growth experiments. The resultsshow that the fertilizing qualities of the digested sludge were improved by the ash addition.Next to this, gas production results show that the methane production was not affected by theash addition, while the total gas release was reduced. The sulphur addition by the ashstimulated sulphate reducing bacteria. The sulphate reducing bacteria did not markedly inhibitthe methanogens.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Naturresursteknik -- Annan naturresursteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Environmental Engineering -- Other Environmental Engineering (hsv//eng)

TEKNIK OCH TEKNOLOGIER  -- Miljöbioteknik -- Annan miljöbioteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Environmental Biotechnology -- Other Environmental Biotechnology (hsv//eng)

Keyword

Anaerobic digestion

sewage sludge

ash

co-digestion

nutrient recycling

Avfallsteknik

Waste Science and Technology

Publication and Content Type

ref (subject category)

art (subject category)