Practice_of_Part_2_Theory_Chemical_Consideration_of_Pollutants.pdf

Practice of Part 2: Chemical Consideration of Pollutants 1- What are the meanings of hydrophilic and lipophilic? Hydrophilic means the materials that like to dissolve in water and water-like solvents. Lipophilic means the materials that like to dissolve in fatty and fatty-like solvents. 2-...

Practice of Part 2: Chemical Consideration of Pollutants 1- What are the meanings of hydrophilic and lipophilic? Hydrophilic means the materials that like to dissolve in water and water-like solvents. Lipophilic means the materials that like to dissolve in fatty and fatty-like solvents. 2- What is the definition of solubility? Solubility is the amount of solute needed to form a saturated solution for a given quantity of solvent at a given temperature to produce a saturated solution. grams of solute Solubility= 100 grams of solvent 3- Explain the following figure. This figure shows the solubility of most salts (ionic substances) increases with temperature, but exceptions exist too. For example, in this figure, the solubility of Ce2(SO4)3, against this rule, decreases with increasing the temperature. 4- What pollutants are hydrophilic? And what is their role in the environment? Hydrophilic pollutants are substances that readily dissolve in water. These pollutants include a variety of chemicals, such as salts, certain pesticides, and inorganic compounds. The solubility of hydrophilic pollutants allows them to move with water through various environmental sections, including surface water bodies, groundwater, and soil moisture. 1  5- What pollutants are lipophilic? Lipophilic pollutants include many organic compounds, such as certain pesticides, industrial chemicals, and polychlorinated biphenyls (PCBs). 6- What kind of materials are chelating agents? a- Chelating agents are organic compounds with multiple binding sites, known as ligands, that can form coordinate bonds with metal ions. b- Chelating agents are generally classified based on the target heavy metal – iron, copper, mercury, and lead being the major targets. c- Some chelating agents have a high degree of specificity for the target metal, while others chelate multiple agents. These ligands typically have functional groups such as hydroxyl (-OH), carboxyl (-COOH), or amine (-NH2) groups, which enable them to surround and bind to metal ions in a cyclic or ring-like structure. 7- What is the role of chelation in the aquatic systems and soils? Chelation enhances the solubility of metal ions in water. This increased solubility influences the transport and distribution of metals in aquatic systems and soils. 8- What is the application of chelating agents in water treatment? Chelating agents are used in water treatment processes to control metal concentrations and prevent the precipitation of metal ions which can lead to scaling or sedimentation. Ethylenediaminetetraacetic acid (EDTA) and citric acid are chelating agents commonly employed in water treatment. 9- What is the meaning of the half-life of a radioactive isotope? Half-life (symbol t½) is the time required for a quantity (of substance) to reduce to half of its initial value. Half-life is constant over the lifetime of an exponentially decaying quantity, and it is a characteristic unit for the exponential decay equation. 10- What is the definition of organometallic compounds and what are their sources? a- Organometallic compounds are compounds that contain at least one direct metal-carbon bond. b- These compounds often involve transition metals and are prevalent in natural and anthropogenic settings. 2 c- Certain industrial activities, such as metal catalyst usage in chemical manufacturing, can lead to the release of organometallic compounds into the environment. 11- What is the meaning of the phytoremediation? Some plants can accumulate and tolerate certain organometallic compounds, providing opportunities for phytoremediation to remove contaminants from soils. For example, by planting the sunflower we can reduce the amount of arsenic from the contaminated soil. 12- Explain the microbial remediation. Microorganisms can be engineered from natural environments to improve organometallic pollution through processes like bioremediation. Microbial bioremediation is recognized as a cost-effective, versatile, fast, and ecologically friendly method of removing toxins from the environment. 13- Explain the acid Mine Drainage (AMD). Acid Mine Drainage (AMD) arises from the exposure of sulfide minerals, typically found in rocks associated with coal and metal ore deposits, to air and water. This process results in the release of acidic and full of metal drainage, posing severe threats to aquatic ecosystems, soil, and human health. 14- What are the environmental Impacts of AMD? Only mention the names of these impacts. a- Water quality degradation b- Toxic metal contamination c- Stream and riverbed sedimentation d- Soil contamination 15- What are the reduction and improvement methods for AMD? Mention the name of these methods and explain one of them. Prevention: Implementing measures to prevent the formation of AMD is a key strategy. This includes minimizing exposure of sulfide minerals during mining operations, covering waste rock to limit contact with air and water, and applying neutralizing agents. Passive Treatment Systems: Constructed wetlands and ponds designed to promote natural chemical reactions that neutralize acidity and precipitate metals are known as passive treatment systems. These systems are often used to treat AMD. Active Treatment Systems: Active treatment involves the addition of chemical amendments to neutralize acidity and remove metals from water. Techniques include lime dosing, limestone channels, and various precipitation methods. Vegetative Covers: Planting vegetation on affected sites can help stabilize soils, reduce water runoff, and promote natural processes that neutralize acidity. 3 Isolation and Containment: In some cases, isolating and containing AMD-affected waters to prevent their spread is considered. This can involve the construction of barriers or diversions. 4