Monday, February 17, 2014
Procedures Water Treatment Plants Employ to Cleanse Waste Water
Have you ever thought about how much waste water, or water contaminated by elements such as human or industrial waste, we produce each day? Nobody managed to come up with a specific figure just yet, but observing water treatment plants should give you an idea. Several new methods of waste water treatment have sprung up over the years because of the amount of waste water treatment plants handle on a daily basis.
The increase in human population over the past decade also increased the amount of contaminants in our water supply. Human waste like feces or urine is commonly associated with water contamination, but other substances like paint, rubber residue, and industrial waste contribute to it as well. The main purpose of waste water treatment is to purify contaminated water for reuse or release back into the environment. It's a necessary process, especially since we've been using up our environment's supply of clean water at an alarming rate. Here are a few of the processes treatment facilities use to purify water.
Flocculation
Flocculation is a process that involves adding a clarifying agent to waste water, which solidifies the contaminants and makes it easier to remove them. A clay flocculant can easily separate dye, heavy metals, latex, oil, phosphates, paint, adhesives, and ink from waste water.
Filtration
Filtration is one of the earliest methods of removing solid contaminants from waste water. Today's filtration processes involve the use of a chamber filter press, which processes the water in batches. The process begins with clamping a stack of filtration plates together, and running the contaminated water through the plates. As the process continues, the solid contaminant accumulates into a "filter cake" within the plates. This filter cake is removed before the next batch of water is processed.
Dewatering Sludge
Sludge is the semi-solid material left behind by industrial waste water treatments. In a way, dewatering is the opposite of filtration and flocculation. Instead of removing solids from water, dewatering removes water from solids. While the primary purpose of removing water from sludge is to process that water for reuse, it also serves another purpose. Sludge, like any other waste material, needs to be disposed. If you own a factory, you'll find dumping waste often requires a lot of work and funds, especially if it's something as heavy as sludge. Removing water from sludge makes it lighter and easier to dispose.
Aeration
Aeration focuses on treating contaminated bodies of water. It increases the oxygen levels of waste water, which promotes the expulsion of toxic gases and breaks down other contaminants. There are three types of aeration:
- Subsurface aeration - This process infuses oxygen beneath the water's surface to improve its overall oxygen levels.
- Surface aeration - This type of aeration promotes oxygen exchange at the surface of the water, and releases contaminants like methane or carbon dioxide. It involves the use of fountains, floating surface aerators, and paddlewheel aerators to agitate the water's surface.
- Natural aeration - A combination of subsurface and surface aeration, natural aeration involves introducing plant life into the water. These plants restore oxygen to the water through the natural process of photosynthesis.