Since 1984, EERL has researched various treatment technologies to manage environmental pollution efficiently. Fundamental and practical researches include water, wastewater, and solid waste treatment by biological approaches. Our main research fields are anaerobic, aerobic, and membrane biotechnology. In the field of anaerobic treatment, novel process for methane/hydrogen production and wastewater/solid waste treatment have been developed. In other areas, new technologies such as nitrogen and phosphorous removal, submerged membrane bioreactor, and process automation are studied. Specifically, development of novel anaerobic treatment technology for clean bio-energy production, research on the optimal operation condition for nutrient removal using the UMBR (Upflow Multi-Layered Bioreactor), development of a hybrid-type vertical MBR (Membrane Bioreactor) process with thermophillically acidified sludge as a carbon source, and a high-rate anaerobic digestion system for fat-rich wastewater have been undertaken.