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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).

Matter and energy

Vapor Phase Granular Activated Carbon

granullar activated charcoal

Vapor phase Granular Activated Charcoal (GAC) is a treatment technology that removes contaminants from air. Contaminated air is passed through one or more vessels containing GAC. Contaminants stay onto the surfaces of the activated carbon grains. The thermal processing of carbon, often from coconut shells, creates small porous particles with a large internal surface area. This processing activates the carbon. The activated carbon attracts and adsorbs organic molecules as well as certain metal and inorganic molecules. When the concentration of contaminants in the vapor exceeds a certain level, the carbon must be replaced.

 

Limitations and Concerns

  • Some degradation products such as vinyl chloride and smaller molecules are not sorbed well, and consequently must be monitored carefully.
  • All spent carbon eventually needs to be disposed in landfills or regenerated. There are few regeneration facilities.
  • The carbon used for some contaminants (g.,metals) can not be regenerated.
  • Relative humidity greater than 50% can reduce carbon capacity
  • Some compounds, such as ketones, may cause carbon bed fires because they release heat upon adsorption.

 

Applicability

This technology is used to treat off-gas contaminats with VOCs and some fuels.

Matter and energy

Utilization of Coconuts

Charcoal briquette

Indonesia is an important producer of coconuts in the world.  Despite the mass production of coconuts, application of the coconut is still generally limited to the fruit of copra, and coconut oil for home use. Other by-products such as coconut shells are usually treated as wastes and not fully utilized. Indeed, the weight of the shell reaches 12% of the weight of the coconuts. With this, we can see a big potential of such a large shell production for productive activities that can increase the value added.

One of the products made from coconut shell is the coconut charcoal briquettes. These are very green products because no trees are cut down and the waste that would otherwise be thrown away is now processed to be sustainable natural resources. Amazingly, compared to other conventional charcoal made by wood or coal, coconut charcoal briquettes have distinctive advantages, which make them more popular in the world market.

Among these, coconut charcoal burns hotter and longer that makes it especially perfect for slow grilling. There’s no added chemical on the charcoal, so everyone gets a clean burn. It is more like grilling with real wood rather than charcoal briquettes. The smell of the charcoal is rather neutral other than just having a grilling smoke smell with the foods.

Coconut charcoal briquettes are also reusable. When finished grilling the meal, the remaining charcoal can be used as a bottom or base for the next grill out. The coconut charcoal definitely has staying power.

Availability may be an issue in some areas, but it will never be the problem in Indonesia.

Life

Why is it important to protect drinking water?

Protect water

Contamination, the introduction of a pollutant or undesirable material into the air, soil, or water, has many negative and far-reaching effects. Thus it is important to protect drinking water from contamination for public health, economic, and environmental reasons.

Water is necessary to all living things. It makes up approximately 70% of the human body’s weight and plays a role in its functions, such as digestion and cooling.  Without clean drinking water, we could not survive.  If the drinking water is contaminated, many health risks can result: bacteria can result in illnesses such as hepatitis or cholera; a component of gasoline, benzene, is known to be a carcinogen; lead causes kidney, liver, and nerve damage as well as pregnancy risks.

Protecting drinking water also makes good environmental sense. In the past, people thought that if we buried chemicals in the ground they would disappear.  This is now a proven fallacy that has resulted in dire consequences for our environment.  Everything we put into the environment accumulates. Contamination can take years to clean up and not all ground water contamination can be treated successfully with current technology. This is why pollution prevention is crucial.

 

What is contamination?

Contamination is the introduction of a pollutant or undesirable material into air, soil, or water.  There are three types of contaminants: microorganisms, inorganic chemicals, and organic chemicals.  Microorganisms are living organisms such as bacteria, viruses, and Giardia.  Inorganic chemicals such as nitrate, arsenic and metals are another type of contaminant. Microorganisms and some inorganic chemicals are naturally occurring substances that taken out of drinking water through treatment at our local water systems.  Organic chemicals can be solvents, fuels, and pesticides.

Matter and energy

Activated Carbon Filter Guidelines

Activated carbon filter

AC filters have a limited lifetime. Eventually, the surface of the AC becomes filled with adsorbed pollutants, and no further treatment occurs. ‘’Break-through” takes place when pollutants break through the filter and emerge in the treated water. When it happens, contaminant concentrations in the treated water can possibly be even higher than those in the untreated water. The cartridge then needs to be replaced. Knowing when breakthrough will occur and when to replace the cartridge is thus a major problem with AC treatment.

Unfortunately, unless the pollutants are smelled or tasted, they can be unknowingly consumed. In most cases, break-through can be positively verified only by chemical testing. Frequent chemical testing is impractical and expensive. Some cartridges are sold with predictions about their longevity. But these are generally only crude estimates since they do not consider the characteristics of a specific water source.

The retailer from whom you purchase the treatment device can better estimate a filter’s useful lifetime based on water usage (flow rate) and pollutant concentrations, shown in the chemical analysis. To make the most accurate estimates, you should learn what these amounts are before purchasing the system. If pollutant concentrations increase over time, and without testing done to reveal the change, such estimates may not be very practical or useful.

AC filters can be excellent places for bacteria to grow. A filter saturated with organic contaminants, or one that has not been used for a long time, provides ideal conditions for bacterial growth. A saturated filter supplies the food source for the bacteria. It is still unclear whether bacteria growing on the carbon pose a health threat. Some manufacturers place silver in the AC to prevent bacterial growth. The effectiveness of the silver has not been independently verified. In addition, the silver may contaminate the drinking water.