工业工程最新文献

Mercury pollution from a chlor-alkali plant has caused a long-term impact on the northwest of the Persian Gulf. In this article, the history of mercury concentration in Musa estuary, Iran, is summarized from previous research and reports and used to estimate the health risk assessment. Despite the closure of the chlor-alkali plant in 2016, the mercury level in sediments and biota is still higher than the acceptable standards in some parts of the estuary. Mercury concentrations and bioaccumulation in the food chain, including fish, crustaceans, birds, and humans, were evaluated. Health risk assessments indicate that consuming some fish species may put children and adults at risk of mercury exposure. Further study is required to fill the gaps for mercury monitoring and recovery.

In this study, an Artificial Neural Network-Genetic Algorithm (ANN-GA) approach was successfully applied to optimise the physicochemical factors influencing the synthesis of unsaturated fatty acids (UFAs) in the microalgae P. kessleri UCM 001. The optimized model recommended specific cultivation conditions, including glucose at 29 g/L, NaNO₃ at 2.4 g/L, K₂HPO₄ at 0.4 g/L, red LED light, an intensity of 1000 lx, and an 8:16-h light-dark cycle. Through ANN-GA optimisation, a remarkable 66.79% increase in UFAs production in P. kessleri UCM 001 was achieved, compared to previous studies. This underscores the potential of this technology for enhancing valuable lipid production. Sequential variations in the application of physicochemical factors during microalgae culture under mixotrophic conditions, as optimized by ANN-GA, induced alterations in UFAs production and composition in P. kessleri UCM 001. This suggests the feasibility of tailoring the lipid profile of microalgae to obtain specific lipids for diverse industrial applications. The microalgae were isolated from a high-mountain lake in Colombia, highlighting their adaptation to extreme conditions. This underscores their potential for sustainable lipid and biomaterial production. This study demonstrates the effectiveness of using ANN-GA technology to optimise UFAs production in microalgae, offering a promising avenue for obtaining valuable lipids. The microalgae's unique origin in a high-mountain environment in Colombia emphasises the importance of exploring and harnessing microbial resources in distinctive geographical regions for biotechnological applications.

The photochemistry of organic contaminants present in ice is receiving growing attention, given the wide presence of ice during winter in temperate regions as well as Polar and mountain environments. Differences between ice photochemistry and aqueous photochemistry, however, influence the quantitative fate and transformation of organic chemicals present in freshwater, marine and ice-cap environments and these differences need to be explored. Here we comparatively studied the ice and aqueous photochemistry of three antibiotics [levofloxacin (LVX), sulfamerazine (SM), and chlortetracycline (CTC)] under the same simulated sunlight (λ > 290 nm). Their photodegradation in ice/water followed pseudo-first-order kinetics, whereby the photolytic rates of LVX in ice and water were found to be similar, SM photodegraded faster in ice, while CTC underwent slower photodegradation in ice. Whether individual antibiotics underwent faster photodegradation in ice or not depends on the specific concentration effect and cage effect coexisting in the ice compartment. In most cases, the fastest photodegradation occurred in freshwater ice or in fresh water, and the slowest photolysis occurred in pure-water ice or in pure water. This can be attributed to the effects of key photochemical reactive constituents of Cl⁻, HA, NO₃⁻ and Fe(III), that exist in natural waters. These constituents at certain levels showed significant effects (P < 0.1) on the photolysis, not only in ice but also in water. However, these individual constituents at a given concentration, serve to either enhance or suppress the photoreaction, depending on the specific antibiotic and the matrix type (e.g., ice or aqueous solution). Furthermore, extrapolation of the laboratory findings to cold environments indicate that pharmaceuticals present in ice will have a different photofate compared to water. These results are of particular relevance for those regions that experience seasonal ice cover in fresh water and coastal marine systems.

Microplastics (MPs) (<5 mm) are a growing environmental problem and have garnered significant global interest from scientists and policy makers. Coastal ecosystems are vulnerable to MP pollution, and assessing their sources, fate, and transport in the environment is imperative for marine ecosystem health. Data for marine sediment are still limited, particularly in the Pearl River Estuary (PRE) ecosystem in China. Here, we assessed the abundance, characteristics, and risks of MPs in marine sediment from PRE. MPs abundance ranged from 2.05 × 10³ items ·kg⁻¹ to 7.75 × 10³ items ·kg⁻¹ (dry weight), and white and black MPs were the dominant colors. The majority (>64.12 %) of detected MPs were <0.85 mm and primarily consisted of pellets (36.84 %) and fragments (29.65 %). Three polymer types of MPs were identified by Fourier Transform Infrared Spectroscopy (FT-IR) including polyethylene (PE), polyethylene terephthalate (PET), and polypropylene (PP). Polyurethane (PU) sponge was reported for the first time in this study area. Observations of the surface morphology of typical MPs using Scanning Electron Microscopy (SEM) showed that all MPs exhibited varying degrees of erosion, characterized by cracks, folds, and bumpy structures. Based on type and quantity of MPs and the polymers identified, we assessed and classified the risk of MP contamination in PRE sediment as category III, indicating severe ecosystem contamination. Our results may serve as an effective model for other estuaries facing similar pollution regimes and provides valuable information for marine sediment risk assessment.

Urban terrorism is a significant global concern, prompting extensive scholarly inquiry into its underlying causes and effects. However, a comprehensive literature review summarizing this body of knowledge is notably absent. Thus, this study seeks to address this gap by conducting a thorough examination of existing literature on terrorism, particularly focusing on urban contexts, to identify key patterns and recurring themes. The study identified 515 research articles using the keywords "urban" and "terrorism" through the Web of Science and Scopus databases. A bibliometric review was conducted, which included a historical background, author keywords, country and institution, citation, and co-citation analyses. The findings revealed an increase in the number of studies on urban terrorism following the 9/11 attacks in the United States, which accounted for the highest number of publications in the country. Most studies were conducted in government law, international relations, and urban studies. Keyword analysis revealed that counterterrorism, security, and disasters were more closely linked to terrorism. Thematic analysis identified six main themes related to urban spaces and terrorism: tourism, governance, resilience, public health, economy, security, and counterterrorism. This study emphasizes the importance of involving the public in counterterrorism efforts in addition to traditional approaches to addressing urban terrorism.

Organochlorine pesticides are chlorinated hydrocarbon compounds. The production and use of organochlorine pesticides have been restricted around the world because they are persistent and toxic and able to undergo long-range transport and bioaccumulate. It is necessary to develop efficient techniques for eliminating organochlorine pesticides from environmental media, and we also need to better understand how these techniques operate. Understanding how organochlorine herbicides behave in various environmental settings is very crucial. We looked on the photodegradation of endosulfan (endosulfan I and II) and hexachlorobenzene (HCB), two common organochlorine insecticides. Tests were conducted with pesticides at different concentrations, dissolved in various organic solvents, and exposed to light at different wavelengths. Density Functional Theory (DFT) was employed to study solvent effects. Degradation kinetics followed first-order models. The pesticides dissolved in various organic solvents showed a decrease in their degradation rates in the following order: toluene > acetone > n-hexane. It was discovered that there was a good chance the Cl atoms on the benzene ring in HCB would be eliminated through nucleophilic processes. It was discovered that endosulfan breaks preferentially at the SO double bond. The findings will aid in the development of strategies for successfully eliminating organochlorine pesticides from environmental media by aiding in the prediction and assessment of the photochemical behaviors of the pesticides under various environmental circumstances.