Monday, June 11 2012
Perdeberg Winery Effluent Plant
Perdeberg winery is located outside Wellington in the Western Cape. it is one of the largest wineries in South Africa.
The original Effluent Treatment Plant (ETP) at Perdeberg Winery comprised the following elements:
- An inlet works with a channel auger screen for the removal of larger solids and two settling chambers for the removal of grit.
- A balancing dam to equalise the highly variable effluent flows and organic loads from the cellar.
- A raw effluent feed pump station lifts the effluent from the balancing dam into a contact tank where pH adjustment is achieved through the addition of lime.
- The bulk of the COD is removed by an anaerobic process comprising two stages; acid fermentation followed by methane formation. This is achieved in two anaerobic ponds through which effluent is recycled at a continuous rate to ensure proper mixing and pH control.
- An aerobic pond serves to polish the effluent from the anaerobic ponds from where it is discharged to an irrigation dam.
Unfortunately the plant had never operated satisfactorily due to a number of shortcomings in its design. A2V were approached for a proposal to identify and rectify these shortcomings. We determined that there were two main problems with the plant:
1. 1. Solids Removal
The existing channel screen and settling basins were ineffective. This led to an accumulation of non-biodegradable solids in the balancing dam and anaerobic ponds which has in turn led to:
– Reduced equalisation capacity
– Blocking and tripping problems with the Raw Feed Pumps.
– A reduction of treatment capacity in the anaerobic ponds where active biomass was largely been replaced by solids.
– Blocking problems in the interconnecting pipework.
2. Recycle Rate
The recycle rate measured on site was found to be inadequate which had the following negative effects on the process:
– Poor mixing in the active zone of the anaerobic ponds, leading to poor treatment.
– Due to lower flow rates in the pipe work, there was a propensity for solids to settle out which lead to added to the problem of numerous pipe blockages.
– The pH and alkalinity control was not as effective, which led to poorer performance and ultimately acidification (failure) of the anaerobic biomass.
A preliminary check on the plant hydraulics suggested that the current plant design was limiting the recycle rate that could be achieved.
A2V proposed a cost effective solution , making use of existing infrastructure as far as possible:
1. The existing auger screen was retained and refurbished with a larger aperture basket.
2. The equalisation pond was converted to a settling pond through the addition of a floating decanter.
3. The recycle pumps were refurbished with larger impellers and motors to achieve a higher recycle rate.
4. Bottlenecks in the interconnecting pipework were removed to facilitate higher recycle rates.
5. Scum baffles were fitted to the anaerobic ponds to prevent debris from blocking pipework.
The solution was implemented in a phased approach starting in January 2012. Immediate improvements in plant performance and operability were achieved after implementation.
Friday, June 08 2012
Aaldering Vinyards and Wines – Effluent Treatment Plant
Aaldering Cellar is a boutique cellar located in the Devon Valley, Stellenbosch. The cellar will process approximately 150 tons of grapes per annum from February of the 2012 harvest season. The ultimate future capacity of the cellar will be approximately 200 tons per annum.
Thursday, May 31 2012
L’Ormarins Water Treatment Plant
L’Ormarins Effluent Plant
Rust en Vrede MBR Effluent Plant
Thursday, March 29 2012
Perdeberg Winery Water Treatment Plant
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
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 equiment are reliable and easy to maintain.
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!