| Author | Mian, Mohammad Haneef |
| Call Number | AIT Thesis no.EV-97-27 |
| Subject(s) | Water--Purification--Chlorination
|
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of
Engineering |
| Publisher | Asian Institute of Technology |
| Abstract | Concern about the increased level of trihalomethanes on chlorination of the waters containing algae especially cyanobacteria led to this investigation. This study was undertaken support the fact that algae play an important role in the formation of trihalomethanes in chlorinated drinking waters. As it was believed that the trihalomethanes were produced on reaction of the chlorine with algae as well as the extracellular products of algae, both these approaches were pursued during this study. Standard components of the algogenic organic matter (AOM) were bought commercially. The trihalomethane formation potential of each of these components with varying chlorine doses was studied. The analysis was carried out by means of headspace method using a gas chromatograph (GC/ECD). It was revealed that the individual components of algogenic organic matter (AOM) can be the precursors of THM's. The experiments for each of the components were conducted in both light and dark conditions. The production of high amount of chloroform in the dark and the consumption of high chlorine dose in the light led to the fact that, light plays an important role in the production of chloroform (which makes up more than 98% of THM's). In most of the water treatment plants usually prechlorination is carried followed by alum coagulation of the water. However, no literature was found using intermediate chlorination after alum coagulation of the water sample containing algae. Experiments were conducted with algal laden lake samples using only chlorination of the sample, prechlorination of the sample and intermediate chlorination of the sample. Alum was used for coagulation of the samples. This part of the study led to the fact that prechlorinated algal samples produced 30- 40% less chloroform as compared to only chlorination, while intermediate chlorination produced 25-50% less chloroform as compared to prechlorination. This is a major addition to the literature, as there is no evidence of a study comparing prechlorination and intermediate chlorination with reference to production of THM's and there suitability for treatment processes. The dependency of production of chloroform on several factors including light, temperature, contact time and initial chlorine dose were some of the results of the study. |
| Year | 1997 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Energy and Climate Change (Former title: Department of Energy, Environment, and Climate Change (DEECC)) |
| Academic Program/FoS | Environmental Engineering (EV) |
| Chairperson(s) | Ishibashi, Yoshinobu; |
| Examination Committee(s) | Preeda Pakpian;Takizawa, Satoshi;Kamei, Tasuku; |
| Scholarship Donor(s) | The Government of Japan; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1997 |