NOVELTY - A caffeine production wastewater is pH-adjusted to 4-8. Water is passed to oxidation pond, and hydrogen peroxide is added. Water is passed to floatation tank, maintained for 1-4 hours, and supplied to anaerobic sludge blanket. Processed water is supplied to biological contact oxidation pond, and maintained for 10-14 hours. Treated water is supplied to tank containing anaerobic active sludge, and maintained for 10-14 hours. Water is then passed to active sludge tank and sedimentation tank and maintained for 5-6 hours. Thus, caffeine production wastewater is processed.    USE - Processing of caffeine production wastewater.    ADVANTAGE - The caffeine production wastewater is efficiently processed.    DETAILED DESCRIPTION - A caffeine production wastewater is passed to a regulating tank for regulating pH to 4-8. The water is then passed to iron carbon-Fenton oxidation pond, and hydrogen peroxide is added in volume concentration of 0.1-0.5 L/m3. The pH value is regulated to 4-5. The concentration of bivalent ferrous ion is controlled to 50-200 mg/L. The obtained water is passed to floatation tank, maintained for 1-4 hours, and supplied to upflow anaerobic sludge blanket. The concentration of the anaerobic sludge in the reactor is 15-30 kg/m3. The anaerobic reduction potential is less than -300 mV. The processed water is supplied to biological contact oxidation pond with the combined filler (40-60%), and maintained for 10-14 hours. The oxygen dissolving content is 0.5-1 mg/L. The treated water is supplied to hydrolysis multifunctional tank containing anaerobic active sludge (10-20 kg/m3), and maintained for 10-14 hours. The oxygen dissolving content is 0.1-0.3 mg/L. The water is then passed to active sludge tank comprising chemical oxygen demand degradation bacteria or decoloring bacteria. The concentration of active sludge is 10-20 kg/m3. The oxygen dissolving content is 0.1-0.5 mg/L. The outlet water of active sludge tank is passed to secondary sedimentation tank and maintained for 5-6 hours. Thus, caffeine production wastewater is processed.