Here, Dr Richard Coulton, CEO of Siltbuster Process Solutions, the leading water treatment specialists, highlights the impact that effluent treatment problems are having on compliance and explains how the latest technologies can be used to improve the situation.
Through our role of providing effluent treatment equipment to the UK’s manufacturing community, we have gained a good sense of how wastewater treatment plants are managed.
Although they are frequently out of sight, we firmly believe they should be anything but out of mind, so wanted to better understand how and why companies prioritise, invest in and manage their effluent treatment plants.
To achieve this, we commissioned an independent study among the production directors and engineers responsible for over 156 manufacturing sites in the UK and the findings were very revealing.
Why investment in effluent treatment technology needs to be a priority
According to the study, 30% of companies had had a significant effluent treatment problem in the previous year which put their compliance at risk, with effluent treatment plant failure or breakdown the most common cause (31%).
A third of the companies questioned said investing in waste treatment plant is a priority, but 28% of production heads reported that their treatment plan is under invested in.
41% of the companies last invested in the plant more than five years ago and 23% more than 10 years ago. 15% believe this is because the Board is only interested in investing in new production lines; a further 13% say that effluent treatment is viewed as a peripheral area that senior management doesn’t want to think about.
The study went on to suggest this is symptomatic of the low profile which effluent treatment generally has within some organisations. For instance, although 64% of companies want their plants to deliver major innovations, 31% of production heads complain that they are not involved in new product development until all the decision making is done.
This is a major issue as product innovation and effluent treatment are closely linked; a new product formulation can cause a change in effluent characteristics and for 26% of our respondents, this leads to treatment problems.
In another example of organisations failing to consider the knock-on impact of their business decisions on wastewater treatment, 69% of companies studied are under pressure from senior management to boost plant throughput, yet one in five has no additional treatment capacity to cope with such an increase in production. In this situation, something has to give and if care isn’t taken, that could be compliance.
I believe that greater consideration needs to be given to the effect of production decisions, including changing shift patterns, the use of new cleaning chemicals or introducing new product formulations, on treatment plants.
At the moment, unexpected effluent treatment problems cause considerable disruption and can incur huge costs. But by considering how to respond to these problems and putting contingency plans in place, effluent treatment needn’t be a problem and businesses can be reassured that they will remain compliant. The good news is that the technology to achieve this is available.
The latest effluent treatment technologies
One technology that should be high on the list for consideration is Dissolved Air Flotation (DAF), which we see being used in many interesting ways.
DAF units are commonly used for the removal of fats, oils and greases, suspended solids and associated Biochemical Oxygen Demand (BOD), which would typically have poor settling characteristics.
DAF units create ‘white-water’ by dissolving air under pressure into recirculated water - as the pressure is released when the water is returned back into the DAF unit, micro-fine air bubbles are formed, which attach themselves onto the solids, and rise to the surface.
Here, the accumulating solids thicken and dewater before being removed by means of a mechanical scraper. The addition of lamella plates to a DAF allows a relatively high flow rate to be treated by a compact unit.
For instance, at one typical customer’s site, our 2.4m wide x 6m long unit was used to treat a peak flow rate of 144m3/h and DAF solutions are available whether the flow rate is 1m3 or 150 m3 per hour.
In building-block fashion, modular DAF units can be easily combined with other equipment to create tailored solutions, where ancillary mixed reaction tanks, containerised dosing and pumping equipment can be deployed with the DAF to provide additional treatment capacity when it is needed. This flexibility means DAFs can be used in a variety of creative ways to aid problem solving.
For example, producers of seasonal products can experience significant production spikes which create big waste treatment issues and serious cost implications.
To manage this, we are increasingly seeing manufacturers using temporary DAF equipment to add extra effluent treatment capacity during busy periods.
Over 30% of the companies involved in our study had experienced an emergency effluent treatment problem which put their compliance at risk and, again, DAFs are ideal in this scenario. They can be installed very quickly and easily and, if necessary, can be fully operational within just hours of arrival.
DAF technology is also an easy way to boost permanent treatment capacity, keeping companies compliant by managing effluent treatment as production increases.
Moving Bed Bio-Reactors, or MBBRs, are another technology that we have been focused on developing to support the market for the better management of effluent.
While it’s true that MBBR is not a new technology having been in successful operation in Scandinavia since the late 1980s, its use has yet to become established in the UK.
This surprises me as, in comparison with a popular technology like Submerged Aerated Filter systems, the MBBR process offers greater treatment capacity per unit volume and so, on a like for like basis is significantly less expensive.
We have been able to successfully apply MBBR technology to a number of temporary and permanent applications including BOD removal from municipal sewage, nitrification and the treatment of various industrial effluents ranging from whiskey distilleries to carrot juice.
In doing so we have learnt an awful lot about the technology and the high removal rates it can sustain. As a result, we are more convinced than ever that MBBR has a significant role to play in industrial waste water treatment.
MBBR technology has been extensively embraced by the rest of the world, and our successful UK trials have demonstrated that it can work equally well here, in a multitude of situations.