Project Overview

This project is the construction of kitchen waste treatment and resource utilization facilities in Qingchuan County, with a designed treatment capacity of 15 m³/d. The main process adopts a combined route of "Collection Tank + Anaerobic Reactor + Integrated Biochemical Treatment System." Anaerobic digestion acts as the core carbon-reduction unit, which is followed by advanced treatment by the integrated biochemical system to realize compliant effluent discharge.

This process route fully considers the characteristics of kitchen wastewater, including high organic concentration and favorable biodegradability, and balances operational stability and cost-effectiveness. The anaerobic phase can efficiently reduce organic loading and recover biogas energy, whereas the aerobic phase further removes residual pollutants. The overall process is concise and compact, convenient for operation and maintenance, and satisfies the practical demands of small- and medium-scale kitchen wastewater treatment.

Designed Treatment Capacity: 15 m³/d

Key Technical Challenges

The primary challenge lies in the extremely high organic concentration and abundant oil and grease content. The oils and fats exist in multiple forms—dissolved, emulsified, and suspended—which can easily lead to pipeline blockages, reduced anaerobic sludge activity, and excessive scum production, posing continuous challenges to the oil removal pretreatment and the stable operation of the anaerobic reactor. At the same time, the wastewater contains relatively high concentrations of nitrogen and phosphorus, making it difficult to achieve simultaneous efficient nitrogen and phosphorus removal through anaerobic + conventional aerobic treatment alone. Therefore, precise control of the C/N ratio and recirculation ratio during operation is required.

Another significant challenge is the rapid acidification of the wastewater and the proliferation of harmful microorganisms. Due to the high content of easily degradable substrates such as proteins and starch, the wastewater is highly susceptible to rapid acidification during collection and storage, leading to a drop in pH. This inhibits the activity of methanogens, adversely affecting the biogas yield and operational stability of the anaerobic reactor.

Process Flow

Kitchen wastewater → Equalization Tank → Anaerobic Reactor → Facultative Tank → Biological Contact Oxidation Tank → MBR Tank → Coagulation & Clarification Tank → Clear Water Tank → Compliant Discharge