Filtering Polluted Water: Innovative Techniques For A Cleaner Future

Water pollution is a pressing issue that can have harmful consequences for both humans and the environment. Fortunately, there are several methods available to filter and purify polluted water, making it safe for consumption and reducing negative impacts on the ecosystem. One effective approach is the use of filtration systems, which can range from simple homemade filters to more advanced technologies such as reverse osmosis and carbon filtration. These systems work by removing impurities, such as dirt, disinfection byproducts, and even harmful microorganisms, from the water. In areas without access to electricity, gravity-driven filtration systems or natural processes like bioremediation can be employed. While it is important to address the sources of water pollution, these filtration methods play a crucial role in providing clean drinking water and mitigating the harmful effects of pollution.

Filtering water at home

Water filters can help improve the taste of your water, the safety of your water, or both. If your tap water does not contain harmful germs or chemicals, you may not need a filter. However, if you are concerned about the quality of your drinking water, there are several options available to filter water at home.

Types of Water Filters

There are many types of water filters available for purchase, including:

• Canister-style filters that attach directly to your kitchen faucet.
• Water filter pitchers, such as Brita or ZeroWater.
• Under-sink filters.
• Faucet-specific filters.
• Whole-house water filters, which filter water as it comes into your home.

Choosing a Water Filter

When choosing a water filter, it is important to consider your specific needs and goals. Different filters have different functions, so it is important to select one that is designed to address your particular concerns. For example, some filters are designed to improve the taste and smell of water, while others are designed to remove harmful chemicals or germs.

The pore size of a filter is an important factor to consider, as it determines the size of the substances that the filter can remove. Filters with smaller pore sizes can remove smaller substances. It is also important to understand that filters can remove beneficial chemicals, such as chlorine and fluoride, so you may not want to filter your water if it is already free from harmful substances.

DIY Water Filtering Methods

In addition to purchasing a water filter, there are several DIY methods that can be used to filter water at home or while travelling:

• Boiling water makes it safe to drink.
• Using purification or disinfection tablets or drops, such as sodium dichloroisocyanurate or tetraglycine hydroperiodide.
• Exposing water to ultraviolet (UV) sunlight to disinfect it by removing bacteria, viruses, and other microorganisms.
• Using activated charcoal, which can remove toxic compounds, smells, germs, fluoride, and heavy metals.
• Travel-size sediment filters, which come in the form of filtering straws, water bottles, squeezable pouch filters, or filtering water pitchers.
• Creating your own portable sediment filter by layering gravel, play sand, and activated carbon in a bucket drilled with a hole and fitted with plumbing.

Maintaining Your Water Filter

It is important to maintain your water filter according to the manufacturer's recommendations to ensure that it continues to work effectively and does not become a source of contamination. This includes regularly changing the filters and wearing gloves while doing so to avoid exposure to harmful substances.

Boiling water

Advantages of Boiling Water

• Kills harmful microorganisms such as E. coli, Salmonella, Giardia, and Cryptosporidium.
• Requires minimal equipment and can be done with readily available resources, making it a cost-effective solution.
• Provides a simple and immediate solution for emergency water purification.
• Boiling water can also make it softer and improve its taste.
• Boiling water retains minerals found in tap water, and drinking warm water may offer health benefits such as improved digestion and blood circulation.

Disadvantages of Boiling Water

• Boiling water does not remove chemical contaminants, heavy metals, or dissolved solids like lead and chlorine. In fact, boiling can concentrate certain contaminants, making them more dangerous.
• Boiling is a time-consuming process, especially for large quantities of water, and it can be expensive due to the energy required.
• Boiling water may alter the taste and odour of the water, and it does not guarantee the complete eradication of all pathogens, as some heat-resistant bacteria and spores can survive.
• Boiling also removes beneficial oxygen, vitamins, and micronutrients from the water.

Best Practices for Boiling Water

• If your tap water is cloudy, let it run through a clean cloth, paper towel, or coffee filter to remove sediments before boiling.
• Bring the water to a rolling boil for at least one minute, or three minutes at elevations above 6,500 feet.
• Allow the boiled water to cool naturally and store it in clean, covered containers.
• Boiled water can be kept in the refrigerator for up to three days or at room temperature for 24 hours.

In summary, boiling water is an effective method for purifying water in certain situations, especially when there is a risk of microbial contamination. However, it has limitations and should be combined with other filtration methods to ensure the removal of all contaminants.

Chemical disinfection

Chlorine

Chlorine is the most widely used method for disinfecting water supplies in the United States. Chlorination is effective at controlling the transmission of waterborne diseases such as typhoid and paratyphoid fevers, cholera, salmonellosis, and shigellosis.

The concentration of organisms in drinking water after effective chlorination may be exceedingly small, but sterilisation is neither attempted nor maintained in the distribution system.

The efficacy of chlorination depends on several factors, including:

• Its efficacy against waterborne pathogens (bacteria, viruses, protozoa, and helminths)
• The accuracy with which the process can be monitored and controlled
• Its ability to produce a residual that provides an added measure of protection against possible post-treatment contamination
• The aesthetic quality of the treated water
• The availability of the technology for adoption on the required scale

Ozone

Ozone is a powerful oxidant that reacts rapidly with most organic and inorganic compounds. It is generally used for disinfection in small institutions and private residences because it requires a dependable power supply and usually a second disinfectant to furnish a disinfecting residual in the system.

Chlorine dioxide

Chlorine dioxide is a strong oxidising disinfectant that has been used to treat drinking water supplies for more than 60 years. It is effective at controlling the transmission of waterborne diseases, but there is limited data on its mechanism of action.

Iodine

Iodine has been used as a disinfectant for drinking and swimming pool water, but mainly for emergency disinfection of field and emergency drinking water because of the costs and problems involved in applying the dosage.

Bromine

Bromine is a disinfectant that has been applied to water as liquid bromine, bromine chloride gas, or from a solid brominated ion exchange resin. It is more effective than chlorine in the presence of ammonia but reacts with ammonia to form bromamines, which are less effective oxidising and disinfecting agents.

Ferrates

Ferrates are strong oxidising agents that have been used to treat drinking water supplies. They are effective bactericides and virucides under the pH, temperature, and turbidity expected in water treatment, but there is limited information on their mechanism of action.

Hydrogen peroxide

Hydrogen peroxide is a strong oxidising agent that has been used for disinfection for more than a century. It is effective at controlling the transmission of waterborne diseases, but there is limited information on its mechanism of action.

Ionising radiation

Ionising radiation may be electromagnetic or particulate. It is effective at controlling the transmission of waterborne diseases but does not produce a residual, so another disinfectant must be added to maintain a disinfection capability in the distribution system.

Potassium permanganate

Potassium permanganate is a strong oxidising agent that has been used as a municipal water treatment chemical since 1913. It is effective at controlling the transmission of waterborne diseases, but there is limited information on its mechanism of action.

Silver

Silver and its compounds are weak, costly disinfectants that are unsuitable for use in municipal drinking water supplies. To achieve acceptable disinfection in a reasonable time would require concentrations exceeding the maximum contaminant level.

UV light purification

Ultraviolet (UV) light purification is a safe, effective, and chemical-free method of water treatment. It is particularly useful for neutralising microorganisms such as bacteria, viruses, and parasites, including harmful pathogens like Cryptosporidium, Giardia, and Legionella pneumophila.

UV water treatment systems emit germicidal UV light, which targets and penetrates the DNA of harmful microorganisms, rendering them unable to reproduce and cause illness. This process is contained within a specially designed reactor chamber, where contaminated water flows in and is exposed to UV-C light rays. The UV-C light damages the DNA and RNA of pathogens, effectively neutralising them and preventing them from reproducing.

However, UV light purification has some limitations. It is ineffective against non-biological contaminants such as pesticides, herbicides, volatile organic compounds (VOCs), chlorine, and heavy metals. Therefore, it is often combined with other filtration methods, such as carbon block, KDF, or reverse osmosis filters, to ensure comprehensive water purification.

Overall, UV light purification is an excellent choice for eliminating biological contamination from drinking water, especially in areas with boil water advisories or those seeking an eco-friendly alternative to chemical treatment.

Reducing plastic waste

Reduce Single-Use Plastics

The first step is to reduce your consumption of single-use plastics. These are items designed for one-time use and then disposal, such as plastic bags, plastic wrap, disposable cutlery, straws, and coffee cup lids. Instead, opt for reusable alternatives like cloth bags, containers, and metal or bamboo straws. Making your own meals instead of ordering takeout also helps reduce plastic waste from packaging.

Boycott Bottled Water

Close to 20 billion plastic bottles are thrown away each year. A simple way to reduce this waste is to carry a reusable water bottle and refill it with tap water or filtered water. This is also a safer and more economical choice.

Avoid Microbeads

Microbeads are tiny plastic scrubbers found in beauty products like facial scrubs, toothpaste, and body washes. Due to their small size, they can pass through water treatment plants and end up in the oceans, where marine animals mistake them for food. Choose natural exfoliants like oatmeal or salt instead.

Purchase Second-Hand Items

Consider buying second-hand plastic items, such as toys, containers, and other products. This reduces the demand for new plastic products and gives pre-owned items a new lease of life. You can also sell or donate your unwanted plastic items that are still in good condition.

Recycle and Reuse Plastics

Recycling plastic is crucial, but it's even better to reuse plastic products whenever possible. Repair and maintain plastic items to extend their lifespan and avoid early replacement. When recycling, check the symbols on plastic containers to identify the type of plastic and whether it's accepted by your local recycling program.

Support Sustainable Businesses

As a consumer, you can support businesses that are actively reducing plastic waste. Choose companies that minimize plastic packaging and offer recyclable or compostable alternatives. Your purchasing decisions can encourage more sustainable practices across industries.

Advocate for Change

Use your voice to advocate for policies that reduce plastic waste. Support initiatives like bag taxes or bans, and urge manufacturers to adopt more eco-friendly packaging. Contact your local representatives and express your support for regulations that address plastic pollution.

Frequently asked questions