Anaerobic Tower | Internal Circulation Anaerobic Tower | Hydrolysis-Acidification Tower

Working Principle Take the IC internal circulation anaerobic tower as an example. Wastewater enters from the bottom and mixes with granular sludge. Biogas rising from the gas production zone lifts the sludge-water mixture up through the riser into the gas-liquid separator at the top. The biogas is released, and the sludge-water mixture falls back down, creating an internal circulation. This loop expands the sludge bed and brings organics into better contact with microorganisms. In a hydrolysis-acidification tower, acid-producing bacteria break complex organics into organic acids and alcohols without producing methane, and retention time is shorter. A full anaerobic tower then uses methanogens to convert those acids into biogas and carbon dioxide. Application Fields 1.Alcohol wastewater: high-strength organic wastewater well suited to anaerobic tower treatment, with high COD removal. 2.Pharmaceutical wastewater: containing antibiotics or hard-to-degrade compounds; an internal circulation anaerobic tower can break ring structures and molecular chains before aerobic treatment. 3.Landfill leachate: high ammonia and organic concentration; a hydrolysis-acidification tower can improve biodegradability. 4.Livestock wastewater: high suspended solids and COD; an anaerobic tower cuts most of the organic load and recovers biogas. FAQ Q1: What volumetric loading rate can an internal circulation anaerobic tower typically handle? A: IC towers typically run at 15–30 kg COD/(m³·d), and can hit around 40 under favorable conditions. The internal circulation keeps the granular sludge expanded and mass transfer efficient, so it's several times higher than a standard UASB. But if influent suspended solids are too high, sludge will wash out. Q2: What's the difference between a hydrolysis-acidification tower and a full anaerobic tower? A: A hydrolysis-acidification tower only breaks large molecules into smaller ones and doesn't produce biogas. Retention time is short, and the main goal is improving biodegradability. A full anaerobic tower goes further with methanogens, produces biogas, needs longer retention time, and achieves higher COD removal. The former is often used as pre-treatment, the latter as the main treatment step. Q3: What does the three-phase separator inside an anaerobic tower do? A: It separates biogas, sludge, and effluent. Biogas exits from the top, sludge settles back into the reaction zone, and effluent overflows out. How well it separates directly affects effluent suspended solids and how much sludge is retained—it's a key component of an anaerobic tower.