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Effects of environmental conditions on the emission and odor-active compounds from Fraxinus mandshurica Rupr Full text
2022
Wang, Qifan | Shen, Jun | Zeng, Bin | Wang, Huiyu | Wang, Weidong
Being one of the most common wood in furniture and decoration, Fraxinus mandshurica Rupr. (F. mandshurica) is a frequently used material for wood products. However, the resulting odor problem has not yet been solved so far. Thus, this study focused on exploring odor-active compounds and investigating the effect of environmental conditions on emission and odor attributes. F. mandshurica was studied via TD–GC–MS/O combined with microchamber. Totally, 15 kinds of key odor-active compounds were detected from F. mandshurica. The main odorous components were found to be aromatics, aldehydes and ketones, esters, alcohols and acids. Six kinds of attributes played a key role in the overall odor character of F. mandshurica. Fragrant was the predominant odor impressions, followed by vinegar and antiseptic solution. The proportion of the odor-active compounds concentration to total concentration decreased with an increase in the temperature and relative humidity, while the ratio of air exchange rate to the loading factor had little effect on this. The total concentration of F. mandshurica increased as the temperature and relative humidity increased, but these decreased as the ratio of air exchange rate to the loading factor increased, while the total odor intensity reduced with the rise in the ratio of air exchange rate to the loading factor. Time was found to be the most effective factor for eliminating emissions. Considering the environmental conditions in this study, 40 °C, 60% relative humidity and a 1.0 m³·m⁻² h⁻¹ ratio of air exchange rate to loading factor are recommended to accelerate the emission of F. mandshurica. The optimum condition was found to be higher temperature, higher relative humidity and higher ratio of air exchange rate to loading factor.
Show more [+] Less [-]Calcitic-based stones protection by a low-fluorine modified methacrylic coating Full text
2022
Pargoletti, Eleonora | Comite, Valeria | Fermo, Paola | Sabatini, Valentina | Annunziata, Luisa | Ortenzi, Marco Aldo | Farina, Hermes | Cappelletti, Giuseppe
Atmospheric pollutants, such as NOₓ, SO₂, and particulate matter, together with water percolation inside the stone pores, represent the main causes of cultural heritage decay. In order to avoid these undesired phenomena, the application of protective coatings represents a reliable solution. In this context, the present study focused on the synthesis of low-fluorine content methacrylic-based (MMA) polymeric resins characterized by seven F atoms (namely F7 monomer) in the lateral chains. Four different percentages (1.0, 2.5, 5.0, and 10.0%) of the present monomer were adopted to obtain a final polymeric structure showing the desired hydrophobicity, processability, and structural and thermal stability (even after accelerated UV aging tests). MMA_F7(1.0) seemed to be the optimal one; therefore, it was further applied onto Candoglia marble. Specifically, the treated substrates showed good surface hydrophobicity, water repellency, and water vapor transpirability. No color variation was observed even after a 1.5-year exposure in a real polluted environment (Monza Cathedral). Interestingly, the application of this coating hindered the atmospheric nitrates penetration inside the stones and, at the same time, it limited the sulfates (gypsum) formation, thus revealing a very promising marbles protection resin.
Show more [+] Less [-]Size-tunable effect of CaCO3/nanocellulose hybrid composites on the removal of paracetamol from aqueous solution Full text
2022
Shaheen, Tharwat I. | El-Shahat, Mahmoud | Abdelhameed, Reda M.
Paracetamol is a ubiquitous drug used by animals and humans but is not fully metabolized within their bodies, and thus often finds its way into raw wastewater. This study represents a new class of adsorbent nanocomposite with high adsorption capacity towards paracetamol removal. Herein, both the kinetic study and the removal of paracetamol from aqueous solutions were investigated in terms of diverse CaCO₃/nanocellulose composites with different surface charges and different particle sizes. To fine-tune these parameters, the latter was hydrothermally synthesized by manipulating of three nanocelluloses types. Precisely, micro-crystalline cellulose (MCC), nano-crystalline cellulose (CNC), and nano-fibrillated cellulose (NFC) were used as templates for precipitating CaCO₃ particles from CaCl₂ solution with the aid of Na₂CO₃. Results revealed the successful in situ deposition of calcite form of CaCO₃ with size varied relying on the base of nanocellulose. For MCC, CNC, and NFC, the size of CaCO₃ was disclosed in the range of 850–1200 nm, 350–600 nm, and 150–200 nm, respectively, regarding their surface charge. While the process of paracetamol adsorption was described by Freundlich and Langmuir isotherms, it was observed that, for MCC, the best fit of the experimental data was achieved with the Freundlich model, while the Langmuir model was the most appropriate for CNC and NFC. Also, the highest max adsorption capacities of paracetamol varied respectively to both size and surface charge of hybrid composite used. Among them, MCC/CaCO₃ composite exhibited the highest max adsorption capacity at 428 mg g⁻¹, clarifying that the low surface zeta potential of the latter hybrid nanocomposite is responsible for the accumulation of CaCO₃ at a bigger size with a higher affinity to adsorb paracetamol with the highest capacity due to its weak repulsion. Results also demonstrated that the material is highly effective and economical for removal of paracetamol and reusability with marginal diminishing in adsorption capacity up to 10% after five reuse cycles.
Show more [+] Less [-]Assessment of Lead Origin in Forest Soils of the Czech Republic Using Isotopic Ratios Full text
2022
Johanis, Hana | Tejnecký, Václav | Drábek, Ondřej | Borůvka, Luboš | Mihaljevič, Martin
Forest soils play an important role in the global ecosystem, providing many beneficial services. Protection of forests and their soils from anthropogenic impacts is therefore of utter importance to conservation efforts. Lead (Pb) is one of the most widespread anthropogenic pollutants and has been introduced into forests of the Czech Republic since medieval times, mostly from smelting, coal burning, and later also leaded gasoline. Lead can cause serious damage to the environment and forest soils and whose levels in the environment thus need to be closely monitored. In order to best evaluate possible sources of Pb pollution, 120 soils were sampled across forest areas of the Czech Republic. These sites were selected to be in areas largely unaffected by major pollution sources such as highways, large cities, and industrial complexes. Soils were digested using aqua regia and analyzed using ICP-MS for Pb isotopic ratios. Sampled forest soils have displayed isotopic signatures in a range of 1.1635–1.2269 for ²⁰⁶Pb/²⁰⁷Pb and 2.3918–2.5235 for ²⁰⁸Pb/²⁰⁷Pb and have had mostly uniform isotopic signature, with mean values of 1.1779 ²⁰⁶Pb/²⁰⁷Pb and 2.4624 ²⁰⁸Pb/²⁰⁷Pb, likely stemming from widespread atmospheric pollution. The exception to this uniformity was floodplain forests (average ²⁰⁶Pb/²⁰⁷Pb 1.1939, ²⁰⁸Pb/²⁰⁷Pb 2.4610), potentially due to a greater influx of materials from the river bed or surface runoff. These findings may aid future conservation efforts in determining background values for soil Pb and monitoring the state and health of forests in the Czech Republic.
Show more [+] Less [-]The nexuses between carbon emissions, agriculture production efficiency, research and development, and government effectiveness: evidence from major agriculture-producing countries Full text
2022
Yasmeen, Rizwana | Tao, Rui | Shah, Wasi Ul Hassan | Padda, Ihtsham Ul Haq | Tang, Caihong
Agriculture production efficiency and carbon emissions have become the challenge for the sustainable world. Therefore, this study explores the relationships between agriculture production and carbon emissions in major (seventeen) agriculture-producing countries over the time period of 1996–2018. Data envelopment analysis is applied to estimate the efficiency of agriculture sector production. The results suggested that the USA, Russia, Korea, Japan, and Italy were efficient agriculture production. Among BRICS countries, China (0.183), India (0.378), and Brazil (0.382) are far off to Russia in Agriculture production efficiency. Growth of research and development investment by 1% increases agriculture production efficiency by 0.0773 (full panel), 0.119 (developing), and 0.0245(developed), respectively. Carbon emissions are also significantly decreased by research and development investment. However, the effectiveness of the government on carbon emissions can be both positive and negative in developed and developing countries’ cases. Nevertheless, both developed and developing governments are concerned about increasing agriculture production efficiency. The shape validity of the environmental Kuznets curve is also varied between the developed and developing groups. From the policy perspective, it is suggested that the government should reform its policies to avoid carbon activities and enhance the agricultural sector on a priority basis to increase the efficiency of current raw resources, generate jobs, and reap a variety of other advantages.
Show more [+] Less [-]Effects of the soaking-related parameters in a combined freezing-based seawater desalination process Full text
2022
Yang, Hui | Jiang, Yuanfei | Wang, Rui | Dong, Bingyan | Fu, Mengxiao
A combined freezing, soaking, and centrifugal desalination (FSCD) process was employed to desalt seawater taken from Bohai Bay. The seawater was frozen into two kinds of sea water ice having different texture and size using either commercial refrigerator or experimental setup. For both kinds of ice samples, the influences of soaking-related parameters on the desalination effect were studied. For most ice samples treated with FSCD process, the salt removal efficiencies are higher than 90%. The purity of ice product increases as increasing soaking time and at higher initial soaking liquid temperature, while the ice yield rate decreases. At the same ice yield rate, the salt removal efficiency for ice flakes is higher than that for crushed ice samples, whereas when the raw seawater of 27 °C is used as soaking liquid, FSCD process is not feasible due to too lower ice yield rate.
Show more [+] Less [-]Wastewater treatment plant effluent and microfiber pollution: focus on industry-specific wastewater Full text
2022
Ramasamy, Rathinamoorthy | Aragaw, Tadele Assefa | Balasaraswathi Subramanian, Raja
The production, use, and disposal of synthetic textiles potentially release a significant amount of microfibers into the environment. Studies performed on municipal wastewater treatment plants (WWTPs) effluent reported a higher presence of microfibers due to the mix of domestic laundry effluent through sewage. As municipal WWTPs receive influents from households and industries, it serves as a sink for the microfibers. However, research on textile industry WWTPs that primarily treat the textile fabric processing wastewater was not explored with the concern of microfibers. Hence, the review aims to analyze the existing literature and enlighten the impact of WWTPs on microplastic emission into the environment by specifically addressing textile industry WWTPs. The results of the review confirmed that even after 95–99% removal, municipal WWTPs can emit around 160 million microplastics per day into the environment. Microfiber was the dominant shape identified by the review. The average microfiber contamination in the WWTP sludge was estimated as 200 microfibers per gram of sludge. As far as the industry-specific effluents are analyzed, textile wet processing industries effluents contained > 1000 times higher microfibers than municipal WWTP. Despite few existing studies on textile industry effluent, the review demonstrates that, so far, no studies were performed on the sludge obtained from WWTPs that handle textile industry effluents alone. Review results pointed out that more attention should be needed to the textile wastewater research which is addressing the textile wet processing industry WWTPs. Moreover, the sludge released from these WWTPs should be considered as an important source of microfiber as they contain more quantity of microfibers than the effluent, and also, their routes to the environment are huge and easy.
Show more [+] Less [-]The influence of palm oil fuel ash heat treatment on the strength activity, porosity, and water absorption of cement mortar Full text
2022
Shaladi, Ramzi J. | Johari, Megat Azmi Megat | Zainal Arifin Ahmad, | Mijarsh, Mustafa Juma A.
The current study aims to explore the impact of palm oil fuel ash (POFA) heat treatment on the strength activity, porosity, and water absorption of cement mortar. The cement mortar mixtures were typically comprising cement or cement in combination with ultrafine treated POFA (u-TPOFA) which is the final form of the treated POFA, sand, water, and a superplasticizer. Before utilizing the u-TPOFA in mortar mixtures, the treatment processes of POFA were undertaken via five steps (drying at 105 ℃, sieving, grinding, heat treatment, re-grinding) to form u-TPOFA. The heat treatment was performed at three different heating temperatures (i.e., 550 ℃, 600 ℃, and 650 ℃). The ratio on mass/mass basis of the blended ordinary Portland cement (OPC) with u-TPOFA was OPC:u-TPOFA of 70%:30%. A total of four mixtures were prepared, consisting of a plain control mixture (designated as PCM) and three mixtures containing 30% of u-TPOFA treated at three different temperatures designated as M1 “550 ℃,” M2 “600 ℃,” and M3 “650 ℃”. The results show that the optimum mixture was M2 which achieved the highest strength activity index (SAI) of 101.84% and 107% among all mixtures at 7 days and 28 days, respectively. Meanwhile, the porosity (P%) and water absorption (Abs%) of M2 exhibited the lowest values of 9.3% and 4.5%, respectively, among all the mixtures at 28 days. This superior performance of u-TPOFA treated at 600 ℃ represented in the M2 mixture was due to the formation of more binding phases consisting of calcium silicate hydrate (C–S–H) type gel originated from a higher pozzolanic reaction and the filler effects caused by the fine u-TPOFA microparticles. These observations were further confirmed by the improved performance of the M2 mix among all the designed mixes which also exhibited better results in terms of bulk density (BD), ultrasonic pulse velocity (UPV), X-ray diffraction (XRD) as well as thermogravimetry (TGA) and field emission scanning electron microscopy (FESEM-EDX) analyses.
Show more [+] Less [-]gCN-P: a coupled g-C3N4/persulfate system for photocatalytic degradation of organic pollutants under simulated sunlight Full text
2022
Shen, Mengdi | Zhang, Xiaodong | Zhao, Shan | Wang, Shuguang
A coupled g-C₃N₄/PDS system, named gCN-P, has been put forward to degrade refractory organic pollutants under simulated sunlight which integrates photocatalysis and PS-AOPs (advanced oxidation of persulfate based on sulfate radicals). The coupled g-C₃N₄ and PDS showed superior synergistic effect for MO degradation under simulated sunlight. Results showed that almost all MO was removed in the gCN-P system after irradiation for 80 min under simulated sunlight. The degradation rate of gCN-P system was improved by 12.6 and 4.9 times compared to single PDS and g-C₃N₄ systems, respectively. And only by adding 0.01 g of persulfate into the gCN-P system. The results of quenching experiments and EPR showed that O₂⁻, ¹O₂ and h⁺ were main active species for the degradation of MO in the gCN-P system under simulated sunlight. Application of the gCN-P system in tap water samples demonstrated its excellent performance in real-world water environment, and the gCN-P system was employed for removing other new contaminants such as bisphenol A, ciprofloxacin, and paracetamol. The results demonstrated the gCN-P system can effectively remove organic pollutants under sunlight in practices.
Show more [+] Less [-]Traffic noise and adiposity: a systematic review and meta-analysis of epidemiological studies Full text
2022
Gui, Si-Yu | Wu, Ke-Jia | Sun, Yue | Chen, Yue-Nan | Liang, Huan-Ru | Liu, Wen | Lu, Yao | Hu, Cheng-Yang
Traffic noise has attracted much attention as a significant and intractable public health threat. This study was designed as a systematical review to explore the association of traffic noise with different indicators of obesity, thus providing updated quantitative estimates for the pooled effect estimates of the existing literature. We conducted an extensive search for epidemiological studies that investigated the association of traffic noise with obesity in three electronic databases till February 23, 2021. We used random-effects meta-analysis to calculate the summary effect estimates for each 10-dB(A) increase in noise and compared the highest with the lowest category of noise in relation to seven obesity indicators. Meanwhile, we assessed the risk of bias and the overall quality of the evidence of each study as well as the level of evidence for each exposure–outcome pair. The initial search identified 30 studies, 13 of which were ultimately included. The meta-analysis for the highest versus the lowest category of noise exposure was generally associated with higher waist circumfluence (WC) ranging from 0.326 cm (95% confidence interval (CI) = 0.078, 0.574) to 0.705 cm (95% CI = 0.071, 1.340) and higher odds of central obesity ranging from 1.055 (95% CI = 1.000, 1.109) to 1.167 (95% CI = 1.037, 1.298). When the continuous exposure (each 10 dB(A) increase in noise) was introduced, similar results were found. This study indicated positive associations of traffic noise with WC and central obesity. However, in consideration of some limitations, there is an urgent need for future studies to increase the sample size, discriminate the etiological differences in different noise and obesity indicators, and thoroughly consider socioeconomic status.
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