Browse Month by January 2016
Matter and energy

Centralized vs. Point of Use Treatment

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Drinking water treatment can be accomplished either in centralized water treatment facilities or at individual homes or businesses.

In large cities, water treatment facilities treat large volumes of water intended for residential, business, and industrial uses. While the technologies may be fairly standard, such a system may have a host of infrastructure, such as filters, chemical storage, pumps, piping, valves, electrical equipment, and instrumentation. Initial cost is typically high. They may also require water source development, construction of infrastructure, and adoption of a system to distribute the water to consumers. In most developing countries, these systems may be financially out of reach for smaller or poorer communities.

Smaller communities can reduce costs by using pre-engineered “package plants.” Most package plants designed to provide water filtration are typically not equipped for disinfection, corrosion control, or adsorption of organic contaminants by granular activated carbon.

Where community treatment plants are not available or are not trustworthy, water treatment becomes a more individual choice. Point-of-use and point-of-entry water treatment systems are widely used in individual homes and businesses. In poorer areas, where there are significant deficiencies in financial resources and technical skills, point-of-use and point-of-entry may be the only treatment options. Point-of-use systems are typically installed where water is used for drinking and cooking, such as on the kitchen faucet. Point-of-entry systems, in contrast, are installed where water enters a building and treat all water to be used for any purpose at that location. Systems exist that can treat a number of contaminants including primarily aesthetic concerns (e.g., color and odor).

Matter and energy

Breathe Easy: Guide To Improve Indoor Air Quality

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We tend to think of air pollution as something outside — smog, ozone, or haze hanging in the air, especially in summer. But the truth is, the air indoors can be more polluted than the air outside. The air inside your home may be polluted by lead, formaldehyde, radon, or even volatile chemicals from fragrances used in conventional cleaners. Children, people with asthma, and the elderly may be especially sensitive to indoor pollutants.
To improve indoor air quality, follow these simple steps:
1. Keep your home fresh
Chemicals and allergens can accumulate in household dust for decades. By using a vacuum with a HEPA filter you can reduce concentrations of lead in your home. You can also get rid of other toxins as well as allergens like pollen, pet dander, and dust mites. A HEPA filter ensures that dust and dirt won’t get blown back out in the exhaust. In high traffic areas, vacuum the same spot several times. Don’t forget walls and carpet edges, where dust accumulates. For best results, vacuum two or more times each week and wash out your filter regularly.

2. Keep a healthy level of humidity
Dust mites and mold love moisture. Keeping humidity around 30%-50% helps keep them and other allergens under control. A dehumidifier (and air conditioner during summer months) helps reduce moisture in indoor air and effectively controls allergens, Lang says. An air conditioner also reduces indoor pollen count — another plus for allergy-sufferers.

3. Make your home a no-smoking zone
Perhaps the most important aspect of indoor air pollution is secondhand cigarette smoke. Cigarette smoke contains more than 4,000 chemicals. For the smoker, this addiction causes cancer, breathing problems, heart attacks, and stroke. Secondhand smoke will also increase a child’s risk of developing ear and respiratory infections, asthma, cancer, and sudden infant death syndrome (SIDS).