RESUMO

Due to the constant growth of the human population and anthropological activity, it has become necessary to use sustainable and affordable technologies that satisfy the current and future demand for agricultural products. Since the nutrients available to plants in the soil are limited and the need to increase the yields of the crops is desirable, the use of chemical (inorganic or NPK) fertilizers has been widespread over the last decades, causing a nutrient shortage due to their misuse and exploitation, and because of the uncontrolled use of these products, there has been a latent environmental and health problem globally. For this reason, green biotechnology based on the use of microalgae biomass is proposed as a sustainable alternative for development and use as soil improvers for crop cultivation and phytoremediation. This review explores the long-term risks of using chemical fertilizers for both human health (cancer and hypoxia) and the environment (eutrophication and erosion), as well as the potential of microalgae biomass to substitute current fertilizer using different treatments on the biomass and their application methods for the implementation on the soil; additionally, the biomass can be a source of carbon mitigation and wastewater treatment in agro-industrial processes.

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Phytoplankton composition and abundance are considered among the bioindicators of variations in water quality, due to its sensitivity and rapid responses to changes in environmental parameters. The selection and scaling of the Microalgal Predominant Microbial Consortium (MPMC) were based on live samples collected from the Santiago Apóstol Swamp (SAS) and the Arroyo Grande de Corozal (AGC). The inoculum was scaled in a phycoculture plant, and the inoculation process was performed in the AGC that flows into the SAS. The phytoplankton community monitoring was performed from May 2019 to September 2021. In the process, a total of 1,652,258 gallons were inoculated. Precisely, 103 and 124 species were found in the AGC and SAS, respectively. By evaluating the physical, chemical, and microbiological variables in SAS in a multitemporal way based on the inoculation of the MPMC, it is possible to identify the variables that presented the greatest reduction. The density of SAS presented associations with dissolved oxygen, thermotolerant coliforms, Enterococci, pH, phosphorus, nitrates, speed, and Secchi. The AGC and SAS presented high trophic levels (eutrophication). This contamination by organic matter is probably due to the discharges of the domestic tributaries. The diversity of microalgae and cyanobacteria found in this study allows us to know the anthropogenic impact. The density of microalgae showed the positive impact of the treatment with MCPM, where there was a decrease in the species that denote organic contamination. The phytoremediation treatment was effective in terms of the changes observed in the physicochemical variables, and these changes were directly due to the efficiency of the treatment and not the natural behavior of the water sources in the region.

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In this work, we evaluated the removal efficiency of diclofenac by Chlorella vulgaris OW-01, Nannochloropsis oculata CCAP 849/7, Scenedesmus acutus UTEX 72, and Scenedesmus obliquus CCAP 276/2. Each microalga was grown in media with different concentrations (50 and 100% of the original formulation) of carbon, nitrogen, and phosphorus, to evaluate their effect on the removal of diclofenac. We also evaluated the photodegradation of diclofenac under the same conditions. The diclofenac removed from the media ranged from 59 to 92%, obtaining the highest removal with S. obliquus. The diclofenac adsorbed on the cell walls ranged from 12.2 to 26.5%, obtaining the highest adsorption with S. obliquus. The diclofenac degraded by light ranged from 15 to 28%. The nutrient deficit showed no influence on the removal of diclofenac in any of the microalgae under study. These results indicate that S. obliquus is the best alternative for the bioremediation of diclofenac. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-022-03268-2.

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Bioaugmentation has many applications as a bioremediation technique. It is usually performed by bacteria but microalgal consortia also have great potential for bioremediation. This study evaluated the ability of a microbial consortium with predominance of microalgae (MCPM) to decontaminate the water of the Mallorquín tropical swamp. The Mallorquín Swamp is a natural water reservoir, essential for the ecological and hydric balance of the region, as well as for the fishermen, but has received sewage for more than 20 years. Microalgae for bioremediation purposes were isolated from the swamp, selected, cultured in bioreactors, and poured back into the Mallorquín waters. After bioaugmentation, there was a significant reduction in the BOD5 (98%), nitrates (58%), enterococci (92%), and total coliforms (100%). Notably, despite the MCPM bioaugmentation, the original richness and abundance of phytoplankton in the Mallorquín swamp was not disrupted. These results confirm the benefits of phycoremediation as an effective tool for on-site bioremediation of natural water bodies and show an effective phycoremediation at a large scale without altering the autochthonous microalgae community. This constitutes the first report of a successful MCPM intervention performed at this scale in a natural swamp in Colombia. Supplementary Information: The online version contains supplementary material available at 10.1007/s12088-021-00990-y.

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Abstract A feasibility analysis of tertiary treatment for Organic Liquid Agricultural Waste is presented using filamentous algae belonging to the genus Cladophora sp. as an alternative to chemical tertiary treatment. The main advantages of tertiary treatments that use biological systems are the low cost investment and the minimal dependence on environmental variables. In this work we demonstrate that filamentous algae reduces the nutrient load of nitrate (circa 75%) and phosphate (circa 86%) from the organic waste effluents coming from dairy farms after nine days of culture, with the added advantage being that after the treatment period, algae removal can be achieved by simple procedures. Currently, the organic wastewater is discarded into fields and local streams. However, the algae can acquire value as a by-product since it has various uses as compost, cellulose, and biogas. A disadvantage of this system is that clean water must be used to achieve enough water transparency to allow algae growth. Even so, the nutrient reduction system of the organic effluents proposed is friendly to the ecosystem, compared to tertiary treatments that use chemicals to precipitate and collect nutrients such as nitrates and phosphates.

Resumo Uma análise de viabilidade do tratamento terciário para Resíduos Agrícola Líquidos Orgânicos é apresentada usando algas filamentosas pertencentes ao gênero Cladophora sp. como alternativa ao tratamento químico terciário. Os tratamentos terciários que utilizam sistemas biológicos têm baixo custo de investimento e a dependência de variáveis ​​ambientais é mínima. Neste trabalho, é demonstrado que essas algas filamentosas reduzem a carga nutricional de nitrato (circa 75%) e fosfato (circa 86%) dos efluentes de resíduos orgânicos provenientes de fazendas de leite em nove dias de cultura e tem a vantagem de que as algas podem ser facilmente coletadas posteriormente. Atualmente, as águas residuais orgânicas são descartadas nos campos e córregos locais. Posteriormente, as algas podem ser consideradas como matéria prima, uma vez que possuem várias utilidades como composto, celulose e biogás. Uma desvantagem desse sistema é que água limpa deve ser usada para obter transparência de água suficiente para permitir o crescimento de algas. Mesmo assim, o sistema de redução de nutrientes dos efluentes orgânicos propostos e amigável ao ecossistema, comparado aos tratamentos terciários que utilizam produtos químicos para precipitar e coletar nutrientes como nitratos e fosfatos.

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RESUMO

A feasibility analysis of tertiary treatment for Organic Liquid Agricultural Waste is presented using filamentous algae belonging to the genus Cladophora sp. as an alternative to chemical tertiary treatment. The main advantages of tertiary treatments that use biological systems are the low cost investment and the minimal dependence on environmental variables. In this work we demonstrate that filamentous algae reduces the nutrient load of nitrate (circa 75%) and phosphate (circa 86%) from the organic waste effluents coming from dairy farms after nine days of culture, with the added advantage being that after the treatment period, algae removal can be achieved by simple procedures. Currently, the organic wastewater is discarded into fields and local streams. However, the algae can acquire value as a by-product since it has various uses as compost, cellulose, and biogas. A disadvantage of this system is that clean water must be used to achieve enough water transparency to allow algae growth. Even so, the nutrient reduction system of the organic effluents proposed is friendly to the ecosystem, compared to tertiary treatments that use chemicals to precipitate and collect nutrients such as nitrates and phosphates.(AU)

Uma análise de viabilidade do tratamento terciário para Resíduos Agrícola Líquidos Orgânicos é apresentada usando algas filamentosas pertencentes ao gênero Cladophora sp. como alternativa ao tratamento químico terciário. Os tratamentos terciários que utilizam sistemas biológicos têm baixo custo de investimento e a dependência de variáveis ambientais é mínima. Neste trabalho, é demonstrado que essas algas filamentosas reduzem a carga nutricional de nitrato (circa 75%) e fosfato (circa 86%) dos efluentes de resíduos orgânicos provenientes de fazendas de leite em nove dias de cultura e tem a vantagem de que as algas podem ser facilmente coletadas posteriormente. Atualmente, as águas residuais orgânicas são descartadas nos campos e córregos locais. Posteriormente, as algas podem ser consideradas como matéria prima, uma vez que possuem várias utilidades como composto, celulose e biogás. Uma desvantagem desse sistema é que água limpa deve ser usada para obter transparência de água suficiente para permitir o crescimento de algas. Mesmo assim, o sistema de redução de nutrientes dos efluentes orgânicos propostos e amigável ao ecossistema, comparado aos tratamentos terciários que utilizam produtos químicos para precipitar e coletar nutrientes como nitratos e fosfatos.(AU)

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Greenhouse gases (GHG) emissions are widely related to climate change, triggering several environmental problems of global concern and producing environmental, social, and economic negative impacts. Therefore, global research seeks to mitigate greenhouse gas emissions. On the other hand, the use of wastes under a circular economy scheme generates subproducts from the range of high to medium-value, representing a way to help sustainable development. Therefore, the use of wastewater as a culture medium to grow microalgae strains that biocapture environmental CO2, is a proposal with high potential to reduce the GHG presence in the environment. In this work, Scenedesmus sp. was cultivated using BG-11 medium and industrial wastewater (IWW) as a culture medium with three different CO2 concentrations, 0.03%, 10%, and 20% to determine their CO2 biocapture potential. Furthermore, the concomitant removal of COD, nitrates, and total phosphorus in wastewater was evaluated. Scenedesmus sp. achieves a biomass concentration of 1.9 g L-1 when is grown in BG-11 medium, 0.69 g L-1 when is grown in a combination of BG-11 medium and 25% of industrial wastewater; both cases with 20% CO2 supplied. The maximum CO2 removal efficiency (8.4%, 446 ± 150 mg CO2 L-1 day-1) was obtained with 10% CO2 supplied and using a combination of BG-11 medium and 50% IWW (T2). Also, the highest removal of COD was reached with a combination of BG-11 medium and T2 with a supply of 20% CO2 (82% of COD removal). Besides, the highest nitrates removal was achieved with a combination of BG-11 medium and 75% IWW (T3) with a supply of 10% CO2 (42% of nitrates removal) and the maximum TP removal was performed with the combination of BG-11 medium and 25% IWW (T1) with a supply of 10% CO2 (67% of TP removal). These results indicate that industrial wastewater can be used as a culture media for microalgae growth and CO2 biocapture can be performed as concomitant processes.

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Ethidium Bromide (EtBr) is an organic compound used in molecular biology investigations. EtBr ability of intercalating in the DNA molecule makes it a toxic substance. The objective was to evaluate the phycoremediation potentials of Chlorella vulgaris, Desmodesmus subspicatus and Raphidocelis subcapitata tested separately and in a mixture (Mix) for EtBr removal from the aqueous medium. Experiments were conducted using an initial algae biomass of 106 cell/mL, exposed to 500 µg/L of EtBr. The removal efficiency (µg EtBr L-1) after 3 h in each treatment were: Mix (72.8 µg.L-1) >D. subspicatus (48.4 µg.L-1) >R. subcapitata (24.6 µg.L-1) >C. vulgaris (19.9 µg.L-1). However, when EtBr mass reduction per microalgae density is considered (ng.algae-1), the efficiency ranking changes to: D. subspicatus (1.9 × 10-5 ng.algae-1) >C. vulgaris (1.4 × 10-5 ng.algae-1) >Mix (9.8 × 10-6 ng.algae-1) >R. subcapitata (2.8 × 10-6 ng.algae-1). The results suggest that initial algal population density is a determinant factor for efficient EtBr removal by microalgae species in short term treatments. In order to obtain 100% of EtBr removal, it should be necessary 1010, 1010 and 1011 algae.mL-1 of C. vulgaris, D. subspicatus and R. subcapitata, respectively. The results strongly suggest phycoremediation can be explored as an alternative method for EtBr removal.

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Abstract A feasibility analysis of tertiary treatment for Organic Liquid Agricultural Waste is presented using filamentous algae belonging to the genus Cladophora sp. as an alternative to chemical tertiary treatment. The main advantages of tertiary treatments that use biological systems are the low cost investment and the minimal dependence on environmental variables. In this work we demonstrate that filamentous algae reduces the nutrient load of nitrate (circa 75%) and phosphate (circa 86%) from the organic waste effluents coming from dairy farms after nine days of culture, with the added advantage being that after the treatment period, algae removal can be achieved by simple procedures. Currently, the organic wastewater is discarded into fields and local streams. However, the algae can acquire value as a by-product since it has various uses as compost, cellulose, and biogas. A disadvantage of this system is that clean water must be used to achieve enough water transparency to allow algae growth. Even so, the nutrient reduction system of the organic effluents proposed is friendly to the ecosystem, compared to tertiary treatments that use chemicals to precipitate and collect nutrients such as nitrates and phosphates.

Resumo Uma análise de viabilidade do tratamento terciário para Resíduos Agrícola Líquidos Orgânicos é apresentada usando algas filamentosas pertencentes ao gênero Cladophora sp. como alternativa ao tratamento químico terciário. Os tratamentos terciários que utilizam sistemas biológicos têm baixo custo de investimento e a dependência de variáveis ambientais é mínima. Neste trabalho, é demonstrado que essas algas filamentosas reduzem a carga nutricional de nitrato (circa 75%) e fosfato (circa 86%) dos efluentes de resíduos orgânicos provenientes de fazendas de leite em nove dias de cultura e tem a vantagem de que as algas podem ser facilmente coletadas posteriormente. Atualmente, as águas residuais orgânicas são descartadas nos campos e córregos locais. Posteriormente, as algas podem ser consideradas como matéria prima, uma vez que possuem várias utilidades como composto, celulose e biogás. Uma desvantagem desse sistema é que água limpa deve ser usada para obter transparência de água suficiente para permitir o crescimento de algas. Mesmo assim, o sistema de redução de nutrientes dos efluentes orgânicos propostos e amigável ao ecossistema, comparado aos tratamentos terciários que utilizam produtos químicos para precipitar e coletar nutrientes como nitratos e fosfatos.

RESUMO

Abstract A feasibility analysis of tertiary treatment for Organic Liquid Agricultural Waste is presented using filamentous algae belonging to the genus Cladophora sp. as an alternative to chemical tertiary treatment. The main advantages of tertiary treatments that use biological systems are the low cost investment and the minimal dependence on environmental variables. In this work we demonstrate that filamentous algae reduces the nutrient load of nitrate (circa 75%) and phosphate (circa 86%) from the organic waste effluents coming from dairy farms after nine days of culture, with the added advantage being that after the treatment period, algae removal can be achieved by simple procedures. Currently, the organic wastewater is discarded into fields and local streams. However, the algae can acquire value as a by-product since it has various uses as compost, cellulose, and biogas. A disadvantage of this system is that clean water must be used to achieve enough water transparency to allow algae growth. Even so, the nutrient reduction system of the organic effluents proposed is friendly to the ecosystem, compared to tertiary treatments that use chemicals to precipitate and collect nutrients such as nitrates and phosphates.

Resumo Uma análise de viabilidade do tratamento terciário para Resíduos Agrícola Líquidos Orgânicos é apresentada usando algas filamentosas pertencentes ao gênero Cladophora sp. como alternativa ao tratamento químico terciário. Os tratamentos terciários que utilizam sistemas biológicos têm baixo custo de investimento e a dependência de variáveis ambientais é mínima. Neste trabalho, é demonstrado que essas algas filamentosas reduzem a carga nutricional de nitrato (circa 75%) e fosfato (circa 86%) dos efluentes de resíduos orgânicos provenientes de fazendas de leite em nove dias de cultura e tem a vantagem de que as algas podem ser facilmente coletadas posteriormente. Atualmente, as águas residuais orgânicas são descartadas nos campos e córregos locais. Posteriormente, as algas podem ser consideradas como matéria prima, uma vez que possuem várias utilidades como composto, celulose e biogás. Uma desvantagem desse sistema é que água limpa deve ser usada para obter transparência de água suficiente para permitir o crescimento de algas. Mesmo assim, o sistema de redução de nutrientes dos efluentes orgânicos propostos e amigável ao ecossistema, comparado aos tratamentos terciários que utilizam produtos químicos para precipitar e coletar nutrientes como nitratos e fosfatos.