Solid Handling Research Articles

Microbial flora of the respiratory tract and skin of artisanal municipal solid waste handlers in Aba, Abia State, Nigeria

Municipal solid waste handling carries occupational risk for waste handlers due to exposure to diverse microorganisms and hazardous substances that cause respiratory and skin infections. A cross-sectional study was carried out, and 150 respondents were recruited using a simple random sampling technique. The sociodemographic characteristics, health-related complaints, health-seeking behaviour and the bacterial and fungal microflora of the respiratory tract and skin of artisanal municipal solid waste handlers and some controls in Aba, Nigeria, were determined using a mixed methods research design, involving the use of interviewer-administered structured questionnaires and conventional culture techniques. We analysed the data using IBM SPSS version 25. The results are presented in tables as frequencies and percentages. The majority of artisanal municipal solid waste handlers in Aba are male (95%). Their mean age is 30 years, and the age group of 21–40 years constitutes the highest proportion (65%) of the workforce. Health-related complaints were higher (95%) among the waste handlers compared to the control subjects (4%). The findings show a high prevalence of respiratory (57%), eye (34%) and skin (87%) complaints among the waste workers, compared to 6%, 0% and 2%, respectively, among the control subjects. Seventy-eight (78%) of the waste handlers indulge in self-medication via over-the-counter (OTC) drugs; 17 (17%) access diagnostic laboratories and only 4 (4%) visit hospitals for treatment, as compared to the control subjects, who recorded 1 (2%) for OTC drugs, 46 (92%) for laboratories and 2 (4 %) for hospitals. Acquisition (15%) and use (3%) of personal protective equipment (PPE) were very low amongst the waste handlers. A total of 704 bacterial isolates and 191 fungal organisms were isolated from the study subjects. Among the waste handlers, the percentage distribution of bacteria was almost the same at both sites: respiratory tract, 241 (49.9%) and skin, 242 (50.1%), compared to the control subjects’ respiratory tract, 105 (47.5%) and skin, 116 (52.5%), which showed a slight difference between the sites. S. epidermidis (24%) and B. cereus (13%) were predominant in the respiratory tract, whereas S. aureus (29%) and S. epidermidis (19%) predominated the skin of the waste handlers. Similarly, S. aureus (34.3%) and B. cereus (20.9%) were predominant in the respiratory tract, while B. cereus (37.9%) and S. epidermidis (18.1%) predominated the skin of the control subjects. Candida spp. was the most predominant fungus in the respiratory tract (81.4%) and skin (42.9%) of the waste handlers, as well as in the respiratory tract (85%) and skin (78%) of the controls. The presence of the isolated bacteria and fungi in increased proportions in the waste handlers may be attributed to occupational exposure through direct contact with waste, inhalation of organic dust laden with biological agents and the poor working conditions of the waste handlers. Health education and improvements in working conditions are necessary to mitigate the occupational challenges of waste handlers.

A miniaturized feedstocks-to-fuels pipeline for screening the efficiency of deconstruction and microbial conversion of lignocellulosic biomass.

Sustainably grown biomass is a promising alternative to produce fuels and chemicals and reduce the dependency on fossil energy sources. However, the efficient conversion of lignocellulosic biomass into biofuels and bioproducts often requires extensive testing of components and reaction conditions used in the pretreatment, saccharification, and bioconversion steps. This restriction can result in a significant and unwieldy number of combinations of biomass types, solvents, microbial strains, and operational parameters that need to be characterized, turning these efforts into a daunting and time-consuming task. Here we developed a high-throughput feedstocks-to-fuels screening platform to address these challenges. The result is a miniaturized semi-automated platform that leverages the capabilities of a solid handling robot, a liquid handling robot, analytical instruments, and a centralized data repository, adapted to operate as an ionic-liquid-based biomass conversion pipeline. The pipeline was tested by using sorghum as feedstock, the biocompatible ionic liquid cholinium phosphate as pretreatment solvent, a "one-pot" process configuration that does not require ionic liquid removal after pretreatment, and an engineered strain of the yeast Rhodosporidium toruloides that produces the jet-fuel precursor bisabolene as a conversion microbe. By the simultaneous processing of 48 samples, we show that this configuration and reaction conditions result in sugar yields (~70%) and bisabolene titers (~1500 mg/L) that are comparable to the efficiencies observed at larger scales but require only a fraction of the time. We expect that this Feedstocks-to-Fuels pipeline will become an effective tool to screen thousands of bioenergy crop and feedstock samples and assist process optimization efforts and the development of predictive deconstruction approaches.

Technical Assessment Of Mud Handling Planning With Dredger Pump In Mining Front Area Of Pt. Makmur Lestari Primatama, Southeast Sulawesi, Indonesia

The high intensity of rain can affect mining activities because rainwater will be collected and stored in the area with the lowest elevation. In mining areas that have the lowest elevation point, namely the pit area, this will have an impact on mining activities. The pit area will not be disturbed if water or eroded slopes will enter and be accommodated in well-made drainage and vice versa if drainage is not formed properly, water and mud will be retained and accommodated in the pit area. If the water and mud are left unchecked, the water will overflow and mining will be temporarily halted, affecting the previously planned mining system. In this case, the pit whose water has been pumped out leaves the mud at the bottom of the pit trapped, so action is needed to remove the mud from the pit area and the need for qualified tools according to the existing mud criteria. The mud at PT Makmur Lestari Primatama has an SG criteria of 1.39 (top elevation mud) - 1.5 (bottom elevation mud) with mud grains of 0.005mm to 2mm, it can be concluded that the mud has liquid mud criteria to hard mud. So that the determination of a tool to be able to move mud using a pump, the selection of this pump There are three important parameters: Grain size, Specific Gravity, and also variations in material concentration that must be considered because they can affect the total head or flowrate. The difference between the Slurry pump and the dredger pump is in the pumping process, the dredger pump is able to pump hard mud with the help of a little water while the slurry pump is difficult to pump hard mud because it requires quite a lot of water to pump it. Therefore, a dredger pump is chosen to move the mud in the mining area so that it can pump liquid mud to hard mud, the selection of this dredger pump is based on pump specifications including max capacity 120-200m3/h, solid handling 35mm - 60mm, speed 1180 RPM, and effieciency 46%-51%. The planning analysis of the use of dredger pumps uses the Bernoulli equation and the amount of mud that must be pumped using the USLE method. Based on the results of a series of studies that have been carried out, researchers found that the total potential erosion is 8,574.2 tons/year, the total actual erosion is 7,716.8 tons/year, and the total volume of mud that must be pumped is 5,074.86m3 with a slurry weight of 1,448.2 kg/m3. So the most ideal dredger pump for this purpose is Dragflow HY85A with a capacity of 210m3/h, pumping hours of 16.6 hours / day, pumping duration of 2 days 15 hours and efficiency of 40% using HDPE type 10 inch diameter pipe.

Energy assessment and heat integration of biofuel production from bio-oil produced through fast pyrolysis of sugarcane straw, and its upgrading via hydrotreatment

Sugarcane processing is one of the most important economic activities in Brazil, producing ethanol and sugar for domestic and international markets. Utilising the lignocellulosic residues of this industry, specifically bagasse and straw, would increase the second-generation biofuel production without increasing the sugarcane planted area. Among the processes available, the fast pyrolysis is a thermochemical conversion process that produces mainly bio-oil, a liquid with several advantages over solid biomass, regarding transportation, pumping, storage, and handling. Moreover, the bio-oil can be upgraded to obtain biofuels of higher added-value. Among feasible upgrading technologies, the hydrotreatment is one of the most promising methods for eliminating the reactive functionalities of the bio-oil by removing oxygen or cracking large molecules in the presence of hydrogen; however, this comes at the expense of a significant hydrogen consumption. Thus, the aim of this study is to evaluate the biofuel production through the fast pyrolysis of sugarcane straw, followed by the upgrading of the produced bio-oil via hydrotreatment. The evaluation is carried out by way of energy and mass balances of the processes, performed using the software Aspen Plus. Furthermore, the possibilities of integrating the bio-oil production and upgrading into the conventional ethanol and sugar production process will also be assessed through heat integration, applying the Pinch analysis. Results showed the potential for renewable gasoline and diesel production with yields of 0.086 kg/kg of dry straw and 0.08 kg/kg of dry straw, respectively. Additionally, integrating the pyrolysis process, including the bio-oil upgrading, into the ethanol production process can achieve a liquid fuel production (ethanol, gasoline and diesel) of 2289.8 MJ/t cane, which represents an increase of 29 %, while the surplus electricity increases in 5.3 %, when compared to the conventional ethanol production plant.

Ultrasonic measurement of fill volume of bulk solids in discharge vessels

In bulk solid handling, measuring the fill volume of vessels with powders is complex due to the uneven material surface. This research presents a method using an array of narrow-beam ultrasonic range finders in a powder discharge vessel. The vessel's cross-sectional area was divided into equal sub-sections, each measured by a range finder. The total fill volume was calculated by summing up the volumes of these sections. This system allows quick volume estimates at around 0.9 Hz under various flow states. In static conditions, tests on flat, concave, and convex powder surfaces showed a volume discrepancy of <5% of vessel capacity. For a vessel discharging polyethylene pellets, the estimated fill volume was under 0.6% uncertainty (confidence interval: 0.95). The findings underscore the utility of ultrasonic range finders for accurate volume determination in powder discharge vessels.

Vibrational manipulation of dry granular materials in lab-on-a-chip devices.

We present vibrational techniques to pump, mix, and separate dry granular materials using multifrequency vibrations applied to a solid substrate with a standard audio system. The direction and velocity of the granular flow are tuned by modulating the sign and amplitude, respectively, of the vibratory waveform, with typical pumping velocities of centimeters per second. Different granular materials are mixed by combining them at Y-shaped junctions, and mixtures of granules with different friction coefficients are separated along straight channels by judicious choice of the vibratory waveform. We demonstrate that the observed velocities accord with a theory valid for sufficiently large or fast vibrations, and we discuss the implications for using vibrational manipulation in conjunction with established microfluidic technologies to combine liquid and dry solid handling operations at sub-millimeter length scales.

Burden of Solid Waste, and Control Measures for Health Hazards Emanating from Its Mismanagement in a Populous Country Like India; with Special Reference to Odisha Slums and Rural Areas

The article summarizes the growing burden of solid wastes across the world and closer in relation to the Bhubaneswar city. Rapid urbanization and human habitation is not matched with efficient solid waste handling and disposal. This is posing a serious threat to environment and even becoming the root cause of spread of infectious diseases as well as reemerging diseases. The review opens up the pandora box of the types of waste, how they need to be segregated and legislations and policies that have evolved to manage this issue. Of late newer forms of solid waste like e-waste and construction waste are also being added. A wide public as well as political awareness and urgent action is needed to prevent environmental damage and calamities.

Main outcomes of the Phebus FPT1 uncertainty and sensitivity analysis in the EU-MUSA project

The Management and Uncertainties of Severe Accidents (MUSA) project was funded in HORIZON 2020 and is coordinated by CIEMAT (Spain). The project aims at consolidating a harmonized approach for the analysis of uncertainties and sensitivities associated with Severe Accidents (SAs) analysis, focusing on source term figures of merit. The Application of Uncertainty Quantification (UQ) Methods against Integral Experiments (AUQMIE – Work Package 4 (WP4)), led by ENEA (Italy), was devoted to apply and test UQ methodologies adopting the internationally recognized PHEBUS FPT1 test. FPT1 was chosen to test UQ methodologies because, even though it is a simplified SA scenario, it was representative of the in-vessel phase of a severe accident initiated by a break in the cold leg of a PWR primary circuit.WP4 served as a platform to identify and discuss the issues encountered in the application of UQ methodologies to SA analyses (e.g. discuss the UQ methodology, perform the coupling between the SA codes and the UQ tools, define the results post-processing methods, etc.). The purpose of this paper is to describe the MUSA PHEBUS FPT1 uncertainty application exercise with the related specifications and the methodologies used by the partners to perform the UQ exercise. The main outcomes and lessons learned of the analysis are: scripting was in general needed for the SA code and uncertainty tool coupling and to have more flexibility; particular attention should be devoted to the proper choice of the input uncertain parameters; outlier values of figures of merit should be carefully analyzed; the computational time is a key element to perform UQ in SA; the large number of uncertain input parameters may complicate the interpretation of correlation or sensitivity analysis; there is the need for a statistically solid handling of failed calculations.

Improved collision handling of elastic solids in sph using a contact force model

Improved collision handling of elastic solids in sph using a contact force model

People’s Perception and the Current Policy Gap for Solid Waste Handling in Delhi

MSW management directly impacts public health and quality of life in cities. Unfortunately, solid waste management is generally considered the exclusive domain of government. However, since residents are the primary generators of municipal solid waste, there is virtually worldwide consensus among all major stakeholders that citizens must actively participate in this process. The need for more awareness among citizens and better communication between the government and citizens severely hampers this. Therefore, specific government initiatives are needed to bridge this communication gap. With this in mind, this study presents a structure for developing a waste management transmission process that recognises the public’s leading issues and the best strategies for raising public awareness. The results indicate that people’s attitudes toward solid waste could be more satisfactory. The government should also involve the public in managing regional and local waste problems.

Mercury in the Barents region – River fluxes, sources, and environmental concentrations

Arctic rivers are receiving increased attention for their contributing of mercury (Hg) to the Arctic Ocean. Despite this, the knowledge on both the terrestrial release sources and the levels of Hg in the rivers are limited. Within the Arctic, the Barents region has a high industrial development, including multiple potential Hg release sources. This study presents the first overview of potential Hg release sources on Norwegian and Russian mainland draining to the Barents Sea. Source categories cover mining and metallurgy industry; historical pulp and paper production; municipal and industrial solid waste handling; fossil fuel combustion; and past military activities. Available data on Hg in freshwater bodies near the identified potential release sources are reviewed. Levels of Hg were occasionally exceeding the national pollution control limits, thereby posing concern to the local human population and wildlife. However, the studies were sparse and often unsystematic. Finally, we present new data of Hg measured in five Barents rivers. These data reveal strong seasonality in the Hg levels, with a total annual flux constituting 2% of the panarctic total. With this new insight we aspire to contribute to the international efforts of reducing Hg pollution, such as through the effective implementation of the Minamata Convention. Future studies documenting Hg in exposed Barents freshwater bodies are warranted.

RFID and IoT Enabled Framework to Make Pune City an Eco-friendly Smart City

The increasing volume and complexity of waste associated with the modern economy pose a serious risk to ecosystems and human health. Due to the intensive increase in computation, Machine learning is popular. Intelligent solid waste management motivates the Swachh Bharat mission to celebrate the 150th anniversary of the birth of astrapita Mahatma Gandhi. In the context of smart city development, an innovative means of implementing smart solid waste collection is to improve daily solid waste collection at the household level. An intelligent solid waste collection system will be implemented in the Smart City to improve solid waste collection. It is required to educate households about solid waste handling. Municipal Corporation can implement an innovative PPP model as part of an independent India campaign to motivate startup ntrepreneurs, which will generate jobs in India. The city of Pune is in a phase of intelligent urban mobility development to improve citizens’ living standards. Ensure safe traffic management, adequate water supply, smart amenities, and services such as the intelligent collection, transport, and processing of solid waste. RFID and IoT base IT solutions have the potential to develop sustainable, innovative technology to achieve 100% household collections and transportation and treatment of waste so that to minimize waste to send landfill side.

Effect of Moisture Content on Frictional Properties of Some Selected Grains in Indonesia

The frictional property of grains is one of the most important engineering parameters in developing solid bulk handling of grains. It is necessary for designing agricultural facilities and production process activities. These properties are expressed as internal friction angle (φ) and wall friction angle (θ), which are known to be affected by the moisture content of the grains. This research investigates the effect of moisture content on the values of φ and θ of some selected grains. In the research, some indigenous Indonesian grain types, including rough rice, white rice, corn, soybean, and coffee, each in three varieties and three level of moisture contents, were used as the research samples. Those angles were measured using a self-constructed direct shear cell apparatus. Three different normal loads for each grain type were used with three replications. It is concluded that φ and θ of the tested grains increase with moisture contents with different trends of increments. The relationship of those angles with moisture contents can be expressed as linear regression equations. The slope of the regression lines for both φ and θ is significantly affected by grain type (p&lt;0.05). For φ, coffee (Excelsa) is the most susceptible to the change in moisture content, while dent corn (Hibrida) is the least affected one. For θ, soybean (Galunggung) is the most susceptible to the change in moisture content, while rough rice (Mapan 5) is the least affected one.

On-Site Solid Waste Handling Practice and Associated Factors among Condominium Residents in Gondar City, Northwest Ethiopia, 2021: A Community-Based Cross-Sectional Study.

Solid waste is one type of waste that is released from human day-to-day activities and it is considered useless or unwanted for further use. Population growth, rapid urbanization, a booming economy, and an increase in the standards of living of the community have substantially enhanced the rate of solid waste generation in developing countries. Solid wastes can be used as a resource for industrial production or energy generation. However, it causes environmental and human health problems due to poor management. There is scanty information about on-site solid waste management practice in the study area. Therefore, assessing on-site solid management practices and their associated factors, especially for condominium residents is very important. To assess on-site solid waste handling practice and its associated factors among condominium residents in Gondar city, northwest Ethiopia, 2021. A community-based cross-sectional study was conducted from March 1 to June 15/2021 among condominium residents in Gondar city. The study included a total of 450 condominium households, with a 99.3% response rate. A binary logistic regression model was used to assess the association between dependent and independent variables. Those variables which have a p value <0.25 in the bivariate analysis were entered into a multivariable logistic regression model. A p value of less than 0.05 with 95% CI was considered a statistically significant factor. In this study, 79.8% with 95% CI (76.4%, 83.3%) of condominium residents had poor on-site solid waste handling practices. The finding also showed that 42.2% and 50.2% of study participants have favorable attitudes and good knowledge towards on-site solid waste handling practices, respectively. In multivariable logistic regression analysis, male household heads (AOR = 1.90; 95% CI, 1.11-3.28), large family size (AOR = 1.87; 95% CI, 1.03-3.40), negative attitude towards on-site solid waste handling practices (AOR = 1.79; 95% CI, 1.07-3.00), not receiving training (AOR = 3.40; 95% CI, 1.77-6.55), and not having legal enforcement (AOR = 2.85; 95% CI, 1.39-5.84) were significantly associated with on-site solid waste handling practices. The on-site solid waste handling practice of condominium households was very poor. The provision of training and enforcement of rules regarding solid waste handling is necessary.

Review: The Calibration of DEM Parameters for the Bulk Modelling of Cohesive Materials

Granular materials are abundant in nature, and in most industries, either the initial constituents or final products are in granular form during a production or processing stage. Industrial processes and equipment for the handling of bulk solids can only be improved if we can understand, model and predict the material behaviour. The discrete element method (DEM) is a numerical tool well-suited for this purpose and has been used by researchers and engineers to analyse various industrial applications and processes. However, before any bulk scale modelling can be undertaken, the input parameters must be carefully calibrated to obtain accurate results. The calibration of parameter values for non-cohesive materials has reached a level of maturity; however, the calibration of cohesive materials requires more research. This paper details the most prevalent contact models used to model cohesive materials—presented in a consistent notation. Moreover, the significant differences between the models are highlighted to provide a reference for engineers and researchers to select the most appropriate model for a specific application. Finally, a critical review of calibration experiments and methodologies often used for cohesive materials is also presented. This provides a solid basis for DEM practitioners to select the most appropriate calibration methodology for their application and for researchers to extend the current state-of-the-art practices.

Work-Life Challenges Faced by Sanitary Workers-A Special Reference to Thoothukudi District

Waste production occurs due to business activities, consumption, and use of goods or materials. Solid waste handling, management, and precise and appropriate disposal is a hot topic and public and environmental health concern topic. Sanitary workers are primarily responsible for the health of the entire world. At the same time, challenges such as issues related them financial, mental, and physical problems. Injuries include cuts, bruises, musculoskeletal issues, respiratory issues, gastroenteritis, diarrhea, hepatitis A, hepatitis B, and typhoid fever. Furthermore, they are facing a lack of financial security, and they are facing various social problems. This study selects the primary and secondary data. The primary data were directly collected from the respondents, and it had been preparing a structured questionnaire. Secondary data it had been collected from the website, published journals, and magazines. This has been chosen as the stratified sampling method. It has selected 120 respondents and describes the health problems faced by sanitary workers at work in Thoothukudi District. Public health research has not adequately considered the welfare and conservation of sanitary workers. Unlike other risk industries, sanitation does not have specific safety regulatory guidelines for resolving health risks.

Dynamic study on particle throwing motion of pulsating negative pressure shale shaker

This research is based on a new drilling fluids circulation treatment device, which belongs to solid control system, namely pulsating negative pressure shale shaker. The purpose of this article is to better understand the operating principle and provide basis for setting working parameters and optimizing design. The above content depends on the dynamic analysis of the throwing motion of particles. To be specific, the motion equation of particle is established from the viewpoint of force state, and the influence of various parameters on particle conveyance velocity is discussed. Factors influencing the throwing index are also analyzed. Higher solid conveyance speed means higher handling capacity, but it also reduces the efficiency of particle dehydration; therefore, a trade-off should be considered among high removal efficiency, low energy consumption, and high handling capacity. The results show that negative pressure in pulsating form can effectively improve the disadvantage of low conveyance velocity of particles in constant negative pressure shale shaker.

Municipal solid waste, an overlooked route of transmission for the severe acute respiratory syndrome coronavirus 2: a review.

Municipal solid waste could potentially transmit human pathogens during the collection, transport, handling, and disposal of waste. Workers and residents living in the vicinity of municipal solid waste collection or disposal sites are particularly susceptible, especially unprotected workers and waste pickers. Recent evidence suggests that municipal solid waste-mediated transmission can spread the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to humans. Such risks, however, have received little attention from public health authorities so far and may present an under-investigated transmission route for SARS-CoV-2 and other infectious agents during pandemics. In this review, we provide a retrospective analysis of the challenges, practices, and policies on municipal solid waste management during the current pandemic, and scrutinize the recent case reports on the municipal solid waste-mediated transmission of the coronavirus disease 2019 (COVID-19). We found abrupt changes in quantity and composition of municipal solid wastes during the COVID-19. We detail pathways of exposure to SARS-CoV-2 and other pathogens carried on municipal solid wastes. We disclose evidence of pathogenic transmission by municipal solid waste to humans and animals. Assessments of current policies, gaps, and voluntary actions taken on municipal solid waste handling and disposal in the current pandemic are presented. We propose risk mitigation strategies and research priorities to alleviate the risk for humans and vectors exposed to municipal solid wastes.

Understanding Powder Behavior in an Additive Manufacturing Process Using DEM

The handling of bulk solids in the form of powders is a fundamental process in a wide range of manufacturing industries, such as the automotive, aerospace, food, and healthcare sectors. All these sectors employ additive manufacturing (AM), as it enables the production of complex parts in a short amount of time. Thus, it is considered an established method for developing an agile manufacturing environment that can drastically reduce the lead time from conception to the production stage. At the same time, powder is a unique material sensitive to environmental and machine conditions; hence, establishing an optimal configuration is not straight-forward. This work presents a discrete element method (DEM) simulation of an experimental dosing system used in AM. We introduce a robust workflow that correlates suitable experimental data with simulation results, establishing models of real powders with different flowability. The results showed an excellent agreement between the experimental data and the simulation results and provided a better understanding of the material behavior. Furthermore, we employed a coarse-grained approach to extract continuum fields from the discrete data. The results showed that the cohesion level in the system was enough to create agglomerates that hindered the transport of the material and produced nonuniform distribution.

Waste Reduction Strategy in Upstream Through Community Participation and Modernisation of Waste Bank in Depok City, West Java Province, Indonesia

Depok city with more than 2 million people is an example of a city in a developing country facing complex urban problems. Solid waste handling is one of the critical issues in the city. More than 1,500 tons of waste are generated every day, and currently, the leading landfill site receives approximately 70% of the waste in the city. The purpose of this paper is to present a comprehensive waste management strategy for waste reduction in Depok City through community participation and modernisation of the local waste bank. The study combined qualitative data collection; interviews and direct observation in the two (2) waste bank, quantitative survey (Multinomial Logistic Regression method) with 319 waste bank managers, and 423 respondents from 11 sub-districts in Depok City. Infrastructures and socialisation are the two (2) variables that affect significantly towards modernisation of the waste bank. Meanwhile, in the context of community participation, only 36% of the respondents process their own household waste. Studies on the waste management subject are extensive, but this paper only discusses two (2) elements; community participation and modernisation of the waste bank. Extending more relevant elements of waste management will have contributed to the sustainability of the environment. This research complements references from previous studies that discuss sustainable waste management. It is hoped that the sustainable waste management strategy in Depok City can be an excellent example for other cities in other developing countries.