Search

This work presents a bibliographic review of the literature regarding the simultaneous removal of contaminants of emerging concern (CECs) and disinfection in domestic wastewater matrices. These two responses are usually evaluated independently, as most attention has been centered on the discussion over the removal of CECs in the last 10 years. However, the simultaneous removal of CECs and pathogens from wastewater has been recently brought to the spotlight, especially considering the removal of antibiotics and antibiotic-resistant bacteria. Aiming at a reproducible and nonbiased methodology, a combination of the construction of a bibliometric portfolio with systemic analysis was performed with peer-reviewed manuscripts published between 2008 and 2019 in five distinct databases. Several keyword combinations were necessary to achieve a relevant portfolio according to strict criteria. As a result, five highly cited papers and authors were selected. Among the advanced oxidation processes (AOPs) explored for simultaneous removal of CECs and disinfection in these papers, detailed results have been elucidated mainly for ozonation. Thus, revealing the broad range of questions that have yet to be investigated in depth for new technologies such as irradiated solar processes. In addition, there is a lack of information associated with simultaneous assessment of CEC removal and disinfection in real samples and in wastewater matrices originated from different secondary treatment technologies in diverse locations.

This work investigated an innovative alternative to improve municipal wastewater treatment plant effluent (MWWTP effluent) quality aiming at the removal of contaminants of emerging concern (caffeine, carbendazim, and losartan potassium), and antibiotic-resistant bacteria (ARB), as well as disinfection (E. coli). Persulfate was used as an alternative oxidant in the solar photo-Fenton process (solar/Fe/S2O82−) due to its greater stability in the presence of matrix components. The efficiency of solar/Fe/S2O82− at neutral pH using intermittent iron additions is unprecedented in the literature. At first, solar/Fe/S2O82− was performed in a solar simulator (30 W m−2) leading to more than 60% removal of CECs, and the intermittent iron addition strategy was proved effective. Then, solar/Fe/S2O82− and solar/Fe/H2O2 were compared in semi-pilot scale in a raceway pond reactor (RPR) and a cost analysis was performed. Solar/Fe/S2O82− showed higher efficiencies of removal of target CECs (55%), E. coli (3 log units), and ARB (3 to 4 log units) within 1.9 kJ L−1 of accumulated irradiation compared to solar/Fe/H2O2 (CECs, 49%; E. coli, 2 log units; ARB, 1 to 3 log units in 2.5 kJ L−1). None of the treatments generated acute toxicity upon Allivibrio fischeri. Lower total cost was obtained using S2O82− (0.6 € m−3) compared to H2O2 (1.2 € m−3). Therefore, the iron intermittent addition aligned to the use of persulfate is suitable for MWWTP effluent quality improvement at neutral pH.

The current work presents new and versatile photocatalytic surfaces designed to remove contaminants of emerging concerns (CECs) from water. Photocatalytic thin films of titanium dioxide (TiO2) were deposited on a polyethylene terephthalate (PET) surface (PET-TiO2) and photosensitized by a natural and non-hazardous curcumin (turmeric). The TiO2 thin film was deposited in a single stage and solvent-free process, without thermal post treatment, using the high power impulse magnetron sputtering (HiPIMS) technique. The photocatalytic film was characterized by different techniques (SEM/EDS, STEM, AFM, UV–Vis spectroscopy, and wettability via water droplet contact angle). The photocatalytic activity was assessed by the degradation of two model CECs: the fungicide carbendazim (CBZ), used in different crops around the world (coffee, rice, fruits, etc.), and the anthropogenic pollution tracer caffeine (CAF). Removal of these model CECs of up to 39% were achieved under combined UV and visible irradiation under 7 h photocatalytic treatments. The degradation process was further studied by dissolved organic carbon analysis, with up to 80% removal, and acute ecotoxicity tests with Aliivibrio fischeri, indicating reduction of toxicity or non-change. The PET-TiO2 surfaces remained stable for 5 consecutive cycles of use, with similar kinetic rates. Finally, the species involved in photocatalytic reactions were investigated by the use of h+, HO and O2− trapping agents, both in the presence and absence of turmeric. The results indicated that the addition of the turmeric led to an increase in photogenerated O2− radicals due to a synergistic effect between the photocatalyst and photosensitizer. The results demonstrate the potential of the PET-TiO2 surfaces as a straightforward solution for the removal of CECs from waters, using a flexible, scalable, reusable and environmental friendly photocatalytic material.

The application of solar photo-Fenton as post-treatment of municipal secondary effluents (MSE) in developing tropical countries is the main topic of this review. Alternative technologies such as stabilization ponds and upflow anaerobic sludge blanket (UASB) are vastly applied in these countries. However, data related to the application of solar photo-Fenton to improve the quality of effluents from UASB systems are scarce. This review gathered main achievements and limitations associated to the application of solar photo-Fenton at neutral pH and at pilot scale to analyze possible challenges associated to its application as post-treatment of MSE generated by alternative treatments. To this end, the literature review considered studies published in the last decade focusing on CECs removal, toxicity reduction and disinfection via solar photo-Fenton. Physicochemical characteristics of effluents originated after UASB systems alone and followed by a biological post-treatment show significant difference when compared with effluents from conventional activated sludge (CAS) systems. Results obtained for solar photo-Fenton as post-treatment of MSE in developed countries indicate that remaining organic matter and alkalinity present in UASB effluents may pose challenges to the performance of solar advanced oxidation processes (AOPs). This drawback could result in a more toxic effluent. The use of chelating agents such as Fe

This work presents data regarding the occurrence and treatment of Contaminants of Emerging Concern (CECs) in Brazil in the past decade. The literature review (2011-2021) revealed the detection of 87 pharmaceutical drugs and personal care products, 58 pesticides, 8 hormones, 2 illicit drugs, caffeine and bisphenol A in distinct matrices (i.e.: wastewater, groundwater, sea water, rainwater, surface water, drinking water and hospital effluent). Concentrations of CECs varied from ng-μg L

The goal of this work was to evaluate the performance of the LED irradiated photo-Fenton process on the removal of (i) estrogenic activity and (ii) seven endocrine disruptors (EDs) (4-octylphenol, 4-nonylphenol, bisphenol A, estrone, 17β-estradiol, 17α-ethinylestradiol, and estriol) from real wastewater treatment plant effluent (WWTPE). EDs are a group of contaminants of emerging concern present in WWTPE and which may be recognized by hormone receptors, thus harming animal and human health. The yeast estrogenic screen test (YES) was used to quantify estrogenic activity promoted by EDs in WWTPE samples before and after photo-Fenton treatment. Tests were performed following a factorial design with different iron (20, 40, and 60 mg L−1) and hydrogen peroxide (100, 200, and 300 mg L−1) concentrations in a laboratory scale LED photoreactor (λ = 455 nm, 1.5 L, 1.6 × 10−6 Einstein s−1). EDs were analyzed by gas chromatography coupled to a mass spectrometer. Control experiments consisted of Fenton process, iron only, LED irradiation only, and H2O2 only. Optimum experimental conditions for LED photo-Fenton resulted in 62% removal of estrogenic activity and 59% mineralization. In addition, treated WWTPE was not toxic to Aliivibrio fischeri and more than 80% of EDs were removed during LED irradiated photo-Fenton. Although Fenton process showed similar efficiency to that obtained by LED photo-Fenton, a higher volume of sludge was generated in the dark. Finally, results obtained in this study confirm the applicability of LED irradiated photo-Fenton process for improving the quality of WWTPE as an alternative to solar photo-Fenton in case solar radiation is not available, thus reducing hazards associated to WWTPE reuse or discharge.

This work presents a bibliographic review of the literature regarding the simultaneous removal of contaminants of emerging concern (CECs) and disinfection in domestic wastewater matrices. These two responses are usually evaluated independently, as most attention has been centered on the discussion over the removal of CECs in the last 10 years. However, the simultaneous removal of CECs and pathogens from wastewater has been recently brought to the spotlight, especially considering the removal of antibiotics and antibiotic-resistant bacteria. Aiming at a reproducible and nonbiased methodology, a combination of the construction of a bibliometric portfolio with systemic analysis was performed with peer-reviewed manuscripts published between 2008 and 2019 in five distinct databases. Several keyword combinations were necessary to achieve a relevant portfolio according to strict criteria. As a result, five highly cited papers and authors were selected. Among the advanced oxidation processes (AOPs) explored for simultaneous removal of CECs and disinfection in these papers, detailed results have been elucidated mainly for ozonation. Thus, revealing the broad range of questions that have yet to be investigated in depth for new technologies such as irradiated solar processes. In addition, there is a lack of information associated with simultaneous assessment of CEC removal and disinfection in real samples and in wastewater matrices originated from different secondary treatment technologies in diverse locations.

The aim of this work is to evaluate the application of a steel waste, basic oxygen furnace sludge (BOFS), rich in iron, to treat water contaminated with elevated arsenic and sulfate concentrations. In the first step, three doses (10, 60, and 80 g L−1) of BOFS were tested to investigate the removal of As(III) and As(V) (67 mg L−1) and sulfate (3700 mg L−1) separately from an aqueous solution. In the second step, the efficacies of BOFS (10 g L−1) and commercial ZVI (5 g L−1) were compared to simultaneously remove arsenic and sulfate. The pH of the feed solution was adjusted to 2.5 and monitored during the experiment. The use of BOFS achieved arsenic removal up to 92% and sulfate removal of nearly 40% after 72 h of contact time. Use of BOFS also increased the solution pH to 12. Similar removal levels were achieved with both BOFS and ZVI. These results confirm the potential application of BOFS to remove high arsenic and sulfate concentrations from acidic solutions. The data obtained here should be used as a basis for further studies on the remediation of acid mine drainage with high concentrations of arsenic and sulfate using an abundant and low-cost steel waste.

A range of different studies has been performed in order to design and develop photocatalysts that work efficiently under visible (and near-infrared) irradiation as well as to improve photons absorption with improved reactor design. While there is consensus on the importance of photocatalysis for environmental applications and the necessity to utilized solar irradiation (or visible-light) as driving force for these processes, it is not yet clear how to get there. Discussion on the future steps towards visible-light photocatalysis for environmental application is of great interest to scientific and industrial communities and the present paper reviews and discusses the two main approaches, band-gap engineering for efficient solar-activated catalysts and reactor designs for improved photons absorption. Common misconceptions and drawbacks of each technology are also examined together with insights for future progress.

In the present study, a multistage route is proposed for the treatment of biodiesel industry wastewater (BWW) containing around 1000 mg L−1 of total organic carbon (TOC), 3500 mg L−1 of chemical oxygen demand (COD), and 1325 mg L−1 of oil and grease. Initially, BWW aerobic biodegradability was assessed via Zhan-Wellens biodegradability test to confirm the appropriate treatment route. Then, a hybrid moving bed bioreactor (MBBR) system was chosen as the first treatment stage. The hybrid MBBR achieved 69 and 68% removal of COD and TOC removals, respectively, and provided great conditions for biomass growth. The bacterial community present in the hybrid MBBR was investigated by PCR-DGGE and potential biodegraders were identified such as: members of Desulfuromonadales, Nocardioidaceae and Pseudomonadaceae. Since biodegradation in the hybrid MBBR alone was unable to meet quality requirements, advanced oxidation processes, such as Fenton and photo-Fenton, were optimized for application as additional treatment stages. Physicochemical properties and acute toxicity of BWW were analyzed after the multistage routes: hybrid MBBR + Fenton, hybrid MBBR + photo-Fenton and hybrid MBBR + UV-C254nm/H2O2. Hybrid MBBR + Fenton or photo-Fenton showed overall COD removal efficiencies greater than 95% and removed acute toxicity, thus being appropriate integrated routes for the treatment of real BWW.

Ethylenethiourea (ETU) is a toxic degradation product of one class of fungicide which is largely employed in the world, the ethylenebisdithiocarbamates. In this study, ETU was degraded by ozonation enhanced by UV-C light irradiation (O3/UV-C) in aqueous medium. Degradation experiments were conducted at natural pH (6.8) and neutral pH (7.0, buffered). ETU was promptly eliminated from the reactive medium during ozonation in the presence and absence of light. Within the first few minutes of reaction conducted in natural pH, the pH decreased quickly from 6.8 to 3.0. Results show that ETU mineralization occurs only in the reaction conducted in neutral pH and that it takes place in a higher rate when enhanced by UV-C irradiation. Main intermediates formed during the O3/UV-C experiments in different conditions tested were also investigated and three different degradation mechanisms were proposed considering the occurrence of direct and indirect ozone reactions. At pH 7, ethylene urea (EU) was quickly generated and degraded. Meanwhile, at natural pH, besides EU, other compounds originated from the electrophilic attack of ozone to the sulfur atom present in the contaminant molecule were also identified during reaction and EU was detected within 60 min of reaction. Results showed that ozonation enhanced by UV-C promotes a faster reaction than the same system in the absence of light, and investigation of the toxicity is recommended.

In this study, the steel manufacturing waste Basic Oxygen Furnace Sludge (BOFS) was tested as permeable reactive material for the remediation of soil contaminated with chromium. The material presents a high content of elemental iron and iron oxides typical of the steel manufacturing process. Here we propose a scheme of the chemical reactions responsible for remediation process including BOFS dissolution, Cr(VI) reduction and Cr(III) precipitation. Batch reactors showed that Cr(VI) removal increases as the pH decreases. Column tests demonstrated that the simulated PRB with BOFS as the reactive media was quite effective for removing Cr(VI) from groundwater, with a sorption capability of 0.213 mg Cr per gram of BOFS at an initial Cr(VI) concentration of 50 mg L−1 at pH 5.5. A long-term test lasting 71 days confirmed the proposed mechanisms and the suitability of using BOFS in a permeable reactive barrier.

This study aimed at investigating the degradation of fungicide carbendazim (CBZ) via photo-Fenton reactions in artificially and solar irradiated photoreactors at laboratory scale and in a semi-pilot scale Raceway Pond Reactor (RPR), respectively. Acute toxicity was monitored by assessing the sensibility of bioluminescent bacteria (Aliivibrio fischeri) to samples taken during reactions. In addition, by-products formed during solar photo-Fenton were identified by liquid chromatography coupled to mass spectrometry (UFLC-MS). For tests performed in lab-scale, two artificial irradiation sources were compared (UVλ > 254nm and UV-Visλ > 320nm). A complete design of experiments was performed in the semi-pilot scale RPR in order to optimize reaction conditions (Fe2+ and H2O2 concentrations, and water depth). Efficient degradation of carbendazim (> 96%) and toxicity removal were achieved via artificially irradiated photo-Fenton under both irradiation sources. Control experiments (UV photolysis and UV-Vis peroxidation) were also efficient but led to increased acute toxicity. In addition, H2O2/UVλ > 254nm required longer reaction time (60 minutes) when compared to the photo-Fenton process (less than 1 min). While Fenton’s reagent achieved high CBZ and acute toxicity removal, its efficiency demands higher concentration of reagents in comparison to irradiated processes. Solar photo-Fenton removed carbendazim within 15 min of reaction (96%, 0.75 kJ L−1), and monocarbomethoxyguanidine, benzimidazole isocyanate, and 2-aminobenzimidazole were identified as transformation products. Results suggest that both solar photo-Fenton and artificially irradiated systems are promising routes for carbendazim degradation.

Semiconductors based on Fe/Nb oxides can present both solar sensitivity and high catalytic activity. However, there is still a lack regarding the comparison between different routes to produce Fe/Nb-based solar photocatalysts and the evaluation of the impact of the synthesis operating conditions on the material properties. In this work, Fe/Nb2O5 ratio, type of precipitating agent, presence/absence of washing stage, and temperature of calcination were verified to be the most relevant parameters in the synthesis by the co-precipitation method. These factors led to remarkable differences in the properties and performance of the photocatalysts produced by each distinct synthesis route. Composition, iron species present in the materials, crystallinity characteristics, and pH of the catalysts were affected, leading to different photocatalytic activities under UV-Vis light. Due to their characteristics, the synthesized materials are potential photocatalysts for application in solar processes.

In this study, a multistage treatment system was proposed to treat real pharmaceutical wastewater containing the antibiotic amoxicillin. Ozonation (O3), and ozonation combined with aerobic biodegradation, were performed. The real pharmaceutical wastewater presented a high concentration of organic matter (TOC: 803 mg C·L-1 and COD: 2775 mg O2·L-1), significant amoxicillin content (50 mg L-1) and acute ecotoxicity (Aliivibrio fischeri aTU: 48.22). Ozonation proved to be effective for amoxicillin degradation (up to 99%) and the results also indicated the removal of the original colour of the wastewater, with average consumption of 1 g of ozone. However, the ozonation system alone could not achieve complete mineralization. Therefore, a combination of ozonation and biodegradation in a multistage system was proposed in order to improve cost and treatment efficiency. The multistage treatment system presented promising results, achieving degradation of more than 99% of the amoxicillin, more than 98% of the original chemical oxygen demand (COD), and 90% of initial toxicity, with the consumption of approximately 500 mg of ozone. This indicates that this system could prevent dangerous and biorecalcitrant antibiotics from entering water resources.

Multivariate techniques, like cluster analysis (CA) and principal component analysis (PCA), were used to evaluate the spatial and temporal variability of surface water quality in a large neotropical hydroelectric reservoir (Nova Ponte Reservoir). The dataset, obtained during the period of 1995–2011 from the Energy Company of Minas Gerais State (CEMIG), contains 14 parameters surveyed quarterly in 14 sites, at different depths. The CA grouped the 14 sites in three main groups: lotic sites, half of the photic zone sites and bottom sites. Statistical tests showed that only three parameters (total dissolved solids, nitrate and chemical oxygen demand) have no significant difference between cluster groups. The PCA results showed temporal changes of the water quality in all groups, illustrating modifications to the importance of the parameters over time. PCA also revealed the major causes of water deterioration from 1995 to 2005 were related to agricultural and livestock activities. Currently, the water quality parameters related to organic pollution are also highlighted. Generally, this study shows that possible optimization of the monitoring network should consider temporal variation of water quality parameters.

Resumo As indústrias têxteis utilizam grandes quantidades de água nos processos de tingimento e beneficiamento das fibras, gerando volumes elevados de efluentes contendo corantes, surfactantes, íons inorgânicos, agentes umectantes, entre outros. O principal impacto ambiental desses efluentes está relacionado com a absorção de luz no meio aquático, o que interfere na fotossíntese de plantas e algas. Sendo assim, é relevante um planejamento ambiental propiciando o aumento da remoção dos corantes, redução das perdas no tingimento e reúso da água. Neste trabalho, foram realizados estudos visando à proposição de medidas de contenção dos riscos ambientais e contribuir para melhor aderência aos conceitos da ecoeficiência no setor têxtil através de um estudo de caso. Os dados foram coletados em uma empresa localizada na área de abrangência do Rio Doce, Minas Gerais, sendo proposta a inclusão do Processo Oxidativo Avançado (POA) e ultrafiltração associada ao tratamento convencional para diminuição do volume gerado e características refratárias, e dessa forma oportunizando o reúso da água. Identificou-se a necessidade do monitoramento da toxicidade do lodo gerado em função da presença de teores de metais tóxicos visando seu reaproveitamento, sendo sugerido estudo para incorporação da massa em argila para fabricação de blocos cerâmicos de vedação utilizados na construção civil. Abstract Textile industries use large amounts of water in the processes of dyeing and processing of textile fibers, generating high volumes of wastewater containing dyes, surfactants, inorganic ions, wetting agents, among others. The main environmental impact of these effluents is related to the absorption of light into the water, which interferes with the photosynthesis of plants and algae. Therefore, it is relevant to have environmental planning aimed at the reuse of the water, increased removal of dyes, as well as reducing losses in the dyeing. In this work, studies were undertaken to propose control measures so as to introduce the concepts of Cleaner Production (CP) in the textile sector. Data was collected in a company located in the catchment area of the river Doce, in Minas Gerais, and established the association of the relative advantages of conventional coagulation/flocculation with the combined use of Advanced Oxidation Processes (AOP). The proposed measures entail a decrease in the volume and characteristics of the refractory sludge generated and the possibility of recirculation of treated effluent. The need to develop pilot-scale experiments was identified, including monitoring of the acute toxicity of treated effluents.

This review aims to gather main achievements and limitations associated to the application of solar photocatalytic processes with regard to the removal of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) from municipal wastewater treatment plant effluent (MWWTPE). Solar photocatalytic processes were chosen considering the context of developing tropical countries. Among these processes, solar photo-Fenton has been proved effective for the elimination of ARB from MWWTPE at neutral pH in bench and pilot scale and also under continuous flow. Yet, ARG removal varies as according to the gene. Irradiation intensity and matrix composition play a key role on treatment efficiency for this purpose. The use of sulfate radical in modified solar photo-Fenton is still incipient for ARB and ARG removal. Also, investigations related to ARB resistance profile and horizontal gene transfer rates after solar photo-Fenton treatment must be further analyzed. Regarding solar heterogeneous photocatalysis, TiO2 and TiO2-composites applied in suspension are the most commonly investigated for the removal of ARB and ARGs. Irradiation intensity, temperature and catalyst dosage affect treatment efficiency. However, most studies were performed in synthetic solutions using reduced sample volumes. Extended exposition times and addition of H2O2 to the system (solar/TiO2/H2O2) are required to prevent bacteria regrowth and ensure ARG abatement. In addition, enhancement of TiO2 with graphene or (semi)metals improved ARB elimination. Differences concerning irradiation intensity, matrix composition, catalyst dosage, and model ARB and ARGs used in studies analyzed in this review hinder the comparison of photocatalysts synthesized by various research groups. Finally, future research should aim at evaluating the efficiency of solar photocatalytic processes in real matrices originated from sewage treatment systems applied in developing countries; determining indicators of antimicrobial resistance in MWWTPE; and investigating ARB mutation rate as well as the removal of cell-free ARGs present in suspension in MWWTPE.

This work aimed to assess the elimination and inactivation of resistance-conferring plasmids (RCPs) present in suspension in secondary wastewater by solar photo-Fenton as these are important vectors for the dissemination of antimicrobial resistance. Experiments were performed in synthetic secondary wastewater (SWW) and municipal wastewater treatment plant effluent (MWWTPE). Solar photo-Fenton (50 mg L−1 of H2O2 and 30 mg L−1 of Fe2+) was carried out for 60 min at neutral pH by applying the intermittent iron addition strategy. The removal of RCPs was assessed by Real-Time Polymerase Chain Reaction (qPCR). The transformation of competent non-resistant E. coli was used to evaluate the inactivation of target RCPs harboring antibiotic resistance genes (ARGs) to ampicillin (pSB1A2) or kanamycin (pSB1K3) after treatment and controls. Solar photo-Fenton completely removed RCPs initially present in both matrixes (SWW and MWWTPE), showing enhanced performance compared to the dark Fenton process. Both RCPs were inactivated after 30 min of solar photo-Fenton treatment, while 60 min were necessary to achieve the same effect for the dark Fenton reaction under similar conditions. These results indicate the potential of solar photo-Fenton to improve wastewater quality and reduce the spread of antimicrobial resistance in the environment by hampering the discharge of cell-free RCPs present in suspension in MWWTP onto environmental waters., Graphical abstract Image 1, Highlights • Inactivation of plasmid via solar photo-Fenton assessed via E coli transformation. • Elimination of plasmid from wastewater via solar photo-Fenton assessed via qpCR. • Solar photo-Fenton removes plasmids carrying antibiotic resistance genes. • Solar photo-Fenton inactivates plasmids carrying antibiotic resistance genes. • Higher plasmid removal via solar photo-Fenton in simulated than real wastewater.

This is a post-peer-review, pre-copyedit version of an article published in Environmental Science and Pollution Research. The final authenticated version is available online at: http://dx.doi.org/10.1007/s11356-017-8425-7.

In this study, Na 2 S 2 O 8 , K 2 S 2 O 8 , H 2 O 2 , and CaO 2 were tested for the remediation of groundwater contaminated by a gasoline/ethanol blend. In fuel spills, groundwater acquires high organic carbon content and a considerable amount of BTEX (benzene, toluene, ethylbenzene, xylene), and can be treated using In Situ Chemical Oxidation. Batch tests were conducted to select the best oxidant, which establishes, in the presence of oxisol (soil rich in iron), the proper conditions for the generation of radicals. The results indicated that the H 2 O 2 added was scavenged in the process and that CaO 2 , which releases H 2 O 2 slowly, achieved the best removal results. However, this compound has low solubility, forms precipitates and increases pH to 12. Therefore, Na 2 S 2 O 8 was selected instead, once it achieved good removal results, worked at low pH values and had slow kinetics, making it suitable for groundwater remediation. Tests revealed that the concentration of iron in a ferriferous oxisol promotes proper oxidant activation, achieving 99% BTEX removal and 45% COD removal. GC–MS analysis of the oxidized samples showed the formation of intermediates (e.g. acetic acid and 1-acetic anhydride with formic acid) indicating the pathway of remediation. Despite such remarkable results, soil control sample achieved considerable DOC removal, suggesting that the use of ISCO may speed the remediation process, but the soil itself has a mechanism to degrade this kind of organic matter.

Este trabalho apresentou resultados obtidos nas capacitações dos colaboradores especializados em atendimento de grupos terapêuticos em unidades de pronto atendimento do Sistema Único de Saúde, Ipatinga, MG, Brasil. O objetivo desse trabalho foi explicitar para os treinados a relação entre a saúde ambiental e bem-estar social com ênfase no reaproveitamento de materiais não contaminados para minorar o volume ocupado em aterros sanitários. Constatou-se que a dinâmica da capacitação oportunizou ótica diferenciada quanto à importância do status ecológico. Além disso, o reconhecimento quanto à responsabilidade do indivíduo explicitada através da incorporação do reuso na prática individual, tal como, a produção de artefatos.

Solar photo-Fenton represents an innovative and low-cost option for the treatment of recalcitrant industrial wastewater, such as the textile wastewater. Textile wastewater usually shows high acute toxic and variability and may be composed of many different chemical compounds. This study aimed at optimizing and validating solar photo-Fenton treatment of textile wastewater in a semi-pilot compound parabolic collector (CPC) for toxicity removal and wastewater reclamation. In addition, treated wastewater reuse feasibility was investigated through pilot tests. Experimental design performed in this study indicated optimum condition for solar photo-Fenton reaction (20 mg L−1 of Fe2+ and 500 mg L−1 of H2O2; pH 2.8), which achieved 96 % removal of dissolved organic carbon (DOC) and 99 % absorbance removal. A toxicity peak was detected during treatment, suggesting that highly toxic transformation products were formed during reaction. Toxic intermediates were properly removed during solar photo-Fenton (SPF) treatment along with the generation of oxalic acid as an ultimate product of degradation and COS increase. Different samples of real textile wastewater were treated in order to validate optimized treatment condition with regard to wastewater variability. Results showed median organic carbon removal near 90 %. Finally, reuse of treated textile wastewater in both dyeing and washing stages of production was successful. These results confirm that solar photo-Fenton, as a single treatment, enables wastewater reclamation in the textile industry.

This work proposes the evaluation of an aluminized surface on the bottom of open reactors to perform a photo-Fenton process, at circumneutral pH (using Fe III-Ethylenediamine-N,N′-disuccinic acid complex), for elimination of micropollutants (MPs) in real effluents from municipal wastewater treatment plants (EMWWTP). Firstly, the strategy was to initially investigate the real EMWWTP spiked with several MPs (acetaminophen, diclofenac, carbamazepine, caffeine, trimethoprim and sulfamethoxazole) with 20 and 100 μg L−1 in a laboratory scale (evaluated by HPLC-UV) using a solar simulator. Finally, the removal of all MCs present in the real EMWWTP was monitored (evaluated by HPLC-MS) in a pilot-scale (90 L) in a raceway pond reactor (RPR). The treatment time required for degradation above 80% for the investigated MPs was over 30 min, and the predominant effect could be mainly associated with organics present in the real EMWWTP due to the light attenuation and scavenging of radical species. Moreover, the results confirmed that chloride and sulfate would most likely equally not affect the process. The use of an aluminized surface on the bottom of RPRs has been confirmed as a suitable option to improve the photo-Fenton reaction, enabling the use of lower doses of iron. Up to 60 different MPs found in EMWWTP have been successfully degraded using 0.1 mM of Fe at circumneutral pH with a consumption of 30 mg L−1 H2O2 with less than 45 min.

Raceway Pond Reactors (RPRs) have arisen as an interesting and feasible scaling-up option for treating substantial amount of wastewater by solar photo-Fenton process, a technology with short-term perspective due to its high contaminants of emerging concern (CEC) removal efficiency associated with a low reagents’ consumption (Fe and H2O2) and different strategies to work at near-neutral pH. This work proposes to modify the RPR optical pathway by using a reflexive surface of aluminum at the bottom of it. In this study, modified neutral solar photo-Fenton process with EDDS (Ethylenediamine-N,N'-disuccinic acid) has been applied for the elimination of a mixture of six micropollutants (acetaminophen, caffeine, carbamazepine, diclofenac, sulfamethoxazole, and trimethoprim) at 20 and 100 µg L−1 in natural water with different low iron concentrations (0.018-0-1 mM) and liquid depths (7–15 cm). Results showed a similar treatment time for 80% removal of micropollutants with 0.054 mM of iron using the aluminum surface and for 0.1 mM of iron without the surface. Utilizing a reflexive aluminum surface to return to reaction non-absorbed photons permitted to lower the consumption of iron and EDDS without losing efficiency.

In this study, photo-Fenton systems using visible light sources with iron and ferrioxalate were tested for the DOC degradation and decolorization of textile wastewater. Textile wastewaters originated after the dyeing stage of dark-colored tissue in the textile industry, and the optimization of treatment processes was studied to produce water suitable for reuse. Dissolved organic carbon, absorbance, turbidity, anionic concentrations, carboxylic acids, and preliminary cost analysis were performed for the proposed treatments. Conventional photo-Fenton process achieved near 99 % DOC degradation rates and complete absorbance removal, and no carboxylic acids were found as products of degradation. Ferrioxalate photo-Fenton system achieved 82 % of DOC degradation and showed complete absorbance removal, and oxalic acid has been detected through HPLC analysis in the treated sample. In contrast, photo-peroxidation with UV light was proved effective only for absorbance removal, with DOC degradation efficiency near 50 %. Treated wastewater was compared with reclaimed water and had a similar quality, indicating that these processes can be effectively applied for textile wastewater reuse. The results of the preliminary cost analysis indicated costs of 0.91 to 1.07 US$ m-3 for the conventional and ferrioxalate photo-Fenton systems, respectively. Graphical Abstract ᅟ.

O estudo se refere à experimentação científica. O público alvo constituiu-se em alunos do ensino médio. Argumentou em favor da educação socioambiental visando à proteção hídrica. Nessa premissa, foram aplicados testes em turmas de tratamento (1A e 1C), com experimentações científicas e uma turma controle (1B) que participou apenas das aulas teóricas. A análise dos resultados com Teste “t student” indicou que as diferenças apresentadas entre as turmas 1B/1A e 1B/1C foram significativas (p0,05), comprovando que as turmas com práticas laboratoriais alcançaram melhor entendimento. Reconheceu-se a relevância das práticas na compreensão da ciência.

In this work, blast furnace dust (BFD), a steel industry waste, was used as a demulsifier for highly efficient removal of the organic oil contaminant of metal working wastewater. Batch experiments showed that a simple mixture and stirring of BFD with stable emulsified wastewater containing metalworking oil (TOC ca. 15,000 mg L −1 and 1500 NTU) led to 90–98% TOC removal at pH lower than 7. Scanning electronic microscopy, X-ray diffraction, Mossbauer, thermogravimetric analysis, and Raman analyses suggest that the removal of the stable oil micelles is a combination of two synergic processes: (i) an electrostatic capture of the stable negatively charged oil droplets by the positive BFD particles followed by (ii) a strong interaction with the oil and the hydrophobic carbon surface. Preliminary results showed that BFD can be regenerated and reused by simple extraction or thermal treatment.

O presente trabalho buscou verificar a contribuição física, química e biológica do reservatório da Usina Hidrelétrica de Sá Carvalho, para o Rio Piracicaba, Bacia Hidrográfica do Rio Doce, Minas Gerais. Realizaram-se coletas quadrimestrais da água superficial (bruta), nos períodos de seca e chuva, entre novembro/2006 até julho/2012, em quatro pontos de coletados localizados em Nova Era (P1), Timóteo (P2), Coronel Fabriciano (P3) e Ipatinga (P4) nas proximidades do seu deságüe no Rio Doce. As variáveis limnológicas foram coletadas e avaliadas de acordo com CETESB (2006) e APHA (2005), enquanto os dados pertinentes ao reservatório foram obtidos através dos relatórios produzidos pela CEMIG (2012). Quanto ao reservatório constatou-se que em sua área da captação ocorrem atividades agropecuárias e extrativismo florestal com repercussões, tais como, a desertificação que promove alterações climáticas influenciando a concentração das substâncias químicas no corpo hídrico. Em todas as localidades desse estudo apurou-se IQA regular. Os piores resultados foram detectados na estação seca explicitando relação com a elevação da turbidez indicando melhor correlação em P4 sendo constatado que a redução da precipitação pluviométrica se constituiu em impeditivo para autodepuração sendo identificadas condições de intenso assoreamento também à jusante da UHE – Sá Carvalho. Constatou-se que a geração de energia elétrica não é principal responsável pela degradação do manancial perdendo para a siderurgia, mineração, esgoto sanitário e exploração florestal. Entende-se que deve ser intensificado o programa de preservação das áreas degradadas e educação ambiental visando o desenvolvimento sustentável da região de estudo.

In this work, the complexation of the hazardous β-lactamic antibiotic amoxicillin (AMX) with Fe3+ ions during coagulation was investigated. New bands in the ultraviolet-visible (UV-vis) spe...

The aim of this work is to evaluate the application of a steel waste, basic oxygen furnace sludge (BOFS), rich in iron, to treat water contaminated with elevated arsenic and sulfate concentrations. In the first step, three doses (10, 60, and 80 g L

In the present study, a multistage route is proposed for the treatment of biodiesel industry wastewater (BWW) containing around 1000 mg L

Ethylenethiourea (ETU) is a toxic degradation product of one class of fungicide which is largely employed in the world, the ethylenebisdithiocarbamates. In this study, ETU was degraded by ozonation enhanced by UV-C light irradiation (O

In this work, ozone oxidation of the antibiotics amoxicillin (AMX), cephalexin, and ceftriaxone was investigated in different samples: (i) aqueous solutions (100 mg L−1), (ii) an industrial wastewater containing AMX at 125 mg L−1 (chemical oxygen demand 6000 mg O2 L−1), and (iii) a heavily contaminated industrial wastewater containing the antibiotics at a total concentration of 320 mg L−1. High performance liquid chromatography, molecular absorption spectrophotometry in the ultraviolet/visible region, and total organic carbon measurements showed that ozonation of antibiotics solutions led to removal higher than 95% with 10–20% mineralization. Industrial wastewater also showed very good efficiency for antibiotic removal (80–98%) after ozonation. Moreover, Microtox® test showed 86% toxicity reduction for the industrial wastewater.

NaX zeolite-supported Nb2O5, ZnO, and FexOy photocatalysts were synthesized with the objective of producing photocatalysts that could be activated by visible/sunlight. The photocatalysts were prepared by wet impregnation with 10% (w/w) precursor. X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy were used to investigate the crystalline and electronic structures of the supported photocatalysts. The results obtained showed that Nb2O5 impregnation resulted in a synergistic effect with the zeolite matrix forming Nb2O5/NaX with a bandgap of 2.9 eV, which is lower than that of bulk Nb2O5 (3.2 eV). The synthesized β-FexOy (goethite) active-phase supported on NaX acted as a photocatalyst that could be activated by visible energy photons. A photocatalytically active phase was not observed for ZnO/NaX. Nb2O5- and β-FexOy-impregnated zeolite structures formed potential photocatalysts that absorb radiation with ultraviolet and visible wavelengths.

Bismuth complex oxides, in particular, bismuth tungstate, have recently attracted attention as promising photocatalytic materials for water treatment processes. In the present work, photocatalytic bismuth tungstate films were prepared by pulsed direct current (DC) reactive magnetron sputtering of Bi and W targets in an Ar/O2 atmosphere onto spherically-shaped glass beads. The uniform coverage of the substrate was enabled by the use of oscillating bowl placed underneath the magnetrons. The atomic ratio of Bi/W was varied through the variation of the power applied to the magnetrons. The deposited coatings were analyzed by the scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), X-ray photoelectron spectroscopy and atomic force microscopy. The photocatalytic properties of the films were studied via the methylene blue (MB) degradation process under artificial (fluorescent light) and natural (sunlight) irradiation, and compared to the photocatalytic performance of titanium dioxide coatings deposited onto identical substrates. The results showed that the photocatalytic performance of bismuth tungstate and bismuth oxide-coated beads was superior to that exhibited by TiO2-coated beads. Overall, reactive magnetron co-sputtering has been shown to be a promising technique for deposition of narrow band gap bismuth-based semiconducting oxides onto irregularly-shaped substrates for potential use in water treatment applications.

RESUMO: Nesse estudo, o principal objetivo foi mensurar a concentração de tório, urânio e potássio aplicando a técnica da análise por Ativação Neutrônica Instrumental em dois compartimentos ambientais, águas superficiais e sedimento marginal, do rio Piracicaba, em Minas Gerais. Esse rio possui área de drenagem que inclui as regiões do Quadrilátero Ferrífero da Região do Vale do Aço, sujeitando-se a intensa ação antropogênica. As amostragens ocorreram em quatro pontos de coleta, localizados nos municípios de Fonseca, Rio Piracicaba, Nova Era e Ipatinga, nas estações seca e chuvosa. As concentrações determinadas para aqueles elementos no sedimento se apresentaram elevadas em comparação com os valores usualmente observados para o perfil geológico na região de estudo, denotando relação com o modelo de exploração econômica, notadamente com a mineração e siderurgia. Evidencia, também, a relação com a degradação do feldspato potássico e do quartzo. Na água superficial, constatou-se o incremento da concentração do tório e potássio em comparação com os valores do Conselho Nacional do Meio Ambiente (CONAMA), nº. 357/2005. Os achados desse estudo explicitaram a necessidade da adoção de medidas mitigadoras, visando a contenção dos danos ambientais.

Recent research on novel cost-effective adsorbent materials suggests potential use of industrial wastes for effluent treatment, with the added benefit of reuse of the wastes. Waste steel materials, including blast oxygen furnace sludge (BOFS), blast furnace sludge (BFS), and blast furnace dust (BFD), were investigated as low-cost adsorbents for removal of an oil emulsion and RR195 dye. The residues were characterized by X-ray diffraction, Brunauer–Emmett–Teller area, volume and distribution of pore diameters, Mossbauer spectroscopy, X-ray fluorescence, granulometry, scanning electron microscopy/energy dispersive spectroscopy, and pHpzc. Adsorption kinetics data were obtained by UV–vis spectrophotometry at the maximum absorption wavelength of the dye solution and crude oil emulsion. The use of waste as an adsorbent was more efficient for treatment of the oil emulsion than the dye solution. BOFS had higher total organic carbon (TOC) removal efficiency than the other waste materials. For the RR195 dye, good color removal was observed for all adsorbents, >90 % within 24 h. TOC removal was poor

International audience; In this study, the degradation of four emerging contaminants (losartan potassium (LP), furosemide (FRSM), caffeine (CAF), and carbendazim (CBZ) under UV-C, UV-C/H2O2, and UV-C/S2O82- was investigated. A comparative evaluation of the efficiency of UV-C/H2O2 and UV-C/S2O82- in the degradation of these target CECs has not yet been reported. Moreover, target compounds were submitted to UV-C/AOPs individually in pure water and their simultaneous degradation was investigated in real surface water. Evolution of the acute toxicity of each compound during treatment was evaluated using Alivibrio fischeri. Quantum yields were determined for LP (0.011 to 0.016), FRSM (0.024 to 0.092), CAF (0.0007 to 0.0009), and CBZ (0.0016 to 0.0036) at different pH values. UV-C/H2O2 and UV-C/S2O82 achieved more than 98% removal of all compounds within 600 mJ cm-2, and pseudo-fist-order kinetic constants (k’app) for the degradation reactions were up to seven times higher in the presence of these oxidants when compared to k’app values obtained for UV-C photolysis. k’app measured for UV-C/H2O2 were higher than those calculated for UV-C/S2O82- except in the case of LP. Acute toxicity analysis suggested the formation of toxic intermediates during the UV-C photolysis of LP and FRSM, and the degradation of LP via UV-C/S2O82- also enhaced acute toxicity although electric energy efficiency per order identified UV-C/S2O82 as the most efficient process for the removal of this compound. Finally, different transformation products obtained during the degradation of caffeine under the different UV-C AOPs suggested that distinct degradation routes were involved in each treatment tested.

In this study, photocatalytic (photo-Fenton and H2O2/UV) and dark Fenton processes were used to remove ethylenethiourea (ETU) from water. The experiments were conducted in a photo-reactor with an 80 W mercury vapor lamp. The mineralization of ETU was determined by total organic carbon analysis, and ETU degradation was qualitatively monitored by the reduction of UV absorbance at 232 nm. A higher mineralization efficiency was obtained by using the photo-peroxidation process (UV/H2O2). Approximately 77% of ETU was mineralized within 120 min of the reaction using [H2O2]0 = 400 mg L(-1). The photo-Fenton process mineralized 70% of the ETU with [H2O2]0 = 800 mg L(-1) and [Fe(2+)] = 400 mg L(-1), and there is evidence that hydrogen peroxide was the limiting reagent in the reaction because it was rapidly consumed. Moreover, increasing the concentration of H2O2 from 800 mg L(-1) to 1200 mg L(-1) did not enhance the degradation of ETU. Kinetics studies revealed that the pseudo-second-order model best fit the experimental conditions. The k values for the UV/H2O2 and photo-Fenton processes were determined to be 6.2 × 10(-4) mg L(-1) min(-1) and 7.7 × 10(-4) mg L(-1) min(-1), respectively. The mineralization of ETU in the absence of hydrogen peroxide has led to the conclusion that ETU transformation products are susceptible to photolysis by UV light. These are promising results for further research. The processes that were investigated can be used to remove pesticide metabolites from drinking water sources and wastewater in developing countries.

This study investigated the use of blast furnace dust (BFD) as a catalyst to degrade an azo dye (RR195) by photo-Fenton-like processes. This waste contains hematite, magnetite and maghemite as iron sources, and its dissolution provides more Fe 3+ than Fe 2+ for the Fenton reaction in solution. The effect of hydrogen peroxide concentration and catalyst dosage on the kinetics of hydrogen peroxide decomposition and dye decolorization was also studied. The photo-Fenton-like process was compared to Fenton-like (using BDF without irradiation), Fenton and photo-Fenton (using FeSO 4 as iron source), UV/H 2 O 2 and UV processes. The results indicated that BFD can be effectively used as a catalyst in the photocatalytic process because it was able to completely degrade H 2 O 2 via an adjusted Langmuir–Hinshelwood model. Although the photo-Fenton-like reaction with BFD showed the same decolorization efficiency of RR195 as the homogeneous photo-Fenton process (using FeSO 4 ), the catalyst considerably increased the reaction rates (more than five times) according pseudo-first-order kinetics. The results of the irradiated systems using BFD can be more efficient in dye decolorization due to greater hydroxyl radical production through Fe 2+/ Fe 3+ cycling and by the occurrence of homogeneous and heterogeneous reactions. The practical use of the steel waste is promising, because it increases the reaction rates and its high density and magnetic proprieties enable an easy solid–liquid separation and reuse, making it a versatile material for environmental applications.

This study evaluated the adsorption capacity of ethylenthiourea (ETU) and 1H-1,2,4-triazole (1,2,4-T) for two commercial activated carbons: charcoal-powdered activated carbon (CPAC) and bovine bone-powdered activated carbon (BPAC). The tests were conducted at a bench scale, with ETU and 1,2,4-T diluted in water, for isotherm and adsorption kinetic studies. The removal of the compounds was accompanied by a total organic carbon (TOC) analysis and ultraviolet (UV) reduction analysis. The coals were characterized by their surface area using nitrogen adsorption/desorption, by a scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM/EDS) and by a zero charge point analysis (pHpcz). The results showed that adsorption kinetics followed a pseudo-second-order model for both coals, and the adsorption isotherms for CPAC and BPAC were adjusted to the Langmuir and Freundlich isotherms, respectively. The CPAC removed approximately 77% of the ETU and 76% of the 1,2,4-T. The BPAC was ineffective at removing the contaminants.

The Piracicaba River, Minas Gerais, presents corresponding extension to 241 km from its source in the Serra do Caraca to its mouth on the Doce River, totaling an area of 6,000 km 2 with several tributaries leading to the River Watershed Piracicaba (RWP). Among the localities of RWP highlights the metropolitan area of the Vale do Aco, which has high level of human pressure on water body according to their production profile (mining, steel, reforestation with eucalyptus, etc.) affecting ecosystem health. In this study prioritized examine the issue of surface water quality with emphasis on the process of eutrophication based on the measurement of the phosphorus and nitrogen concentration in different stations, and P 1 (Fonseca), P 2 (Rio Piracicaba), P 3 (Nova Era), P 4 (Coronel Fabriciano) and P 5 (Ipatinga) located around the Sa Carvalho hydroelectric power plant (HPP- Sa Carvalho). Surface water samples were collected on quarterly basis in the period from July / 2007 to July / 2012, paying attention separates the relevant seasonality of rainfall, compared with changes in physical and chemical parameters and analyzing the influence of hydropower in quality water. The data were worked by analyzing the relationship between nitrogen and phosphorus (N: P), Trophic Status Index (TSI) for total phosphorus and the Trophic State Index (TSI) for chlorophyll a showing an increase of nutrients being identified eutrophied conditions in several campaigns possibly related to the discharge of sewage, agricultural activities and industrial wastewater. This approach is finalized explaining the need for enforcement actions to contain the disturbances aimed at sustainable development and preservation of that water body.

– This study evaluates aerobic and anaerobic biodegradability and toxicity of a real pharmaceutical wastewater, which focuses on antibiotics production. Zahn-Wellens and Organization for Economic Cooperation and Development (OECD) methodologies were applied in order to verify the wastewater’s biodegradability and Microtox® analysis was performed for toxicity tests. Tests achieved more than 89% and 63% of Total Organic Carbon reduction, showing 80% and 50% of antibiotic removal, for aerobic and anaerobic processes, respectively. Moreover, acute ecotoxicological tests revealed that both techniques decreased the toxic character of real pharmaceutical wastewater. Desorption tests showed that the antibiotic was not degraded, but, in fact, adsorbed onto the sludge. Since biological treatment is the most widely used method for industrial wastewater treatment, this study indicates that this kind of treatment is probably unable to mineralize antibiotics present in pharmaceutical wastewaters, which may induce the development of resistant pathogens. Therefore, efforts must be taken to elucidate the main mechanisms of biological antibiotic removal from wastewaters since the presence of antibiotics in the environment is considered to be an emerging environmental issue.

É crescente a preocupação mundial com o desenvolvimento de tecnologias alternativas para o tratamento de águas residuárias direcionadas ao tratamento de efluentes complexos e reúso de águas. Neste sentido, o tratamento de efluentes por Processos Oxidativos Avançados (POA) configura-se como alternativa viável e eficiente na degradação de poluentes recalcitrantes. O POA Control – Grupo de Pesquisa e Aplicação de Processos Oxidativos Avançados no Controle da Poluição – foi criado no Departamento de Engenharia Sanitária e Ambiental(UFMG) para consolidar o desenvolvimento de tecnologias inovadoras para o tratamento de efluentes industriais de difícil degradação, com a publicação de várias teses, dissertações, artigos nacionais e internacionais e patentes. Este trabalho propõe revisar algumas das tecnologias desenvolvidas pelo grupo relacionando-as com o que vem sendo desenvolvido pela comunidade acadêmica internacional.

In this work, controlled reduction with H2 was used to transform blast furnace dust waste (BFD) into a versatile material for environmental applications, i.e., the reduction of the Reactive Red 195 (RR195) and Cr(VI) as well as the oxidation of RR195 by H2O2 in a heterogeneous Fenton reaction. Mossbauer, XRD and SEM analyses showed that treatment with H2 at different temperatures (400, 600 and 800 °C) reduced iron in the BFD to different phases, mainly Fe0/Fe3O4, Fe0/Fe3O4/FeO and Fe0. Reduction with H2 at 800 °C showed the highest activity for the reductive discoloration of the RR195 dye. Materials reduced at 400, 600 and 800 °C were active for the dye oxidation with H2O2, obtained complete discoloration with 32%, 21% and 5% of TOC removal, respectively. The material treated with H2 at 400 °C showed the best activity for the reduction of Cr(VI), with 81% removal after 180 min.