Photochemical Formation of Hydroxyl Radical from Effluent Organic Matter - the Role of Composition – Lab Report Example

The paper "Photochemical Formation of Hydroxyl Radical from Effluent Organic Matter - the Role of Composition" is a good example of a lab report on chemistry. Hydroxyl radical (HO is aneutral state of hydroxide ion (HO-). The hydroxyl radicals form an important part in radical chemistry because they are highly active and short-lived. They are mostly formed by the decomposition of hydroperoxides or reaction of water and the excited atomic oxygen. The formed radicals are also important in radiation chemistry, as it leads to the formation of oxygen and hydrogen peroxide that enhance corrosions in coolant systems. This is subject to radioactive environments. However, the paper aims at illustrating the roles played by composition processes in the photochemical formations of hydroxyl radicals from effluent organic matter. 

The hydroxyl radical is mostly referred to as troposphere’s detergent because it reacts with various pollutants, which acts as the initial step for its removal. This characteristic has also given its important role in eliminating greenhouse gases such as ozone and methane. In addition, the reaction rate of hydroxyl radical determines the number of pollutants lasting in the atmosphere, especially if they are not rained out or do not undergo photolysis (Goldstein and Galbally 1514–1521).

Moreover, the formation of hydroxyl radical (HO•) form effluent organic matter (EfOM) through photochemical depends on the chemical properties available in the heterogeneous mixture in it (Silva et al. 250-256). In order to demonstrate such notions, this study uses two EfOM samples that are collected treatments plants of wastewater as illustrated in the graph below as WWTP A and WWTP B respectively. The samples were fractionated by both hydrophobicity (either bulk or non-humic) and apparent molecular weight (AMW). For each subfraction, subsequent measurements were taken for the apparent quantum yield for hydroxyl radical formation (ΦHO•). The measurements were also taken for the maximum fluorescence quantum yield (ΦF).

After considering the independent pathways of hydrogen peroxide, the resulted formation rates of HO• for the bulk waters were 4.8 × 10–10 and 9.6 × 10–11 M s–1 for WWTP A and WWTP B, respectively. Furthermore, the decrease of AMW materials causes the increment of ΦHO• values in the AMW fractions.
For the first sample, WWTP A, it was noted that the ΦHO• increased from 2.54 × 10–4 of bulky water to 6.29 × 10–4 for the <1 kDa fraction. On the other hand, the value of ΦHO• in the second sample, WWTP B increased from 6.50 × 10–5 for bulk water to 3.45 × 10–4 for the <1 kDa fraction.
In the case of fluorescence, the values of ΦF were noted to range from 2.37 × 10–4 of bulk water to 3.48 × 10–4 (<1 kDa fraction) for WWTP A. The values of the second sample, WWTP B ranged from 3.19 × 10–4 for bulk water to 5.75 × 10–4 (<1 kDa fraction).
Moreover, there was a linear correlation between ΦHO• and ΦF. This suggests that different photophysical processes occur in the chemical components of the fractions (Lee et al. 12073–12080). As indicated by the results, the wastewater effluents produce a significant concentration of hydroxyl radical due to its formation as exhibited by the higher yields of quantum.

The studied results contributed important practices about the photochemical formation of hydroxyl radicals, which cannot be theoretically understood. This is because it exhibits the fundamental processes at which hydroxyl radicals are formed from EfOM, as well as the impacts on environmental factors and EfOM composition. The study specifically expands the basic understandings of the way photolytic processes are affected by the discharge of wastewater. This allows scientists and engineers to improve their understandings on the natural decay processes.
In addition, the results of the experiment can be used to enhance the quality of water models used tracing organic contaminants, especially in urban areas. Among the industrial application of the composition of hydroxyl radicals includes the industrial chemicals, pharmaceuticals, endocrine disruptor compounds, and the personal care products. This is because it helps the learners about the resulting chemical composition, especially in the exercise of removing reactive compounds from wastewater effluents. This includes focusing on engineered systems such as advanced membranes and oxidation systems.
In conclusion, the study helps the learner in understanding the formation of HO• from EfOM. It exhibits the essential for understanding wastewater-impacted aquatic systems because their results influence the mineralization of trace organic contaminants and photochemical degradations. The research study conducted also contributes to the fundamental information required by environmental scientists and engineers. The contribution includes differentiation of organic chemistry and the required information by an organic chemist (Ren 14-22).

The results from the experiment of the study have shown that the photochemical formation of HO• from effluent organic matters depends on the chemical properties of the available heterogeneous mixture. This was because the rate and amount of HO• formed increases on the samples with more apparent molecular weight and the bulkiness. Therefore, such studies should be regularly conducted to create awareness since organic chemist provides little or no information on the reactive nature of the by-products. This is in order to help environmental scientists and engineers to solve the hazardous waste and industrial problems.

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