Perdeberg Winery appointed A2V to design and supply a water treatment plant to treat water from the winery’s storage dam to SANS 0241: Class 1 for drinking water.
The dam water comprises mainly water from the Berg River Irrigation Scheme and is supplemented with rainwater and borehole water during the wetter winter months.
A2V proposed a system comprising the following key elements:
- coagulent dosing (Ultrafloc U3800)and settlement to remove the majority of suspended particuates (turbidity), dissolved organic carbon (DOC) and color.
- alkalinity adjustment to reduce the treated water’s corrosive potential.
- sand filtration
- carbon filtration to remove any remaining DOC and odors
- disinfection by chlorine dioxide
The inlet buffer tank and chemical make-up tanks and filter shelter.
Chlorine dioxide was recommended for disinfection over other disinfectants for a number of reasons:
- No formation of chlorinated byproducts as a result of disinfection and no free chlorine, chlorate or chlorite residuals in the treated water.
- Current literature reports that chlorine dioxide does not produce any chlorophenols – the precursor to TCA (trichloroanisole) formation.
- Effective for the control of biofilm as there is no resistance building from microorganisms
- No pH limitations on disinfection capability.
- Its disinfectant (sterilisation) capabilities are not diminished at all in the presence of fats, oils, proteins, body fluids etc. because it has very selective and very few chemical reactions.
- It is highly soluble in water, therefore, it has a long-lasting residual which reduces the potential for cross infection or re-contamination.
- It is a broad spectrum, fast acting disinfectant, effective against a wide range of bacteria, spores, fungi, and viruses at relatively low concentrations and short contact period.
- It is colorless, has a mild medicinal odour, low corrosivity to metals and the lowest acute toxicity rating from the EPA.
- High efficacy against E.coli, salmonella, listeria, aspergillus, penicillium, staphylococcus etc.
- The generator and dosing equipment are reliable and easy to maintain.
The chlorine dioxide generator and precursor soltuions
The plant was designed to supply 20 m3/hour of treated water with sufficient storage capacity to meet the cellar’s peak water demand of 500m3/day during the harvest season.
The plant was commissioned in August 2011, 7 weeks after the order was placed!
Perdeberg Winery Water Treatment Plant