Freshwater scarcity is one of the most critical global challenges that pose a major threat to economic growth, water security, and ecosystem health. The challenge of providing adequate and safe drinking water is further complicated by climate change and economic development, and industrialization pressures. The public and industrial sectors consume substantial amounts of freshwater while producing vast quantities of wastewater. If inadequately treated, wastewater discharge into the aquatic environment causes severe pollution that adversely impacts aquatic ecosystems and public health. Recovery and recycling of wastewater have become a growing trend in the past decade due to rising water demand. Wastewater reuse not only minimizes the volume and environmental risk of discharged wastewater but also alleviates the pressure on ecosystems resulting from freshwater withdrawal.
Zero Liquid Discharge (ZLD) is a treatment process designed to remove all the liquid waste from a system. Reducing wastewater economically and producing clean water suitable for reuse is the focus of ZLD. ZLD systems employ advanced wastewater treatment technologies to purify and recycle wastewater produced in industries. ZLD prevents the risk of pollution associated with wastewater discharge and maximizes water usage efficiency, thereby striking a balance between exploiting freshwater resources and preserving aquatic environments.
Another important reason to consider zero liquid discharge is the potential for recovering resources present in wastewater. Some organizations target ZLD for their waste because they can sell the solids produced or reuse them as a part of their industrial process. Stringent regulations, water scarcity, water economics, rising expenses for wastewater disposal, and increasing freshwater value are driving ZLD to become a beneficial or even a necessary option for wastewater management. The major benefits of ZLD technology include:
- Reduce trucks associated with off-site wastewater disposal and their associated greenhouse gas impact and community road incident risk.
- Improved environmental performance and regulatory risk profile for future permitting
- Lowered waste volumes decrease the cost associated with waste management.
- Recycle water on-site, lowering water acquisition costs and risk. Recycling on-site can also result in less treatment needs versus treating to meet stringent environmental discharge standards.
Some processes may recover valuable resources, for example, ammonium sulfate fertilizer or sodium chloride salt for ice melting.
In recent years, ZLD desalination has attracted the scientific community and industry's increased interest as a promising strategy for wastewater management. This is mainly due to its ability to enhance water usage efficiency while reducing brine discharges and water and disposal-related environmental impacts.
Moreover, various regulations have been formulated and implemented by concerned environmental agencies and government authorities to conserve water and prevent water pollution. Agencies such as Environmental Protection Agency U.S., European Water Association, and India Water Works Association, and government bodies are actively involved in setting regulations governing water discharge and reuse. Efforts toward treatment and water conservation are estimated to boost the demand for ZLD systems across the globe over the assessment period.
ZLD is also increasingly being mandated across various industrial sectors in China and India to better control polluted wastewater discharges to water resources and groundwater systems. In China, the government’s 12th Five-Year Plan, which includes objectives to enhance environmental protection, mandates ZLD in new and existing coal-fired power plants and coal-to-chemical refining facilities for treating complex industrial process waste streams. ZLD requirements in India extend to a range of industrial sectors, including power, pharmaceutical, chemical, textile, and food and beverage.
Henceforth, the increasing application of ZLD technology has been witnessing rapid growth in the tertiary water and wastewater treatment technologies market across the globe, which is expected to grow at a CAGR of 7.2% during the forecast period to be valued at USD 35.5 billion by 2027, according to the latest publication of Meticulous Research®.