Safe Waste Disposal Research Articles

Study on the Vulnerability of Municipal Solid Waste Resource Symbiosis Network—A Case Study Based on the Construction of Zero Waste City in Panjin

Building zero-waste cities is an important initiative. It helps China to meet the challenges of climate change, build an ecological civilization, and build a beautiful and high-quality China. Through the recycling and safe disposal of waste, the ultimate goal of the construction of zero-waste cities is to minimize the amount of solid waste. Municipal Solid Waste Resource Symbiosis Network (MSWRSN) is the best way to achieve zero-waste cities. However, this system is vulnerable to many factors. These factors will restrict the construction and development of zero-waste cities. This study proposes a vulnerability measurement method of MSWRSN based on energy exchange. Panjin, a city in Liaoning Province, is used as an example to simulate it. The vulnerability measurement method of MSWRSN is composed of three parts. First, the study adopts a directional weighting approach to design the topologic structure of MSWRSN. Second, Dijkstra’s algorithm is used to analyze two topological parameters, node mesonumber and edge mesonumber. It also focuses on single-node failure mode and edge failure mode. Finally, the study uses a functional measure function to calculate the vulnerability of each node and each edge in symbiotic networks. The results of the study show that (1) MSWRSN in Panjin has not yet formed a nested pattern. The symbiotic patterns of different industrial chains are also different. (2) Node failure has a greater impact on MSWRSN. (3) There are differences in the vulnerability of the industry chain in the network. Based on the findings of the study, this study advises managing the vulnerability of MSWRSN from the following aspects. It includes increasing the diversity of symbiotic units, promoting the development of symbiotic networks to nested types, and strengthening risk monitoring and management of core enterprises.

Layout Optimization of Construction Waste Recycling Facilities for Development of New Urban Areas from Centralized and Decentralized Processing Collaboration Perspective

The generation, treatment and safe disposal of construction waste have become major problems in new urban areas of China. And the existing research has not been carried out based on the recycling characteristics of scattered, low efficiency and large negative externalities of construction waste processing in the development of new areas. This research studies the optimal location of construction waste centralized and decentralized processing facilities based on the characteristics of the generation end and the demand side of new urban areas. Firstly, grey relational analysis method is used to determine the location of centralized processing facilities. Then, a multi-objective integer programming model is built by comprehensively considering cost, side effect on society and carbon emissions during transportation, and the optimal location and dynamic adjustment of decentralized processing facilities are determined. Finally, taking the development of a new area in China as an example, the network of construction waste recycling facilities is established to verify the effectiveness of this model. The research results show that the layout strategy formulated with this method can maintain the dynamic optimal layout of the system from the perspective of the whole region, and realize the utilization of construction waste with low cost, low transport carbon emission and low social negative impact. The analysis method system established in this paper is universal, which can provide reference for the relevant government departments to plan the construction waste recycling facility network of the area, and provide guidance for the investment decisionmaking and operation management of related enterprises.

Physicochemical Properties and Leaching Toxicity Assessment of Jarosite Residue

The safe disposal of hazardous waste from zinc hydrometallurgy, such as jarosite residue, is crucial for the sustainable development of the industry. The chemical, structural and morphological properties of jarosite residue from zinc smelting were studied by a combination of various characterizations, and environmental stability was evaluated using the toxicity characteristic leaching procedure (TCLP), Chinese standard leaching tests (CSLT) and long-term leaching experiments (LTLE). Phase composition analysis revealed that zinc ferrite and sodium jarosite were the main phases present in the jarosite residue. TCLP and CSLT analyses indicated that the Zn and Pb contents exceeded their respective toxicity identification standards by more than 30 times and 8 times, respectively, exceeding the threshold values of the standard. The LTLE results demonstrated that Pb concentrations continued to exceed the standard limits, even after long contact times. This study has paramount significance in the prediction of jarosite residue stability and the evaluation of its potential for secondary environmental pollution.

Findings from a streamlined life cycle assessment of PET-bottles for beverage-packaging applications, in the context of circular economy

Economic activity, especially production, is based upon the use of natural resources. This is a fact that affects the growing pressure of the need to implement a sustainable approach to the design, manufacture, and disposal of products, as waste management and disposal have a significant impact on the environment. Therefore, the EU waste management policy aims to reduce the impact of waste on the environment and health and improve the efficient use of resources in the EU. The long-term goal of this policy is to reduce the amount of waste generated and, if generation is unavoidable, to promote its use as a resource, increase recycling and ensure safe waste disposal. These and related solutions are critical, given the growing amount of plastic waste. Under this perspective, the aim of the article was to assess the relevant environmental issues in the production of PET bottles for packaging applications, which can enable a significant improvement in the life cycle environmental profile not only of the analysed material but, also, of the downstream systems in which they are used as such or processed for finished, more complex goods. Results highlighted that, due to the largest contribution (nearly 84 %) to the environmental profile of the bottles' life cycle, a substantial improvement could be achieved by replacing 50 % of the total amount of virgin PET used with recycled PET.

The dominant role of cooperation in fungal community drives the humification process of chicken manure composting under addition of regulatory factors

This study aimed to explore the action mechanism of fungal community on the enhancement of humification during chicken manure composting by regulating the core pathway of carbon metabolism - the tricarboxylic acid cycle. Regulators adenosine triphosphate (ATP) and malonic acid were added at the beginning of composting. The analysis of changes in humification parameters showed that the humification degree and stability of compost products were improved by adding regulators. Compared with CK, the humification parameters of adding regulators group increased by 10.98% on average. Meanwhile, adding regulators not only increased key nodes, but also strengthened the positive correlation between fungi, and network relationship was closer. Moreover, core fungi associated with humification parameters were identified by constructing OTU networks, and the division and cooperation mechanism of fungi were confirmed. Ultimately, the functional role of the fungal community acting on humification was confirmed by statistical means, that was, the fungal community promoting humification was the main group of composting process. And the contribution was more obvious in ATP treatment. This study was helpful to gain insight into the mechanism of regulators addition to advance the humification process, and provided new ideas for the safe, efficient and harmless disposal of organic solid waste.

Gasification characteristics and synergistic effects of typical organic solid wastes under CO2/steam atmospheres

Gasification technology is an effective way to achieve efficient, safe, and resourceful disposal of organic solid wastes (OSWs). Due to the complex sources and variable components of the OSWs, the co-disposal is highly essential. Various typical OSWs, including food waste (cooked rice, CR), agricultural waste (rice husk, RH; sugarcane bagasse, SB), and industrial waste (furfural residue, FR), were selected for this study. The gasification characteristics and synergistic performance were examined in terms of thermal weight loss characteristics under the CO2 atmosphere and gaseous product characteristics under the steam atmosphere. The synergistic indices of performance parameters were introduced to quantify the synergistic effects. The gasification activity of FR was remarkably higher than that of other OSWs. In the co-gasification with CR under the CO2 atmosphere, FR played an excellent positive synergistic effect, but the agricultural wastes played a slight or no synergistic effect. In the steam co-gasification, RH, SB, and FR all promoted the generation of syngas, in which FR showed still significant synergistic effects, with the synergistic indices of H2 yield, syngas yield, CCE, and CGE being 4–12 times higher than those of other blended wastes. The excellent performance of FR in (co–)gasification was mainly attributed to the acidic properties of FR, which was confirmed by comparing the (co–)gasification performance of FR with and without water-washing pretreatment. The work provides guidance for the co-disposal of OSWs in industrial applications.

Recycling of bypass cement kiln dust in the production of eco-friendly roof tiles

Most of the research of building materials companies at present focuses on recycling waste to minimize the cost of their products and for the safe disposal of these wastes. In this work, the by-pass cement kiln dust (BCKD), the dust that is discarded from the kiln system was used for the preparation of roof tiles. It is partially used to substitute clay in percentages from 5% up to 25%. to prepare roof tiles abiding by ASTM C1167 for two objectives, the safe disposal of waste and the production of low-cost roof tiles. The raw materials were assessed by particle size analysis, XRD, and XRF. The mud was poured into moulds with dimensions of 150 * 30 * 25 mm3 and pressed under a pressure of 10 MPa then dried. The dried samples were fired to temperatures 1000, 1100, and 1150 °C with a soaking time of one hour for each temperature. The linear firing shrinkage, water absorption, bulk density, and breaking strength were measured to determine the properties of the fired specimens. The initial rate of absorption and runoff properties were also determined for the optimal samples. The results showed that samples containing 8% and 12% of BCKD waste that fired at 1100 °C and 1150 °C had cold water absorption of 14% and a saturation coefficient of 0.85, both of which were below the maximum values of the standard limits. Furthermore, the measured breaking strength of about 2700 N was much higher than the necessary minimum value. The results showed that samples met the requirements of ASTM 1167 for clay-type roof tiles containing 8% BCKD waste and fired to 1100 °C. For economic and environmental benefits, 1100 °C firing temperature is recommended than 1150 °C. The initial rate of absorption was found to be 2.8 kg.m−2 and the runoff properties were found to be 0.02 mg.l−1, 7.53, 110.5 mg.l−1 for total dissolved solids, pH and total solids respectively.

Some Factors Affecting the Degree of Knowledge of Farmers Related to Methods of Safe Disposal of Agricultural Waste (A Case Study in a Village in Giza Governorate)

Some Factors Affecting the Degree of Knowledge of Farmers Related to Methods of Safe Disposal of Agricultural Waste (A Case Study in a Village in Giza Governorate)

Hepatitis B vaccine delivered by microneedle patch: Immunogenicity in mice and rhesus macaques.

Vaccination against hepatitis B using a dissolving microneedle patch (dMNP) could increase access to the birth dose by reducing expertise needed for vaccine administration, refrigerated storage, and safe disposal of biohazardous sharps waste. In this study, we developed a dMNP to administer hepatitis B surface antigen (HBsAg) adjuvant-free monovalent vaccine (AFV) at doses of 5µg, 10µg, and 20µg, and compared its immunogenicity to vaccination with 10µg of standard monovalent HBsAg delivered by intramuscular (IM) injection either in an AFV format or as aluminum-adjuvanted vaccine (AAV). Vaccination was performed on a three dose schedule of 0, 3, and 9weeks in mice and 0, 4, and 24weeks in rhesus macaques. Vaccination by dMNP induced protective levels of anti-HBs antibody responses (≥10 mIU/ml) in mice and rhesus macaques at all three HBsAg doses studied. HBsAg delivered by dMNP induced higher anti-HBsAg antibody (anti-HBs) responses than the 10µg IM AFV, but lower responses than 10µg IM AAV, in mice and rhesus macaques. HBsAg-specific CD4+ and CD8+ T cell responses were detected in all vaccine groups. Furthermore, we analyzed differential gene expression profiles related to each vaccine delivery group and found that tissue stress, T cell receptor signaling, and NFκB signaling pathways were activated in all groups. These results suggest that HBsAg delivered by dMNP, IM AFV, and IM AAV have similar signaling pathways to induce innate and adaptive immune responses. We further demonstrated that dMNP was stable at room temperature (20°C-25°C) for 6months, maintaining 67±6 % HBsAg potency. This study provides evidence that delivery of 10µg (birth dose) AFV by dMNP induced protective levels of antibody responses in mice and rhesus macaques. The dMNPs developed in this study could be used to improve hepatitis B birth dose vaccination coverage levels in resource limited regions to achieve and maintain hepatitis B elimination.

Modification of edible chitosan/polyethylene glycol films fortified with date palm fruit waste extract as promising antimicrobial food packaging materials for fresh strawberry conservation

In light of the global concern that calls for the safe disposal of waste polluting the environment and its exploitation in adding many distinctive products that can be used practically, this study was conducted to clarify how to make the best use of such waste. Therefore, the presented research aims to eliminate these residues and use their extracts as antimicrobial materials that can be used for films/membranes preparation for food and fruit preservations with low economic feasibility. Based on that, the aim of our work was planned to prepare films of date palm fruit waste extract (DPFW) loaded chitosan (Cs)/polyethylene glycol (PEG) composite. The extract was added to the polymers mentioned above with three different concentrations to prepare three film samples (DPFW-1@Cs/PEG), DPFW-2@Cs/PEG and DPFW-3@Cs/PEG). All these films were compared with those prepared without DPFW (DPFW-0@Cs/PEG). The film solutions films were cross-linked using glyoxal as a crosslinker before films formation. The finding illustrated that, the surface structure of DPFW-loaded Cs/PEG became rough, and the extract was remarkably seen on the surface of Cs/PEG films. In addition, the water contact angle for all fabricated films revealed that the films are hydrophobic in nature. The thermal stability of Cs/PEG films were enhanced with the addition of DPFW. The DPFW extract displayed an impressive suppression effect against the identified pathogens in antimicrobial experiments. As fresh strawberries were preserved using Cs/PEG film loaded with DPFW for 10 days, it was discovered that the strawberry wrapped in the extract-containing films maintained their freshness superior to those wrapped in unloaded material. Such films have a wide range of potential applications in food packaging to extend the longevity of freshly prepared goods due to their simplicity and solid biocidal ability. The present research's findings imply that DPFW-3@Cs/PEG material can be successfully used to pack perishable fruits and vegetables.

Mechanical properties and micro mechanism of alkali-activated tannery sludge/fly ash composite cement-based recycled concrete

In order to alleviate the environmental degradation and resource waste caused by cement production and construction waste disposal, some cement is replaced by tannery sludge and fly ash, and natural aggregate is replaced by recycled coarse aggregate. The preparation of alkali activated tannery sludge/fly ash composite cement-based recycled concrete (AA-SFRC) is of great significance for the safe disposal and utilization of solid waste. In order to study the mechanism of the effect of alkali-activator on the mechanical properties and microstructure of AA-SFRC, six kinds of AA-SFRC with different alkali equivalents (AE) were designed, and the strength tests, nuclear magnetic resonance (NMR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) tests were carried out. On this basis, the influence of AA-SFRC pore structure parameters on strength performance was discussed by using grey entropy analysis method, and a grey model GM (1, 5) prediction model of 28d strength was established. The results demonstrated that with the increase of AE, the AA-SFRC strength increased at first and then decreased, and the tension–compression ratio (Ts/Cs) remained in the normal range, between 0.065 and 0.081. When the AE was 9%, the mineral composition of AA-SFRC reached equilibrium, and the hydration reaction was the most sufficient. The compressive strength and splitting tensile strength reached the maximum. Meanwhile, the pore structure showed that the porosity and the proportion of macro pores were the smallest. The 28d strength of AA-SFRC was greatly affected by its 7d strength, first peak ratio, fractal dimension Dmax and porosity. The average relative errors between the predicted value of GM (1, 5) model and the experimental value were less than 0.03%. This study can provide a reference for the resource utilization of tannery sludge, fly ash and construction waste.

A comprehensive framework towards safe disposal of construction and demolition waste: The case of Egypt

Construction and demolition waste (CDW), produced at various stages of construction projects, is a major problem for the construction industry. This waste has led to an international issue that is widespread and enduring. This research used a quantitative method in two stages to suggest workable options to fix this significant problem. An online survey of Egyptian construction industry professionals was conducted during the first round to gauge how three key factors affected the safe disposal of CDW (SDCDW). Management of route, collection, and transportation (MRCT), determinationof illegal waste dumping sites (DIWDS), and construction waste tracking and scheduling (CWTS)are the three main factors. The development of a comprehensive framework for SDCDW, in support of Egypt's vision 2030, involved multivariate statistical analysis using the structural equation modelling (SEM) method in the second stage. The findings showed that these three factors had a favourable impact on SDCDW in Egypt. This was evidenced through mentioning the acceptable effect sizes of these three factors towards SDCDW; where MRCT showed moderate effect towards SDCDW with a value of 0.16, CWTS showed small effect towards SDCDW with a value of 0.137, and DIWDS showed small effect towards SDCDW with a value of 0.052.The study also discovered that MRCT is more effective in treating SDCDW with a model path coefficient of 0.383. However, DIWDS is the least effective when it comes to SDCDW with a model path coefficient of 0.191. In support of Egypt's Vision 2030, this paper makes concrete suggestions for the government and the construction sector regarding the safe disposal of CDW.

Safe stool disposal and associated factors among mothers of children aged under-two years in Gambia: Evidence from Gambia Demographic Health Survey 2019/20.

Appropriate disposal of child stool is vital in preventing the spread of faecal-oral diseases. According to WHO/ UNICEF Joint Monitoring Program, Safe child stool disposal includes disposing a stool in a Flush or pour-flush toilet/latrine (to a piped sewer system, septic tank, pit latrine), Ventilated improved pit (VIP) latrine or a Pit latrine with slab. The study aimed to assess safe child stool disposal practice and associated factors among mothers with children aged under-two years in Gambia. This study was based on a large community-based cross-sectional survey, conducted from 21 November 2019 to 30 March 2020 in Gambia. The survey employed a two-staged stratified cluster sampling technique to recruit study participants. Descriptive statistics and logistic regression models were used to summarize descriptive data and identify factors associated with safe waste disposal, respectively. A p-value of less than 0.05 and 95% confidence interval were used to determine statistical significance. The prevalence of safe stool disposal among mothers with children aged under-two years were 56.3% (95% CI: 54.6%, 58.1%). Mothers aged 25-34 (AOR = 0.78 (95%CI: 0.62, 0.98)), the highest wealth quintile (AOR = 0.43 (95%CI: 0.33, 0.56)), being exposed to media (AOR = 1.37 (95%CI: 1.07, 1.76)), increasing age of children (AOR = 1.06 (1.05, 1.07)), Being employed (AOR = 1.31 (1.11, 1.55)) and Geographic region were significantly associated with safe child disposal practice. The prevalence of safe child stool disposal was low in Gambia. Age of the mother, age of the child, region, wealth index, media exposure and occupational status of the mother were significantly associated with safe child stool disposal. Public health intervention strategies designed to promote safe child stools disposal need to conduct thorough community assessments to identify community-specific facilitators, needs and barriers. Additionally, public health experts and policy makers should take into consideration the geographical and wealth inequalities when designing programs aimed to improve safe child stool disposal practice.

Investigating the effect of pore water composition and isosaccharinic acid (ISA) on sorption of Pu to a CEM III/C-based mortar

In the frame of the safe disposal of short-lived low and intermediate level nuclear waste (SL-ILW), ONDRAF/NIRAS (Belgium) has submitted a license application for the exploitation of a near surface facility in Dessel (Belgium). A significant part of the waste intended for the surface repository is Pu-contaminated and has been conditioned by means of CEM III/C based mortar, produced in the CILVA-installation at the Belgoprocess site in Dessel. To establish more accurate data on sorption of Pu to the CILVA mortar, an experimental test set-up was designed in order to screen which factors were likely to affect Pu sorption to the mortar. The different factors of the design were variables related to the pore water composition of the mortar on the one hand (concentrations of Ca2+, Cl−, SO42−, S2−, K+ and OH− (pH)), and variables characteristic for batch sorption experiments on the other hand ([Pu], solid-to-liquid ratio and equilibration time). The results of this screening indicate that over the tested variables, only the concentration of Ca2+ in the synthetic pore water affects Pu sorption to the CILVA matrix to a significant extent. Additionally, from literature it is expected that the presence of isosaccharinic acid (ISA), a cellulose degradation product, would affect Pu sorption, with increasing concentrations of ISA frequently correlated with decreased sorption. To address the nature and extent of the impact of both [Ca2+] and [ISA] and their combined effect on sorption of Pu to the mortar, an experimental set-up for surface response measurement (SRM) was designed. A Central Composite Design (CCD) in two factors was selected for the SRM, with three test points and a four point repetition of the centre point. The execution of this experimental set-up and the resulting responses, allowed for the development of a polynomial model to predict the average response of Pu sorption (expressed as Rd) as a function of [ISA] and of [Ca2+]. In addition, the [Ca2+] in solution in equilibrium with the mortar could be assessed from the established dataset, which allowed to predict Pu sorption as a function of [ISA] at the intrinsic [Ca2+] in the mortar’s pore water.

An Overview of the Mechanical and Tribological Characteristics of Non - Ferrous Metal Matrix Composites for Advanced Engineering Applications

The ever increasing service requirement of industries like automobile, aerospace, marine, infrastructure and transportation have evolved non-ferrous metal matrix composites with different combinations of ceramic and soft reinforcements which have resulted in the improvement of their tribo-mechanical properties as compared to an unreinforced alloy. Secondary reinforcements provide safe disposal of agro-industrial waste thereby reducing environmental degradation. The scanning electron micrographs reveals fairly uniform dispersal of reinforcement in metal matrix if proper conditions are maintained and porosity levels are found to be in acceptable range. The density, hardness, wear resistance, tensile strength, fatigue strength and impact strength of non-ferrous composites have been found to be either comparable or superior to an unreinforced alloy with minimum weight and cost. The purpose of current study is to explore the nonferrous composites and propose their application area based on material properties. An attempt has been made for indepth review on the effect of controllable process parameters on tribo-mechanical properties of the non-ferrous composites. The study concludes that non- ferrous composites with single or more than one reinforcement have superior tribo-mechanical characteristics making them suitable for design of high performance, low cost and low weight to strength ratio components.

A Study on Biomedical Waste Generation Rate in South, East Zones of Hyderabad

Waste disposal is especially important when it comes to medical supplies, as some waste can be contaminated with diseases and dangerous pathogens. Not all biomedical waste is treated the same way and different disposal companies use different methods such as autoclaving, incineration, chemicals and microwaves. Improper disposal of medical waste causes environmental pollution, unpleasant odours, the growth and reproduction of insects, rodents and nematodes, and injuries from blood-contaminated sharp objects, typhoid fever, cholera, hepatitis, etc. can lead to disease transmission. Safe and sustainable disposal of biomedical waste (BMW) is a social and legal responsibility of all those who support and fund medical activities. Effective BMW Management (BMWM) is essential for healthy people and a clean environment. The basic principle of (BMWM) is source separation and waste reduction. We also need to do a lot of research and development in the field of developing eco-friendly medical devices and BMW disposal systems to achieve a greener and cleaner environment. This study will reveal the current processes and environmental impacts of biomedical waste management by examining the quantity and quality of biomedical waste (BMW) generated by pharmacies, laboratories and multiple speciality hospitals.

Conceptual design and simulation study of an autonomous indoor medical waste collection robot

Solid waste management is one of the critical challenges seen everywhere, and the coronavirus disease (COVID-19) pandemic has only worsened the problems in the safe disposal of infectious waste. This paper outlines a design for a mobile robot that will intelligently identify, grasp, and collect a group of medical waste items using a six-degree of freedom (DoF) arm, You Only Look Once (YOLO) neural network, and a grasping algorithm. Various designs are generated before running simulations on the selected virtual model using Robot Operating System (ROS) and Gazebo simulator. A lidar sensor is also used to map the robot's surroundings and navigate autonomously. The robot has good scope for waste collection in medical facilities, where it can help create a safer environment.

Prevalence and Risk Factors of Hepatitis C Viral Infection Among Pregnant Women at a Tertiary Institution in Lagos, Nigeria

Hepatitis C viral infection is a blood borne disease caused by Hepatitis C virus (HCV). It is significantly associated with morbidities and mortalities in men and women. Infection mostly occurs via contact with blood from transfusion of unscreened blood as well as blood products, illicit parenteral drug use (sharing of injection needles), unsafe health care and injection practices. Women who are pregnant and their unborn babies and infants are among the group of people less commonly talked about when the disease burden of HCV is being discussed in Nigeria. This study therefore aimed to ascertain the prevalence of hepatitis C virus infection among the pregnant women as well as the risk factors associated with the acquisition of the infection. Four hundred consenting antenatal attendees at the Lagos Island Maternity hospital, Nigeria were recruited and their blood samples were taken for analysis. A pretested and validated semi structured questionnaire was used to obtain information on risk factors for Hepatitis C Virus infection and socio demographic characteristic of participants. Univariate analysis was performed to obtain proportions and frequencies. In order to uncover additional risk variables for HCV infection, bivariate data analysis was carried out. Chi-square test was performed to assess statistical significance which was assumed at 0.05%. The mean age of the study subjects were 30.6 years with a standard deviation of ± 5.0 years. Majority of the study subjects 133 (33.2%) were in the age group of 30-34, most of them 238 (59.5%) had tertiary education, 396 (99.0%) were married, 110 (27.5%) were traders and 329 (82.3%) were of monogamous family setting. There was an overall sero-prevalence of 1.5% among the pregnant women with a higher prevalence of 1.25% among pregnant women who had more than one delivery (multiparous women) and 0.25% among pregnant women who had no previous delivery (nulliparous women). The risk factors that were significantly associated with the transmission of HCV infection included “Tattoo/Scarification (P=0.002) and “sharing of sharps and needles” (P=0.015). There is the need for effective public education on the ways of spread of HCV virus, practice of universal precautionary measures, adequate sterilization of instruments, appropriate use of injections, safe disposal of waste and sharps and avoidance of other high risk behavior that may lead to HCV infection. A more lager studies on the epidemiology of HCV infection is needed to inform health policy makers on strategies for prevention, screening, control and treatment of HCV infection.

Sustainable valorization of waste keyboard keys via microwave assisted pyrolysis over Fe-Ni doped green catalyst towards clean fuel production

ABSTRACT The technological evolution of electronic equipment in the field of computers and household appliances, along with shorter life of most items, is creating a great concern for managing this waste stream. The main aim of the present investigation was to convert waste keyboard keys into high-quality pyrolysis oil using a microwave catalytic pyrolysis process. Iron (Fe), Nickel (Ni), were doped in different ratios on Biochar (BC) by wet impregnation method, and it was used as a green catalyst for clean fuel production. Initially, a non-catalytic pyrolysis process was conducted and found a maximum pyrolysis oil yield of 49.6 wt.%. Further, microwave catalytic pyrolysis was conducted with variable amount of metal loading and found that highest oil yield of 61.33 wt.% was achieved using 15%Fe-5%Ni/BC catalyst due to the presence of a higher quantity of iron. The produced pyrolysis oil at this condition consists of 45.07% single-ring compounds and reduced the undesirable polycyclic aromatic hydrocarbons (PAHs) in the pyrolysis oil. This work provides a pathway for preparing green catalysts and safe disposal of electrical and electronic plastic waste with better resource recovery.

Effect of PET Resin as Cement Substitute on Properties of Cement Mortar Subjected to Different During Conditions

Polyethylene terephthalate (PET) has many advantageous properties required for the packaging industry. However, the safe disposal of PET waste is an environmental challenge. The present study investigates the feasibility of using PET resin prepared through glycolysis in polypropylene glycol (20:80 and 30:70 PET-to-glycol ratios) as a replacement for cement (5%, 10%, and 15%) in cement mortar. The effect of PET resin with melamine-formaldehyde as a hardener replacement on the consistency, setting time, soundness, compressive strength, tensile strength, and abrasion resistance was experimentally studied at two different curing conditions viz. under water curing and oven-dry curing. Findings of the present investigation infer that the compressive, tensile strength, and abrasion resistance improves upon oven-dry curing. The study concludes that the use of PET resins improves the attributes of cement mortar and at the same time provides an environmentally friendly way to dispose of the PET waste.