Hydrodemolition
Hydrodemolition is the removal of damaged and/or degraded concrete through the use of either high or ultra-high pressure water jetting activities by manually hand operated lances or remotely operated programmable robotics.
With over 20 years of experience treating alkaline waters with solids held in suspension, Siltbuster has developed tailor-made systems specifically designed to process the harmful blast water created as a by-product of the hydrodemolition process which exhibit these same characteristics, treating them to an acceptable environmental compliance level prior to discharge.
Our solutions are industry renowned, cost-effective and easy to operate. We also know that space on site is often minimal and at a premium, and our systems always reflect this through a small footprint/high treatment capacity ratio.
Why treat hydrodemolition blast waters? Unfortunately, highly alkaline waters (> pH7) are not given the same instinctual respect and consideration when compared to strong mineral acids. However, the very real reality is that caustic solutions can be as equally dangerous as their acidic counterparts and have the capability to have catastrophic effects on the natural environment and the ecosystems living within them.
If released unchecked; waters with an alkaline pH value can damage the outer surfaces, skin, eyes and gills of aquatic life and can render certain species unable to dispose of their metabolic wastes. Concurrently, the rapid change to the pH in which they inhabit can cause “pH shocks” – all of which places huge amounts of stress and strain on the organisms within which are not suited to functioning within this alkaline setting. Finally, with the pH scale being logarithmic in measurement – dilution is not the solution – and active water treatment systems are the only practical and economical answer to the problem.
Traditionally alkalis would be treated using strong mineral acids (sulphuric, hydrochloric or nitric) or organic acids such as citric. These chemicals however need careful handling (specialist training and PPE) and are difficult to dose correctly from a practical process perspective, with the risk of overdosing and acidifying the waters a very real and strong possibility. Furthermore, these reagents often introduce a secondary pollutant through the addition of their corresponding anion when fully dissolved in water – often exceeding acceptable limits imposed by the EQS.
Siltbuster’s systems use vapour carbon dioxide to neutralise hydrodemolition blast waters which have a number of advantages, namely:
- It is impossible to reduce the pH below 5.6. However, in practice it is difficult to lower the pH below 6.1 and therefore the risk of discharging the water with a pH that is lower than pH 6 is virtually eliminated.
- Automatic pH adjustment system ensures that the correct amount of CO2 is introduced every time removing the possibility of human error and manual dosing.
- Carbon Dioxide is much safer and easier to handle and store.
- Carbon Dioxide is readily available and virtually all industrial gas suppliers stock either 34 kg cylinders, or in bulk cryogenic storage tanks.
- There is no risk of exposing operators to acid burns.
- Carbon Dioxide is an extremely cheap option when compared to other neutralizing acids / reagents.
- CO2 does not affect COD levels unlike citric acids
Siltbuster PMPU20
The Siltbuster PMPU20 is an integrated solution which comprises two dedicated reaction tanks and integral lamella clarifier for the multistage manipulation of pH levels and removal of suspended solids. This sequential treatment philosophy not only reduces the amount of reagent required per cubic metre of water, but also reduces the hardness/alkalinity and improves the treated water quality upon discharge.
The PMPU20 has a typical continuous operating range of up to 20m3/hr and also incorporates its own onboard peristaltic slurry pump controlled via an asymmetric timer for the disposal of the captured slurry or for its recirculation where users have a High-Density Sludge (HDS) so as to minimise underflow removal costs. The system can be configured to work with vapour carbon dioxide should an alkaline value be detected or used in conjunction with caustic solutions should the feed to be treated have an as received acidic value. View the Siltbuster Hydrodemolition range Profile Drawings.
Typical applications: Precipitated Solids Removal, High pH Water, Low pH Water, Hydrodemolition
Hydrodemolition (HD) Unit
The Siltbuster HD (Hydrodemolition) unit is a compact, battery operated, easily transportable and effective solution for treating high pH, sediment laden blast water from lance cutting hydrodemolition operations – designed and developed in direct response to requests and feedback from hydrodemolition contractors across the UK.
Our HD unit is ideal for use on roadworks or on schemes where access is limited, such as multi-storey car parks, basements, etc.
The HD unit can operate continuously at flowrates of up to 5m3/hr and be powered from an external 110V power source or its own internal battery. Powered from its own battery, it is perfect for use in remote locations and short hydrodemolition projects without the need for a generator, additional lifting equipment and the associated costs. View the Siltbuster Hydrodemolition range Profile Drawings.
Typical Applications: Hydrodemoliton, Concrete cutting, Restricted Space Sites