Search Results (7)

Urban micro-tidal canals frequently suffer from severe hypoxia due to restricted hydrodynamic exchange and untreated discharges. Field monitoring during a 2022 mass fish mortality event at the Dongsam tidal canal revealed that during the ‘tidal window gap’—a hydraulic stagnation period required for passive tidal flushing—bottom-layer dissolved oxygen (DO) plummeted to a lethal 0.44 mg/L. To address the limitations of passive tidal exchange, this study proposes a conceptual hybrid water purification framework integrating active ecological interventions: wall-mounted spiral flow aeration for continuous oxygenation and vertical bio-curtains for pollutant interception. By synergizing fluid mechanics with ecological engineering, core design parameters were systematically derived: an effective mixing width ($W_{eff}=2.2 h$), longitudinal spacing ($L_s$ = 13.6$\times W_{eff}$), an optimal root immersion ratio ($D_r/h$ = 0.6), and climate-adaptive planting densities (${\rho }_p\approx$12–32 plants/m²). Additionally, a corrosion-resistant FRP guide rail system was incorporated to facilitate autonomous adaptation to tidal fluctuations. The framework was conceptualized through a prototype design for the Dongsam canal and subsequently scaled to 15 international micro-tidal canals across diverse climatic zones. The optimized bilateral staggered configuration established a continuous 528 m² ecological refuge, ensuring DO levels recover above the critical 3 mg/L threshold. Ultimately, this research presents a comprehensive methodological framework and a flexible engineering toolkit to guide water quality and ecological resilience enhancements in shallow urban waterways worldwide. Full article

Driven by environmental sustainability concerns, the integration of bio-based components in curtain wall systems is gaining traction in both research and the construction market. This paper explores the development and validation of a bio-based façade system within the Basajaun H2020 project (2019–2024). The project aimed to demonstrate the feasibility of introducing environmentally friendly bio-based components into the mature curtain wall façade industry. The paper focuses on identifying technological solutions for replacing key components such as frame profiles, insulation, and the tightness system with bio-based and less environmentally impactful alternatives, presenting the results achieved in the façade system design of the Basajaun project. These solutions aimed at creating a bio-composite-based curtain wall façade that adheres to the current building envelope standards and normative, implementing diverse façade typologies for vision panels, opaque sections, and integrated windows and, moreover, engineering the prefabrication process for industrialization and enabling wider market replication and simplified transport and installation. The results demonstrate that the Basajaun façade successfully integrates selected components and meets the performance requirements set by regulations: the façade is designed to withstand a maximum and typical wind load of 3.5 kN/m² and a typical load of 1.5 kN/m², the weighted sound reduction index obtained is R_w = 44 dB, and the thermal transmittance of the vision façade is 0.74 W/m²K while that of the entire opaque façade is 0.27 W/m²K (an additional internal wall is required to achieve the requested thermal transmittance)—the values are in accordance with reference standards and design requirements. However, questions remain regarding the workability of bio-based profiles as a commercially viable, ready-to-market solution that can replace traditional aluminum profiles in the curtain wall façade industry. Full article

This research explores the development and validation activities of a bio-based façade system within the Basajaun H2020 project, focusing on enhancing the utilization of bio-based components within building envelopes to replace conventional solutions with eco-friendly alternatives. This paper reports the methodologies employed to detect requirements and outline the testing protocols undertaken to validate the façade system design devised within the project, focusing on the original façade components as the biocomposite profile. Vision and opaque façade modules are prototyped and tested following curtain wall standards for performance (EN 13830:2015) and acoustic assessments (EN ISO 717-1:2020) to showcase the efficacy of the developed solution. The conducted tests demonstrate the feasibility of integrating bio-based components as alternatives to conventional materials into building envelopes, aligning with project expectations and prevailing standards for curtain wall façade solutions. Notably, the designed façade system meets technical conditions and research objectives. Nevertheless, the paper underscores the need for further refinements to facilitate solution industrialization and explore broader market applicability focusing on the biocomposite profile. Full article

As the construction industry moves toward sustainable building practices, incorporating wood-based materials into building envelope systems has become a priority. This paper investigates the environmental impact of three custom bio-composite Façade System Modules (FSMs) through an Embodied Carbon Assessment (ECA), focused on the Global Warming Potential indicator of life cycle stages from cradle to practical completion (A1–A5). The evaluated FSMs were developed within the Basajaun H2020 project (G.A. 862942), by substituting and combining conventional materials with other bio-composite products to form hybrids from bio-based polymers and wood. A benchmark ECA was conducted, simulating alternative FSMs devised with common practice solutions for the curtain wall façade to facilitate a comprehensive comparison. The life cycle inventory encompassed detailed technical information, fostering the utilization of primary data for accuracy. The study particularly highlights considerations over three technological systems of the modules that incorporate increased use of wood-based components and a novel bio-composite material: the frame profiles, the insulation equipment, and the seal system. Despite the challenges due to the Basajaun FSMs’ weight, the findings reveal that replacing the currently used materials with wood-based materials and bio-composites reduced the embodied emissions, particularly substituting aluminum frame profiles. The insights presented here offer indicators toward circular, environmentally conscious, bio-composed building envelopes, emphasizing the need for continued analysis and refinements as a consequence of increasing the accuracy of the available primary data from the supply chain and concerning end-of-life scenarios. Full article

Pyrolysis is a combustion process of woody biomass conducted under low or no oxygen conditions. It converts any kind of biomass into biochar, bio-oil, or biogas. Hence plants’ woody material can also be converted into bioenergy products. Valorization of woody biomass in the form of energy-rich compound biochar is a more sustainable technique as compared to conventional burning which leads to toxicity to the environment. Innovations and the need to limit open burning have resulted in numerous mobile and fixed plant pyrolysis methods that burn a variety of woody residues. Production technologies that reduce the need for open burning, the main source of potential pollutants, fall under the regulations in the Clean Air Act of 1990. This Act is the legal instrument to regulate air pollution at its source across the United States of America and it is implemented and enforced through the Environmental Protection Agency, in coordination with sister agencies. One newer innovation for reducing wood residues and emissions is an air curtain incinerator. Currently, the Clean Air Act regulates stationary solid waste incinerators, and this is also applied to mobile air curtain incinerators burning woody biomass. However, other woody biochar production methods (e.g., flame cap kilns) are not subjected to these regulations. Discrepancies in the interpretation of definitions related to incineration and pyrolysis and the myriad of differences related to stationary and mobile air curtain incinerators, type of waste wood from construction activities, forest residues, and other types of clean wood make the permit regulations confusing as permits can vary by jurisdiction. This review summarizes the current policies, regulations, and directives related to in-woods biochar production and the required permits. Full article

Bio-curtain (i.e., curtain) is a permeable cover equipped with a spraying system for ammonia (NH₃) control in a swine facility. Previous studies investigated the NH₃ reduction effects primarily based on concentration units. It is challenging to determine the actual efficiency because of the large amount of air discharged through the large surface of the curtain, and external wind rapidly dilutes and disperses the exhausted air. Therefore, this study investigates a technique to evaluate the NH₃ reduction effect of the curtain in terms of emission rate. We constructed a metallic cover with a single hole around the curtain to gather the air discharged through it. The NH₃ reduction effect was calculated by comparing the NH₃ emission rate that was monitored in the barn exhaust fan and at the single hole of metallic cover during the non-spray and spray treatments inside the curtain at the maximum and minimum operating rate of the barn’s exhaust fan. NH₃ emission rates declined both non-spray and spray at the minimum operation rate of the barn exhaust fan, but the reduction effect was higher in spray conditions than non-spray. Accumulating NH₃-absorbed water inside the curtain under the low ventilation of the exhaust fan caused these circumstances. Full article

To understand how SARS-CoV-2 spreads indoors, in this study bovine coronavirus was aerosolized as simulant into a plexiglass chamber with coupons of metal, wood and plastic surfaces. After aerosolization, chamber and coupon surfaces were swiped to quantify the virus concentrations using quantitative polymerase chain reaction (qPCR). Bio-layer interferometry showed stronger virus association on plastic and metal surfaces, however, higher dissociation from wood in 80% relative humidity. Virus aerosols were collected with the 100 L/min wetted wall cyclone and the 50 L/min MD8 air sampler and quantitated by qPCR. To monitor the effect of the ventilation on the virus movement, PRD1 bacteriophages as virus simulants were disseminated in a ¾ scale air-conditioned hospital test room with twelve PM2.5 samplers at 15 L/min. Higher virus concentrations were detected above the patient’s head and near the foot of the bed with the air inlet on the ceiling above, exhaust bottom left on the wall. Based on room layout, air measurements and bioaerosol collections computational flow models were created to visualize the movement of the virus in the room airflow. The addition of air curtain at the door minimized virus concentration while having the inlet and exhaust on the ceiling decreased overall aerosol concentration. Controlled laboratory experiments were conducted in a plexiglass chamber to gain more insight into the fundamental behavior of aerosolized SARS-CoV-2 and understand its fate and transport in the ambient environment of the hospital room. Full article