Mostrando entradas con la etiqueta ecological. Mostrar todas las entradas
Mostrando entradas con la etiqueta ecological. Mostrar todas las entradas

martes, 25 de enero de 2011

Wastes, Disposal and Strategies for Control

Type of Waste Disposal Strategy for control
Heavy Metals

Landfills. If not properly confined the leachate may pollute soil/ground water.

Mixed with cement and additive that encloses the sludge.

Nuclear Wastes

Depends on the type of waste:
-For low levels, material is compressed and buried in landfills
-For inter, level it may be solidified in concrete and buried
-For high level, it is placed in a container
Reuse (weapons, not cost-effective; hybrid reactors)

Very difficult. Confinement is needed wastes take thousands of years to decay. An option is to deplete highly radioactive materials

Organic Wastes

Pumping wastes into deep wells. The mulch is used as fertilizer.
Land —> provides biogas.

Biotech processes open / closed composting use microorganisms or worms. Aerobic / anaerobic bacteria break down organic matter.
Incinerators /pyrolysis

Plastic Wastes

Landfills
Incinerators.
Reuse/recycling

Efficient incineration provides useful thermal energy and control of the gases released.
Treatment
Conversion into fuels (Polymer Energy System)

Oils and Solvents

Small amount placed in containers and put in trash, landfills
Larger amounts, containers for recycling; oil –> biofuels.
Incinerators

Bioprocesses –> microorganisms break down molecules into simpler compounds.

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Method Description
Landfills Confinement of wastes into an area, covered by soil
Incineration Wastes are burned
Recycling Materials are changed and used in other products
Reuse A new use is find for materials or they are reused for the same purpose.
 

 

lunes, 22 de noviembre de 2010

Against the idealism of carrying capacity

A population model assumes that the use of resources is equal to all of the individuals. The think here is that we are talking about “individuals” not hard numbers. They have different needs and life conditions. That’s why we cannot take the entire population of the world as in uniform conditions in order to establish the carrying capacity (K)
The individual/population resource use is a dynamic principle. We also must we aware that resources vary with time and space. Some of this variations are given by:
  • MEDCs and LEDCs
  • Urban vs. rural
  • Young communities vs. older communities
However we need to manage carrying capacity to our advantage.
It might be trough pollution control
POLLUTION MANAGEMET
Natural income –> Human activity –> wastes –>  pollution
Pollution:the addition of a substance of agent to the environment by human activity at a rate grater that that at which it can be rendered harmless by the environment.
Major sources of pollution
  • Combustion
  • Domestic waste
  • Industrial waste
  • Agricultural waste
Pollution by noise, by heat.
Sources:
  • Point source
  • Non-point source
Detection and monitoring
  • Directly. measure with a particular variable to refer an specific pollution factor. (CO2 presence in the atmosphere)
  • Indirectly. Impact. uses a variable that depends on a specific factor. (e.g. acid rain: a wide range of possibilities to measure the impact; salinity on the atmosphere)
Pollution indicators
  • Biological Oxygen Demand (BOD): amount of dissolved oxygen required to break down the organic material in a water volume through anaerobic or aerobic activity
  • Indicator species (biotic index 1-10) through invertebrates
Three-level model of pollution management.
replace, regulate and restore
Waste management

lunes, 23 de agosto de 2010

The measuring Roll


The measurements information is used to value the state of things (good or wrong) and then act towards control the variables.

The methods for measuring biomass vary between ecosystems, biomes and type of organism.

It is important in the vegetation measurement, representing an indicator of productivity and of ecological and management processes in the vegetation.

Vegetation biomass measuring tell us what plant dominates a land by controlling the nutrients and water resources. Estimates of biomass and residual biomass also strongly influence the hydrologic properties of the site including infiltration, runoff, and erosion. Biomass of both grasses and woody plants constitute potential fuels that can be measured to assess the risk of wildfire.
Biomass can be directly measured with little training, although, it is time consuming.

The above MODIS Enhanced Vegetation Index (EVI) map above shows the density of plant growth over the entire globe. Very low values of EVI (white and brown areas) correspond to barren areas of rock, sand, or snow. Moderate values (light greens) represent shrub and grassland, while high values indicate temperate and tropical rainforests (dark greens). The MODIS EVI gives scientists a new tool for monitoring major fluctuations in vegetation and understanding how they affect, and are affected by, regional climate trends.

The biomass of a trophic level is likely to be proportional to the number of organisms and the energy found in each level. This could be graphically shown by the use of the ecological pyramid, which are graphical representations of the trophic structure of ecosystems: