Avaliação da influência da cobertura e disposição de jardins flutuantes na eficiência do tratamento de esgotos domésticos.

Abstract

Wastewater treatment is a global challenge, especially in developing countries where limited infrastructure results in low sewage treatment rates. In this context, nature-based solutions, such as phytoremediation, have gained prominence due to their low cost and minimal environmental impact. Among these solutions, Floating Treatment Wetlands (FTW), also known as Floating Gardens Systems (SJF), have emerged as a promising alternative. In Brazil, stabilization ponds are widely used for domestic sewage treatment. To enhance their efficiency without significant investments, particularly in single-lagoon systems, the use of FTW presents an innovative approach. This study aimed to evaluate the influence of FTW coverage and arrangement on the efficiency of domestic sewage treatment, proposing modifications to the system previously designed and analyzing the performance of a new configuration. The research was conducted at the Glória Wastewater Treatment Plant (ETE), located in Campina Grande – Paraíba, Brazil. A bioassay was conducted to test the adaptation of four plant species (Canna indica, Xanthosoma sagittifolium, Tradescantia pallida, and Heliconia psittacorum). Simultaneously, the existing FTW without maintenance (SM) was monitored to assess its efficiency and lifespan. After removing the SM, a new system (SN) with improved design was implemented. The SN's performance was monitored through physicochemical and biological analyses of water quality to identify the optimal treatment configuration. The bioassay results showed good development for C. indica and X. sagittifolium, while T. pallida and H. psittacorum exhibited moderate performance. In the SM, EPS structures showed signs of wear, and excessive biomass growth was observed. The SN demonstrated higher removal efficiencies for turbidity (73.30%), electrical conductivity (28.58%), COD (79.84%), phosphorus (46.84%), ammoniacal nitrogen (48.76%), and coliforms/pathogens (99,74%). Therefore, considering the removal efficiency, required coverage area, and plant survival, the SN proved to be the best option to complement domestic sewage treatment.