Automotive/Aeronautic/Metal industry (cars, trucks, planes, heavy machinery, components) faces increasing environmental requirements, especially on COD, metal removal and special molecules removal. Often residual metal levels, residual hydrocarbon or oil levels or surfactant content are a problem which traditional chemical or biological treatment plants cannot solve. Often a good and effective
treatment plant can no longer comply with new requirements, coming either from authorities or even from internal goals and strategy. Most often, operating costs for existing plants are extremely high.

Metal removal is easy as fast forward with electrocoagulation. Oils and emulsion removal also. No more huge chemical dosage, no more huge activated carbon adding, no more pH control up and down is required.

Introducing advanced oxidation systems to these operations is the key to solve these problems, either along with new treatment plants or just revamping/retrofitting existing ones. Very short paybacks on investment with these revamping are quite common.
Many companies use very expensive final or tertiary treatment procedures, like activated carbon adsorption, to try to solve these problems, most of the times unsuccessfully at a very high cost. VentilAQUA’s AOP solutions with electrocoagulation show the way to metal, oils and emulsion removal. No more huge chemical dosage, no more huge activated carbon adding, no more pH control up and down is required.

In recent years, the number, variety, and composition of synthetic chemical compounds have increased tremen- dously. Their use has influenced every aspect of modern life. A particularly widespread group of chemical com- pounds are phenolic resins (phenol-formaldehyde resins or bakelite). They have been reported to have high stability and high environmental toxicity. Additionally, carcinogenic properties can damage human health seriously. The phenol formaldehyde resin producing industries generate waste- water with a high concentration of organic matter. Such wastewaters are difficult to be treated by biological processes when the phenol is present at high concentra- tion. The reason is that it causes inhibition to the normal function of the microbial population.

These technologies combined allowed for the total removal of formaldehyde and consequently, COD and BOD with a 99% removal. With these results, operating costs decreased a lot because all wastewater was being directed to a hazardous waste management company that charged for the transportation and treatment of the effluent. Such advantages in the cost of operation and construction will have a considerable weight on the economic balance of the project, in global terms.

The key to overcoming these problems lies in oxidative pre-treatment, such as adding electrocoagulation (EC) process before a biological one. EC is an electro-chemical process that removes suspended, emulsified or dissolved contaminants from water using an electric flow of charge. It generates a direct flow of charge to free into the liquid the metal ions from sacrificial anodes that will remove undesirable contaminants.

Inlet parameters
COD – 200.000 mg/L FORMALDEHYDE - 120.000 mg/L

Outlet parameters
COD - 1000 mg/L FORMALDEHYDE - <120 mg/L

One of the most critical sources of environmental problems in any shopping center or mall is the food court, with its greasy waste waters. From a long term experience and survey, majority of malls and shopping centers have serious compliance problems with waters coming from grease traps. Grease traps are designed to retain waste waters for a period of time, generating bad odors and increasing organic loads that will
affect the downstream treatment plant, besides not com- plying with majority of reject limits for waste waters established by local authorities.

VentilAQUA brought to this process an advanced oxidation technology, using electricity, called electro-coagulation and electro-oxidation, which allows a more intense and efficient organic matter removal without chemicals, managing to reduce contamination to very low levels and allowing to use common multimedia filters with longer lifetime and to reuse these waters.

Under 1 year payback time with water consumption reduction, as about 90% of food court waste waters are recovered into flushing toilets, thus reducing dramatically water consumption in toilet rooms. Elimination of complex removal and trucking of liquid wastes and greases, highly loaded, and consequent extremely high cost.

Replacing standard or more sophisticated (although with limited performance) grease traps by chemical treatment units, with flotation devices (DAF), we manage to perform a proper chemical treatment to the waste waters, remove all solids, fats and greases, avoid bad odors, besides reducing drastically its organic loads, preparing these waters for a final disinfection and filltration which will allow them to be reintroduced into an internal feed line to flush waters and irrigation.