Clean Water from a Biosand Filter

The Need For Clean Water

The water that comes out of the taps in our homes goes through a few steps of preparation before it is consumed, or used for washing dishes, food, and even ourselves.

Why? Because fresh water contains pathogens (viruses, parasites, and bacteria), toxins (such as arsenic and mercury), or just any suspended particulates that discolor or cloud the water (also known as turbidity).

In the West, most cities and towns have municipal water treatment plants that clean up the water to make it safe for usage and consumption. This is something we take for granted and don’t have to worry about: it is extremely rare for those systems to fail, thus putting us at risk at being sick, or even dying.

For several areas in Africa, such systems do not exist. People living in these poorer regions of the world are at risk from consuming unclean fresh water, yet they cook with it, wash their clothes with it, and when thirsty drink it.

To build and operate water treatment plants in the Third World would be too expensive a solution. The materials required to assemble them are scarce as well. What is required is a low-cost water purification solution that uses materials that are plentiful and easy to find.

Enter the biosand filter, or BSF.

What are BSFs?

BSFs are the modern-day version of the slow sand filter systems, which were first introduced in 1804 by a bleachery owner named John Gibb in Paisley, Scotland. Gibb invented a water filter made of of sand and charcoal that could strain pollution from the River Cart.

The function of the BSF is to help extract pathogens and toxins from freshwater. It also removes foul odours and makes the water clear in appearance. BSFs use a series of physical and biological processes that clump, trap, and strain foreign material out of the water.

BSFs are made of commonly available parts that are easy to assemble, resulting in a filtration system that is easy to operate.


How Do BSFs work?

BSFs consist of a physical housing that take in the dirty water, a sieve or diffuser is located at the top. The sand filters and extracts unwanted pathogens and toxins. Through the use of gravity the clean water enters into a container. The housing can be made of any material that does not rust or would accidentally contaminate the filtration process, such as plastic or concrete. Concrete is the most commonly used material for reasons of durability and the weight of which makes the BSF difficult to steal.

A lid secures the opening at the top of the BSF to prevent any germs, insects, or small animals from contaminating the filter process.

Water first passes through a diffuser. The diffuser evenly distributes the water over the biofilm and filtration sand, both of which work together in the water filtration process (this is why it’s called a “biosand filter”). This is necessary so both the sand and the biofilm are not disturbed, which would affect the ability of the BSF to filter the water.

What is biofilm? Well, the best example would be the film that forms over your teeth that could lead to cavities and gingivitis if you do not brush. It’s a suspension consisting of micro-organisms floating in a shallow layer of water over the filtration sand and takes a few weeks to form naturally. The “helpful” organisms in the biofilm compete for oxygen and food with the “harmful” organisms in the water, resulting in the death of the latter due to predation and starvation.

The next layer is the filtration sand, which strains the remaining pathogens and suspended particulate and any undissolved toxins from the water. The filtration sand is fine in texture and specifically selected to perform the filtration process.

The separation gravel supports the filtration sand but does not do any actual filtration. Its purpose is to prevent any filtration sand from leaving the BSF. The water moves through this layer much more slowly than the filtration sand layer.

The drainage gravel at the bottom of the unit is the final layer the water passes through. It supports the separation gravel, while preventing the separation gravel from exiting the BSF.

The design of the BSF allows the water to flow down through the aforementioned filtration layers, and later rising upwards in a channel to exit through an outlet spout. The now clean filtered water is captured in a water container designed to prevent recontamination and later used for cooking, drinking, washing, and bathing.


The Benefits Of BSFs

BSFs are commonly used in developing countries in the South American, Asian, and African continents, and can be found in operation at the community level in households and schools. BSFs can be used alone, or as part of an existing decontamination process in either a pre- or post-process support role.

BSFs ensure the production of clean water that can be used for drinking, food preparation, personal hygiene and sanitation.

According to the Centre For Affordable Water and Sanitation Technology (CAWST), BSFs remove over 95% of bacteria and between 80 and 90% of viruses if the filter is properly installed and used. Any microorganisms that manage to escape the BSF will be insufficient enough in number to make a healthy adult sick.

BSFs have been proven to reduce the amount of waterborne disease. Studies conducted by the University of North Carolina and the University of Nevada in the Dominican Republic and Cambodia reported a drop of diarrheal diseases by 47% in all age groups.

While there are few reports available that report the effectiveness of BSFs in the removal of heavy metals in freshwater, a study conducted in South Africa revealed BSFs removed 64% of iron.

BSFs have a high rate of clean water production (30 litres or more per hour).

Because the materials needed to build a BSF are commonly available and very affordable, nearly any family can own one regardless of income level. They require very little time to understand how to operate.

BSFs offer a business opportunity for those who wish to earn an income supplying assembled BSF units, or the materials required to assemble them. A household version of the BSF was proposed by David Manz in the 1990s at the University of Calgary, Canada.


How Education Improves African Women’s Lives (Part 2)

The knowledge required for being informed about birth control methods also comes into play when African women are at particular risk of contracting sexually transmitted diseases such as AIDS. One study has revealed that girls who go to school are three times less likely to be infected with the HIV virus. Part of the problem is where young girls were getting their information about AIDS from. They believed that AIDS was a curse to punish the wicked, and also that anyone who looked healthy could not be HIV-positive. Ensuring women attend and stay in school is key to removing such dangerous myths and arming young girls with the understanding that will steer them clear from both early pregnancies and life-threatening sexually transmitted illnesses.

The high infant mortality rate and the prevalence of sexually transmitted diseases, both of which have a root from young girls not remaining in school, places further pressure on countries that already have strained social safety nets. Hospitals face chronic shortages in staff and resources needed to care for pregnant women and for those stricken with AIDs. As a result, governments spend more on taking care of a population that is unable to contribute rather than work on roads, water, and power systems that are in need of modernization and repair.

In light of these pressing social issues listed above, having more educated girls makes perfect sense. On average, girls who receive more education will spend on average 90% on her family.

African women also need a positive and healthy understanding of what being successful in society really means. In the past, young girls in Africa engaged in sexual relationships with older men for financial gain or finding a good husband that will take care of her and her family. As a result, it was impossible for young girls to believe in the idea that they could be independent enough to take care of themselves, rather than being dependent on men in order to survive. Sometimes this relationship evolves further into getting caught up in the commercial sex industry, tragically coerced by family members in order to pay for the bills and get food. In the end, they become little more than a service, paid by those who can afford it.

Keeping girls in school ensures two things. First, it gives them the education that will serve as tools later in life to not need to choose the path of marriage for financial convenience but instead become more self sufficient by earning a better income. It also gives them a level of confidence and a healthier view of themselves where they are not substandard to men as things but equal to them as persons.

The final point to address is that once the effort is made to keep young girls in the education system in order to improve their lives and the families they care for, little additional effort is required down the road for the following generations. Women who learn the value of education today will teach their children what they know and send their girls to school, and in turn these girls too will continue that practice. The domino effect from this transference of knowledge will wash over all the societies of African nations like a tidal wave, except in this case it will bring constructive positive development instead of the heart-rending news we read about in the newspapers and watch on TV.


How Education Improves African Women’s Lives (Part 1)

If, as Nelson Mandela once said, that education is the most powerful weapon which you can use to change the world, the women of Africa are armed with little better then butter knives in a region of the world that desperately needs a social Renaissance.

More than half a school classroom in Africa are girls, yet most of them will stop going to school by the secondary school age, to be married and have children of their own — often as young as 13 years of age. The problem is these girls, having been taken out of the education system, are incapable of reading a simple sentence, let alone the ingredients on the back of a food product or the instructions of a medicine package. They do not understand that they and their children need regular immunization to prevent sickness. Africa contributes 20% of the world’s births but also 40% of maternal deaths.

Because young girls do not learn about the legal system of their home country or how to socialize, they are at risk of being drawn into the world of organized crime syndicates and drug trafficking. They may even be at risk of being victims of a crime, particularly sexually related crimes. For example, South Africa has one of the highest record of rape in the world, a country where police response is generally too slow and unreliable. In addition, a study published in the American Journal of Public Health revealed that more than 400,000 women are raped in the Democratic Republic of Congo every year.

While the above statistics are alarming, the facts about keeping African girls longer in school bring more positive outlooks that greatly benefit the society they live in. Even teaching the basics — reading, writing and arithmetic — not only improves their chances of entering the workforce, they will also earn more — up to 25% more in fact. The longer they remain in the education system, and progress to post-secondary education, the more likely their income will continue to rise.

Keeping African girls in school means they are less likely to marry and have children at such a young age. This gives them more choices from just being a mother. They become participants, even agents of change, in many aspects of society. Successful African women who are able to run their own business will become employers and creating more jobs. The revenue generated from these businesses in the form of taxes will help improve failing infrastructure systems — water, electricity, and roads — that still exist in many countries in the African continent. Some women may become more involved in governmental and judicial policies that shape the future of the country they live in, as well as the African continent as a whole.

Mothers who remain longer in the education system are able to afford food to feed their children and medicines to keep them from being sick. They are also able to read what is nutritionally important to the development of a growing developing child and properly understand the dosage of medicines required. Of particular important is the ability to understand the importance of birth control and the various options available to keep their family size manageable.


Education in sub-Saharan Africa

The prosperity of a country depends in part on the productivity of its citizens. Education plays an important part in ensuring both productivity and prosperity, since the more educated the population, the higher the standard of living through higher earned wages.

What does this say about a region of the world where roughly half the population does not receive any education at all?  Sub-Saharan Africa has only two out of thirty-five countries at gender parity, where boys and girls are in school and receiving an adequate amount of education. As stated in the 2013 World Population Data Sheet released by the Population Reference Bureau, Africa’s population is expected to rise from 1.1 billion to to 2.4 billion by 2050. According to Wendy Baldwin, CEO of the PRB, nearly all of that growth will be from sub-Saharan Africa, noted to be the region’s poorest.

Imagine that. A significant population growth over the next 35 years, yet nearly half that increase in the population will not have the needed education to help raise the standard of living in that area of the world.

There are many factors that prevent girls from receiving the same amount of education as boys. One of which is cultural, where girls are forced into child marriages and the household obligations forced on them due to social classification based on gender, with the governments of sub-Saharan countries unable if not unwilling to do anything about it. Another is the issue of civil infrastructure, where schools are unable to take on the additional influx of female students due to inadequate sewage, water and electrical systems currently in place. There’s also the shortage of insufficient female teachers to promote a gender-sensitive environment to consider as well.

Gender-parity in education is the key to raising the quality of living in this region. Girls who attend school are less likely to contract diseases such as HIV and AIDS and as a result are less of a drain on already strained medical reserves. Instead of being forced into child marriages or exploited through child labour, more girls with access to equal education will enter the workforce and earn a higher wage standard, which in turn translates into increase revenue for the government to pay for existing and expand on future social services. The resulting increased earning power also allow girls to grow up to become empowered women with a greater influence in social, economic and political aspects in their country. They also become better consumers which benefits industries and businesses in that region.

This in turn leads to a more stable geopolitical situation, since citizens tend to protest and riot less when their basic needs are addressed through equal access to education and the opportunities it brings.

The benefits of gender parity does not stop at the current generation either. A domino effect of equal economic opportunity will be produced for future generations as well.

The investment of time, effort, and money to ensure gender parity a wise investment in the economic and social growth and stability in sub-Saharan Africa. What is required is the removal of barriers created from cultural norms and gender prejudices that have existed in these countries for many generations.