عنوان
پدید آورنده
موضوع
رده
کتابخانه
محل استقرار
TL53501
انگلیسی
Degradation of Ternary Mixture of Trihalomethanes in a Biotrickling Filter in the Presence of Biosurfactant and Fungi
[Thesis]
Islam, Sanaiya
University of Cincinnati
2020
73 p.
M.S.
University of Cincinnati
2020
Trihalomethanes (THMs) are a group of volatile organic compounds, used widely in the industries as solvents. The presence of THMs in the environment can cause air, water and soil pollution. The compound constituting THMs are Chloroform (CF), Bromodichloromethane (BDCM), Dibromochloromethane (DBCM), and Bromoform (BF). These compounds are toxic in nature and deemed potential carcinogenic to human. The US Environmental Protection Agency has provided a strict maximum contaminant level (MCL) for THMs in water. In air and soil pollution, the hazard level is set at different values for the four constituents. To reduce air pollution due to THMs emission, physical as well as chemical methods can be adapted. Among, the available technologies, it is essential to find a method that is effective, easy to operate, cost effective and eco-friendly. The use of aerobic biotrickling filter (BTF) with filamentous fungi as biodegrading organism, had proven to have significant impact on removal of CF in the presence of cometabolites from the gaseous phase. The current research study evaluates the significance of an aerobic BTF in bioremediation of a ternary mixture of the three compounds of the THMs group, CF, BDCM and DBCM. A state-of-art BTF was set up for the study, which was seeded with filamentous fungal consortium and biosurfactant, at the beginning of the study. The biosurfactant was synthesized from Bacillus subtilis and their attribute to accumulate at the interface of air and water due to their amphiphilic molecular structure was utilized to ensure the microbial growth in the system. The biosurfactant also enhanced the interaction between the volatile THMs mixture and biofilm surface. A pH 4 nutrient solution containing the essential growth vitamins and minerals required for the biomass was supplied to the system at a constant rate of 2 liter/day. The system was kept under acidic condition to ensure the growth of fungi colonies. A gas stream containing the ternary mixture was treated within the BTF system. The objective of this study is to observe the performance of the BTF for different concentration of the THMs compounds. While most studies focus on the singular or binary mixture of the constituent removal, this study focuses on a ternary mixture of the THMs which can mimic the complex industrial elimination. The ternary mixture containing different proportion of the THMs for projected concentrations for each contaminant was fed to the system using an air stream. Another important parameter evaluated in this study was the empty bed residence time (EBRT). The project was started with an EBRT of 5 minutes and was gradually reduced to 30 seconds. The effect of the lower EBRT was studied to gauge the applicability of the BTF in a rapid industrial effluent remission. During the study, 66.4%-92.1%, 72.3%-89.5% and 76.3%-91.9% were achieved for CF, BDCM, and DBCM, respectively, were achieved in the different experimental phases.
Engineering
Environmental engineering
Islam, Sanaiya
University of Cincinnati
مطالعه متن کتاب p
[Thesis]
276903
a
Y
