Category Archives: Fine Bubble Aeration

‘Out with the Old and in with the NuDisc’ at RSPB Headquarters, Bedfordshire

This month the RSPB have a shiny new KEE Wastewater Treatment Plant installed. This replacement KEE NuDisc® 20HR model and Twin Pump Station replaces their old G7 BioDisc Unit and Pump Station. The old plant was no longer suitable for their headquarters in Sandy due to the increasing staff numbers based on site and visitors attending the nature reserve.

The KEE NuDisc 20HR and Twin Pump Station that replace the old BioDisc

The KEE NuDisc 20HR and Twin Pump Station that replaces the old BioDisc

 

 

The old G7 BioDisc and Pump stations no longer fit for purpose

The old G7 BioDisc that’s no longer fit for purpose

For more information on KEE’s Wastewater Treatment Plants, or potential existing plant refurbishments or upgrades, please visit our KEE Process website or call us on 01296 634500

Specialists in Domestic & Industrial Wastewater Treatment

KEE’s Commitment to Environmentally Sustainable Procurement and Fair Trade

One of KEE’s core company values focuses around Environmental Sustainability. As a business, we recognise our obligations to consider the environmental impact the materials we source and the products we produce have on the environment and, we aim to reduce the impacts & ensure environmental sustainability.

Fairtrade is about better prices, decent working conditions and fair terms of trade. It’s about supporting the development of thriving communities so that they have more control over their futures and protecting the environment in which they live and work.

KEE Process Ltd & KEE Services Ltd aim to ensure that we will play our part in reducing risks:

  • Use fewer resources and less energy through continuous improvement and the use of innovative solutions.
  • Procure all timber and timber products from legal and sustainable sources, and procure with a preference other construction materials from recognised responsible sourcing schemes.
  • Specify and procure materials and products that strike a responsible balance between social, economic and environmental factors and generate benefits to society and the economy.
  • Use resource-efficient products and give due consideration to end-of-life uses.
  • Influence, specify and source increasing amounts of materials which can be reused, and consider future deconstruction and recovery of resources to embrace the circular economy to leave a sustainable legacy across the built environment.
  • Where possible, provide opportunities for small and medium sized enterprises (SMEs) increase the use of social enterprises, support local employment, diversity and training and work collaboratively with the voluntary sector, especially those near to our offices and operations.
  • Ensure that fair contract prices and terms are applied and respected, and that ethical, human rights and labour standards are met, in line with the United Nations Global Compact principles.
  • Source goods, works and services that embody our environmental policy, health & safety policy and support the delivery of our Sustainable Development Strategy.

We believe our commitment to these values is one of a number of ways in which KEE, everyone within the company, and all our customers can demonstrate social, environmental and economic responsibility. Our business like all others changes and evolves over time, but our core values remain the same.

For more information, please call 01296 634500 or visit our website.

 

 

 

 

Benefits of a Planned Preventative Maintenance (PPM) approach to managing your Wastewater Treatment Equipment.

“ A maintenance strategy is necessary to ensure the smooth running of business operations. As well as giving a business better control over its asset and maintenance costs, a clear maintenance strategy helps to ensure statutory compliance and adherence to company policies. ”
Ian Short. KEE Services Business Development Manager.

An unplanned, reactive maintenance approach may lead to lower maintenance costs up front and less time spent on planning and performing maintenance in the short term, but that’s about where the benefits end. The cost of replacing failed components, equipment and emergency call out work at short notice and/or outside of normal operating hours costs much more when the situation arises. Therefore not proactively planning your maintenance tends to be more costly in the longer term and causes much more disruption to your business fixing the problem once it has occurred.

Why maintain your equipment?

There are a number of key reasons a business should take the time to consider the maintenance needs of their Wastewater Treatment equipment:

  • Regulatory compliance
  • Environmental surroundings
  • Ensuring a pleasant
  • Health and Safety obligations
  • Budget management
  • Reliability of equipment
  • Optimising asset use
  • Energy management
  • Business need

Proactive maintenance keeps you one step ahead of your equipment needs. In the same way that you would take your car for regular servicing rather than waiting for it to break down and incurring a large repair bill, it’s strongly advisable to maintain your equipment on a systematic basis.

PPM Strategy

PPM involves setting a maintenance schedule based on either calendar time or asset hours. This should also take into account factors specific to your business usage such as the environment in which it is operated and any legal waste consent requirements applicable.

A maintenance strategy takes the business’s maintenance aims and translates them into actions to support the company’s obligations, requirements and intentions. The strategy should include the following elements:

  • Setting of an appropriate budget
  • Carrying out risk assessments of equipment and processes
  • Establishing detailed regulatory, health and safety needs
  • Designing a resource and efficiency management strategy
  • Ensuring adherence to waste permit limits set by Environmental Agency.
  • Assessing the age of the equipment and whether any plants require refurbishment to extend plant longevity and minimise reactive maintenance.
  • Ensuring all maintenance work is completed by certified, registered companies appropriately insured and trained to complete the work.

PPM Programme

PPM is usually carried out with the support of a certified partner specialising in asset maintenance such as ourselves. Using our experience, we can provide a better insight into the condition of your assets. As a result, you can adopt a proactive maintenance programme designed specifically for your business and equipment thereby reducing the need for reactive maintenance.

Reactive maintenance may sometimes still be required, but a PPM plan will reduce the likelihood of this happening and will assist you in managing the maintenance budget with fewer surprises. Additionally, if a reactive engineer call out is required, KEE can check when the next planned Service Visit is due at your site and, where appropriate, arrange for the engineer to complete the ‘PPM Service’ on the plant at the same time, therefore minimising call out charges and site visits costs.

PPM also gives much greater control over the impact maintenance has on business operations because you can schedule when you wish maintenance to be completed based on when it will cause minimum disruption. For example, you can arrange a maintenance visit for a specific day when employees are available to provide access etc. Seasonal requirements can also be taken into account to ensure your Wastewater Treatment equipment is serviced and in full working order when needed most.

Following a maintenance program and documenting all work carried out also supports your legal compliance and provides evidence thereof (should it be required) in the event of system failure leading to harm or environmental damage.

KEE Services maintain all types and makes of Wastewater Treatment equipment. Please contact us on +44 (0) 1296 634 500 or visit our KEE Services website for more information on designing a PPM programme to suit your requirements.

Over the years, KEE Process Limited has produced and delivered numerous Wastewater Treatment Plant projects in Northern Ireland and Ireland, using local M & E contractors.

In the Republic of Ireland and Northern Ireland many of KEE’s projects have been using local M & E contractors who offer total supply and installation packages to clients, with fully comprehensive after sales support. Some of these projects include plant built for the following sites:

1.   Large Hotel, Co. Wicklow.

The hotel already had a wastewater treatment plant but they decided to build a new 40-bedroom lodge on site and therefore needed a plant to treat all the existing flows plus the flow from the planned expansion. The main requirements of the client were:

The final effluent required Total Nitrogen and Phosphorus reduction and needed to consistently comply with the onerous discharge license of BOD < 20 mg/l, SS < 30 mg/l, COD < 80 mg/l, NH4-N < 20 mg/l, NO3-N (Nitrate Nitrogen) < 5 mg/l, Phosphate as PO4 < 12 mg/l, FOG (fat, oil and grease) < 20 mg/l and Detergent (MSAS) < 1 mg/l.

The plant was to have low operational and maintenance costs.

The plant supplier was to be able to provide complete service to include planned preventative and emergency maintenance, process and operation maintenance and effluent sampling.

The KEE’s proposal included supply, delivery, installation and commissioning of a 60m3 primary settlement tank, Module DC16 Rotating Biological Contactor and ST6 hopper bottom GRP final settlement tank. All this equipment was factory built and delivered to site ready for installation on concrete slabs.

This plant was installed and commissioned in 2003. It has operated extremely well mechanically and has delivered excellent process performance since start-up. The total electricity costs for the plant is less than EUR1,000 per annum.

2.   Golf Club, Co. Cork

This was a design and build turnkey contract and KEE who were process partners in the project. The discharge license was direct to the watercourse and specified a BOD < 20 mg/l, SS < 30 mg/l, NH4-N < 20 mg/l & Phosphate as P < 2 mg/l.

KEE supplied their compact single piece NuDisc® Model 1200.

3.   Golf Club, Co. Dublin

During the refurbishment of the clubhouse, on-site sewage treatment plant and disposal systems were required. The discharge license specified a BOD < 20 mg/l, SS < 30 mg/l & NH4-N < 10 mg/l, NO3-N (Nitrate Nitrogen) < 15 mg/l, Phosphate as PO4 < 5 mg/l and FOG (fat, oil and grease) < 10 mg/l.

KEE Process Ltd designed the process and supplied and installed a single-piece compact packaged plant NuDisc® F13N with inbuilt de-nitrification stage and phosphate removal stage.

This contract also included the design and installation of an inlet pumping station and a sub-surface percolation area.

4.   County Council, Ireland

This was an installation for a municipal treatment works for a Southern Ireland County Council for 1000 PE. The flow to the works are combined with surface water and municipal wastewater with a discharge license for BOD < 20 mg/l and SS < 30 mg/l.

KEE supplied their packaged modular treatment system and the contractor led the contract for installation and commissioning.

For more information on our Wastewater Treatment Technologies, please phone on 01296 634500 or visit our KEE Process Website.Specialists in Domestic & Industrial Wastewater Treatment

 

Private Residential Golfing Community in New York State Selects KEE Process Managed Flow® Wastewater Treatment Process

Bristol Harbour is a private residential golfing community in the Western Finger Lakes of New York State, USA.

Having experienced ongoing problems with their existing wastewater treatment plant, the community approached KEE Process Limited’s North American partner, Waste Water Solutions International Inc., for help.

After suffering regular mechanical failures, deviations in effluent performance and high operating costs, the community recognised the need to upgrade their aeration plant. The new system would also need to cope with the planned expansion of the development and meet the State Law’s stringent treatment requirements.

The KEE Process Managed Flow® Process was selected because of its ability to continually produce high quality effluent and its low operator costs and maintenance. The system was also ideal for the site’s limited space and environmentally sensitive location.

To provide flexibility two streams were installed. The technology chosen included:

  • A balancing tank
  • KEE Process Managed Flow Rotating Biological Contactor (RBC) – Model DN-19-S
  • KEE Process Final Settlement Tank (Model ST9) with automatic pump assisted sludge return system and gravity sand filter with backwash capability.

This technology was designed and specified to provide for the current and future expansion of the community.

The KEE Process Managed Flow RBC Model DN-19-S and a KEE Process Final Settlement Tank Model ST9 with automatic pump assisted sludge return system and gravity sand filter with backwash capability installed at the Bristol Harbour private residential golfing community in the Western Finger Lakes of New York State, USA.

The KEE Process Managed Flow RBC Model DN-19-S and a KEE Process Final Settlement Tank Model ST9 with automatic pump assisted sludge return system and gravity sand filter with backwash capability installed at the Bristol Harbour private residential golfing community in the Western Finger Lakes of New York State, USA.

For more information on our Wastewater Treatment Technologies, please phone on 01296 634500 or visit our KEE Process Website.

Looking after your Sewage Treatment Plant this Christmas

With the festive season upon us, guests arriving and the celebrations in full swing, please do keep in mind what you and any visitors are pouring or flushing down your drainage system into your Sewage Treatment Plant

Do’s

  • Follow manufacturers’ recommended doses for your water type when using household cleaning products. Soft water requires far less detergent concentration than hard water.
  • Try to use cleaning products little and often so your treatment plant is not overloaded.
  • Use liquids (not powders) in washing machines and dishwashers. Powders re-coagulate into clumps and can cause blockages.
  • Try to spread your clothes washing throughout the week.
  • Stick to the same washing, dishwasher and other cleaning products as the bacteria will work more efficiently with products it is used to treating.
  • Think before you put anything down the sink, toilet or drains.
  • Desludge your plant when required.

Click HERE to view our one-page KEE EXPERT guide on proficient desludging and how regularly your unit should be desludged.

  • Ensure only toilet paper is flushed down the toilet and used in normal quantities.
  • Leave your plant switched on while you are away or on holiday. Switching off your plant can cause damage to the motor and moving parts as well as kill the biomass.
  • Compost all your organic food waste or use your local council bio–degradable waste recycling service (where applicable) to dispose of organic waste. Do not flush organic waste down the sink or drain.

Don’ts

  • Don’t put sanitary towels, tampons, cotton wool or cotton wool buds, incontinence pads or any baby, cleaning or facial wipes down the toilet.
  • Don’t flush rubber products or other non-biodegradable products down the toilet.
  • Don’t pour fat, grease or cooking oil down the sink or drains. Fats suffocate the bacteria and inhibit the biological process. Everyday products such as milk, wine or beer increase the organic load and should also not be disposed of through the wastewater system.
  • Don’t use neat disinfectant or bleach. KEE recommends that these products are only used at the minimum concentration possible, as they can restrict the biomass growth within the plant.
  • Don’t tip medicine, mouth wash or any chemicals such as photographic fluid or garden products (e.g. Insecticides, weed killers and fungicides) down the drains as they will damage the biological treatment process.
  • Don’t pour DIY products (e.g. paint, thinners, turpentine and white spirit etc.) or car fluids such as engine oil, anti-freeze, brake fluid etc. down the drains.
  • Don’t allow rainwater, groundwater or large volumes of water (such as those from a swimming pool or Jacuzzi) into the plant. Chlorine kills the bacteria and the excessive water will increase the flow rate through the plant, not allowing sufficient treatment time.
  • Don’t fit a waste disposal unit under your kitchen sink. Disposing of organic matter through the treatment system increases the organic load, creating bacterial overgrowth which will inhibit the treatment process. Only use a waste disposal unit if your plant is specifically designed to accept higher organic loads.

For more information or to arrange a tankering visit, please call our KEE Services team on 01296 634500 or visit our KEE Services website.

KEE News – It’s all change in 2020! What do the latest septic tank regulations mean for you?

“Septic tank regulations” – I agree it’s not an opening phrase that would make many people read on, but if you have a septic tank on your property, then you might just need to read on.

Given what goes into a septic tank, it’s understandable why the Environment Agency is keen to make sure that it stays in the tank, instead of in the local stream. So, there are a lot of rules and regulations surrounding septic tanks, from where you can put them to where and how the water can be discharged.

The latest regulations came out in 2015, and are called `General binding rules: small sewage discharge to surface water’.  It doesn’t exactly trip off the tongue, but it’s a very important document for many property owners and worth a read.

In the past, you could discharge the separated waste water from your septic tank in one of two ways:

  1. To a drainage field or soakaway system – here, the waste water percolates through holes or slots from the pipework, into a soak away (pit filled with rubble or course stones) and then discharged into the surrounding sub-soils.
  2. To a watercourse – the waste water would flow through a sealed pipe straight to a local watercourse such as a stream or a river.

So, what’s changed?

From the 1st of January 2020, you will not be able to discharge your wastewater into a watercourse.  The reason for this is because the `quality’ of the waste water is no longer considered clean enough for our wildlife or rivers.

This isn’t an entirely a new rule as for some years now, property owners installing a new septic tanks have not been able to discharge into a watercourse.  However, if your property had an existing septic tank discharging into a watercourse, you were able to carry on unless the Environmental Agency identified that it was causing contamination.

So, if you are looking to sell your property between now and 2020 you will be required to ensure your Septic Tank meets the new regulations before you sell.

So what are the options?

There are three main ways in which you can comply with the new regulations:

  1. Connect to mains drainage system
  2.  Install a sewage treatment plant – Sewage treatment plants clean and filter the wastewater to remove harmful toxins and impurities, making the wastewater clean enough to discharge straight into a watercourse.
  3. Install a drainage field or soakaway – This will take the waste water from your septic tank, and disperse it safely into the ground without causing pollution. However, space is required as a soakaway must be located at least 5 meters away from any property and at least 6 meters away from a Public Highway.

To conclude, if you do not have the space to install a soakaway on your land and are not close enough to a mains sewage system to get connected then a Sewage Treatment Plant is your best option.

For more guidance or a quote, please contact KEE on 01296 634 500 or email sales@keeservices.com.

Dŵr Cymru commission KEE Group to refurbish and replace a non performing RBC in small Welsh Village

A very old unreliable non performing RBC unit is refurbished by KEE

KEE were commissioned to design, build, supply and carry out all civil work, to refurbish and update a very old unit which was unreliable and not performing in a very small Welsh Village.

Within the brief, KEE had to strip all the internals and fit a new unit into the existing steel tank on site, as there was no room for digging a bigger excavation.

Before - Existing unit in need of refurbishment

Before – Existing non performing unit in need of complete refurbishment.

After: New refurbished RBC unit by KEE.

After: New refurbished RBC unit designed, manufactured, supplied and installed by KEE.

For more information on KEE Refurbishment and Updates or details on any other KEE wastewater treatment equipment and systems, please refer to our website at keegroup.com or call us on 01296 634500.

 

 

KEE Triton® – Mountmellick Wastewater Treatment Plant Upgrade – The installation of new aeration and mixing units to reduce the carbon footprint and improve plant performance.

3.7kW Tritons® fixed on a tri-pontoon float. The Triton® can be bridge or side-wall mounted.

3.7kW Tritons® fixed on a tri-pontoon float. The Triton® can be bridge or side-wall mounted.

Background

Mountmellick village is located approximately 15 miles northwest of Portlaoise, County Laoise, Republic of Ireland. As with all Irish towns, Mountmellick has grown greatly over the years. The existing plant was designed and installed in the mid 1970s, with further works being added later, the last being a sludge dewatering plant.

The existing plant design consisted of:

  • A Wham Mechanical Screen
  • An Oxidation Ditch for biological treatment. A 60m long ‘Race Track’ shaped ditch, each lane measuring 7m wide. The total average depth of the ditch was 1.57m with a total volume of 1,340m³.
  • Horizontal Brush Aeration System. As was the practice during the 1970s, consisting of 4 horizontal rotors, each 2m in length
  • Two final settlement tanks and sludge dewatering works.
  • An ‘activated sludge process’for the biological treatment stage.

The Challange

The design capacity of the works was 5,000PE and the discharge consent was 20mg/l BOD (Biological Oxygen Demand) and 30mg/l SS (Suspended Solids). The brush rotor aeration capacity had proved inadequate and was supplemented by Venturi Aerators. The combined horizontal brush and Venturi Aeration systems were unable to support the process oxygen demand and could not provide the necessary velocity profile in the ditch to ensure the minimum vital mixing requirement of the ditch contents. Consequently, the plant was failing consent.

In addition to the problems associated with the failure of consent, the high power demand to run the aeration system at Mountmellick (i.e. two 7.5kW drives for each horizontal brush rotors and two 13.50kW drives for each Venturi Aerator) also made it expensive to run at existing capacity. However, the need to increase plant capacity from 5000PE to 7000PE meant that the high power supply to the existing plant provided an opportunity to review the whole process performance of the aeration system and deliver a solution to reduce carbon footprint.

KEE Process was contacted by Laois County Council, to discuss how the Triton® aerators and mixers, could overcome the current process load issue facing the Mountmelick plant and explore the option to save power and increase the plant capacity.

After discussions with Laois County Council and their consultants at Nicholas O’Dwyers, KEE visited the site to review the existing plant design and formulate a proposal.

The Solution

After further liaison and evaluation of the actual dissolved oxygen requirements, it was agreed that the plant upgrade should be carried out in two phases using the KEE Process Triton® dual mode, fine bubble aerator/mixer.

  • Phase 1 upgrade – To address the urgent need to increase the process performance of the plant to meet the required environmental discharge consent and also reduce the overall carbon footprint.
  • Phase 2 – To increase the capability to upgrade the plant capacity upgrade from 5000PE to 7000PE and reduce maintenance requirements.

Based on the current load and the 20mg/l Biological Oxygen Demand consent for Phase 1, it was necessary to install four 3.7kW Tritons® to provide the supplemental Dissolved Oxygen and all the mixing for the oxidation ditch. These four Tritons® would provide complete mixing of the ditch and generate the optimum horizontal velocity of 0.3m/s to ensure that the suspended solids in the mixed liquor remained in suspension at all times.

Treatment processing target criteria for design upgrade:

Type of wastewater                                       Municipal


Dry Weather Flow (DWF)                              1,575m3/day


Full Flow to Treatment (FFT)                        3.3 x DWF = 5,184m3/day


Total influent BOD5 load                             420kg/day


Total influent nitrogen load                        77kg/day


Oxidation ditch approximate volume       1,340m3


Treatment objectives                                   BOD5<20mg/l
SS<30mg/l
(no nitrification)


Although the stated environmental objectives did not require nitrification, we knew that the NH4-N in the influent would exert an oxygen demand due to the high retention time of 20 hours (at DWF) in the oxidation ditch. The projected AOR (actual oxygen requirement) of 959kg/day accounts for both carbonaceous BOD reduction and Nitrification. For carbonaceous BOD removal only, the AOR would be 773kg/day.

[Note: AOR is the oxygen required under field conditions of temperature, elevation, desired dissolved oxygen operating concentration].

To provide the projected AOR, eight 3.7kW Tritons® were required, in addition to the existing horizontal brush rotors which would need to be retained. This process upgrade assumed that nitrification would be accepted as a future treatment objective. If this had not been the case then the Tritons on their own would have beeen sufficient to provide all the projected Dissolved Oxhgen (DO) and mixing for the 7000PE capacity.

Supply and Installation

Of all the aeration equipment on the market, Triton® aeration units are the easiest to install. There was no need to decommission the existing plant while installation was being carried out. The Tritons® fine bubble aerators were surface mounted and therefore neither the aeration tank or the oxidation ditch needed decommissioning, emptied, refurbished, refilled and re-commissioned. Tritons® can be bridge-mounted, wall-mounted, float-mounted or guiderail-mounted for SBR configuration.

Timing was of the essence to ensure that the treatment objectives were met and therefore the equipment was ordered whilst the installation format was being finalized. At the Mountmellick site Laois County Council and Nicholas O’Dwyer used a novel adaptation to use a ‘float-mount’ option where the floats were anchored to a steel bridge across the ditch with ‘H Frames’ attached to the bridge. This gave the operators the option to have fluctuating water levels as the H frame pivoted the Triton® floats to the bridge. The existing DO probes were used to control the brush aerators through the variable speed drives and, if the DO remained high, the Triton® blowers could be similarly controlled through the DO probes. At least four Tritons® had to be operating in the mixing mode to completely mix the ditch contents and therefore for Phase 1, the control philosophy was designed only to control the Triton® blowers operation to maintain the DO at between 1 and 2 mg/l.

After the Phase 1 installation was completed and within 20 minutes of the four Tritons® being commissioned, the mixed liquor DO concentration started to rise and it was evident that the units were re-suspending solids that had been settled out in the bottom of the ditch previously. Within two days of commissioning, the four Tritons® units were achieving 1-2mg/l DO constantly, with the existing brush rotors only coming on to assist at times of heavy load when the DO concentration started to drop.

Four out of the eight Tritons® for Phase 2 were operated in aeration and mixing mode at all times and the other four Tritons® were installed to operate in mixing and/or aeration mode when required. To ensure an even use, it was also decided that the Triton® operation would be alternated in ‘duty’ and ‘assist’ mode.

For Phase 1 the installed power was reduced from 42kW to 30kW and the treatment objectives were all achieved. Furthermore, the energy efficiency gains and optimisation objectives were achieved by controlling the aeration mode to provide oxygen as and when required whilst the mixing mode was always maintained to ensure the process performance. Thus, an energy saving over 28.5% was achieved and at the same time the environmental objective for effluent quality was met.

Phase 2 was designed to deliver the energy efficiency gains and carbon footprint objectives. The 45kW total installed power for Phase 2 provided a 40% increase in plant capacity whist requiring only a 3kW increase in power.

The carbon footprint can be further reduced if, as required by the consent for discharge, nitrification of the effluent was not pursued.

For more information on KEE Tritons® or any other wastewater treatment equipment and systems, please refer to our website at keegroup.com or call us on 01296 634500.

3.7kW Tritons® on a tri-pontoon float in position and fastened to the access gantry. The Triton® can be bridge or side-wall mounted.

3.7kW Tritons® on a tri-pontoon float in position and fastened to the access gantry. The Triton® can be bridge or side-wall mounted.

 

 

Industrial Wastewater Disposal and Treatment Options – Back to Basics – A Practical Approach from KEE Process Limited

What are the Options

Brewing, winery, soft drinks manufacture, food preparation production and packaging (baking, ready convenience meals, abattoir, meat, poultry and vegetable), dairy (milk processing, cream, cheese and yoghurt production), commercial laundries, pharmaceutical, petrochemical and many other industries are large users of water. This results in large quantities of heavily polluted wastewater for disposal.

UK Water companies and the public bodies responsible for collection, drainage and treatment of wastewater have strict controls on the quantity and the quality of industrial and trade wastewater being discharged into public sewers. Legislation supports them in this. Direct discharge to a watercourse is even stricter and is normally monitored by the National Environmental Agencies and the Environment Agency in the UK. Penalties for transgression can include prosecution, fines, financial loss and can, in some cases, prohibit operations.

Industrial wastewater discharge disposal options

Industrial wastewater discharge disposal options

Audits

It is always advisable to carry out an evaluation of the processes involved in the core business of an organisation to identify sources of wastewater. An audit would help reduce waste/wastewater and disposal costs, quantify flow rates, solids and organic loads and characterise the wastewater to provide the necessary data for analysing the available disposal options and optimise the design of any on-site treatment plant.

It is useful to be subjective when carrying out an audit to ensure that good housekeeping practices are identified to reduce unnecessary waste which would add to the costs of disposing wastewater generated on site. Process audits should be aimed at identifying the waste, excess use of water and energy. Simple actions, such as installations of energy-saving devices or taps and hose controls and careful disposal of solid waste, can produce both financial and environmental benefits. It would also help to reduce the size of an on-site treatment plant if one was planned and this would result in capital cost savings.

An audit would lead to evaluation of volumetric and organic mass loads for design purposes and would aid in characterising the nature of the waste, to optimise the design for on-site treatment plants.

Public Sewer or Watercourse

Public sewers are convenient for disposal if nearby. Quantity, strength and characteristics of the wastewater need to be considered and consented by Authorities or the Water Company in the UK. If approval is granted and the wastewater meets the criteria set, then sewer disposal would be an obvious choice, but this comes at a cost. High COD (Chemical Oxygen Demand) and suspended solids would lead to high costs in discharging to sewer and reducing these parameters could make significant savings. Partial or full onsite treatment would bring about cost savings to sewer discharge but needs justifying through quantification.

Hygiene versus Convenience

With the food processing, beverage and dairy industry, hygiene is of paramount importance. On-site wastewater treatment may be perceived by management as presenting problems although the risks are small. It is vital that the Operatives normally involved in the process part of the industry, do not need to visit the wastewater treatment plant and the risks to main operation therefore are contained and the operation of the wastewater plant becomes one of non-core features. This can be achieved by having the treatment plant operation undertaken by the maintenance department of the industry or independent operators such as KEE Process Limited who would provide a turnkey solution for designing, supplying, installing and operating a plant for a Client.

Treatment Options: Physical, Biochemical or Combination of Both

Where the decision to treat on-site has been made, the appropriate choice of plant has to be determined. Whether partial treatment or full treatment is installed is usually a matter of economics. A capital outlay is necessary and this must have an acceptable payback period. The treatment options available are Physical, Physical/Chemical, Biological or a combination of all or any of these.

On-site treatment could involve simple physical treatment to remove materials such as gross solids, FOG (Fat, Oil & Grease) and can include pH correction. The equipment may include manual or mechanical screens, grease separators or the newly introduced DISPERSED AIR FLOATATION which is simple, economical and extremely efficient and effective. A component of COD associated with these materials would also be removed by the physical treatment. With DISPERSED AIR FLOATATION up to 30% BOD, 50% COD, 60% TSS and over 90% FOG can be removed physically without the use of chemicals. Better performance can be achieved by using coagulant, flocculants and ploy-electrolytes. In most cases, partial treatment using DISPERSED AIR FLOATATION would achieve the reduction in pollution loads necessary to substantially reduce the cost of discharge of effluent to public sewer. The ownership costs (capital expenditure, servicing, maintenance and operation costs) associated with DISPERSED AIR FLOATATION are usually low. The benefits of cost savings in effluent disposal are high and the capital/operating cost of proving on-site partial treatment can be justified against the ownership costs. Given these benefits it may be sufficient not to invest in further onsite treatment for the effluent to be discharged into public sewer.

However, it may still be necessary or even desirable for the wastewater to be treated further for direct discharge to a watercourse or re-used for non-process operations within the industry. In such a case, full on-site treatment would often justify the capital and operations cost. Cost analysis must also take into account the valuable space required for location of the treatment plant on the core business site.

For disposal to watercourse, consent from the Environmental Regulating Authorities (the Environment Agency in the UK) will be necessary.

    

KEE Microfloat Unit                                                  Interior working of the Microfloat System

The full treatment options could include anaerobic fixed film technology. This is particularly suitable for high strength wastewater requiring initial partial treatment prior to sewer disposal or further aerobic treatment to produce effluent suitable for direct discharge to a watercourse. The aerobic process could include:

  • Suspended Growth Activated Sludge Process options through Extended Aeration, Sequencing Batch Reactor (SBR) or Oxidation Ditch.
  • Fixed Film Process through Rotating Biological Contactors (RBC), Submerged Aerated Filter (SAF).

Choosing the Treatment Option

The most suitable process selection would depend on many factors such as:

  • Initial Mechanical/Electrical Capital Cost.
  • Installation Cost.
  • Operating Cost including on-site attendance/labour costs, energy costs, consumables and plant operation complexities. Disposal costs of physically separated pollutants e.g. FOG, TSS and sludge in case of full Biological treatment plant.
  • Servicing, Spares & Maintenance Cost.
  • Space and Land requirements for location of the on-site treatment plant.

All the above factors should be taken into account and a discounted cash flow calculated on a 10, 15 or a 20-year replacement cycle. This should be weighed against the cost of disposal to sewer or partial treatment followed by disposal to sewer. When evaluating the disposal costs to public sewer, it is necessary to liaise with the authorities or provider of the central wastewater treatment plant, to establish initial capital cost contribution expected and the potential annual costs associated with sewer discharge over the next 10,15 or 20 years. Armed with all this financial data, the overall cost of various disposal options should be evaluated and the financial disposal option chosen justified on a payback period or the net discounted cash flow, or the simple approach of evaluating the cost of disposing a unit volume (say 1 m3) of effluent.

With so many factors to consider, such as type of treatment, if any, the process selection for partial or full on-site treatment and cost analysis to justify the most appropriate option for disposal of the effluent, it may be beneficial to use the services of a professional. An experienced independent consultant with a wide knowledge of industrial wastewater treatment processes would be the obvious choice. Some Companies do offer a wide spectrum of process options and have the necessary experience to offer turnkey solutions using the most optimised process. Such companies may have a bias towards their own technology and process if they have a limited range of process options to offer. All this should be balanced against their ability to provide project management, process design, site civil work, mechanical/electrical erection, commissioning and more importantly on-site operation with process warranties.

The KEE Group Companies, KEE Process Limited and KEE Services Limited can offer such an option. Their technologies include physio-chemical processes (Dispersed Air Floatation, simple gravity solids and grease separators), Anaerobic Reactors (for high strength wastewaters), Fixed Film (RBC and SAF) Reactors and Suspended Growth Reactors (Activated Sludge Processes such as Extended Aeration, SBR, Oxidation Ditch, Extended Aeration followed by Ultra fine Filtration), and on-site operation of the treatment plant. KEE also have a team of experienced process engineers and project engineers capable of delivering the necessary turnkey solution to suit most customers. KEE Services offer on-site plant operation with out-of-hours emergency backup through a 24hrs manned Call Centre.

RBC Modular System

Photographs showing SAF, RBC, & SBR plants below:

 

KEE EnviroSAF

Cut-away view of the KEE EnviroSAF

Oxidation Ditch with Nitrification, Denitrification

Oxidation Ditch with Nitrification, Denitrification and Aerobic Sludge Digestion.

Large RBCs for biological treatment.

Large RBCs for biological treatment.

Compact, single piece NuDisc® RBC Wastewater Treatment System.

Compact, single piece NuDisc® RBC Wastewater Treatment System.

KEE SBR Plant

The decanter and access manway of a fruit juice wastewater treatment SBR Plant.

KEE Submerged Aerated Filter Plant

Vegetable processing wastewater screening prior to being treated in a multi-stage Submerged Aerated Filter Plant.

KEE SBR Plant

Sequencing Batch Reactor (SBR) plant at a Brewery.

KEE Multi-stage Submerged Aerated Filter Plant.

Multi-stage Submerged Aerated Filter Plant. Preliminary treatment includes screening.

 

For more information on KEE’s latest NuDisc® RBC, please visit our website or call KEE Process on: 01296 634500