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[...]Sludge Drying Cost reduction on sludge transportation and disposal costs. Efficient solutions to minimise the volume of sludge for disposal Wastewater sludge is dried to minimise its mass and to save sludge transport and disposal costs. Handling and storage of dried sludge is cost effective, and any further disposal and utilisation methods are possible. The dried product can be used as fertiliser, as well as fuel – the calorific value of fully dried sludge is similar to that of brown coal. Thermal energy from different energy sources Thermal drying involves the evaporation or vaporisation of capillary water, surface water and cellular water, which requires thermal energy. Typical energy sources are the sun (solar drying) as well as site-specific waste heat (e.g. from a combined heat and power plant) or excess steam from power generation (exhaust steam from a turbine). Similarly, energy-efficient heating solutions using heat pumps can be employed. Extensive mechanical dewatering of the sludge is necessary beforehand. Efficient solutions to minimise the volume of sludge for disposal Wastewater sludge is dried to minimise its mass and to save sludge transport and disposal costs. Handling and storage of dried sludge is cost effective, and any further disposal and utilisation methods are possible. The dried product can be used as fertiliser, as well as fuel – the calorific value of fully dried sludge is similar to that of brown coal. Thermal energy from different energy sources Thermal drying involves the evaporation or vaporisation of capillary water, surface water and cellular water, which requires thermal energy. Typical energy sources are the sun (solar drying) as well as site-specific waste heat (e.g. from a combined heat and power plant) or excess steam from power generation (exhaust steam from a turbine). Similarly, energy-efficient heating solutions using heat pumps can be employed. Extensive mechanical dewatering of the sludge is necessary beforehand. Solar Drying Solar drying of sludge uses the energy of the sun as a thermal energy source. The basic principle is that the sludge is dried in a greenhouse structure with the help of a mechanical sludge turning device. Convective Drying Belt dryers work with low and medium temperature and the sludge is convectively dried with hot air, whereby it can be simultaneously disinfected. The dried product achieves a solid concentration up to 95% DS. Contact Drying Disc dryers work according to the contact dryer principle: Designed for partial drying of dewatered sewage sludge, they are heated with saturated steam and used for medium to large sewage sludge volumes in combination with fluidized bed incineration. The right drying process for every application We supply three different kinds of HUBER sludge drying systems, which differ greatly in terms of space requirements, temperature level and heating medium. Solar Sludge Dryers In a greenhouse where a mechanical sludge turner is installed, the sludge is dried to a solids content of usually 65% DS. HUBER solar dryers are used on small and medium-sized wastewater treatment plants as well as on very large plants. Convective Dryers The sludge is dried either with cold or with hot air in a belt dryer. The dried product has a solid concentration ranging from 70% DS up to 95% DS. HUBER cold air dryers are designed for small sewage treatment plants while the medium temperature belt dryer are most suitable for medium to large treatment plants. Contact Dryers The disc dryer is a contact dryer designed for the partial drying of dewatered sewage sludge to 40 – 45% DR and is heated with saturated steam up to max. 10 bar(a). HUBER disc dryers are often used in combination with fluidized bed incinerators for medium to large and very large volumes of sewage sludge.[...]

[...]Efficient and reliable removal of coarse material from sludge For the operational safety of sludge treatment processes, it is advantageous if the sludge is as free as possible of coarse material and disturbing solids (e.g. paper, plastics, fibres and hair). Otherwise, repeated malfunctions of aggregates and processes may occur in pumps, but also during thickening, dewatering or drying, and these can be time-consuming and costly to rectify and require increased manpower. For the agricultural recycling practised in many regions of the world, it also makes sense to separate all solids such as plastic parts for reasons of environmental protection and aesthetics. Depending on the application, HUBER has different machines for sludge screening in its product range so that the right machine and technology is available for every application, every installation situation and any throughput rate.[...]

[...]The HUBER STRAINPRESS® Sludgecleaner SP 430 was introduced 4 years ago in response to the number of projects that required multiple SP 290’s. Many of the 290’s STRAINPRESS® supplied would’ve been single units, but on the larger sites like Five Fords in Welsh Water required 4 SP 290’s, Minworth & Coles Hill in Severen Trent required 6 & 4 SP 290’s respectively. The capacity of the STRAINPRESS® SP 430 is just over double that of the SP290. The flow rate of the SP 430 with a 5mm basket @3% ds sludge is 160M3/Hr compared to 75M3/Hr on the SP 290. Cost savings can be made by: Reduced number of units (including panels), Reduced gantry size, footprint, Minimise work time onsite, Reduced maintenance and power requirements. We have supplied 407 STRAINPRESS® Sludgecleaner SP 290’s to date in the UK. Since its introduction into the UK, we’ve supplied 14 STRAINPRESS® Sludgecleaner SP 430s in the UK, the largest of those project was a recent installation in SE London (see photo). Other projects at Esholt STW for Yorkshire Water and Southend on Sea STW with Anglian Water. AMP8 will see this number of units increase due to the size and location of the projected projects. Benefits High solids removal Low energy consumption 420+ UK installations Simple robust design Fully automated operation View a video demonstrating how this sludge screening solution operates: STRAINPRESS® Sludgecleaner SP - Animation[...]

[...]Various solutions for conveying dewatered and dried sewage sludge Sludge transport plays an important role in the planning and construction of sludge drying plants. On the one hand, the dewatered sewage sludge has to be brought into the dryer and on the other hand, the fully or partially dried sewage sludge has to be transported away from the dryer. When designing a particular transport solution, important criteria include not only the required transport capacity but also the sludge properties (moist, dry, sticky, dusty,...) and the desired degree of automation. Feeding and Removing Supply and Removal of Sludge at Drying Plants Feeding drying plants with dewatered sludge: The selected drying process – solar or belt or disc dryer – determines the way in which the dewatered sludge has to be fed to the dryer. HUBER has the right conveying solution for solar drying with the Sludge Turner SOLSTICE® as well as for the Belt Dryer BT and the Disc Dryer RotaDry® . Removing dried sludge from drying plants: Depending on the degree of dryness aimed for in the drying process, partially dried or fully dried sludge is present at the outlet of the dryer. The dried sludge must then either be conveyed to silos or containers or be incinerated.[...]

[...]Mechanical sludge thickening to reduce sludge volume Before sludge with a very high water content is subjected to further treatment, it makes sense and is often necessary to reduce its volume by thickening. This also increases the solids content of the sludge. If sludge with a solids content of 1% is thickened to 6% solids, this gives a volume reduction of more than 80%. The thickening of the sludge is effected by separating sludge water; thin sludge becomes thick sludge, which is viscous but still pumpable. Sludge Volume Reduction Excess Sludge Thickening Sludge settles in gravity thickeners and is compressed by the weight of its own solids. Primary sludge from the primary clarifier of wastewater treatment plants and digested sludge from anaerobic sludge treatment thicken better statically than secondary sludge because of the higher density of their solids. Secondary sludge (excess sludge) from the secondary clarifier is preferably thickened mechanically separate from the primary sludge. Polymers are mixed into the thin sludge for flocculation before the sludge is added to the thickening machine. The sludge water released by flocculation drains by gravity through a filter medium (cloth or fine screen) while flocs are retained thereon. Mechanical excess sludge thickening is a prerequisite for the economic operation of anaerobic sludge stabilisation in a digester. HUBER offers various machines for sludge thickening differing in design, size and throughput capacity. We offer best-performing equipment for every application.[...]

[...]Birmingham, England A HUBER Technology Industrial Wastewater Case Study HUBER Technology recently completed a project for the largest confectionery manufacturer in the UK at their site at Marlbrook between Leominster and Hereford. The project for Mondelez which own confectionery brand Cadbury was delivered following good early engagement to allow a successful project to be delivered. Project Profile This project was part of the upgrade to the sites effluent treatment plant to include for a provision of sludge dewatering capability on site. It involved removal of an existing redundant DAF plant and the installation in its place of a HUBER Q-PRESS® sludge dewatering system including the provision of poly dosing equipment and associated control panels into the constraints of the existing building. HUBER Technology Supplied 1 x HUBER Screw Press Q-PRESS ® 440.2 Sludge Dewaterer 1 x Polymer dosing plant 1 x HUBER Control Panel 1 x HUBER Screw Conveyor Ro8 for sludge discharge Objective The sludge generated on site from the effluent treatment plant was originally tankered away and treated at another location. The installation of the HUBER Q-PRESS® sludge dewaterer enabled the sludge to be treated on site with just the sludge cake requiring disposal thus reducing operating costs. Solution Based on the parameters of 83 m³/week at 3% dry solids being generated at the site the Q-PRESS® 440.2 unit was selected. This allows the unit to operate in normal situations at around 8 hours per day 5 days per week. The capacity of the unit is approximately 4m³/hr if required. The sludge dewaterer was supplied complete with a HUBER designed control panel and a polymer dosing plant. Sludge cake was discharged directly into a Ro8 screw conveyor and into a skip for disposal off site. “This project was completed and delivered on time and to budget, this was achieved by early engagement with the client to ensure the right equipment was selected to deal with the sludge and was delivered successfully into the constraints of the existing building.” Richard Willis - Area Manager Product Profile HUBER Screw Press Q-PRESS®: The new generation of our well proved sludge dewatering press which is now even more efficient with an increased reliability in operation with optimised operating costs. With over 20 units operating in the UK and over 1,650 worldwide.[...]

[...]Plymouth + Maer Lane, Great Britain South West Water had been looking at alternative sludge dewatering technologies with lower TOTEX to potentially replace existing veteran centrifuge assets and tasked their preferred contractor Kier Utilities to offer solutions for the Plymouth Central and Maer Lane WwTW’s. HUBER worked closely with Kier Utilities, undertaking trials to demonstrate the HUBER Screw Press Q-PRESS® to South West Water operations who wanted to touch and feel the machine and satisfy themselves that the machine was simple, robust and easy to operate. The trial data not only satisfied South West Water that this, first of its kind in their region was what they needed but provided hard data to confirm Whole Life Costs in terms of power and chemical consumption as well as enabling accurate sizing. South West Water now have an alternative to centrifuges with a demonstrable WLC benefit together with operators who have bought into the equipment and are supportive of the change. 40 % polymer saving 80 % power savings (typical) 50 % saving on annual operating costs HUBER Technology have been working on establishing the Q-PRESS® as the go to technology for sludge dewatering. Sludge dewatering works extremely well on primary sludge and on larger sites sludge dewatering helps achieve a dryer cake, typically 18%- 30% for transportation and storage. When clients are looking at sludge dewatering, three technologies are generally considered: Screw Presses like the HUBER Q-PRESS®: Provide efficient , fully automatic, mechanical dewatering of sludge, low polymer usage Belt Presses: Although a well-established technology they are perceived to have high maintenance costs due to lots of moving parts, the belts are vulnerable to wear and blockage, spills are likely unless enclosed and they have a high wash water demand Centrifuges: Although again an established technology they tend to have high TOTEX although single units are capable of large throughputs which equals lower CAPEX, they have high power costs associated with them, high operator attendance is required, high wearing parts due to high rotation speeds and a single wash is required at the end of a shift which can overload the unit and spill out of the discharge end The HUBER Q-PRESS® has been an established product for the HUBER group and now has 1633 installations worldwide and 21 of those are UK installations. South West Water had identified sludge presses as an option to replace the centrifuge at Plymouth Central and compared HUBER’s Screw Press Q-PRESS® with another screw press technology, both technologies undertaking trials at Plymouth Central. Plymouth Central serves a P.E of around 320,000 and, being on a coastal port receives higher proportions of saline and fat than other in-land works typically do. Maer Lane serves a small population on the outskirts of Exmouth. On site previously was a 2002-centrifuge unit with 45 kW main drive and 7.5 kW back drive, which operated from around 6:30 AM to 9 PM as required, running at around 30 m³/h. HUBER’s Screw Press Q-PRESS® was demonstrated to have: Lowest NPV and WLC Lowest whole scheme capital cost Lowest operating cost Best technical support HUBER Screw Press Q-PRESS® sludge dewaterers are designed to provide efficient, fully automatic, mechanical dewatering of sludge once the diluted polymer dose into the feed sludge has been adjusted correctly to provide a suitable flocc. The enclosed design serves to reduce the odours, noise and the potential requirement for operator attendance due to spills that can be associated with other dewatering technologies on some sites. The low operating speed of the screw presses reduces wear and energy demand. For the trial to take place a HUBER Q-PRESS® 280 was tested on indigenous co-settled chemically assisted lamella-settled DensaDeg Primary and humus-like BAFF secondary sludge’s from the Plymouth Central site as well as imported similar sludge’s from the site at Maer Lane WwTW. The feed sludge during the trial varied from 4.6 to 5.15% DS with an average active polymer usage of 4.7-4.8 kg/tDS with an average cake dryness of 33% and minimum of 28.6%. As a comparison, the existing centrifuge was using around 8-10 kg/t DS of polymer based on a throughput of 25-30 m³/day to produce cake at around 23%. A sample of the trial results from a single day are shown in the table besides (click to enlarge). Following the successful trial HUBER were asked to tender for the supply of the permanent units for both of the sites at Maer Lane and Plymouth Central. The sludge feed at both sites was specified as 4.5% DS with a feed rate at Maer Lane of 10.22m 3 /hr and at Plymouth Central a feed rate of 35.55 m ³ /hr. Following a successful tender submission HUBER were awarded both projects and the HUBER Q-PRESS® 800.2 was selected for both sites with a single unit required at Maer Lane and three units required at Plymouth Central with installation and commissioning taking place in 2019. Whole Life Cost Comparison South West Water’s requirements were lowest WLC, low operator attendance, simple odour control availability and simple operation. Kier Utilities were keen to do a whole life cost comparison and using trial data and tender price as a thorough whole life cost evaluation, the following table summarises the comparison between the HUBER Q-PRESS®, new centrifuge technology and an alternative dewatering press technology, which was tested prior to HUBER. | HUBER Q-PRESS 800.2 | New centrifuge | Other dewatering press technology Average Polymer consumption|6 kg/tDS|10 kg/tDS|7 kg/tDS Power consumption (kW)|11|140|12 Cake quality (DS content)|30%|23%|25% M&E Capital Cost – HUBER Baseline 100|100%|64%|116% Total Scheme Capital Cost – HUBER Baseline 100|100%|106%|111% Annual Operating Cost Relative to current|-£298,208|-£150,666|-£223,539 NPV 20 yrs. HUBER based 100%|100%|130%|117% So what is the potential for the HUBER Q-PRESS® in the UK in the next AMP? Mike Willis, HUBER’s Business Development Director commented, “ We see the WLC benefits of the HUBER Q-PRESS® driving efficiencies in the sludge dewatering market as the cost of moving sludge is identified by OFWAT as a key efficiency driver. “ During the PR19 price, review OFWAT is expecting water companies to account for the sludge business separately from their wastewater business. The OFWAT consultation document has already highlighted the potential efficiencies through transporting sludge. This, together with the focus on regarding sludge as an asset rather than a cost is likely to result in more sludge being moved as well as focusing on the cost to transport. This needs to be done at lowest TOTEX. Reduced chemical, power and maintenance costs compared to centrifuge will drive ongoing OPEX savings year on year. Reduced odour emission rate of the Q-PRESS® compared to a centrifuge or belt press enables smaller, more efficient odour treatment plant, reduced risk of odour nuisance and improved working conditions for operators. The Q-PRESS® is available in four sizes and processes over 500kg/DS/h, providing a sludge dewatering technology that is more reliable, less fussy to operate, cheaper to buy and cheaper to operate than conventional systems- an ideal solution to meet the OFWAT objectives. The impact of the approach is considerable with a standard, modular design and approach- demonstrated by a single unit at Maer Lane and triple units at Plymouth. This has provided South West Water with a scale-able solution for their Sludge Dewatering sites. Kier Utilities and HUBER can apply the learning to the wider industry to deliver TOTEX efficiency across the industry. HUBER are involved in trials for another water company to develop a kiosk-mounted solution based on a standard off-site built HUBER Screw Press Q-PRESS®. At the beginning of March, the finalists were announced for this year’s Water Industry Awards 2020. HUBER Technology working with Kier Utilities and South West Water are delighted to have been shortlisted again for the third year running and as finalists in the following categories: Asset Optimisation Initiative of the Year - TOTEX savings at Plymouth Central Most Innovative Use of existing technology - Reshaping sludge dewatering[...]

[...]Zaragoza, Spain[...]

[...]Using the energy of the sun Solar drying of sludge uses the energy of the sun as a thermal energy source. This provides a very ecological, environmentally friendly and energy-efficient process for the treatment of sludge from wastewater treatment plants or water purification plants. The basic principle of the process is that the sludge is dried in a greenhouse structure. The sludge can be brought into the greenhouse manually, for example with a wheel loader, or automatically directly from the dewatering facility by means of special conveying units. In the greenhouse, the sludge must be distributed for optimal drying and turned over again and again. This task is performed by the HUBER Sludge Turner SOLSTICE® , which is the heart of the entire process. Sludge transport in the greenhouse is also handled by the turner. The dried sludge can then be deposited in a depression at the end of the hall or mechanically transported directly to a loading station. Solar Energy Regenerative and environmentally friendly Solar drying of sludge uses the energy of the sun as a thermal energy source. This provides a very ecological, environmentally friendly and energy-efficient process for the treatment of sludge from wastewater treatment plants or water purification plants. The basic principle of the process is that the sludge is dried in a greenhouse structure. The sludge can be brought into the greenhouse manually, for example with a wheel loader, or automatically directly from the dewatering facility by means of special conveying units. In the greenhouse, the sludge must be distributed for optimal drying and turned over again and again. This task is performed by the HUBER Sludge Turner SOLSTICE ® , which is the heart of the entire process. Sludge transport in the greenhouse is also handled by the turner. The dried sludge can then be deposited in a depression at the end of the hall or mechanically transported directly to a loading station.[...]

[...]Freystadt, Germany Due to the new regulations and legislation for sewage sludge, disposal costs have doubled for many sewage treatment plants or increased to far more than 100 € per ton original substance. The reason for the cost increase is that the standard solution for meeting the requirements of the new legislation is sludge incineration. Incineration capacities are however unequally distributed and exploited to a large extent, and transport ways have become longer on many sites. Disposal costs can be reduced if the sludge volume is reduced through drying. The Bavarian municipality Freystadt decided to build its own decentralized solution: a complete sludge treatment plant that processes wet thin sludge into dry granulate installed at the beginning of last year has since been operated fully automatically there. “Of course, we had to get familiar with the new technology in the beginning, but after a while we knew how everything works. Now, it takes us not more than one and a half hour per day to handle the complete sludge treatment on site”, said plant manager Johann Weihrich. The sludge treatment plant consists of a screw press and a solar sewage sludge drying system. Since years, solar sewage sludge drying has been a recognized technology for producing dry grains from a partly sticky sludge cake, reducing the sludge volume to approximately a quarter at the same time. Solar sludge drying represents an economically efficient method if the disposal price is approx. 80 € per ton or higher – and there are hardly any operating costs. The low operating costs include low energy consumption and a very good climate balance. On STP Freystadt, the installation of the solar sewage sludge drying plant resulted in a number of advantages: before the plant was built, contract dewatering companies emptied the sludge storage ponds at regular intervals. Emptying the ponds meant considerable efforts and operating expense: stirring the 8,000 m³ large sludge ponds for homogenisation, the load on the treatment stages due to the filtrate water, the effort necessary to regularly set up the mobile machines, and sludge removal and transport. Stationary dewatering eliminates peak loads caused by the filtrate water, ensures that the dry granulate is pourable and not sticky so that sludge transport is clean and easy. Moreover, sludge volumes are significantly reduced: only 180 t/a have to be removed from the plant. The example of STP Freystadt shows that a completely automated sludge treatment plant can be an economical solution even for smaller sites. HUBER SE could win the tender worked out by the engineering office Miller, Nuremberg. HUBER built the complete mechanical systems, had the structures erected and put the plant into operation – the complete plant from a single source, with all units perfectly attuned to each other. The thin sludge is homogenised in a supply tank of the ponds and pumped 350 m up to the sludge dewatering building where it is conditioned with the HUBER Inline Polymer Mixer IPM, a newly developed HUBER product. The mixer not only increases the dry residue at the outlet of the sludge dewatering system, it ensures also that outgassing in the sludge line is no problem for operation. The sludge is dewatered by the well-proven HUBER Screw Press Q-PRESS ® . The dewatered sludge cake is discharged into the HUBER Screw Conveyor Ro8 T that transports the sludge into the greenhouse. There, the HUBER Sludge Turner SOLSTICE ® takes over, breaking up and continuously turning over the sludge while transporting it through the greenhouse. A climate control system in the greenhouse ensures that optimal drying results are achieved. The system relates the electrical energy consumption of the ventilators to the drying efficiency to decide whether it is economical to activate the ventilators. The nearby sports field, playing ground and a club house for motorbike friends do not have to fear odour annoyance. The continuous process avoids odour peaks. Due to the intensive turn-over of the sludge bed by the sludge turner and backmixing of dry granulate into the wet sewage sludge, odour-producing processes are prevented. To backmix the sludge, the sludge turner with its tools takes in the granulate at the end of the drying way and transports it back to drop it at a defined point. The space on STP Freystadt is limited. The traffic areas required around the sludge treatment plant had to be kept as small as possible. As the SOLSTICE ® returns the material, feeding of wet sludge and removal of dry granulate can take place on the same side so that only one access to the drying hall needs to be built. After the plant operators’ decision to build the plant, they did not commission a contract dewaterer anymore. Due to the very good dewatering results and excellent performance of the solar dryer, it was however no problem to process within one year all the sludge that had accumulated over the year plus the freshly generated sludge. Plant manager Johann Weihrich is very satisfied with his new plant: ”It was the right decision. We have now a plant that works really well. Maintenance, process control, operation – the plant is designed to ensure that everything is smooth, easy and clean.”[...]