Most opinions indicate that anaerobic fermentation is very sensitive to operate and difficult to control. However, it should be noted that most of the experience with anaerobic systems has been gained in sewage treatment facilities. Sewage sludge often contains toxic materials such as heavy metals from industrial wastes, which may be part of the reason anaerobic digestion of these sludges is unreliable. Agricultural wastes would probably not pose the toxicity problems met in sewage sludge. Home A remarkable feature of this system is that its cost is relatively low.
Raw materials cost nothing and their abundance is staggering.
Furthermore, the by-product can be used as valuable fertilizer sludge. There are many advantages and disadvantages with an on-site anaerobic digestion facility, but the main criterion invariably is economic feasibility. Already farms and dairies are feeling a pinch with increases in feed and maintenance costs. This state of affairs could eventually force the smaller dairies out of business. The proposed bioconversion facility must be designed to keep farms and dairies in business without encumbering too large a capital investment.