30 Diesel Generators Installed At Victorian Desalination Plant

An electrical fault at Victoria’s desalination plant has forced the operator to install 30 diesel generators the size of shipping containers as an emergency back-up power supply.

Electrical equipment that links an underground cable to the desalination plant at Wonthaggi was damaged during a maintenance shutdown in December.

The Victorian Government has placed an order for 50 gigalitres of desalinated water for delivery by June, but water production cannot start until repairs are completed.

The plant was finished in 2012 but has sat idle since.

Aquasure chief executive Matt Brassington said in a statement the generators would only be needed if repairs to the cable took longer than expected.

The large, one-megawatt generators would operate 24 hours a day, seven days a week.

Some night-time lighting of the area would also be needed, and up to four fuel trucks would deliver to the site daily.

The Bass Coast Shire Council sought an urgent meeting with Aquasure about the emergency power plan.

Mayor Pamela Rothfield said residents were worried about polluting emissions and loud noise from the generators.

“We’ve seen other towns that have been subjected to massive pollution, and I think it’s awful that our community has to potentially suffer something like this.”

A decision about whether the generators are needed will be made later in the week.

Cr Rothfield said Aquasure had applied to the Environment Protection Authority for approval to use the generators.

“So they can’t switch on until about March 14 and they can only get approval to run the generators for 30 days,” she said.

The company maintained it does not expect to have to use the generators for any longer than one month.

Hyflux To Develop Three Desalination Plants In Saudi Arabia

Singapore-based Hyflux has signed an memorandum of understanding (MoU) with the kingdom of Saudi Arabia to develop three desalination plants.

The MOU has been signed by Hyflux’s subsidiary Hydrochem Saudi with Saline Water Conversion Corporation (SWCC), a state-owned utility, following a public tender.

As per the MOU, Hyflux will design, build, supply, test and commission three seawater reverse osmosis desalination plants, which will be located in Duba, Wajh and Haql along the Red Sea coast in the western region of the kingdom.

The combined value of the three plants is SAR687m ($183m) and each plant shall be designed to process about 16,000m3 of water per day.

The plants will be equipped with reverse osmosis membrane technologies that can convert seawater into drinkable water. Construction of the plants will begin once the contracts have all been finalised.

The MOU signing ceremony in Riyadh, Saudi Arabia, was witnessed by Saudi Arabia Minister of Environment, Water and Agriculture Abdulrahman bin Abdulmohsen Al-Fadhli, and Singapore Minister of Environment and Water Resources Masagos Zulkifli bin Masagos Mohamad.

These projects are expected to have a material financial impact on Hyflux pending finalisation of the contracts.

Hyflux is a Singapore-based company focused providing sustainable solutions particularly in the areas of water and energy. The company carries out operations in several countries in Southeast Asia including China, India, the Middle East, Africa and the Americas.

Doosan Lentjes’s new Integrated Waste-to-Water Process

Water division of Doosan Heavy Industries & Construction, Doosan Lentjes in South Korea, have developed a new Integrated Waste-to-Water Process (IWWP).

Much like thermal desalination units that off-take heat from co-located power plants, the process would direct steam from the incineration of municipal solid waste to be used in the seawater desalination process.

The company said that using the technology, around 300 tons of municipal waste has the potential to generate enough potable water for 100,000 people.

While the announcement lacked detail, Doosan is currently involved in both the thermal desalination market, offering both Multi-Stage Flash (MSF) and Multi-Effect Distillation (MED), as well as Reverse Osmosis (RO) membrane-based water filtration.

Gerhard Lohe, director of waste to energy at Doosan Lentjes, said: “Our advanced IWWP can be optimised for either a higher energy generation or a higher water production – depending on respective requirements.”

This is not the first time the solid waste and desalination markets have crossed paths.

Last year WWi reported that EPC company Hitachi Zosen Corporation was going to combine its solid waste and water desalination businesses for the Middle East market.

Meanwhile Singapore engineering company Hyflux is diversifying from traditional desalination to the solid waste to energy market with a partnership to develop the TuasOne project.

Sodium Hydroxide For Thermal Energy Storage

Researchers have been testing a theory that Sodium Hydroxide could be used to store solar energy collecting during days or seasons as a form of ‘natural battery’.

Quite simply the hypothesis stems from pouring water into a beaker containing solid or concentrated sodium hydroxide (NaOH) which results in an exothermic reaction – chemical energy is converted to heat.

Sodium hydroxide solution is highly hygroscopic and able to absorb water vapour and the condensation heat obtained as a result warms up the sodium hydroxide solution even more.

Empa researchers Robert Weber and Benjamin Fumey have been working for years to see could if this experiment be replicated on a scale capable of storing enough energy for a single-family household.

They used an insulated sea container as an experimental laboratory on Empa’s campus in Dübendorf – a safety precaution as concentrated sodium hydroxide solution is highly corrosive. This failed. Instead of flowing correctly around the heat exchanger, however, the thick sodium hydroxide solution formed large drops. It absorbed too little water vapour and the amount of heat that was transferred remained too low.

They tried again and the test was a success. They used a viscous storage medium to trickle along a pipe in a spiral, absorb water vapour on the way and transfer the generated heat to the pipe and found the optimum temperatures: 5°C to 10°C is required to drain the store.

While replenishing the store, the 30% “discharged” NaOH solution trickles downwards around the spiral pipe. Inside the pipe flows 60°C water. The water from the solution evaporates; the water vapour is removed and condensed. The condensation heat is conducted into a geothermal probe, where it is stored. The sodium hydroxide solution that leaves the heat exchanger after charging is concentrated to 50% again, i.e. “charged” with thermal energy.

Fumey explains that the method enables solar energy to be stored in the form of chemical energy from the summer until the wintertime. “And that’s not all: the stored heat can also be transported elsewhere in the form of concentrated sodium hydroxide solution, which makes it flexible to use.”

As more research is conducted in this area, there will no doubt be questions and speculation about how charging sodium hydroxide could be used to power thermal desalination in places with seasonally low solar irradiance.

What do you think about the initial findings? Do you think this method is scalable to work at a level that could work for small communities? Do you think it would be cost-effective?

Finalists Announced For Singapore’s 5th Desalination Plant

Keppel Infrastructure, Sembcorp Utilities, Tuas Power and YTL Power International are the four finalists shortlisted by PUB (Singapore’s water authority) for a desalination project on Jurong Island.

The proposals were for the design, build, ownership and operation of a plant that can provide 137,000 m3 per day by 2020. Each proposal sets out a tariff structure and terms and conditions for supply and purchase of desalinated water under a 25-year water purchase agreement.

Keppel was awarded the Marina East project at the beginning of the year which has the same capacity as the proposed Jurong Island.

Singapore currently has two desalination plants in operation, SingSpring and Tuaspring, which operate with a combined capacity of 100 mgd. Both plants use reverse osmosis for its desalination, which uses 3.5kWh/m3.

One of PUB’s goal is to halve the desalination energy used in the future. This will no doubt be a feature that the finalists have factored into their designs.

The Tuas plant is testing and planning to scale up an electrodeionisation facility that will produce 38,000m3/day.

Here is a diagram of how the other existing plant SingSpring operates. It has a pre-treatment process where suspended particles are removed before RO.

Israel Gets Wake Up Call For Its Bets On Desalination

There’s no doubt that Israel is the global poster child for seawater desalination, but that reputation could be starting to turn for the wrong reasons.

It’s time to take an orthogonal viewpoint on how this apparent ‘revolution’ is posing a major threat to the health of the people and environment.

Of course, Israel has relieved and empowered it’s people with their investment in desalination. Residents of one of the driest places on earth freed from chronic droughts by processing the water on their doorstep.

Israel may have gravely overlooked two long-term problems in favour of this solution. The county is set to consume 582 million cubic meters of water annually through it’s current five plants, increasing it’s output by five more plants by 2025.

A few weeks ago, we posed questions about whether Saudi Arabia had actually taken any measures to deal with brine. There was no response from national science institutions. NASA however, were kind enough to get back to us and confirm that nothing could be tracked from space and on-the-ground efforts were required.

Despite the obvious advantage of using potable water for agriculture and combat droughts there are number of significant health threats on the horizon.

Magnesium Deficiency

Israel is bracing itself for an increase in myocardial infarction (heart attacks) in areas and added reliance on magnesium-rich fertilisers.

Prof. Yona Amitai, a public health expert, warned that “more studies be done to examine the possibility of adding magnesium to the water. ”

Hila Gil, director of the desalination division in the Water Authority added “It might cost hundreds of millions of shekels a year. It could affect the price of the water, and we would be the ones who’d have to explain to the public why the prices have risen.”

Israeli isn’t a poor country, but what can it budget for running these experiments and rolling out a solution? Could this be more costly than effective R&D at an earlier stage?

Wastewater

Gil began to express concerns with the high-concentrated brine ‘treated with chemicals’ (likely purified through Lime, CO2 & Soda…) that is being pumped back to sea.

A study is currently underway at the Israel Oceanographic and Limnological Research Institute in Haifa. Dr. Jack Silverman, one of the researchers involved, says they are trying to assess what effect the high salt concentrations will have on wildlife at the bottom of the sea bed.

“Along the bottom, there are very important processes that go on with respect to the survival of the ecological system. Our working assumption is that the concentration may influence these processes and, according to the initial findings, there is an effect”.

None of this should be surprising. It’s a positive sign that senior officials and locals are becoming more savvy to some of the long term risks before the next five plants are built.

It is a disappointing blow for desalination in general, as it will likely be the ‘scapegoat’ in the face of any disaster, whilst poor planning and execution is rather the culprit. We’re still at an infantile phase with this desalination in terms of global, scalable solutions and it would be catastrophic for public attention and funding being drawn away from the need to ‘make it better’.

I do hope the results of the mentioned studies make as many headlines as the utopian ones have, spurring nations that are planning large bets on seawater desalination to consider innovative ways of mitigating the very well known long term consequences.

Teenager Discovers New Water Desalination Method?

A story about a Portland teen discovering a new desalination method has been doing the rounds. It appears copied and pasted across 100s of media sites and is incredibly light on details.

The article states that a high school student, Chaitanya Karamchedu, approached the desalination from a different point of view,  claiming that  he focused on the 90% of water that’s not bonded to salt particles and used a highly absorbent polymer to isolate this.

Tracking down his paper we’re able to shed some more light on it:

It is possible to use such hydrophilic polymers to desalinate water without thermal or electrical energy. Water that was not bonded with salt, bonded with the starch grafted polyacrylamide to form a hydrogel, effectively isolating it from the salt water.

The extracted water’s conductivity was comparable to fresh water indicating that the salts have been separated. The average conductivity of the resulting water was 306.32 μS/cm, comparable to the conductivity of 200 μS/cm for the reference distilled water used.

That this approach has promise in mitigating desalination pre-treatment and post-treatment problems. Mass and conductivity analysis confirmed that the extracted water had a total dissolved solids concentration of 513 mg/L, (WHO guidance is <600 mg/L) compared to 35,000 mg/L for seawater. The concentration of sodium in the extracted water was 25.8 mg/L (compared to 10,500 mg/L for seawater) and that of chloride was 36 mg/L (compared to 19,000 mg/L for seawater). The corresponding EPA secondary concentration levels (aesthetic standards) for sodium is 20 mg/L and for chloride is 250 mg/L.

Chaitanya won a $10,000 award from the US Agency for International Global Development at Intel’s International Science Fair and second place at MIT’s TechCon Conference where he won more money to continue his research.

The winning project at TechCon was a fluoride removal method – using mildly processed bauxite to remediate groundwater fluoride concentrations to the WHO’s maximum contaminant limit for safe drinking water (1.5 mg F-/L).

Although great commendation has been given to the student on an international level, existing research using hydrogels for desalination was published in 2006. Journalists seem to take a lacklustre approach when it comes to accurate report on ‘teen discovery’ story – I’m sure it’s getting plenty of clicks though!

Wood-Graphene Oxide Composite Increases Efficiency Of Desalination

Researchers from the Materials Science and Engineering School of Washington University in St. Louis released a publication today claiming to have an improved process for generating solar steam, thus desalination.

It involves introducing a bilayered structure made of wood and graphene oxide. The graphene oxide is deposited on the micro-pours of wood providing a broad optical absorption and high photothermal effect. This results in rapid increase in the temperature at the liquid surface.

Although the wood serves as a thermal insulator to confine the photothermal heat to the evaporative surface, it facilitates the efficient transport of water from the bulk to the photothermally-active space

Because of this structure and the collective properties each component, the composite exhibited a solar thermal efficiency of ~83% under simulated solar excitation at a power density of 12 kW/m2.

Researchers claim that their structure is highly scalable and cost-efficient, though this statement begs to question – who doesn’t make this claim anymore?

Given the market price for a single gram of graphene oxide is $400 I am interested to know how this can be considered ‘highly scalable’ and ‘cost-efficient’!

Mexico Refuses Drought Stressed California A New Source Of Water

Baja California state’s infrastructure minister says the under-construction Rosarito desalination plant will not supply San Diego.

The plant about 15 miles south of San Diego is being built and is to be operated by Suez. It’s the first of two proposed plants that will collectively produced 150 million gallons a day, enough to supply more than 300,000 homes on both sides of the Mexico-US border.

The plans were initiated as a sort of partnership between Mexico and America but the US was criticised as if this collaboration was an effort to dodge domestic environmental reviews and legal challenges.

This could fire up the long-standing dispute between both countries over the Colorado River where Mexico are protected by a 1944 treaty.

The river feeds several U.S. states and northwest Mexico. The assistant director for binational affairs at Mexico’s National Water Commission, Jose Gutierrez, who says “the treaty carries great significance in our country. We have to protect it fiercely.”

Do you think Mexico are right to take this stance given the current US administrations controversial plans?


Power plant in Playas de Rosarito where the desalination plant was proposed to be constructed next to so that the vast amounts of water used at the plant could be used for desalination.

Solar Desalination System Reaches 80% Efficiency?

Nanjing University, in the capital of China’s eastern Jiangsu province, has reported a solar desalination device that has an efficiency of 80%.

The last major milestone was made by Australia’s solar researchers who converted over 40% of the sunlight hitting a solar system into electricity, that was the highest efficiency ever reported. This came from the institution where Martin Green, dubbed ‘the father of Photovoltaics’ resides as Scientia Professor.

This new process is supposedly made possible by a confined, two-dimensional water path. Also, due to minimised heat loss, the high efficiency of solar desalination is independent of the water quantity and can be maintained without thermal insulation of the container.

A foldable graphene oxide film, fabricated by a scalable process, serves as efficient solar absorber, vapour channel and thermal insulator. The graphene oxide film is not in direct contact with bulk water, but is physically separated by a thermal insulator (polystyrene foam) to suppress parasitic heat loss. A 2-D water path is enabled by a thin layer of cellulose wrapped over the surface of the thermal insulator.

Graphene Oxide Film

The entire structure can float on the water surface, with only the bottom side of the cellulose in direct contact with bulk water, so an efficient water supply to the absorber on the top surface is enabled by a 2-D surface water path within the cellulose pumped by capillary force.

Whilst the report sounds impressive, are the claims scientifically valid given the energetics of solar? Please comment with your thoughts!

The full paper can be accessed here.