Pressmud compost is an organic soil amendment and a robust technology that has potential to restore toxic metals (TMs) polluted soil. The application of organic amendments including pressmud compost ...in soil for toxic metals (TMs) alleviation have gained considerable attention as compared to traditional methods among the scientific community. In this review paper, we summarized the literature aiming to understand the immobilization efficacy of TMs such as cadmium, lead, chromium, copper, nickel, iron, zinc, and manganese, underlying mechanisms, plant growth, essential nutrients and soil health under pot, field and incubation conditions which has not been well investigated up-to-date. The application of pressmud compost at 10 t ha−1 rate has shown highly potential to reduce the bioavailability and bioaccumulation of TMs in the polluted soil. The immobilization mechanism of TMs in soil depends on soil pH, soil type, cation exchange capacity, hydraulic conditions, nutrients dynamics and soil properties. The application of pressmud compost integrated with biochar, compost, rock phosphate, farmyard manure, bagasse ash, molasses immobilized the cadmium, lead, copper, chromium, nickel and zinc in alkaline polluted soil, whereas pressmud compost combined with poultry manure and farmyard manure increased the bioavailability of lead, cadmium, cobalt, chromium, copper, zinc, iron and manganese in acidic soil, it could be due to aging of pressmud compost, application rate, metal type, nature of soil, particle size, application method, plant type and agronomic practices. There is a lack of knowledge on the phyto-management of arsenic, mercury and boron in soil amended with pressmud compost. Future studies must be focused on potential of pressmud compost co-amended with minerals, modified biochars and nano-material for immobilization of TMs in polluted soil-plant through machine learning/artificial intelligence in order to reduce the health risks and improve public health safety in urban and rural areas.
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•Potential of pressmud compost on reducing toxic metals and enhance nutrients in soil was reviewed.•Pressmud compost has potential to reduce bioavailability of toxic metals at 10tons/ha.•Plant growth and nutrients availability was increased with pressmud compost application.•Pressmud compost has positive impact on soil health and control pollution.•Pressmud compost can be used with minerals, modified biochars and nano-material for control pollution.
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•Effect of heating sources on oil yield from waste pyrolysis is studied by big data.•Machine learning regression model is developed to predict oil yield.•Microwave heating is the most ...efficient method among the 4 heating sources.•Order of importance of key pyrolysis parameters affecting oil yield is provided.•Heating source and heating rate should be optimized to achieve max oil yield.
This work emphases the influence of using different heating sources (direct thermal, solar, infrared, microwave heating) on the pyro-oil yield. The effect of the dominating process parameters, namely the heating rate and final temperature, are thoroughly discussed with respect to the heating and reaction mechanism involved. Emphasis is then placed on reviewing the application of microwave (MW) heating in pyrolysis as a relatively new technology with many promising features, particularly the little-known mechanisms of MW heating, new MW heating pattern and pathway using MW absorbents for pyrolysis of waste materials. Machine learning (ML) techniques were then used to statistically analyze the 182 observations in 59 pyrolysis cases obtained from previous pyrolysis practices. The ML linear regression model was developed to predict oil yield by five input variables (feedstock type, feedstock size, heating rate, final temperature, and heating source), which can be used as a guideline for pyrolysis production management. By comparing three heating sources (direct, solar and MW), MW heating is found to be the most efficient method to achieve the highest oil yield. The Decision Tree Analysis demonstrates that the importance order for key variables is as: Log feedstock size > Log heating rate > Heating rate > Temperature > Feedstock size > Heating sources > Feedstock type. Future work should focus on optimizing the heating method and heating rate to achieve optimal yield and quality of pyro-oil. The findings are envisaged to be useful for scaling up the pyrolysis of waste materials for industrial energy applications.
Recent studies on the exploration of eco-friendly approach by utilizing large-scale waste materials as potential catalyst in biodiesel production have attracted much attention. The development of ...heterogeneous catalysts especially from calcium has gained much awareness due to the large availability of calcium-rich waste materials and their corresponding high catalytic activity in the transesterification of oil. Most of the waste materials employed as heterogeneous catalysts have an abundance of natural Ca content and they have high catalyst activity and selectivity despite being environment-friendly and cost-effective. Heterogeneous catalysts with high activity can be produced from Ca based waste materials when calcined at high temperatures. This review gives a brief overview of the developments of various Ca based catalysts derived from waste materials as an efficient catalyst for biodiesel production with significant yield. Industrial wastes (red mud, slag, ash) and biological catalysts (chicken eggshells, mollusk shells, animal bones) possess enormous potential towards developing an economical catalyst and subsequently, low-cost biodiesel generation. However, future challenges await a better utilization of useless wastes into a useful resource to satisfy human needs.
•Calcination temperature above 700 °C is vital for high surface area catalyst.•Chicken eggshell is an efficient catalyst for Jatropha and Karanja oil conversion.•Calcined animal bones transform into HAP as highly active support for catalyst.•Waste fish scale derived catalyst is a low cost catalyst with excellent reusability.•THF as co-solvent in methanol accelerates the reaction kinetics.
This study focuses on developing fiber-reinforced geopolymer concrete (GPC) for 3D printing, utilizing construction waste materials and polypropylene fibers. The GPC, reinforced with 0.8 %, 1.0 %, ...and 1.2 % polypropylene fibers by volume, underwent comprehensive testing, including rheological, mechanical, and microstructural analyses for lab-cast and 3D-printed samples. The results indicated that the 0.8 % polypropylene fibers enhanced flexural and tensile strengths by 8.2 % and 71.7 %, respectively, albeit decreasing compressive strength by 26.2 %. Higher polypropylene percentages led to adverse effects on material properties. Microscopic analysis revealed the formation of voids around fibers and features associated with incomplete hydration. The study emphasizes the need for optimizing water content and the use of longer polypropylene fibers. It also highlights the benefits of using GPC in the 3D printing of structural components.
•Polypropylene fiber-reinforced geopolymer concrete (GPC) for 3D printing was studied and analyzed.•Identified the optimal fiber content of 0.8 % by volume that enhances the GPC’s mechanical properties the most.•Demonstrated increased flexural toughness in GPC, indicating improved energy absorption and ductility.•Disclosed that increasing PP fiber content above 0.8 % reduces GPC’s mechanical properties.•Employed SEM to analyze microstructural changes as a result of PP fiber incorporation in GPC.
•Comprehensive review on integrating waste materials in pre-foamed concrete.•Utilization of different types of waste as cement and aggregate substitute.•Effect of various types of waste materials on ...properties of foamed concrete.•Foamed concrete is a promising avenue to incorporate waste materials for sustainability.
Several million tons of different types of wastes are generated every year globally and this is expected to increase in the future. Most of these wastes are dumped via landfilling or incineration which creates environmental concerns. One of the possible methods of utilizing these wastes is by incorporating them as alternatives to common concrete constituents. In this regard, foamed concrete could provide an excellent medium for incorporating these wastes in a large volume primarily due to low strength requirement of foamed concrete. A significant number of research is carried out to explore the idea of integrating waste materials in pre-foamed concrete. However, the limited knowledge available to recognize the utilization of these waste and the influence on foamed concrete limits the adoption of the concept and further development. Hence, this paper compiles and reviews the usage of various types of wastes such as industrial, agricultural, quarry, and construction industry wastes as a potential replacement for cement and fine aggregate in foamed concrete. Due to the unique composition and the resulting chemical and physical properties, as well as the nature of replacement (either as cement or fine aggregate replacement), each type of waste contributes differently to the performance of foamed concrete. Generally, a non-load bearing foamed concrete with low thermal conductivity, low density, and adequate compressive strength can be produced by incorporating the waste materials. This paper also describes the advantages of incorporating waste materials in foamed concrete compared to conventional concrete and proposes the further development of the concept for future application of a more sustainable and eco-friendly foamed concrete.
•Hydrogen serves as an alternative fuel with the potential to replace fossil fuels.•Thermo-catalytic plastic waste conversion to hydrogen offers a promising solution.•Plasma-assisted gasification ...outperforms the rest of the thermo-catalytic routes.•Pyrolysis, pyrolysis-air gasification, pyrolysis-steam reforming were discussed.•Pyrolysis- (CO2) dry reforming and pyrolysis-plasma catalysis methods were elaborate.
Hydrogen is an energy carrier that can be utilized in various applications, including power plants, the synthesis of high-value products, and clean transportation fuels without emissions. Hence, hydrogen is a potential candidate that can replace fossil fuels and reduce environmental pollution. The high demand for plastics is driving the plastics production rate to increase yearly, leading to a great accumulation of plastic waste materials resulting in a severe burden on the environment. Thermo-catalytic conversion of plastic waste materials to hydrogen and other high-value fuels is a promising route that can efficiently provide an ideal long-term solution necessary to overcome this environmental challenge. Developing durable and high-efficiency catalysts that can immerge hydrogen production from plastic wastes on the industrial scale is still a potential challenge for researchers. This study comprehensively summarizes and discusses the recently published literature for hydrogen production from plastic waste materials using different thermo-catalytic processes, including pyrolysis, pyrolysis-air gasification, pyrolysis-steam reforming, pyrolysis- (CO2) dry reforming, and pyrolysis-plasma catalysis. The scope of this review is to focus on the influence of catalysts and supports, catalysts synthesis method on the production yield of hydrogen, and the impact of several crucial reaction parameters like pyrolysis temperature, catalytic temperature, a catalyst to plastic, and steam to plastic ratios is inclusive in this review as well. The conclusions of this review study will be extremely valuable for researchers interested in the sustainable generation of H2 from plastic waste materials.
•We have provided information regarding bitumen and its adverse impact to the human life and environment.•We present the prospect of alternative binders that can be used to reduce the use of ...bitumen.•We have proved that, use of bio oil, polymer and waste cooking oil can be an effective alternative by literature review.•We provide instructions about the criteria and experimental method to do further study for future research.
Bitumen (asphalt) is viscoelastic, rheological and non-magnetic material composed of heavy hydrocarbons with low dielectric constant (ε′). It is a by-product of petroleum oil refinery. Though it is used as a binder for flexible pavement all over the world, it has severe environmental impacts. Bitumen is non-hazardous at room temperature but when heated at 165–200°C, it becomes toxic. Consequences, such as environmental degradation, depleting petroleum reserves and price-spiking, led researchers to explore alternative sources of obtaining binder for pavement. This paper provides an overview of the probable materials that could be used as an alternative binder. The materials obtained from bio-based sources, such as bio-oil, polymer, plastic, rubber and waste cooking oil and retrieved from waste material show promise and discussed. Further research is needed to make them satisfactory replacement of bitumen on an industrial scale, and be a sustainable source of binder for flexible pavement.
Grass waste was used for transform an inexpensive waste into health. Silver nanoparticles (AgNPs) have been synthesized using waste material (dried grass). The average size of silver nanoparticles ...observed in transmission electron images was estimated to be about 15 nm. The anticancer, antifungal and antibacterial effect of AgNPs were studied in vitro. The minimum inhibitory concentration of AgNPs against Pseudomonas aeruginosa and Acinetobacter baumannii was calculated about 3 µg/ml. The highest level of inhibitory effect of AgNPs against Fusarium solani was close to 90% at a concentration of 20 μg/ml of AgNPs. An inhibitory effect on the cancer cell growth is reach, by increasing the concentration of AgNPs to 5 µg/ml; the cancer cells' survival decreases about 30%. Western results showed that the expression of Cyclin D1 protein of MCF-7 cell line decreased after treatment with the effective concentration of AgNPs.
The implementation of a building construction project is unavoidable from the emergence of waste material. Construction material waste is defined as something that is over what is required. This ...study intends to find the application of construction waste management in building construction projects to minimize the waste material. Data was collected using observation, interviews, and distributing questionnaires to 4 building project parties in Central Java using a random sampling method. Data analysis was carried out by descriptive analysis to determine the type and cause of the highest waste material and supported by regression and correlation analysis to assess the application of ways to minimize waste material. The results of data analysis show that the most types of waste material are formwork wood, reinforcing steel, concrete, and cement. The factor causing waste material that most often occurs is the design change factor that comes from the design phase. Based on the analysis, the effort to minimize waste material that is the most influential on it is improving the quality of tool and material management by providing training to construction personnel related to materials construction used
Pectin is one of the finest natural polymer which has drawn great attention because of its applications in different fields. Due to the quintessential structure of pectin, it can be transformed into ...variety of useful products. It can be utilized as a blend in many polymers to make a mixture or a composite material. Owing to considerable collection in chemical conformation and cross-linking mechanism, different pectin based hydrogels have been prepared for different characteristics in pharmaceutical and bio-medical sites. Inventive properties of hydrogels like volubility, swellability, solvability and hydrophilicity make them better alternative for wastewater treatment. Recently, pectin based hydrogels have demonstrated excellent performance to eliminate various metal ions and dyes from the polluted water. The adsorption characteristics of pectin based hydrogels can be upgraded by using nanoparticles, which prompts to the development of hydrogel nano-composites. In this review article, we have summarized a comprehensive assessment in the direction of using pectin based hydrogels to remove toxic pollutants from aqueous solution. Sodium acrylate-co-N-isopropylacrylamide based pectin hydrogel has demonstrated the maximum adsorption capacities of 265.49, 137.43, 54.86, 53.86, 51.72 and 50.01 mg g−1 for the adsorption of methyl violet, methylene blue, Pb(II), Cu(II), Co(II) and Zn(II) respectively. We have also discussed the pectin structure, properties and applications in this article.
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•Hydrogel is used as sustainable noble material.•Structure and properties of pectin are described.•Pectin is produced from bio-waste materials.•Pectin based hydrogels are used in water purification.•The mechanical strength of pectin based hydrogel can be improved by incorporation of nanoparticles.
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