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Wetlands provide numerous ecosystem services to the environment, such as nutrient removal and storage. The aim of this work is to evaluate the nutrient dynamics in different sectors within wetland systems in the south of the Samborombón Bay (Argentina) based on hydrological and/or anthropogenic variations. For this purpose, the hydrological features of the wetland were defined through the analysis of satellite images, precipitation and tidal data, and field surveys. Three sectors were identified in the wetland: one with tidal influence, another which is dependent on rainfall, and another that receives inputs from rainfall and from a sewage effluent treatment plant. In order to analyze the nutrient dynamics, samples of surface water, groundwater, and sediments were collected from these sectors. Measurements of pH and electrical conductivity were determined in situ in water samples, while the concentration of inorganic forms of phosphorus and nitrogen, soluble reactive silica, and organic carbon were determined through laboratory analysis. Also, bioavailable phosphorus, organic matter, pH, and electrical conductivity were determined in the sediment samples collected. Statistical analysis of the data reveals differences between the sectors and allows the interpretation of the dynamics of the studied components in the wetland. Electrical conductivity distinguishes the intertidal sectors of the wetland while components associated with P and N discriminate the sectors with inputs from the sewage effluent treatment plant. On the other hand, soluble reactive silica, organic carbon, and organic matter do not seem to be influenced by the tide or effluent discharge. This study demonstrates that the studied wetland works as a nutrient retention area, providing ecosystem services to local inhabitants. Although these services can be utilized, they require a continuous monitoring over time to provide an early warning in case the variations in P and N cycles could lead to eutrophication or wetland degradation.

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Resumen Introducción: La industria acuícola está en constante crecimiento, registrando una producción mundial de casi 88 millones de toneladas para el año 2020. Esta industria trae consigo problemas ambientales si sus efluentes no son debidamente tratados. En el 2020, se constituyó la primera empresa de base tecnológica del CONICET en la Patagonia Argentina cuyo propósito es la producción acuícola del erizo verde de mar, Arbacia dufresnii con la finalidad de elaborar una gama de productos nutracéuticos. Su sistema de cultivo conlleva un compromiso de sustentabilidad desde su creación, y sin embargo genera efluentes con niveles altos de nitratos y fosfatos. Objetivo: Ante este escenario, y valorizando la biorremediación como herramienta de tratamiento de aguas, se propone en este trabajo la utilización de las microalgas marinas como agentes fitorremediadores del efluente acuícola. Métodos: Se utilizaron las microalgas Chaetoceros gracilis, Navicula sp., Tetraselmis suecica., Rhodomona salina., Nanochloropsis galvana y Cylindrotheca closterium, las cuales son usadas como alimento de las larvas del erizo en el proceso productivo. Se diseñó un experimento que compara el crecimiento microalgal y la capacidad de remoción de los nutrientes en el efluente en contraste con el medio de cultivo artificial actualmente usado en el ciclo productivo. Resultados: Es posible remediar el efluente de la industria acuícola mediante las microalgas seleccionadas, con porcentaje de eficacia de remoción del 100 % del nitrato y un porcentaje de eficacia de remoción promedio de 50 % para todas las microalgas testeadas. Asimismo, se obtuvieron valores de biomasa microalgal significativamente mayores cuando el cultivo fue realizado en el efluente respecto del cultivo en el medio artificial. Conclusiones: Los avances en investigación proporcionados en este trabajo ponen de manifiesto que es posible el aprovechamiento de un descarte para cultivar las microalgas, incluso mejorando la productividad microalgal para su uso como alimento, disminuyendo los costos involucrados en el sector de producción microalgal cambiando el uso del tipo de medio de cultivo actual (F/2) por el proveniente de un descarte. Estos avances si son escalados y validados, pueden mejorar los estándares de sustentabilidad de la industria en el marco de una economía circular.

Abstract Introduction: The aquaculture industry is constantly growing, registering a global production of almost 88 million tonnes by 2020. This industry brings environmental problems if its effluents are not properly treated. In 2020, the first technology-based company of CONICET was established in Argentine Patagonia whose purpose is the aquaculture production of the green sea urchin, Arbacia dufresnii to develop a range of nutraceutical products. Its cultivation system entails a commitment to sustainability since its creation, and yet it generates effluents with high levels of nitrates and phosphates. Objective: Given this scenario, and valuing bioremediation as a water treatment tool, the use of marine microalgae as phytoremediating agents of aquaculture effluent is proposed in this work. Methods: The microalgae Chaetoceros gracilis, Navicula sp., Tetraselmis suecica, Rhodomona salina, Nanochloropsis galvana and Cylindrotheca closterium were use; which are used as food for sea urchins larvae in the production process. An experiment was designed that compares the microalgal growth and the removal capacity of nutrients in the effluent in contrast to the artificial culture medium currently used in the production cycle. Results: It is possible to remedy the aquaculture industry's effluent by employing the selected microalgae, with a percentage of removal efficiency of 100 % of the nitrate and an average removal efficiency percentage of 50 % for all the microalgae tested. Likewise, significantly higher microalgal biomass values were obtained when the culture was carried out in the effluent the culture in the artificial environment. Conclusions: The advances in research provided in this work show that it is possible to take advantage of a discard to cultivate microalgae, even improving microalgal productivity for use as food, reducing the costs involved in the microalgal production sector by changing the use of the type of current culture medium (F/2) for that from a current discard. These advances, if scaled and validated, can improve industry sustainability standards within the framework of a circular economy.

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This review aims to perform an updated bibliographical survey on the cultivation of microalgae in domestic wastewater with a focus on biotechnological aspects. It was verified that the largest number of researches developed was about cultures in microalgae-bacteria consortium and mixed cultures of microalgae, followed by researches referring to the species Chlorella vulgaris and to the family Scenedesmaceae. According to published studies, these microorganisms are efficient in the biological treatment of domestic wastewater, as well as in the production of high value-added biomass, as they are capable of biosorbing the organic and inorganic compounds present in the culture medium, thus generating cells with high levels of lipids, proteins, and carbohydrates. These compounds are of great importance for different industry sectors, such as pharmaceuticals, food, and also for agriculture and aquaculture. In addition, biomolecules produced by microalgae can be extracted for several biotechnological applications; however, most studies focus on the production of biofuels, with biodiesel being the main one. There are also other emerging applications that still require more in-depth research, such as the use of biomass as a biofertilizer and biostimulant in the production of bioplastic. Therefore, it is concluded that the cultivation of microalgae in domestic wastewater is a sustainable way to promote effluent bioremediation and produce valuable biomass for the biobased industry, contributing to the development of technology for the green economy.

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The excessive consumption of plastic packaging, especially those produced with polyethylene terephthalate (PET), and the fact that most of them are destined for garbage have made such packaging a worrying environmental liability. Their inadequate disposal promotes the pollution of soils, watercourses, and oceans, and even the presence of component materials of these packages in the human body, in the form of microplastics, has been observed. As research in the area advances, greater concerns arise, as more problems arising from the excessive use and disposal of plastics are identified. Looking for an alternative for the destination of this material, a technology was developed for the production of materials with characteristics similar to 3D graphene. This carbon material has qualities and versatility that allow its wide use in several applications and is produced using PET as a carbon precursor. This work presents this production technology with possible variables, the characterization of the produced materials, and their potential applications. For the electronics area, such as supercapacitors, improvement points needed for validation were observed. For application as an adsorbent and use in the treatment of industrial effluents when using sand covered by carbon material, the results demonstrated efficiency. The material proved to be a potential destination for PET, as an alternative to reduce this environmental liability.

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In recent decades, hydrogels, as adsorption materials, have received important attention due to their characteristics and properties, such as mechanical strength, biocompatibility, biodegradability, swellability, and stimuli sensitivity. In the actual framework of sustainable development, it has been imperative to develop practical studies of hydrogels in the treatment of actual industrial effluents. Accordingly, the current work has, as its objective, to make evident hydrogels' applicability in the treatment of actual industrial effluents. For this purpose, a bibliometric analysis and systematic review based on the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) method were conducted. The relevant articles were selected from the Scopus and Web of Science databases. Some important findings were that: (1) China is the leading country when it comes to hydrogel application in actual industrial effluents, (2) the motor studies are focalized on the treatment of wastewater by hydrogels, (3) the fixed-bed columns are suitable unit equipment for the treatment of industrial effluents of using hydrogels, and (4) the hydrogels show excellent adsorption capacities of ion and dye contaminants present in industrial effluents. In summary, since the implementation of sustainable development in 2015, the progress of practical hydrogel applications in the treatment of industrial effluent has been receiving more attention, and the selected studies demonstrate the implementation viability of these materials.

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Fishing industries are characterized by high water consumption and a considerable content of organic matter and salt in their wastewater. In this work, a combined electrochemical process was studied at laboratory scale for the treatment of real wastewater from the processing of mackerel from an industrial facility located in the province of Buenos Aires that discharges to the sewer, which the plant is currently using and does not produce an effluent in discharge conditions. Taking advantage of the high conductivity of these effluents, in the electrocoagulation stage with aluminum anodes, it was possible to remove the coarsest fraction of suspended matter, achieving a Chemical Oxygen Demand (COD) removal of about 60%, at pH 7.5, showing a higher efficiency over the conventional treatment. Despite this superiority, the necessary removal was still not achieved; therefore, the wastewater treated by electrocoagulation was then subjected to electrooxidation, using a graphite anode and a titanium cathode, and with a first-order oxidation kinetics, achieving a final COD value lower than the discharge limit, after 7.5 min of processing at pH 6, obtaining an efficient treatment for removal of high concentrations dissolved organic matter and colloidal/suspended particles in this kind of effluent. All treatments were performed in batches. The removal of pollutants in the wastewater was verified by means of spectroscopic and voltammetric techniques; at the same time, these techniques, together with SEM-EDX analysis, proved the superiority of electrocoagulation over chemical coagulation. This study laid the groundwork for the design of modifications to the plant to achieve discharge parameters in accordance with current legislation.

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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. The biomass was applied dry and as a mixture to demonstrate its potential to increase plant production and soil metabolic functions, analyzed short-term. Doses of 0.25%, 0.5%, 1%, and 2% biomass were applied in soils from (i) Horizon A: taken at a depth between 0 and 10 cm and; (ii) Horizon B: taken at a depth between 20 and 40 cm. Corn growth (Zea Mays L.), basal soil respiration, microbial biomass carbon, total organic carbon, ß-glucosidase, acid phosphatase, arylsulfatase, and urease enzymatic activity were evaluated in each sample. It is concluded that applying 2% microalgae biomass led to higher basal soil respiration, microbial biomass carbon, and ß-glucosidase, acid phosphatase, arylsulfatase enzymatic activity in both soils. On the other hand, boron may have contributed to urease activity reduction in Soil A. Although 2% biomass led to higher soils characteristics, that dose did not promote higher plant growth. Hence, considering that plant growth must be in line with changes in soil characteristics, the result that provided the higher plant shoot dry matter mass was by applying 0.55% biomass in both soils. Therefore, the application of microalgae biomass produced from a meat processing industry effluent treatment promoted a biologically active soil and boosted plant growth.

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Pulp and paper industries are very important for developing the Brazilian economy. During production processes, many effluents are generated with high polluting potential. The objective of this study is to conduct an extensive literature review on the characteristics of effluents and treatment forms adopted by Brazilian mills in this industrial sector. Most consulted studies address raw (without treatment) and secondary (after biological treatment) effluents, considering their main characteristics like pH, chemical and biochemical oxygen demands (COD and BOD, respectively), color, solids, organochlorines, toxicity, estrogenic activity, and phenols. Raw effluents differ considerably in composition, depending on the type of paper produced, the pulping process employed, and other steps, like pulp bleaching. Raw effluent characteristics indicate that this effluent cannot be directly disposed of into water bodies, because it does not comply with federal and state disposal standards. Secondary effluents normally comply with Brazilian legislations, although some studies have reported COD and total phenol concentrations higher than disposal standards, suggesting that additional treatments are necessary. Treated effluent reuse was verified in some Brazilian mills, while its disposal in eucalyptus plantations has been considered a promising alternative for irrigation purposes.

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Enzyme immobilization is an important alternative to stabilize enzyme properties favoring the efficiency of derivatives (enzyme + support/matrix) for different purposes. According to this, the current study aimed to immobilize the Aspergillus fumigatus CAS21 tannase and the use of the derivatives in the treatment of the effluent produced by the tannery industry. The tannase was immobilized on sodium alginate, DEAE-Sephadex, amberlite, and glass pearls as supports. Calcium alginate was the most adequate support for tannase immobilization with 100% yield and 94.3% for both efficiency and activity. The best tannase activity for the calcium alginate derivative was obtained at 50°C-60°C and pH 5.0. Thermal and pH stabilities evaluated for 24 h at 30°C-60°C and pH 4-7, respectively, were improved if compared to the stability of the free enzyme. Considering the reuse of the calcium alginate derivative, 78% of the initial activity was preserved after 10 catalytic cycles, and after the 9-month storage at 4°C, the activity was maintained in 70%. This derivative was applied in a packed bed reactor (PBR) for the treatment of tannin-rich effluents from the tannery industry. The reduction of the tannin content was effective reaching degradation of 74-78% after 48 h of PBR operation. The concentration of total phenolic compounds was also reduced, and the color and clarity of the effluent improved. In conclusion, the calcium alginate derivative is an attractive alternative as biocatalyst for large-scale treatment of the effluents from the tannery industry.

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This work investigated the efficiency of bioremediation of heavy fuel oil (HFO) in aqueous solutions by living Eichhornia crassipes (Mart.) Solms, also known as water hyacinth. Possibility of using post-biosorption macrophytes to produce briquettes was also studied. HFO was characterized by its density, viscosity, and Fourier-transform infrared spectroscopy. Water hyacinth was characterized by scanning electron microscope, pH of zero point of charge, buoyancy, and wettability. Experiments were performed to evaluate effects of contact time and initial oil concentration on biosorption. E. crassipes presented a hydrophobic nature, ideal for the treatment of oily effluents. Hollow structures in macrophytes were also identified, which favor capillary rise and retention of oils of high density and viscosity. Biosorption efficiency of HFO reached 94.8% in tests with initial concentration of 160 mg.L-1. A calorific value of 4022 kcal.kg-1 was obtained in briquettes made of water hyacinth post-biosorption. These results reinforce the great potential of E. crassipes as a sustainable and efficient alternative for treatment of oily effluents.

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This study reports the preparation of TiO2 and CeO2 doped with different quantities of terbium and discusses the influence of this dopant on the photocatalytic activity of the semiconductors, with respect to the degradation of methylene blue, under ultraviolet and solar radiations. The oxides obtained were characterized by X-ray diffraction, infrared vibrational spectroscopy, diffuse reflectance spectroscopy, scanning electron microscopy, and dispersive energy spectroscopy. The results indicate that the presence of the dopant in TiO2 favored the formation of the anatase crystalline phase to the detriment of rutile, increased the band gap energy, and decreased the size of the nanoparticles. Doping CeO2 with Tb resulted in a fluorite-type crystalline structure, reduced band gap, and smaller particle size. The photocatalytic activity decreases as the concentration of terbium increases regardless of the radiation source and nature of the oxide. Furthermore, a better performance was observed for all semiconductors excited by solar radiation in comparison to ultraviolet light. The samples of pure TiO2 and TiO2 doped with 0.5 and 1% terbium showed total removal of the dye after less than 120 min of reaction, while the samples of pure CeO2 and CeO2 doped with 0.5% terbium showed approximately 80% and 57% of dye removal after 120 min, suggesting that these materials can be promising for the treatment of industrial effluents.

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Many industries generate a considerable amount of wastewater containing toxic and recalcitrant dyes. The main objective of this research was to examine the biosorption capacity of Reactive Blue 19 and Reactive Red 141 by the Antarctic yeast Debaryomyces hansenii F39A biomass. Some variables, including pH, dye concentration, amount of adsorbent and contact time, were studied. The equilibrium sorption capacity of the biomass increased with increasing initial dye concentration up to 350mg/l. Experimental isotherms fit the Langmuir model and the maximum uptake capacity (qmax) for the selected dyes was in the range of 0.0676-0.169mmol/g biomass. At an initial dye concentration of 100mg/l, 2g/l biomass loading and 20±1°C, D. hansenii F39A adsorbed around 90% of Reactive Red 141 and 50% of Reactive Blue 19 at pH 6.0. When biomass loading was increased (6g/l), the uptake reached up to 90% for Reactive Blue 19. The dye uptake process followed a pseudo-second-order kinetics for each dye system. As seen throughout this research study, D. hansenii has the potential to efficiently and effectively remove dyes in a biosorption process and may be an alternative to other costly materials.

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Diante das estratégias de ensino e aprendizagem adotadas na disciplina de Anatomia da Escola de Enfermagem de Ribeirão Preto da Universidade de São Paulo (EERP/USP), que requer a conservação de peças cadavéricas em solução de formol, no Laboratório Multidisciplinar são gerados significantes volumes de efluentes contendo este composto. Considerando as características tóxicas dessa substância, tanto aos seres vivos quanto ao meio ambiente, torna-se imprescindível o gerenciamento e tratamento deste resíduo gerado antes do descarte na rede coletora de esgotos. Embora diferentes métodos, sejam eles químicos ou biológicos, possam ser utilizados para promover o tratamento prévio ao descarte de soluções contendo formol, o uso de tratamentos biológicos, como o reator anaeróbio, possibilita o tratamento de grandes volumes de resíduos, gera menor exposição ocupacional e possui reduzido custo do processo. No ano de 2017 a EERP/USP implementou o Reator Anaeróbio Horizontal de Leito Fixo (RAHLF), dimensionado para atender grandes volumes de efluentes com solução de formol gerados na unidade. Neste contexto, este estudo inédito em escala industrial, além de monitorar a eficiência da remoção da solução de formol dos efluentes gerados do sistema de biorreatores também caracterizamos os pontos críticos de controle do processo de tratamento do RAHLF, durante o período de fevereiro a junho e de setembro a novembro do ano de 2020. Os resultados na entrada do RAHLF apresentaram uma média de 480,19 ± 116,06 mg.L-1, com amplitude amostral de 238,37 mg.L-1 a 774,60 mg.L-1, já na saída do RAHLF demonstraram média de 1,39 ± 0,56 mg.L-1, com amplitude amostral de 0,04 mg.L-1 a 2,32 mg.L-1, evidenciando assim a eficiência na degradação do formol pelos biorreatores em média de 99,70%. A partir dos dados foi evidenciado que além do desempenho satisfatório do RAHLF para o pré-tratamento de água residuária contendo formol, o reator também apresentou estabilidade de operação durante o desenvolvimento do estudo. Com o conhecimento de todas as etapas e dos pontos críticos do processo foi possível a organização do fluxograma do processo, desde o local gerador até a disposição do efluente para a rede coletora de esgoto municipal. A partir do fluxograma, foi possível desenvolver protocolo de operação, visando minimizar ao máximo potenciais ocorrências de falhas durante o processo. Este estudo gerou conhecimento que contribui para melhor compreensão da biotecnologia anaeróbia implantada para alcançar a degradação da solução de formol no efluente do Laboratório Multidisciplinar da EERP/USP. A implantação e funcionamento adequado do biodigestor refletem o compromisso socioambiental da universidade com a sociedade e com o meio ambiente, na busca de ações que promovam tanto a saúde pública quanto a sustentabilidade ambiental. Os resultados constituirão também uma base de dados para outros gestores de biodigestores implantados na universidade, sendo de grande importância para a continuidade de investigações relacionadas com o tratamento dos efluentes em laboratórios de ensino

For the development of teaching and learning strategies adopted in the discipline of Anatomy at the University of São Paulo at College of Nursing in Ribeirão Preto (CNRP/USP), which requires the preservation of cadaveric parts in a formaldehyde solution, the Multidisciplinary Laboratory generates significant volumes of effluents containing this compound. Considering the toxic characteristics of this substance, both to living beings and to the environment, it is essential to manage and treat this wastewater before its disposal in the sewage collection system. Although different methods, whether chemical or biological, can be used to promote treatment prior to disposal of solutions containing formaldehyde, the use of biological treatments, such as the anaerobic reactor, allows the treatment of large volumes of waste, generates less occupational exposure and has reduced process cost. In 2017, EERP/USP implemented the Anaerobic Horizontal Fixed Bed Reactor (AHFBR), dimensioned to supply large volumes of wastewater with a formaldehyde solution generated at the unit. In this context, this unprecedented study on an industrial scale, in addition to monitoring the efficiency of the removal of the formaldehyde solution from the effluents generated from the bioreactor system, we also characterized the critical control points of the AHFBR treatment process, during the period from February to June and from September to November of 2020. The results of the affluent of the AHFBR presented an average of 480.19 ± 116.06 mg.L-1, with a sample range of 238.37 mg.L-1 to 774.60 mg. L-1, already in the effluent of the AHFBR obtained average of 1.39 ± 0.56 mg.L-1, with a sample range of 0.04 mg.L-1 to 2.32 mg.L-1, thus evidencing the efficiency in formaldehyde degradation by bioreactors on average of 99.70%. From the data, it evidenced that in addition to the satisfactory performance of the AHFBR for the pre-treatment of wastewater containing formaldehyde, the reactor also showed operating stability during the development of the study. With the knowledge of all the steps and critical points of the process, it was possible to organize the process flowchart, from the generating site to the disposal of the effluent to the municipal sewage collection network. From the flowchart, it was possible to develop an operation protocol, aiming to minimize as many potential occurrences of failures during the process as possible. This study generated knowledge that contributes to a better understanding of the anaerobic biotechnology implemented to achieve the degradation of the formaldehyde solution in the effluent of the Multidisciplinary Laboratory at CNRP/USP. The implantation and proper functioning of the biodigester reflect the university's socio-environmental commitment to society and the environment, in the search for actions that promote both public health and environmental sustainability. The results will also constitute a database for other managers of biodigesters implemented at the university, being of great importance for the continuity of investigations related to the treatment of effluents in teaching laboratories

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Flocculants and coagulants market is expected to grow in a Compound Annual Growth Rate (CAGR) of 5.9% between 2017 and 2022. The development of non-pollutant coagulants/flocculants aiming to replace conventional ones, usually toxic, has been extensively studied and one alternative is the possibility of obtaining tannin-based flocculants, compounds present in many plants and easily extracted. However, in order to use tannins as flocculants, their cationization is necessary, which is normally accomplished by Mannich reaction that requires formaldehyde addition, a toxic compound. In order to fill a gap in the literature, regarding coagulants/flocculants synthesis through green procedures, this paper aims to synthesize a flocculant from tannins with no use of formaldehyde, and optimize this synthesis through a Central Composite Rotatable Design (CCRD). The optimization variables were ammonium hydroxide (NH4OH) to tannin ratio, in the range of 1:1 to 5:1, and reaction time, in the range of 1 to 4 h The evaluation of the synthesized flocculant samples was accomplished by jar tests using a simulated effluent containing humic acid and the effect of reactant ratio and reaction time used in the synthesis was assessed. The flocculant synthesis methodology proposed on this study showed excellent results regarding turbidity and color removal, since 100% of turbidity removal and 89.9% of color removal were achieved. This novel tannin-based flocculant synthesis methodology is a promising technology to replace conventional coagulants/flocculants, once it is environmentally friendly.

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Liquid effluents from various dyeing industries often have a high concentration of dyes that diffuse into river systems and can be toxic and non-degradable in the environment. In this study, the potential of the use of timbaúva seed husks in the preparation of four adsorbents tested in the removal of methylene blue was analyzed: in natura, chemically activated material (qmax = 1.24 ± 0.04 mg g-1), carbonized (qmax = 1.96 ± 0.03 mg g-1), and activated carbon (qmax = 1.983 ± 0.04 mg g-1). The adsorbents were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and CHN elemental analysis to assist in the proposed dye adsorption mechanism in the adsorbents tested. In the adjustment of the kinetic parameters, the pseudo-second order model was predominant by the statistical analysis of the ARE and R2. The carbonized samples were better adjusted to Langmuir isotherms. The removal efficiency of the methylene blue dye in aqueous solutions at the concentrations and conditions studied was 86.78%. The coal from the seed husks of timbaúva has shown excellent performance in adsorption of the methylene blue dye and, therefore, can have technological application.

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Two chromium removal experiments were performed in bioreactors with and without a magnetic field under the same conditions. The release of the chromium present in the biomass was tested in two experiments one with the initial pH of the medium and one with pH 4.0. The objective was to remove Cr(VI) and total Cr from the effluent, this was carried out by placing biological treatments of synthetic effluent contaminated with 100 mg/L of Cr(VI) in a bioreactor with neodymium magnets that applied a magnetic field (intensity 85.4 mT) to the mixed culture. The removal of Cr(VI) was approximately 100.0% for the bioreactor with a magnetic field and 93.3% for the bioreactor without a magnetic field for 9 hr of recirculation of the synthetic effluent by the bioreactor. The removal of total Cr was 61.6% and 48.4%, with and without a magnetic field, respectively, for 24 hr. The desorption of Cr(VI) in the synthetic effluent was 0.05 mg/L, which is below the limit established by Brazilian legislation (0.1 mg/L) for the discharge of effluent containing Cr(VI) into bodies of water. The results obtained for the removal of chromium in synthetic effluent suggested that there was no significant influence on the viable cell count of the mixed culture. The desorption of Cr(VI) in synthetic effluent after bioadsorption of chromium by the mixed culture in the process of removal of chromium in bioreactors with and without a magnetic field was not significant in either of the experiments with different initial pHs.

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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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RESUMO Este trabalho realizou uma revisão integrativa de artigos científicos indexados entre 2007 e 2017 em diferentes bases de dados sobre o tratamento e o reúso de efluentes provenientes da indústria de antibióticos. Foram encontrados 31 artigos, sendo que somente 4 abordaram o reúso de efluente, e 1 utilizou um sistema de tratamento em escala real. A maior parte desses estudos foi realizado na Ásia, com destaque para a China. Observa-se que, no Brasil, que é um dos grandes produtores e consumidores de fármacos do mundo, esse tipo de pesquisa ainda é incipiente. Os processos mais encontrados foram os oxidativos avançados que mostraram maior eficiência na remoção de antibióticos, mas podem gerar subprodutos, o que pode representar um risco ainda maior dependendo da substância formada. Os processos biológicos devem ser primeiramente aclimatados aos antibióticos para não serem impactados, entretanto, a liberação desses micro-organismos resistentes no corpo receptor também apresenta um risco ambiental. Os sistemas integrados de membranas ao biológico também foram bem eficientes, mas atenta-se ao risco na destinação final dessas membranas que foram capazes de reter esses compostos. No geral, são necessários mais estudos sobre essa abordagem para reduzir os riscos no desenvolvimento de micro-organismos multirresistentes no meio ambiente.

ABSTRACT This work carried out an integrative review of scientific articles indexed between 2007 and 2017 in different databases on treatment and reuse of effluents from the antibiotic industry. Thirty-one articles were found and only four addressed effluent reuse, and one used a full-scale treatment system. Most of these studies were conducted in Asia, with emphasis on China. In Brazil, which is one of the largest producers and consumers of drugs in the world, this type of research is still incipient. The most commonly found processes were oxidative advanced processes that showed greater efficiency in removing antibiotics, but may generate by-products, which might pose an even greater risk depending on the substance formed. Biological processes must first be acclimated to antibiotics in order not to be impacted, however, the release of these resistant microorganisms into the water bodies also presents an environmental risk. Biological integrated membrane systems were also very efficient, but attention should be given to the risk in the final destination of these membranes that were able to retain those compounds. Overall, further studies on this approach are needed to reduce the risks of developing multi-resistant microorganisms in the environment.

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RESUMO O objetivo deste trabalho foi avaliar o tratamento de efluentes de lavanderia hospitalar por processo oxidativo avançado UV/H2O2. O planejamento fatorial 32 foi empregado de modo a avaliar a influência do pH e da dosagem de peróxido na eficiência do tratamento. Os experimentos de foto-oxidação foram realizados com efluentes coletados na lavanderia do Hospital Universitário Regional de Maringá (HUM). Resultados relativos à caracterização do efluente e às reduções de parâmetros físico-químicos: cor, turbidez, demanda biológica de oxigênio (DBO), surfactantes e a quantificação de coliformes totais e termotolerantes, também são apresentados neste trabalho. Foram testados três valores de pH - 5, 7 e 9 - e três dosagens de peróxido de hidrogênio nas razões de [DQO]:[H2O2] - 1:0,5, 1:2,5 e 1:5. Os melhores resultados foram alcançados com o tratamento realizado em pH 9 e razão [DQO]:[H2O2] de 1:2,5. As eficiências de remoção da demanda química de oxigênio (DQO) e de surfactantes foram, em média, de 60,3 e 98%, respectivamente, porém o tratamento não se mostrou eficiente na redução de cor e turbidez, demonstrando a necessidade de se acoplar tratamentos complementares para a redução de tais parâmetros.

ABSTRACT The objective of this work was to evaluate the treatment of hospital laundry effluents by advanced oxidation process UV/H2O2. Factorial design 32 was employed to investigate the influence of pH and peroxide dosage on treatment efficiency. The photo-oxidation experiments were performed with effluents collected in the laundry of the Regional University Hospital of Maringá (HUM). Physicochemical parameters of effluent color, turbidity, BOD, surfactants and quantification of total and thermotolerant coliforms are presented in this study. Three values ​​of pH - 5, 7 and 9 - and three dosages of hydrogen peroxide with [COD]:[H2O2] ratios of 1:0.5, 1:2.5 and 1:5 (w:w) were tested. The best results were achieved with the treatment performed at pH 9 and ratio [COD]:[H2O2] of 1:2.5. The average removal efficiencies of COD and surfactants were 60.3 and 98%, respectively. However, the treatment was not efficient in reducing color and turbidity, demonstrating the need to combine complementary treatments for the reduction of such parameters.

RESUMO

Abstract Wastewater generated in tanneries have essential elements for microalgae growth, but it has also some toxic compounds that may hinder or restrain the growth of microalgae in this environment. This work tested microalgae consortium growth originating from a deactivated effluent treatment decanter of a complete tannery (beamhouse to finished leather) for the treatment of wastewater of a tannery processing wet-blue leather to finished leather. It was initially evaluated the growth of the microalgae consortium in the three effluents diluted in 50% distilled water: raw effluent (50RE50W), effluent after primary coagulation/flocculation (50PE50W), and effluent after primary and secondary biological treatment (50BE50W). After 16 days of cultivation, the 50PE50W presented the highest biomass concentration (1.77 g L−1). The highest removal values for effluents 50RE50W, 50PE50W and 50BE50W were 51.02%, 99.90%, 82.88%, and 91.75% for chemical oxygen demand (COD), N-NH3, TKN, and P-PO4-, respectively. It was verified low levels of nutrient removal in the raw effluent (100RE), since the consortium was not able to grow in this medium. Finally, at concentrations of 25RE75BE (25% raw effluent diluted with 75% effluent after the biological treatment) and 50RE50B (50% raw effluent diluted with 50% effluent after the biological treatment), effective removal values were reached. Biomass growth concentration up to 1.3 g L-1 and removal values for N-NH3, TKN, P-PO4, COD, total organic carbon (TOC) and biological oxygen demand (BOD5), of 99.90%, 79.36%, 87.82%, 14.26%, 35.82%, and 42.86%, respectively, were reached in 50RE50B.

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