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New £1 million Industrial Wastewater Treatment Plant

New £1 million Industrial Wastewater Treatment Plant

H+E are currently designing & building a Treatment Plant to handle wastewater from a process plant that uses a mixture of highly concentrated acids including Hydrofluoric and Nitric acids, and also contains a range of soluble metals.
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This particularly highly-sensitive application has demanded that all equipment within the overall plant be both designed and manufactured to an unusually high standard, with a target 40 year minimum design life. It also includes the supply of documentation to a very high standard.

 

The Solution: This involves neutralising the wastewater with calcium hydroxide in order to precipitate the fluoride as calcium fluoride. The pH of the incoming wastewater can be very low (less than 1) so the neutralisation is done in two separate steps, after which the solids produced are flocculated before being separated from the wastewater in one of our Tube Settlers, a highly efficient lamella clarifier design that has been a standard product used in literally hundreds of applications.

A typical pre-assembled chemical dosing systemFollowing settlement, the clarified wastewater flows into a TOVEKO continuous gravity sand filter, the purpose being to remove any final traces of fine solids that were not removed in the Tube Settler. Then the wastewater is cooled if necessary (it can sometimes be too warm to discharge directly to sewer), and has its quality monitored continuously before being mixed with various other non-toxic wastewater streams being discharged from the site. The final, mixed wastewater stream then has its quality monitored again before being discharged to foul sewer.

The sludge formed by the settling solids is transferred to a separate sludge holding tank, which automatically removes excess water that accumulates as the sludge settles further in the quiescent conditions provided, before it is finally pumped from the tank for final dewatering, producing a solid that can be disposed off-site.

The plant’s control system is unusually sophisticated, and features a far greater degree and depth of continuous control and monitoring than is normal for this type of wastewater in a more “standard” industrial environment.

 

img_0057Pre-assembly: The plant as a whole is being both manufactured and pre-assembled to a very high level and will be extensively inspected and Factory Tested prior to being delivered to site. Pre-assembly has been an integral part of our culture for a substantial time now, mainly because it enables us to control the quality of what we deliver and also because testing in our factories is so much more efficient than doing so on site.

You can find further information about H+E’s Tube Settlers and TOVEKO filters in the Downloads section.

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H+E UK Provides Process Water System for Pembroke Power Station

By Mike Hutt

The power station at Pembroke in South Wales is, at 2,160MW, the largest combined cycle gas turbine (CCGT) power plant in the UK. It was recently built for RWE npower. Following a number of previous contracts with both RWE and the main contractor, Hager + Elsässer was chosen to design and supply the process water system to feed the gas turbines.

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Addressing the operational cost challenges of zero-liquid discharge

Introduction

Zero-liquid discharge (ZLD) is a robust wastewater management solution that utilises a sequence of advanced treatment processes to minimise wastewater volumes, increase water recycling, and concentrate waste solids to the greatest extent possible. Numerous different treatment processes and combinations of technologies  can be utilised as part of a ZLD system, but a common denominator among the vast majority of available ZLD options includes a large thermal evaporation stage that is extremely energy-intensive, meaning high and often prohibitive operating costs. This challenge is driving the need for innovative ZLD solutions that offer effective and reliable treatment, and also overcome cost barriers to implementation, energy use, and operation. Read more