Latest water purification technologies

02 Jun.,2022

Water Technology lists the latest water purification technologies likely to serve as alternatives to existing water purification processes.

 

Containerized Water Treatment Plant

Global water treatment product manufacturers are exploring state-of-the-art water filtration technologies such as carbon nanotubes and advanced membrane systems to better serve their customers.

Water Technology lists five of the latest water purification technologies that are likely to serve as alternatives to existing water purification processes.

Nanotechnology

Nanotechnology involves several approaches and processes of applying materials on the atomic or molecular scale. Nanotech-based water purification processes are considered to be modular, highly efficient and cost-effective when compared to conventional water purification methods.

The major applications of nanotechnology in water treatment processes include silver, copper and zero-valent iron (ZVI) nanoparticles, nanostructured photocatalysts, nano-membranes, and nanoadsorbents.

The large surface-to-volume ratio of nanoparticles enhances the adsorption of chemical and biological particles, while enabling the separation of contaminants at very low concentrations. Nanoadsorbents feature specific physical and chemical properties for the removal of metallic pollutants from water.

Carbon nanotubes (CNTs) are considered to be one of the prominent nanomaterials used in water purification. CNT-based filtration systems can remove organic, inorganic and biological compounds from water.

Global companies such as Alfa Laval, Applied Membranes, DowDuPont, GEA Group, Inopor, and Koch Membrane Systems are involved in the development of membranes that are made of nanomaterials to eliminate pollutants during the treatment.

Acoustic nanotube technology

The acoustic nanotube technology was invented by scientists at Nasa’s Johnson Space Center. It employs acoustics in place of pressure to direct water through small-diameter carbon nanotubes.

The technology is based on an acoustically driven molecular screen integrated with carbon nanotubes that allow the passage of water molecules while blocking any larger molecules and contaminants. It consumes less power than traditional filtration systems and drives water away from contaminants instead of removing pollutants from water. The process also eliminates the need for flushing the filter system.

The primary applications of acoustic nanotube technology are municipal water plants, medical facilities, laboratories, distilleries, desalination plants, industrial facilities, wastewater treatment plants, and consumer segment. The innovation is scalable with the integration of multiple filters, according to the filtration needs of users.

Nasa’s patented acoustic nanotube technology is available for the firms to license and evolve into a commercial water purification product offering.

Photocatalytic water purification technology

Water treatment using photocatalysis has gained prominence in recent years due to its efficiency in treating contaminated water. The technology utilises photocatalyst and ultraviolet (UV) rays to remove toxic substances from water.

Panasonic developed a technology that binds the photocatalyst (titanium dioxide) to a commercial adsorbent and a catalyst called zeolite, ensuring effective separation and recovery of photocatalysts from the water for reuse. Titanium dioxide can mineralise a range of organic compounds into safe end products. The catalyst uses UV radiation either from sunlight or artificial light to separate substances.

Photocatalysis can break down a range of organic materials, estrogens, pesticides, dyes, crude oil, and microbes such as viruses and chlorine-resistant pathogens, as well as inorganic compounds such as nitrous oxides.

Photocatalytic water treatment systems are suitable for use in water and wastewater treatment facilities and can treat industrial wastewater polluted with high loads of organic substances or metals.

Aquaporin Inside™ technology

Aquaporin Inside™ technology from Danish cleantech company Aquaporin is based on the bio-mimetic water treatment membrane design. Aquaporins enable quick and highly selective water transfer across the cell membrane. They allow the cell to regularise its volume and internal osmotic pressure in line with the hydrostatic and osmotic pressure differences.

The aquaporin channel’s distinct architecture allows the passage of water molecules and blocks all other compounds. The natural bio-mimetic membranes also serve as a basis for the development of artificial bio-mimetic membrane systems. The technology is being used in industrial and household water filtration and purification systems.

The Aquaporin Inside membranes are the only membranes in the market to employ aquaporins to purify drinking water. The membranes are available for both forward osmosis (FO) and reverse osmosis (RO) applications.

The Aquaporin Space Alliance (ASA), a joint venture between Aquaporin and Danish Aerospace Company (DAS) is commercialising the patented Aquaporin Inside™ technology in space applications and space programmes, in collaboration with European and US-based firms.

Automatic Variable Filtration (AVF) technology

Automated Variable Filtration (AVF) technology involves a simple process where upward flow of influent is cleaned by downward flow of filter media. It eliminates the need for any additional process or freshwater for filter media cleaning.

The AVF method employs continuously cleaned descending bed filters embedded in a variable array. The two-stage configuration of the system integrates two sets of media filters that can function either in serial or parallel mode.

The process delivers water with quality equivalent to that of micro-filtration technology and at a fraction of the cost of low-pressure membranes. It features no moving parts and consumes less power, offerings savings on reduced operating and maintenance costs.

AVF systems are suitable for municipal drinking water and wastewater treatment, wastewater recycling and reuse, pre-filtration for membrane processes and desalination applications.

R2O Water Technologies, Process Research ORTECH (PRO), and Eureka Forbes are some of the major companies involved in the development of AVF technology-based products and services.