The fluffy stuff in wastewater
Once had a Garmin GPS named Fluffy....
- Sat up in the clouds somewhere, always knew where to take me, and issued precise instructions. But this is not about her.
The abuse of water is not a new topic. We flush just about anything down the loo, the kitchen and the shower. Even old engine oil and the dead pet hamster is discarded down the drain. In my time I have seen babies and blankets, children's shoes, wallets, medicine and old electrical cables, and a little sewage stuff, often. A few years back, we maintained a small pump-station that served a famous chicken outlet in Durban CBD, and regularly had to unblock pumps. The main culprit was . . . . ladies underwear - panties to be specific. Anyone wearing knickers (I don't, by the way), will know they are made from extremely tenacious, highly durable material, such that one just cannot easily destroy. The material is a combination of nylon, rayon, polyester, and Spandex (or silk Spandex).
The solution would have been to install grinder, or cutter pumps, that would, hopefully, slice up the material into 'fluff' and this would then get pumped up the line into the main municipal sewerage system. Problem solved? No! While the problem has passed the chicken outlet, the material is still there, but in thousands of much smaller particles, almost like fluff. Fluff cannot be screened out, or separated at the Waste Water Treatment Works (WWTW) . This fine material chokes up the valves, the venturi, the bio-media, sluices and smaller orifices. These particles neither sink nor swim, but drift around. Sludge and bacteria are likely to attach to them, particularly in activated sludge (municipal) systems. However bacteria cannot eat much from this "food" since it is hardly biodegradable. Should the ladies undergarment arrive at the WWTW intact, it would certainly have been screened out, at the very beginning of the process.
These grinders blades are pretty tough, allowing very neat slicing of softer material, provided the blades are sharp. Sand, always present in wastewater streams, will quickly blunten the edges, the pump will clog up and jam. And these pumps are not cheap. Personally, I would have selected different pumps, that did have clearances to allow for a higher solid passage.
Now, you probably asking if I allowed my Fluffy to wear panties. I forbid it, so she stopped working.
And I replaced her.
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