An effluent treatment system that eliminates the use of harsh chemicals in water treatment by using only natural resources, has achieved significant results at a water treatment project at the Holden Manz wine farm, in Franschhoek, says stainless steel equipment manufac- turer Vinquip Projects.

The company’s system is used to treat 3.6-million litres of effluent a year from the Holden Manz farm’s cellar, restaurant and hotel facilities.

“Impressive results were obtained by using the effluent treatment system on the Holden Manz farm. Chemical oxygen demand at intake was reduced from between 1 800 mg/ℓ and 3 000 mg/ℓ to between 50 mg/ℓ and 75 mg/ℓ,” Vinquip Projects states.

The pH at intake, which was initially between 2.5 mg/ℓ and 3.5 mg/ℓ, was corrected to between 7 mg/ℓ and 8 mg/ℓ,” says Vinquip Projects owner Laurent Desfarges.

In addition, the system is also used to treat 6.5-million litres a year of dirty water at the Milnerton Estate Helderzicht Cellar, in Stellenbosch.

Vinquip Projects developed the effluent treatment system specifically for the wine industry where dirty water needs to be treated, as the disposal thereof on farm fields creates underground pollution.

“The main benefit of the system is that it produces recyclable water. It is also ecological, 100% natural and the water can be reused during times of severe water shortages,” says Desfarges.

As no chemicals are employed, the system is suitable for use in other food industries, for example, in milk and beer production.

“In future, we would like to make the system available for housing developments in remote locations,” reveals Desfarges, who developed the system in 2006.

The system treats water by stripping the effluent of its sand or soil content by using a sand trap, which removes the sand through settlement. An auto- matic fine-mesh grit-removal process is installed at the end of the sand trap and the solids are fed into a container using gravity.

The effluent is then transmitted into an aeration tank, where the organic matter will undergo degradation by a fixed 15 kW aerator to provide the essential dissolved oxygen required for the treatment, Desfarges explains.

A concrete or reinforced clarifier will favour the effective separation of the liquid and the solids, as well as reduce the hydraulic retention of the effluent, yielding a quick separation.

To maintain the required sludge biomass, a pump is used to recirculate the sludge in the aeration tank. Excess sludge will be drawn out to a sludge storage tank, stabilised and prepared for disposal.

“The system is unique, as the biological treatment uses mostly oxygen and other natural products. In the face of a global water crisis, sustainable water treatment plants are becoming vital,” Desfarges stresses.

He adds that the treatment plant can also be used for the treatment of sewage, after which the treated water can be discharged safely into dams and rivers.

“Reusing and recycling water has become a global responsibility,” Vinquip Projects emphasises.
The theme of this year’s World Water Day, on March 22, was water and food security and it was stated that agriculture was by far the main consumer of fresh water.

“Unless we increase our capacity to use water wisely in agriculture, we will fail to end hunger and open the door for a range of other ills, including droughts, famine and political instability,” United Nations secretary- general Ban Ki-moon said on World Water Day.

Water covers three-quarters of the earth’s surface, but only about 1% is available as drinking water.
Globally, 664-million people still have no access to entirely hygienic water. Today, there are more people without access to tap water in cities than there were at the end of the 1990s.

Further, 2.5-billion people lack proper sanitary facilities, Ki-moon stated.

“Water sustainability and treatment is a necessity and continuous innovation in those areas is needed,” Desfarges states, adding that the agriculture sector can play a big role in conserving this precious resource.