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•Photocatalytic inactivation of real bioaerosols was performed in continuous flow.•Bioaerosol emissions of 1 × 108 Cells m−3air were treated from a steady-state biofilter.•Flow ...cytometer analysis indicated that bioaerosols was composed by 80% bacteria.•ZnO/Perlite achieved 30% higher inactivation of bioaerosol than TiO2/Perlite.•Photo-oxidative activity of ZnO was directly associated with cell death.
Biological processes for waste treatment are the main source of bioaerosol emissions in urban environments; these air pollutants have detrimental effects on human health, and therefore the development of treatment processes for this kind of pollutants is of high priority. The present work focused on the implementation of photocatalytic systems based on Perlite-supported ZnO and TiO2 to inactivate fungal/bacterial emissions from a biofilter treating ethyl acetate vapors in a steady state process. The results showed that the outlet of the biofilter had a bioaerosol concentration between 1.0 × 106 Cells m−3air and 460.0 × 106 Cells m−3air. Flow cytometer characterization coupled with a viability kit indicated that bioaerosol emission was composed mainly of bacteria (>80%). The photocatalytic system based on ZnO/Perlite achieved the highest percentage of bioaerosol inactivation (70%), with a catalyst activity duration of 7.5 h, while the TiO2/Perlite system showed an inactivation percentage of 40% with a maximum time of photocatalytic activity of 2.0 h. The main mechanism of bioaerosol inactivation was associated with cell death and not with cell damage.
•A novel phase change material wallboard has been fabricated.•A self-made vacuum absorption roller was used to prepare phase change material wallboard.•A heat accumulator was developed to connect ...with solar heating system.•Heat accumulator with paraffin extended operation time of active solar system.•Phase change material passive and active combination decreased energy consumption.
Phase change material (PCM) used in buildings can increase building energy efficiency and decrease indoor temperature fluctuation. In this study, composite PCM was composed of paraffin and expanded perlite (EP) (60wt%, 40wt%) and was prepared through a self-made vacuum absorption roller. A phase change material wallboard (PCMW) was fabricated by the prepared composite PCM through the mould forming method. A plate-type heat accumulator (HAR) with embedded copper tubes was connected to a solar thermal heating system. HAR is fully filled with paraffin, which can store or release the heat gained by the solar thermal heating system. Therefore, PCM active and passive combination is realised through the PCMW incorporated in the building wall and the HAR connected to the solar thermal heating system in the same building. In order to analyze the performance of PCM active and passive combination, two same cubes were used to conduct a contrastive experimental study using different strategies under the winter conditions. The experimental result has indicated that (1) PCMW with melting point of 24.88°C and latent heat of 59.68J/g was incorporated in the walls, passively enhancing the thermal inertia of building envelope; (2) HAR with PCM extended the service period of solar thermal heating system; (3) PCM active and passive combination further enhanced the thermal performance of building envelope, indoor thermal comfort and building energy efficiency.
A hydroponics system developed using a nutrient film technique was used to evaluate the effectiveness of rice husk biochar (RB) alone or in combination with perlite (PL) as substrates for increasing ...the growth of leafy vegetables compared with that of PL. Seedlings of cabbage, dill, mallow, red lettuce, and tatsoi were grown hydroponically in PL, RB, and PL + RB (1:1 ratio of PL to RB, v/v) substrates for a 30-d under optimal environmental conditions in a greenhouse. Shoot length and fresh/dry masses of cabbage, dill, and red lettuce plants grown in RB substrate were decreased by 49% on average compared to those plants grown in PL substrate. In contrast, PL + RB substrate led to approximately 2-fold increases in shoot length, number of leaves, and fresh/dry masses of leafy vegetable plants compared with those grown in PL substrate. Foliar nutritional composition (Ca, Mg, K, Na, Mn, Fe, and Zn) and nitrogen status (SPAD index) of plants grown in PL + RB and PL substrates suggested the presence of optimal growth conditions for ensuring optimum yield with high quality. In addition, RB substrate contributed to respective increases of 1.2–3.5-fold in leaf K, Mg, Mn, and Zn contents in most vegetable plants compared with those grown in PL substrate. The RB alone or in combination with PL substrates decreased algal growth in the nutrient solutions as confirmed by scanning electron micrographs of microalgae on the RB surface. The results also indicated that use of PL + RB hydroponic substrate could be an alternative and effective technology for the better management of unwanted algal growth in nutrient solutions and high production of leafy vegetables.
•Perlite + biochar increased yield of leafy vegetables higher than that in perlite.•Biochar removed algae from the nutrient solutions, ensuring healthy vegetables.•This is the first report on removing algae from the nutrient solutions by biochar.
•Novel composite phase change materials with two phase change peaks for thermal energy storage were prepared.•The obtained composite phase change materials exhibited good leakage-proof ...performance.•The obtained composite phase change materials have good thermal stability and reliability.•The thermal performance of the composite phase change materials for building were investigated.
Thermal energy storage with phase change materials (PCM) is of great significance for increasing energy efficiency and energy saving. In this paper, a novel capric acid-myristyl alcohol/expanded perlite composite PCM (CPCM) with two phase change peaks were prepared. The capric acid-myristyl alcohol (CM) were synthesized by capric acid (CA) and myristyl alcohol (MA) (WCA and WMA = 9:1). Three kinds of expanded perlites (EP) were employed as support materials in the prepared CPCM. The chemical structure, morphology, thermal properties, leakage and thermal energy storage performance of the CM/EPPCM were investigated. The results indicate that the CM/EPPCM has a good thermal stability and leakage-proof performance. In addition, the thermal characteristics of the CM/EPPCM were investigated using a building model. The experimental results shows that the application of the CM/EPPCM for building envelope can effectively reduce temperature fluctuation and improve the thermal comfort of the building.
•Highest herbal yields in soilless purslane grown on a combination of tuff-peatmoss.•Highest protein and lipid contents in purslane grown on tuff-peatmoss-perlite.•Highest total phenolics and ...flavonoids in purslane grown on tuff-peatmoss-perlite.•Highest antioxidant activity in tuff-peatmoss-perlite and zeolitic tuff.•Soilless purslane is a good source of proteins, lipids, and antioxidant phenolics.
Purslane (Portulaca oleracea L.) is a valuable plant and crop with potential industrial uses, yet little is known on how its cultivation could benefit from soilless substrates. This study aimed to assess the effects of different soilless growth media on herbal yields (fresh and dry), proximate chemical composition, total phenolic, flavonoid and anthocyanin content, and antioxidant activity of purslane cultivated in a closed system. The greatest yields over five harvest cycles were obtained with tuff-peatmoss (2:1 mixture) compared with other soilless substrates, although the edible leaves were not as rich in proteins, lipids, minerals, and phenolic compounds. The highest content of proteins (31.4% and 30.4%), lipids (0.68% and 0.75%), total phenolics (646.9 and 684.9 mg/100 g), flavonoids (597.8 and 563.8 mg/100 g), and moisture (92.5% and 93.5%) in the leaves were found in purslane grown in tuff-peatmoss-perlite (2:1:1) and in zeolitic tuff, respectively. Antioxidant activity of leaf extracts was also the highest in purslane grown in both substrates and was similar to the antioxidant activity of leaf extracts from soil-grown purslane obtained commercially and from the wild. The protein and lipid content obtained with tuff-peatmoss-perlite (2:1:1) and zeolitic tuff were superior to those of soil-grown purslane. The results show that the nutritive and antioxidant qualities of purslane can be enhanced through soilless cultivation and selection of suitable culture media.
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•Surfaces of expanded perlites were modified by a rotating-bed PECVD method.•The rotating-bed reactor was used for agitation of particles during the depositions.•Surface of expanded ...perlite was successfully transformed into super-hydrophobic.•The water content percentage of expanded perlite was reduced from 70% to below 5%.•PECVD avoids many problems associated with existing liquid-based coating techniques.
In this study, an RF plasma discharge was employed to deposit thin poly(hexafluorobutyl acrylate) (PHFBA) polymeric films on expanded perlite. A rotating plasma reactor was used to provide effective agitation and mixing of the particles during the depositions. Surface of expanded perlite, a hydrophilic porous material, was successfully transformed into super-hydrophobic due to the highly fluorinated chain of PHFBA. Deposition rates up to 42nm/min were observed. The influences of plasma discharge conditions on wettability and water holding capacity of expanded perlite powders were investigated. Chemical and morphological properties of uncoated and coated expanded perlites were determined by SEM (EDS), FTIR, and contact angle measurements analyses. It is observed that the pulsed plasma approach helps to minimize undesirable monomer fragmentation while providing better film structure. It also should be emphasized that PECVD experiments did not change the morphology of the expanded perlite powders. The water holding capacity of expanded perlite was decreased from 70% down to around 4% upon coating on pulsing mode.
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•One efficient photocatalysis nanocomposites were synthesized by a one-pot simple solvothermal synthesis method.•As a floating photocatalytic material, this nanocomposite is ...synthesized by depositing one metal semiconductor (BiOI) on the surface of expanded perlite (EP), with high performance of light, low-cost, high photocatalytic efficiency and low biocytoxicity.•This nanocomposite could be reused for the degradation of diesel at least five times.
Nowadays, oil spills have occurred frequently, which is seriously harmful to the aquatic wildlife and the ecological environment. The photocatalysis is one important approach to degrade the diesel. The diesel floats on the water surface and is difficult to be removed by direct photocatalysis. However, floating photocatalytic composites can solve this problem. We used one facile solvothermal synthesis method to deposit the metal semiconductor (BiOI) on the expanded perlite (EP) and obtained one efficient photocatalysis nanocomposites, which could float on the water surface with good efficient adsorption and excellent degradation of the diesel. And the experimental results shows a good photocatalytic performance, which is up to 85% of removal rate of the diesel after irradiation for 2 h under simulated sunlight. In addition, this composite is a recycled material (reusing for 5 times) and eco-friendly material with low biotoxicity. As a result, the proposed combination of adsorption and photocatalysis will provide a novel strategy to greatly facilitate the treatment of diesel wastewater.
•A novel expanded perlite based composite phase change material (PCM) is developed.•A sodium acetate trihydrate-formamide mixture is used as the PCM.•The supercooling degree of the mixture is reduced ...by adding a nucleating agent.•The composite PCM has a melting point of 40.5 °C and an enthalpy of 148.3 J/g.•A good thermal performance is achieved by the composite PCM when applied in roof.
Introducing a phase change material (PCM) with large latent heat, low thermal conductivity, and appropriate phase change temperatures into building roof favors reducing indoor temperature fluctuation and increasing thermal comfort, thus helping to realize building energy conservation. Herein, a sodium acetate trihydrate (SAT)-formamide (FA) mixture was combined with expanded perlite (EP) to prepare a novel composite PCM. It is shown that adding tetrasodium pyrophosphate decahydrate at a loading of 3 wt% can reduce the supercooling degree of the mixture from 34.5 °C to 0.4 °C. The obtained mixture, composed of 77.6 wt% of sodium acetate trihydrate, 19.4 wt% of formamide and 3 wt% of tetrasodium pyrophosphate decahydrate, can be absorbed into EP to prepare a form-stable composite PCM at a mass fraction of 55 wt%, which has a melting point of 40.5 °C and an enthalpy of as large as 148.3 J/g. This composite PCM possesses good thermal reliability and has a thermal conductivity of as low as 0.0978 W/(m·K). The thermal performance of the composite PCM when employed in the roof of a test room was investigated and compared with those of the previously reported CaCl2·6H2O/EP composite PCM and EP. It is found that, the test room with the SAT-FA/EP composite in the roof exhibits slower temperature rise and drop rates, a reduction in the highest temperature, and an increase in thermal comfort, compared with those containing the CaCl2·6H2O/EP composite PCM and EP. The better thermal performance of the SAT-FA/EP composite is attributed to its larger latent heat and more suitable phase change temperatures for use in roof, thereby showing great potential for practical applications.
Different stages in the production of expanded perlite provide various types of waste by-products that could be used in the building industry, thus supporting a sustainable environment. In this ...study, the use of waste perlite powder (WPP) at a high content as a filler material in self-compacting concrete (SCC) was investigated. The combination of blast furnace slag cement as the main binder, along with metakaolin (MK) as a supplementary cementitious material (SCM), helped us produce several normally vibrated concrete (NVC) and SCC mixtures with low clinker content (190–220 kg/m3). To ensure the appropriate rheological properties for SCC production, filler materials were added to the SCC mixtures, and the rheological properties of the fresh concrete and the mechanical and durability properties of the hardened concrete were investigated. The results indicated that WPP had a significant pozzolanic effect on the concrete microstructure, resulting in a positive impact on the compressive strength of the concrete. Furthermore, enhanced durability properties of SCC mixtures incorporating WPP was obtained.
•Waste perlite powder (WPP) can be applied as a filler in the production of self-compacting concrete (SCC).•WPP has a positive pozzolanic effect on the strength gain of SCC at a low clinker content.•Metakaolin can be used along with WPP for enhanced mechanical and durability properties.
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•Green synthesis of Pd/perlite nanocomposite using Euphorbia neriifolia L. leaf extract.•Reduction of nitroarenes and organic dyes in water.•Characterization of catalyst by XRD, ...FESEM, EDS, and TEM.•The catalyst can be recovered and reused for further catalytic reactions with almost no loss in activity.
A facile and one-step green process to synthesize palladium nanoparticles (Pd NPs) dispersed on perlite is reported. In this study, for the first time, we describe the successful assembly of the Pd/perlite nanocomposite using Euphorbia neriifolia L. leaf extract as a reducing and stabilizing agent. The Pd/perlite nanocomposite showed high efficiency in the catalytic reduction of nitroarenes such as 4-nitrophenol (4-NP), 2,4-dinitrophenilhydrazine (2,4-DNPH) to the corresponding amines. This catalyst also could exhibited a high activity toward the reduction of organic dyes such as Congo red (CR), Rhodamine B (RhB) and methyl orange (MO) by NaBH4 in aqueous solution with high level of reusability. The catalytic reduction reactions were monitored by employing UV–Vis spectroscopy. The structure, morphology, and physicochemical properties were characterized by various analytical techniques such as transmission electron microscopy (TEM) images, field emission scanning electron microscope (FESEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction analysis (XRD) and FT-IR spectroscopy.
