Trickling filters provide a reliable, efficient and cost-effective solution to almost any municipal or industrial wastewater treatment requirement - BOD removal, nitrification and denitrification. However, a trickling filter installation is only as good as the quality and reliability of each component part, particularly those which form the filter’s basic infrastructure such as the rotary distributor. A trickling filter is only as good as its rotary distributor. Without consistent and reliable wastewater distribution, a trickling filter will neither operate efficiently nor deliver the results you want.

Making the right choice of rotary distributor is as important as any other decision you make - for example, the type of media - when planning and buying wastewater treatment plant.

With the right rotary distributor in place, the trickling filter will deliver the level of operational effectiveness and service quality you need to maximise long-term return on your investment.

• Know the Market: Making to the right choice requires a thorough understanding of what’s available in the marketplace. In recent years, rotary distributor technology has evolved to offer more than the generic products that are still regarded by even the canniest wastewater management professionals as the industry standard.
• Know what you want - and how to get it!: As far as 2H Water Technologies is concerned, every conversation we have with a customer starts at the same point: their needs. We believe that no two customers and no two wastewater treatment challenges are the same. Every aspect of a truly successful trickling filter installation must be purpose-built to meet the client’s exact technical, operational and logistical specifications.

It is that philosophy which is evident in Equiflo and makes it stand out from the crowd. Equiflo is a new concept in intelligent, modular rotary distributor design designed and built to eliminate common problems; notably water damage and blockages, and provide the consistent, even wastewater distribution required for effective trickling filter performance.

The key difference is that, unlike most rotary distributors on the market, Equiflo is not a generic, off-the shelf product. Instead, every Equiflo is unique, designed and built from modular, precision-built components to the client’s exact technical and operational specifications.

• Built to fail: Many ‘standard’ rotary distributors have fundamental design faults that, regardless of the time and money you dedicate to design, management and maintenance, increase the likelihood of problems, breakdown and expense.
• What happens when there is a problem...? Wastewater treatment comes to a temporary stop while tricking filter operation is suspended to allow the rotary distributor to be dismounted, dismantled and repaired.
• Unplanned downtime costs and disrupts operations: Even a single incident has a negative impact on operational effectiveness, budget and, crucially, service quality. Because problems such as water damage and blockages are due to in-built design faults in the distributor - and therefore the trickling filter - the odds are that the same problems will occur time and time again, becoming increasingly more complex, time-consuming and costly to resolve.

Equiflo rotary distributors are innovative, practical, durable and reliable. Key benefits include:

• Easily handles all types of flows - municipal or industrial.
• Elegant, robust, modular design ensures long-term effective operation and reliability.
• Ensures consistent, even wastewater distribution.
• Motor and electrical parts mounted above feed water level ensures they are not constantly wetted.
• Easy maintenance, repair and cleaning.
• Fast, simple, cost-effective upgrade.
• Worn parts can be replaced quickly and simply without dismounting the rotary distributor.
• Excellent long-term ROI.
• And low operating costs over 25-year working life.

The most common causes of rotary distributor breakdown are water damage and blockages, both of which can be avoided by selecting a rotary distributor that is free from basic design faults.

Eliminate the cause of water damage: Despite lacking all logic, most rotary distributors have electrical components - motor and bearings - positioned far too close to the wetted area. No surprise then, that water damage is a frequent occurrence. The solution is simple. Choose a more ‘sensible’ and up-to-date design which, like Equiflo, has its motor and electrical parts mounted well above the water level thereby ensuring they remain problem-free.

We also recommend that you consider a direct-drive motorized version which does not need additional support from an air service or belt-drive system. Another feature offered by Equiflo, which we believe should be on your shopping list, is the ability to disengage and switch to hydraulic operation if there is an electrical
malfunction or failure.

Blockage-free distributor arms: ENEXIO 2H Water Technologies advise foregoing the standard tubular distributor arms, particularly those fitted with nozzles as they’re notoriously prone to blockage. We offer a choice of two, four or six ‘trough’ shaped distribution arms to Equiflo, each of which is formed in multiple sections for flexibility and easy maintenance.

Here’s a guide to the essential features and benefits you should expect from a rotary distributor. if your supplier’s offering does not meet these criteria, we recommend taking a closer look at the features and benefits of the Equiflo Rotary Distributor:

• Drive motor mounted on top of distributor: Motor is mounted well above the wetted area of the filter so avoids constant wetting.
• Drive motor is direct drive: No requirement for air service or belt drive system required.
• Drive motor automatic disengage: Disengage system for motor failure is a simple mechanical by-pass.
• Splash plate application: Creates a curtain effect to ensure all the media contributes to the process.
• Proof of curtain effect: Pan test as part of final installation set up.
• Adjustable base plate installation: Simplifies the civil requirements and accurate distributor levelling.
• Open trough arms: Not prone to blockage like tubular arms with nozzles.
• Manufactured in stainless steel: Ensures distributor life is minimum 25 years.
• Top mounted main bearing: Allows changing with just support from the distributor support column.
• Motor removing davit: The removable davit lifts motor and lowers to ground without a crane.

Flexible, modular design puts you in control: Have you ever agreed to cover the cost of adapting your premises to accommodate new plant? Or paid the price (in downtime, erratic productivity and maintenance time and costs) of installing equipment with intractable if mundane practical or logistical limitations which, when you made your buying decision, did not seem to be such a big deal.

Compromise costs - and it is generally the customer who foots the bill; a rule of thumb should be that if the rotary distributor (or any other equipment) cannot be adapted to suit the proposed location, then do not buy it.

The modular, flexible structure ensures you’re in charge of every aspect of Equiflo’s design and build. Equiflo can be customised to fit, and work effectively, in almost any location.

For example, Equiflo can be customised to be mounted off feed pipework flanges, concrete pillars or suspended from over-head beams and bridges. It can be adapted to operate with the water supply that suits your plant or installation: supplied from the bottom or top.

Take active control: The ‘ideal’ choice rotary distributor should allow you to plan for, and take active control, of vital, and potentially complex processes, such as handling different levels of wastewater composition and flow.

For example, the Equiflo Rotary Distributor can be adjusted to provide consistent distribution for applications with very high fluctuations in flow. It will automatically adjust distribution to meet temporary or seasonal variations. One early adopter, Thatcher’s, has had great success using Equiflo in a plant which, at different times in the year, pulps different varieties of fruit - from berries to apples - for use in the production of squashes and ciders.

Clean, maintain, repair without fuss or downtime: Another important factor to bear in mind when making your buying decision is whether essential tasks - repair, cleaning, maintenance or replacement - can be achieved without dismounting the rotary distributor or suspending trickling filter operation. In contrast to most products currently on offer, each Equiflo Rotary Distributor is individually crafted from modular, precision-engineered components which can be removed, cleaned, repaired or replaced without any impact on production.

Easy, cost-effective upgrades enhance ROI: General wear and tear is inevitable but, for many rotary distributors, even minor depreciation can signal the end of productive working life. Unlike Equiflo, which is built from modular components, there’s only one option and that’s finding the budget to pay for a replacement rotary distributor. Manufactured in robust stainless steel, the Equiflo Rotary Distributor is easy to clean, maintain and, most importantly, upgrade. When a part is worn, broken or just needs to be updated, it can be replaced.

Since Equiflo came onto the market in 2015, it has quickly become the distributor-of-choice for customers who recognise and value the rotary distributor’s unique capabilities.

Thatchers Cider, Somerset: When increased, demand prompted a 60% increase in production, Thatcher’s Cider asked ENEXIO 2H Water Technologies to upgrade its effluent treatment plant in Sandford, Somerset. A purpose-built solution which includes BIOdek structured plastic media and a customised Equiflo Rotary Distributor copes easily with a substantial BOD/COD load, which varies significantly, and keeps the facility within consent. In its first industrial installation, Equiflo has proven to be practical, durable and effective.

South West Water, Woolsery WwTW: South West Water became Equiflo’s first municipal user when it installed the new Rotary Distributor at its Woolsery WwTW. Equiflo was part of a solution commissioned by Interserve Construction, primary contractors charged with building a nitrifying filter specified by consultants, Pell Frischmann, at the Woolsery WWT plant. Following consultation with Interserve Construction and SWW, ENEXIO 2H Water Technologies designed, manufactured and installed BIOdek KFP619 cross flow plastic media and a customised Equiflo variable speed rotary distributor.

ENEXIO 2H Water Technologies is the UK’s leading manufacturer of plastic media for water and wastewater management plant. ENEXIO 2H Water Technologies designs, manufactures and supplies products and equipment that deliver measurable results in a wide range of applications including utilities; water and wastewater treatment, industrial effluent treatment and general industrial water cooling. The company’s industry-leading product ranges include BIOdek, PLASdek, TUBEdek and SANIPACKING. 2H Water Technologies works closely with specifiers, architects and civil engineers in the design and installation of a wide range of industrial projects.

During its 30 years in business, 2H has built an outstanding reputation for quality products and services. 2H comprises the former Environmental Control Division of Munters, Ranik and 2H Aqua operations.

By 2050, total water demand in England and Wales is expected to increase by 35%. Per predictions by the Office for National Statistics, the UK population will reach 71.4 million by 2030, and 78.4 million by 2050. Climate change projections suggest summer temperatures will increase while rainfall will decrease leading to an 80% reduction in gatherable rainfall. As climate change, groundwater depletion and population growth heap additional pressure on finite freshwater resources, treating wastewater to potable standards is gaining recognition as a sustainable method of supplementing water supplies.

Industry commentators often use the phrase ‘toilet to tap’ which, while not entirely accurate, encapsulates the challenge of converting contaminant-laden, ‘tough to treat’ wastewater into potable water that meets the strictest regulatory standards.

The industry-leading range of TUBEdek^TM lamella separation tubular settlers from Enexio 2H Water Technologies play a vital part in the potable water treatment by removing solids from the raw water intake during the settlement process. At this point, there will be several thousand milligrams of sludge, sand and silts per litre of surface water. In addition, the chemical precipitation and flocculation processes produce significant amounts of solids.

The most economical method of removing this type of pollution is parallel plate sedimentation as used in TUBEdek^TM.

TUBEdek^TM lamella settlement fills utilise a chevron plate sedimentation process which is a more effective method of separating solids from liquids. The uniform configuration and inclined angle of the tubes encourages laminar flow for efficient solids separation whilst the ‘v’ shape encourages a more even discharge of solids to the settlement zone below the TUBEdek^TM modules.

The tubes are designed to adapt easily to any process design requirement by varying the inclination, length of tubes and module sizes.

Because TUBEdek^TM uses a parallel plate sedimentation process, multiple plates can be housed in a single, cost-effective tank and not, as with many other products, in lots of large and expensive tanks.

The tongue and groove design is another unique aspect of TUBEdek^TM. The design not only simplifies assembly - a significant bonus for large schemes where TUBEdek^TM modules can be built close or even adjacent to the main site - but also ensures exceptional mechanical strength.

The TUBEdek^TM range includes certified products for all potable water applications from Highland whisky to tap water.

• Hydraulic parameters improve efficiency (Reynolds number).
• Equidistant channels for full sedimentation.
• Special support systems avoid impact on the process.
• Up to 15 sedimentation planes above one m² of base.
• Manufactured in polypropylene which is suitable for all potable water applications.

Surface water can be polluted by a wide range of contaminants including agricultural, industrial or municipal discharges of nitrogen (ammonia or nitrate). Biological processes - such as nitrification and denitrification - are effective in removing this type of pollutant. However, nitrification and denitrification need carriers with surfaces to establish and maintain the biomass. Enexio 2H Water Technologies supplies a large variety of such carrier materials including the BCN-range for moving bed or BIOdek KFP319 for structured media reactors.

TUBEdek^TM packing is designed to achieve an intense mixture of water and air to bring the oxygen content up to saturation point and enable oxidization of the dissolved iron. The iron precipitates either in or below the packing at which point it can be removed by filtration or sedimentation.

Every TUBEdek^TM installation is a customised solution, purpose-built to deliver the customer’s objectives of improving processing efficiency while treating heavier loads and higher effluent flows - all while meeting tighter discharge consents.

South East Water is one such customer and was the first UK municipal water company to go live with Enexio 2H Water Technologies’ Drinking Water Inspectorate Reg 31 approved TUBEdek^TM FS41.50PP product at its Keleher WTW in Bray, Berkshire. Almost immediately, the Keleher plant recorded a significant increase in productivity and operational reliability.

South East Water provides drinking water to over 2.1 million customers in an area which encompasses Kent, Sussex, Surrey, Hampshire and Berkshire.

The region has relatively low rainfall compared to the rest of the UK. It also has a dense and fast growing population with a higher per capita rate of water consumption than other comparable areas of the UK. It is no surprise that region has been classed as ‘seriously water stressed’.

South East Water is continually developing new water resources. In its latest Water Resources Management Plan (WRMP), issued in 2015, the company committed to investing £400 million in developing new water sources.

One of the largest projects in South East Water’s five-year programme of work was the extension to Keleher WTW. Located in Bray, Berkshire, the works currently supplies drinking water to 2.1 million customers in Berkshire, Surrey, Hampshire, Sussex and Kent, and treats 30 million litres of wastewater per annum.

Brian Steventon, Project Manager at South East Water, said:

“TUBEdek^TM met all our objectives, most notably in removing the bottleneck that restricted output in the previous horizontal lamella clarification system. Within months, we were seeing average flows between 30Mld and the maximum 45Mld which was a significant improvement on the 22Mld we achieved with our previous system.

“In addition, the upgrade project provided an opportunity to improve process control and increase the throughput of the clarifiers from 25ML/d to 40ML/d.

“South East Water considered several alternatives to TUBEdek^TM. We looked at replacing the existing horizontal lamella clarification system but rejected that option as it wouldn’t provide the required improvements in production capacity. We also investigated a stainless-steel alternative which seemed effective but was very expensive.

“We chose TUBEdek^TM because it was the best match for our requirements; price, performance and DWI Reg 31 accreditation. We were confident that TUBEdek^TM could deliver the required improvements in performance - notably in hazen velocity - and we had the reassurance that comes from DWI accreditation.”