Electrochemical treatment of effluent for the removal of contaminants of emergent concern and culturable microorganisms

project CEMOWAS2 (SOE2/P5/F0505) UIDB/04085/2020 CEECIND/04210/2017The present work aims to study the electrochemical (EC) process applied for the removal of contaminants of emergent concern (CECs) from wastewater after secondary treatment and the effect of the process on the total culturable microorganisms. The EC experiments were performed in a cylindrical open reactor with 500 mL of effluent, and a fixed current density of 8 mA/cm² was applied through mixed metal oxide electrodes. The experiments were conducted in different sets. In the first round (Set 1), the effluent sample was spiked with three CECs (200 ppb each): Caffeine (CAF), carbamazepine (CBZ), and oxybenzone (OXY). For the best treatment period, 6 h, electrodegradation rates ranged from 41 ± 7% for CAF to 95 ± 6% for OXY, with an 87% removal of total culturable microorganisms. In the second round (Set 2), aiming to assess EC process efficiency in a more complex CEC mixture, the effluent was spiked with six more CECs (200 ppb each): Diclofenac (DCF), triclosan (TCS), bisphenol A (BPA), 17β-estradiol (E2), 17α-ethinylestradiol (EE2), and ibuprofen (IBU), giving a total of nine CECs. In this case, the EC process allowed decreasing the CEC content by 19-100% (below the limit of detection), depending on the effluent samples, and the culturable microorganisms by 99.98% after a 6 h treatment. By contributing to CEC degradation and microorganism removal, the EC process proved to be a viable remediation and disinfection technology for secondary effluent from wastewater treatment plants.publishersversionpublishe

Electrodialytic recovery of rare earth elements from coal ashes

Fundação para a Ciência e a Tecnologia, I.P., Portugal, UIDB/04085/2020 (Research unit CENSE “Center for Environmental and Sustainability Research”). Fundação para a Ciência e a Tecnologia is also acknowledged for N. Couto Contract established under Individual Call to Scientific Employment Stimulus (CEECIND/04210/2017).Rare earth elements (REE) are critical raw materials crucial for modern technologies and used in a variety of industries. There is a need of investment in REE recovery from secondary sources. The present work was designed to assess the potential of the electrodialytic process to recover REE from coal ash. The content of REE was evaluated in bituminous and anthracite ash. Anthracite presented higher REE concentration (447 ppm vs. 138 ppm) and a triple concentration of critical REE compared with bituminous ash. Anthracite ash was treated aiming to test the REE recover potential, including differences between light REE (LREE) and heavy REE (HREE) fractions as well as the specific recovery of REE with high criticality. A two-compartment electrodialytic cell was tested with the matrix placed in the anode compartment and a cation-exchange membrane separating the compartments. Experiments lasted a maximum of 7 days applying different current intensities and pH adjustment in the catholyte (≈ 2). Three main steps are observed in the removal process 1) REE solubilization - from the solid to the liquid phase (anolyte); 2) REE mobilization - movement from the anolyte towards the cathode end; 3) REE removal - presence in the catholyte. The extent of each step observed for the REE depends on their individual position in the periodic table with HREE removal being more regulated by step 1 and LREE by step 2. At the best tested conditions (50 mA, 3 days, pH adjustment), more than 70% of REE were extracted from the ash with the catholyte enclosing up to ≈ 50% of LREE and HREE. Combining the high criticality of neodymium with its high concentration in anthracite coal ash (65 ppm), the electrodialytic treatment is highly recommended to concentrate this REE in the catholyte. The results demonstrated the proof-of-concept for electro-assisted extraction of REE from anthracite coal ash, opening perspectives to a selective recovery of these elements from secondary sources.authorsversionpublishe

Mulheres na agricultura familiar: uma análise no estado do Pará

O artigo caracteriza o perfil da mulher na agricultura familiar paraense, com base em dados do Censo Agropecuário de 2017. As análises apresentam as características gerais, produtivas e tecnológicas dos estabelecimentos agropecuários familiares gerenciados por agricultoras, assim como aspectos relacionados ao associativismo, acesso à assistência técnica e crédito rural. No estado do Pará, 57.473 estabelecimentos agropecuários são gerenciados por mulheres, o que representa 20% do total. A maior parcela delas (53%) possui mais de 45 anos de idade. O nível de escolaridade é baixo e se dedicam, principalmente, ao cultivo de lavouras temporárias, quintais agroflorestais e a criação de pequenos animais, visando a segurança alimentar do grupo familiar e a comercialização de excedentes. Os resultados indicam a necessidade de maior equidade de gênero, pois a “invisibilidade” da mulher e o baixo acesso às políticas públicas, ainda é traço marcante no meio rural. Destacam-se os baixos percentuais de acesso dessas mulheres aos serviços de assistência técnica e extensão rural e aos financiamentos via crédito rural, instrumentos fundamentais para a inovação e sustentabilidade dos sistemas de produção. Conclui-se que as lacunas de gênero continuam a se configurar como um dos principais óbices ao desenvolvimento rural sustentável

Pharmaceutically Active Compounds in Wastewater Treatment Plants: Electrochemical Advanced Oxidation as Onsite Treatment

Emerging organic contaminants are one of the main threats to the environment and society. The primary source of these contaminants in the environment is wastewater treatment plants (WWTPs) that cannot eliminate all of these compounds. Pharmaceutically active compounds (PhACs) deserve special attention as new substances are constantly being developed, and the number of these compounds that reach consumers is increasing. The consequences of PhACs to human health are not yet subjected to regulatory criteria or norms; nevertheless, chronic toxicity in biodiversity has already been reported. In response to global environmental concerns, there has been increasing interest in sustainable solutions to remove these compounds from effluent in WWTPs. Electrochemical technologies developed for effluent treatment were designed to promote PhAC degradation and safe effluent discharge. Understanding the relationship between different anode characteristics and electrochemical oxidation performance is essential for developing a cost‐efficient technology to remove contaminants from wastewater. In this context, the performance of graphite and platinized electrodes were compared in the electrochemical oxidation of selected emerging organic contaminants in a recirculating flow reactor.proofepub_ahead_of_prin

Towards a Sustainable Future: Advancing an Integrated Approach for the Recycling and Valorization of Agricultural Plastics

Plastic pollution has become a pressing environmental issue. The agricultural sector, in particular, is a significant contributor to this problem, given the widespread use of plastics in farming practices and a lack of and/or use of inefficient approaches for the recycling and valorization of agricultural plastic waste. This has resulted in the accumulation of these residues in landfills and/or their improper disposal, which has exacerbated their environmental impact, leading to negative consequences on soil, water, and ecosystems. This work provides an overview on the current methodologies available to address the challenges associated with inadequate management of agricultural plastics and highlights the need for a comprehensive and systematic methodology, involving material development, polymer processing, waste collection, sorting, and valorization. It emphasizes the importance of collaboration between polymer producers, polymer manufacturers, farmers, policymakers, waste management companies, and recyclers to develop effective, technical, and economically viable recycling and valorization schemes. This paper addresses gaps and provides guidance on possible solutions, specifically polymer development, policy instruments, regulatory frameworks, collection schemes, and the technical approaches required for the adequate valorization of agricultural plastic waste. Furthermore, it highlights the associated barriers and benefits of the different presented approaches. It also aims to promote awareness on agricultural plastic waste and provide guidance on the best approaches to reduce its environmental impact

Hydrocarbon‐Contaminated Soil in Cold Climate Conditions: Electrokinetic‐Bioremediation Technology as a Remediation Strategy

Oil is one of the more toxic pollutants in the environment. Due to the fragility of the Arctic environment to anthropogenic disturbances, the persistence and severity of ecological impacts from oil spills can be significant. The development of non‐invasive and sustainable solutions for soil remediation is a pressing problem. The feasibility of electrokinetic technology as a remediation strategy to enhance oil removal from soil under cold climate conditions was assessed. The soil was collected in Sisimiut, Greenland from a dump site after an oil spill. A range of temperatures and different strategies for applying electric current were tested in experiments over 14 days. The soil showed a total petroleum hydrocarbon concentration of 69 500 mg kg−1, and the levels decreased between 43% and 78%. The effect of the electric field for oil removal was not verified when compared with controls. Naturally cold‐adapted microorganisms seemed to have a strong influence on oil remediation under the tested conditions.proofepub_ahead_of_prin