Wastewater Treatment for Aerospace Component Manufacture
A high quality wastewater treatment plant not only allows you to meet your environmental commitments, but also permits you to focus on what's important: your production!
If you manufacture metallic components for use in the aerospace and transport sector, the chances are that you will produce wastewater contaminated with a wide range of chemicals that needs to be purified before you are allowed to discharge it. H+E recently completed a treatment plant for a major international player in the Aerospace sector.
This plant was a replacement for a plant supplied to them in 1992 that had to be demolished to accommodate a factory expansion programme.In this particular case, wastewater arises from a number of different finishing lines scattered across the factory site. This means that wastewater is pumped to the treatment plant from a number of locations.
Much of the wastewater contains hexavalent chromium and is first collected in a Balancing Tank before being pumped to the chrome reduction stage of the plant. A second stream with no chromium is pumped directly to the pH neutralisation stage, where it joins the chromium stream after chrome reduction. A third stream containing tartaric acid is pumped to a separate neutralisation stage.
Due to the remote nature of the wastewater transfer stations, each is linked to the treatment plant so that, in the event of any treatment problem, pumping to the plant is stopped and water supplies to the process lines are also stopped, thus making the overall system safe.
Following chemical treatment, the wastewater flows through flocculation and settlement stages before overflowing to a TOVEKO continuous gravity sand filter that removes any final small solid particles that have escaped settlement. The treated wastewater then flows to a final discharge monitoring station where its pH, turbidity and flow rate are monitored before it is discharged to foul sewer. Collected sludge is held in separate tank before being dewatered in a filter press.
The most-used chemicals, sulphuric acid, sodium hydroxide and sodium bisulphite, are delivered to site in 1m3 IBCs, from where they are delivered directly to each point of use via an H+E-designed system that not only eliminates chemical handling but also ensures that each IBC is completely emptied before switching automatically to a second standby IBC. This is an important feature since the plant can operate 24/7 and personnel may not always be available to switch to a new IBC.
Treated Wastewater Quality
The most important quality limit is that for total chromium, simply because that is the most common toxic metal present. The limit specified for discharge is less than 1mg/l. H+E stated before the plant was built that the concentration actually expected after treatment would be less than 0.5mg/l, so the client set his own "alarm limit” at 0.4mg/l. Typical discharge from the plant contains no more than 0.2mg/l, clearly demonstrating the high quality of H+E’s design and indicating clearly why, after more than 20 years’ experience, the client chose to purchase another plant from H+E.
We are always very aware that such plants are not the reason you are in business, but a necessary consequence of what you do. We therefore aim to supply you with a highly efficient and simple-to-run plant that will reliably meet your goals.
Our plants are typically built in plastics as much as possible, and pre-assembled and tested in our factories. This not only improves quality, and therefore plant life, but also minimises overall cost.
Many years’ experience in designing and supplying a wide range of plants qualifies us to know what works and what doesn’t. This customer now has a plant that not only treats their wastewater reliably, to a high standard but also informs them remotely of any issues that may arise.
We can also remotely monitor the plant’s performance, and control the plant itself remotely if required.
Service and Technical Support are very important to our clients; the knowledge that when they have a problem, we are there for them!
Arguably, it was the provision of such service and support since 1992 that convinced this client that they could trust us to provide their new plant.
We not only train operators, maintenance engineers and managers how to operate the new plant but also provide additional training occasionally when personnel change.
Take Advantage of Our Experience
We always strive to offer each customer the technically and economically best solution, one that precisely meets your needs. Therefore to make use of all the know-how we have acquired in building more than 30,000 plants to do this.
Thus we make sure that we contribute to cost optimisation and the economic use of water resources and a significant reduction of emissions to the environment.