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Waste Management
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Wastewater use :
As
freshwater becomes increasingly scarce due to population growth,
urbanization and, probably, climate change, the use of wastewater
in agriculture, aquaculture, and ground water recharge and
in other areas will increase. In some cases, wastewater is
the only water resource available to poor, subsistence-level
farming communities. Although there are benefits to using
wastewater in agriculture - including health benefits such
as better nutrition and food security for many households
- uncontrolled use of wastewater frequently is associated
with significant negative human health impacts. These health
impacts can be minimized when good management practices are
implemented.
Guidelines
for the safe use of wastewater in agriculture need to find
the right balance between maximizing public health benefits
and still allowing for the beneficial use of scarce resources.
Guidelines need to be adaptable to the local social, economic
and environmental conditions and should be co-implemented
with other health interventions such as hygiene promotion,
provision of adequate drinking water and sanitation, and other
primary health-care measures.
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| Solid
waste Management |
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Composting : |
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Composting is the decomposition of plant remains and other once-living
materials to make an earthy, dark, crumbly substance that is excellent
for adding to houseplants or enriching garden soil. It is the way
to recycle your yard and kitchen wastes, and is a critical step
in reducing the volume of garbage needlessly sent to landfills for
disposal. It's easy to learn how to compost. Composting can even
be done, cleanly and unobtrusively, indoors in apartment buildings
and condominiums!
Composting
is not a new idea. In the natural world, composting is what happens
as leaves pile up on the forest floor and begin to decay. Eventually,
the rotting leaves are returned to the soil, where living roots
can finish the recycling process by reclaiming the nutrients from
the decomposed leaves. Composting may be at the root of agriculture
as well. Some scientists have speculated that as early peoples dumped
food wastes in piles near their camps, the wastes rotted and were
terrific habitat for the seeds of any food plants that sprouted
there. Perhaps people began to recognize that dump heaps were good
places for food crops to grow, and began to put seeds there intentionally.
Today, the use
of composting to turn organic wastes into a valuable resource is
expanding rapidly in the United States and in other countries, as
landfill space becomes scarce and expensive, and as people become
more aware of the impacts they have on the environment. In ten years,
composting will probably be as commonplace as recycling aluminum
cans is today, both in the backyard and on an industrial scale.
Many countries have stated goals or legislative mandates to drastically
reduce the volume of waste being sent to landfills. Utilizing yard
and kitchen wastes (which make up about 30% of the waste stream
in the country is a big part of the plan to minimize waste overall.
You can contribute
to the 'composting revolution' by composting your own yard and kitchen
wastes at home. If you have a large yard, you might prefer the ease
of composting in a three-bin system out by the back fence. Apartment
and condominium residents can get into the act with indoor 'vermicomposting'
- using earthworms to recycle kitchen wastes (offices can even recycle
coffee grounds and tea bags with vermicomposting). Cities and towns
can promote composting through home composting education efforts
and the collection of yard wastes for large-scale composting. Whatever
your style of composting, there's plenty of room to get involved!
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COMPOSTING FUNDAMENTALS
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requires the following conditions: |
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1. Air :
The microbes that turn your yard and kitchen waste
into compost are "aerobes," which means that they need
air to live (and to do their work to make compost). Compost piles
should allow plenty of air into them. This is usually accomplished
by using some kind of "bulky" ingredients such as straw,
old weeds (without seeds!), etc. If a pile settles under its own
weight and excludes air, it can also be "turned" to get
more air into the pile. Turning is the process of dismantling a
pile and rebuilding it in a fluffed-up state - the fluffiness allows
air into the pile. Some people turn their piles several times as
the piles rot, to keep the pile as aerobic as possible.
2. Moisture :
The microbes need moisture to live (just like we
would die without water). Ideally, the pile should be "as wet
as a wrung-out sponge." At this ideal moisture level, the ingredients
are full of water, but there is still air getting into the pile.
And, the microscopic film of water on the surface of each particle
in the pile is an ideal medium through which the microbes can spread
as they do their work.A pile that is too wet (wetter than a wrung-out
sponge) will collapse under its own weight, excluding air and becoming
smelly. A pile that is too dry cannot support a healthy population
of microbes, and so the rate of decomposition is drastically reduced.
If a pile is too wet, turning it and/or adding drier ingredients
can help balance the amount of water in the pile. A pile that is
too dry should be turned, and water sprayed on the ingredients as
they are turned and rebuilt into
a new pile.
3. Warmth :
Active decomposition happens at average outdoor
summer temperatures. While higher pile temperatures will speed the
rate of decomposition, IT ISN'T TRUE THAT COMPOST PILES HAVE
TO BE HOT TO DECOMPOSE PROPERLY.
Only the largest piles will remain active through Colorado winters,
but even small piles will decompose during the warm season - as
long as they are moist, aerobic, etc. If you want to build a hot
pile, you'll need to have a cubic yard or more of material to build
the pile with all at once. You'll also need to make sure that you
have a good ingredient mix, proper moisture, etc. Not enough ingredients
to build a hot pile? No problem ... build a cold pile. There are
many advantages of hot compost piles, but there are advantages of
cold piles as well. Hot piles decompose more quickly, and may kill
weed seeds and other diseases. Cold piles, on the other hand are
often more convenient for backyard gardeners, who use an 'add ingredients
as you get them' approach.
4. The proper ingredient mixture :
In broad terms, there are two major kinds of food
that composting microbes need:
'Browns' are dry and dead plant materials such as straw, dry brown
weeds, autumn leaves, and wood chips or sawdust. These materials
are mostly made of chemicals that are just long chains of sugar
molecules linked together. As such, these items are a source of
energy for the compost microbes. Because they tend to be dry, browns
often need to be moistened before they are put into a compost system.
'Greens' are fresh (and often green) plant materials
such as green weeds from the garden, kitchen fruit and vegetable
scraps, green leaves, coffee grounds and tea bags, fresh horse manure,
etc. Compared to browns, greens have more nitrogen in them. Nitrogen
is a critical element in amino acids and proteins, and can be thought
of as a protein source for the billions of multiplying microbes.
A good mix of browns and greens is the best nutritional
balance for the microbes. Half-and-half of greens and browns, or
two parts browns to one part greens works pretty well. This mix
also helps out with the aeration and amount of water in the pile.
Browns, for instance, tend to be bulky and promote good aeration.
Greens, on the other hand, are typically high in moisture, and balance
out the dry nature of the browns.
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