Search

All over the world, the oceans are the final destination of sewage transported by river estuaries, rainwater and other coastal discharges. The risks to human health related to direct contact with water and consumption of contaminated fish are well known, but little is known about the potential for atmospheric exposure to pollutants and pathogens from contaminated seawater. The release of microbial particles from the sea into the atmosphere occurs mainly by the eruption of rising bubbles through the sea surface microlayer (SML) or by sea spray. We investigated the heterotrophic bacteria density and relative abundance in SML and bioaerosols originated on the seafront of Fortaleza (Atlantic coastal zone, northeastern Brazil) influenced by wastewater disposal. There was a difference in the density of total heterotrophic bacteria (THB) according to the matrix analyzed during two seasons: the bacterial count was highest in the SML during the rainy season while the highest number of bacteria in bioaerosols samples was recorded during the dry season. Twenty-nine bacterial taxonomic groups were identified with variable abundance for both environments. These were the same in both matrices, with environmental variables influencing their abundance and composition. The contribution of the marine and continental environments in shaping the microbiota of the SML and coastal bioaerosols was clear, with the constant and representative presence of Enterobacteria standing out. The aerosolization of bacteria resulting from the discharge of untreated sewage is an important issue related to coastal environmental health and ecological safety., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The anthropization of terrestrial environments has increased the production and concentration of nutrients and organic compounds in shallow bodies of water and in the soil along river banks, thereby causing changes in both water and soil quality. To examine the impact of anthropization on river environments, the phosphorus, potassium, and carbon content in the water and the phosphorus, potassium, and organic matter in the soil were analyzed at eighteen sites. The experimental area is located in an urbanized drainage basin located in the municipality of Lages, Santa Catarina (southern Brazil). The water samples were collected in two field surveys. The first one occurred between August and December 2016, and the second took place from March to June 2017. The soil samples were collected in one field survey from August 2016 and June 2017. The 18 sites were regularly distributed across forests, native grasslands, and urban areas. The dissolved phosphorus and potassium in the water were obtained by applying the methodology proposed by MURPHY & RILEY (1962), whereas the dissolved carbon in the water was mineralized by combustion using an oven at 800 ºC and calculated with the Analytik Jena Multi N/C 2100 TOC/TN Analyzer. On the other hand, the extractable phosphorus and potassium from the soil and organic matter were determined with the methodology described by TEDESCO et al. (1995). The results demonstrated that the concentration of dissolved phosphorus, potassium, and carbon in the water was greater in the parts of the river that cross through urban areas than in the parts of the river that course through grasslands and forests throughout practically the entire year. The same trend was observed with the phosphorus and potassium content in the soil along the river banks. However, the organic matter content in the soil was lower in the sections located in urban areas. The findings indicate that in urban areas where sewage treatment is either nonexistent or deficient, the release of domestic wastewater containing household detergents and soaps contributes to the increase in the content of phosphorus, potassium, and carbon in the water and phosphorus and potassium in the soil. [ABSTRACT FROM AUTHOR]

The research developed a combined system in batch flow and in pilot scale for the treatment and reuse of urban effluents. The system was fed raw effluent from a university campus in Brazil and composed of four anaerobic reactors, three constructed wetlands (CWs) and an ozonation unit. The three sequential hybrid constructed wetlands were composed of a floating treatment wetland, an aerobic-anoxic baffled constructed wetland (CW) and a saturated vertical flow CW. Later, during the last trimester, weekly samples of the treated effluent were ozonated by bubbling with an application rate of 240 mg.h-1 O3. The system presented high removal rates efficiencies in terms of carbonaceous organic matter (78.9%), nitrogen (91.0%), color (96.7%) and turbidity (99.1%). In addition, it worked well for disinfection and acute ecotoxicity, but P was only efficiently (75%) removed in the first 8 months, with removing efficiency declining after this period. Ozonation provided significant color removal and an increased pH. The combination of floating, alternated upflow and downflow and saturated vertical flows improved the treatment of wastewater. This was due to the presence of both aerobic and anaerobic zones, as well as the filter substrate, through an integrated system with simple construction and operation and increased lifespan. [ABSTRACT FROM AUTHOR]

This study investigated the behaviour of two intermittently fed vertical flow constructed wetlands (one planted with Tifton 85 and the other unplanted) working in parallel, treating raw municipal sewage in Brazil for a population equivalent around 100 inhabitants. Based on a monitoring programme of over 2 years, the following items were evaluated: influence of batch frequency and the presence of Tifton 85 on the wetlands performance in terms of several physico-chemical and biological constituents. The unit with plants performed better than the one without, indicating a positive influence of the presence of plants. More attachment by total and volatile solids and larger amount of bacteria involved in the nitrogen cycle were observed in the planted filter medium, which can explain its higher nitrification and solids removal. The application of a smaller influent volume with a higher batch frequency improved the performance of both units. No signs of medium clogging have been observed in both units. The system simplicity and the good removal efficiency of organic matter, suspended solids, ammonia and helminth eggs indicate its high applicability in small communities in developing countries such as Brazil. [ABSTRACT FROM AUTHOR]

The paper analyses the concept and performance of different configurations of compact UASB/TF systems, without the final clarification stage, in relation to the removal of organic matter. The experiments were carried out in two sets of UASB/TF systems operating without secondary clarifiers, as follows: (i) four shallow (2.50 m height) TFs, each one filled with a different packing material; and (ii) two deep (4.20 m height) TFs, one filled with polyethylene corrugated sheets and the other with mixed polyethylene and sponge sheets. For the conditions tested (different packing material in shallow and deep TF), the UASB/TF systems had consistently complied (90 to 100% of the results) with the Brazilian discharge standards regarding to BOD, COD, and TSS parameters. The average BOD, COD and TSS effluent concentrations stayed below 40 mg BOD L-1, 100 mg COD L-1 and 50 mg TSS L-1, respectively. UASB/TF systems can constitute an attractive alternative for domestic wastewater treatment in small communities in developing countries, especially considering its operational simplicity and very low running costs. [ABSTRACT FROM AUTHOR]

The paper analyses the concept and performance of compact UASB/TF systems in relation to configuration, use of innovative packing media and operational conditions. For the conditions tested, the UASB/TF systems had consistently complied with the Brazilian discharge standard regarding to COD, BOD and TSS parameters. However, some enhancements are still necessary in order to increase nitrification in the process. The conditions to promote nitrification in shallow TF (packed bed up to 2.50m height) seem to be compatible with the proposed simplification in the flowsheet, which is to operate the system without secondary clarifiers. [ABSTRACT FROM AUTHOR]

In this study, the efficiency of contaminant removal from a compact wastewater treatment plant (CWTP) in a university campus under different rain conditions was evaluated. Wastewater samples were collected weekly for 1 year and the physicochemical parameters were monitored. Removal efficiency higher than 77%, reaching values above 95% for samples with lower wastewater flow rates, was found for biological oxygen demand (BOD) and total and fecal coliforms. The pH values remained in the range of 6.0-8.0. However, pH values below 6.8 impaired the nitrification rate and, therefore, the removal of total Kjeldahl nitrogen (TKN) and ammonia was lower than the expected, with concentration values above those set by the Brazilian regulation for wastewater discharge. The results show that the flow rate of wastewater at the entrance of the CWTP is directly related to the rain events, thus affecting its efficiency, mainly in the removal of total solids, turbidity, and organic matter. The assessment of the treated wastewater reuse on site for agricultural purposes showed to be a prominent and more sustainable alternative regarding the discharge of wastewater into water bodies.

Along the coastal zone of the State of São Paulo, Brazil, diffuse discharges that flow directly to tourist beaches are responsible for introducing various pathogens into recreational waters. The objective of this study was to analyze, for the first time, the presence of protozoa (Cryptosporidium ssp and Giardia ssp), as well as human mastadenoviruses (HAdV-species C and F) and other species of adenoviruses (AdV) in beach drainage channels of Enseada and Perequê, municipality of Guarujá, São Paulo, Brazil. Protozoa were not detected in any sample over the course of the 11-month study. In relation to HAdVs, 100% (n = 22) of the water samples presented contamination by at least one type of virus (C, D, or F species), suggesting potential risks to the public health following recreational exposure of beach users to these waters. PRACTITIONER POINTS: First report on the presence of human adenoviruses in urban drainage channels in the coast of São Paulo State, Brazil. Urban surface water runoff is responsible for introducing human adenoviruses linked to disease outbreaks in areas of intense recreation. Cryptosporidium oocysts and Giardia cysts were below the limit of detection for all analyzed samples. However, all sites were positive for at least one of the viral species (HAdV-C, HAdV-D, or HAdV-F). Viral loads found in the water were similar to those commonly found in the wastewater., (© 2020 Water Environment Federation.)