Planning of wastewater treatment systems inside watersheds based on water quality simulation model and optimization techniques
Name: Thiara Cezana Gomes
Type: PhD thesis
Publication date: 22/08/2022
Advisor:
Name |
Role |
|---|---|
| Antonio Sérgio Ferreira Mendonça | Advisor * |
| Rodrigo de Alvarenga Rosa | Co-advisor * |
Examining board:
| Name |
Role |
|---|---|
| Antonio Sérgio Ferreira Mendonça | Advisor * |
| FERNANDO DAS GRAÇAS BRAGA DA SILVA | External Examiner * |
| Gisele de Lorena Diniz Chaves | Internal Examiner * |
| José Antônio Tosta dos Reis | Internal Examiner * |
| Leandro Colombi Resendo | External Examiner * |
| Rodrigo de Alvarenga Rosa | Co advisor * |
Summary: In Brazil, the sewage treatment services coverage levels are low. Sewage treatment systems
setting up, operating and maintaining costs are generally high and vary considerably depending
on the technology type to be implemented. Given this scenario, this research proposed a method
for planning effluent treatment systems involving minimization of sewage treatment and
transport costs, considering the current legislation, systemic vision in which the river basin is
assumed as a planning unit and water bodies self-depuration capacities. The integrated
modeling was supported by three modules: (i) water quality mathematical modelling combined
with optimization technique to estimate minimum sewage treatment efficiencies, (ii) hydraulic
calculations and (iii) Facility Location Problem (PLF). The study differs from others by
integrating organic material removal efficiencies into Wastewater Treatment Plant (WTP)
locations choice process, by considering self-purification capacity of water bodies and by
discussing Consortium Effluent Treatment (CET). In the CET, the effluents generated by
different point sources are transported and grouped in ETEs presenting greater capacities,
providing centralized networks. The methodology was applied to the Pardo watershed, in
Espírito Santo state, Brazil. In total, 22 scenarios for water quality modeling were created,
subdivided into two groups: individual WTPs and CET. In order to consider the method`s
sensitivity to parameter variations, four analysis quadrants were developed being a key concept
worked in each of them. The adoption of the CET concept proved to be viable, especially for
networks presenting smaller lengths, sets of high sewage treatment efficiencies and/or increased
scale economies. When considering the growing global population and cities facing budget
constraints, paradigms changes and search for economically and environmentally safe solutions
are very valuable.
