Source: Earth PD http://bit.ly/1JPJLLL Landfill PD http://bit.ly/1DGgRKm Landfill2 PD http://bit.ly/1CZDLOx Burning Trash PD http://bit.ly/1zSjECT Ocean Trash CC http://bit.ly/1DyPkdy Beach CC http://bit.ly/1F6MyxE Glass CC http://bit.ly/1I2TdOx Glass Machine CC http://bit.ly/1xj7Th5 Compost PD http://bit.ly/1zKsO4n Trash CC http://bit.ly/1zaamez
Hi, I'm Jensen Morgan. We're going to talk about some great concepts in environmental science. Today's topic is solid waste. So let's get started.
We're going to talk about human-generated waste, how it has changed, what its impacts are, and how it is managed. As population has grown and industrialization has expanded, human waste generation has increased substantially. Ecosystems function in a cyclic manner, meaning that all waste is recycled to become new resources.
Humans used to be a part of this process. But over time, our waste and what we do with it has changed. Human waste is the only waste on the planet that must be managed and stored, because we produce waste that does not recycle naturally. The result is that human waste is accumulating worldwide. Much of our waste is actually just unutilized resources-- energy and resources that could still be used and are becoming obsolete because they're stuck in our landfills and dumps instead of being recycled.
There are numerous sources of human waste. Household products such as furniture are thrown out because we want a change in style. Instead of being repurposed, it is taken to the landfill. Industry produces large quantities of waste, often as byproducts to manufacturing, like polluted water, stack emissions, and useful materials like wood scraps.
Treatment plants attempt to clean things like wastewater from cities, which creates by-products like sewage, sludge, and bio gas. Agriculture often produces large quantities of waste, both organic and non-organic in nature, such as cow manure or broken-down tractors. Mining, which provides lots of materials for things like modern-day electronics, produces massive quantities of waste, whether it be mined material that pollutes nearby waterways, or huge tailings that transform topography.
When talking about waste, it's important to point out that when talking about solid waste, it includes solid, liquid, and gaseous material. Wood scraps, waste water effluent, and smokestack emissions would all be considered solid waste. Waste can have a host of impacts. In order to store it, large plots of land must be set aside that could have been used for growing food or for other uses.
Off-gassing from waste in landfills, as well as other sources of waste, contributes to air pollution. Methane is a primary gas given off by decomposing landfills, which is a heavy contributor to climate change. Waste can also produce particulate matter and CO2 emissions. Waste can sometimes contaminate surface and groundwater when it seeps into water systems, which could lead to human health impacts. In general, waste can damage human and ecosystem health, interfering and damaging otherwise healthy populations.
There are different ways to manage waste to mitigate or buffer the negative impacts it can cause, though not all are created equal. In the past, waste was dealt with according to the whim and desire of those managing it. However, many such practices historically have led to disease. As a result, in many developed countries, there are now laws and regulations about how to manage and dispose of waste. In many developing countries, waste management laws are still lax or nonexistent.
We're going to cover six main strategies of managing waste. The first three are landfills, combustion, and ocean/lake dumping. Landfills take up otherwise usable land to store waste in compacted piles, contribute to climate change with methane and CO2 emissions, affect nearby communities with their smell, and can seep into water sources, contaminating them.
Combustion, or the burning of waste, may get rid of volume quicker than most management strategies. But it can release dangerous toxins, impacting human health and adding to air pollution issues. Ocean/lake dumping can severely impact aquatic system ecosystems, contaminate food chains, and, eventually, human health. This photo is of a section of the Pacific gyre, which is a state-sized floating pile of trash in the Pacific Ocean.
The second three methods are reuse, recycling, and composting. Reuse means taking an item and repurposing some or all of its parts, or refurbishing it for the same use. This photo here is of a glass bottle that was reused as a building material to bring natural light through this wall.
Recycling is breaking an item down into its core materials and making something completely new out of it. This photo is of a glass bottle recycling vending machine-- kind of cool, huh? These bottles will most likely be broken down and used in some other glass product. Compost is taking organic waste materials and facilitating their decomposition so they can be added as a soil amendment, ideally to grow more food.
There are other efforts made to assist the management of waste or discourage the creation of it entirely. In many US states, glass bottles have deposits paid on them which can be refunded if returned and properly recycled. Some municipalities charge residents for garbage produced, often priced by the can or bag, to discourage production of waste in the first place. Many products are labeled to indicate if they're recyclable, and some places will pay for recyclables like empty aluminum cans.
Now let's have a recap. Human waste has changed to be not naturally recyclable and increased in quantity over time. It has many different sources, such as household products and industrial waste. Solid waste includes solid, liquid, and gaseous material. The range of negative impacts are wide, and strategies to manage it are many, including things like ocean/lake dumping and recycling.
Well, that's all this time. I hope these concepts have been helpful. And I look forward to next time. Bye.