Municipal and industrial wastewater blending: Effect of the carbon/nitrogen ratio on microalgae productivity and biocompound accumulation.

Municipal wastewater (MW) and industrial wastewater from juice processing (IWJ) were blended in different proportions to assess the effect of the carbon/nitrogen (C/N) ratio on pollutant removal, microalgal biomass (MB) cultivation, and the accumulation of carotenoids and biocompounds. MB development was not observed in treatments with higher C/N ratios (>30.67).

Biofuel from wastewater-grown microalgae: A biorefinery approach using hydrothermal liquefaction and catalyst upgrading.

Third-generation biofuels from microalgae are becoming necessary for sustainable energy. In this context, this study explores the hydrothermal liquefaction (HTL) of microalgae biomass grown in wastewater, consisting of 30% Chlorella vulgaris, 69% Tetradesmus obliquus, and 1% cyanobacteria Limnothrix planctonica, and the subsequent upgrading of the produced bio-oil. The novelty of the work lies in integrating microalgae cultivation in wastewater with HTL in a biorefinery approach, enhanced using a catalyst to upgrade the bio-oil.

Enhancing environmental performance in biogas production from wastewater-grown microalgae: A life cycle assessment perspective.

The production of biogas from microalgae has gained attention due to their rapid growth, CO sequestration, and minimal land use. This study uses life cycle assessment to assess the environmental impacts of biogas production from wastewater-grown microalgae through anaerobic digestion within an optimized microalgae-based system. Using SimaPro® 9 software, 3 scenarios were modeled considering the ReCiPe v1.

Wastewater-grown microalgae biomass as a source of sustainable aviation fuel: Life cycle assessment comparing hydrothermal routes.

The present paper compared, through life cycle assessment (LCA), the production of aviation biofuel from two hydrothermal routes of microalgae cultivated in wastewater. Hydrothermal liquefaction (HTL) and gasification followed by Fischer-Tropsch synthesis (G + FT) were compared. Both routes included biomass production, hydrotreatment for biofuel upgrading, and product fractionation.

Enhancing microalgae biomass production: Exploring improved scraping frequency in a hybrid cultivation system.

Recently, hybrid systems, such as those incorporating high-rate algal ponds (HRAPs) and biofilm reactors (BRs), have shown promise in treating domestic wastewater while cultivating microalgae. In this context, the objective of the present study was to determine an improved scraping frequency to maximize microalgae biomass productivity in a mix of industrial (fruit-based juice production) and domestic wastewater. The mix was set to balance the carbon/nitrogen ratio.

Aviation fuel based on wastewater-grown microalgae: Challenges and opportunities of hydrothermal liquefaction and hydrotreatment.

The current technical issues related to the conversion of algal biomass into aviation biofuel through hydrothermal liquefaction (HTL) and the upgrading of bio-oil through hydrotreatment have been reviewed and consolidated. HTL is a promising route for converting microalgae into sustainable aviation fuel (SAF). However, HTL must be followed by the hydrotreatment of bio-oil to ensure that its composition and properties are compatible with SAF standards.

Biocompounds from wastewater-grown microalgae: a review of emerging cultivation and harvesting technologies.

Microalgae biomass has attracted attention as a feedstock to produce biofuels, biofertilizers, and pigments. However, the high production cost associated with cultivation and separation stages is a challenge for the microalgae biotechnology application on a large scale. A promising approach to overcome the technical-economic limitations of microalgae production is using wastewater as a nutrient and water source for cultivation.

Microalgae biomass as a conditioner and regulator of soil quality and fertility.

Characteristics of an acid soil cultivated with Urochloa brizantha cv. Marandu were evaluated in relation to two types of fertilization: a conventional one, chemical based on nitrogen and potassium, and a biofertilizer, based on microalgae biomass. The results were compared among three treatments, control, conventional, and biological fertilization, with seven replications each.

Emerging microalgae-based biofuels: Technology, life-cycle and scale-up.

Microalgae biomass is a versatile feedstock with a variable composition that can be submitted to several conversion routes. Considering the increasing energy demand and the context of third-generation biofuels, algae can fulfill the increasing global demand for energy with the additional benefit of environmental impact mitigation. While biodiesel and biogas are widely consolidated and reviewed, emerging algal-based biofuels such as biohydrogen, biokerosene, and biomethane are cutting-edge technologies in earlier stages of development.

Copper multifaceted interferences during swine wastewater treatment in high-rate algal ponds: alterations on nutrient removal, biomass composition and resource recovery.

Microalgae cultivation in swine wastewater (SW) allows the removal of nutrients and biomass production. However, SW is known for its Cu contamination, and its effects on algae cultivation systems such as high-rate algal ponds (HRAPs) are poorly understood. This gap in the literature limits the proposition of adequate concentrations of Cu to optimise SW treatment and resource recovery in HRAPs.

Bioproducts from microalgae biomass: Technology, sustainability, challenges and opportunities.

Microalgae are a potential feedstock for several bioproducts, mainly from its primary and secondary metabolites. Lipids can be converted in high-value polyunsaturated fatty acids (PUFA) such as omega-3, carbohydrates are potential biohydrogen (bioH) sources, proteins can be converted into biopolymers (such as bioplastics) and pigments can achieve high concentrations of valuable carotenoids. This work comprehends the current practices for the production of such products from microalgae biomass, with insights on technical performance, environmental and economical sustainability.

Agro-industrial wastewater-grown microalgae: A techno-environmental assessment of open and closed systems.

Microalgae-based treatment can be applied to the bioremediation of agro-industrial wastewater, aiming at a circular economy approach. The present work compared the technical-environmental feasibility of operating a bubble column photobioreactor (PBR) and a high rate pond (HRP) for microalgae biomass production and wastewater treatment of a meat processing facility. The comparison was made regarding biomass productivity, phytoplankton composition, treatment efficiency, life cycle assessment, and energy balance.

Microalgae biomass as a renewable biostimulant: meat processing industry effluent treatment, soil health improvement, and plant growth.

Microalgae biomass contributes to effluent bioremediation. It is a concentrated source of nutrients and organic carbon, making it a potential alternative as a soil biostimulant. In this context, this study aimed to evaluate the soil application of microalgae biomass produced from the meat processing industry effluent treatment.

Swine wastewater treatment in high rate algal ponds: Effects of Cu and Zn on nutrient removal, productivity and biomass composition.

This study aimed to evaluate the simultaneous interferences of Cu and Zn found in swine wastewater (SW) in the development of microalgae considering real conditions of cultivation in high rate algal ponds (HRAPs). Ten HRAPs on a pilot scale were fed with SW with different mixtures of Cu (0.5-3.

Fires dynamics in the Pantanal: Impacts of anthropogenic activities and climate change.

Anthropogenic activities responsible for modifying climatic regimes and land use and land cover (LULC) have been altering fire behavior even in regions with natural occurrences, such as the Pantanal. This biome was highlighted in 2020 due to the record number of fire foci and burned areas registered. Thus, this study aimed to understand how changes in LULC and climate affect the spatial, temporal and magnitude dynamics of fire foci.

Evaluation of high rate ponds operational and design strategies for algal biomass production and domestic wastewater treatment.

This study evaluated the effect of high rate ponds (HRPs) depth on algal biomass production during domestic wastewater treatment. HRPs were evaluated for 20, 30, and 40 cm depths, with and without CO supplementation. In addition, 40 cm deep HRP with ultraviolet (UV) pre-disinfection was evaluated.

Characterizing Trophic State in Tropical/Subtropical Reservoirs: Deviations among Indexes in the Lower Latitudes.

Trophic state indexes (TSI) guide management strategies regarding eutrophication control worldwide. Such indexes usually consider chlorophyll-a (Chl-a), total phosphorus (TP), and Secchi disk depth (SDD) as independent variables for estimating aquatic productivity and the degree of impairment. TSIs for each of these components are frequently averaged to produce a single TSI value associated with a trophic state classification (e.

Valorization of swine wastewater in a circular economy approach: Effects of hydraulic retention time on microalgae cultivation.

To optimize the swine wastewater (SWW) treatment, this study investigated different hydraulic retention times (HRTs) for microalgae cultivation. For this purpose, five pilot-scale reactors operated in semi-continuous flow, with HRTs equal to 9, 12, 15, 18, 21 days were evaluated in terms of SWW polishing and biomass production. The effluent treatment was discussed accompanied by principal component analysis, which allowed identification of causes of variance in the data set, ideal for studies with real effluent and influenced by environmental conditions.

Decentralized management of sewage using septic tanks and anaerobic filters and its potential to comply with required standards in a developing country: a case study in Brazil.

To investigate the feasibility of implementing decentralized sewage treatment systems aiming to meet environmental standards, the performance of three decentralized wastewater treatment plants (WWTPs) comprising septic tanks and anaerobic filters (ST+AF) was evaluated. The ability of the WWTPs to comply with the provisions of the legislation and the technical literature was investigated by monitoring physical and chemical parameters at the entrance and exit of the WWTPs, from May 2017 to August 2018. Considering that factors such as operational routine, design of treatment systems, and the existence of pluvial contributions to the sewage network can influence the performance of WWTPs, an investigation of these factors was conducted.

Organomineral fertilizers pastilles from microalgae grown in wastewater: Ammonia volatilization and plant growth.

With the increasing demand for food, it is increasingly important to maintain soil fertility with the application of fertilizers to supply the nutritional needs of plants. However, the nutrients applied to the soil can suffer significant losses, impacting the environment, and increasing production costs. Using alternative sources, such as microalgae biomass (MB) generated in the treatment of wastewater, in the production of organomineral fertilizers is a way to recover nutrients from the sewage, in addition to contributing to the improvement in soil fertility and favoring crop growth, which can guarantee agricultural sustainability.

Future projections of water level and thermal regime changes of a multipurpose subtropical reservoir (Sao Paulo, Brazil).

The increase in global air temperatures as well as variability in rainfall shifts due to climate change has been affecting the dynamics of water level fluctuations and thermal regimes in lakes and reservoirs. It is expected that at the end of this decade, such impacts will be even more noticeable and may harm the inland waters use. However, little is known about the possible consequences of climate change in multipurpose subtropical reservoirs.

A life cycle assessment of energy recovery using briquette from wastewater grown microalgae biomass.

Microalgae biomass (MB) is a promising source of renewable energy, especially when the cultivation is associated with wastewater treatment. However, microalgae wastewater technologies still have much to improve. Additionally, microalgae biomass valorization routes need to be optimized to be a sustainable and feasible source of green bioenergy.

Hydrothermal carbonization of microalgae biomass produced in agro-industrial effluent: Products, characterization and applications.

Hydrothermal carbonization is a thermochemical treatment whose objective is to convert carbohydrate components of a given biomass into carbon-rich material in an aqueous medium. Biomass of wastewater grown microalgae is among the various potential biomasses for this route. However, operational parameters of hydrothermal carbonization for different types of biomass are still being investigated.

Ecosystem service valuation method through grey water footprint in partially-monitored subtropical watersheds.

The valuation of ecosystem services of pollution regulation in basins with partial monitoring does not have only one consolidated methodology which can be applied in all countries, biomes and across spatio-temporal scales. While different metrics can incorporate elements of uncertainty for decision makers, changes in land use, climate and sectoral demands in basins increase the need for the efficiency and complexity of valuation methods. Here, based on adapting a pre-existing method, we present a new ecosystem service valuation applied to river basins under different characteristics in the biomes of the Atlantic Forest and Brazilian savannah.