The difficulties and key points of sewage treatment mainly include the following aspects:
Water quality is complex and changeable: The composition and water quality of wastewater may vary from day to day. There are various pollutants such as organic matter, heavy metals, and microorganisms. The interactions between these pollutants and their impact on the treatment effect are difficult to predict, which brings great difficulties to wastewater treatment.
Efficient disposal and resource recovery: Wastewater treatment is not only about removing pollutants, but also about recycling resources. However, some valuable substances are present at low levels in wastewater, and the extraction and recycling process is complicated, which increases the treatment cost and technical difficulty1.
Safe discharge of treated wastewater: The effluent after wastewater treatment must meet the discharge standards to ensure safety for the environment and human health. However, some harmful substances in wastewater, such as difficult-to-degrade organic matter and heavy metal ions, have limited removal effects for conventional treatment processes, making wastewater treatment more difficult.
Governance concept lags behind: Some areas simply understand sewage treatment as collection, without clear management priorities and purposes, resulting in facilities that can only be seen but not used.
Single governance model: The sewage treatment facilities in some areas do not meet actual needs, resulting in the facilities being unable to be used normally.
Backward infrastructure：The sewage treatment facilities in many rural areas are rudimentary, and even lack basic treatment equipment, resulting in low treatment efficiency.
Difficult operation and maintenance：Due to backward facilities and high processing costs, many villages and towns are unable to afford daily maintenance and operating expenses, and the facilities are easily damaged or fail.
