Zero liquid discharge (ZLD) and the Rising Global Industrial Adoption of Zero Liquid Discharge
Zero liquid discharge (ZLD) is a strategic wastewater management system that ensures that there will be no discharge of industrial wastewater into the environment. It is achieved by treating wastewater through recycling and then recovery and reuse for industrial purpose. Hence ZLD is a cycle of closed loop with no discharge.
Factors that motivate the ZLD system are:
- Water scarcity
- Water economics
- Environmental regulations
Different methods can be employed to achieve ZLD:
- Thermal process (evaporation)
- Reverse osmosis: RO (membrane technology)
- Electro dialysis
- Forward osmosis
- Membrane distillation
A systematic ZLD is made up of the following components:
- Pretreatment (physicochemical and Biological)
- RO (membrane processes)
- Evaporator and crystallizer (thermal processes)
In addition to ZLD, the recovery and reuse of salt reduces the amount of sludge. This achieves ZWD. The adoption of ZLD requires extensive research and a pilot study because the wastewater generated is not the same for different processes. Above all, it must be financially viable. The type of industry that can afford it may have an effluent treatment plant to achieve ZLD; and those that cannot afford it may become a member of a common effluent treatment plant (CETP). CETP is a project that has been implemented successfully in Tirupur, the leading hosiery hub of India.
There are benefits of ZLD:
- Wastewater discharge is avoided by recycling.
- Recovery of water and salt aids in reducing the cost of operation of ZLD.
- It promotes the sustainability of the industry and the environment at large.
- There is less use of water by the textile industry, which means water is available for other purposes such as irrigation (agriculture) and domestic utilities.
- ZLD helps recover the environment.
- The sludge can be effectively used by the cement industry.
Key Market Insights
The global zero liquid discharge market size stood at USD 0.71 billion in 2018 and is projected to reach USD 1.76 billion by 2026, exhibiting a CAGR of 12.1% during the forecast period (2019 – 2026).
The zero liquid discharge market growth is driven by the increasing adoption of these systems in recent years owing to stringent government regulations regarding wastewater discharge. Wastewater discharge leads to destabilization of the ecosystem and hampers water bodies. Zero liquid discharge systems aim at removing all liquid and solid waste from a system and produce clean water that is suitable for reuse. The solid waste captured can be reused in various industrial processes. The clean water obtained from zero liquid discharge water treatment systems is used as a coolant for systems and also for the different industrial processes such as cooling tower blowdown, boiler blowdown, oil refinery effluent, etc.
- Growing Urbanization Directly Drives the Zero Liquid Discharge System Installations
The growing urbanization is being witnessed all over the globe, which has resulted in surplus demand for energy and water. This has directly impelled energy producers to produce more and also be efficient with the same. With growing production from power plants, the discharge to water bodies also needs to be under control, which drives zero liquid discharge system installations. Following this trend, ZLD market size will increase at a healthy rate.
- Globally Increasing Water Stress Drives the Need for Wastewater Recycling
Humans can use only 3% of water present on the earth’s surface. Rising population is pushing government authorities to provide other alternatives for satisfying the increasing water demand, which is one of the leading zero liquid discharge market trends. Recycling the wastewater generated from power plants & industries and reusing the recycled water for various industrial processes serves this purpose. ZLD (Zero liquid discharge) water treatment systems & specialized in providing these services; this acts as an opportunity for market growth.
- Stringent Regulations Regarding Discharge of Specific Solutes to Water Bodies to Boost the Market
The major factor driving zero liquid discharge systems market growth is the imposed regulations on industries and power plants regarding emissions in water bodies. ZLD systems are mainly deployed for the industrial sector, as major harmful emissions to water bodies and aquatic ecosystem originate from these. The emissions include mercury, arsenic, lead, selenium, salt, toxic elements, nitrate, etc. that result in a misbalance of the ecosystem.
Zero liquid discharge water treatment systems result in zero emissions being made to water bodies, and the collected purified water is reused in the industry. This has led to increased adoption of these systems and certain mandates introduced, which drive their adoption and therefore drive the market growth. For example in October 2017, the environment industry in India tweaked standards for four parameters which determine the water quality. The parameters included were pH value, Bio chemical oxygen demand, total suspended solids and fecal coliform.
- High Efficiency in Operation of ZLD Systems to Fuel the Market
As the demand for water rises, recycling of water with efficient techniques has become an important factor in sufficing the water needs. ZLD systems are efficient in working and result in 70%-90% of wastewater reuse. As per the economics of water, recycled water becomes more affordable as compared to water supply from conventional sources. Also, zero liquid discharge can act as a more accessible and economical solution in cases where waste needs to be transported in huge volumes over long distances. These advantages of the ZLD will augment the ZLD market demand during the given forecast period.
Segmentation of Market
By Technology Analysis
- Efficient Filtration Techniques in Membrane Based Systems Will Drive their Growth
Based on type, the market is classified into thermal-based and membrane-based systems. Membrane-based systems account for major share in the market owing to better efficiency in operation and preference given by the industry for their installation over thermal-based installations. The various techniques used in membrane-based installations are reverse osmosis, nanofiltration, electrodialysis, and natural evaporation. Reverse osmosis is the most used technique used in ZLD as it recovers most of the water and reduces the cost of ZLD. The thermal-based systems utilize the basic crystallization and evaporation techniques for water treatment.
By Application Analysis
- Escalating Energy Demand Will Drive ZLD Installations in Energy & Power Sector
By application, the market segments include energy & power, food & beverages, chemical & petrochemical textiles, pharmaceutical, others. Growing population, coupled with rapid urbanization, has resulted in increased energy demand across the globe. This has led to more industries and power plants to be constructed. Thermal power plants are the major sector for the application of ZLD. Thermal power plants still cover a major portion of energy supply, and this factor certainly pushes the ZLD installations in the sector.
Asia-Pacific holds the maximum growth opportunities for the market during the given forecast period. China and India are the countries that are making noticeable investments in the wastewater treatment plants. Europe also holds significant growth opportunities, with Germany, UK, and Italy being the leading nation investing in the wastewater treatment. The Middle East & Africa and Latin America will also witness healthy growth in the market size with increasing urbanization and power demand in the regions.
As water scarcity becomes an important issue around the globe with increasing population and urbanization, zero liquid discharge systems are bound to become an integral part of the industrial sector. This will ensure water recycling and wastewater treatment that also will help in productive usage of the captured waste. Also, the economic advantages of these systems, coupled with steps to improve working efficiency, will drive the market growth in the coming years.