Chemical Industry

The history of brine extraction and its role in producing water treatment chemicals

Brine extraction in Britain, particularly in Cheshire, has a long industrial heritage that dates back to at least the Roman period and expanded markedly during the 18th and 19th centuries with industrialisation. Salt beds laid down by ancient seas underlie large parts of Cheshire; their accessibility and the demand for salt and related chemicals drove the development of brine pumping and refining technologies.

Key historical milestones

• Early salt production: Surface salt pans and natural brine springs were exploited in Roman and medieval times. By the 1600s–1700s, commercial saltworks developed around natural springs and coastal evaporation sites.

• Industrial Revolution expansion: From the late 18th century, Cheshire became a major centre for salt production. Advancements in steam power and deep-well pumping allowed extraction of large volumes of brine from subterranean rock salt seams.

• Chemical industry birth: In the 19th century, the Solvay process, Leblanc process and later improvements transformed salt (sodium chloride) and brine derivatives into a wider range of chemical products. Chlor-alkali chemistry—electrolysis of brine to produce chlorine and caustic soda (sodium hydroxide)—became a foundation for many industrial chemical chains, including the manufacture of water treatment chemicals.

• 20th century modernisation: Electrolytic cell technology matured (mercury-cell, diaphragm-cell and membrane-cell processes), enabling higher-purity outputs and larger-scale production. Companies consolidated, and integrated chemical complexes developed adjacent to brine extraction sites to reduce transport costs and secure feedstock supply.

• Post-war diversification and environmental pressure: The mid- to late 20th century saw diversification into a wider suite of chlorine-derived and sodium-derived compounds used in textiles, paper, plastics and water treatment. Increasing environmental regulation prompted shifts away from mercury cells and encouraged cleaner technologies.

• Recent decades: Ownership changes, privatisation, and globalisation concentrated production in fewer, more efficient sites. Major operators in Cheshire built extensive brine extraction, purification and electrochemical processing plants that supply both commodity chemicals and specialist water-treatment products.

How brine becomes water treatment chemicals — the processing chain

1. Brine extraction

   • Solution mining / pumped brine: Freshwater is injected into salt beds to dissolve rock salt, creating a brine that is pumped to the surface. Alternatively, natural groundwater-saturated brine may be pumped from wells.

   • Mechanical pumping from saturated seams: In some sites, mechanical pumps bring naturally occurring brine to surface.

   • Brine quality control: Extracted brine contains dissolved salts (primarily sodium chloride) and impurities (gypsum, magnesium, organic matter). Initial on-site screening and sampling determine treatment needs.

2. Brine purification

   • Filtration and settling: Large particulates and suspended solids are removed by settling tanks and filtration.

   • Precipitation and ion exchange: Calcium and magnesium hardness are removed where necessary (e.g., via lime softening or chemical precipitation) to avoid fouling downstream electrolytic cells.

   • Evaporation/crystallisation (where applicable): For salt production, brine may be concentrated and evaporated to crystallise common salt, separating it from mother liquor for further processing.

3. Electrolysis (chlor-alkali process)

   • Cell types: Brine is fed to electrochemical cells—modern plants use membrane cells to split sodium chloride solution into chlorine gas at the anode and hydroxide ions at the cathode, producing hydrogen gas as a by-product and sodium hydroxide solution (caustic soda).

   • Product handling: Chlorine is captured, dried and compressed or liquified for use in downstream synthesis. Caustic soda is concentrated, stored, and transported as a liquid or solid (via evaporation to flakes or pellets).

   • Energy and environmental considerations: Electrolysis is energy-intensive. Technology upgrades focus on energy efficiency, reduced emissions and safer handling (replacing older mercury or diaphragm cells with membrane cells).

4. Further chemical synthesis and conversion

   • Chlorine derivatives: Chlorine is a feedstock for a wide range of chemicals—chlorinated solvents (historically), PVC (via ethylene dichloride and vinyl chloride monomer), and bleaching agents. For water treatment specifically, chlorine is used directly as a disinfectant (gaseous chlorine, sodium hypochlorite from chlorination of caustic solution, or bleaching powder).

   • Sodium hypochlorite and calcium hypochlorite: Chlorine can be reacted with caustic soda to form sodium hypochlorite, a common on-site water disinfectant. Calcium hypochlorite may be manufactured by further reaction and solidification routes.

ABS vs PVC pipework

For swimming pool pipework and chemical water treatment systems, PVC (polyvinyl chloride) is generally the better choice over ABS (acrylonitrile butadiene styrene). Key reasons and practical considerations:

Performance and compatibility

• Chemical resistance: PVC has excellent resistance to common pool chemicals (chlorine, pH adjustments, algaecides) and many treatment additives. ABS is resistant to some chemicals but is more susceptible to degradation from prolonged contact with certain solvents and aggressive oxidisers used in some treatment regimes.

• Temperature resistance: PVC (especially uPVC and CPVC variants where used) handles the typical temperature range of pool systems well. ABS can become brittle in colder conditions and may soften with sustained high temperatures; neither is ideal for very hot water but PVC is more commonly specified for pool plant rooms.

• Mechanical properties: PVC offers good stiffness and dimensional stability for pressurised pool circuits, and is widely available in pressure-rated DN sizes and fittings.

Installation and standards

• Availability: PVC pressure pipe and fittings are widely available in swimming pool industry sizes and pressure ratings; many pool components (valves, unions, skimmers) are designed for PVC connections.

• Joining methods: Solvent-weld (glue) PVC joints are standard and form reliable, watertight connections when done correctly. ABS can also be solvent-welded but uses different solvent cements which are less commonly stocked for pool installers.

• Codes and norms: Pool builders, plant designers and many local regulations commonly specify PVC for pool circulation and chemical dosing lines. Using industry-standard materials simplifies approvals and maintenance.

Durability and maintenance

• Longevity: PVC is proven in pool installations for decades with low maintenance. It resists scaling and is easy to inspect for leaks or damage.

• Repairability: PVC fittings and repair parts are widely available, making in-service repairs straightforward. ABS parts are less common in the pool sector.

Specific use-cases and exceptions

• Underground drainage: ABS is often used for non-pressurised drainage systems in some countries; for pool balance tanks and overflow drains, purpose-rated drainpipes (often PVC or polyethylene depending on local practice) are used.

• Hot water systems: For very high-temperature applications (e.g., spa heaters or plant-room hot-water loops) CPVC or other heat-rated materials may be preferable to standard PVC. ABS is not recommended for hot pressurised lines.

• Chemical dosing lines: For small-bore dosing lines carrying concentrated acids or alkalis, specialist materials (PTFE, PVDF, HDPE) or chemically compatible PVC/CPVC may be required rather than standard PVC/ABS.

Summary recommendation

• Use pressure-rated PVC (uPVC or CPVC where higher temperature resistance is needed) for swimming pool circulation, filtration, and most chemical treatment piping.

• Reserve ABS for non-pressurised drainage where specified by local practice, but generally avoid ABS in pool circulation and chemical dosing systems.

• For concentrated chemicals, hot lines, or unusual chemistries, consult material-compatibility charts and a pool plant engineer to select specialist materials (PVDF, PTFE, HDPE or CPVC) as required.

Pool Building

It all began back in 2007 when a pool contractor approached me and invited me to join their team, working on the installation of pools, and from that moment, my career in this industry truly took shape. Since 2007, I have had the privilege of installing over 400 swimming pools throughout the UK and Ireland, gaining invaluable experience along the way.

My formal training began in Italy with Myrtha Pools, a company renowned worldwide as the leading installer of Olympic and Competition pools. To further expand my expertise, I then completed additional training with Astral Pools in Spain, another global leader in Olympic-standard pool installations. The industry quickly captivated me, the variety and challenges of the work meant that no two days were ever the same. One day I might be involved in shuttering and groundwork, the next installing bespoke pool panel systems, or honing my fine carpentry skills to create a luxury sauna.

Before long, I decided to take the leap and establish my own business. My focus shifted toward innovative design improvements and solving complex problems on site. I designed my own unique pool panel system and embarked on a journey to create bespoke stainless steel one-piece pools. This dedication and innovative approach opened doors to working with many prestigious clients across the UK and Ireland, allowing me to continue growing and refining my craft in this dynamic industry.

The next chapter of my journey is using my skill set to Consult and offer a standard form of Tendering and procurement to the pool industry. This will offer a level of transparency and offer full project formal specification that will ensure the client gets the pool and associated equipment that they want.

It all Goes Swimmily

When considering building a swimming pool, you need to carefully evaluate several important factors to ensure the final result meets both functional and aesthetic requirements. These include the pool design and pipework layout, turnover and circulation rates, as well as the anticipated bather volume to determine appropriate capacity. Water temperature control, incorporation of special features, and the use of a heat-retaining pool cover are also crucial considerations. Safety measures, floor design, and the inclusion of a secondary channel for wastewater management should not be overlooked. Additional elements such as washdown systems, floor finish and slip resistance, wall and interior finishes, ceiling design, glazing, and ducting all play vital roles in the overall environment. Environmental management systems, mechanical and electrical installations, DMX lighting with sequencing options, and the accommodation of both wet and dry traffic areas need to be planned carefully. Facilities like changing rooms, washrooms, plant rooms, and systems for water treatment, filtration, chemical dosing, and safe storage of chemicals contribute to operational efficiency. Effective water sterilisation methods, conveniently placed feature control panels and switches, as well as comprehensive pool control panels ensure smooth pool functionality. Considerations for backwashing, routine maintenance, reliable chemical supply, sufficient access points, and adherence to health and safety regulations are equally essential to achieve a successful and sustainable swimming pool project.

Sauna v’s Steam Room

Health Advantages of a Sauna:

• Improved Cardiovascular Health: Regular sauna use can help enhance circulation and lower blood pressure.

• Muscle Relaxation and Recovery: The dry heat soothes muscle tension and aids recovery after physical activity.

• Detoxification: Sweating helps expel toxins from the body.

• Stress Reduction: The calming heat promotes relaxation and reduces cortisol levels.

• Skin Health: The heat opens pores, improving skin cleansing and complexion.

• Enhanced Immune Function: Frequent use may help boost the immune system by increasing white blood cell production.

Health Advantages of a Steam Room:

• Respiratory Relief: The moist heat helps clear congestion, easing breathing issues such as asthma, bronchitis, and sinusitis.

• Skin Hydration: The humidity moisturises the skin, improving elasticity and preventing dryness.

• Muscle Relaxation and Pain Relief: Steam can loosen stiff muscles and joints and alleviate pain from conditions like arthritis.

• Improved Circulation: Promotes blood flow similarly to a sauna but with the benefit of added moisture.

• Stress Reduction: The warmth and humidity help relax the body and mind.

• Enhanced Detoxification: Steam induces sweating, aiding in the removal of impurities.

Why Install Both a Sauna and Steam Room:

Installing both a sauna and a steam room provides a comprehensive wellness experience, catering to diverse health needs and personal preferences. A sauna’s dry heat suits those seeking intense sweating and cardiovascular benefits, while the steam room’s moist heat is ideal for respiratory health and skin hydration. Together, they offer a balanced approach to relaxation, detoxification, and therapeutic effects, enhancing the overall value and appeal of your wellness space for both private and commercial use.

Ice Therapy and Cold Plunge

Ice therapy, cold plunge pools, and wild swimming offer numerous health advantages that are deeply rooted in the benefits of exposure to cold water. One of the primary benefits is the significant reduction of inflammation throughout the body. When immersed in cold water, blood vessels constrict, which helps to decrease swelling and alleviate muscle soreness, making these practices particularly effective for recovery after strenuous physical exercise.

Additionally, cold immersion stimulates the autonomic nervous system, which promotes improved blood circulation. Upon exiting the cold environment, blood vessels then dilate, flooding the areas with fresh, oxygenated blood. This process aids tissue repair and contributes to enhanced overall cardiovascular health.

Cold exposure also triggers the release of endorphins and adrenaline, natural chemicals that can uplift mood and help reduce stress levels. Regular cold water swimmers often report a decrease in symptoms related to anxiety and depression as a result. Furthermore, wild swimming and cold plunges encourage the development of mental resilience and increase tolerance to physical and psychological stress, fostering a greater sense of well-being and mental clarity.

From an immune perspective, consistent cold exposure can lead to an increase in white blood cell counts, boosting the body's ability to resist illnesses and infections. Lastly, cold therapy has been found to improve sleep quality by encouraging relaxation and reducing the hyperactivity of the nervous system in the period leading up to bedtime.

In summary, ice therapy, cold plunges, and wild swimming provide comprehensive support for physical recovery, cardiovascular health, mental well-being, and immune system function, all through the unique and powerful benefits that come with exposure to cold water.