Which type of pond relies on fermentation, is odorous, and is primarily used for processing industrial wastes?

The correct answer is the anaerobic pond. Anaerobic ponds are designed specifically to facilitate the breakdown of organic material in the absence of oxygen. This process relies on fermentation, where microorganisms such as methanogens thrive and decompose organic matter, resulting in the production of biogas, which can include methane.

This type of pond is particularly effective for processing industrial wastes that are high in organic content since it can handle larger volumes of such waste and is often used in industries that produce significant quantities of organic effluents, such as food processing. One of the characteristic outcomes of anaerobic digestion is the production of odorous compounds, making anaerobic ponds often unpleasant in terms of smell.

In contrast, aerobic ponds require oxygen for microbial decomposition and do not typically result in the same level of odors as anaerobic ponds. Facultative ponds can support both aerobic and anaerobic processes but do not primarily utilize fermentation in the same manner as anaerobic ponds. Settled ponds, on the other hand, are primarily designed for sedimentation and do not actively process waste in the way anaerobic ponds do.