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Veolia helps UK dairy reduce its impact on the environment
NEWS FOCUS
Veolia helps UK dairy reduce its impact on the environment Edited by Simon Atkinson This brief article describes the way in which Veolia Water Technologies is working with one of the UK’s largest dairy operations to reduce its impact on the environment, and pioneer sustainable development, with the aim of establishing a zero carbon facility. The dairy’s facility management company approached Veolia Water Technologies to help it develop a wastewater treatment system, in line with its ambitious plan for its £150-million dairy, and implement innovative technology to reduce the net carbon dioxide contribution from power supplied to the plant. The production of one litre of milk uses the equivalent volume of water and generates vast amounts of low- and high-strength wastewater and solid waste, as well as making considerable power demands. A zero carbon operation is undoubtedly a challenging target. The approach required needed to take into consideration all of these factors, and also ensure that the effluent discharge adhered to specifications set by the local water authority.
Recycling and reuse The priority was to look at recycling and reusing water to reduce environmental and financial costs. Low strength and grey water were cleaned via a reverse osmosis plant and the recovered water returned to the dairy for clean-in-place before reuse. Treatment of medium- and high-strength wastewater is a more complex process, which Veolia overcame by designing, supplying and commissioning a waste-to-energy facility in a three-phase process, using its technology to produce effluent suitable for sewer discharge – simultaneously generating biogas and fertiliser, and reducing waste disposal costs. Wastewater from milk production is treated using an anaerobic process, resulting in clean water, biogas and biomass byproducts. The biogas is used either as fuel on-site for the plant’s combined heat and power system, or to supply heat energy to the milk produc8
Membrane Technology
tion process. The nutrient-rich biomass created in the reactor is allowed to thicken, and is harvested and used by local farmers as a substitute for land fertiliser.
Membrane bioreactor Phase one involved the installation of a Memthane anaerobic membrane bioreactor (AnMBR), taking advantage of patented, technology developed by Biothane – part of the Veolia group – to provide cost-effective treatment of high-strength wastewater within a small 75-m2 footprint.
‘A zero carbon operation is undoubtedly a challenging target.’ Sitting within a system of components – including an equalisation tank, ultrafiltration (UF) membrane banks and polishing units – the reactor significantly reduces operation costs compared with conventional technologies. It is designed to handle 500 m3 of wastewater every day, removing 5.5 tonnes of chemical oxygen demand (COD) – a measure of the oxygen required to decompose organic matter and oxidise the inorganic chemicals in water. The UF membranes ensure that the effluent is effectively free from suspended solids and is suitable for sewer discharge, within stringent regulated consent limits. The treatment system was monitored during the first year of phase one operation, and the collated data were studied to gain information about the wastewater characteristics and increased volume demands. Veolia worked with the dairy company to meet requirements for the phase two design,
including a second reactor to build in resilience and robustness, and ensure continuity of milk production even in the event of reactor failure. In addition, the plant was upgraded to handle 800 m3 of wastewater per day, containing 8.7 tonnes of COD, and aerobic stages – which depend on Veolia’s ANITA Mox and Dissolved Air Flotation (DAF) technology – were incorporated at the end of the process to reduce levels of ammonia and phosphate in the sewer discharge. The final phase focused on the solid waste digestion plant, which generates energy by treating out-of-date returns from the company’s extensive customer base. Veolia developed the interface between the digestion plant and the Memthane reactor, enabling biogas and water to be transported to the plant. Once there, the water aids in the digestion process and the biogas is returned to the grid as gas or electricity.
Zero carbon goal The plant was completed in 2015, and has clearly demonstrated that a combination of good planning and advanced process technologies can go a long way towards achieving the company’s zero carbon goal. Veolia’s wastewater treatment solution has reduced COD in the wastewater by more than 99%, producing between 0.6 Nm3 and 0.7 Nm3 of biogas per kilogram of COD removed. The dairy is successfully managing varying volumes and strengths of wastewater, and has reduced its reliance on external power, whilst continuing to develop new products at the site. (This news focus is based on press material issued by Veolia Water Technologies.) For further information, visit: www.veoliawatertechnologies.co.uk/products/ memthane
January 2018
Veolia helps UK dairy reduce its impact on the environment Edited by Simon Atkinson This brief article describes the way in which Veolia Water Technologies is working with one of the UK’s largest dairy operations to reduce its impact on the environment, and pioneer sustainable development, with the aim of establishing a zero carbon facility. The dairy’s facility management company approached Veolia Water Technologies to help it develop a wastewater treatment system, in line with its ambitious plan for its £150-million dairy, and implement innovative technology to reduce the net carbon dioxide contribution from power supplied to the plant. The production of one litre of milk uses the equivalent volume of water and generates vast amounts of low- and high-strength wastewater and solid waste, as well as making considerable power demands. A zero carbon operation is undoubtedly a challenging target. The approach required needed to take into consideration all of these factors, and also ensure that the effluent discharge adhered to specifications set by the local water authority.
Recycling and reuse The priority was to look at recycling and reusing water to reduce environmental and financial costs. Low strength and grey water were cleaned via a reverse osmosis plant and the recovered water returned to the dairy for clean-in-place before reuse. Treatment of medium- and high-strength wastewater is a more complex process, which Veolia overcame by designing, supplying and commissioning a waste-to-energy facility in a three-phase process, using its technology to produce effluent suitable for sewer discharge – simultaneously generating biogas and fertiliser, and reducing waste disposal costs. Wastewater from milk production is treated using an anaerobic process, resulting in clean water, biogas and biomass byproducts. The biogas is used either as fuel on-site for the plant’s combined heat and power system, or to supply heat energy to the milk produc8
Membrane Technology
tion process. The nutrient-rich biomass created in the reactor is allowed to thicken, and is harvested and used by local farmers as a substitute for land fertiliser.
Membrane bioreactor Phase one involved the installation of a Memthane anaerobic membrane bioreactor (AnMBR), taking advantage of patented, technology developed by Biothane – part of the Veolia group – to provide cost-effective treatment of high-strength wastewater within a small 75-m2 footprint.
‘A zero carbon operation is undoubtedly a challenging target.’ Sitting within a system of components – including an equalisation tank, ultrafiltration (UF) membrane banks and polishing units – the reactor significantly reduces operation costs compared with conventional technologies. It is designed to handle 500 m3 of wastewater every day, removing 5.5 tonnes of chemical oxygen demand (COD) – a measure of the oxygen required to decompose organic matter and oxidise the inorganic chemicals in water. The UF membranes ensure that the effluent is effectively free from suspended solids and is suitable for sewer discharge, within stringent regulated consent limits. The treatment system was monitored during the first year of phase one operation, and the collated data were studied to gain information about the wastewater characteristics and increased volume demands. Veolia worked with the dairy company to meet requirements for the phase two design,
including a second reactor to build in resilience and robustness, and ensure continuity of milk production even in the event of reactor failure. In addition, the plant was upgraded to handle 800 m3 of wastewater per day, containing 8.7 tonnes of COD, and aerobic stages – which depend on Veolia’s ANITA Mox and Dissolved Air Flotation (DAF) technology – were incorporated at the end of the process to reduce levels of ammonia and phosphate in the sewer discharge. The final phase focused on the solid waste digestion plant, which generates energy by treating out-of-date returns from the company’s extensive customer base. Veolia developed the interface between the digestion plant and the Memthane reactor, enabling biogas and water to be transported to the plant. Once there, the water aids in the digestion process and the biogas is returned to the grid as gas or electricity.
Zero carbon goal The plant was completed in 2015, and has clearly demonstrated that a combination of good planning and advanced process technologies can go a long way towards achieving the company’s zero carbon goal. Veolia’s wastewater treatment solution has reduced COD in the wastewater by more than 99%, producing between 0.6 Nm3 and 0.7 Nm3 of biogas per kilogram of COD removed. The dairy is successfully managing varying volumes and strengths of wastewater, and has reduced its reliance on external power, whilst continuing to develop new products at the site. (This news focus is based on press material issued by Veolia Water Technologies.) For further information, visit: www.veoliawatertechnologies.co.uk/products/ memthane
January 2018