SOLUTIONS TO REUSE WASTE WATER
Today, many regions of the world are facing a shortage of potable water, the reuse of treated wastewater can provide suitable alternative water sources to meet most water needs, except except for drinking water that requires higher quality.
The purpose of water reuse is increasing in urban areas of many countries, including landscape spraying; industrial use; flush toilets and urinals; used for fire fighting and extinguishing, street cleaning; used for recreational and environmental purposes (water has a decorative nature, supplementing water bodies); wash vehicles and vehicles. These centralized water reuse systems have grown to the point where they are considered effective components of urban water management and are widely used in many cities and countries around the world. The current situation of wastewater reuse in Vietnam is still quite low. In the context that Vietnam is strengthening international economic integration and actively participating in multilateral trade agreements. This policy has strongly promoted the acquisition and application of world’s advanced technologies and techniques, including the harmonization of national standards with international and regional standards in order to applicable to Vietnam, such as the TCVN on water environment protection and water quality. However, the system of these documents is still incomplete, lacks synchronization and lacks details. A clear example is Decree 80/2014/ND-CP stipulating that the Ministry of Natural Resources and Environment shall assume the prime responsibility for, and coordinate with concerned ministries and branches in, promulgating TCs and QCs on the use of treated wastewater in accordance with each item. the purpose of using recycled wastewater (Article 24) has not been fully realized so far. From there, we see the urgency in developing standards for water reuse in Vietnam’s conditions, serving different purposes of water use.
Types of reuse of domestic wastewater
The World Health Organization (WHO) recommends using recycled domestic wastewater in the following 4 areas:
(I) Reuse of wastewater in urban areas:
A large number of urban water uses do not require high water quality such as potable water. Treated urban domestic wastewater, depending on demand, can be reused for the following purposes: Watering trees, washing roads; flush toilets; Water supply for fire fighting, Re-landscape of urban rivers and lakes.
(II) Reuse of wastewater in agriculture:
Agro-forestry production is the most important production sector for the development of Vietnam. Agriculture is also the largest user of water. The use of water after treatment to irrigate crops first needs to know the quality of the wastewater, especially the indicators of nitrogen, potassium and various trace elements such as zinc and sulfur which are not important factors. indispensable for plants. However, in some cases these substances should not exceed the requirements of the crop, avoiding contamination of shallow groundwater sources.
(III) Reuse of wastewater in industrial production:
Industrial wastewater flows account for about 20% of global freshwater. It is forecasted that the demand for water by 2025 will increase by 1.5 times. Therefore, the reuse of industrial wastewater not only brings general benefits to the environment, but also significantly reduces production costs, recovers water resources, especially reduces related costs. to wastewater treatment and discharge to receiving sources.
(IV) Supplement for groundwater:
Replenishing the aquifer can help prevent subsidence, reduce groundwater levels, prevent saltwater intrusion, and maintain groundwater resources for future needs.
Reusable wastewater treatment methods
1. 2 processing
Secondary treatment processes such as: activated sludge biological processes (AO, A2O, MBBR, oxidation channels, SBR), drip biological filtration, biological process combined with MBR membrane, biological pond, etc. biofilter…
The treated water has BOD, TSS ≤ 30 mg/l.
2. Filtering (After secondary processing)
Filtration processes such as bulk filtration with granular filter media, surface filtration, fiber filtration, disc filtration and membrane filtration types (NF, UF, RO membrane).
3. Disinfection
Disinfection destroys pathogenic microorganisms by chemical, physical or biological methods: Cl2, O3, other chemicals, UV rays, or other processes so that the recycled wastewater meets the requirements for use.
4. Advanced processing
Advanced wastewater treatment processes such as chemical precipitation, activated carbon adsorption, ion exchange, reverse osmosis (RO) and other membrane processes.
MPTEK specializes in providing solutions to reuse wastewater for purposes such as water supply for industrial production, irrigation…
Contact us now for advice and find the best solution for you!
MPTEKI SOLUTIONS CO., LTD
Hotline: 0903188563
Address: 20 Huynh Thien Loc, Hoa Thanh Ward, Tan Phu District, HCMC.