Separating suspended solids from liquids before discharging to sewer or water course is a problem that construction companies have.
Aggravating the problem further is materials that won’t settle quickly. To overcome this obstacle Monmouth-based Siltbuster Ltd has standardised on innovative 500 and 600 series peristaltic pump technology from Watson-Marlow, ensuring that construction projects can continue without delay whilst meeting very strict environmental standards.
Siltbuster Ltd is the UK’s leading designer and manufacturer of mobile silt management equipment. The company has in excess of 60 silt pollution prevention projects, as far afield as the Orkney Isles and New South Wales, Australia.
The company’s core product, Siltbuster, is a range of liquid/solid separation devices designed for temporary use on construction sites to remove suspended solids/oil from water pumped from holes, excavations or surface run-off. The Siltbuster units have been developed to meet the increasing need to improve the environmental protection of water courses, groundwater and marine environments, and the process is now considered best practice for the management of dirty water pumped from construction sites.
However, it is not all plain sailing, as Siltbuster Ltd’s managing director Dr Richard Coulton explains: “Unfortunately we are never entirely sure what we are treating until we see it. On some jobs fine particles settle extremely slowly or not at all – so we have to help them settle faster via chemical conditioning techniques such as flocculation, coagulation or pH adjustment. We use Watson-Marlow 520 and 620 range of peristaltic pumps to help facilitate this process.”
Siltbuster Ltd previously used diaphragm pumps for chemical addition, but grit blocking the valves was a continual problem.
“Downtime in the construction industry is costly and we couldn’t afford any more pump failures, so we looked for an alternative pump type. The Watson-Marlow pumps appeared robust, reliable and importantly, foolproof. As mobile units, the Siltbuster systems need to be maintained on-site by construction workers who are perhaps not familiar with water treatment technology.”
With Watson-Marlow peristaltic pumps, nothing but the tube touches the fluid, eliminating the risk of contamination of the fluid or the pump. Fluid is drawn into the pumphead and trapped between the rollers and the track. As the next roller moves forward, the pocket of fluid is expelled and more is drawn in to the tube by the vacuum that is created. The complete closure of the tube gives the pump its positive displacement action, preventing backflow and eliminating the need for check-valves when the pump is not running.
The pumps, which often run 24/7, are ideal for slurries, viscous, shear-sensitive and aggressive fluids, and are easy to install, simple to operate and inexpensive to maintain.
The Siltbuster process, in contrast to conventional settlement tanks, stills the incoming water/solids mix and routes it upwards between a set of inclined plates for separation. Fine particles settle on to the plates and slide down to the base for collection, while treated water flows to an outlet weir after passing below a scum board to retain any floating material. The inclined plates dramatically increase the effective settling area of the unit, resulting in a smaller space requirement on-site and a process that unlike lagoons, is unaffected by wind disturbance.