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This present study investigated the adsorption characteristics of rock melon skin (RMS) as a promising adsorbent for the removal of toxic brilliant green (BG) dye. The functional group and surface ...

This study investigates the possibility of enhancing Artocarpus odoratissimus leaves (TL) through surface modification with a base, NaOH (TLN), a surfactant, SDS (TLS) and a chelating agent, EDTA (...

Ipomoea aquatica (IA) was investigated for its potential as a low-cost adsorbent to remove toxic methyl violet 2B (MV2B) dye in aqueous solutions. Optimising parameters such as the effects of contact time, medium pH and ionic strength (using NaCl, NaNO3, KCl and KNO3) were investigated. The results indicated that 150 min were sufficient for the adsorption to reach an equilibrium state and no adjustment of pH medium was necessary. Batch adsorption experiments such as adsorption isotherm, thermodynamics and kinetics were investigated and the experimental isotherm data were fitted to six isotherm models, namely Langmuir, Freundlich, Temkin, Dubinin-Radushkevich, Redlich-Peterson and Sips, with the latter being the best-fit isotherm model showing maximum adsorption capacity (qmax) of 267.9 mg g−1. Thermodynamics studies indicated adsorption of MV2B to be exothermic in nature, occurring spontaneously. The kinetics was best described by the pseudo-second-order model. Regeneration of IA pointed to its reusability, maintaining high adsorption capacity even up until Cycle 5 when treated with acid (HCl) and base (NaOH). Functional groups such as hydroxyl and amine groups which could be involved in the adsorption of MV2B were determined using FTIR spectroscopy, and the point of zero charge of IA was found to be at pH 6.81.

A tropical wild fern, Diplazium esculentum, locally known as Pakis, was investigated in this study as a low-cost adsorbent for the removal of toxic crystal violet (CV) dye. The adsorbent–adsorbate system reached equilibrium in 180 min and data obtained from batch adsorption experiment were best fitted with the Sips isotherm model. High maximum adsorption capacity (qmax) of 350.86 mg/g compared to many other reported adsorbents revealed the potential of this fern as a low-cost, new adsorbent for the removal of CV. Adsorption mechanism followed the pseudo second-order kinetics. Another attractive feature is its ability to be regenerated and reused, especially when using the base treatment, while maintaining high adsorption of >96% even at the fifth consecutive cycles.

Etlingera species are widely used traditionally as cooking herbs for their medicinal properties and also used as cosmetics by different ethnic communities in Borneo. This study investigated the bioactive potential of methanolic extracts of leaves, stems and rhizomes of Etlingera fimbriobracteata. Standard methods were applied to detect the presence of phytochemicals and to determine the phenolic content in methanolic extracts of leaves, stems and rhizomes of E. fimbriobracteata. Plant extracts were subjected to antioxidant (DPPH, ABTS, reducing power assay, ferric-reducing antioxidant power and total antioxidant capacity) and antimicrobial (disc diffusion) evaluations. Antidiabetic (for 4 weeks using Wistar rats) and anticancer (MTT assay) activities were also determined for leaves extract of E. fimbriobracteata. Phytochemicals screening revealed the presence of steroids, cardiac glycosides and saponins. Leaves extract showed the highest amount of polyphenolic compounds and antioxidant activity than those of stems and rhizomes. A significant correlation (p

As an extension to successful adsorption of malachite green dye onto Artocarpus odoratissimus (Tarap) leaves, the surface of the leaves was modified by using a strong base, namely sodium hydroxide (NaOH). The isotherm was best fitted to the Redlich–Peterson model. Based on monolayer adsorption using Langmuir model, the q m a x value of Tarap leaves enhanced from 254.9 to 422.0 mg/g upon the modification, and increased by 3 fold when using the Sips model. This paper provided a better insight on the types of reactions that occurred during the adsorption process and the strength of attractions between adsorbent–adsorbate supported with the aid of multiple characterization methods. Other influencing parameters on adsorption such as contact time, ionic strength, pH, temperature and initial dye concentrations were also studied.

In this study, a simple chemical modification was applied to a sustainable and abundantly available resource, kangkong root (KR), to remove methyl violet 2B (MV) dye. The chemically modified adsorbent (NaOH-KR) was obtained using NaOH solution treatment. Batch adsorption experiments were carried out to investigate the effects of pH, ionic strength, contact time, adsorbent dosage, and initial dye concentration. A regeneration experiment was also carried out to assess the potential of reusability. The adsorption process was modelled using various kinetics and isotherm models, whereby the best-fitting models were evaluated by using the coefficient of determination ( R 2 ) and error functions. The Sips ( R 2 = 0.9714 , χ2 =0.16) and pseudo-second-order ( R 2 = 0.9996 , χ 2 = 0.007 ) models were identified to best represent the adsorption process. The Sips model predicted a maximum adsorption capacity at 551.5 mg g-1 for NaOH-KR, which is 55% improvement in performance when compared to nonmodified KR. Lastly, the regeneration experiment showed that NaOH-KR was able to maintain reasonable dye removal even after five consecutive cycles of regenerating and reusing.

Development of efficient and environmentally friendly methods to remove toxic pollutants from aqueous systems is a requirement to mitigate ever increasing environmental pollution problems. In this context, Artocarpus altilis (breadfruit) peel (BP), a waste material, can be used as a low-cost adsorbent for the removal of Pb(II) ions from synthetic pollutant solutions. The extent of removal of Pb(II), under optimized conditions in experimental batch experiments, is determined to be 82.0%, which is decreased in highly ionic environments, partly due to competition for a limited number of active adsorption sites, indicating the necessity of optimizing experimental parameters for the most efficient removal. Regression analysis and error function values evaluated for isotherm models associated with different adsorption mechanisms, namely Langmuir, Freundlich, Temkin, Dubinin–Radushkevich, Redlich–Peterson and Sips, indicate that the best fitted model is the Sips followed by the Langmuir model with adsorption capacities (qmax) of 78.50 mg g−1 and 85.42 mg g−1, respectively. Thermodynamics arguments support the spontaneous and exothermic behavior of the Pb(II)-BP adsorption system, while adsorption kinetics of the system provides evidence for the applicability of the pseudo second order model with a rate constant of 0.504 g mg−1 min−1.

Leaves of Artocarpus odoratissimus have successfully undergone surface chemical modification using a base (NaOH) and a chelating agent (EDTA) via a single and double modification. The modified adsorbents were investigated for their potential use in adsorbing Pb(II) from simulated wastewater and were tested through several adsorption parameters such as pH, ionic strength, interference effect, regeneration and column (dynamic) studies. The adsorption of Pb(II) by the adsorbents was excellent where the removal of Pb(II) was almost resilient to change of pH, except at pH 2, and unaffected by the presence of other metal ions. Further, the adsorbents can be regenerated using acid and base, maintaining good adsorption even at the 4th cycle. The dynamic study concluded that column containing higher bed heights of the adsorbent took more time to exhaust and able to adsorb more volume of the Pb(II). Adsorption isotherm data point to double modified adsorbent has higher adsorption capacity than the untreated and single modified adsorbents. This study also showed that the kinetics of all the adsorbents was following pseudo-second order indicating that the adsorption processes were all chemisorption.

The present study investigates the use of cheap, readily available natural adsorbent, Artocarpus odoratissimus leaves (TL), for the removal of toxic rhodamine B (RhB) dye from simulated wastewater. TL showed resilience when tested in a wide range of pH and was able to maintain its adsorption capacity with the highest removal of RhB at pH 3. Investigation of the effect of ionic strength was carried out using four different salts, namely $$\hbox {KNO}_{3}$$ , NaCl, $$\hbox {NaNO}_{3}$$ and KCl. Of these, only $$\hbox {KNO}_{3}$$ influenced the removal of RhB dye, while the other three salts did not show any significant effect. Maximum adsorption capacity, $$q_{\max }$$ , of 104.96 mg/g was based on the Langmuir isotherm being the best fit model with highest $$R^{2}$$ value close to unity and lowest error values. Adsorption mechanism followed the pseudo second-order kinetics with rate constant $$k_{2}$$ of 1.274 and 0.616 g/mmol min using 100 and 500 mg/L dye, respectively. Regeneration studies confirmed TL can be regenerated and reused thereby adding value to TL as a potential adsorbent in remediation of dye wastewater. SEM and FTIR were used to characterize the adsorption of RhB onto TL.

Cellulose from the leaves of Artocarpus odoratissimus has been successfully extracted for application as a potential low cost and effective adsorbent to remove toxic dyes, including methyl violet (MV) and crystal violet (CV), from aqueous solution. The adsorption isotherm and kinetics of MV and CV were evaluated in detail. We found that the both dyes were effectively adsorbed by the extracted cellulose with the maximum adsorption capacity was as high as 187 and 239 mg/g for MV and CV, respectively. The adsorption mechanism was governed by the pseudo second-order kinetics, indicating that the attachment of dyes on the extracted cellulose was due to the presence of strong chemical interactions bonds owing to electrostatic attractions. This is supported by regeneration study where the spent adsorbents were effectively regenerated only by using acid and base. In addition, we also demonstrated that the adsorption process involved intraparticle diffusion and hydrogen bonding interactions, thus it depended on pH and ionic strength of the medium. With the high adsorption capacity to remove dyes from aqueous solution, the extracted cellulose would be potentially applicable for treating contaminated wastewater.

Tarap peel (TP) and oxalic-acid-modified Tarap peel (TP-OX) were used to remove brilliant green (BG) dye from aqueous solution. Surface modification of TP suggested that functional groups such as carboxyl, hydroxyl and amino were involved in the adsorption of BG onto TP. Parameters such as effects of pH, contact time, ionic strength, initial dye concentration and temperature were included to study the adsorption of BG onto TP and TP-OX. Adsorption isotherm models were used to investigate the adsorption process, while kinetics models were used to provide insight into the adsorption mechanisms. Optimised contact time of 2 h with no pH adjustment was used. Adsorption of BG onto TP was best fitted to the Freundlich model, while experimental data for TP-OX are best described by the Tempkin model. The maximum adsorption capacities were determined as 174 and 275 mg g−1 for TP and TP-OX, respectively. Thermodynamics study indicated the endothermic nature of adsorptions of BG onto both adsorbents. According to kinetics study, the adsorption mechanisms on both adsorbents followed pseudo-second-order model, and film diffusion might have major role in the adsorption process.

This study reported Nepenthes rafflesiana pitcher (NP) and Nepenthes rafflesiana leaves (NL) as new adsorbents for methyl violet (MV) dye. The experiments were done using 2 h contact time and without any pH alteration (pH 4.4). The effects of pH and ionic strength revealed hydrophobic–hydrophobic interaction as the predominant force of dye interaction with the adsorbent. Both NP-MV and NL-MV followed pseudo-second-order model indicating the adsorption processes may be governed by chemical process. Weber–Morris intraparticle diffusion model verified that the rate-limiting step of both the NP-MV and NL-MV systems is not intraparticle diffusion. The Langmuir model best described the adsorption process with high maximum monolayer adsorption (q m) of 288.7 and 194.0 mg g−1 for NP-MV and NL-MV, respectively. Thermodynamics studies revealed both NP-MV and NL-MV systems are spontaneous and endothermic in nature. From the regeneration study, it was found that NP’s and NL’s adsorption capacities could be recovered using distilled water and base whereby distilled water was able to recover 78% (NP) and 71% (NL) while base was able to recover 82% for both samples after three regeneration cycles.

Forty-five volatile organic compounds (VOCs) were identified or annotated in the mandibular gland reservoir content (MGRC) of the Southeast Asian ant Colobopsis explodens Laciny and Zettel, 2018 (Hymenoptera: Formicidae), using headspace solid-phase microextraction (HS-SPME) coupled to gas chromatography-mass spectrometry (GC-MS) and liquid extraction combined with GC-MS. In extension of previous reports on VOCs of C. explodens, members of different compound classes, such as alkanes, aliphatic and aromatic carboxylic acids, and phenolics, were detected. The ketone 2-heptanone and the biochemically related phenolics benzene-1,3,5-triol (phloroglucinol, PG), 1-(2,4,6-trihydroxyphenyl)ethanone (monoacetylphloroglucinol, MAPG), 5,7-dihydroxy-2-methylchromen-4-one (noreugenin), and 1-(3-Acetyl-2,4,6-trihydroxyphenyl)ethanone (2,4-diacetylphloroglucinol, DAPG) dominated the GC-MS chromatograms. The identities of the main phenolics MAPG and noreugenin were further verified by liquid chromatography-high resolution-tandem mass spectrometry (LC-HRMS/MS). A comparative study of MGRC samples originating from three distinct field expeditions revealed differences in the VOC profiles, but the presence and relative abundances of the dominating constituents were largely consistent in all samples. Our study considerably extends the knowledge about the number and type of VOCs occurring in the MGRC of C. explodens. Based on the type of the detected compounds, we propose that the likely irritant and antibiotic phenolic constituents play a role in defense against arthropod opponents or in protection against microbial pathogens.

Natural dyes from Ixora coccinea (RX) and Bougainvillea sp. (BG) were extracted and these individual dyes as well as the cocktail dye of RX and BG (1:1 v/v ratio) were investigated as dye sensitizers in dye sensitized solar cells (DSSCs). To analyze the capability of the dyes, various characterization methods were deployed such as incident photon-to-current efficiency (IPCE), current-to-voltage (I-V) characteristics, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). It was found that DSSC sensitized with RX performed the best with η = 0.76%, followed by the cocktail dye (η = 0.40%) and BG (η = 0.21%). This best overall performance of RX was attributed to the charge transport resistance (Rtr = 3.89 Ω), with the highest electron density (ɳs = 9.45 × 1028) and effective diffusion coefficient (Deff = 2.43 × 10− 8 m2/s), which accounted for high Jsc. Co-dominance performance of DSSC sensitized with cocktail dye was observed where the cocktail dye has demonstrated an improved Voc as compared to RX and improved Jsc against BG, suggesting individual influence from both dyes.

This study presents Ipomoea aquatica root (“kangkong” root or KR) as a plausible environmentally friendly adsorbent. This readily available adsorbent, after oven drying, demonstrates strong adsorption characteristics toward Auramine O (AO) dye exhibiting 2.0 h equilibration time and stable efficiency within a sufficiently broad range in both pH and ionic strength. Adsorption kinetics was best described by the pseudo second order and Elovich models, indicating that chemisorption of two reactive moieties could be involved. Application of the experimentally obtained adsorption equilibrium data to investigate the conformity among many adsorption isotherm models, namely Langmuir, Freundlich, Temkin, Redlich-Peterson and Sips, together with corresponding error analyses, identified that the Sips model be the best-fit model, leading to attractive maximum adsorption capacity of 455.74 mg g−1. Further, regeneration and reuse of the spent adsorbent would be possible with ~ 75% AO dye being adsorbed even at the 5th cycle, when using base treatment. Hence, the utilization of Ipomoea aquatica root as a low-cost, effective adsorbent in wastewater treatment could be possible.

The main objective of this study is to investigate the ability of Nephelium mutabile (Pulasan) leaves (PL) in removing toxic brilliant green (BG) dye using the adsorption method. Batch experiments were conducted on the adsorption of BG dye using PL with a contact time of 3.5 h. Adsorption isotherm studies were analysed using six isotherm models, namely Langmuir, Freundlich, Temkin, Dubinin-Radushkevich (D-R), Redlich-Peterson (R-P) and Sips, and the results showed that Sips is the model that best fits the experimental data, with a maximum adsorption capacity (amax) of 130.3 mg g-1. The point of zero charge (pHPZC) of PL was found to be at pH 5.29. Regeneration studies showed that PL can be recovered and reused, especially after treatment with NaOH. This study demonstrates that PL can be considered as a reasonably good and cost-effective biosorbent for BG under our experimental conditions.

The aim of this manuscript is to present a protocol describing the metabolomic analysis of Bornean 'exploding ants' belonging to the Colobopsis cylindrica (COCY) group. For this purpose, the model species C. explodens is used. Ants belonging to the minor worker caste possess distinctive hypertrophied mandibular glands (MGs). In territorial combat, they use the viscous contents of their enlarged mandibular gland reservoirs (MGRs) to kill rival arthropods in characteristic suicidal 'explosions' by voluntary rupture of the gastral integument (autothysis). We show the dissection of worker ants of this species for the isolation of the gastral portion of the wax-like MGR contents as well as listing the necessary steps required for solvent-extraction of the therein contained volatile compounds with subsequent gas chromatography-mass spectrometry (GC-MS) analysis and putative identification of metabolites contained in the extract. The dissection procedure is performed under cooled conditions and without the use of any dissection buffer solution to minimize the changes in the chemical composition of the MGR contents. After solvent-based extraction of volatile metabolites contained therein, the necessary steps for analyzing the samples via liquid-injection-GC-MS are presented. Lastly, data processing and putative metabolite identification with the use of the open-source software MetaboliteDetector is shown. With this approach, the profiling and identification of volatile metabolites in MGRs of ants belonging to the COCY group via GC-MS and the MetaboliteDetector software become possible.

This study focused on the adsorption characteristics of jackfruit seed as an adsorbent for the removal of malachite green (MG) dye from aqueous solution via batch adsorption experiment. The performance of the adsorbent was investigated through several parameters, namely contact time, pH, dye concentration, ionic strength and temperature. Adsorption of MG by jackfruit seed required 2 h to reach equilibrium and was found to be sensitive to the pH medium, but relatively unaffected by ionic strength. The Langmuir, Freundlich and Sips isotherm models were used to describe the adsorption process, while the Lagergren first-order, pseudo-second-order and Weber–Morris intraparticle diffusion models were used to predict the adsorption mechanism. The Freundlich model was found to best fit the experimental data, and the maximum monolayer capacity (from Langmuir model) was determined as 66 mg g−1. The kinetics mechanism followed pseudo-second-order model and intraparticle diffusion was found not to be the rate-determining step. In addition, machine learning models such as artificial neural network and random forest were used as predictive models for the adsorption process where high R values of 0.966 and 0.981, respectively, and low RMSE of 0.048 and 0.038 were obtained. This study concludes that jackfruit seed has the potential to be used as a low-cost adsorbent for the removal of toxic MG dye.

Three plant-based materials, namely water lettuce (WL), tarap peel (TP) and cempedak peel (CP), were used to investigate their potentials as adsorbents using acid blue 25 (AB25) dye as a model for acidic dye. The adsorbents were characterised using Fourier transform infrared spectroscopy, X-ray fluorescence and scanning electron microscope. Batch experiments involving parameters such as pH, temperature, contact time, and initial dye concentration were done to investigate the optimal conditions for the adsorption of AB25 onto the adsorbents. Thermodynamics study showed that the uptake of AB25 by the three adsorbents was feasible and endothermic in nature. Both the Langmuir and Freundlich isotherm models can be used to describe the adsorption process of AB25 onto WL and CP while pseudo-second-order fitted the kinetics data, suggesting that chemisorptions were majorly involved. The use of 0.1 M of NaOH showed the best results in regenerating of the WL, TP and CP’s adsorption ability after AB25 treatment.

The purpose of this research is to investigate biosorption characteristics of two cationic dyes, methylene blue (MB) and methyl violet 2B (MV), on breadfruit (Artocarpus altilis) peel and core. Characterization of breadfruit waste was conducted using surface titrations, thermogravimetry, and Fourier transform infrared spectroscopy. The extent of interaction between dyes and each biosorbent was monitored by absorbance measurements, which was then used in isotherm, thermodynamics, and kinetics analysis. Biosorption of MB and MV on breadfruit peel and core reaches equilibrium in 150–180 min. All four systems under investigation (MB-breadfruit peel, MB-breadfruit core, MV-breadfruit peel, and MV-breadfruit core) show similar extent of dye removal of about 80% under the conditions employed. Biosorption of both dyes on both biosorbents follow the Langmuir adsorption isotherm model at the ambient pH, at which the breadfruit surface bears a negative charge. Kinetics of biosorption of MB on breadfruit waste is so fast that it is not possible to determine the order of adsorption kinetics at the concentration level employed. The rate of biosorption of MV on breadfruit waste is smaller and follows pseudo second order kinetics with rate constants of 153.5 and 31.7 g mmol−1 min−1 for peel and core, respectively. Thermodynamics studies conducted for each biosorption system provide negative ΔG Θ, ΔH Θ and ΔS Θ values with the maximum biosorption for MB at the ambient temperature of 24 °C, while that for MV is obtained between 40 and 50 °C. All four biosorption systems show spontaneity and exothermic behaviour to varying degrees.

In this study, the peat samples from two different sites of Brunei Darussalam (Mumong and Panaga) were investigated. The peats were found to be acidic in nature containing 66–75% organic matter. Thermogravimetric analysis revealed their thermal stability up to 500°C, while scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray fluorescence provided information on the modes of interaction of Cu(II) ions with peat through complexation and ion-exchange mechanisms. Further, the extent of removal of Cu(II) ions from aqueous solution investigated under different experimental conditions revealed that the optimum values for shaking time and medium pH were 3.0 h and 5.5, respectively. Equilibrium adsorption data fitted to the Langmuir, Freundlich, Temkin, Dubinin–Radushkevich (D–R), Redlich–Peterson (R–P), and Sips isotherm models indicated that adsorption of Cu(II) ions on peat obeyed the Sips model with an average adsorption capacity of 16.5 and 14.6 mg g−1 for the Mumong and Pa...

Azolla pinnata (AP) and soya bean waste (SBW) were studied for their potentials to remove hazardous dye, acid blue 25 (AB25), from aqueous solution in a batch adsorption process. Various parameters such as pH, contact time, concentration and temperature were studied. The optimum pH was found to be at pH 2.0, and short duration of contact time at 180 min was sufficient to attain equilibrium. The experimental data were fitted to three different isotherm models, and the adsorption was best described by the Langmuir isotherm model. The maximum monolayer capacities were estimated to be 38.3 and \({50.5\,{\rm mg}\,{\rm g}^{-1}}\) for SBW and AP, respectively. Kinetics studies showed that the adsorption system for both adsorbents follow pseudo-second-order model. Weber–Morris model showed that intraparticle diffusion is not the rate-limiting step, while Boyd model suggested that film diffusion may be the controlling mechanism for both adsorbent. The adsorption processes were found to be thermodynamically feasible. AP-AB25 system is endothermic in nature, while SBW-AB25 is exothermic. Regeneration experiment showed that NaOH is effective at regenerating the spent adsorbent, where at fifth cycle, the adsorption capacities of AP and SBW were comparable to the unspent adsorbents. All of these discoveries highlighted the potential of both AP and SBW as effective adsorbents for removal of AB25.

This paper aims to investigate the potential use of cempedak durian peel (CDP) from Negara Brunei Darussalam, which is low-cost, locally available, eco-friendly and highly efficient to remove methyl violet (MV) dye from aqueous solutions. The time required for equilibrium to be reached is 2.0 h with no adjustment of pH necessary. FTIR analysis was indicative of the involvement of -COOH and C=O functional groups in adsorption process. The Langmuir model provided the best fit with maximum adsorption capacity of 0.606 mmol g -1 . Thermodynamics data indicate that the adsorption is spontaneous, feasible and endothermic in nature. Best regeneration of CDP's adsorption ability is achieved by base solution, showing about 95% removal efficiency of MV even after 5 cycles, indicating that CDP can be regenerated and reused. This, together with its high adsorption capacity, makes CDP a potential adsorbent for the removal of MV in wastewater.

Peat, being a partially decomposed organic material, consists of many organic compounds, such as humic acids and fulvic acids, which contain phenolic, carboxylic acid and amino functionalities, contributing to unique surface characteristics. Firing of peat leads to the loss of organic matter, thus changing the point of zero charge and controlling the extent of adsorption. The change in the initial pH of Cr(VI) solutions does not significantly change the pH of the suspension of Muthurajawela peat (MP) materials and Cr(VI) solutions, maintaining a constant extent of removal. The optimum conditions for the removal of Cr(VI) are 2.0 h shaking time, 1.0 h settling time, 200°C firing temperature and an ambient pH of 3.8–4.2, leading to a high extent of removal of 120 mg kg−1. The sorption of Cr(VI) on MP fulfills the requirements of the Freundlich adsorption model with a high regression coefficient. Further, the sorption of Cr(VI) on peat is a pseudo-second-order process at moderate solution temperatures.

Cuscuta species (dodders) are widespread stem holoparasites that depend on host plants for their entire mineral and water and most carbohydrate requirements. Dodders negatively affect host photosynthesis but precise information on their impact on hosts in the presence of environmental stress factors (i.e. drought) is little known. In a pot experiment, the leaf traits, gas exchange and chlorophyll a fluorescence of the invasive climber, Mikania micrantha, parasitized by Cuscuta australis, were investigated in order to study variations of host photosynthesis in response to parasitism and drought. The results showed that the concomitant presence of C. australis infection and drought significantly impacted the leaf traits (i.e. increased leaf dry mass content), gas exchange (i.e. decreased stomatal conductance and transpiration rates and increased water-use efficiency) and quantum yield of chlorophyll a fluorescence of M. micrantha. The presence of a single stress factor (C. australis infection or drought), however, only significantly affected the leaf traits and gas exchange of M. micrantha. These results suggested that the combined additive effects of C. australis parasitism and drought significantly suppressed the photosynthesis of M. micrantha in relation to both stomatal and non-stomatal limitation of host photosynthesis. This study provides insights into Cuscuta–host interactions under drought conditions in the tropics.

Tropical fruit waste, breadfruit skin (BS), demonstrates great potential as a low-cost adsorbent for the removal of toxic malachite green (MG) dye. The optimum values of shaking time, settling time, and pH for the interaction of MG on BS are determined to be 3.5 h, 1 h, and pH 4.58, respectively. Further, adsorption of MG by BS is ionic strength dependent. Six isotherm models analyzed using adsorption equilibrium data indicate that the MG–BS adsorbate–adsorbent system can be best described by the Langmuir model with the maximum adsorption capacity (qmax) of 55.2 mg g−1, which is further confirmed by six different error functions. This adsorption system follows the pseudo-second-order kinetics, and the intraparticle diffusion could be the rate-determining step. Regeneration studies using NaOH washing illustrate the ability of BS to retain its high adsorption capacity of >90% even after 5 consecutive cycles. Column study reveals that more than 1,200 mL of 100 mg L−1 MG solution can be introduced to ...