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Report

Teaser, summary, work performed and final results

Periodic Reporting for period 2 - WATIFY (Up-scaling, demonstration and first market application of Hydrokemosâ€™ patented technology as the most eco-efficient and cost-effective solution for nitrate polluted water treatment)

Teaser

Summary

\"Problem 1: Permanent increase in freshwater water demand
Freshwater withdrawals have tripled over the last 50 years. Demand for freshwater is increasing by 64 billion cubic meters a year (1 cubic meter = 1,000 liters). Worldwide, agriculture accounts for 70% of all water consumption, compared to 20% for industry and 10% for domestic use. In industrialized nations, however, industries consume more than half of the water available for human use. Some key aspects that will contribute to increase the water demand in the future are:
- The worldâ€™s population is growing by roughly 80 million people each year.
- The production of biofuels has also increased sharply in recent years, with significant impact on water demand. Between 1,000 and 4,000 litres of water are needed to produce a single litre of biofuel. In general water demand of industrial use will be one of the categories that will increase the most.
- Energy demand is also accelerating, with corresponding implications for water demand.

Problem 2: Nitrate contamination in groundwater in Europe
Nitrogen fertilizers are applied extensively in agriculture to increase crop production, but excess nitrogen supplies can cause air, soil, and water pollution. Arguably one of the most widespread and damaging impacts of agricultural overapplication of nitrogen fertilizers is the degradation of groundwater quality and contamination of drinking water supplies, which can pose immediate risks to human health.
According to the latest European Commission report there is a high and stagnant level of nitrate concentrations in groundwater. The general trend in nitrate concentrations in groundwater when comparing the first (1992-1994) and second (1996-1998) monitoring exercise is summarised as \"\"stable to increasing\"\".\"

Work performed

During the Watify project, Hydrokemos has up-scaled, developed and contructed four full scale prototypes of a revolutionary system (Electrodenitrification) to purify and remedy water contaminated by nitrates adapted to four different industrial applications

Electrodenitrification process is based on electrochemical reactions converting inorganic nitrogenous species into nitrogen and oxygen. Denitrification cells consist in Iron cathodes and Titanium anodes electrically connected. AC is transformed to DC using a power rectifier that supplies the required energy to reduce inorganic nitrogenous species concentration in contaminated water.
The process is totally innovative against best available techniques in nitrate removal (BATs) because they are based on the separation principle while Electodenitrification converts the contaminants into air.
Technologies, such as reverse osmosis, ion-exchange membranes or electrodialisys, concentrate the inorganic nitrogenous species in a liquid current which requires its treatment after the process.
There is an also alternative process that reduces biologically the N-based contaminants. The main drawback of this technique is its highly dependence to environmental conditions. Few changes on them have a strong impact over the system productivity.

The project permitted to stablish several collaborations with industrial companies affected by inorganic N-based contamination. Among them, the most beneficiary agreement signed was with Girona public administration.
In the first period of the project, HydrokemÃ³s (F1) confirmed the location and capacity of each of the fourth prototypes.
Furthermore waters coming from each of the locations where prototypes were going to be locatedwere used in laboratory tests to define operation conditions and the electrodes design both in purification and remediation prototypes.

Once validated the experimental results, Hydrokemos S.L. staff performed the prototypes according to the end-user requirements. Operational conditions differ significantly in each application because they depend on the inlet water characteristics. In some cases, usually for potabilization plants, it is required a conditioning step before the denitrification process.

In the second period of the project, the constructed prototypes, adapted to each application have been operating in each location during at least four month, to be able to determine in each case the efficiency of the process, obtain the water quality results of the outlet water and the operating costs in each case.

During the operation of each of the prototipes, operation conditions have also been adjusted in order to get the optimum results

Final results

Electrodenitrification compared to best available technologies (BAT) which are: Reverse Osmosis, electrodialysis, ionic exchange resins and biodenitrification processes.

We expect to reach our commercial and business goals thanks to the significant novelties that electrodenitrification brings compared to available solutions. Currently, best available technologies are based on separation and not removal. They separate nitrate and other ions of the water in a non-selectively way producing that approximately a 20% of treated water reverses into a toxic and hazardous waste. Only biodenitrification, like the electrodenitrification, closes the nitrogen cycle.

Both technologies, electrodenitrification and biodenitrification, allow closing the nitrogen cycle again, converting nitrates in air, nevertheless biodenitrification is slow and very sensitive to temperature. On the contrary, electrodenitrification is cheaper, does not require organic matter and the machinery (and consequently investment) is significantly lower.

Besides not generating waste of difficult and expensive disposal, electrodenitrification, has a total cost savings (investment and exploitation) of around 50% compared to BAT. In this context, the advantage for customers or for suppliers of drinking water or wastewater treatment is clear.

To summarize, Electrodenitrification technology could become the best available technology in the near future because it takes several advantages from the current technologies in the market. These ones are:
Electrodenitrification technology converts the inorganic N-based contaminants into air which is non-aggressive to the atmosphere.
It does not produce any sub or by-produce at the end of the process. Other techniques require a post-treatment increasing the operational costs.
Whole waterbody is treated during the process while other techniques can only achieve 80 â€“ 85% of the total amount.
From the economical point of view, its operation and investment costs are very competitive in front of best available technologies at the market.

The electrodenitrification technology developed by Hydrokemos, and scaled and operated with success in the Watify project, offers a clean cost-efficient alternative to remediate nitrate polluted water with the exposed advantages with respect to the best available technologies for nitrate removal, which are Reverse Osmosis, electrodialysis, ionic exchange resins and biodenitrification processes.