Monday, February 29 2016
In response to numerous requests from borehole owners, A2V have developed a low cost system for removing iron from water in domestic applications.
Our system aerates the water prior to passing it through a specialized catalytic filter media which promotes the oxidation of iron, causing it to precipitate out into he media bed. The iron is then back washed from the filter in the same way as a pool filter is back washed.The catalytic media is highly effective and is unique in that it does not require regeneration, unlike many other iron removal medias on the market. Indeed, the media has a life span of up to 10 years if operated correctly, making electricity the only operating cost of the system.
Thursday, February 11 2016
The Mosstrich abbattoir in De Aar inthe Northern Cape utilizes the municipal water supply for all of its operations. However, the water has a hardness >350ppm and is also known to be shown bacterial contamination on occasion.
A2V were appointed to design a water treatment plant that would achieve the standards required by the National Directorate of Veterinary Services. The system implemented comprised the following processes:
- Zeolite filtration remove particulates down to 5um
- GAC filtration to remove possible organic contaminants such as pesticides
- Ion exchange softening to reduce hardness to less than 10ppm
- Disinfection by means on on site chlorine dioxide generator
- Booster pump installation to supply water to the abbattoir
The Sugarbird Manor Guesthouse and a number of residences on the Protea Heights farm all utilize water from two boreholes on the site. The water is exceptionally pure with the result that it is highly corrosive. This was leading the usual problems associated with corrosive water in domestic applications, namely:
- burst geysers
- laundry staining
- staining of sanitary ware
- pipe bursts
A2V designed and installed a limestone contact tank on the rising main from the borehole pumps to the main reservoir which resolved the problems previously experienced. Partial stabilization of corrosive water with limestone has been shown be the CSIR to be a low maintenance and cost effective method of reducing corrosion in plumbing systems.
A2V also implemented a disinfection program at the main reservoir to ensure that any bacterial contamination of the groundwater would be neutralized. This was achieved by using slow release Calcium hypochlorite tablets in a floating dispenser.
A2V were appointed to upgrade two Sulphuric Acid facilities at Protea Chemicals’ Killarney Gardens site. The existing facilities had been largely destroyed by acid attack over the years an had to be largely rebuilt.
A2V carried out the conceptual design in conjunction with Proteas’ engineers, after which A2V completed the structural design. and project manged the implementation of the project.
The bunds comprised reinforced concrete wall and floors lined in polyethylene anchor knob sheeting. The Anchor Knob Sheets(AKS) used were UV stabilised 3mm thick polyethylene sheets which are stubbed with knobs that are cast into the concrete walls and slab soffits. AKS can also be grouted onto floor slabs and walls of existing structures. Once the concrete is partially cured the form work is removed and the joints between AKS sheets are sealed by plastic extrusion welding.
This method of lining proved to me more cost effective than some of the epoxy lining systems considered, despite the more labor intensive nature of the installation.
Monday, August 24 2015
Albion Chemicals are manufacturers of of bleach and other cleaning products. Cape Town municipal water is used as the main ingredient for all of their products.
Albion were experiencing a high number of returns on their products due to ‘blow-outs’ of the product bottles. A number of water and product samples determined that the most likely cause for the ‘blow-outs’ was the presence of iron in the make-up water. Indeed, iron levels in the municipal supply were found at times to exceed 2mg/L and the SABS standard for drinking water.
The City of Cape Town uses ferric chloride as a coagulant on many of its water treatment plants. At times the process is not managed correctly and either excess ferric chloride is present in the water; or flocs are carried over from the settling process into the reticulation system.
A2V designed a filter system using a specialized catalytic media, designed for the removal of iron and manganese. The media acts as an oxidation catalyst causing the metals to precipitate within the media bed,consistently removed iron to <0.01ppm. It is also effective at removing arsenic, aluminium and other heavy metals.
The catalytic media uses an oxidation, adsorption and filtration process similar to Greensand and Birm, but to a much higher removal efficiency and significantly lower life cycle cost. The media lasts for 5 to 10 years and does not require regeneration. The entire process is simpler to operate and less costly to install than traditional iron removal systems.