Non-hazardous Nature Research Articles

Development of a Yeast-Based Assay for Bioavailable Phosphorus

ABSTRACT Preventing eutrophication of inland freshwater ecosystems requires quantifying the phosphorous (P) content of the streams and rivers that feed them. Typical methods for measuring P assess soluble reactive P (SRP) or total P (TP) and require expensive analytical techniques that produce hazardous waste. Here we present a novel method for measuring the more relevant bioavailable P (BAP); this assay utilizes the growth of familiar baker’s yeast, avoids production of hazardous waste, and reduces cost relative to measurements of SRP and TP. The yeast BAP (yBAP) assay takes advantage of the observation that yeast density at saturating growth increases linearly with provided P. We show that this relationship can be used to measure P in freshwater in concentration ranges relevant to eutrophication. In addition, we measured yBAP in water containing known amount of fertilizer and in samples from agricultural waterways. We observed that the majority of yBAP values were between those obtained from standard SRP and TP measurements, demonstrating that the assay is compatible with real-world settings. The cost-effective and nonhazardous nature of the yeast-based assay suggests that it could have utility in a range of settings, offering added insight to identify water systems at risk of eutrophication from excess phosphorus.

Antibacterial efficiency of naturally occurring dyes and mordants

The popularity of natural dyes is steadily increasing due to their properties such as soothing colors, non-carcinogenic & non-hazardous nature, and also being safe for the environment. Some natural dyes also have been reported to have antibacterial properties. This study was performed to explore the antibacterial efficiency of selected plant products that were used in the dyeing of fabric. Flowers of Butea monosperma and Tagetes erecta were used for the dye extraction. Banana pseudostem sap and Punica granatum rinds taken as biomordant. High-performance thin-layer chromatography was conducted for the identification of components of B. monosperma, T. erecta, Banana (Musa sp.) pseudostem sap and P. granatum rind. Dyeing of two types of cotton fabrics was performed at pre-optimized conditions. The antibacterial activities of dyed fabrics were evaluated qualitatively and quantitatively. Various phytochemical constituents in the dyeing plant materials already have antibacterial properties. Fabrics dyed with B. monosperma, T. erecta, Banana (Musa sp.) pseudostem sap and P. granatum rind showed high resistance towards Escherichia coli and Staphylococcus aureus.

Cobalt removal from an industrial effluent by foam fractionation

In this study, the removal of cobalt from an effluent was investigated probably for the first time by foam fractionation. Foam fractionation is considered as a green method because of its friendly nature, high removal efficiency, costs effectiveness and non-hazardous nature. Sodium dodecyl sulfate (SDS) was used as an anionic surface-active agent and the effect of gas flow rate, the initial concentrations of surfactant and cobalt and pH on the cobalt removal efficiency was investigated. The results showed that by increasing surfactant concentration and gas flow rate, the cobalt removal efficiency would be improved however, the cobalt concentration in foamate would decrease at high gas flow rates. High gas flow rates generally produce dilute foamate. Drainage of the interstitial bulk fluid that is entrapped between the foam bubbles has a key importance in the normal performance of the foam fractionation operation. Experiments showed that the well-drained foams are low in volume and high in Co2+ leading to an easier separation of their ingredients that usually follows. The efficiency reached the highest when cobalt feed concentration was about 1 mg/L, but dropped gradually in higher concentrations. By increasing pH to around 5, high removal efficiency was achieved and then decreased again. The optimum conditions for high cobalt removal efficiency were obtained when SDS concentration was about 100 mg/L and the initial cobalt concentration was below and close to 1 mg/L. The results of experiments revealed that the amount of cobalt removed per unit weight of SDS was higher for low [SDS]/[Co2+] ratios. They also showed that the air–liquid interface coverage by surface excess solute ions would not be more that 5% of the total area. Under optimum conditions for cobalt removal pH value and gas flow rate were found to be around 5 and 9 L/h, respectively. Under these conditions the removal efficiency was shown to be 99.4%.

Construction and performance of jarofix waste material embankment

Jarofix is a waste material generated during extraction of zinc from its ore. It is investigated for its feasibility in embankment road construction. For this, three 100 m long test embankments of jarofix, jarofix−soil and soil alone were constructed. The performance of finished road pavements constructed over these embankments was monitored for a period of 2 years by measuring different functional and structural parameters. To investigate the possibility of groundwater pollution, a leachate collection system was designed and installed below the embankment. The stiffness and failure stress of the jarofix−soil embankment were found to be higher than those of the jarofix embankment alone. The structural number (SN) estimated from deflection decreases with time, indicating a time-dependent deterioration of the pavement. The value of SN of the jarofix section was marginally lower than that of the soil section. The stress−settlement relationships of prototype embankments predicted from the measured test results on model embankments compared well with the actual stress−settlement relationships of the prototype embankments. Concentration of harmful constituents in the water leaching out of the jarofix embankment, namely, inorganic compounds and heavy metals, was insignificant, indicating the non-hazardous nature of the leachate water. Apart from cost saving, jarofix provides an alternative to conventional soil.

Assessment of Radioactivity and Radiological Hazard of Different Food Items Collected from Local Market in Bangladesh

Sixteen samples in three categories vegetables, cereals (rice, wheat, maize, pulse) and powdered milk were collected from local markets (Dhaka city) in Bangladesh and analyzed by using High Purity Germanium (HPGe) Detector for the assessment of natural and artificial radioactivity. In vegetables (potato, raw banana, giant taro, red amaranth), the average activity concentrations of 232Th, 226Ra, and 40K were found to be 37.82±11.57, 54.93±9.98 and 617.43±65.69 Bqkg-1 respectively, for cereals (rice, wheat, maize, pulse) 24.01±3.67, 31.46±4.00 and 474.83±27.68 Bqkg-1 respectively and for milk samples 15.01±3.65, 26.73±6.77 and 494.21±38.71 Bqkg-1 respectively. The average values of outdoor annual effective dose were found to be 92.18, 61.19 and 52.37μSvy-1 in vegetables, cereals and milk samples respectively. No artificial radionuclide was found in any of these samples. The average value of radium equivalent activity in all samples was 113.89 Bqkg-1 which was less than maximum permissible value 370 Bqkg-1. The values of external hazard indices for vegetables, cereals and milk samples varied from 0.31 to 0.66, 0.17 to 0.40 and 0.11 to 0.36 respectively which is less than unity in all samples that indicate the non-hazardous nature of the samples. The average values of annual effective ingestion dose rate from foods (for adult) were 274.33 μSvy-1, 533.60μSvy-1, and 132.73μSvy-1for 232Th, 226Ra and 40K respectively. These data would be useful to establish a baseline for natural radioactivity concentrations in food items consumed in Bangladesh.
 Journal of Bangladesh Academy of Sciences, Vol. 43, No. 2, 141-148, 2019

Performance Evaluation of Pavement Geomaterials Stabilized with Pond Ash and Brick Kiln Dust Using Advanced Cyclic Triaxial Testing.

An increase in the generation of industrial waste materials such as pond ash and brick kiln dust represents a serious threat to the earth’s environment. The waste materials have novel characteristics and therefore their physical, chemical, mineralogical, morphological, mechanical, and toxicity characteristics were determined so that these materials can be incorporated as construction materials based on technical and environmental considerations. The purpose of this study is to utilize the wastes in the stabilization of clay geomaterial to outperform existing problems of inadequate strength and stiffness of the subgrade layer in flexible pavements. Mixtures of geomaterials, containing pond ash, brick kiln dust, and their combination were prepared and important engineering characteristics such as the plasticity, compaction, and strength of the mixtures were examined. The measurement of response to dynamic loading is a pre-condition for the accurate characterization of geomaterials used in pavement construction. Using advanced cyclic triaxial testing, this study evaluates the performance of pond ash and brick kiln dust in increasing the stiffness of the geomaterial under cyclic loading. To stimulate the worst field conditions, the stiffness and strength tests were performed under standard and four-day water-soaked conditions. The implementation of several stress-dependent models for the prediction of stiffness was examined. Pond ash and brick kiln dust were found to be effective in increasing the stiffness and strength of the geomaterial. The wastes were the most effectual when added in combination to the geomaterial. The characterization of the wastes was informative in understanding the governing mechanism prevalent in the waste stabilized mixtures. The toxicity characterization study revealed the non-toxic and non-hazardous nature of the waste materials, permitting their use in the construction of pavements. This study recommends the use of wastes in the subgrade of flexible pavements. Further research is needed for performance evaluation of the wastes on silt and sand geomaterials for their wider application.

Pattern of Electroencephalography in Recurrent Febrile Seizure Patient

Background: Febrile seizures are seizures that often occur in children, usually of a non-hazardous nature and do not have a prolonged effect. Febrile seizures most often occur in children under five years of age and are reported to occur in 2-5% of the pediatric population. Febrile seizures are categorized as simple, complex and plus febrile seizures. In some patients, EEG is needed to ascertain whether a true febrile seizure occurs. Objective: This study aims to determine the EEG pattern in recurrent febrile seizure patients at the Child Inpatient Installation of Dr. Soetomo Surabaya. Method: This study used a retrospective descriptive method with medical record instruments. Results: This study showed that of 46 recurrent febrile seizures, only 21 patients could see the EEG results. Of the 18 patients with complicated febrile seizures there were 27.78% abnormal and 72.22% normal. One simple febrile seizure patient obtained a normal EEG result. Of the two patients with febrile seizures plus 50% abnormal results and 50% normal results. Conclusions: The EEG pattern in patients with recurring complex febrile seizure obtains the most abnormal result.
 
 Keywords: recurrent febrile seizure; electroencephalography; prevalence

Membrane Electrode Assembly with High Efficiency and Stability: Effect of Solvent Type and Membrane Composition

Membrane electrode assembly (MEA) method is being widely considered in proton exchange membrane fuel cell (PEMFC) preparation. This work describes for the first time how PEMFC performance can be enhanced, while using relatively low temperature processing for the MEA, by choosing the suitable solvent and suitable ionomer (nafion) content. Three dispersion solvents (water, ethylene glycol and ethanol) have been examined here, and ethanol (with lowest boiling point) showed best PEMFC performance. In addition to its non-hazardous nature, the low boiling point ethanol allowed manufacturing the working membrane at 130°C or lower besides using a safe solvent to use. In each solvent system, different nafion concentrations were used (10%, 20% and 30%). The 30% nafion concentration in ethanol showed highest performance (Open circuit potential of 0.88 V and output working potential of 0.67 V at 20 mA/cm2 current density) among the series. The anode and cathode, of the MEA, were both fabricated using same catalyst material (Platinum) and same nafion sheet thickness (50 μm). The spray method was employed. The electrochemical performance for the prepared MEA fuel cells was assessed by linear sweep voltammetry to evaluate the open circuit voltage.

Bioefficacy of Trichoderma as biological control agent against sugarcane wilt

Sugarcane is one of the most important cash crops grown in India. Diseases cause deterioration in the juice quality of infected canes and reduce extraction of sugar. Among the various diseases reported from India, wilt is important disease in sugarcane. The disease is soil as well as sett borne in nature. In recent years, the use of bio-pesticides has gained attention in the management of diseases because of their non-hazardous nature, easily biodegradable and also do not cause bioaccumulation. Some of the most potent isolates of Trichoderma spp. identified from study were tested in lab as well as field condition for disease management of wilt. In a field experiment it was observed that the wilt incidence in the susceptible variety CoLk 97169 was considerably reduced and yield was enhanced in soil application of Trichoderma (20 kg TMC/ha) followed by sett dipping in Trichoderma spore suspension (106 spores/ml) before planting. Trichoderma can be multiplied either on FYM or press mud for its incorporation in sugarcane fields for the management of wilt disease.

Room-Temperature Molten Salt for Facile Fabrication of Efficient and Stable Perovskite Solar Cells in Ambient Air

Summary Here, we report an alternative environmentally friendly room-temperature molten salt, methylammonium acetate (MAAc), as a novel solvent for facile fabrication of perovskite solar cells (PSCs) in ambient air. MAAc possesses excellent chemical properties along with high viscosity, negligible vapor pressure, and a nonhazardous nature. Complete solubility of both methylammonium and lead salts by hydrogen bonds in MAAc was observed. Dense and pinhole-free perovskite films with high reproducibility can be readily prepared by a simple one-step method without an anti-solvent even under a relative humidity of over 80%. Under optimized processing conditions, we achieved an average power conversion efficiency of 18.42% and a maximum efficiency of 20.05% in CH3NH3PbI3-based planar heterojunction structure. In addition, devices without encapsulation remained above 93% of their original efficiency for more than 1,000 h in ambient air. These findings may open up the possibility of developing a new approach for further improving PSC performance with higher reproducibility and reliability in ambient atmosphere.

Plant-Derived Edible Nanoparticles and miRNAs: Emerging Frontier for Therapeutics and Targeted Drug-Delivery

Rigorous and timely studies have been conducted to develop natural and green nanomedicines wherein plant-derived edible nanoparticles (PDENs) have a great potential to be applied for targeted therapeutic delivery systems, because of their exclusive characteristics, namely desirable nanoparticle morphologies, environmentally safe and nonhazardous nature, appropriate tissue-specific targeting, and eminent potential for industrial pharmaceutical production. These nanoparticles can be exploited for drug transportation with distinctive benefits for treatment of diseases like cancers. In this Perspective, the properties and applications of PDENs are discussed with latest developments including the recent trends in plant-derived edible exosome-like nanoparticles and miRNAs.

Offensive waste valorisation in the UK: Assessment of the potentials for absorbent hygiene product (AHP) recycling

Offensive human waste refers to non-hazardous waste that contains body fluids from non-infectious humans, comprised of post-consumer Absorbent Hygiene Products (AHPs), swabs, dressings, bedding, gloves, and other materials. While this waste category requires more stringent handling, storage and disposal measures than general waste, its non-hazardous nature suggests that there are opportunities for waste valorisation. An inventory of 200 offensive human waste bags collected from various healthcare institutions in South-Eastern England show that about 76% of the waste is comprised of AHPs, most of which are adult incontinence pads and child nappies. Mixed plastics comprised of predominantly HDPE represent 9% of the waste. To evaluate the potentials for offensive human waste valorisation, small-scale separation tests involving artificially-soiled nappies and associated mixed plastic packaging wastes have been performed. Findings suggest that about 50% of the total superabsorbent polymer is recoverable from fluff pulp fractions, recoveries of which are unaffected by the presence of ionic species typically present in human waste. On the other hand, recovery of mixed plastic packaging is more challenging. Overall, however, findings suggest that viable AHP recycling is possible if recyclate materials are targeted towards non-food related markets outlets such as the construction and land remediation sectors.

Experimental Study on Properties of Cellulose Fiber Concrete

The aim of this Project is to study the properties of cellulose fiber concrete by adding cellulose fiber in different percentage in concrete. The compressive strength of M20 and M25 Grade normal concrete with and without cellulose fiber were studied. The test results are very promising. Cellulose fiber are classified as natural fiber, derived from the processing of wood. The processed cellulose fiber have relatively good mechanical properties when compared with many man-made fiber such as polypropylene, polyester, acrylic and so forth Cellulose fiber provide a desirable balance between mechanical, physical, and durability characteristics when placed in cement matrix. Cement composites reinforced by Cellulose fiber are most suitable for foundation floor for machinery in factories, fabrication of light weight cement based roofing and ceiling boards, wall plaster, and construction materials for low-cost housing. A combination of interesting mechanical and physical properties and their environmental benefits has been the main driver for their use as alternatives for conventional reinforcements cellulose fibers exhibit a set of important advantages, such as wide availability at relatively low cost, bio-renewability, ability to be recycled, biodegradability, non-hazardous nature, zero carbon footprint, and interesting physical and mechanical properties.

Deoxygenation of graphene oxide using biocompatible reducing agent Ficus carica (dried ripe fig)

To address the environmental concerns, a relatively simple, innovative and low-cost procedure has been suggested for synthesis of graphene nanosheets (GNSs). The procedure utilized here for synthesizing GNSs is derived from aqueous suspension of graphene oxide (GO). Ficus carica (FC) is known to be remarkable antioxidant. It is regarded as suitable biocompatible alternative to hazardous and toxic chemicals. This method ensures non-hazardous nature of the deoxygenating agent (FC) as well as their oxidized outcomes. Structural and morphological characterization indicates the absence of oxygen-bearing groups from graphene oxide. Characterization was done by standard techniques such as X-ray crystallography, FTIR, RAMAN, DLS, and UV–Vis spectrophotometry. Morphological investigation of resulting material was also undertaken through standard techniques by FESEM, TEM, HRTEM with SAED pattern. Thermal stability of FC derived graphene was also investigated. The investigation may initiate new routes for preparing GNSs at large scale facilitating a better research and commercial utilization.Graphical abstract

Characterisation of jarofix for use in geotechnical projects

A detailed laboratory study was carried out to evaluate the physical, chemical and geotechnical characteristics of jarofix (a waste material generated by the zinc industry) before assessing its applicability for embankment construction. Mineralogical and morphological properties, shape, crystallinity and the concentration of inorganic and heavy metals were evaluated. The stress–displacement behaviour of jarofix was studied by conducting a series of direct shear tests at different normal stresses and dry densities. The parameters studied were the shear stress, shear stress ratio, horizontal and vertical displacements, peak and critical friction angles and dilation. These parameters were compared with those of other suitable embankment materials. It was found that jarofix has a polycrystalline structure with cuboidal particles and a non-hazardous nature. The peak shear stress values at higher density were significantly higher than those at lower density. The stress–strain and volume-change behaviour of the jarofix was found to be similar to those of silty soil, fly ash, sandy soil and dense sand. It is concluded that jarofix can be utilised as an alternative embankment material for sustainable road construction.

Development of an auto-phase separable and reusable graphene oxide-potato starch based cross-linked bio-composite adsorbent for removal of methylene blue dye

In this work, we report the development of a cross-linked bio-composite consisting of graphene oxide, potato starch, cross-linker glutaraldehyde and its application to adsorption of the industrial dye, methylene blue, from aqueous solution. The inexpensiveness, non-hazardous nature and easy bio-degradability are the major reasons for the selection of starch material as one of the components of the bio-composite. The bio-composite has been characterized by FTIR, SEM, XRD, particle size and zeta potential analysis. The FTIR analysis reveals the nature of the binding sites and surface morphology of the bio-composite can be understood through SEM. The auto-phase separability of the adsorbent i.e., the precipitation of the adsorbent without any mechanical means is another factor which makes this particular material very attractive as an adsorbent. Parameters like adsorbent dosage, pH, temperature, rotation speed and salt concentration have been varied to find out the suitable dye adsorption conditions. Furthermore, the time dependence of adsorption process has been analyzed using pseudo-first and pseudo-second order kinetics. The adsorption isotherms have been constructed to suggest convincing mechanistic pathway for this adsorption process. Finally, desorption studies have been successfully performed in 3 cycles, establishing the reusability of the material, which should allow the adsorbent to be economically promising for practical application in wastewater treatment.

Highly selective and safe ‘in vitro’ detection of biologically important ‘Uric acid’ in living cells by a new fluorescent ‘turn-on’ probe along with quantum chemical calculation

A very important human body content and biologically active Uric acid (UA) was specifically and selectively detected by a new fluorescent ‘turn-on’ probe (R1). Sharp and instant colour change from colourless to pink and visually detectable bright red fluorescence made the probe very useful for easy detection of UA. New peak generation at colour region for both UV and fluorescence spectra suggested the strong hydrogen bonding interaction and complex formation between R1 and UA. Very clear ‘off–on’ fluorescence response and the non-hazardous nature of R1 were fruitfully applied for in vitro detection of UA in living HeLa cells. This chemosensor has also been applied to quantify the actual concentration of UA in blood serum collected from clinical laboratory. The probable binding mode and the optimized geometries of the probe and its complex were calculated by quantum chemical (DFT) calculation.

PROPERTIES AND MODIFICATION METHODS OF HALLOYSITE NANOTUBES: A STATE-OF-THE-ART REVIEW

The halloysite nanotubes (HNTs) are naturally found in New Zealand, China, Brazil, America, and France. Halloysite nanotubes have unique physical, chemical, and electrochemical properties. Due to their non-hazardous nature and easy availability, they are used in various fields of science. To improve halloysite nanotubes’ interactions, these can be functionalized by different modification methods like covalent functionalization, non-covalent functionalization, etc. The chemical formula of halloysite nanotubes is Al2Si2O5(OH)4.2H2O. HNTs have a nanotubular geometry which exhibit its dimensions on nanoscale. This nanotubular array of HNTs varies with different regions. In this review, we have tried to reiterate the key properties and various methods to modify halloysite nanotubes.

Effect of addition of 1-butyl-3-methylimidazolium thiocyanate on conductivity of Na-containing polymer electrolyte

Research in the environmentally friendly energy field has grown rapidly due to severe problems such as global warming and climate change. Sodium-ion technology is one of the most promising alternatives to lithium-ion batteries. Use of ionic liquids containing thiocyanate anion has been considered because of their low cost, low viscosity, and nonhazardous nature. In this work, polyethylene oxide (PEO)–sodium perchlorate (NaClO4) samples containing different amounts of 1-butyl-3-methylimidazolium thiocyanate ionic liquid were prepared by a solution casting method. Addition of the ionic liquid to the PEO–NaClO4 electrolyte further increased the ionic conductivity. The electrolyte containing 30 wt% ionic liquid exhibited the maximum ionic conductivity of ~5.0 × 10−4 S/cm at room temperature. Fourier-transform infrared (FT-IR) spectroscopy revealed the interaction between the polymer chain and salt ion complexes for various sodium salt contents. Differential scanning calorimetry (DSC) demonstrated that the crystallinity was reduced by addition of 1-butyl-3-methylimidazolium thiocyanate ionic liquid.

Development of a novel pH sensitive silane crosslinked injectable hydrogel for controlled release of neomycin sulfate

Silane crosslinked biopolymer based novel pH-responsive hydrogels were fabricated by blending the cationic (chitosan) and anionic (alginate) polymers with poly(vinyl alcohol). Tetraethoxysilane (TEOS) was used, as a crosslinker in different amounts due to its nonhazardous nature, to study its impact on physical and chemical properties of the prepared injectable hydrogels along with the controlled release of drug. The swelling response of the prepared hydrogels was examined in different solvent media which exhibited decreased swelling ratio with increase in the amount of TEOS. All the fabricated hydrogels represented highest swelling at acidic pH while low swelling at basic and neutral pH. This specific pH sensitive behavior at pH 7 made them an appropriate candidate for the injectable controlled drug delivery in which Neomycin Sulfate (NMS) was successfully loaded on suitable hydrogel (comprising 50μL TEOS) to study its release mechanism. The results revealed that in simulated gastric fluid (SGF), hydrogel released the entire drug (NMS) in initial 30min while in simulated intestinal fluid (SIF), NMS was released in a controlled way up to 83% in 80min. These results endorsed that the hydrogels could be practiced as a smart intelligent material for injectable controlled drug delivery as well as for other biomedical applications at physiological pH.