Waste Extract Research Articles

Antimicrobial of tropical fruit and vegetable waste extract for food-borne pathogenic bacteria.

Tropical fruit and vegetable wastes become great potential natural resources of bioactive compounds for antimicrobial. The aim of the study was to determine the effect of antimicrobial extracted from tropical fruit and vegetable waste to inhibit foodborne pathogenic bacteria (Aeromonas hydrophilla, Bacillus cereus, Escherichia coli, Listeria monocytogenes, Salmonella Typhimurium, Staphylococcus aureus, Vibrio parahaemolyticus). A total of six tropical fruit waste (peel of pineapple, jackfruit, durian, coffee, mangosteen, and cacao pods) and five tropical vegetable waste (stem of sembukan, lamtoro pods, jengkol shell, bitter bean pods, Indian marsh fleabane leave) was extracted by using maceration method. The antimicrobial activity of extracts was carried out by using disc diffusion assay and Minimum Inhibitory Concentration. The flavonoids in extract were identified and quantified by using Liquid Chromatography-Mass Spectrometry. The highest antimicrobial activity against Gram-positive bacteria (B. cereus, L. monocytogenes and S. aureus) was shown by jengkol, bitter bean and mangosteen waste extract in the range of 0,00038 to 4,2% for MIC. The highest antimicrobial activity inhibits Gram-negative bacteria (A. hydrophilla, E. coli, S. Typhimurium and V. parahaemolyticus) was shown by jengkol, bitter bean, mangosteen, sembukan and lamtoro waste extract in the range of 0,00038 to 3,1% for MIC which have apigenin, catechin, coumaric acid, gallic acid, genistein, hydroxybenzoic acids, luteolin, myricetin, naringenin dan quercetin as bioactive compounds. Total phenol of those waste extracts was in the range of 0.663 to 4,441 mg GAE/g. Jengkol, bitter bean, mangosteen, sembukan and lamtoro waste extract shown to be a potential natural antimicrobial to inhibit food-borne pathogenic bacteria.

Green Extraction of Orange Peel Waste Reduces TNFα-Induced Vascular Inflammation and Endothelial Dysfunction.

Orange peel waste (OPW) is known to contain an abundant amount of polyphenols compounds such as flavonoids, well-reported for their antioxidant and anti-inflammatory properties. While OPW is generally regarded as a food waste, the opportunity to extract bioactive compounds from these “wastes” arises due to their abundance, allowing the investigation of their potential effects on endothelial cells. Hence, this study aims to use a green extraction method and pressurized hot water extraction (PHWE) to extract bioactive compounds from OPW. Liquid chromatography with UV detection (LC/UV) and liquid chromatography mass spectrometry (LC/MS) were subsequently used to identify the bioactive compounds present. Through the optimization of the extraction temperature for PHWE, our results demonstrated that extraction temperatures of 60 °C and 80 °C yield distinct bioactive compounds and resulted in better antioxidant capacity compared to other extraction temperatures or organic solvent extraction. Despite having similar antioxidant capacity, their effects on endothelial cells were distinct. Specifically, treatment of endothelial cells with 60 °C OPW extracts inhibited TNFα-induced vascular inflammation and endothelial dysfunction in vitro, suggesting that OPW possess vasoprotective effects likely mediated by anti-inflammatory effects.

Optimization of mechanical properties and composition of M-sand and pet particle added concrete using hybrid deep neural network-horse herd optimization algorithm

• Natural sand extraction, Granite & Basalt wastes are a problem, hence five Novel concrete design mixes are made. • Concrete performance and Durability tests are conducted and compared with the Predicted results of familiar algorithms. • Results show that the Design Mix P7.5 Containing 7.5% PET particles is the best Mix among all the Mixes made. • While Hybrid DNN-HHO proved to be the best algorithm among the other algorithms used in the investigation. Concrete is one of the broadly utilized materials due to the unavoidable nature of construction. The requirement for improvement in mechanical properties and environmental hazards with the usage of natural sand requires an alternative choice in raw materials. This research work is carried out to investigate the compressive and tensile strength properties of concrete prepared by adding manufactured sand (M-sand) sand and polyethylene terephthalate (PET) particles. Pullout test, Water Absorption (WA), Electrical Resistivity (ER), Rapid Chloride Permeability Test (RCPT), X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) are also analyzed in addition to compressive and tensile strength. A suitable proportion of materials is studied from the preliminary investigation and produced five different concrete specimens for this study. New proportions of concrete mixes with cost-effective materials such as PET and M sand are contributed to enhancing the strength and tensile properties. Cylindrical-shaped concrete specimens are created with final mix proportions and their properties are studied for six different days. The results show that the final specimen has acquired a maximum compressive strength of 45.3 MPa, a maximum tensile strength of 3.77 MPa, a maximum flexural strength of 4.72 MPa, and a minimum water absorption of 8.087 were all obtained by 7.5P specimen after 90 days of synthesis. The X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) analysis results taken for 7.5P specimen after 90 days indicate the presence of PET provide more strength and tensile properties. The properties of the proposed concrete composition is validated and compared with predicted values obtained from Deep Neural Network-Horse herd Optimization Algorithm (DNN-HHO) to find accurate results. The proposed concrete indicates an enhanced result in mechanical properties along with the reduction in environmental issues and can be utilized in the construction field of small applications.

Lactobacillus acidophilus and Lactobacillus cereus-containing products do reduce soybean antinutritional factors

Abstract. Soybean has shown over the years to be a reliable plant protein source to excellently substitute the high cost fishmeal in aquaculture diets. However, antinutritional factors (ANFs) limit its usage in aquaculture feeds. Therefore, the current study was designed to test the efficacy of three substrates containing different microorganisms that are capable of reducing soybean ANFs in a 3-month period at a low pH of 2.8. Full fat soybean (USB) was fermented using Anaerobic waste extract from Recirculating Aquaculture System sludge trap (RASW); Biocentric® Feed probiotic powder (BIOP); Oakland® double cream yoghurt (3x 106 CFU ml¯¹) (OY), Control treatment which had no substrate that contained fermenting microorganism (SRR). Each treatment was conducted in three replicates at 2.8 pH. The untreated soybean granules recorded a numerical protein content of 48.56%. The BIOP fermented soybean recorded significantly higher protein content as compared to the other soybean meal fermented with the other substrates. There was also a significant decrease in the soybean content of the amino acid lysine upon fermentation with the four treatments. Fermentation of the soybean with the four treatments was not significantly different in relation with their soybean lipid content, crude fibre content, methionine + cysteine, dry matter content, urease activity and gross energy content (P > 0.05). There was an overall significant decrease in the ANFs when soybean was fermented with the four treatments, with four out of six analysed ANFs parameters content showing a significant decrease upon fermentation (P < 0.05). Fermentation of the soybean with RASW resulted in a significant decrease of trypsin inhibitor content as compared to the rest of the treatments. The USB recorded a numerical value of 43.80 for trypsin inhibitor, whereas RASW fermented soybean recorded least trypsin inhibitor of 3815 ± 010 mg/g. In conclusion, the current study showed that the fermentation substrates used are capable of reducing soybean ANFs, with a slight decrease in soybean protein content.

Effect of Titanium Dioxide Nanoparticle on Properties of Nanocomposite Membrane Made of Bacterial Cellulose

ABSTRACT The purpose of this study was to see the effect of adding TiO2 nanoparticles had on the characteristics of bacterial nanocellulose (BNC)-based membranes. Pellicles were created from the pineapple peel waste extract, and to obtain BNC, pellicle was disintegrated in six cycles using high-pressure homogenizer at 150 bar. The concentrations of TiO2 nanoparticles in the membrane reinforcement solution were 0.5, 1.0, 1.5, 2.0, and 2.5 wt.%. They were sonicated and dried in an oven at 60°C for 8 h. X-ray diffraction, Fourier transform infrared spectroscopy, roughness test, mechanical properties, and scanning electron microscopy were investigated to explore its claims. The results revealed that diffraction pattern of BNC/TiO2 membrane has a new peak at 25.05° that ensures the presence of TiO2 nanoparticles as well as diffraction peak occurred at 22.49°, which indicates the presence of cellulose Iβ. Moreover, the addition of TiO2 nanoparticles until 1.5 wt.%, the crystallinity index is relatively same and the optimum strength of 99.5 MPa was attained. Further, improvement in addition of TiO2 nanoparticle at 2 wt.% showed a decline in crystallinity index as 80.16% to 74.72% at 2.5 wt.%. The morphology of the membrane surface revealed that TiO2 nanoparticles were still agglomerated and not equally distributed across the BNC membrane, leading to increase in surface roughness.

Numerical Study on V Shaped Natural Draft Cooling Tower Supporting System

Cooling towers generally used to extract waste heat to the atmosphere from cooling water stream to a lower temperature and hence it rejects heat from water. The size of the cooling tower is large, with thin wall and complex geometry. Wind load plays a dominant role in the design of cooling tower. These cooling towers are subjected to self-weight and dynamic loads such as wind and earthquake. This paper presents the study of cooling tower of height 200m above the ground level. The Analysis of a cooling tower is done for a wind load using a finite element analysis considering V frame shell base supporting system. The analysis is performed in Commercial software STAAD PRO and the results obtained are presented in this paper.

Water-based drill cuttings, a shale gas extraction waste as supplementary cementitious material and optimization

• A method of preparing a novel supplementary cementitious material based on water-based drill cuttings was provided. • A central composite design was conducted to optimize the four factors (calcination temperature, calcination time, replacement ratio, and fineness) for WDC preparation, and optimal values were obtained. • The hardened specimens, prepared with a mixture of standard sand, ordinary Portland cement, and water-based drill cuttings, meet the compressive strength specified in ASTM-618. • The mechanisms of WDC acting in the OPC system were investigated. The water-based drill cuttings, a kind of solid waste from shale gas extraction, are examined for their utility as supplementary cementitious material. After drying, calcining, and grinding, water-based drill cuttings are expected to partially replace ordinary Portland cement for their high calcium silicate and grinding-friendly nature. A central composite design investigated four variables (calcination time, calcination temperature, replacement ratio, and fineness) for their effects on the response (compressive strength). The optimization results suggest that the best product meeting the mechanical criteria and saving energy could be obtained by replacing 10 wt% ordinary Portland cement when controlling the calcination temperature of 830–870 °C, calcination time of 28–32 min, and fineness of sieving is 1600 mesh. The compressive strength was shown to be 39.00 MPa at 7 days, 47.00 MPa at 28 days, and 52.00 MPa at 90 days. Furthermore, the mechanisms of water-based drill cuttings were characterized to confirm the feasibility of supplementary cementitious material by various analytical techniques such as X-ray fluorescence, laser particle size analyzer, simultaneous thermogravimetric analysis, X-ray diffraction, and scanning electron microscopy.

Ameliorating Direct Blue Dye Degradation Using Trametes versicolor Derived Laccase Enzyme Optimized through Box–Behnken Design (BBD) via Submerged Fermentation

The major intend of this study was to elucidate the laccase production by Trametes versicolor under submerged fermentation using fruit waste peel as substrate. The textile dye was decolorized by the procured crude enzymatic extract using the response surface methodology. The submerged media with organic fruit peel waste extract (jackfruit, pineapple & kaffir) supplemented with gypsum, calcium carbonate, and nutrient broth were considered superior for laccase production. The produced laccase enzyme was used in dye decolorization at the optimum conditions using the Box-Behnken design. Subsequently, the experiment was designed with four variables (dye concentration, pH, temperature & time) with three factors to achieve the maximum direct blue dye decolorization. The highest laccase activity level was obtained from jackfruit peel extract with 3.86U/ml on 15th day at 25oC with pH 5.0 when compared to the other two extracts. The maximum laccase activity with guaiacol was obtained at optimum pH 4 and 40oC. The predicted value was experimentally validated by attaining 81.25% of dye color removal. From the result, the optimum conditions for direct blue color removal were: dye concentration 40ppm, pH 4.0, temperature 40oC at 24 hours. From the results of this study, it was concluded that the jack fruit peel was a more suitable substrate for laccase production. The dye decolorization results were recommended that Box-Behnken design for parameters optimization. The T. versicolor laccase was more proficient for textile dye decolorization. The opportunity was created by using the laccase enzyme for the biological treatment of textile dyeing effluent before discharging into the environment.

Characterization of carotenoids double-encapsulated and incorporate in functional stirred yogurt

Carrot industry processing outputs 50% waste from raw materials; this waste contains polyphenols and carotenoids, which are a significant natural source of pro-vitamin A. Also, yogurt's high consumption globally allows for designing a new functional product. So the goal is to enhance the functionality of fortified stirred yogurt by incorporating carotenoid beads. The carotenoids were extracted from carrot waste using ultrasonication. Then nanoemulsion carotenoids incorporating with alginate to produce beads by extrusion technique. Measurement of carotenoid stability to nanoemulsion and beads. Manufactured five treatments of orange-flavored stirred yogurt and investigated its physicochemical properties, LAB survival, viscosity, and sensory acceptability. Findings – Carrot waste extract had about 44.75 ± 3.15 mg/g of β-carotene. The mean particle size of the nanoemulsion decreased with the increasing carotenoid addition (0.5%, 1%, and 1.5%) of carrot waste extract. The mean diameters of the alginate beads with nanoemulsions were 1.498 ± 0.245, 1.654 ± 0.310, and 1.792 ± 0.454 mm, respectively. The highest chemical stability of carotenoids showed with the alginate beads after Storage at 55°C to 14 days, compared with free or nanoemulsion carotenoids. Yogurt's physicochemical properties, viscosity, and LAB count improve when double-encapsulated carotenoids are added. Carotenoid double-encapsulation appeared to have a high ability to protect carotenoids from degradation and the ability to be applied in dairy and pharmaceutical products. Also, the resultant stirred yogurt with carotenoids-loaded beads gave carotenoids high stability and sensory acceptability.

Green synthesis of nanoparticles from biodegradable waste extracts and their applications: a critical review

The contemporary world is concerned only with non-biodegradable waste management which needs more sophisticated procedures as compared to biodegradable waste management. Biodegradable waste has the potential to become useful to society through a simple volarization technique. The researchers are behind sustainable nanotechnology pathways which are made possible by using biodegradable waste for the preparation of nanomaterials. This review emphasizes the potentialities of biodegradable waste produced as a viable alternative to create a sustainable economy that benefits all humans. Volarization results in the utilization of biowastes as well as provides safer and hazard-free green methods for the synthesis of nanoparticles. Starting from different sources to the application which includes therapeutics, food industry and water treatment. The review hovers over the pros and cons of biowaste-mediated nanoparticles and concludes with possible advances in the application. In the present scenario, the combination of green synthesis and biowaste can bring about a wide variety of applications in nanotechnology once the hurdles of bulk-scale industrial production are resolved. Given these points, the review is focused on the cost-effective synthesis of metal and metal oxide nanoparticles.

Waste Utilization: Physicochemical characteristics, stability and applications of emulsified Rana chensinensis ovum oil with waste extracts.

Rana chensinensis ovum (RCO) is the major waste/by-product of Oviductus Ranae. This study investigated physicochemical characteristics and stability of emulsified Rana chensinensis ovum oil (RCOO) with Rana chensinensis ovum protein isolates (RCOPI) by particle size, zeta potential, scanning electron microscopy (SEM), visual appearance, confocal laser scanning microscopy (CLSM), rheology and antioxidant capacity. The emulsified RCOO demonstrated great stability, antioxidant capacity and rheological properties. The potential application of the emulsified RCOO as a delivery system was studied using quercetin as an example. The stability of encapsulated quercetin was investigated through storage stability, thermal stability and photostability. The bioaccessibility of encapsulated quercetin was explored by in vitro digestion simulation experiments. The results showed the stability and bioaccessibility of quercetin encapsulated in emulsified RCOO was greatly improved. This study showed that the emulsified RCOO is a promising edible delivery system for hydrophobic bio-actives.

Effects of Pleurotus pulmonarius stalk waste extract‐supplemented feed on the immune responses of red hybrid tilapia Oreochromis sp. following challenge with pathogen‐associated molecular patterns

Intensive farming of red hybrid tilapia Oreochromis sp. significantly increases the emergence of infectious diseases. Recently, dietary administration of functional feed additives is gaining popularity as an alternative to antibiotics and chemotherapeutics. Mushroom stalk waste (MSW), which possesses the same therapeutic effects as the fruiting body, has immense potential as a cost-effective feed additive in aquaculture. In the present study, 10 g/kg of the ethanol-pretreated hot water extract (E-HWE) of Pleurotus pulmonarius stalk waste was supplemented in the feed of red hybrid tilapia for a 30-day period to determine the effects on growth performance and immune activation after challenging the fish with pathogen-associated molecular patterns (PAMPs). Results showed that E-HWE supplementation significantly improved (p < 0.05) the feed conversion ratio, protein efficiency ratio and hepatosomatic index in red hybrid tilapia but had no apparent effect on the growth. Upon PAMPs challenge, the phagocytic activity and respiratory burst activity of blood leukocytes were significantly enhanced (p < 0.05) in E-HWE-supplemented group. E-HWE supplementation also resulted in significantly higher (p < 0.05) serum haemolytic activity and bactericidal activity. All immune-related genes investigated were upregulated in E-HWE-supplemented group; il1b, tnfa and tlr3 revealed higher expression levels at day 1 post-PAMPs challenge, while ighm and tcrb genes expression levels were elevated after 3 days PAMPs challenge. This study revealed that E-HWE could be a promising and cost-effective feed additive in red hybrid tilapia farming which may also provide a solution for MSW disposal.

Valorization of Berries' Agro-Industrial Waste in the Development of Biodegradable Pectin-Based Films for Fresh Salmon (Salmo salar) Shelf-Life Monitoring.

The healthy properties of berries are known; however, red fruits are very perishable, generating large losses in production and marketing. Nonetheless, these wastes can be revalued and used. The main objective of this study was the development of biodegradable pectin films with berry agro-industrial waste extracts to monitor salmon shelf-life. The obtained extracts from blueberries, blackberries, and raspberries wastes were evaluated in terms of flavonols, phenols and anthocyanins contents, and antioxidant capacity. Then, pectin films with the extracts of different berries were developed and characterized. The results showed that the blueberry extract film was thicker (0.248 mm), darker (L* = 61.42), and opaquer (17.71%), while the highest density (1.477 g/cm3) was shown by the raspberry films. The results also showed that blueberries were the best for further application due to their composition in bioactive compounds, antioxidant capacity, and color change at different pHs. The salmon samples wrapped in blueberry films showed lower values of pH and deterioration of fish during storage compared to the control and pectin samples. This study contributes to the valorization of berries agro-industrial waste by the development of eco-friendly films that can be used in the future as intelligent food packaging materials contributing to the extension of food shelf-life as a sustainable packaging alternative.

Wine residues extracts modulating in vitro metabolic syndrome

Metabolic syndrome is considered a worldwide epidemic health problem. The manifestations include obesity, dyslipidemias, elevation of arterial blood pressure, and insulin resistance. The wine waste is composed mainly of skin, seed and grape pomace, and is a source of phenolic compounds. Previous studies have demonstrated that grape phenolic compounds have antioxidants and anti-inflammatory properties, acting directly in the pathogenic process of several diseases. In order to improve the bioavailability and bioactivity of these compounds, enzymatic biotransformation reactions were developed.The aimed of this work was to evaluate whether phenolic extracts produced with wine waste by biotransformation with Tannase (tannin acyl hydrolase), were able to attenuate the metabolic syndrome manifestations like oxidative stress and reduce the inflammatory parameters in vitro assays.Four different extracts were produced and the non-citotoxic concentrations of samples used (100, 200 and 500 μg/mL) were determined by MTT assay. The inflammatory response was induced in macrophages (RAW 264.7) culture using LPS (Lipopolysaccharide). The biotransformed extracts were able to reduce the TNF-α cell culture supernatant concentration by about 44%; and the IL-6 secretion was reduced by 82%. All the extracts demonstrate efficacy in reduction of intracellular reactive oxygen species (ROS) production and the same was observed for NO (nitric oxide) concentration in the cell culture supernatant after the administration of extracts. These results indicated the strong potential of employing phenolic wine waste extracts on the modulation of metabolic syndrome parameters, use that also brings environmental and socioeconomic advantages, since it brings an alternative for the use of residues.

Structural study and metal speciation assessments of waste PCBs and environmental implications: Outlooks for choosing efficient recycling routes

Environmental protection from risks and disposal management of discarded mobile phone printed circuit boards (MPhPCBs) is a global issue. Although recycling is proposed as a solution, it is challenging to choose a sustainable method due to the insufficient recognition from extreme structural heterogeneity of these wastes based on their types. To this end, a thorough study on the structural characterization of PCBs using different analyses and metal speciation by sequential extraction procedure were performed. Understanding these information is an essential step in order to choose efficient methods to maximize selective recycling of metals and minimize environmental implications. PCBs were found to be potent metallic reservoirs after all metal content of PCBs were precisely measured. The structural analysis results of the sample included identification of different phases, functional groups, 45.1 % of the crystalline and 54.9 % of amorphous, the mesoporous nature (pore diameter mean ∼ 7.24 nm), hydrophobic property (contact angle ∼93.4°), the positive ζ-potential of particles at pH < (isoelectric point ∼5.4) and vice versa, and the particle size that were not oversized. The metal speciation outcome indicated over 80 % of the total content of elements such as Si, Sn, Ag, Au, Sr, Al, Cr, Nd, Ca, Ba, and P was in a solid crystal structure/residual fraction, which were hard recycled. The assessment of contamination levels of waste indicated the considerable contamination for the environment at global contamination factor ∼27.7, the moderate ecological risk at potential ecological risk assessment ∼82.9, and threats to public health. In addition, the metals of Pr, Mn, and Zn pose high risks because of their risk assessment code values of 42.7 %, 36.7 %, and 33.1 %, respectively. Leaching tests proved Waste Extraction Test was an aggressive method. ANC4 proposed high level of H+ consumption are required for metal leaching in future works.

Time-Series Monitoring of Dust-Proof Nets Covering Urban Construction Waste by Multispectral Images in Zhengzhou, China

Rapid urbanization has produced a huge amount of construction waste. The operations and consequences of construction and demolition can lead to windblown dust problems, profoundly affecting the living environment of residents. Fortunately, dust-proof nets have been used in construction sites to reduce and prevent pollution by fine particles such as dust, so it is important to monitor and evaluate their efficacy. In this study, Earth observation techniques were used for the extraction and monitoring of solid waste and dust-proof nets. In order to fully perceive the validity and necessity of dust-proof nets for urban air health, we conducted a case study in Zhengzhou, China. We explored the potential of multispectral remote sensing available for monitoring urban construction waste and proposed a multi-layer classification method to identify construction waste and dust-proof nets based on Landsat-8 OLI and Sentinel-2 MSI data, with an average identification accuracy and Kappa coefficient of 96.27% and 0.93 for construction waste in the study area from 2015 to 2020, respectively. In addition, our study revealed the driving factors and impact of temporal variations in regional construction waste areas and dust-proof nets coverage. The results indicate the classification can track municipal solid waste management and changes in air pollutant concentrations and is useful for achieving SDG 11.6 (reduce the adverse per capita environmental impact of cities, including by paying special attention to air quality and municipal and other waste management). This study has the potential to monitor construction waste and dust-proof nets, paving the way for better urban environmental governance and surveillance actions in the future, especially involving big data.

ENVIRONMENTAL MONITORING MANAGEMENT OF WASTE FROM LARGE EXCAVATIONS DUE TO INFRASTRUCTURE BUILDINGS

Abstract. Large infrastructure building like the Florence Railway Station designed for high-speed rails requires a proper management of the huge quantity of waste originating from excavation activities. Such waste amounts require large areas for disposals, making abandoned areas or exhausted quarries and mines ideal sites for hosting the excavated wastes.A rectangular area of 500×70m delimiting the railway station has been excavated in two steps causing the removal of a 10m-thick soil layer per step: excavated earth and rocks would then be used for the environmental restoration of an area of 400×350m located near a former exhausted lignite quarry) in the proximity of the Santa Barbara village near Cavriglia (Arezzo).The Tuscan Regional Environmental Agency (ARPAT) have been involved in monitoring both the terrain transportation and disposals’ operations according to the approved management plan: the Environmental Regional Information System Office (SIRA) was asked to evaluate volume balancing between all the waste management cycle, with included: (a) waste extraction from railway station site building, and (b) waste disposal final destination (exhausted Santa Barbara lignite quarry).Terrestrial Laser Scanner (TLS), Simultaneous Localization and Mapping System (SLAM) systems and Remotely Piloted Aircraft Systems (RPAS) surveys have been used to track earth and rocks excavation and disposal activities in the aforementioned sites: while RPAS systems cannot be used in underground site surveys, their usage must be recommended in open space surveys due to the ese of use if sub-centimetric precisions are not required.Multiple TLS scans alignment can result in a quite challenging task if automatic alignment software is not available, requiring manual rough alignment’s operations that can be very time consuming: two open-source solutions based on different algorithms have been evaluated.The selected survey technologies – RPAS, TLS, SLAM – have shown a great potential in earth and rocks monitoring: each technology has its own strengths and weakness, which can vary on the basis of both hardware and software technical progresses.

A review of EN 16907 on earthworks (extractive waste) in the context of South African mine residues

Rather quietly, a new generation of European norms dealing with earthworks has been developed over the past few years, in particular a part of EN 16907 pertaining to extractive waste. Whereas the majority of the parts deal with routine geotechnical aspects, one part deals specifically with tailings dams. The standard is currently in draft form but if this becomes a European Standard, members of the European Union are bound to comply with the regulations. As such, the standard has the capacity to influence mining in Europe and potentially in South Africa. In this paper we review the standard and compare it to the South African standard on mine residues and the recently published Global Industry Standard on Tailings Management (GISTM). We conclude found that although the European norm makes great strides towards increasing tailings dam safety, there is room for improvement. The current South African standard has served well since its inception, but can be improved by using concepts from the European and global tailings standards.

Unveiling Antimicrobial and Insecticidal Activities of Biosynthesized Selenium Nanoparticles Using Prickly Pear Peel Waste

In the current study, prickly pear peel waste (PPPW) extract was used for the biosynthesis of selenium nanoparticles through a green and eco-friendly method for the first time. The biosynthesized SeNPs were characterized using UV-Vis, XRD, FTIR, TEM, SEM, EDX, and mapping. Characterization results revealed that biosynthesized SeNPs were spherical, polydisperse, highly crystalline, and had sizes in the range of 10–87.4 nm. Antibacterial, antifungal, and insecticidal activities of biosynthesized SeNPs were evaluated. Results revealed that SeNPs exhibited promising antibacterial against Gram negative (E. coli and P. aeruginosa) and Gram positive (B. subtilis and S. aureus) bacteria where MICs were 125, 125, 62.5, and 15.62 µg/mL, respectively. Moreover, SeNPs showed potential antifungal activity toward Candida albicans and Cryptococcus neoformans where MICs were 3.9 and 7.81 µg/mL, respectively. Furthermore, tested crud extract and SeNPs severely induced larvicidal activity for tested mosquitoes with LC50 and LC90 of 219.841, 950.087 mg/L and 75.411, 208.289 mg/L, respectively. The fecundity and hatchability of C. pipiens mosquito were significantly decreased as applied concentrations increased either for the crude or the fabricated SeNPs extracts. In conclusion, the biosynthesized SeNPs using prickly pear peel waste have antibacterial, antifungal, and insecticidal activities, which can be used in biomedical and environmental applications.

An improved surface enhanced Raman spectroscopic method using a paper-based grape skin-gold nanoparticles/graphene oxide substrate for detection of rhodamine 6G in water and food.

Organic toxins are persistent chemicals of global concern capable of accumulating in environment and food. Surface enhanced Raman spectroscopy (SERS) is a promising technique that facilitates onsite detection of organic toxins. However, the fabrication of a SERS substrate is complicated and difficult to provide flexibility, fastness and cost-effectiveness. This study aims to develop a paper-based SERS method using grape skin-gold nanoparticles/graphene oxide (GE-AuNPs/GO) as SERS substrate and evaluate its efficiency with rhodamine 6G (Rh6G) as a model organic toxin and a real water and food contaminant. GE-AuNPs synthesized by green method using grape skin waste extract and GE-AuNPs/GO showed a surface plasmon resonance at 536 and 539nm, particle size 18.6 and 19.5nm, and zeta potential -44.6 and -59.7mV, respectively. Paper-based SERS substrates were prepared by coating a hydrophobic thin-film of 30% polydimethylsiloxane solution in hexane on Whatman no. 1 filter paper, followed by drop-casting GE-AuNPs or GE-AuNPs/GO and drying. The SERS signals of Rh6G showed an enhancement factor of 5.8×104 for GE-AuNPs and 1.92×109 for GE-AuNPs/GO, implying that a combination of electromagnetic surface plasmon, charge transfer and molecular resonances may be responsible for a higher enhancement of signal by the latter. A low detection limit of 7.33×10-11M in the linear range of 10-11-10-5M was obtained for GE-AuNPs/GO, while the relative standard deviation of repeatability and reproducibility was 9.6 and 12.6%, respectively. Paper-based GE-AuNPs/GO SERS substrate was highly stable as <20% loss in efficiency was shown over a 60-day storage period. Application to real samples showed a high recovery of Rh6G from tap water (93.9-100.8%) as well as food samples such as red chilli powder (91.0-95.4%), red glutinous rice ball (96.6-98.3%) and tomato ketchup (98.9-102.3%) after QuEChERS extraction. Collectively, the developed paper-based GE-AuNPs/GO can be a potential substrate for sensitive onsite detection of rhodamine 6G by SERS method.