Economic Analysis of Wastewater Biological Treatment Technology

7.
3.
1 Economic analysis of wastewater biological treatment technology

The analysis of economic performance involves operating costs, floor space, investment in treatment processes, etc.
In addition, plant sites, different climatic conditions and regions are also economic factors that affect different processes
.

However, it is relatively difficult to discuss costs that vary with plant sites, regions, and climatic conditions.

The selection of sewage treatment process is the key to the construction of sewage treatment plant.
It not only affects the treatment effect of the treatment plant, but also affects the capital investment of the entire treatment project, the level of operating costs, the reliability of the operation of the treatment process, and the complexity of the management operation
.

Therefore, the appropriate treatment process must be selected according to the actual conditions of the local climate, temperature, geography, meteorology, economy, as well as the amount and quality of sewage

The operating cost of a sewage treatment plant consists of energy consumption, maintenance, labor, sludge and waste disposal fees, pharmaceutical fees, management fees, and sewage effluent discharge fees
.

For urban sewage treatment, the operating costs are mainly in two aspects: one is the power consumption of the aeration tank blower room, which generally accounts for 50% to 60% of the total energy consumption cost, which is mainly related to the water quality and effluent standards; the second is the lift pump House electricity consumption generally accounts for 20% to 30% of the total energy consumption

From October 2005 to May 2006, the Key Laboratory of the Ministry of Education for the Ecological Environment of the Three Gorges Reservoir Area of ​​Chongqing University selected 38 municipal sewage treatment plants nationwide that adopted typical processes (oxidation ditch, A2/O, SBR, etc.
).
Focus on investigating the technical and economic performance of different biological treatment processes used in various sewage plants, and focusing on the technical and economic evaluation of the oxidation ditch process based on the collected data
.

The processes used in the 38 sample surveys of sewage treatment plants in the 8 provinces and 3 municipalities involved can be classified into 4 categories: oxidation ditch (accounting for 34.

Table 7-5 Technical evaluation statistical results of sewage treatment plants

Table 7-6 Economic evaluation results of various treatment processes

Note: The energy consumption analysis is based on the statistical data of 5 oxidation ditch wastewater treatment plants; the ton of water treatment cost and COD treatment cost are based on the statistical analysis of 11 wastewater treatment plants with detailed operating data among the 38 wastewater treatment plants
.

Based on the above analysis, the oxidation ditch process is the most used process in 38 representative urban sewage treatment plants
.

The technical and economic evaluation results show that the oxidation ditch has good performance in removing common pollutants, nitrogen and phosphorus removal, operation management, and sludge stabilization, and its economic indicators such as land occupation, construction investment, and operating costs are also good