Literature Review
Introduction
Coagulation and flocculation processes are essential in a number of diverse disciplines including biochemistry, rubber manufacturing and in water and wastewater treatment (Bratby, 2006). These processes are typically used in destabilizing, agglomerating and subsequent removal of particles. Coagulation is a physico-chemical process which neutralizes the colloidal particles in water by a chemical called coagulant. The neutralization forces the colloidal particles to join together to form small aggregates called flocs which are easily filtered from the water.
The widely used coagulants in water treatment are metal salts including aluminium sulphate , aluminium chloride , polyaluminium chloride , ferric sulphate and ferric chloride (Saunders and Saunders, 1991). The primary mechanisms by which coagulant can remove both organic and inorganic contaminants from water include colloid destabilization, precipitation and co-precipitation (Langelier and Ludwig, 1949; Randtke, 1988; Saunders and Saunders, 1991). Mer and Healy(1963) deplored the indiscriminate use of the terms coagulation and flocculation which is found to represent synonymous concepts. It was proposed that the term coagulation be based on colloidal destabilization where colloidal particles
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The recycle sludge process has advantages over the conventional process because it produces a much denser sludge due to the “seeding” effect of the precipitates in the recycled sludge (Streeter et al., 1971). Seeding is commonly used in the metallurgical fields to allow precipitation products to grow and become larger in size. The nature of the precipitate formed in the presence of the seed crystals is known to be influenced to a large extent by the seed crystal size, seed crystal amounts and agitation rate (Streeter et al.,
When these components are mixed with the water, this causes the tiny particles of soil to stick together or coagulate. These particles are now bigger and heavier, they are known as flocs which makes it easier to remove by settings of filtration.
Goal: Total Words in this Document: Title: 1. EC and Me: Why Electrocoagulation Matters 2. Water Treatment 101: What You Need to Know 3. What to do with Construction Wash Water?
Chemical interactions can often lead to the production of environmentally unsafe byproducts. If the byproducts have no use, they are disposed as waste. Waste disposal companies make profit by collecting and disposing large amounts of these unused byproducts. These companies often concentrate the byproduct solutions so that they are easier to dispose of. One particular chemical waste disposal company wishes to utilize these concentrated byproduct solutions to create potentially useful solids (Bauer 45). It was the lab group’s goal to design procedures for creating
The first stage involves the removal of solid and liquid particles through filtration. Sydney Water mainly uses ferric chloride to prevent the recurrence of murky water. They also use small amounts of long chain polymers (polyelectrolyte) as a secondary coagulant. It is then followed by the inactivation of microorganisms; to which all monitored filtering plants uses a strong oxidant for disinfection (in Sydney Water, chlorine is used). The last stage involves the addition of fluoride to the water to fulfil the requirements of the Fluoridation of Public Water Supplies Act 1957. This, along with the added lime and carbon dioxide, reduces the corrosivity of
clotting in vessels. This makes the person more vulnerable if when cut for the blood flow to cease in
The objective of this lab was to separate a mixture that consisted of elements and compounds. There are seven ways to separate a mixture which included paper chromatography, filtration, evaporation, simple distillation, fractional distillation, magnetism, and separating funnel. The only methods used in this lab were filtration, evaporation, magnetism, and separating funnel. The method of magnetism was used when the magnet was moved under the mixture to separate the iron. The process of filtration involved the use of a filter paper placed in a filter funnel. The funnel was placed in a beaker and the mixture of water, sand, and sodium chloride was poured into the funnel. The liquid part drained through the filter paper into the beaker, leaving the solid sand particles trapped on the filter. After the water and sodium chloride were in a beaker, the process of evaporation was used. The compound was boiled on a hot plate, which led to the water
Instead of drawing small particles together, pool floc drags them down to the bottom, where it needs to be vacuumed out. Pool floc works quickly but you’ll lose a significant amount of water in the process.
Another common remediation technique is stabilization or solidification which aims to alter the contaminants into a less soluble or mobile form (Wuana and Okieimen, 2011; Mulligan, Yong, and Gibbs, 2001; United States Environmental Protection Agency, 1991). In both methods water and a site-specific chemical solution is mixed into the soil to either alter its physical - make it less soluble - or chemical - reduce mobility - properties to make it less likely that the contaminants will move into other locations or be inhaled (Wuana and Okieimen, 2011; Mulligan, Yong, and Gibbs, 2001). Chemical treatment can also fall under the umbrella term of stabilization. Chemical treatment is add chemical solutions to the soil to detoxify the soil and can be used as a pre-treatment for other techniques such as solidification (Wuana and Okieimen, 2011; Mulligan, Yong, and Gibbs, 2001). These techniques are typically preferred due to lower costs but other physical elements of the soil, such as boulders, can make mixing the soil difficult and the process can volatilize and release volatile compounds (Mulligan, Yong, and Gibbs, 2001; United States Environmental Protection Agency, 1991). Mobility of contaminants can also be reduced by using the technique of vitrification through the process of heating up the soil (Wuana and Okieimen, 2011; United States Environmental Protection Agency, 1991). This method results
Thrombin is a naturally occurring protein that is present in the blood of humans and animals. The main function of thrombin is as an intermediate step during hemostasis, which slows bleeding by forming blood clots. Thrombin acts as an enzyme during an injury, converting fibrinogen to fibrin, which then causes blood clots to form. Due to its properties, thrombin’s application to the medical field includes topical surgery in the case of minor injuries as well as various other medical procedures such as neurosurgical operations. Apart from applications in the medical field, thrombin also plays significant roles by directly interacting with endothelial cells throughout the body.
Today's media has displayed countless ways they show media bias. Many channels have depicted a different side to one story and base information on a political party in which the channel supports. Each news source has one goal, and that is to state what will make the chosen party to have a good platform for the public to see. In the series of events that have occurred recently one can see how different news sources have pushed for what each channel believes is the main point needed to be crossed and have shared beliefs in either a liberal or conservative way.
To ensure that the Animas River returns to its original state and the drainage from the Gold King Mine is cleaned up, we believe that a high density sludge process should be used. We believe the most effective high density sludge process is the health steele process. This process works by first mixing the sludge with lime in a tank so that the water can return to it’s original ph. Once the water reaches a safe ph for drinking, it reaches the lime reactor where air is added to ensure the water doesn’t change when exposed to air. Once the water leaves the lime reactor it is transported to the floc tank, where the remaining contaminated particles are removed from the drinking water. The final step is when the water reaches the clarifier and is sent back out to the river, as a healthy drinking water.
Linguistic Stereotype Threat Effects on Immigrant and First-Generation American Students Large body of psychological research accumulated evidence for the stereotype threat, a negative belief on a group which adversely affects group’s performance in various fields. It is critical to examine stereotype threat as it might account for unutilized skills, impaired performance and reduced chances of success for the members of stereotyped groups. Furthermore, stereotype threat might become a self-fulfilling prophecy and strengthen existing stereotypes by yielding predicted outcomes. It is worth noting that impaired performance of the stereotyped groups reduces human resources and is unfavorable both for the groups and the society as a whole. The purpose
Managing today’s public organization is much more complicated than it was ten to twenty years ago. The external environment is changing faster than organizations can move to meet the changing demands. The ideology behind the bureaucracy or public organization is much like that of our United States Constitution, designed for stability and endurance. For this reason, the public organization has operated internally under strict guidelines while resisting change. These ideas have passed through generations of bureaucrats as, "the way things are done." In this manner, organizations hire specialists to perform routine procedures to provide some good, product, or service to the community. Employees are
The basis of this experiment was to test how different contaminates effect ground water when absorbed. The results were surprising as that I felt any additives would immediately change the entire break up and color of the water. What was most surprising to me was that filtering vinegar through ground water it came out relatively clean. I also believed that when filtered all of the water would have large traces of dirt, but that was not the case with the vinegar. This means that there are still viable ways to filter and purify water.
The second step of water treatment process is aeration. At the aerator, raw water is mixed with air. The aeration process helps to provide oxygen to the raw water which is needed for the oxidation process of dissolved iron and manganese in order for it to precipitate and therefore enables its removal through filtration (SAJ Holdings Sdn Bhd., n.d.). Wormleaton and Tsang (2000) stated that for water treatment process and also natural streams, it is essential to maintain a high amount of dissolved oxygen. Aeration also provides the escape of dissolved gases, such as carbon dioxide and hydrogen sulphide to reduce the corrosiveness of water, thus controls the tastes and odors of the water (Shun, 2007). Groundwater with high dissolved carbon dioxide levels or high concentrations of iron and manganese commonly require aeration as well as water drawn from reservoirs that is low in dissolved oxygen.