Treatment of hospital wastewater: Technology system and Process

Hospital Wastewater Treatment

Hospital wastewater treatment is the process of removing pollutants, bacteria, viruses, and other harmful substances from wastewater generated from medical activities, surgeries, and patient care. This process includes steps such as pretreatment, biological treatment, chemical treatment, and disinfection to ensure that the wastewater meets safety standards before being discharged into the environment.

Benefits of Hospital Wastewater Treatment

The benefits of hospital wastewater treatment include:

• Environmental protection: Minimizing water, soil, and air pollution.
• Community health: Preventing the spread of infectious diseases from medical wastewater.
• Compliance with regulations: Meeting government environmental and health regulations.
• Cost savings: Reducing costs of wastewater treatment and clean water.
• Water reuse: Treated water can be reused for various purposes.

In addition, untreated wastewater from healthcare facilities can affect human health and cause community diseases. Untreated wastewater discharged directly into ponds, lakes, etc., seeps into the ground, causing serious environmental pollution. Therefore, we need hospital wastewater treatment systems.

Methods of Hospital Wastewater Treatment

Given the hazardous nature of hospital wastewater to humans and the surrounding environment, it is essential to apply optimal methods for treating medical wastewater:

AO Hospital Wastewater Treatment Technology

AO technology is suitable for about 80% of healthcare facilities today because it effectively treats BOD, COD, Ammonia, Nitrate. The treated wastewater meets the standards of QCVN 28:2010 - BTNMT - Column A.

For wastewater from large hospitals with high medical waste and biohazard materials, AAO technology is applied.

AAO Combined with MBBR Method

Abbreviated from Anaerobic - Anoxic, this continuous biological treatment process, along with 3 microbial communities, anaerobic, anoxic, and aerobic, is used to treat wastewater. AAO wastewater treatment technology is often used for large hospitals with severely polluted wastewater.

Trickling Biofilter

Simple operation and maintenance, low energy consumption, making it cost-effective. The installation and operation processes are simple, and the filter media layer needs to be checked and replaced periodically to ensure filtration efficiency.

Stable Biological Pond Method

Commonly used with secondary wastewater sources to decompose organic matter naturally. This method significantly optimizes costs for water treatment. However, with a large volume of wastewater, this can be challenging.

Essential Equipment in Hospital Wastewater Treatment Systems

Hospital wastewater treatment is a critical issue to ensure a safe and clean living environment. The hospital wastewater treatment system includes various types of equipment to remove pollutants and harmful bacteria before discharging the water into the environment. In this article, we will learn about three important types of equipment in this system.

Sedimentation Tank

The sedimentation tank is one of the most important devices in the wastewater treatment system. Its main task is to separate suspended solids from wastewater. This process occurs in two stages: gravity settling and quiescent settling. Solid particles gradually sink to the bottom of the tank, allowing the wastewater to continue to the next treatment steps.

Biological Filter Tank

The biological filter tank is an essential device in hospital wastewater treatment. This device uses microorganisms to decompose organic matter in wastewater.

The biological filter tank typically consists of filter media layers such as sand, gravel, and activated carbon, where microorganisms can live and function. The biological filtration process helps minimize the amount of pollutants, improving water quality before discharge into the environment.

Disinfection Machine

The disinfection machine plays a crucial role in removing bacteria and viruses from wastewater. There are various disinfection technologies, with the most common being UV light and chemical disinfection like chlorine.

UV disinfection machines use ultraviolet light to kill bacteria, while chlorine works by destroying the cell structure of microorganisms. Disinfection ensures that the treated wastewater no longer contains disease-causing agents, making it safe to discharge into the environment.

Monitoring and Control System

In addition to the main treatment devices, a modern hospital wastewater treatment system also requires an automatic monitoring and control system. This system includes sensors and measuring devices to monitor water quality throughout the treatment process.

Through the collected data, the control system can automatically adjust operating parameters such as flow rate, chemical concentration, and treatment time, ensuring that the wastewater always meets standards before being discharged into the environment.

Wastewater Reuse System

In an increasingly water-scarce world, reusing treated wastewater is a sustainable and effective solution. Wastewater reuse systems can be integrated into the treatment process, allowing treated wastewater to be reused for non-potable purposes such as irrigation, car washing, or industrial cooling systems.

Training and Awareness

Finally, for an efficient hospital wastewater treatment system, training staff on operation and raising community awareness about the importance of wastewater treatment is essential. In-depth training courses help staff understand the operation and maintenance procedures, while awareness programs help the community understand and support environmental protection measures.

Hospital Wastewater Treatment Process

Currently, the integrated medical wastewater treatment technology consists of the following 4 basic steps:

1. Pretreatment Stage

Using mechanical methods to remove large-sized oil, grease, debris, etc., from wastewater.

This stage is extremely important to ensure the efficiency of the system and that the treated water meets the quality standards.

2. Primary Treatment Stage

This stage removes suspended solids from wastewater. Equipment such as screens, primary settling tanks, clarifiers should be used.

• Screens: used to remove debris before entering pumping stations or centralized treatment facilities to prevent blockages.
• Settling tanks: used to separate sand and inorganic substances in wastewater.

3. Secondary Treatment Stage

Remaining substances in wastewater such as P-PO43-, N-NO3-, COD, BOD5, N-NH4+, are removed through the action of microbial communities in anaerobic, anoxic, and aerobic processes.

Common techniques used in this stage include biological filter tanks, submerged biological filter tanks, trickling biofilters, rotating biological contactors, traditional activated sludge tanks, sequencing batch reactors, and oxidation ditches.

4. Post-Treatment Stage

This is the final wastewater treatment step before discharge into the external environment. The main disinfection methods used in this stage are disinfection using UV ultraviolet light, chlorine or chlorine compounds, and ozone disinfection.

Finally, sludge treatment is carried out, and clean water meeting standards is discharged back into the environment for reuse.

With many years of experience and a team of technical experts, Toan A is committed to being a leading provider of hospital and medical wastewater treatment methods today. Contact us if you have any questions, and we will help you find the answers.