Ashley Shepherd, UK sales manager at pumping specialist, Watson-Marlow Bredel, talks about the importance of accurate effluent treatment for the food manufacturing sector in the context of the Water Framework Directive.
The process of wastewater treatment is set to change forever with the introduction of the Water Framework Directive, which aims to rationalise and update existing water legislation, as well as improve standards of protection for the water environment. While the food manufacturing industry currently operates under fairly stringent restrictions, they are set to become much stricter.
The management of wastewater is a complex and expensive process. Manufacturers have the choice of treating their own effluent, or paying trade effluent prices. The latter option has become so costly that many companies are now setting up their own private treatment centres. This has the added benefit of allowing appropriately treated water to be recycled back into the manufacturing process; an initiative that saves both money and water.
With stricter control over effluent becoming more important, accuracy of chemical dosing is vital. Many existing pumping systems may not be able to perform to the levels that will be required by the Water Framework Directive, particularly for those wishing to recycle their own water. Water industry representative, Water UK, has recently revised the guidelines on treating effluent, making them tougher, and reinforcing the importance of ensuring that polluted water stays out of the public sewerage system.
In the words of Steve Ntifo, science and environment adviser at Water UK: “Trade effluent consents are among the UK’s most important environment protection measures. The revised guidelines provide a clearer process and will make it easier for businesses and sewerage companies to ensure compliance with legislation.”
“The guidelines also carry a strong environmental message about the composition of products and their overall impact on the environment. They should give businesses an extra incentive to improve their operations and bottom line by cutting out substances that need additional treatment and so attract higher discharge consent charges.”
The water companies are also enforcing the treatment of effluent in an increasingly rigorous manner. Recently, a Southall-based ethnic food company has been fined nearly £50,000 for illegally discharging oils, fats and grease into the sewerage system. Tests on their effluent showed it was three times over the allowed limit for these substances. Though currently relatively rare, these fines are likely to become more common, and with such substantial charges, it is not in any business’s interests to risk the consequences of releasing inaccurately treated wastewater.
Water companies are being encouraged to become more proactive in terms of prosecuting, in line with the whole ‘polluter pays’ principle, which will be affirmed by the Water Framework Directive. The message is quite clear: effectively treat your effluent or face the financial consequences. Being held up for pollution charges is likely to have a detrimental effect for a company in terms of reputation among customers and stakeholders, particularly in consideration of the UK’s current heightened environmental awareness.
Paying closer attention to treating effluent does not have to include massive system upheaval. Finding the right technology allows for a simple retrofit to meet stricter dosing requirements. Negating the need for a new integrated system, peristaltic pumps can be used as ‘add ons’, offering a combination of dosing accuracy, reliability and ease of use.
Typically peristaltic pumps are used in sampling, metering, dispensing and transfer applications, and do not demand complex commissioning programs, additional check valves or hardware. Pump maintenance involves a simple tube changeover, which takes just a few minutes and can be carried out by unskilled operatives. This incredible low maintenance requirement enables a very low whole life pump cost, making peristaltic pumps far more economical than other positive displacement pump types.
Stand-alone pumps are self-priming and can be mounted externally at ground level or in a remote housing. Control can be manual or by analogue or digital signals from other instrumentation. The development of Profibus enabled pumps for release later this year will help environmental users too.
Rather than simply replacing an existing pump, peristaltics can also be used to substitute other, less flexible methods of chemical dosing. An example of this is a recent Watson-Marlow Bredel customer who previously treated effluent through dosing tablets. With the level of accuracy required today, this technique simply was not sophisticated enough to offer the required treatment. By installing one of our peristaltic pumps, the client, a food manufacturer, was able to fine-tune their treatment needs, while avoiding the use of labour intensive equipment.
Improving the performance of a wastewater treatment plant makes economical sense in terms of reducing operating costs, as well as more effective regulatory compliance. Accurate dosing avoids the need for corrective measures and ensures no excess energy is consumed.
If the Water Framework Directive is to meet its ultimate goal – that all inland and coastal waters reach ‘good’ status by 2015 – a huge revision of current wastewater regulations is necessary. The sooner manufacturing companies accept full responsibility for the treatment of their effluent, the sooner pollution problems will improve, and the need for water companies and regulators to enforce fines will be reduced.
