Energy Consumption Of Wastewater Treatment Research Articles

Concepts and methodologies to minimize pollutant discharge for zero-emission production

The present study aims to present basic concepts to minimize the emissions from industrial production processes. Strategies and methodologies to analyze emissions from various production processes, to establish a so called negative flow sheet and to reduce the emissions from those processes by refining and/or replacing the present production process with an alternative process are discussed. Preliminary evaluation and management systems of the materials used in the production process based on characteristics such as microbial and physico-chemical treatabilities are proposed as well. The relationship between the removal efficiency of dissolved organic carbon in the five-days BOD test and that in a laboratory scale submerged biofilter with continuous operation is suggested to evaluate the biological removability of organic pollutants contained in wastewater. A novel concept to select the appropriate treatment process of an industrial wastewater based on properties such as the molecular size and biodegradability of the pollutants contained in that wastewater is also proposed. To give basic information for the minimization of energy consumption in wastewater treatment, various biological wastewater treatment processes are compared from the view point of power economy.

Concepts and methodologies to minimize pollutant discharge for zero-emission production

The present study aims to present basic concepts to minimize the emissions from industrial production processes. Strategies and methodologies to analyze emissions from various production processes, to establish a so called negative flow sheet and to reduce the emissions from those processes by refining and/or replacing the present production process with an alternative process are discussed. Preliminary evaluation and management systems of the materials used in the production process based on characteristics such as microbial and physico-chemical treatabilities are proposed as well. The relationship between the removal efficiency of dissolved organic carbon in the five-days BOD test and that in a laboratory scale submerged biofilter with continuous operation is suggested to evaluate the biological removability of organic pollutants contained in wastewater. A novel concept to select the appropriate treatment process of an industrial wastewater based on properties such as the molecular size and biodegradability of the pollutants contained in that wastewater is also proposed. To give basic information for the minimization of energy consumption in wastewater treatment, various biological wastewater treatment processes are compared from the view point of power economy.

Oxygen Supply Method Using Gas-Permeable Film for Wastewater Treatment

Gas-permeable film can separate air and water, and at the same time, let oxygen diffuse from the air to the water through the film. An oxygen supply method using this film was investigated for the purpose of reducing energy consumption for wastewater treatment. The oxygen transfer rate was measured for the cases with or without biofilm, which proved the high rate of oxygen transfer in the case with nitrifying biofilm which performed nitrification. When the Gas-permeable film with nitrifying biofilm was applied to the treatment of wastewater, denitrifying biofilm formed on the nitrifying biofilm, and simultaneous nitrification and denitrification occurred, resulting in the high rate of organic matter and T-N removal (7 gTOC/m2/d and 4 gT-N/m2/d, respectively). However, periodic sloughing of the denitrifying biofilm was needed to keep the oxygen transfer rate high. Energy consumption of the process using the film in the form of tubes was estimated to be less than 40% of that of the activated sludge process.