IFAT 2018

••• 16••• Innovationen “Bait, hook and destroy” Energy-saving tech removes contaminants from wastewater A polymer mat developed at Rice University in Houstin, Texas, has the ability to fish biolog- ically harmful contaminants from water through a strategy known as “bait, hook and destroy”. Tests with wastewater showed the mat can efficiently remove targeted pollutants, in this case a pair of biologically harmful en- docrine disruptors, using a frac- tion of the energy required by other technology. The technique can also be used to treat drinking water. The mat was developed by scientists with the Rice-led Nano- technology-Enabled Water Treat- ment (NEWT) Center. The mat depends on the ability of a common material, titanium di- oxide, to capture pollutants and, upon exposure to light, degrade them through oxidation into harmless byproducts. Titanium dioxide is already used in some wastewater treatment systems. It is usually turned into a slurry, combined with wastewater and exposed to ultraviolet light to destroy contaminants. The slurry must then be filtered from the water. The NEWT mat simplifies the pro- cess. The mat is made of spun polyvinyl fibres. The researchers made it highly porous by add- ing small plastic beads that were later dissolved with chemicals. The pores offer plenty of surface area for titanium oxide particles to inhabit and await their prey. The mat’s hydrophobic (water- avoiding) fibres naturally attract hydrophobic contaminants like the endocrine disruptors used in the tests. Once bound to the mat, exposure to light activates the photocatalytic titanium dioxide, which produces reactive oxygen species (ROS) that destroy the contaminants. NEWT researchers said their mat can be cleaned and reused, scaled to any size, and its chemistry can be tuned for vari- ous pollutants. “Current photocatalytic treat- ment suffers from two limita- tions,” said Rice environmental engineer and NEWT Center Direc- tor Pedro Alvarez. One is ineffi- ciency because the oxidants pro- duced are scavenged by things that are much more abundant than the target pollutant, so they don’t destroy the pollutant. “Second, it costs a lot of money to retain and separate slurry pho- tocatalysts and prevent them from leaking into the treated wa- ter,” he said. In some cases, the energy cost of filtering that slurry is more than what’s needed to power the UV lights. “We solved both limitations by immobilizing the catalyst to make it very easy to reuse and retain,” Alvarez said. “We don’t allow it to leach out of the mat and impact the water.” Alvarez said the po- rous polymer mat plays an impor- tant role because it attracts the target pollutants. “That’s the bait and hook,” he said. “Then the pho- tocatalyst destroys the pollutant by producing hydroxyl radicals.” Specks of titanium dioxide adhere to polyvinyl fibres in a mat capture and destroy pollutants from wastewater or drinking water. Photo: Rice University / NEWT Anzeige 831 eWON routers enable remote monitoring at Thames Water sites Installing eWON industrial Ether- net routers – which provide secure remote control and diagnostics – Thames Water is able to remotely monitor and control critical assets located at its water pumping sta- tions across the UK. Jim Grandison, Workstream Lead for the SCADA Delivery Program at Thames Water comments: “We are using eWON Ethernet routers primarily to achieve secure, re- mote communications to critical monitoring and control equipment, installed in our waste water pump- ing stations and sewage treatment works. This project is part of our investment programme between 2010 and 2015 to improve our networks, and the systems we use to run them, with the main aim of providing a better service for our customers.” As Jim Grandison puts it: “The problem with dial-up is that the data you are looking at is histori- cal, perhaps as much as 24 hours out of date. In order to provide up to date, relevant customer service data and to be able to respond more quickly to any op- erational issues, we need to have access to information about our assets in real time and to be able to respond to that information, without having to send engineers to site, to check what the actual problem is.” From historical to proactive as- set management “The important thing”, says Gran- dison, “is that our customers re- quire clean, drinkable water, deliv- ered in a short time with minimal interruptions. In water pumping stations, we have traditionally mon- itored only the outcome of a failure after it has occurred, but not why that asset failed. With the eWON devices, we can immediately gain access to diagnostic information. This real-time remote monitoring approach supports our ongoing five-year Asset Management Pro- gramme, which will see our busi- ness change from ‘historical’ to ‘proactive’ management of assets.” “The objective is to be able to mo- bilise the right people with the right tools, in order to go to site to rectify any problems. Previously, we would have to send an engineer or team of engineers to site to investigate the problem first, then decide who and what tools to send in next.” The role of the eWON VPN router is to provide secure, resilient, re- mote-access through the Internet, to the PLC/RTU devices on site, using a combination of both Eth- ernet and Mobile connection. Reliable, secure connectivity Dave Hammond, Communica- tions Product Manager at M.A.C Solutions comments: “ Using their in-built library of PLC protocols, each eWON can monitor process data securely in real-time from the site PLC/RTU. In addition, each eWON continually feeds the site PLC/RTU with real-time data, concerning the health and status of the comms links on the site.” The objective is to ensure reliable, resilient remote communications, through the eWON to the PLC/ RTU on each site, from a master control station at “Thames HQ”. These links need to be used for multiple purposes simultaneous- ly, such as to gather data, modify process parameters, backup site devices and also perform device maintenance. VPN connections “Rather like spokes on a bicycle wheel, each eWON device at the end of a spoke is connected to a VPN concentrator at the centre. Across these secure VPN links, eWON devices will pass live real time data to and from site assets, such as pressures, flows, tempera- tures, status of equipment and so on”, explains Hammond. “With the ability to switch be- tween Ethernet and 3G/4G mo- dems, the eWON gives us a real advantage, as it guarantees con- nectivity and visibility of real time information from our most impor- tant assets.” HMS Industrial Networks. Stand A6.308 Projectpresentations&highlightsat IFAT Flexy 205 - IIoT Gateway & Remote Access Router