This is a list of present-day cities by the time period over which they have been continuously inhabited.
The age claims listed are generally disputed and may indeed be obsolete. Differences in opinion can result from different definitions of “city” as well as “continuously inhabited” and historical evidence is often disputed.
Several cities listed here (Balkh, Byblos, Aleppo, Damascus, and Jericho) each popularly claim to be “the oldest city in the world”.
Marlyn Suarez completed AB Literature in the University of Santo Tomas, Manila, Philippines. Started her blog Kintal, meaning impressions in 2013. There she shares her abstract arts and poems.
On her blog she posts her own art works as well as her family members’ works along with her reflections from the past and current thoughts. Most of the words were taken from deep understanding about life, society and the conversations shared between her and her husband and sometimes with the kids all in the form of poetry.
You can visit her blog here www.kintal.wordpress.com for more of her works. We are glad to share a few of her works here.
“Remediate” means to solve a problem, and “bio-remediate” means to use biological organisms to solve an environmental problem such as contaminated soil or groundwater. Microorganisms used to perform the function of bioremediation are known as bioremediators.
In a non-polluted environment, bacteria, fungi, protists, and other microorganisms are constantly at work breaking down organic matter. What would occur if an organic pollutant such as oil contaminated this environment? Some of the microorganisms would die, while others capable of eating the organic pollution would survive. Bioremediation works by providing these pollution-eating organisms with fertilizer, oxygen, and other conditions that encourage their rapid growth. These organisms would then be able to break down the organic pollutant at a correspondingly faster rate. In fact, bioremediation is often used to help clean up oil spills.
Bioremediation of a contaminated site typically works in one of two ways. In the case described above, ways are found to enhance the growth of whatever pollution-eating microbes might already be living at the contaminated site. In the second, less common case, specialized microbes are added to degrade the contaminants.
Bioremediation provides a good cleanup strategy for some types of pollution, but as you might expect, it will not work for all. For example, bioremediation may not provide a feasible strategy at sites with high concentrations of chemicals that are toxic to most microorganisms. These chemicals include metals such as cadmium or lead, and salts such as sodium chloride.
Nonetheless, bioremediation provides a technique for cleaning up pollution by enhancing the same biodegradation processes that occur in nature. Depending on the site and its contaminants, bioremediation may be safer and less expensive than alternative solutions such as incineration or landfilling of the contaminated materials. It also has the advantage of treating the contamination in place so that large quantities of soil, sediment or water do not have to be dug up or pumped out of the ground for treatment.
Limitations :
Not all contaminants, however, are easily treated by bioremediation using microorganisms. For example, heavy metals such as cadmium and lead are not readily absorbed or captured by microorganisms. A recent experiment however suggests that fish bones have some success absorbing lead from contaminated soil. Bone char has been shown to bioremediate small amounts of Cadmium Copper and Zinc. The assimilation of metals such as mercury into the food chain may worsen matters. Phytoremediation is useful in these circumstances because natural plants or transgenic plants are able to bioaccumulate these toxins in their above-ground parts, which are then harvested for removal. The heavy metals in the harvested biomass may be further concentrated by incineration or even recycled for industrial use.
The elimination of a wide range of pollutants and wastes from the environment requires increasing our understanding of the relative importance of different pathways and regulatory networks to carbon flux in particular environments and for particular compounds, and they will certainly accelerate the development of bioremediation technologies and biotransformation processes.
