Enhances pathogen removal in constructed wetlands using nanosilver coated on filter media from dewatered sludge | |
| Author | Chanya Kloysuwan |
| Call Number | AIT Thesis no.EV-24-03 |
| Subject(s) | Sewage--Purification Septic tanks--Environmental aspects Water reuse |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Environmental Engineering and Management |
| Publisher | Asian Institute of Technology |
| Abstract | Septic tanks are frequently employed as part of enhanced offsite sanitation systems in rural regions of numerous developing countries (Kihila & Balengayabo, 2020). There have been proposals to utilize constructed wetland systems (CWs) as effective post-treatment mechanisms in pursuit of enhancing the treatment efficacy of septic tank technology. This study utilized filter media coated with AgNPs to assess the efficacy of pathogen eliminate in vertical subsurface flow (VSSF) constructed wetlands containing septic tank effluent. Utilizing sophisticated adsorbent media, the study aimed in order to enhance overall efficacy of CWs with regard to of pathogen eliminate. The filter media was composed of bentonite and desiccated sediment. AgNPs were produced via a chemical reduction process. PVP capped AgNPs are capable of depositing a thin film onto the micropore surface of media. Observing changes in parameters including pH, COD, NO2 - -N, NO3 - -N, NH3-N, Fecal coliform, and Escherichia coli is a subsequent method for determining efficiency. In addition to inhibiting bacterial growth, the nanocomposite can cause pathogen cell membrane injury. Fecal coliforms and E. coli present in effluent could be rendered inactive by nano-silver coated filter media with a 4.84 and 4.94 Log10 reduction, respectively, after 6 hours of HRT. The experiments conducted in this research revealed that wastewater treated in nano silver units had a slightly greater concentration of fecal coliform compared to the WHO Guidelines. However, this level of contamination slightly higher than WHO guidelines, indicating that the treated wastewater may be safely reused in agricultural practices. In contrast, nitrate in CWs was negatively affected by nano-silver, leading to a substantial increase in nitrate concentration. It was determined from this study that CWs employing adsorptive media coated with AgNPs were extraordinarily effective at eliminating pathogens; however, other parameters were unsuitable for elimination. In this experiment, it can be applied to constructed wetlands which receive wastewater that has been treated with two to three treatments such as COD, NH3, NO2 and other pollutants. |
| Year | 2024 |
| Type | Thesis |
| School | School of Environment, Resources, and Development |
| Department | Department of Energy and Climate Change (Former title: Department of Energy, Environment, and Climate Change (DEECC)) |
| Academic Program/FoS | Environmental Engineering and Management (EV) |
| Chairperson(s) | Thammarat Koottatep |
| Examination Committee(s) | Chongrak Polprasert;Xue, Wenchao |
| Scholarship Donor(s) | Royal Thai Government;AIT Scholarships |
| Degree | Thesis (M. Sc.) - Asian Institute of Technology, 2024 |