TRENDS IN ANAEROBIC SYSTEMS
Anaerobic systems are well suited to the treatment
of slaughterhouse wastewater. They achieve a high
degree of BOD removal at a significantly lower cost
than comparable aerobic systems and generate a
smaller quantity of highly stabilised, and more easily
dewatered, sludge. Furthermore, the methane-rich
gas which is generated can be captured for use as a
fuel.
In most countries, the anaerobic pond has been
used to achieve a high reduction in BOD, oil andgrease and suspended solids concentrations from the
primary-treated slaughterhouse wastewater prior to
subsequent aerobic treatment. Unfortunately, the
propensity for odour generation from anaerobic
ponds has threatened their continued use in many
areas. Consequently, new developments in anaerobic
technology during the last 15 years are of considerable
interest. These can be divided into two groups:
(i) covered anaerobic ponds,
(ii) high rate anaerobic systems.