Rich in organic and nitrogen-based matter, animal husbandry waste is subject to a three-step process including solid–liquid separation, anaerobic digestion and aerobic bioremediation in current practice. Aerobic bioremediation requires aeration, an electricity-demanding procedure. The waste is usually discharged into waterways for cost reduction at the price of pollution, or contains residual ammonia from the three-step processing equipment which also inflicts extra oxygen demand that prevents a decisive solution to waterway pollution. For business owners, the complicated application procedures dissuade them from maintaining compliance, resulting in significant waterway pollution.
Factors such as the highest fine for violating the effluent standards or arbitrary discharging upscaled from NT$ 120,000–NT$ 600,000 to NT$ 600,000–NT$ 20,000,000 in the amended “Water Pollution Control Act” announced on February 4, 2015, the collection of the animal husbandry water pollution control fee starting from 2017, and the increasing costs of waste treatment facilitated the recycling and reuse system of animal husbandry wastes. Unlike the conventional method of processing and discharge, biogas, slurry and residues from anaerobic digestion can be reused in this innovative model.