PUR-ALL is the new technology developed by R&D team of CIE and MST Chemicals group. Thanks to Chemical Specialties and specific installations, the PUR-ALL process allows the final user to decide whether to use his waste water treatment process to dump the final purified water or to use it for irrigation or to reuse it in the finishing lines.
The plant realized by CIE gives the maximum flexibility thanks to a special construction and specific units to accept different chemicals specialties able to guarantee a final waste water quality. The cost per m³ of treated water is extremely cheap if European standards are respected; instead, if restricted local limits are present, the use of Chemical Specialties is necessary.
In case of Zero Liquid Discharge (Z.L.D.) plant version, the running costs are cheaper than the ones of any other existing technology and also in terms of capital costs, the installation of a new PUR-ALL plant, is approximatively 30% cheaper than current Z.L.D plants. Figure 1 shows the characteristics of PUR-ALL process including flow-diagram and application on anodizing and painting lines.
The process has been studied and developed to depress by precipitation any pollution elements: aluminium, sulphates, fluorides (if present), phosphates (if present) and chemical oxygen demand. The precipitation happens in two steps: in the first step, sulphates, fluorides and phosphates precipitate together with part of aluminium oxides. This happens thanks to a combined action of lime and a balance blend of inorganic oxides of Ca, Al, Fe, Si and to an oil and organic absorption specialty; in the second step, after sludge separation, a neutralization action leaves the possibility to remove excess of Al, Fe, Si and Ca that precipitate again as sludge. After sludge removal, the water is sent to a polishing filter where excess of salinity is removed.
PUR-ALL process is successfully used in an anodizing line on the acidic parts to remove aluminium and sulphates (see Fig. 2). Also this process generate perfectly suitable water being used istead of fresh water in the alkaline section of anodizing line. This technology, while strongly reduce sulphates until any possible requested limits, give the fantastic result to reduce 50% of water consuption without any negative effects.
PUR-ALL process is successfully used on painting line equipped with acidic pretreatment cycle (see Fig. 3). In that case, the water recovering could reach the 100% (if chemical specialties are correctly used) and the resulting water can be reused in the same line realizing a full Z.L.D. process.
PUR-ALL ZERO ZERO advantages
- No I.X unit to be used
- No U.F. or R.O. required
- No Evaporator
- No Liquor to dump
- Minimizing Running costs
- Maximum flexibility
Case History: Aluminco
Three years ago, Aluminco, a Greek company, installed a vertical paint line for approx. 3 T/h of aluminium Extrusions. This line has been equipped with a Z.L.D. plant based on Zeolite absorption technology called "geothermic technology". One year later, considering the bad results, the line has been revamped by a supplier of Z.L.D., but the result was negative again. Therefore, CIE has been requested to install an updating Z.L.D. line using PUR-ALL technology.
The new Z.L.D plant is successfully working and satisfying with customer's requests. The result is 97% of water recovery and reuse with the high-quality water and conductivity less than 50 ppm pH = 7,5.