The Pakistan Hospital Sewage Treatment Project is a key initiative aimed at enhancing the environmental protection standards of local medical facilities and safeguarding public health safety. The project targets the treatment of medical and domestic wastewater generated by a certain hospital, employing advanced AO (Anaerobic-Oxic) process and integrated sewage treatment equipment to achieve efficient and stable treatment of 90 tons of sewage per day, meeting environmental protection standards and setting an example for hospital sewage treatment in Pakistan.
1. Treatment Capacity: The project's treatment capacity is 90 tons/day, and the AO process can accommodate this scale of treatment demand.
The raw water for this project is medical and domestic wastewater, primarily originating from the hospital's clinics, laboratories, wards, laundry rooms, operating rooms, as well as administrative departments and the living areas of medical staff. These wastewaters have complex compositions, containing a large amount of refractory organic pollutants, pathogens, viruses, and heavy metals. Among them, the residual drugs, disinfectants, and by-products in medical wastewater have potential toxicity to the environment and biological organisms. Therefore, the treatment of such wastewater requires efficient and comprehensive process technologies.
2. Treatment Process: The AO process breaks down large molecular organic matter into small molecules in the anaerobic stage, improving the biodegradability of sewage, and in the oxic stage, microorganisms oxidize organic matter and perform nitrification and denitrification to achieve nitrogen removal.
In response to the characteristics of medical and domestic wastewater, the project adopts the AO (Anaerobic-Oxic) process as the core treatment technology. The AO process combines the advantages of anaerobic and aerobic biological treatment technologies, featuring high treatment efficiency, good effluent quality, and stable operation. In the anaerobic phase, anaerobic bacteria decompose organic matter in sewage into small molecular organic matter and release phosphorus and other nutrients; in the aerobic phase, aerobic bacteria further oxidize small molecular organic matter into inorganic matter, while absorbing phosphorus and other nutrients, thus achieving purification of sewage and recovery of resources.
Specifically, the advantages of the AO process are reflected in the following aspects:
- High efficiency in removing organic matter: Through the synergistic action of anaerobic and aerobic stages, the AO process can efficiently remove organic matter from sewage, including refractory organic pollutants.
- Good nitrogen and phosphorus removal effects: While removing organic matter, the AO process can also effectively remove nitrogen and phosphorus, meeting strict discharge standards.
- Stable operation and easy maintenance: The AO process has a high resistance to shock loads, stable and reliable operation; at the same time, the equipment maintenance of this process is relatively simple, reducing operating costs.
3. Treatment Equipment: Integrated sewage treatment equipment is suitable for small to medium-sized sewage treatment projects, which can be installed on the ground or buried underground, with the advantages of small footprint, simple management, and high degree of automation.
4. Equipment Features:
- Strong resistance to shock loads, with an average retention time of more than 6 hours in the contact oxidation method.
- Nitrogen and phosphorus removal capabilities, which can be adjusted by changing the structure of the equipment to adapt to the treatment of different wastewaters.
- Stable effluent quality, low sludge production, and easy handling.
- The equipment can be installed on the ground or buried underground, with the top covered for greening when buried underground, resulting in a small plant footprint and few above-ground structures.
- Easy to achieve automatic control, with simple management operations.
After treatment by the AO process and integrated sewage treatment equipment, the effluent quality of hospital sewage has reached the local discharge standards in Pakistan, and even exceeds some international standards. The successful implementation of the project not only effectively reduces the pollution of hospital sewage to the surrounding environment and improves the local water quality, but also achieves significant environmental and economic benefits.
