Introduction
What is Sustainable Development? Sustainable development is the ability to make the world a better place presently, without destroying the possibilities for future generations to come. In 2015 the United Nations (UN) formulated a plan with 17 sustainable development goals to better the lives of billions of people all over the world without leaving anyone behind by the year 2030. These goals can be expressed in a social progress index which includes: Basic human needs (food, water, shelter, and safety), Foundation of Wellbeing (Education, Information, Health, and Environment) and Opportunity (Rights, freedom of choice, and access to higher education). In this report, we are tasked with the role of investigating applications of engineering concepts that could aid in the achievement of these sustainable development goals.
All 17 goals are exclusively important in its own rights but, this report focuses on the challenges of goal 6 (Clean water and sanitation) because of the vital role it plays in the existence of life on earth.
Clean Water and Sanitation
Access to fresh clean drinking water is very important and invaluable to human health, growth of food and prevention of diseases. The water-related ecosystem has always provided natural processes and ecosystem services that sanitise and store clean water for human settlement. Yet, like other natural resources, our clean water is under threat. Research has shown that the demand for water has outpaced population growth, and half of the world’s population is already experiencing water scarcity at least one month a year. Rivers in Africa, East, and South Asia and the Latin Americas are more polluted than they were in the 1990s and, an estimate of 50% to 70% of the world’s wetland area has been lost over the last 100 years. Globally, there has been an increase from 61% to 71% of the proportion of the population using safely managed drinking water services between 2000 and 2017. This means there is still an estimate of 789 million people who lack basic drinking water services mostly in rural areas. In terms of sanitation, the global population using safely managed sanitation services has increased from 28% to 45% between the year 2000 to 2017. Some of the countries where growth was at its fastest were Latin Americas and the Caribbean, South East Asia and Sub-Shaan Africa. Despite the increase in both the sanitation and water services, there is still a huge amount of people who are unable to access these services. Therefore, it is up to engineers to develop innovative concepts that would improve and solve these problems.
One of the ideas that could have a tremendous impact on the water sanitation problems in the rural parts of countries is the introduction of Bio Sand Filters (BSF). The concept of bio-sand filters is nothing new to water purification processes, it is an adaptation for the traditional slow sand filter (SSF) which has been used in small communities for over 200 years. The idea behind this unique technology is that it uses a list natural to turn dirty, bacteria-filled and potentially deadly water into safe drinkable water. Water is poured through the top into a diffuser/filtration plate which removes all the large particles. It is an important part of the process as it slows the rate of the water flowing to the sand below where the filtration takes place. As the water begins to seep slowly through the top of the fine sand at a constant rate it creates a biological layer. This layer is an intensely active food chain that digests the diseases causing parasites and viruses in the water. As the water continues to seep through the fine sand it goes through another process called mechanical trapping which further traps organisms that might have pass through the biological process. The fine sand also carries an ecstatic charge that causes the organism to stick to the sand leading to another process called absorption. As the water travels further down the sand there is very little light or food and so the remaining organism dies naturally leaving the water free of contaminants. There is course sand set at the system to prevent the fine sand from being drawn in through the perforated pipes located at the bottom. The process is also based on gravity so as the water pushes down through the sand it creates pressure allowing the clean water to flow into the perforated pipes, through the tube and out inter the water storage to be accessed for drinking.
The Bio Sand Filter is a very inexpensive and very efficient system. On average a single bio-sand filter can range from US$12-70 to construct and install for a household of 10-15 people. It can be made with materials like concrete or plastic to increase the lifetime of the system and in the inside sand and gravel as agents for filtration. The efficiency of the system has been tested and it has proven to remover up to 100% of helminths (worms), 100% of protozoa, up to 98.5% of bacteria and 70-99% of viruses from the water by using this process. In terms of maintenance of the system, it is very easy to maintain, individuals using the system can be properly trained to remove the biohazard waste that would clog or decrease the flow rate over a period.
The Sustainably development target of access to adequate and equitable sanitation and hygiene for all, by ending open defecation and paying special attention to the need of women, kids and those in a vulnerable situation is an important and challenging target to achieve. To achieve this goal, it must first start with the idea of education, by this I mean starting within the school system and explaining to kids about the importance of hygiene and the results of bad hygiene. Another way of educating the public can be using mass communication for example radio ads, television, billboards, and public seminars.
Open defecation is a serious and major problem all over the world especially in rural areas and cities in High poverty. Open defecation can aid in polluting the environment causing serious health problems and illnesses to humans leading to death. It is said that about 892 million people which is about 12% of the world’s population still practice open dedication, and 678 million of that 892 million still practicing open defecation lives in just seven countries. A concept that could have a serious impact as a solution to this problem is the introduction of the Blue Diversion toilet and sanitation system. This system was developed to be installed independently from sewerage, water and the electrical grid for people in poverty areas. It is the next generation urine diversion dry toilet system envisioned by a research team in Switzerland called Eawag. The toilet has a flushing system integrated with a basin and small showerhead for personal cleaning within the unit. The used water is recovered in a self-cleaning ultra-filtration unit and is reused on site. The urine and excreta are separately collected under the system in a sealed container to be removed by service personnel when needed. After these containers are collected by the service personnel it is transported to a waste treatment facility to be produced into compost and urine-based fertiliser. The idea of the Blue diversion toile is more than just a toilet, it is part of a financially sustainable sanitation service that covers all aspects of the sanitation value chain. This idea will also provide proper sanitation to people living in a densely populated area in low-income countries.
Conclusion
The 17 Sustainable Development Goals targets the improvement of human life and securing a better future for all. It is evident that clean water and sanitation are invaluable to basic health, growth, and survival of humans. In this report, research has shown that even though there has been an increase in the water and sanitation services between the years 2000 to 2017 there is still a significant amount of people still without access to these basic important needs. In order to bridge this gap research was done on two engineering concepts that can assist in the continued growth of accessible water and sanitation services. The first concept speaks on the topic of water purification by using a slow filtration that proves that is very effective and reduces water contaminants by approximately 70 to 99%. The second is the concept of a dry toilet system that recycles water through a filtration system and separates urine and excreta allowing these waste products to be used for other benefits. Arguably there are many other ways to solve the issue of clean water and sanitation, but they all require a significant amount of money to develop. This Development Goal is also one of the most interconnected goals which aid in the education of water resource, economic growth, poetry reduction health and more. It is suggested that the media and nation’s government to take these Sustainable Development Goals extremely seriously as there are the bases of our existence a human being.
