An efficient saving
2015 was arguably a watershed year for CIE, the Italian water treatment company for metal finishing lines. With environmental issues and cost saving at the top of the agenda for many within the metal packaging industry, the introduction of its ZLD (Zero Liquid Discharge) technology is set to provide a solution to the supply and discharge of water.
“ZLD technology allows plants to recover and reuse its water,” explained Franco Falcone, CIE’s general manager. “Where the installation of lines of aluminium cans in countries where the supply and discharge of water is a problem, it makes it essential to apply closed circuit water purification technologies for their total reuse. The water can be totally reused on the same washer and this technology is applied to several lines in many aluminium finishing fields.
“An example of the success of ZLD was Bevcan’s new aluminium can line in Lucanda, Angola. Attention to the environment and reduction of water consumption was an essential motivation for Bevcan and since June, from when the plant has been active and fully functional, ZLD technology has resulted in the recovery and reuse of more than 98 percent of the water from the washing machines.”
TECHNICAL KNOWLEDGE OVER A COMMERCIAL MINDSET
Excellence within the water treatment industry hasn’t happened overnight for the Italian-based firm. Since 1980, CIE (Compagnia Italiana Ecologia) has been operating as a waste water plant project and manufacturing company for metal finishing lines using water for cleaning, etching and coating all kinds of metals (CRS, HDG, EG, aluminium and alloys). More than 500 plants have been installed by CIE both in Italy and the rest of the world. Recently the company celebrated its 35th anniversary and the company can boast of an impressive reference list across the world including work with Pepsi in Iraq in 2008 and Can-Pack in the United Kingdom in 2013. Falcone himself has been in the water treatment business since 1976; that’s a strong track record which appears to be paying dividends.
“I am a chemist by trade and that really is our business ethos,” said Falcone. “I have been technical manager for over 20 years and other staff also have extensive knowledge of the industry. We are a strongly technical company; we place high value on extensive technical knowledge and expertise rather than a commercial mindset. Seven percent of our expenditure year-on-year is purely for research and development.
“We pride ourselves on being an Italian company dedicated to metal water treatment; we are chemists who understand the purification process. We have more than 30 years experience in design, development, manufacture and installation of water and waste plants specifically dedicated to metal finishing lines; it’s a track record we’re immensely proud of.
“80 percent of our business is dedicated to aluminium cans lines and we have an impressive customer list including Rexam, Ball and Crown amongst others.”
‘PURAL’- THE MOTHER OF ALL TECHNOLOGIES
The success of ZLD itself is certainly attributed to the technologies involved being skilfully applied thanks to the knowledge of CIE’s staff on water treatment processes. Treatment success is said to be due to the reverse osmosis specifics calibrated on customers’ wastewater data and to the process ‘Pural’, which can reduce sulphates and fluoride pollution. The tests and experiments carried out are said to have demonstrated the applicability of ZLD systems even in complex situations, both from the point of view of the quantities and from that of the pollutants.
“Pural technology is the mother of all technologies,” said Falcone. “One of the main problems of purifying water for anodising lines is respecting sulphate limits. Anodising plants drastically reduces water consumption, but very often these cannot be used otherwise the sulphate levels cannot be respected.
“Pural technology minimises fluorides, sulphates, the chemical oxygen demand (COD) and aluminium. Around 90 percent of sulphates are eliminated so that the water is practically sulphate-free and can be sent to the alkaline section to substitute 100 percent fresh water. This technology can also be applied to waters coming from coating lines, from which it also eliminates the fluorides. This results in two advantages: the resulting volumes of water used are at least 50 percent less than with traditional treatment and this water can be sent, without any limitation, both to sewers or used for irrigation. As a result, a plant using ZLD will not have a need to dump water.”
Water saving is obviously an attractive aspect of ZLD technology. A number of high profile plants have chosen to adapt CIE’s form of ZLD including Metra in Italy and Zanussi Electrolux in Hungary. It is however the case study of Bevcan in Angola that offers the most telling evidence as to the validity of this technology.
“In the first 100 days of work with ZLD, Bevcan Angola has obtained savings of more than 24000m3 of water and thanks to cogeneration, there have been zero energetic costs. Two other ZLD plants, made by CIE, are in the process of assembly and start-up is expected shortly.”
THE FUTURE OF ZLD
For the uninitiated, cogeneration is where the final rejects are recovered and sent back to the cycle, thanks to a multi-effect vacuum evaporator powered by heat. This leads to no energy costs and comparable budgets to sewage treatment plants. This attraction budget-wise is obviously a positive, but there are also a number of practical reasons as to why ZLD is beginning to look favourable for plants according to Falcone.
“Practically, ZLD makes sense. With a number of future emerging markets, many of these countries have restrictions on the limits of water discharge. The likes of India and Africa have strict legislation and this means attention to the environment is absolutely essential for water purification; this of course opens up many opportunities in developing markets where metal packaging is starting to develop at considerable rates.”
With the rise in emerging markets, it is no surprise that CIE’s forecasts for future ZLD plants look particularly promising. Falcone is keen to stress this point when surmising:
“The future has certainly begun. Forecasts of CIE’s study centre state that, within the next five years, more than 50 percent of the treatment plants for aluminium cans will use some sort of ZLD technology. We predict that in 10 years, 90 percent of all ZLD plants will have zero percent water waste.”
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