Water and Wastewater Treatment

Ionic has several technologies that can be applied in water and waste water markets globally to address some of the world’s greatest challenges for clean drinking water and environmental de-contamination.  The Company’s adsorption and nano-filtration technologies will have extensive application in these markets, beginning with removal of organic materials from ‘clean’ water and waste water.

These technologies are currently in the product development phase and, in partnership with Clean TeQ, Ionic’s will commercialise them in the next 18 to 24 months.  Ionic’s technologies, once developed to a commercial stage, will provide complementary water treatment capabilities to Clean TeQ’s existing suite of technologies.  Both of Ionic’s technologies focus on removing organic materials from water whereas Clean TeQ’s existing technologies are used for removal of ionised particles and desalting processes.

Of Ionic’s technologies, SuperSand is an adsorbent material that can be tailored to attract and “adsorb” organic particles as water is passed through it, whereas nano-filtration GO membranes are designed to filter out particles allowing only treated water past.  Both technologies are complementary and can be used to target different compounds and particles at distinct stages in the water treatment process.

Extensive Australian Government funding has been secured through the Cooperative Research Centre – Programs initiative, which greatly increases the likelihood of adoption in these endeavours and demonstrates wide-spread support for the technologies.  Ionic, in collaboration with Monash and CleanTeQ will spend over AUD 1.1 million on developing this technology to market readiness over the next 18 months.

SuperSand

Sand has been used in water filtration for hundreds of years.  Ionic’s SuperSand technology takes this simple water filtration method to an advanced level by applying a coating of GO to sand particles.  SuperSand will provide the benefits of the mechanical properties of sand in a continuous filtration application patented and commercialized by CleanTeQ. The adsorption of organics materials (COD) onto graphene oxide (GO) coated sand is the additional step in removing COD from micro-screened wastewater to meet the 80 – 90% COD reduction benchmark, a problem identified by the industry. The dried GO coating retains its chemical functionality on a massive surface area, which enables it to “adsorb” contaminants in the water.  Most importantly, the chemical functionality can be tailored to target specific contaminants.

Photographic images and Energy-dispersive X-ray spectroscopy analysis of sand and SuperSand

Photographic images and Energy-dispersive X-ray spectroscopy (EDAX) analysis of sand and SuperSand. EDAX analysis from the surface of the grains clearly showed a significant increase in carbon content which indicates much higher adsorptive capabilities.

Since Associate Professor Majumder’s original publication on GO coated sand in 2011, the research team has made a number of advances in the technology bringing it steadily closer to commercialisation.

Being the simplest and most researched of its technologies, the Company expects SuperSand to be the first commercial product to incorporate its graphene technologies.

supersand technology

Column test results for Rhodamine B (a common probe molecule) removal with SuperSand and activated carbon show superior performance of SuperSand compared to activated carbon (Flow rate: 1 ml/min. Column height: 400 mm; Column diameter: 6.6 mm.)

The next stages in the program, which Ionic aims to complete in the next 12 months, are set out below.

Upscaling Production

  • Modification and optimisation of the materials and methods required for the production of the GO adsorbents to demonstrate scalable production and commercial potential based on the assessed cost of manufacturing

Recovery and Reuse

  • Implementation of chemical biological and electrochemical recovery methods for the recycling of adsorbent material
  • The ability to re-use the rGO is of significance and may have a significant impact on cost and therefore enhance the commercial viability of the process.

Operational Testing

  • Demonstration of adsorption and membrane technologies using pilot and demonstration scale equipment. The pilot scale equipment will be operated at Clean TeQ’s premises in Notting Hill in Victoria while demonstration scale testing will be operated at a Victorian wastewater treatment plant

GO Membranes for Nano-filtration

A logical extension of Ionic’s expertise and IP in graphene-enabled water filtration is in the use of Reduced GO (rGO) as a membrane for nano-filtration of bacteria, viruses, organics and some salt species. The currently available membranes, usually produced using a vacuum filtration processes, generally have high energy requirements when used for tight filtration and the fouling characteristics are severe in many circumstances. The development and use of a rugged, non-fouling, low pressure membrane that removes dissolved organics will be an economic leader in the membrane industry.  Ionic’s rGO membranes can meet these requirements.  GO, in contrast to impermeable pure graphene, is ideally suited to filtration applications and Ionic’s expertise in tailoring GO to create customised pore size and performance characteristics is critical in leveraging this market opportunity.

Conventional polymeric nanofiltration membranes usually have limited chemical resistance, while ceramic membranes are not cost-efficient. Graphene is a one atom thick two-dimensional honeycomb carbon lattice, which is an exciting multifunctional material and possesses a combination of strong mechanical properties, chemical inertness and extremely large surface area. Membranes prepared from graphene possess the best of both worlds: they are chemically inert like ceramic membranes and can be made into films using graphene/GO fluid phase dispersions like polymer membranes. Novel and exciting properties of graphene-based membranes such as high permeability and high selectivity for both liquids and gases have been reported.

Ionic’s rGO membranes, created using our proprietary shear alignment process, can be tailored for the efficient and effective removal of a wide range of contaminants and materials from water or other liquids.  Our shear-aligned membranes (SAMs) have a range of extraordinary properties that will deliver superior performance to current polymer or ceramic-based technologies, for example:

  • High chemical resistance making them safer and lower maintenance;
  • 10 x higher flux than polymer membranes resulting in much greater efficiency;
  • High mechanical strength for reduced maintenance and lifetime cost;
  • Tuneable selectivity during manufacture for precise customisation.
Ionic's proprietary process for producing SAMs

Ionic’s proprietary process for producing SAMs involves a specially formulated rGO ink (nematic phase GO) that can withstand the shear forces required to align the GO sheets to form the SAMs)

onic's SAMs retention rate for a wide range of probe molecules

Ionic’s SAMs show high retention of a wide range of probe molecules with different charges and sizes demonstrating excellent potential for nanofiltration applications. ((MV is methyl viologen, MR is methyl red, MnB is methylene blue, MO is methyl orange, OG is orange G, Ru is Tris (bipyridine) runthenium (II) chloride, RB is Rhodamine B, RosB is Rose Bengal, MB is methylene blue, BB is brilliant blue. The green, red and blue symbols represent electroneutral, negatively and positively charged probe molecules, respectively.)

Compared to membranes manufactured using vacuum filtration methods, Ionic’s membranes perform significantly better.  They demonstrate much higher permeability and flux as well as higher retention of the common probe molecule, methyl red.

comparison SAM vacuum filtration membrane performance

Comparison of SAM and vacuum filtration membrane performance. (a) Water permeability versus thickness, and (b) Retention of methyl red, an electroneutral probe molecule. Inset of b is the structure of the methyl red. Error bars in these figures are from five measurements showing the maximum and minimum values.

water flux vs applied pressure different membranes

Water flux versus applied pressure for three different membranes: SAM (red) with a thickness of 150±15 nm, vacuum filtration (blue) with a thickness of 170±20 nm, and NF270, a commercial nanofiltration membrane (green). SAM showed a retention of 90±2% for methyl red, while the vacuum filtration membrane and NF270 showed 50±5% and 90±1.5% retention, respectively.

gravure printing machine inset images

The gravure printing machine and (inset) images of 13 x 14 cm2 GO membranes

Next stages in the research and development of these membranes will involve:

Materials optimisation

  • Modification and optimisation of the materials and methods required to produce the GO membranes

Nanofiltration method refinement

  • Implementation of various nanofiltration methods including dead end and cross flow processes for the membrane material.

GO manufacturing specification

  • Demonstration of ability to manufacture GO materials to meet the specification for nanofiltration.

Up-scaled demonstration

  • Demonstration of the processes at scale including 30mL, 2L capacity.

Pilot and industrial testing

  • Demonstration of membrane technologies using pilot and demonstration scale equipment.

The research team has received international acclaim for its work on GO membranes.  In April 2015, Associate Professor Majumder presented his work on ‘Graphene-based fluidic systems: From compact micro/nano-fluidic devices to large area filtration membranes’ to the Royal Society London.  The event, titled ‘Nanostructured carbon membranes for breakthrough filtration applications: advancing the science, engineering and design‘, featured talks by the leading researchers on filtration from the UK, France, USA, Switzerland, Germany, South Korea and Australia.

Markets for Water and Wastewater Treatment Technologies

Municipal wastewater is a vast and underutilised source of fresh water but current treatments, using current biological and membrane processes, are energy intensive.  Global population growth and urbanisation growth is placing severe demands on fresh water supplies and freshwater scarcity is driving the uptake of new technology in many developing areas around the world.  Water is a critical input for power generation, and potable water is a critical input for food production and many industrial applications.  Technology that can treat contaminated freshwater sources such as groundwater, surface water, municipal and industrial wastewater to a quality level for use at an affordable operating cost will be a game changer for the industry.

A number of dynamics are driving the global market for water and wastewater treatment:

  • Currently only 20% of globally produced waste water receives proper treatment.
  • An estimated 90 per cent of all wastewater in developing countries is discharged untreated directly into rivers, lakes or the oceans.
  • Water is being demanded at a CAGR of 7% in the next five years and water industry is growing at a CAGR of 3.9 % for the next five years.
  • The global wastewater market size is USD 262 Billion as of 2014 and is expected to grow at a rate of 4.5% to reach USD 313 Billion by 2018, municipal wastewater has the highest share of 92%, and industrial waste water has an 8% share.[1]

The countries expected to see the fastest growth include the BRIC (Brazil, Russia, India, and China) countries and other countries with large, developing industrial bases and stressed local water resources.

In developing countries, opportunities are likely to be based on the continued growth of water-intensive industries and rising investment in water and waste infrastructure, particularly in areas that need to tap brackish or otherwise poor-quality water resources.

Wastewater contains the debris of our daily lives including faeces, fat, food scraps, detergents and pharmaceuticals.

Global wastewater market

Global wastewater market (https://wikibizpedia.com/Global_Wastewater_Treatment_Market)

In chemical terms, 1m3 of domestic wastewater contains 300 to 600 grams of carbon-rich organic matter (known as carbonaceous chemical oxygen demand, or COD), 40 to 60 grams of nitrogen (in the form of ammonium and organic compounds), 5 to 20 grams of phosphorus (in phosphates and organic compounds), 10 to 20 grams of sulphur (mainly as sulphate) and traces of heavy metal ions.

Historically, wastewater is screened and de-gritted before being held in retention tanks where organics and nutrients are biologically aerobically oxidised. The bio-solids are then removed in a clarifier to produce the treated effluent.

The process has a large energy and carbon footprint.  A medium sized plant (e.g.100,000 m3 of water per day) consumes as much electricity as a town of 5,000 people (around 0.6 kWh per m3 of wastewater) and emitting as much CO2 as 6,000 cars per day. The technology also produces large volumes of bio-solids (sludge) which must be managed.

As increasingly stringent energy and environmental performance indicators are set by governments, there is a critical need for utility companies to implement low energy, low sludge wastewater treatment options.  If suspended and dissolved COD in wastewater can be reduced by 80 – 90% in a low energy separation or filtration process, then the need for the energy intensive secondary processes would be significantly reduced.

A solution to these problems requires a low energy, continuous flow processes for the wastewater treatment market and the use of novel adsorbents and nanofiltration membranes to adsorb or filter out dissolved organics (COD) in a continuous flow process.

Current products for adsorption (such as activated carbon) and polymer membranes do not meet the criteria for continuous processing, low energy use and high water recovery.  GO-based water treatment products have the potential to meet these requirements.

While polymer-based technologies currently dominate the market, graphene membranes represent the next wave of evolution in this market and have enormous disruptive potential.

Ionic’s GO membranes will target the global market for filtration membranes.

market for wastewater treatment services

The market for wastewater treatment services addresses demand in a broad range of industries which means a large number of opportunities (http://www.waterworld.com/articles/iww/print/volume-11/issue-1/feature-editorial/survey-examines-wastewater-treatment-costs.html)

To the extent those targets involve water purification, including mine remediation, waste water, drinking water, desalination, brackish water or any other contaminated or polluted waters, those targets and markets will be addressed under the Clean TeQ Commercialisation Agreement.

The global membranes market is projected to grow at a CAGR of 9.47% from 2015 to reach a value of USD 32.14 Billion by 2020.  While growth in ceramic membranes is projected to be highest, other types of membranes, including include Ionic’s GO membranes, are projected to grow at a CAGR of 12.05% between 2015 and 2020.

The market in membranes specifically for nanofiltration is projected to witness an estimated growth rate of in excess of 12% between 2015 and 2020 with water & wastewater treatment applications accounting for the largest market share of approximately 39%.  With increasing population, growing demand in chemical industries, and growing demand in the pharmaceutical & medical sector, Asia-Pacific is projected to generate a huge demand for membranes and witness an estimated growth rate of in excess of 12%, followed by Middle East and Africa with an estimated growth rate of in excess of 10.4% between 2015 and 2020.