Water Treatment

The evolution of wastewater treatment

Established in 1973, UK-based Airedale Chemical specializes in the manufacture and distribution of commodity chemicals, polymers, surfactants, phosphates and phosphonates to an extensive range of market sectors across the UK and Europe. Daniel Marr, the company’s commercial director, looks at the ever-changing world of wastewater treatment processes and the essential role of the chemicals it uses.


rom the earliest use of coagulation implemented by the Ancient Greeks, to the UK Water Act1 of 2014, humankind has been pursuing the best way to process water that can be cleaned and re-used. But as industry grew, so did regulations to protect the water supply from contamination from waste and increased industrial activity. New techniques including aeration, flocculation and active carbon adsorption were developed and the modern water treatment process we know now began to emerge.

Keeping up with technology

However, wastewater companies are still constantly embracing new technologies to optimize the water cleansing outcome. For instance, novel polymeric membranes are now employed to neutralize, decolorize and deodorize water streams, thereby enabling successful use of closed-loop systems that minimize freshwater draw.

Foam control has also seen major breakthroughs. Manufacturers such as BRB International BV now offer cutting-edge silicone antifoam technologies developed for use in tandem with electronic foam- sensing probes to best control dosing rates that deliver maximum cost efficiency.

Fluctuating demand

Demand for water has also seen many changes but has generally stuck to a rising trajectory. However, the use of water differs quite significantly between industry


Energy, chemical, coatings and food processing companies are amongst the largest industrial consumers of antifoam. (Photo: Airedale Chemical)

and urban conurbations, with sectors such as agriculture and manufacturing consuming ever- increasing volumes of water that are significantly greater than the usage seen in towns and cities. The increasing demand for clean water is also commensurate with society’s improved norms of personal hygiene and the cleanliness of clothes. Consumers are now demanding more advanced surface cleaning and protection products. A move away from solvent-based consumer products to water- based alternatives that are more environmentally friendly is contributing to this trend, thereby generating increased demand for wash-water processing that often

generates foam. Energy, chemical, coatings and food processing companies are amongst the largest industrial consumers of antifoam and, therefore, strong industrial activity levels, coupled with a growing economy influenced by confident consumers, can drive a strong surge in demand Industries such as textiles processing and bioethanol production have had a huge influence on both the demand for antifoams and the innovations in their development. It therefore follows that antifoams have become a vital and major element in maintaining the efficient process of treating and cleaning foam-susceptible wastewater streams. A carefully

selected antifoam will ensure quick and effective foam knock- down without impacting the effectiveness of other process aids in the system, such as flocculants and coagulants. Elimination of foam leads to significant improvements in plant throughput, ensuring maximum utility of vessels, pumps and valves, which in turn leads to a cleaner, safer workplace.

Life before antifoams

Prior to the wide commercialization of antifoam, which occurred almost 60 years ago, unsophisticated physical/mechanical methods of foam removal were employed. However, the ubiquitous demand for improved plant speed and efficiency created a need for more purposeful techniques. What

Author: Daniel Marr is the commercial director of Airedale Chemical where he oversees the company’s technical, sales and communications functions. He gained 15 years of experience in marketing after graduating from Leeds Beckett University and has been with Airedale Chemical since 2011.

Antifoam manufacture in chemical reactors at Airedale Chemical. (Photo: Airedale Chemical)

followed was the development of ever more sophisticated antifoams, optimized to work reliably at the lowest dosage rates with zero impact on the process or quality of the final effluent.

Silicone vs non-silicone

The increasing demand for clean water is also commensurate with society’s improved norms of personal hygiene and the cleanliness of clothes. Consumers are now demanding more advanced surface cleaning and protection products.

Both silicone and non-silicone antifoams are widely used in water treatment. However, silicone antifoams have one of the lowest surface tensions, meaning they are excellent at wetting and rinsing the bubble-wall of the foam, thereby pricking the bubble instantly. This performance speed is partnered with excellent longevity, even at the lowest dosage rates, meaning these products are very economical to use. Unlike many non-silicone products, these

silicone counterparts function effectively across the broadest temperature range, in both water-containing and water-free processes. They are easy to use in bright-white liquids, being fully dispersible in water, odourless and tasteless, thus eliminating any chance of final product taint.

Choosing the right antifoam for the job One of the great advantages of silicone based defoamers is their broad versatility. Their unique physio-chemical foam-destroying mechanism means they are just as likely to be found functioning as an antifoam, supressing actual formation of foam before it is created, as they are a defoamer, destroying foam already in-situ.

Despite this efficiency of silicone antifoams, there are some applications where non-silicone remains the chemistry of choice. In starch processing, for instance, they are the ideal solution, but it is recommended that the cost efficiencies of a silicone solution are explored in the first instance. Airedale Chemical’s antifoam supplier, BRB International BV, has been utilizing its laboratory to assess foam-susceptible liquors and prescribe an optimized foam control solution, amongst other innovations. A recent distribution agreement between Airedale Chemical and BRB International means Airedale is able to ensure the supply of these most up-to-date solutions for this ever-changing and

absolutely essential industry. The water treatment industry has a guaranteed future but the methods and chemicals it uses have been evolving for thousands of years and there is no reason to believe that will change anytime soon.

Reference: 1. ukpga/2014/21/pdfs/ukpga_20140021_ en.pdf

Further information Daniel Marr

Commercial Director Airedale Chemical Ph: +44 (0)1535 637876 E: enquiries@ W: www.airedalechemical. com.

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Water Treatment

Autumn 2020

Autumn 2020


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