Main Feature
We also see recycling of water in other areas, for example in the design and use of pipeline cleaning truck that re-use the cleaning water by filtering it through the tanks to take out the undesirables and recirculating the jetting/cleaning water. This minimises not only the time needed to ‘reload’ the tanks during cleaning operations, so making the operation very much more efficient, but also minimises the need to take treated water on-board more regularly. This also occurs in some countries where road sweeping waste is handled through a recycling process. The grits and litter and organics are separated at special plants that remove the detritus from the road sweepings collected and the resulting wastewater is re-used to reload the sweeper trucks for their next programme of work. The only water not recycled is that which remains in the moisture content of the solids removed by the separation process. So only a small amount of water has to be added to the truck to make up the full cleaning load. If in turn this can be linked to a rainwater collection system treated water need not be used at all.
Probably the largest potential source for recycled water however is that of the output from sewage plants. Clean water directives and other such legislation in various countries across the globe now require that water discharges from sewage plants are cleaned to a very high standard, largely to keep beaches clean for public use and reduce pollution problems at sea. What seems to be being missed here is the opportunity to recycle this water for consumption in other areas rather than simply putting back into the rivers and seas.
The term being used for this currently appears to be the potential for ‘toilet to tap’ recycling. There is the argument that the idea of reusing foul water discharge for this sort of recycling would not be to the taste of most consumers. However, given the clean water directives and the drive towards ever- improved discharge water standards beyond this, it is
whilst adding to the list of contaminants perhaps would be overkill by mentioning here.
RECYCLING METHODS
There are in many places active systems for the recycling of water, for example rainwater harvesting. The collection of rainwater is relatively simple with almost all houses and other building having roof guttering that directs collect rainfall off the building and into drains. The problem is that there is not much of this in place and new developments are as far as is known by this author, not yet required to plan-in such collection and recycling systems as part of the planning permission process.
There are however many options for using collected rainwater and they can be employed relatively easily if only to replace garden/field watering so as to negate the need to use expensive treated water from the supply mains. Gardeners have been doing this for decades if to centuries but only on a small individual scale with the odd water butt.
8 drain TRADER | April 2018 |
www.draintraderltd.com
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84
