Anaerobic treatment systems such as UASB do not require an energy consuming aeration system and can be constructed much simpler than aerobic treatments. They convert the organic matter into biogas, which can be recovered. The nutrient-rich effluent can be used for agricultural irrigation . Sludge, even is partily stabilised (mineralised) and can be used as an organic soil fertiliser after composting or drying.
UASB reactors can treat all type of hyigh-strenght wastewater. It can be used at large-scale (e.g. agro-industrail wastes) or as decentralised treatment systems for domestic wastewaters; yet domestic treatment is still relatively new and not always successful as domestic wastewater generally lower strength.
