•Softwood BC (pH 10.9) was substituted for peat in a 70-30 peat-perlite mixture.•Substrates were or were not adjusted to pH 5.8 and were used to grow marigolds for 9 wk.•Substrates without pH ...adjustment converged from pH 4.4–10.4 to pH 5.6–7.5 by wk 9.•BC substitution for peat did not negatively impact marigold biomass or flowering.•BC can replace peat (≤70% vol) in soil-free substrates and without pH adjustment.
Peat moss has historically been a key component of soil-free substrates in the greenhouse and nursery industries. However, the increasing expense of peat, negative impacts of peat mining on wetland ecosystems, and growing perception of peat as unsustainable have led to investigation for alternatives. Biochar (BC) is a promising substitute for peat, yet the majority of studies examine additions of BC to peat-based substrates rather than replacing the peat component or employ relatively low substitution rates. Furthermore, at high substitution rates the alkalinity common to many BCs may increase substrate pH and adversely impact plant production. We evaluated BC substitution for peat and pH adjustment of resulting substrates on marigold (Tagetes erecta L.) performance under standard greenhouse conditions. A high pH (10.9) softwood BC (800°C) was substituted for peat in a standard 70:30 (v/v) peat:perlite mixture at 10% total volume increments. Substrate pH was either not adjusted or adjusted to pH 5.8 using a BC by-product, pyroligneous acid (PLA). Germination was inhibited in pH adjusted substrates with high BC substitution (50–70% total substrate volume) likely due to higher dosages of PLA needed to neutralize pH. At harvest (flowering stage, 9 weeks) the initial pH gradient (4.4–10.4) in substrates that were not pH adjusted had converged to pH 5.6–7.5, and BC substitution for peat did not negatively impact marigold biomass or flowering. At low substitution rates (10–30% total substrate volume), marigold biomass and leaf SPAD values were greater than the control peat-perlite mixture (0% BC). This study demonstrates that softwood BC can be considered as a full replacement for peat in soil-free substrates, and even at high rates (70% total substrate volume) does not require pH adjustment for marigold production. Crop- and BC-specific considerations and economic potential should be investigated for wider application.
In this research work, we deposited rGO QDs on the surface of flower-shaped hierarchical Bi-Bi2WO6/EP (Expanded Perlite) floating photocatalyst via the facile-liquid-phase deposition route. The rGO ...QDs-Bi-Bi2WO6/EP is the EP-based floating nanocomposite which is consisting of 3C heterojunction (rGO QDs, Bi2WO6 and Bi nanoparticles). In as-fabricated rGO QDs-Bi-Bi2WO6/EP photocatalyst, rGO QDs-Bi-Bi2WO6 was successfully immobilized as superior-active photocatalyst component and the selection of EP was retainable price sustainable support and recyclability of the designed photocatalyst. The as-fabricated nanocomposites were comprehensively characterized by spectroscopic techniques and electrochemical reaction. The photocatalytic degradation performances of rGO QDs-Bi-Bi2WO6/EP nanocomposite was evaluated evidently by the degradation of hazardous organic contaminants (RhB and phenol) with high rate constants k of 0.23 min−1 and 0.047 min−1, respectively, under sun-like irradiation. The obviously enhanced photocatalytic efficacy of rGO QDs-Bi-Bi2WO6/EP should be attributed to uniform dispersion and floating behavior of the well-designed photocatalyst owing to enhanced visible-light absorption, photocurrent and high transfer efficiency of photoinduced electron-hole pairs due to close intimated contact between rGO QDs and Bi-Bi2WO6/EP.
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•Fabrication of rGO QDs-Bi-Bi2WO6/EP floating photocatalysts using Expanded Perlite (EP) as a sustainable support•The photocatalytic efficiency of rGO QDs-Bi-Bi2WO6/EP nanocomposite was evaluated by degradation of organic contaminants under sun-like irradiations•rGO QDs-Bi-Bi2WO6/EP nanocomposite is floating material and easy to separate from water system
Abstract
It appears that the biologically-synthesized nanoparticles (NPs) have potential to perform as effective elicitors for the production of valuable secondary metabolites in plants. Besides, it ...has been reported that the toxicity of the biologically-synthesized NP is not as much as that of the chemically-synthesized NPs. Therefore, it is necessary to test their advantages aspects. In this study, the physical synthesis of perlite NPs and biologically-synthesis of TiO
2
/perlite nanocomposites (NCs) were conducted. Subsequently, their effects and explant source influence on the growth characteristics and secondary metabolite profiles of
Hypericum perforatum
callus cultures were evaluated. According to the obtained results, morphology of the synthesized perlite NPs and TiO
2
/perlite NCs were mesoporous and spherical with sizes ranging about 14.51–23.34 and 15.50–24.61 nm, respectively. Addition of perlite NPs and TiO
2
/perlite NCs to the culture medium at the concentration range of 25–200 mg/L showed no adverse impacts on the growth characteristics of
H. perforatum
calli. According to the GC-MS analysis, the stress caused by perlite NPs and TiO
2
/perlite NCs led to an increase in the variety, amount and number of volatile compounds. The calli obtained from
in vitro
grown plants produced more volatile compounds relative to the calli obtained from field grown plants under the nanomaterial stress conditions. The production of hypericin and pseudohypericin were also determined in the callus cultures under desired nanomaterials elicitation. Accordingly, our results suggest that perlite NPs and TiO
2
/perlite NCs can possibly be considered as effective elicitors for the production of volatile compounds, hypericin, and pseudohypericin in callus cultures of
H. perforatum
.
•Paraffin and different surface treated expanded perlite composites were fabricated.•Hydrophobic expanded perlite composite PCM prevents the PCM leakage.•The PCM leakage was correlated with contact ...angle measurements of FS-PCM composites.
In this study, the feasibility of integrating form-stable phase change material (FS-PCM) composites into cementitious composites was investigated. Two different FS-PCM composites were fabricated by using paraffin as functional PCM and hydrophilic and hydrophobic expanded perlite as supporting materials. Because of different surface treatment properties of expanded perlite (EP), their behavior in the cementitious composites were found to be different. Paraffin/hydrophilic EP showed a significant amount of PCM leakage during the integration into cementitious composites. However, no trace of PCM leakage was observed when paraffin/hydrophobic EP integrated into cementitious composites. The instability of FS-PCM in cementitious composite was correlated with surface characteristics of composite PCMs such as contact angle and wetting tension properties. It has been found that the composite PCM having contact angle higher than 90° and negative wetting tension properties successfully prevents the PCM leakage in cementitious composites due to counter-water affinity properties.
•Paraffin has good compatibility with expanded perlite.•The optimal cement of paraffin/expanded perlite materials in cement mortar is determined as 20wt%.•The heat storage/release curves of cement ...mortar with paraffin/expanded perlite materials changed slightly after 100 cycles.•Cement mortar with 20wt% paraffin/expanded perlite materials has good heat storage and thermal stability.
In this study, cement mortar with paraffin/expanded perlite materials was prepared by direct mixing method. The effect of paraffin/expanded perlite material content on mechanical and thermal properties of cement mortar were investigated. The experimental results showed that the paraffin was confined in the porous structures of expanded perlite by capillary force. The average mass percentages of paraffin in paraffin/expanded perlite material reached as high as 65%. It was a physical interaction between paraffin and expanded perlite. Compressive strength and flexural strength of cement mortar decreased with increasing amount of paraffin/expanded perlite materials. Cement mortar with 20wt% paraffin/expanded perlite materials had good heat storage property and thermal stability compared to ordinary cement mortar.
Magnolia sirindhorniae Noot. & Chalermglin is an endangered species with high ornamental and commercial value that needs to be urgently protected and judiciously commercialized. In this study, a ...protocol for efficient regeneration of this species is standardized. The lateral buds of the M. sirindhorniae plant were used as an explant. Half-strength Murashige and Skoog (MS) medium supplemented with 2.0 mg/L 6-benzyladenine (BA), 0.1 mg/L α-naphthaleneacetic acid (NAA), and 2.0 mg/L gibberellic acid (GA
) was found to be the optimal medium for shoot induction. The maximum shoot multiplication rate (310%) was obtained on Douglas-fir cotyledon revised medium (DCR) fortified with 0.2 mg/L BA, 0.01 mg/L NAA, and additives. The half-strength DCR medium supplemented with 0.5 mg/L NAA and 0.5 mg/L indole-3-butyric acid (IBA) supported the maximum rate (85.0%) of in vitro root induction. After a simple acclimatization process, the survival rate of plantlets in a substrate mixture of sterile perlite and peat soil (1:3; v/v) was 90.2%. DNA markers were used for assessment of genetic uniformity, confirming the genetic uniformity and stability of regenerated plants of M. sirindhorniae. Thus, the described protocol can safely be applied for large scale propagation of this imperative plant.
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•A thermal render with cement-fly ash, subcritical hybrid aerogel and co-aggregates.•T1 thermal render with suitable compressive strength and good deformation capacity.•The ...lightweight aggregates mixture enhances hygrothermal and mechanical performance.•Correlation between molecular and pore structure and performance.
The role of lightweight aggregates on the hygrothermal and mechanical performance of cementitious aerogel-based renders was understood. The lightweight aggregates totally replaced silica sand, with a binder:aggregate volume ratio of 1:4. A cement-fly ash (50wt%) binder, with 60vol% subcritical silica-based aerogel, 20vol% granular expanded cork, 15vol% expanded clay and 5vol% perlite, produces a lightweight (652kg.m−3), thermal render (thermal conductivity of 0.084W.m−1.K−1), with acceptable mechanical strength and good deformation capacity. The correlation of these renders’ properties with the molecular and pore structure of the aggregates proved to be extremely useful to improve their overall performance.
In this study, the fatty acid eutectics (capric acid (CA) and lauric acid (LA) eutectics) were impregnated into the expanded perlite (EP) and expanded vermiculite (EVM) to form the two kinds of ...composite phase change material (PCM). The chemical structure, crystalloid phase were determined by the Fourier transformation infrared spectroscope, X-ray diffractometer. The results show that the eutectics with the EP and EVM do not undergo a chemical reaction and only undergo a physical combination. The SEM results proved that eutectics are well adsorbed in the porous structure of the EP and EVM. The thermal properties were determined by the differential scanning calorimeter (DSC). The DSC result shows that the melting temperatures and latent heat values of the PCMs are in the range of about 21–23°C and 81–117J/g. The maximum impregnation ratio of fatty acid eutectics into EP and EVM were 82.93% and 57.48%. The thermal cycling test proves that the composites have good thermal reliability. TG analysis revealed that the composite PCMs had high thermal durability property above their working temperature ranges. Besides, thermal conductivity of the CA-LA/EP and CA-LA/EVM was increased approximately as 89.14% and 87.41% by adding 5wt.% expanded graphite (EG). It is envisioned that the prepared shape-stabilized PCMs have considerable potential for developing their roles in thermal energy storage system.
Perlite and vermiculite are commonly used aggregates for lightweight gypsums, but they cause negative environmental impacts due to the high energy demand needed during their manufacture. Therefore, ...this paper studies the physical and mechanical behavior of lightweight gypsums using incorporating mixes of polystyrene wastes, both extruded (XPS) and expanded (EPS) polystyrene, in order to substitute perlite and vermiculite and achieve new materials complying with circular economy criteria. For this, and experimental plan was designed and 33 series of gypsums were prepared containing different percentages of EPS and XPS waste and also reference samples (with no additions). These samples were tested in the laboratory and the following tests were developed: dry density, superficial hardness, mechanical strengths and thermal behavior. A comparative analysis evidenced that it is viable to obtain lightweight gypsum when adding mixes of XPS and EPS waste. These gypsums containing polystyrenes comply with the current standards and have lower density than currently used lightweight gypsums and similar mechanical strengths.
Expanded perlite is a valuable lightweight material for building materials industry as well as for agriculture, horticulture etc. Unfortunately during both production as well as processing of ...expanded perlite, some fine grained waste perlite is being formed. Due to its extremely low bulk density waste expanded perlite is difficult to handle, utilize and causes dust formation. Paper presents method of utilization of waste expanded perlite as a valuable, high performance pozzolanic supplementary cementitious material. Waste expanded perlite was ground in ball mill in order to destroy cellular microstructure of waste expanded perlite. It resulted in significant increase in specific surface area of material. Results of strength tests showed, that addition of ground waste expanded perlite may result in strength gain up to 50% (for 35% addition in respect to cement mass). Due to its high activity ground waste expanded perlite can be used as both cement substitute as well as cement additive depending on desired properties of final material. Investigations showed, that ground waste expanded perlite is material of pozzolanic activity. Except strength test, pozzolanic activity was investigated by solubility test according to ASTM C379-65T. Direct measurements of calcium hydroxide content in hydrating alite pastes confirmed that ground expanded perlite reacts with calcium hydroxide what results in reduction of calcium hydroxide content in alite paste. Pozzolanic activity of ground waste expanded perlite was compared with commonly used commercial pozzolanas. Obtained results allow to classify ground waste expanded perlite as material of pozzolanic properties. It can be valuable supplementary cementitous material mainly for special applications due to its high pozzolanic activity and very bright, almost white colour. In addition to that, ground waste expanded perlite used as cement replacement allows to decrease carbon dioxide emission, since Portland cement manufacturing is connected with emission of considerable amount of carbon dioxide.
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