Effects of different nitrogen/phosphorus ratios on the growth and metabolism of the microalgae Scenedesmus obliquus cultivated in the wastewater mixture from primary clarifiers and sludge thickeners (2023)

Process Safety and Environmental Protection, Volume 170, 2023, pp. 817-823

This article presents a comprehensive mathematical model used to describe ozone (O₃) Mass transfer in hollow fiber membrane contactor (HFMC) system. With the model, the effects of operating parameters and membrane specifications, such as gas and liquid phase flow rates, porosity to tortuosity and membrane length, on dissolved ozone at the reactor outlet and ozone concentration distribution. Furthermore, experimental data were used to validate the generated simulation model and it was observed that there is a reasonable agreement between the experimental results and the model outputs in terms of dissolved ozone at the reactor outlet at different water and ozone flow rates. initial concentrations. . According to the simulation results, the gas flow and the porosity (ε) in the tortuosity ($t$) had no effect on the dissolved ozone at the reactor outlet, while there was a slight increase in the ozone concentration at the outlet with increasing membrane length. Furthermore, the main resistance for ozone mass transfer was the liquid phase, and the gas phase and membrane subdomain resistance for ozone mass transfer was indicated as lower due to the higher ozone diffusion coefficient in the gas phase.

Process Safety and Environmental Protection, Volume 170, 2023, pp. 834-841

Air curtains are often used as separation barriers to reduce the transfer of dust, heat and smoke between two areas. When people travel from one place to another, they bring with them dust and air currents known as contrails. To limit the spread of toxins within the home, it is important to understand the man-made footprint. This study examines the usefulness of air curtains in preventing human-induced wake movement. We also use an air curtain to monitor air flow, dust flow and particulate transfer from a contaminated area to a cleaner area in the chamber. A dust sensor and particulate matter sensor were used to assess real-time monitoring of dust and particulate matter._2.5,10generated particles as well as the man-made trail. The experiment was carried out in a different position (horizontal, vertical, wedge) of the air curtain unit (ACU) and different wing angles (10°-15°, 15°-30°, 30°-45°) with and without the human walk. Maximum efficiency for the horizontal was 47% at 30°-45°, for the wedge position it was 74% at 15°-30° and for the vertical it was 81.4% at angles of 30°-45° . Maximum efficiency was found to be 81.4% with a vertical direction of 30°-45°. This can help achieve maximum PM reduction in public and commercial offices.

Process Safety and Environmental Protection, Volume 170, 2023, pp. 808-816

Composting is an efficient way to recycle waste. Strong mineralization leads to loss of organic carbon components in the biodegradation process, which affects the quality of composite products. Calcination technology was introduced to improve the ability of clay minerals to adsorb and retain organic carbon components and was applied to chicken manure composting. Five treatments were performed (control group (CK), calcined montmorillonite (M-), montmorillonite (M), calcined illite (I-) and illite (I)). The results showed that calcined clay minerals reduced organic carbon losses (CK: 57.22%, M-: 54.56%, M: 56.86%, I-: 52.39% and I: 56.08% ) and significantly reduced most of them to humic form. acids. Therefore, the properties of the carbon components were more stable and ultimately improved the quality of the final composite products. Meanwhile, the network complexity, interactions and contribution of core bacteria involved in organic carbon formation were improved in calcined clay mineral treatments by microbial analysis. Furthermore, a series of statistical computer analyzes confirmed that the specific structure of calcined clay minerals can sequester organic carbon, enhancing the role of core bacteria and physicochemical factors. Therefore, this article revealed the mechanism of calcined clay minerals sequestering organic carbon and proposed rational recommendations for the practice of composting.

Heliyon, 2022, artigo e12540

Cleaner Production Magazine, Banda 364, 2022, Article 132658

The production of biodiesel from microalgae faces obstacles at all stages, starting with the cultivation of microalgae strains for biomass production, followed by harvesting, drying, oil extraction and transesterification, leading to higher production costs. In this study, an approach was adopted to minimize the cost of biomass production using locally available agricultural fertilizers, i. h Urea, NPK 10 26 26, diammonium phosphate, potassium, superphosphate, etc. for the cultivation of green microalgaetetradesmusoblíquowhich can be used for the production of biodiesel and bio-oil. To this end, an optimized urea (OUr) medium was developed that reduced production costs by 47 times compared to commonly used N 11 medium formulated with analytical grade inorganic salts. This optimized medium further increased the biomass yield by 32% and reduced the requirement for key nutrients such as potassium, magnesium sulfate and superphosphate by 29, 25 and 25%, respectively. However, the urea requirement was increased by 20%. Culture of the Sewer Lagoonabout Ta biomass productivity of 12.6 g was shown in the newly formulated medium⁻²Label⁻¹followed by 10.9 g during winter⁻²Label⁻¹in summer and 4.8 g⁻²Label⁻¹in the rainy season at a cultivation depth of 30 cm, resulting in an estimated biomass productivity of 30.04 tons per hectare⁻¹Again⁻¹, and a biodiesel productivity of 2.07 tons hectares⁻¹Again⁻¹. The fuel properties of the biodiesel produced showed properties comparable to those of petrodiesel and also were within the limits specified by national and international standards. Organic crude oil productivity of 10 ton hectares⁻¹Again⁻¹was extrapolated from the defatted biomass. Therefore, this study managed to use >40% of the biomass for the simultaneous production of biodiesel and biological crude oil from the same biomass and finally paved the way for the development of a microalgae refinery, studying the biomass consumed for other applications.

Technology Powder, Band 415, 2023, Artikel 118196

To mitigate contamination by low-frequency microwave radiation, a group of BPC-CoFe₂o₄/[Email protected]The composites were obtained by regulating the biologically based porous carbon in two different ways, solvothermal loading with magnetic particles and post-annealing. Research shows that technical parameters have a great influence on the microwave absorption mechanism of manufactured absorbers, in which APC-700 has excellent impedance matching property over a wide low frequency range and is integrated with current loss multilevel polarization magnetic alloy parasite, ferrite self-resonance, electron hopping and conduction loss, as well as structural dissipation with special porous morphology, can achieve a wide low-frequency EAB of 2.15GHz in just 1, 5 mm, with a maximum RL of -39.48 dB at 1.22 GHz for 2 mm. This indicates the potential application of the compound produced here to resolve the aforementioned low frequency radiation contamination.