Axium Process has a range of stainless steel Manways for atmospheric and medium-pressure liquid, powder and grain applications in the food and pharmaceutical industries.

Axium Process Ltd is a new supplier of hygienic stainless steel components to the chemical, pharmaceutical, food, cosmetics and toiletries industries. The Manways, manufactured from 316 stainless steel, are available in rectangular, oval and circular form, with apertures ranging in size from 100mm to 1200mm. Hinged, multi-clamp and swivel-lever-arm designs are available, with domed lids and a glueless seal to minimise any potential bacterial contamination.

Material options available include 304 stainless steel and a variety of alloys, including Hastelloy and SMO254.

Full material certification to BS EN 10204 3.1.B is available for the glueless seal, domed lid options.

All manways are supplied with mirror polished lids and skirts finished to customer specification.

EPDM seals are standard on all manways, allowing operating temperatures between -25C and +150C.

A range of alternative seal material is available, which includes silicone, Viton and nitrile rubber.

Providing access to tanks, storage vessels and ducting systems, Axium Process hygienic manways are complemented by a range of ancillary items featuring level gauges, sight glasses and sprayballs.

The company also offers a comprehensive range of hygienic stainless steel components and pipe fittings which can be fabricated to customer specification by Axium Process coded welders (ASME IX).

Prep-Tec Systems recently supplyied 3 shop built and 2 site built stainless steel water tanks for Pulrose Power Station in the Isle Of Man: site tanks were constructed using a unique jacking system.

Prep-Tec Systems, a Bury, Lancashire based company have recently been involved in supplying 3 shop built and 2 site built water tanks for Pulrose Power Station in Douglas, Isle Of Man. The contract was part of a multi million pound development to transfer the existing oil fired power station to natural gas. The gas will be supplied direct from the Irish Sea.

The order to Prep-Tec Systems was awarded direct from the Isle of Man government who purposely formed a company PGT Ltd (Pulrose Gas Turbines) to oversee the development.

The tanks range from a 15 cubic metre horizontal cylindrical main cooling water system head tank, a 5 cubic metre cylindrical raw water break tank, and a 3 cubic metre vertical closed loop cooling water system head tank.

Each of the tanks was supplied in carbon steel with 15-year life paint finish to the internal and external surfaces.

The site built de-mineralised water tanks, each 225 cubic metre and 11.5 metres high, were manufactured in 316 quality stainless steel and erected one metre apart from each other.

The North tank was built with a spiral access stairway and the South tank with a hooped access ladder.

A bridge was fitted between each tank to join them together.

The components were shop formed and shipped to the Isle of Man on 3 articulated 12 metre trailers.

Due to the limited access the tanks were built using a unique jacking system where each of the top sections were erected and fully welded complete with lids, handrails etc and jacked up to allow the next course to be positioned under.

The tanks were progressively jacked up this way until all the sections were attached.

The staircase and ladders were also progressively attached this way.

The benefit of this method of construction is that all the work, welding etc can be completed at ground level, which eliminates the need for expensive crane hire and scaffolding.

Also the inside of the tanks are always closed off to the elements and the outside can be easily covered with a simple tent arrangement to allow welding to progress in any weather conditions.

Poeton Industries has been awarded a contract to apply Apticote 100 hard chromium plating to high-performance damper tubes for the suspension of the Mitsubishi Ralliart World Rally Championship cars.

The hard chromium application is described as an "extremely delicate job" by James Glover of SPA Design, the company that manufactures the damper tubes and other components for Ralliart. "It really is the most difficult surface treatment job we've been involved with" James commented: "and Poeton, with its combination of coating and motorsport experience, is the only company we've found that can meet the high standard we require". He adds that the damper tubes also have to be handled very carefully to minimise surface scuffing and avoid any contact with objects that might damage them.

Explaining the difficulties, he says: "The specification from Ralliart called for a hard wearing, low-friction coating for the damper tubes, which have very thin walls that need to be hard chrome coated inside and out to extremely tight bore tolerances.

The outside diameter also comes into contact with a fragile seal so the surface has to be free of any defects that might damage them".

The Poeton Apticote 100 hard chromium coating is one of a dozen processes that the damper tubes go through before they are delivered to Ralliart at a cost that runs into four figures for each one! Commenting for Poeton Motorsport Division, Neill Ricketts says: "We were delighted to accept the challenge from SPA Design, and happy that we could provide both the quality and the overnight service they needed.

It is also another example of how Apticote is helping motorsport companies win in the most demanding of environments".

The new Poeton coating technology centre boasts an array of wear and friction test equipment, and three environmental corrosion chambers, allowing Poeton to solve customer coating problems.

Poeton Industries Limited, a world leader in surface coating technology, has completed a 120,000 sterling investment in its Gloucester Technology Centre, creating a focal point of surface coating excellence within the Poeton Group, which also has production facilities in Cardiff, Southampton and the USA. The Centre was officially opened on Friday 15th January by Dr Keith Dennis, President of the Institute of Metal Finishing. Other VIP guests included John Kirkpatrick of the Motorsport Industry Association and Professor Frank Walsh, Professor in Electro-Chemical Engineering at the University of Bath.

Among the analytical and test equipment now in place are PC-driven microscopes capable of resolving surfaces and micro-sections down to sub-micron levels, with attachments that allow entry into bores only 2mm in diameter.

This investigative capability is supported by state-of-the-art chemical analysis, including Atomic Absorption.

Group R and D Director Keith Stevens says this level of sophistication underpins the Poeton position as one of the leading European surface engineering companies.

He also emphasises that much of the work carried out at the centre is of direct benefit to customers, explaining that his team has already been able to fast-track the successful resolution of problems such as in-service component failure by providing analysis that has saved customers from potentially expensive litigation.

The technology allows Poeton to solve customer coating problems, often via direct electronic transfer of images and reports.

Importantly, the new centre boasts an array of wear and friction test equipment, and three environmental corrosion chambers, allowing Poeton to pioneer ground-breaking developments in such diverse applications as F1 engines, plastic moulding and stylish beach wear.

Axium Process have strengthened their position in the manufacture of high purity stainless steel fittings for the process industry with the introduction of an Orbimatic Orbital Welding System.

Axium Process are now in a position to offer custom fittings of systems from 0.5 inch to 6 inch outside diameter using this system, the procedure can then be stored in the machines internal memory using a smart media card, which allows jobs to be very quickly re-produced at a later date. They can also use a range of other automated equipment to produce components up to 300mm in diameter. The Orbimatic system can produce true data log files, which will include exact deviations for each welded joint on the fitting, giving the customer confidence in the quality of the product supplied.

Managing Director, Dave Houldsworth, sums up the Axium Process company philosophy: "We provide a rapid, reliable and highly qualified supply and manufacturing service, focussed on the hygienic process industries.

Our aim is to exceed customers' expectations in terms of quality, delivery and service".

The introduction of the Orbimatic system helps Axium Process continue this with this philosophy and further increase the quality of the finished component.

The Metrohm 824 Easy Sample Changer is one that every Titration or Karl Fischer Plant Laboratory can afford, and is simple and easy to operate.

The Metrohm 824 Easy Sample Changer: one that every Titration or Karl Fischer Plant Laboratory can afford. This new instrument from Metrohm is extremely easy to operate thanks to a simple key-pad layout linked to pre-programmed methods. The 824 is available in two versions.

The Macro version for Titration where large volumes, up to 250 ml, are involved: here 12 samples are processed sequentially.

Plus the Micro version, which will handle 24 samples of up to 75ml.

This version can also be converted into a Karl Fischer sample changer by means of the accessory kit 6.5610.020 KFT.

Both versions are supplied with comprehensive accessories, which include a sample rack, glass or polypropylene beakers, stirrer and titration head, plus all cables to connect the sample changer to the Metrohm Titrando or Titrino ranges of Titrators and Karl Fischer moisture analysis systems.

All laboratories can now take advantage of the Metrohm Sample Changer to achieve: easy automation at affordable prices; Save money when processing large numbers of samples; Enhance the reproducibility of their manual techniques; Contact with toxic chemicals is reduced to a minimum; Operational personnel need no special knowledge; Operational personnel are freed to do other work; The laboratory can operate 7 days per week, 24hrs /day.

With a 100-year history, customers depend on Johnson Screens to create effective and cost-conscious solutions to problems across a range of industries, including water intake, treatment and monitoring.

With its 100-year history, customers depend on Johnson Screens to create effective and cost-conscious solutions for problems across a range of industries, including architectural, food processing, general industrial, petrochemical processing, and water intake, treatment and monitoring. The company designs and manufactures industrial and commercial screens for more applications in more markets than any other organisation in the world. Applications Engineer Michael Ekholm manages projects ranging from keeping drinking water clear of contaminants to filtering sugar and purifying oil and gas supplies.

Ekholm uses Mathcad on a daily basis to design, test and document new projects, collaborate with teams and create applications used around the globe.

Part of Mike's job is to work with public water supplies to create applications for keeping debris and aquatic life out of drinking water.

To do this effectively, Johnson Screens pioneered a 'passive' intake screen system that eliminated moving parts and represented a breakthrough in surface water withdrawal.

This unique approach removes common problems such as heavy debris plugging an open system or the destruction of fish related to using the traditional complex, moving screens.

By reforming the water intake mechanisms, Johnson Screens creates highly efficient intake systems and fish diversion screens without the potential for mechanical failure.

Presenting official calculations that have been certified as accurate with the stamp of a professional engineer is a requirement for the water process industry, and in most of Johnson's other markets as well.

The accuracy and presentation quality of the technical information that a calculation tool provides can define a company's success.

Ekholm uses Mathsoft's Mathcad as his 'daily desktop destination,' leveraging its range of integrated tools to tackle anything from everyday calculations to the tracking of major projects with colleagues.

Mathcad enables Ekholm to maintain control of a single project without having to move between many applications, ensuring a high quality of data that cannot be compromised with conversions.

Mathcad's intuitive 'live whiteboard' style of mathematical notation and calculation means Ekholm can compute solutions as fast as he can type in equations.

This is critical to Ekholm because it saves him time.

With Mathcad, he is able to quickly map out a design and test its abilities, making adjustments along the way that seamlessly re-calculate the design applications.

'We receive many requests for projects-large and small-every day,' said Ekholm.

'It's rare that I get to work on only one design at a time, making it essential that I have a tool that provides the flexibility and intelligence to track my calculations and share my work with my colleagues'.

Team collaboration is extremely important to Ekholm, who often manages multiple projects with his peers.

Mathcad lets him document, track and share his work, ensuring consistency during a project and the freedom for him and his colleagues to work at their own pace.

'I depend on Mathcad to be my tool for everything I do during the design process, from planning and executing our technical calculations to reporting'.

By using Mathcad, Ekholm is able to simplify the design process to create, test and publish his projects.

Ekholm appreciates the Mathcad capability to interface and integrate his calculations with his other desktop tools, such as TK Solver, to gain the advantage of timesaving and a seamless design process.

Ekholm uses Mathcad reporting features to hide proprietary work and calculations when sharing documents outside of the office and making professional presentations to his clients.

'We conduct all team calculation work and reporting with Mathcad,' Ekholm said.

'It makes the process so streamlined that I can't imagine work without it'.

Mathcad is supplied and supported in the UK and Ireland by Adept Scientific plc.

The Filterpump has a 250 micron fixed intake screen, continually backwashed by internal rotating jets powered by a dedicated impeller, keeping the screen clear even in highly contaminated fluids.

The Rotorflush Filterpump is a revolutionery new product, a submersible pump with an integral self cleaning intake filter. The pump has a 250 micron fixed intake screen, which is continually backwashed by two internal rotating jets powered by a dedicated impeller, keeping the screen clear even in highly contaminated fluids. With no external moving parts, even fluids containing string, plastic bags or sanitary products cannot cause blockage.

In addition the pump produces a filtered output, which will not block nozzles and valves in upstream equipment.

Huber Technology UK Ltd are a major supplier of inlet screens for sewage treatment works.

They wished to use the in-flowing sewage as a source of wash water for their screens.

Previously potable water had been used.

The Rotorflush Filterpump provided the ideal solution, an easy to install, submersible pump and self cleaning filter in one unit.

Not only was the unit able to work directly in sewage without blocking, an essential requirement on unmanned sewage treatment works, it also provided a filtered supply that would not block the nozzles and solenoids on their screening equipment.

A number of units have been supplied to Huber over the last 9 months with great success.

A fully automatic Cross filter has been installed at the Thames Water Deephams STW in North London to enable treated final effluent to be used to clean recently upgraded works inlet screens.

A fully automatic Cross filter has been installed at the Thames Water Deephams sewage treatment Works in North London to enable treated final effluent to be used to clean recently upgraded inlet screens at the head of the works. Using final effluent for this task saves the considerable expense of using fresh town water, but it is essential to ensure that it doesn't contain any suspended solids that are large enough to block up the spray nozzles. At Deephams this is achieved by using a Cross Phoenix filter, rated at 400 microns.

Sewage treatment at Deephams has been upgraded to meet strict new Environment Agency consent targets.

Treatment entails screening and grit removal, primary sedimentation, aeration and final sedimentation at a designed daily capacity of up to 460,000 tonnes (cubic metres).

A proportion of the final effluent has always been used as the source of cooling water in the site's powerhouse, where electricity is generated from methane gas produced during the treatment processes.

The same water supply is now also used for inlet screen cleaning, passing through the Cross filter on its way from the powerhouse to the head of the works.

Despite its compact size, the Cross Phoenix filter is capable of filtering at a flow rate of up to 85,000 litres per hour, without interruption, even during automatic backwashing.

Filtering is performed by patented Cross 'zero gravity' coils, six of which are fitted in the Phoenix.

Backwashing is triggered by an adjustable pressure differential signal, supported by a time lapse back up.

Each coil is individually backwashed in a sequential programme, which reverses the flow, enabling the coil to open slightly along its entire length, ensuring that the debris build-up is completely flushed away.

Since only one coil is backwashed at a time, five coils always remain on-line, maintaining an uninterrupted flow through the system at all times.

The complete backwashing cycle takes less than a minute and uses a minimal amount of water.

Harpscreen piano wire screens, a proven choice for all makes and models of screening equipment, now offer an alternative to traditional steel crossbands: plastic crossbands can now be fitted!

Harpscreen piano wire screens, a proven choice for all makes and models of screening equipment, now offer an alternative to traditional steel crossbands. Both round and square plastic crossbands can now be fitted to suit an even wider variety of applications and needs. All crossbands on Harpscreen piano wire screens are easy to install and fully moveable for ease of positioning.

The screens are individually tested at the point of manufacture and can be supplied in an extensive range of sizes, with next day delivery available from stock for standard products.

To ensure that all applications are catered for and maximum productivity and efficiency are achieved, the screen wire apertures range from 1mm up to 50mm.

Only the highest quality high tensile piano wire or stainless steel wire is used to give extended trouble-free operation.

The wires range in size from 0.65 up to 5mm diameter and can be provided in four duty ratings from heavy up to XXH.

Piano wire cassette and conversion kits are also available.

They are individually manufactured to suit specific screen-boxes and employ a high quality tensioning system that readily houses a variety of screens including flexi-harp and square mesh.

Another recent addition to the range of accessories for Harpscreen piano wire screens is the Harpscreen Multiframe.

Using the company's modular Multimat piano wire screen, the main benefit is that there is never a need to replace a full size screen as each worn piano wire section can be replaced individually without removing the frame.

Yorkshire Water reports that 8 Mono Industrial E Range pumps fitted on the autodesludge process at Beverley WwTW have completed 18 months of trouble-free operation following their installation.

Yorkshire Water reports that eight Mono Industrial E Range pumps fitted on the auto desludge process at Beverley WWTW have just completed eighteen months of trouble-free operation following their installation. The pumps replaced competitive products, which had to be removed after they had suffered constant blockages and unreliable service. Two Mono CE071SJR4 progressive cavity pumps are fitted to each of the four primary settlement tanks at Beverley WwTW as part of the framework agreement with Yorkshire Water, and were specified with minimum maintenance requirements and low whole of life costs uppermost in mind.

The competitor pumps had only been in operation for approx 1 year before Yorkshire Water had to resort back to manual desludging of the tanks because of constant blockages and this was proving to be cost prohibitive.

The pumps draw sludge from the bottom of the sludge hopper under the head of water in the primary tanks and transfer it to the sludge wet well.

The previous equipment was situated in a confined place below ground, which proved inconvenient given the levels of maintenance subsequently required.

The Mono pumps are situated above ground to improve access if required, although in the event they have not suffered a single blockage in the first year and a half of operation.

The primary sludge has a dry solids concentration of 3 - 8% and all the eight pumps have a transfer rate of 15m3/h.

Powered by 3kW motors, the pumps internal fluid velocities are designed to be kept within operating limits to guarantee a long and relatively trouble free life - an assumption which has been borne out by experience.

Other characteristics which demonstrate the far sighted Yorkshire Water approach to lowering fixed costs and controlling long term budgets is the decision to have the pumps fitted with mechanical seals, rather than packed glands and to be equipped with overpressure and dry run protection systems.

Commenting on the Yorkshire Water experience of the E Range pumps at Beverley WwTW, Area Operations Supervisor David Sutton said, 'The Mono equipment is trouble-free in operation and has significantly reduced the levels of maintenance required.

On this basis it entirely justifies the decision to purchase equipment with a higher specification because it gives us a lower cost of ownership'.

Mono Pumps are designed to give least whole life costs through component life, reliability of operation and ease of maintainability.

Rotor and stator materials are selected and coated according to the end users industry to ensure that the type of wear likely to take place is accounted for and the best combination of materials is supplied.

Differential pressure per rotor stage is kept to a minimum.

This reduces the load at the rotor/stator seal line and consequently reduces wear.

Pump speed is selected according to the end product and is kept to the optimum and as the E Range pumps are fitted with the Mono Flexishaft coupling, wearing parts are minimised and lubrication is unnecessary, eliminating product contamination in the unlikely event of joint failure.

Westfalia Separator announces the launch of the new UCD 345 dewatering decanter, aimed primarily at the municipal waste water treatment plants or for use in larger industrial waste water facilities.

Westfalia Separator announces the launch of the new UCD 345 dewatering decanter. With a bowl diameter of 340mm and a dewatering capacity up to 15M3/hr it is larger than the popular 'Crocodile' UCD 305. It is aimed primarily at the municipal waste water treatment plants or for use in larger industrial waste water facilities.

The UCD 345 is the fifth member of the new CD Force family and its performance approaches the large 400mm dia machines while being very compact.

As with all the range the new UCD 345 has been designed with customer benefits in mind including improved price/performance ratio, greater ease of access for maintenance and cleaning, user friendly operation and lower energy consumption.

The entire CD family features the 'Twin Shell' concept, which means that the product discharge catchers and housings are not connected to each other but form self contained units: this translates to lower noise levels and less air circulation.

As with other CD Force units, the UCD 345 has the main motor located beneath the housing while the secondary motor is mounted on the frame.

The V belt drives operate without an intermediate clutch.

The compact design facilitates fast replacement of bowl, scroll and bowl bearings, either individually or as complete assemblies.

Exchanging a regulating plate only takes a few minutes.

The new CD345 has been designed for minimum downtime and ease of service and with a significant reduction in the number of parts.

These state of the art decanters offer trouble free operation in municipal and industrial waste water treatment.

The removal of phosphate from the effluent of a sewage works is an essential part of the urban waste water directive: Partech has trialled closed loop feed forward control of an inlet dosing system.

The removal of phosphate from the effluent of a sewage works is an essential part of the urban waste water directive. Many treatment works have phosphorous discharge consent, but with the increasing use of detergents containing phosphate, the problem of staying within consent is growing. Phosphate removal is carried out by dosing chemicals, normally iron salts or occasionally aluminium salts, at a rate determined by a preset diurnal profile derived by analysing a series of samples over a period of time.

Over the past 18 months, Partech Instruments has trialled closed loop feed forward control of an inlet dosing system for the removal of phosphate at three sites.

The results of the trials demonstrate that this approach is reliable and cost-effective, and can assist in making considerable savings in chemicals.

The natural removal both of nitrate and phosphate where applicable is the method of choice.

However, in most cases it is not possible and it becomes necessary for the works operator to resort to chemicals, with Ferric Chloride and Ferrous Sulphate being the most commonly used.

Where the efficiency of iron is much reduced, aluminium salts has been applied successfully, and works normally in conjunction with an iron salt.

In all cases, the amount of chemical used is critical for the performance of the works, cost control and meeting the metal discharge consent.

Dosing iron salts at the front end of a works requires a level of control to ensure that the pH of the influent is not made too acidic as this has a detrimental effect on the nitrifying process.

Historically, the iron dosing rate was calculated by taking a series of samples throughout the day and having them analysed to derive a diurnal profile.

This profile is entered into the dosing system such that a specific volume of iron is dosed at the time intervals used and this is then employed to 'control' the dose.

The Partech MicroMac sampling system is based around analysing ortho-phosphate, as opposed to total phosphorous.

This is because the ortho-phosphate chemistry is simple and fast, unlike the total phosphorous chemistry, which is complex and can be very slow.

Iron reacts directly with the soluble phosphate, which is almost totally in the ortho-phosphate form and the total phosphorous is largely in the bound form with the solids and is therefore flocculated by the iron with the solids.

It is also to be noted that in order to analyse for total phosphorous, it would be necessary to analyse an unfiltered sample, which on the inlet would be impossible.

The ortho-phosphate chemistry used is the standard ascorbic acid method, with the analyser calibrated using a 10mg/l as P standard and capable of detecting up to 25mg/l as P.

The analytical cycle time for this analysis is approximately five minutes.

Throughout the 18-month trials period, Partech gave great attention to designing a sampling system that would be low maintenance and ensure reliable crude sewage sampling.

The sampling system is a critical part of the control system and requires an optically clear sample to determine accurately the ortho-phosphate level.

The finished design copes with low flow and low sample levels, grit, ragging and turbulent flow.

In addition to low maintenance, the simple design helps with operator confidence and keeps the cost to a minimum.

The advantage of determining the phosphate level on the inlet is that the dose rate of the iron or aluminium salt can be calculated and the dosing system controlled using the combined flow and phosphate concentration.

The combined output generated allows the operator to adjust the dose for site-specific conditions that allow the 'P to Fe' ratio to be adjusted until it is optimised.

This optimisation requires the monitoring of the final effluent to ensure that the phosphate levels are within the Environment Agency consent; once the optimisation has been done there is no need to monitor the final effluent.

By using feed forward control the dose responds to actual changes in phosphate levels and provides an active dosing regime whereas the commonly used 'diurnal profile' cannot respond to changes in the inlet and can be either over dosing or under dosing both of which have financial consequences.

Three water companies provided sites for the Partech evaluation programme, these being Thames Water, Southern Water and Anglian Water.

The Thames Water site, with a Population Equivalent (PE) of 39,000, had a pumped inlet and a Gee and Co system dosing ferric sulphate controlled by a predetermined diurnal pattern.

The inward flow varied between 40 and 200 litres per second and upstream of the measuring point was a weir below which were two 'sandbanks' which release significant amounts of grit during high flow.

The trial unit was positioned above the inlet channel some 20m upstream of the dosing point and the sample pump was located directly below the trial unit.

The flow signal was obtained from the existing Warren Jones flow meter.

After four months the system was reliably analysing crude sewage for ortho-phosphate and when combined with the inlet flow, was successfully controlling the dosing system.

During the initial stages, Partech was able to demonstrate a saving of some 25% of the iron dosed when compared against the diurnal dosing regime.

This was later improved by a further 8% by adjusting the 'P to Fe' ratio.

The second trial, with Southern Water, took place at a site with a PE of 100,000 and a standard inlet channel equipped with well performing screens and de-gritting.

The flow rate ranged from 100 litres per second to 300 litres per second at storm flow and the existing dosing system operated using a predetermined and optimised diurnal pattern was a Chemfeed unit with full dosing control computer.

The works also had tanker waste delivered at irregular intervals, which had some effect on the incoming phosphate levels.

The trials unit was installed above the inlet channel about 10 metres upstream of the dosing point.

After just a few weeks the Partech system had provided several daily profiles and was shown to agree with the laboratory results.

The positive results of this trial was the confirmation of the results and with a redesigned filter coping well with the sample, the maintenance interval was increased to greater than 8 weeks.

The third trial was at an Anglian Water site with a PE of 45,000 and contained a balance tank on the pumped flow inlet.

The dosing system on site was a Gee and Co unit with a Chemtrol computer unit for the dosing control and the unit was set up to run on a dosing profile.

The flow into the works was highly variable between 20 - 180 litres per second with a common discharge channel to 3 PSTs.

The dosing point was in a chamber prior to the channel to the PSTs and the trials unit was mounted above the common channel prior to the ferric sulphate dosing point.

This site had not been optimised prior to the trial starting and the profile being dosed was a flat dosing rate with little variation.

After an initial period of running baselines to look at the diurnal pattern, the Partech analyser system was attached to the dosing system and a controlled trial was carried out.

During this trial the amount of iron dosed was reduced by some 47% against the flat dose rate that was initially controlling the system.

The sampling system worked very well and it was found that the filter did not require cleaning for a period of three months.

With the cost of the control system being in the region of GBP12k - 17k, depending on site conditions, a saving of 18% per annum at a site with a dosing rate of approximately 400 litres per day and at a cost of GBP50 per ton, the payback period is less than 12 months.

The use of an 'active' control system at the inlet to a works can have the following effect.

* Tighter and more effective control of the chemical dosing, with response to routine and non-routine events.

* Saving of dosed chemical expected to be in the range 10 to 40% depending on the status of the works as far as optimisation is concerned.

* Less likelihood of consent failure for both residual chemical - iron or aluminium - and phosphate.

* Reduced sludge production.

* Reduced potential for corrosion of the works due to over dosing of iron.

* The control system will have a payback period relative to the size of the works and volume of iron being used and is not expected to be viable on a small works.

* A reliable, robust dosing control system now exists.

Submersible mixers made by Landia have successfully completed eight years of untroubled operation at one of the largest wastewater treatment plants in Germany.

Submersible mixers made by Landia have successfully completed eight years of untroubled operation at one of the largest wastewater treatment plants in Germany. At the Bremen-Seehausen WWTW, which handles approx 62.8 million m3 of wastewater every year, Landia mixers have been working non-stop, 24-hours per day, seven days per week for a full eight years. One of the benefits that the 26 submersible Landia POP-I mixers bring to the plant is the highly efficient mixing of wastewater with activated sludge, which has to meet stringent environmental requirements laid down by German law.

'The mixers have operated satisfactorily through the years and so far we have had no problems', says Mr Sven Wedderman, Head of Process Technology at the Bremen-Seehausen WWTW (hanseWasser Seehausen WWTP).

The utility value of the biological process and the quality of the treated wastewater at Bremen-Seehausen depend very much on the reliability of the Landia mixers, which apart from routine servicing, have proved virtually trouble-free.

Landia POP-1 mixers continue to ensure that all bacteria and organic matters in Bremen-Seehausen are equally suspended throughout the whole tank volume, creating optimum homogenised wastewater for a biological process that has a cleaning performance of 91% for COD, 92% for phosphorous and 79% for nitrogen.

The slow-speed Landia POP-I 1.5 kW-150 rpm flowmakers are also very energy efficient, designed to to provide a gentle treatment of the medium with thorough, efficient mixing, achieved by a low number of propeller revolutions.

This greatly improves flocculation and ensures the biological balance.

The low number of revolutions also creates less turbulence on the surface and thus prevents oxidation in the anoxic tank.

A submersible, free-standing Landia Air Jet has significantly helped the owners of a popular tourist attraction in Ireland with the management of the site effluent treatment plant.

At one of Ireland's most ancient and stunning caves, a submersible, free-standing Landia Air Jet has significantly helped the owners of the popular tourist attraction with the management of the site effluent treatment plant. Aillwee Cave, which is situated in the Burren in County Clare, attracts 180,000 to 200,000 visitors every year - but as with many tourist attractions, visitor numbers can be unpredictable, causing irregularities for their effluent plant balance tank, as Nick Johnson, managing director, explains: 'When the plant was running at typical levels it worked quite efficiently', he said, 'but when it wasn't being fed continuously with the right amount of liquor, we had problems'. He added: 'The Landia Air Jet has successfully kept the balance tank aerated and homogenised, giving us much better management of our effluent treatment plant, as well as removing any unpleasant odours.

It is fair to say that without the Landia aeration equipment, which is proving very reliable, we may have been forced to change the effluent plant completely'.

The Landia DG-I Air Jet (3.0 kW), which was supplied through Fergon Enterprises, is a highly effective non-blocking system that is very easy to install in aeration or storm water retention tanks, and requires no ancillary equipment.

One of the key attractions on the inspiring, almost moonscape Burren, which is a paradise for geologists, botanists, ornithologists, speleologists and archaeologists, Aillwee Cave treats visitors to a guided, informative walk through 1.3 km of passageways, where they can see animal remains, waterfalls and numerous spectacular cave formations.