Physicochemical properties of biochar derived from anaerobic
digestion effluent from cheese factory drainage.
Anaerobic digestion technology is a waste
treatment process. It can successfully treat the organic wastes from many
industries such as municipal sludge, industrial wastewater, agricultural
waste. Anaerobic digestion effluent (ADE) which is residue of anaerobic
digestion process contain sufficient amounts of plant nutrition such as
nitrogen, phosphorus and potassium. Fertilizer effects of liquid part of
ADE have been shown in previous studies. However, usage of solid part of ADE
has not been established. Generally, residues
obtained from anaerobic digestion are applied as compost to soils directly. But increasing
concerns regarding the contamination potential of toxic substances have
necessitated alternative methods. Pyrolysis of the solid part of ADE to
produce biochar has been proposed as a beneficial product. Therefore, the
objective of this study was to investigate the physicochemical properties of
biochars derived from anaerobic digestion effluent from cheese factory
drainage.
The ADE used in this study was separated
for liquid and solid parts. The solid part was pyrolysed at 350, 550, and 800oC
(ADE350, ADE550, and ADE800, respectively).
The surface area of the biochars were determined by
nitrogen BET. The pH, total carbon, total nitrogen, total phosphorus, ammonium, nitrite, and citric acid-extractable phosphorus of the
biochars were analyzed.
The biochar yield rates of ADE350, ADE550, and ADE800 were 45%, 27.5% and 25.4%
of the initial dry weight of the solid ADE, respectively. As pyrolysis temperature increased ash content increased, however
volatile matter and fixed carbon contents decreased. The
results of this study showed that biochar produced at lowest temperature had
the lowest yield rate and highest volatile matter content, as seen in other
studies.