Waste Ground Research Articles

Impact of solid waste pollution on the phytodiversity of the minor bed of the M’filou River in Brazzaville, Republic of Congo

ABSTRACT The impact of solid pollution on phytodiversity was studied in the minor bed of the M’filou River in Brazzaville, Congo. Anthropogenic disturbances strongly influence the biodiversity of ecosystems, but they can adapt to these changes. The floristic assessment was based on three surveys of 80 m2 each. The basic data were collected using the phytosociological method, supplemented by an itinerant inventory. Solid waste was quantified in the plots. The most represented species are Commelina cf. latifolia, Echinochloa pyramidalis, and Eleusine indica. The flora is characterised by pantropical taxa and therophytes, indicating the adaptive and azonal nature of the vegetation. The prevalence of nitrophytes suggests a high level of nitrates, of which there are various origins. The flora and waste are not highly diverse, are relatively homogeneous, and vary from site to site. The correlation between flora and waste is weak for most taxa, except for plastics. The use of the M’filou urban river as a dumping ground for household and market garden waste has led to significant changes in the flora, depending on the type of pollutants generated.

Effect of fly ash and ground waste glass as cement replacement in concrete 3D-Printing for sustainable construction

Effect of fly ash and ground waste glass as cement replacement in concrete 3D-Printing for sustainable construction

Structural and optical properties of mesoporous akermanite derived from industrial waste for multifunctional applications

The present study focuses on the synthesis of akermanite by chemical free hydrothermal route using two major industrial waste ground granulated blast furnace slag (GGBS) and coal fly ash (FA) as the initial precursors. Further, leaf extract and Cetyltrimethyl ammonium bromide (CTAB) have been used as stabilizing and chelating agent to observe their effect on the structural, optical and morphological properties of the nanoparticles. The synthesized powders were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), ultraviolet visible (UV–visible) spectroscopy, Brunauer-Emmett-Teller (BET) analyser techniques. The detailed structural studies implied that the fabricated powders are akermanite and the average crystallite size was calculated to be in the range 23–27 nm. Field emission scanning electron microscopy analysis showed that the samples synthesized using water and leaf extract adopt rod like morphology while the sample fabricated using CTAB are seed shaped. The calculated bandgap of the developed powders from the UV-Visible reflectance spectra using Kubelka-Munk method lie in the range 3.1–3.26 eV. BET analysis revealed all the samples are mesoporous in nature and their specific surface area were estimated.

Synergistic effect of nano-to-macro waste glass of various particle sizes on ultra-high-performance concrete: Tradeoff between mix design parameters and performance through a statistical design approach

Ultra-high-performance glass concrete (UHPGC) is engineered for strength, ductility, and durability, aiming to address environmental and economic concerns associated with traditional ultra-high-performance concrete (UHPC). In this approach, we individually substituted traditional UHPC components—cement (C), silica fume (SF), quartz sand (QS), and quartz powder (QP) with ground waste glass materials (GWG). Recognizing that the performance of UHPC is influenced by the chemical interactions and packing density of its constituents, which primarily depend on particle-size distribution, our current study focuses on the synergistic effects of these factors. We explored how nano to macro size GWG can simultaneously replace all traditional UHPC components and affect its properties. Employing the Design of Experiment allowed the establishment of statistical equations. Contour diagrams predicted the individual and synergetic effect of mix design parameters on UHPGC's fresh and mechanical properties, with a high correlation (R2 ≥ 0.98) and low error (≤8 %). Validation with 18 additional mixtures confirmed the models' precision. Our research established the production of a superior UHPGC with 40%–100 % lower traditional components (C, SF, QP, and QS) and 65 % less superplasticizer demand. The embodied energy, CO2 emissions, and production cost reduced by 65 %, 38 %, 36 %, and 32 %, respectively. This approach can enhance UHPGC's integrity and environmental sustainability.

تحضير وتقييم بوليمرات رخيصة كمضادات للبكتريا ،الاكسدة ومثبطات تاكل لسبيكة من نوع N80 في تركيز 0.1N من حامض الفسفوريك

في هذا العمل ، تم تحضير بولي بوتادين (PBD) من نفايات الاطارات . وطعم البولي بوتادين المهلجن باستخدام أحادي وثنائي وثلاثي إيثانول امين ، ودرس التطعيم عن طريق حيود الأشعة السينية والمسح المجهري الإلكتروني. وتشير الخواص الحرارية (TGA, DSC) إلى أن المركبات المحضرة تمتلك ثابتًا حرارياً حتى 202 درجة مئوية. باستخدام تقنيات الاستقطاب الديناميكي الفعال ، تم قياس تأثيرات الامتزاز والتآكل للبوليمرات الثلاثة المطعمة على فولاذ N80 في.0.1N H3PO4 في اربع درجات حرارية مختلفة : 25 و 35 و 45 و 55 درجة مئوية. وقد اظهرت البوليمرات المحضرة كفاءة تثبيط ممتازة عند درجات الحرارة المختلفة. يعتبر pBut-g-mono ethanol amine هو الأكثر فعالية كمثبط للتآكل في جميع درجات الحرارة المختبرة. كما ان سلوك الامتزاز للبوليمرات الثلاث تخضع لمخطط لانجموير ، وقيم الطاقة الحرة المتحصلة توضح ان الامتزاز الذي يحدث على سطح N80هو من النوع المختلط كما تشير منحنيات تافل إلى أن البوليمرات المختبرة تعمل كمثبطات أنوديك وكاثودية مختلطة. من ناحية أخرى ،وجد أن جميع البوليمرات المحورة أظهرت خصائص متميزة كمضادة للأكسدة وللبكتيريا.

Fabrication of biopolyethylene-based biocomposites with coffee ground waste: Effect of polyethylene-graft-maleic anhydride

The production of plastic products from non-renewable raw materials, such as petroleum, damages the environment. Consequently, biocomposites have aroused interest from industry and researchers due to their ecologically correct characteristics, mainly because they come from renewable sources. Therefore, this study aimed to produce biopolyethylene/coffee ground waste (BioPE/CGW) biocomposites and analyze the impact of CGW and polyethylene-graft-maleic anhydride (PE-g-MA) on BioPE. The biocomposites were prepared in a co-rotational twin-screw extruder equipped with a side feeder to feed the CGW. The materials were subsequently injection molded to produce the impact, tensile, and HDT samples. The temperature profiles used during extrusion and injection were between 170 and 180°C. The BioPE and biocomposites were investigated for the vibrational (Infrared Spectroscopy - FTIR), thermal (differential scanning calorimetry), mechanical (tensile, impact, and hardness), thermomechanical (heat deflection temperature (HDT) and Vicat softening temperature (VST)), and morphological (scanning electron microscopy (SEM)) properties. The compatibilizer improved the interface between phases, promoting mechanical and thermomechanical improvements in the biocomposites. PE-g-MA promoted increments in tensile strength and elastic modulus of up to 38% and 25% in the BioPE/CGW30 and an increase of 44% in the elastic modulus compared to BioPE. The thermomechanical investigations showed that HDT increased by 8.8 and 3.3°C and VST increased by 2.5 and 6.6°C compared to BioPE and the BioPE/CGW30, respectively. Biocomposites from renewable and biodegradable sources align with a sustainable development concept.

Strength, infiltration characteristics and slope stability of waste ground

Strength, infiltration characteristics and slope stability of waste ground

Feasibility study of biodegradable coffee ground waste and watermelon rind as water-based drilling fluid additives

Addressing environmental concerns in extracting and producing hydrocarbon resources requires environmentally friendly water-based drilling fluid (WBDF) additives. These additives not only protect the environment but also offer operational benefits. One of the major challenges of WBDF is fluid loss into the formation and its degradability in high-temperature conditions, which induce cost, formation alteration and environmental pollution. This study explored the feasibility of wasted watermelon rind powder (WRP) and coffee ground waste powder (CGWP) as potential WBDF additives to regulate fluid loss and modify other rheological properties. WRP and CGWP were characterized using Energy Dispersive X-Ray (EDX) and Fourier Transform Infrared Spectroscopy (FTIR) tests. The thermal stability of the proposed additives was confirmed using a thermogravimetric analysis (TGA) test. Several experiments were conducted to investigate the impact of WRP and CGWP with different weight concentrations (wt.%) on the rheological and drilling fluid properties of conventional WBDF. The results show that at 3 wt%, the WRP improved the plastic viscosity by 75% and the CGWP increased the plastic viscosity by 100%. At the same time, the CGWP reduced the gel strength substantially, while WRP increased the gel strength. At an optimum 3 wt%, the CGWP reduced fluid loss by 53%, resulting in the thinnest filter cake thickness. These results demonstrate the potential use of the studied materials as multifunctional additives in drilling operations with WBDF.

Effects of recycled carbon fibers on mechanical and piezoresistive properties and environmental impact in alkali-activated cementitious materials

The development of alkali-activated cementitious materials (AAM) reinforced with recycled carbon fiber (rCF) is of remarkable significance due to its cost-effectiveness compared to virgin carbon fiber, along with the sustainable reuse of solid waste serving as AAM. This study explores the integration of rCF and solid waste Ground Granulated Blast Furnace Slag (GGBS), aiming for cleaner construction practices. A novel approach involving a high-viscosity one-part GGBS slurry ensured homogeneous rCF dispersion, resulting in alkali-activated slag (AAS) mortars with outstanding overall performance at minimal dosage. At a minimum dosage of 0.1 vol%, rCF significantly enhanced flexural strength by 53.42% and reduced drying shrinkage by over 20%. The uniformly dispersed rCF acts as nucleation sites, boosting early compressive strength without compromising long-term performance. Furthermore, the connected rCF network established an exceptionally low percolation threshold (0.125 vol%) and demonstrated promising piezoelectric properties under cyclic loading, illustrating its potential as self-sensing concrete elements. Additionally, life cycle analysis (LCA) underscored the environmental benefits of rCF and GGBS, revealing their potential to remarkably cut carbon emissions (75.36%) and reduce costs (36.5%). These findings provide valuable insights into the development of rCF-reinforced self-sensing mortar with superior mechanical properties, showcasing the substantial potential of rCF in driving the construction industry toward carbon neutrality.

Magnetic composite – Based dual nanozymes derived from coffee ground waste: A sustainable approach for colorimetric assay and prolonged reuse

Nanozymes serve as an excellent substitute for traditional enzymes across various scientific domains, particularly in the colorimetric sensor array. Nonetheless, their tendency to aggregate into larger clusters and the challenges associated with recovery and reuse have limited their applicability, especially in the context of sustainable development. Based on the 3R principle “Reduce-Recycle-Reuse”, this study introduces a magnetic composite in which two typical nanozymes composed of silver nanoparticles and magnetite nanoparticles are immobilized on the activated carbon derived from spent coffee grounds using one-pot in-situ synthetic approach for easy recovery and long-term reuse. The successful synthesis of the targeted composite was verified through its characterization analysis techniques, including XRD, FT-IR, SEM-EDS, element mapping, HR-TEM, VMS, BET, and TGA. The experimental results revealed that the coexistence of these nanoparticles not only guarantees the magnetic property of the composite but also enhances its peroxide-mimicking activity in the catalytic oxidation of a reliable colorimetric substrate (3,3,5,5-tetramethylbenzidine) through the predominant of •OH radical. The conditions for optimizing the catalytic efficiency of the composite were also presented. Under this condition, the targeted composite showed high accuracy, selectivity, and anti-interference ability in colorimetrically quantifying the ascorbic acid concentration, as confirmed by high-performance liquid chromatography measurement. Notably, the catalytic activity, magnetic property, and fundamental characteristics of the proposed composite remained almost unchanged even after a series of at least 6 consecutive assays. This observation substantiates its remarkable capacity for prolonged reuse, a unique attribute not present in recently developed nanozymes.

The Influence of Excitation Method on the Strength of Glass Powder High-Strength Cementitious Materials

Recycling economy and the re-utilization of solid waste have become important parts of sustainable development strategy. To improve the utilization rate of waste glass, glass powder high-strength cementitious material (GHSC) was prepared by replacing part of the cement in the cementitious material with ground waste glass powder. Firstly, the effect of glass powder particle size on the flexural and compressive strength of GHSC was investigated by the gray correlation method, and the optimal grinding time was obtained. Additionally, the effect of the magnitude of steam curing temperature and the length of steam curing time on the compressive strength and flexural strength of GHSC was investigated, and the mechanism of the effect of the curing regime on the strength was explored by examination of the microstructure. Finally, to simplify the curing process of GHSC, the effects of Ca(OH)2 and Na2SO4 as excitation agents on the compressive strength and flexural strength of GHSC at different dosing levels were compared. The results showed that glass powder with a particle size of less than 20 μm would improve the compressive strength and flexural strength of the specimen. Steam curing can significantly improve the flexural strength and compressive strength of GHSC specimens. At a steam curing temperature of 90 °C for a duration of three days, the compressive strength and flexural strength of GHSC increased by 76.7% and 98.2%, respectively, compared with the standard curing specimens. Ca(OH)2 and Na2SO4 as excitation agents significantly enhanced the compressive and flexural strengths of GHSC under standard curing conditions.

Characterization of different types of silica-based materials

Waste glasses based on silicon dioxide (silica) belong to one of the most demanded secondary raw materials. Besides the glass industry, with strict requirements for source materials, silica-based granular materials from waste glasses are considered suitable for use as fillers in alkali-activated cement-based composites. However, due to variations of ground waste glass powder composition and properties a comprehensive characterization is often needed. This study investigated commercially available silica-based powders by scanning electron microscopy, X-ray photoelectron spectroscopy, attenuated total reflectance Fourier transform infrared spectroscopy and Fourier transform infrared Raman spectroscopy, zeta-potential and pH measurements, etc. The differences found in the non-silica impurities composition and structure of SiO2 particles (amorphous vs crystalline) were considered as determinative factors that will affect particles’ interaction with water and cement binder. The observed results provide a fundamental background and will contribute to a better understanding and explanation of the silica-based secondary raw materials interaction reactions in concrete or mortar.

The Influence of Waste Perlite Powder on Selected Mechanical Properties of Polymer–Cement Composites

The subject of this paper is the influence of the partial substitution of cement with mineral additive on the properties of polymer–cement composites (PCCs). Although there is considerable research on the use of perlite in cement concrete, most of the previous studies were conducted with expanded perlite or ground waste perlite, and there is a lack of results evaluating its suitability with polymer–cement composites. To fill this gap, this paper presents the mechanical characteristic of PCC mortars containing waste perlite powder. The modification consisted of replacing part of the cement with waste perlite powder, a byproduct formed during the expansion and fractionation of perlite. The granulometric characteristics of the powder were compiled, and its specific surface area and density were determined. A chemical composition analysis was also carried out. An aqueous dispersion of styrene–acrylic copolymer was used as a polymer modifier. The proportions (by mass) between the contents of the PCC composite components, i.e., cement/polymer (0 to 20%) and cement/mineral powder (0 to 15%), were used as material variables. The technical characteristics tested included the compressive, flexural, and tensile strengths at 28 and 90 days of curing. The compositions of the tested composites were determined using the statistical planning of the experiment. At a low polymer-modifier content in PCC mortars (2.93%), the tested mechanical strengths decreased by five times, with a 6-fold increase in waste content. For mortars containing more than 10% of the polymer modifier, no effect of waste material powder on the flexural strength was observed, while with relatively minor reductions in compressive strength of 2% and 5% and tensile strength of 4% and 2% were observed after 28 and 90 days of curing, respectively. It was shown that it is possible to use waste perlite powder as an ingredient in construction polymer–cement composites, while there is a limiting waste content, above which there is a deterioration in mechanical properties.

Synthesis of graphene nanosheets from coffee ground waste and its incorporation to mixed-phase TiO2 as photocatalyst in anthracene degradation

The increasing level of coffee consumption in Indonesia causes a significant amount of coffee ground waste as landfill, leading to serious environmental problems on account of phenol derivatives and acidic compounds as its constituents. Containing high carbon content, waste coffee ground is a favourable biomass candidate to be converted into carbon-based material, such as graphene nanosheet (GN). Having wide surface area, graphene derivatives can be used to modify surface of many materials, such as TiO2. The aim of this study is to synthesize graphene-modified TiO2 with a mixed anatase:rutile phase (9:1) and to analyse its photocatalytic activity towards the photodegradation of anthracene, in comparison with unmodified TiO2. UV-DRS analysis showed a significant decrease in the band gap of TiO2/GN-A (2.78 eV) compared with TiO2 (3.00 eV), leading to an increase in photocatalytic activity (Kt TiO2 = 7.26 × 10-4 min−1; Kt TiO2/GN-A = 3.43 × 10-3 min−1). All in all, the synthesized photocatalyst materials presented promising potential to be applied as photocatalysts in photodegradation of organic compounds.

Eco-friendly 3D printed concrete with fine aggregate replacements: Fabrication, characterization and machine learning prediction

During the last decade, 3D printing technology has experienced significant development, especially for concrete printing in construction. However, eco-friendly 3D printed concrete with fine aggregate replacements has not yet been sufficiently studied. Herein, twenty-five (25) mix categories are designed for use in 3D printed concrete. The mix materials include fine aggregates, silica fume (SF), ground waste rubber tire (Ru), and glass fiber (GF) composites. The mechanical characterization (i.e., stress-strain relations) are investigated, and the mechanical performance (i.e., compressive and flexural strengths) are reported. Numerical simulations are carried out to validate the experimental results, and satisfactory agreements are obtained. Machine learning prediction model is developed using the experimental and numerical results to predict the compressive and flexural strengths of the aggregate-mixed 3D printed concrete. An inverse relationship was observed between the rubber content and compressive strength of 3D printed concrete (RuC) printing imperfections is highly correlated with high rubber content. Similarly, increasing fiber volume in fiber concrete (FC) resulted in a decreased compressive strength due to reduced interlayer bond. Notably, hybridized concrete (HC) exhibited comparable strengths to fiber concretes at 1% fiber content, but a significant strength increase was observed at 5%, 10%, and 15% rubber contents with 2.5% fiber volume. Better stress-strain response (i.e., higher strength) is observed with larger SF content. It is evident that the addition of SF, GF, and Ru to concrete, improves cost efficiency and the stress-strain behavior of 3D printed concrete. The reported eco-friendly 3D printed concrete has a relatively low peak strength compared to normal concrete but shows traces of fatigue resistance. The eco-friendly 3D printed concrete provides the alternative for normal concrete for in-situ construction applications.

Mechanical Properties of Biocomposite Films Based Polyvinyl Alcohol/Potato Starch Filled by Coffee Ground Waste

Mechanical Properties of Biocomposite Films Based Polyvinyl Alcohol/Potato Starch Filled by Coffee Ground Waste

Recycling waste tire rubber through an innovative water-medium ionizing radiation treatment: Enhancing compatibility and mechanical performance

In this research, we solved the compatibility problems of rubber mixtures containing waste ground tire rubber (GTR) with an innovative and environmentally friendly, water-based ionizing radiation treatment, meaning that the GTR is under water. Our hypothesis was that the strong oxidizing agents that appear during the radiolysis of water can activate the surface of the GTR, resulting in reactive functional groups containing oxygen, which can help establish a better interaction between the matrix and the GTR. We treated the GTR using different absorbed doses and examined the changes in the GTR using Soxhlet-extraction and cross-link density measurements. The surface of GTR was characterized by Fourier-transform infrared spectroscopy. Then we prepared GTR-containing natural rubber-based mixtures in an internal mixer, using two different mixing techniques. The mixtures were vulcanized in a hydraulic press, and the mechanical and morphological properties were investigated. As a result of the radiation treatment, cross-link density decreased slightly, while sol content did not change significantly. The FTIR spectra indicated that oxygen-containing groups appeared on the surface of the treated GTR. In the case of one-step vulcanizates, tensile strength increased by 11% and tear strength by 40%, while elongation at break remained high. For the two-step mixtures, tensile strength improved by 25%, tear strength by 35%, while elongation at break was over 400%. An irradiation dose of 20 kGy produced the best result, which is sustainable in mass production.

GC-MS and HPLC Supported Phytochemical Analysis of Tridax

Background: Tridax procumbens (T. procumbens) Linn. is a daisy family commonly known as “Ghamra” or “Coat Buttons”, the native of this plant is tropical America, Asia, Australia and throughout India, it is also distributed in roadside, waste grounds, riverbanks mainly during rainy season. It has medicinal properties due to presence of some bioactive chemical constituents. Objectives: Phytochemical analysis of Tridax procumbens (T. procumbens) Linn leaves were carried out in different extraction. Methods: Qualitative, Quantitative, HPLC, GC- MS & UV-FTIR. Results: The phytochemical qualitative analysis of Tridax procumbens (T. procumbens) Linn was performed with various extraction. The hydro-ethanolic extract contains a high concentration of phytochemical constituents than ethanol, hexane, petroleum ether & aqueous extracts. The phytochemical constituents found were tannin, saponin, flavonoids, steroids, terpenoids, triterpenoids, alkaloids, anthraquinone, polyphenol, glycoside, coumarins and emodin. The wide range of bioactive compounds were found to have antitoxicity, anticancer, antimicrobial, antifungal, antioxidant, antitumor, antimicrobial, antifouling, nematicide, antiarthritic, hepatoprotective, hypocholesterolemic, 5-alpha reductase inhibitor, antihistaminic, anticoronary insectifuge, antieczemic, antiacne, anti-androgenic flavour, pesticide, lubricant, haemolytic 5-alphareductase inhibitor, antipsychotic, potent antibacterial agent, antimalarial activites. Conclusion: Hydro-ethanolic extract showed several phytochemical constituents and bioactive compounds which can be used for therapeutic purposes.

Biomorphological structure of Kemerovo city’s flora

The article presents a range of types of life forms for the flora of the city of Kemerovo and its functional zones, including both native and alien elements. The perennial polycarpic plants have dominated in city’s flora, this tentation is common in Western Siberia. An increase in the proportion of monocarpic plants was revealed with an increase in anthropogenic factor on parts of the city. Human activity changes life expectancy and the number of fruiting as an adaptation to extreme growing conditions. The largest proportion of monocarpic grasses (50.61%) was noted on highways and tramways - the main migration corridors of plants, the proportion of monocarpics above 30% was noted in waste grounds, industrial zone, on railway tracks and stations. The largest proportion of polycarpic grasses was found on rocky outcrops and steppes (68.02 %), as well as on the territory of weakly transformed forests (65.98 %). Rocky outcrops and steppes have the largest proportion of semi-woody life forms (3.55 %) and shrubs (1.52 %) in the flora. The materials obtained during the collection by the method of model areas allow to identify the distinctive features of some functional zones of the city, to identify the most common patterns for the departments of suburban flora and urban flora.

Formulation of inexpensive and green reactive powder concrete by using milled-waste-glass and micro calcium-carbonate – A multi-criteria optimization approach

In view of its high strength and durability, reactive powder concrete (RPC) is a promising construction material. The replacement of cement and silica fume with sustainable alternatives to RPC may provide significant benefits, however, there are challenges to overcome. In this study, calcium carbonate and ground waste glass powder were introduced as mineral mixtures to develop an environmentally friendly and cost-effective RPC mixture. The best flowability, proper compressive strength, and reduced cement content were achieved using a multi-objective simultaneous optimization approach based on the Derringer & Suich methodology. As a result of the study, 603 kg/m3 of cement was determined as the most suitable dosage for RPC. Additionally, the optimized mix contained 368 kg/m3 of waste glass and 118 kg/m3 of calcium carbonate, which had a beneficial impact on both cost and environmental considerations. As a result of numerous experimental tests, including compressive strength, elasticity modulus, chloride ion penetration, and drying shrinkage, the developed RPC's properties were validated and were comparable to the control mixture while showing superior drying shrinkage behavior. A further benefit of adding these admixtures was the reduction of superplasticizer dosage. Despite the optimized RPC's lower mechanical and chloride ion penetration performance at early ages, the performance discrepancy diminished over time due to the pozzolanic properties of waste glass powder. A significant characteristic of the optimized RPC was its superior drying shrinkage behavior throughout the testing period resulting from its reduced water dosage. Ultimately, the study highlights the potential of the addition of calcium carbonate and waste glass powder to RPC for sustainable concrete production at a low cost.