Juice producing companies requires significant consumption of water and chemicals (detergents & disinfectants) for cleaning and disinfection of facilities, leading to a high volume of waste water.

AINIA technology center, Spain, has been investigating the development of cleaner post-harvest techniques applied to the citrus industry since 2010. This research has focused on three interrelated areas: hygiene equipment, product conservation and water treatment.

Laboratory and pilot work that has been completed concludes that the technical feasibility of developing systems for post-harvest treatment based on the use of ozone and ultraviolet light, is as effective as conventional systems,
and reduces the use of fungicides. Advanced oxidation of water discharged will regenerate the water that was used in treatments for possible reuse. Ozonated water used for cleaning juice tanks is as effective as the use of chemical disinfectants, but using a lower consumption of disinfectant and water.

Ozone is a powerful oxidant with a broad-spectrum bactericidal effect which does not generate chemical waste since it degrades rapidly to give oxygen, and ultraviolet light (UV) is a germicide that has no residual effect nor secondary.

Thus the use of advanced oxidation, has a high potential to become a useful tool for the citrus industry, mainly for its environmental benefits compared to traditional chemical fungicides used in post-harvest treatments or traditional disinfectants used in cleaning facilities.

This project is taking place in the ‘Plataforma Solar de Almería’ PSA. To carry out the different possibilities of the biological process, the PSA research team is now starting up a pilot plant provided with activated sludge and moving bed biofilm (MBBR) in a combined SBR reactor.

Emerging pollutants like pharmaceuticals, personal care products and pesticides are of increasing interest to governments around the world that are concerned about the impact of these contaminants on aquatic life as well as drinking water for human consumption. Current waste water treatment processes can not remove some of these contaminants from water.

Water Innovation Project funding in York includes the Lake Simcoe/The Regional Municipality of York Pilot Plant, which will include pilot testing of advanced oxidation for removal of micro pollutants from municipal waste water in collaboration with the University of Toronto. Advanced oxidation technologies have been shown to effectively remove various micro pollutants from water including pharmaceuticals, personal care products and pesticides.

The process calls for the raw sewage flows into a large screen to remove major solids, then into a tank where bacteria eat more solids, then into what’s called a “clarifier” where more solids separate from the water, and then into an oxygen-free zone that further removes solids. The wastewater next gets filtered through sand. This is followed by advanced oxidation process (AOP) using ozone and peroxide. After AOP, the wastewater will be sent to membrane filtration and finally ultraviolet treatment.

Construction is planned to start in about a year.

From 1987 to 2009, the Air Force was pumping out polluted groundwater in this area and running it through an air-stripping system to remove contaminants. In 2009, it switched to what’s known as advanced oxidation form of treatment, in which hydrogen peroxide and ozone are injected into pumped-out groundwater to destroy TCE, 1-4 dioxane and other toxic chemicals. Ozone peroxide is more effective and uses less energy than air stripping.

The topics covered in the conference included ozone generation, disinfection, drinking water purification, bromate formation, advanced oxidation among other topics.

The process combines ozone and hydrogen peroxide to produce the hydroxyl radical, the most powerful oxidant available for water treatment. A joint development project now being conducted by Teijin and PUB, Singapore’s national water agency, has demonstrated that the process significantly reduces persistent pollutants such as pharmaceutical residue and endocrine-disrupting compounds.

The water-soluble organic solvent 1,4-dioxane dissolves numerous organic materials, making it suitable for a wide range of industrial applications. However, the World Health Organization’s International Agency for Research on Cancer has classified the solvent in category 2B (possibly carcinogenic), and in 2009 Japan’s Ministry of the Environment set the standard for 1,4-dioxane in wastewater at 0.05mg/l or less.

Both biologically and chemically stable, 1,4-dioxane requires the use of special degrading bacteria for biological treatment. Adsorption is difficult in treatments that use activated carbon, and the substance is hard to break down even with oxidation treatments that use ozone. In view of the extreme difficulty of treating 1,4-dioxane, the Japanese government is carefully considering the introduction of discharge regulations in the near future.

Scheduled for completion in 2014, this project will increase the treatment capacity of the GWRS by 31,000 acre-feet per year. GWRS, the largest advanced water treatment facility of its kind in the world, takes highly treated wastewater and purifies it through membrane filtration, reverse osmosis, and advanced oxidation using ultraviolet light (UV) and hydrogen peroxide. Advanced oxidation processes like UV/peroxide produce a powerful oxidizing compound called the hydroxyl radical. Hydroxyl radicals are capable of destroying virtually all organic compounds found in water including dangerous micro pollutants from pharmaceuticals, personal care products and pesticides that may not be removed by other treatment processes.

This highly purified water will be percolated into OCWD’s groundwater basin to supplement its drinking water supplies as well as to augment the seawater intrusion barrier, which prevents seawater from contaminating the groundwater. The GWRS has a secondary benefit of reducing the amount of treated wastewater discharged to the Pacific Ocean off the coast of Huntington Beach.

Ozone and hydrogen peroxide, when combined create a powerful oxidant called the hydroxyl radical. The overall process is called advanced oxidation. This process has been shown in numerous studies in both the US and Canada to remove a wide range of pollutants including pharmaceuticals, personal care products and pesticides.

The IJC’s Great Lakes Regional office is awaiting approvals to begin testing of advanced oxidation.