Conventional wastewater treatment plants (WWTPs) present low phosphorus (P) removal capacity. Conversely, water treatment plants (WTPs) produce sludge with great P sorption from wastewater; however, directly adding the sludge into the wastewater treatment system could increase the effluent turbidity. As a novel approach, the present study evaluated the performance of WTP sludge within paper sachets for P removal from treated sewage. Different sludge concentrations (2–30 g L−1) and contact times (1–27 d) were applied to treat sewage from a university WWTP outlet. The sludge was characterized by P, Fe, and Al content. Larger sludge masses showed higher P removal efficiencies due to their high Fe content, especially at longer contact times (up to 100% at the final of the experiment). However, there is a more significant P reduction in the first 10 d (more than 90% in the most efficient treatment – 30 mg L−1). Based on the kinetic and isotherm analyses and the sludge chemical composition, precipitation proved to be a mechanism of great importance in P removal. Therefore, WTP sludge sachets can be a promising way to remove P from sewage, and the formed solid waste might be reused as an alternative fertilizer.

O esgoto contém grande diversidade de microrganismos, incluindo patógenos como os vírus, sendo, portanto, um meio propício para identificação da circulação de doenças infectocontagiosas – técnica conhecida como wastewater-based epidemiology (WBE). A WBE se mostra uma poderosa ferramenta de saúde pública para rastrear e sinalizar a situação epidemiológica da população, visto que as partículas virais do SARS-CoV-2 podem ser expelidas nas fezes e urina dos contaminados antes mesmo do surgimento de sintomas e do diagnóstico clínico de COVID-19. Este estudo apresenta uma revisão de literatura sobre a presença de SARS-CoV-2 e outros vírus no esgoto doméstico e as possibilidades de remoção em estações de tratamento de esgoto (ETEs) convencionais e avançadas, bem como as técnicas de concentração e detecção em amostras ambientais. Ao final do artigo, foi apresentada uma análise econômica da aplicabilidade da WBE como instrumento de predição epidemiológica da COVID-19 em um município brasileiro. Palavras-chave: Água residuária doméstica. Novo coronavírus. Pandemia de COVID-19. Monitoramento epidemiológico do esgoto. Virologia.

The golden mussel (Limnoperna fortunei) poses environmental and infrastructural challenges due to its ability to attach to various substrates and form dense colonies. These colonies are difficult to remove and threaten hydroelectric power stations, water treatment plants and fishing activities. However, the high calcium carbonate content of golden mussel shells (GMSs) presents an opportunity for phosphorus (P) recovery from wastewater, addressing both waste management and resource scarcity. This study evaluated the effectiveness of GS for P recovery from synthetic and real wastewater. Batch experiments were conducted to assess P recovery capacity under varying adsorbent dosages, pH levels, contact times and isotherm conditions (Langmuir, Freundlich and Temkin). Also, the chemical and physical analyses of GMSs were performed to elucidate the mechanisms of P recovery. The Freundlich isotherm model best describes the process, while the Langmuir model suggests a maximum recovery potential of approximately 59.9 mg P g⁻¹ of GMS, demonstrating a P recovery efficiency of up to 60.7% at a P concentration of 40–50 g L⁻¹ and a contact time of 3 h. Due to the predominance of negative charges, it was concluded that the precipitation was the major mechanism for P recovery by GS. This study highlights the potential of GMSs as a sustainable and low-cost material for phosphorus recovery in wastewater treatment, offering a promising solution for both waste valorization and environmental management contributing to a circular economy.