lolwa meshaal report

The environment around us is represented by land, water, air, living creatures, microbes, plants and humans and all of them are linked together by a specific ecosystem. Since we are an integral part of the environment, we have to protect what surround us from any imbalance or abnormal phenomena which will cause the disruption in the ecosystem. However, the world is facing many problems in trying to protect the environment, one of those problem is the depletion of potable water or fresh water. Water pollution poses a considerable threat to the ecosystem and sustenance of life. The main reason of all environmental pollutions is the human activity. The human activities are disturbing the environmental balance which will lead to endanger the existence of the life in the earth. In our world, there are excessive amount of water pollution and wastewater which considered to be a challenge in the environmental protection sector. Environmental protection can be defined as the self-restriction to obey the government policies and procedures in order to conserve and protect all the natural resources. Self-restriction can be represented by having the intensity of the environmental awareness to preserve healthy and youthful level of the surrounding natural resources without affecting the standard limitation of polluting the environment. One of the major problems that we are facing today is water pollution. The reason behind taking this problem into a serious scenario is because the water is covering almost 71% of the earth surface and the oceanic water represent almost 96.5% of Earth’s water. It includes water bodies like ocean, rivers, lakes, ponds and streams. (Earn, M. 2005)

Today, water pollution has a significant effect on the environment this is because there almost 80% of the waste water is dumped back into the fresh water sources and pollute the environment which will lead to have unhealthy ecosystem because of the untreated water. All types of water pollution will be jeopardizing the human health, not only the human health, but the life of all the leaving creatures on our planet. First of all, water pollution happens when the unwanted or toxic materials usually microorganisms or harmful chemicals enters the water body sources. Water pollution can be classified into many types or categories, starting with the ground water (Earn, M. 2005)

Ground water is the water stored inside the crevices and porous space of an aquifer, or, the water stored beneath the earth surface. The original source of this water is rain falls which seeps into the earth cracks and crevices filling it with water. Ground water considered as one of the most important sources of fresh water, and in some areas, it is the only source of fresh water. The ground water pollution occurs when the pollutants are released into the ground and start violate the fresh water. When the ground water is contaminated it is nearly impossible to treat and becomes unusable instantly. As shown in figure below, It is very important to understand that when ground water is polluted or contaminated it spread far away from the original source seeps into other water sources such as lakes and streams which will result in contaminating of these areas. (Melissa Denchak 2018)

Surface water is covering almost about 71% of the earth, it consists of oceans, lakes, lagoons, rivers and any water source that occur on the earth surface. A recent study done by the U.S Environmental Protection Agency stated that nearly half of the surface water from fresh water sources in the U.S is polluted and unsuitable for the human activity it is unfit for drinking, fishing and even swimming which gives us an idea about how the waste is being bumped into waterways without any treatment. This pollution is manly caused by activities such as farm waste, fertilizer ran off, and random junk that is being dumped by individuals. Also, industrial and toxic waste from many factories and companies have a huge effect in causing surface water pollution. (Melissa Denchak 2018)

Oceans are the heart of the subwater streams in the life of our planet. Ocean pollution usually happens along the coast or deep inland. The mean cause of ocean pollution or also known as marine pollution is the contaminations that are being carried by rivers streams and lakes into the ocean. These contaminations may contain unwanted materials like; chemicals, nutrients, acids, and heavy metals that may travel by streams from cities into the ocean. Other causes of marine pollution are oil and toxic spells which may spread to cover a large area and damage the marine life. (Melissa Denchak 2018)

The point source water pollution is basically the type that has a specific and identified pollutant origin and it is released directly into the water from a single source. There are plenty of examples for this type of pollution drainage ditches, factories and power plants, oil refineries and any other factory that use the water in their processes and then dump the polluted water into a fresh water source. (Morgan 2019)

The non-point source water pollution is the type that has many discrete conveyances pollutant streams and they are released indirectly in the water and contaminate it. It is released in a large area as compared to the point source water pollution. There are various types of non-point source water pollution, starting with the runoff of a city remnants that carried with the air and water streams into any water body, it carries the oil leaks from cars, the garbage from the houses the chemical and toxic materials spells, all of these will be carried and dumped into the water over a large area. (Morgan 2019)

This type of water pollution is spread over a wide are and cannot be determined by a boundary or limitations because it transported from one point to other several far away points. The transboundary contaminated water can be from one country to another country. It is a result from many human activities, it could be from agriculture discharges, sewage streams, oil spill, industrial discharges. (Melissa Denchak 2018)

In this course, we are going to focus on the treatment of the wastewater methods specially the sewage and domestic wastewater, which is the process of removing unwanted materials from wastewater. So, first of all, what is the domestic and sewage wastewater?

Domestic or sewage waste is basically the water that has been disposed from the buildings, either houses, factories, or industries. It comes from toilet sinks or showers in houses, industrial processes in many industries. There are billions of people in our planet, therefore water treatment has to be a big priority. Sewage wastewater are treated in a water treatment plant and then can be used in other sectors like agriculture or dump the treated water in the sea. The water treatment plant can process the contaminated water by passing it into several processes, physical, chemical and biological processes and produce a safe and environmentally treated waste water that meet the specifications of the needed water. As shown in the figure below, in the conventional methods, in order to end up with this type of water, the domestic or sewage waste water have to go through many stages, these stages are going to be clarified in details. (Aditya Kumar, 2018)

As shown in figure 3, starting with the preliminary stage or screening stage which is the removal of the unwanted large and big items that might cause the damage to the important units in the facility like; pumps, valves. It is used before the primary treatment because it removes the sand and gravels and all the large impurities to prevent any problem from happening during the process.it used bar screens that shown in figure 4 below. This the stage where we can remove any waste object, cans, toys, bottles and rags. In this stage, the velocity is carefully monitor in channel called the grit channel or grit chamber (Figure 5). This is the channel that cause the sands, stones, grits and gravels to settle down in the bottom or the lower part of the channel, while letting the rest of the organic particles in the upper part of the water column. The grits are removed in the grit channel and being added to the large objects that comes from the bar screening and then send them to landfill or disposal place. (Pescod, M.B. 1992)

So, the screening is the point for removal of coarse solids such as rags, pieces of clothes and sticks. This protects the pumps, valve and other parts of the system from the risk of clogging. Then comminution comes, which involves shredding or breaking of larger solids to smaller size, maximum of 8mm. A comminutor is used for this purpose. After that the grit removal, grit refers to any inorganic solid like slit, pebbles and sand and organic substances such as bones, wood or seeds. They have to be removed to protect the pumps and pipes from wear and tear. Grit removal within the grit tanks can be done by careful control of the flow speed within the grit compartment. (Dr. Rjaendra Singh 2014)

This stage is focussing on the usage of tanks, or what we call it specifically sedimentation tanks. These tanks allow the incoming waste water to pass and move slowly through it. So, this could be a real advantage in this stage because if the coming wastewater is moving very fast the large materials are not going to sink down and the purification of water will be affected badly. Therefore, the proper purification depends on the rate of settling down the unwanted materials This stage is also called primary sedimentation clarifiers because it is large enough to separate the sludge down which are the solids in this stage, and letting the other materials to float on the top to be skimmed off, these material could be oil and grease. These tanks use scrapers in order to deal with the sludge and push it towards the base of the tank where there is hopper there, then it is discarded after any water removal and it is usually used in fertilizers. (Pescod, M.B. 1992)

The primary treatment stage includes skimming, sedimentation and neutralization.

a) Skimming step

This is done in the skimming tanks as shown in figure 6 below. Floating substances such as oil and grease are allowed to float on the water surface for easy hand removal or by mechanical force. The process is simplified for efficiency through aeration and vacuum flotation. (Dr. Rjaendra Singh 2014)

b) Sedimentation step

This is the removal of heavy solids using gravity. The sludge forming at the tank base is eliminated by vacuum suction or physical flocculation and chemical coagulation. The process of sedimentation is shown below. (Quach-Cu,2017)

c) Neutralization step

this is the control of acidity or alkalinity of the water. Limestone and sulphuric acid or CO2 gas are used in the acidity and alkalinity control respectively. (Scientific Expert 2020)

This stage is spotting the light on a removing the organic sediment and the suspended solids from the flowing wastewater by using biological treatment process. It comes after the primary stage and it consist of the removal of unwanted biodegradable dissolved and colliding the organic matter by the usage of aerobic biological treatment processes. It removes up to 90% of the human organic waste such as food waste. The aerobic biological treatment processes are mainly focusing on pumping the air which includes the presence of oxygen and it is performed by aerobic microorganisms that break down the organic matter in the wastewater, then end up having the organic end products and more microorganisms. The secondary treatment stage focuses on the activated sludge by aeration. The human and animals’ wastes are a major contaminant in the waste water, these types of waste will cause an extremely high level of biological organisms like bacteria and viruses. There are two types of microorganism’s bacteria, the bad bacteria and the good bacteria. So, in the current stage we have to increase the size of good bacteria and increase the size of the bad bacteria by letting it grow up in size in order to be collected and removed. And this happen by pumping the oxygen in the aeriation stage. (Guyer, P. J. (2011).

The process of coagulation and flocculation are shown in figure 7 below.

Coagulation-flocculation is the application of chemical substances for destabilising and increasing the particle sizes mixing and enhancing the sizes of flogs. The chemicals used are organic coagulants. Preferably aluminium salt or organic polymers or cationic flocculation substances or pH regulation reagents, like acids or alkalis. (Félicien Mazille 2019)

Before the tertiary treatment, water is ready for use in many sectors for example the agriculture. However, the tertiary stage is to increase the quality of water through removal of unnecessary contents. The steps of the tertiary treatment are explained below. (Sharma, N. (2019).

a) Removing of smaller floating solids: this process is enabled by the use of micro-strainers and sand filters.

b) Elimination of Bacteria: this is achieved by the retention of the effluents left after the secondary treatment ponds.

c) Elimination of Dissolved Inorganic chemicals: this is implemented by evaporation, various approaches, whichever is appropriate for the situations.

i. Evaporation: Evaporation applies only if the solids or solutions are reusable.

ii. Ion Exchange: Ionic exchange assists in getting deionized water to use in boilers under high pressures.

iii. Adsorption: Adsorption uses active carbon for elimination of fine amounts of organic contaminants carried by the water. This is specifically important for removing pesticides and carbonate insecticides.

iv. Reverse Osmosis: It is appropriate and operational in removing the dissolved solids in water via a semipermeable membrane.

v. Precipitation: this is the removal of solids that are dissolved in the water being treated, such as particulates, ions of heavy metal such as lead and mercury in form of precipitates. The metals are removed in their hydroxide forms.

The tertiary treatment is summarized in figure 10 below.

This report was covering the first three required tasks in the first week, so it was covering the introduction part by defining the environmental protection meaning and how it was linked to the self-restriction. So basically, environmental protection can be defined as the self-restriction to obey the government policies and procedures in order to conserve and protect all the natural resources. Self-restriction can be represented by having the intensity of the environmental awareness to preserve healthy and youthful level of the surrounding natural resources without affecting the standard limitation of polluting the environment. Also, it was covering the importance f environmental protection specifically for the water pollution problem and how water pollution is affecting our lives.in this report it is clear that treatment of water is a complicated procedure. From the preliminary stage to primary treatment, then to secondary and ultimately, the tertiary stage. However, the result of following all the steps involved is clean reusable water, safe for consumption and friendly to the ecosystem. It is also realized that there are different approaches of water, depending on the condition of the water. For a wastewater, the method used must follow all the four stages from preliminary treatment to tertiary treatment. Any breach or compromise to the process may be very detrimental to both human life and the environment.

I would like to reflect my weekly report starting with the summer online course, so this course was confused in the beginning since I didn’t have a group but then I joined my partners Majed and Mubarak, they are cooperating with me and they always help me so much in finding many sources. Also, regarding the topic, I know it look quite easy in the beginning but once I take a step and search about it, it seems that it is a bit advanced and not anyone can get all the needed information easily. But at the same time, it is an interesting topic because it is going deep into the environmental protection sector which and the problem that facing the environment depends first on the human behaviour before the chemical and biological processes, so once the people understand how difficult the process of treating the water, they will have self-restriction and behave more wisely towards the environment. The topic was easy once I started it but once I went deep into the chemical and biological conventional treatment methods, it seems that I have to spend more time in researching and thinking because not all the sources are having the same steps or the same process order. Regarding the references the most useful references was the one about the conventional waste water treatments methods, since I didn’t have any basic idea before searching, these references were very useful and helpful to me to understand the process and to have the right procedure about the conventional wastewater treatment. The most helpful sources were:

1. www.nrdc.org