Study on Medical Waste Collection and Routing Problem

It is observed that the separated design of location for depots and routing for servicing customers often reach a suboptimal solution. So, solving location and routing problem simultaneously could achieve better results. In this paper, waste collection problem is considered with regard to economic and societal objective functions. A non-dominated sorting genetic algorithm (NSGA-II) is used to locate depots and treatment facilities and design the routes starting from depots to serve customers. A new mathematical model is proposed and two objective functions including economic objective (opening cost of depots and treatment facility and transportation cost) and societal objective; that is, negative impact of treatment facilities which are close to towns are addressed in this study. A straightforward order based solution representation is applied for coding solutions of the problem and clustering approach is used to generate appropriate initial solutions. Moreover, three multi-objective decomposition methods including weighted sum, goal programming, and goal attainment are applied to validate the performance of the proposed algorithm. Number of test problems are conducted and the results obtained by algorithms are compared with respect to some comparison metrics. Finally, the experimental results show that the proposed hybrid NSGA-II outperforms all decomposition methods, but the computational times for decomposition methods are less than NSGA-II.

Capacitated arc routing problem (CARP) is the youngest generation of graph theory that focuses on solving the edge/arc routing for optimality. Since many years, operational research devoted to CARP counterpart, known as vehicle routing problem (VRP), which does not fit to several real cases such like waste collection problem and road maintenance. In this paper, we highlighted several extensions of capacitated arc routing problem (CARP) that represents the real-life problem of vehicle operation in waste collection. By purpose, CARP is designed to find a set of routes for vehicles that satisfies all pre-setting constraints in such that all vehicles must start and end at a depot, service a set of demands on edges (or arcs) exactly once without exceeding the capacity, thus the total fleet cost is minimized. We also addressed the differentiation between CARP and VRP in waste collection. Several issues have been discussed including stochastic demands and time window problems in order to show the complexity and importance of CARP in the related industry. A mathematical model of CARP and its new version is presented by considering several factors such like delivery cost, lateness penalty and delivery time.

A large amount of medical waste is produced during disaster relief, posing a potential hazard to the habitat and the environment. A comprehensive understanding of the composition and characteristics of medical waste that requires management is one of the most basic steps in the development of a plan for medical waste management. Unfortunately, limited reliable information is available in the open literature on the characteristics of the medical waste that is generated at disaster relief sites. This paper discusses the analysis of the composition and characteristics of medical waste at a disaster relief site using the retrospection-simulation-revision method. For this study, we obtained 35 medical relief records of the Wenchuan Earthquake, Sichuan, May 2008 from a field cabin hospital. We first present a retrospective analysis of the relief medical records, and then, we simulate the medical waste generated in the affected areas. We ultimately determine the composition and characteristics of medical waste in the affected areas using untreated medical waste to revise the composition of the simulated medical waste. The results from 35 cases showed that the medical waste generated from disaster relief consists of the following: plastic (43.2%), biomass (26.3%), synthetic fiber (15.3%), rubber (6.6%), liquid (6.6%), inorganic salts (0.3%) and metals (1.7%). The bulk density of medical relief waste is 249 kg/m3, and the moisture content is 44.75%. The data should be provided to assist the collection, segregation, storage, transportation, disposal and contamination control of medical waste in affected areas. In this paper, we wish to introduce this research method of restoring the medical waste generated in disaster relief to readers and researchers. In addition, we hope more disaster relief agencies will become aware of the significance of medical case recording and storing. This may be very important for the environmental evaluation of medical waste in disaster areas, as well as for medical waste management and disposal.

Purpose: The aim of the article is to analyze problems related to the logistics of medical waste in the Silesian Municipal Hospital. The research issues focused on the analysis of currently used solutions, the causes of existing problems and proposals for improvements aimed at improving the quality of medical waste management processes in the hospital. The research will focus on analyzing areas related to the collection, storage, transport, and disposal of medical waste. Design/methodology/approach: In the research presented in this article, an analysis of the literature on the processes of the waste management was used. The research focused on analyzing areas related to the collection, storage, transport, and disposal of medical waste. The analysis covered also procedures related to the segregation of medical waste and compliance with applicable regulations. The research focused also on assessing the effectiveness of existing logistics processes in waste management and identifying potential areas requiring improvement. IGrafx program was used for research and modeling. Findings: The research showed some problems related to human resources, waste storage, transportation of medical waste and disinfection of carts and storages. Therefore, carrying out this assessment and analysis of the medical waste logistics management system allowed to propose corrective actions and improvements in the areas that most require improvement and adversely affect the waste logistics process. Research limitations: The research limitation was an access to some data in the hospital. In the future similar research should be carried out in another hospitals in Silesia region. Practical implications: Carrying out this assessment and analysis of the medical waste logistics management system allowed to propose corrective actions and improvements in the areas that most require improvement and adversely affect the waste logistics process. The introduction of the proposed improvements will increase the efficiency of the process and contribute to minimizing the risk of current problems occurring in the future. Originality/value: The article shows the scale of the problem that can occur in many hospitals in Poland. Additionally, the article presents some recommendations for hospital staff, which aimed at minimizing the health risk to patients and staff, as well as improving compliance with standards and procedures set in the hospital.

This study estimates the Medical Waste (MW) generated and the handling process in six Healthcare Facilities (HF) in Ghana, Sub-Saharan Africa (SSA), and identifies the associated parameters. The data were collected by field work and MW collection, identification and weighing. The results indicate that the average rate of infectious MW ranged from 0.23 to 2.34 kg/bed/day (M = 0.95 kg/bed/day), and 0.24 to 1.68 kg/bed/day for non-infectious MW (M = 0.56 kg/bed/day). An amount of 11.41 tonnes of MW were estimated in the six HF in Greater Accra and Eastern Region in Ghana, comprising 49.1% infectious MW. The results suggest that the number of outpatients/day and the size of HF are the main predictors for the MW generation. The study shows that the segregation of MW is not correctly practised in the studied HF since 33% used the uncontrolled combustion process of open burning and dumping to handle 0.99 tonnes (8.7%) of MW.

Increasing urbanization and rising consumption rates are putting pressure on urban systems to efficiently manage Municipal Solid Waste (MSW). Waste collection, in particular, is one of the most challenging aspects of MSW management. Therefore, developing computer-aided tools to support decision-makers is crucial. In this paper, a Scatter Search algorithm is proposed to address the waste collection problem. The literature is relatively scarce in applying this algorithm, which has proven to be efficient in other routing problems, to real waste management problems. Results from real-world instances of an Argentine city demonstrate that the algorithm is competitive, obtaining, in the case of small instances, the same outcomes as those of an exact solver enhanced by valid inequalities, although requiring more computational time (as expected), and significantly improving the results of the latter for the case of larger instances, now requiring much less computational time. Thus, Scatter Search proves to be a competitive algorithm for addressing waste collection problems.

The Solutions and Recommendations for Logistics Problems in the Collection of Medical Waste in China

Background: Metal exposure during medical waste collection, handling, and burning poses a skin danger to individuals working in the waste incineration industry. Medical waste incineration ash contains about 30 distinct metals, the majority of which are toxic to humans. This study attempts for improving the health of workers at medical waste incinerators through identifying some occupational morbidities among workers at medical waste incinerators. Methods: A comparative cross-sectional study was conducted at medical waste incinerators at Sharkia governorate. The target population composed of exposed group (n=56), including workers at medical waste incinerators who are involved in all steps of handling, management and processing of medical waste and non-exposed group (n=56), including administrative employees working at Faculty of Medicine, Zagazig University. Pre-constructed questionnaire was filled by all participants for their occupational history and dermatological presentations.Results: A statistically significant increase in frequency of burn (OR=5.34), urticaria (OR=7), exposure to sharp injuries (OR=85), pruritis and fatigue among exposed compared to non-exposed group. Also, a statistically significant increase in dermatological morbidities were found among workers who had previous job & not wearing protective personal equipment (PPE) compared to workers without (p=0.01).Conclusion: It can be concluded from the results of the study that incinerator workers at Sharkia governorate are at risk for dermatological disorders and sharp injuries who pose them to risk of Hepatitis B (HBV) and Hepatitis C (HCV) infection.

In this paper we consider the collection of infectious medical waste, produced by patients in self-treatment and stored at pharmacies. The problem is formulated as a collector-managed inventory routing problem, encompassing stochastic aspects, which are common in such problems. Social objectives, specifically the satisfaction of pharmacists and the local authority, as well as the minimization of public health risks, are considered for the real-world motivated inventory routing problem. To optimize the planning process for a predefined time horizon, we take advantage of radio frequency identification technologies. We design a tabu search based algorithm to optimize the determination of visit dates and corresponding vehicle routes. The suggested approach is tested on real-world data from the region of Provence-Alpes-Côte d’Azur, in France. The results for different waste collection scenarios are analyzed and compared in order to evaluate the performance of the proposed solution method.

This study aimed to evaluate the policy of solid medical waste management at RSIA Yasmin Palangka Raya. The main issues faced include discrepancies in packaging, collection, storage, and transportation of medical waste. A qualitative descriptive approach was employed using purposive sampling method to collect data through interviews, observations, and document analysis. The research findings revealed that despite the existence of internal policies, there were inconsistencies with the applicable regulations, particularly in waste packaging, segregation, and transportation. The composition of solid medical waste generated included infectious waste, non-sharp infectious waste, and sharp infectious waste. Policy recommendations are suggested to improve waste segregation, staff training, increase transportation frequency, and upgrade storage facilities. By implementing these recommendations, RSIA Yasmin Palangka Raya can enhance the effectiveness of solid medical waste management in accordance with regulations.

Medical waste management in Ibadan, Nigeria: Obstacles and prospects

Modern cities produce larger amounts of waste causing profound negative impacts on our natural environment. For this reason, processes related to waste collection, transportation, transformation and final disposal have increased their importance and major adequacy is desirable. Several Waste Management (WM) problems have to be solved in order to obtain efficient related services. Traditional Vehicle Routing Problem and Waste Collection Problem solution approaches presented in the literature are not suitable to face problems related to specific topology of the city, districts, street dimension and shape of the clusters. In this paper we propose a pre-process cluster solution in order to take into account different information such as street names, street dimension and civic number in order to create cluster more acceptable by the final users. In order to show the effectiveness of the proposed methodology, we compare hierarchical and spectral clustering-based algorithms. Finally, we apply our proposal in a real case study based on a data set extracted from a city in the north-east of Italy.

A Waste Collection Arc Vehicle Routing Problem with turn constraints (WCAVRPTC) model is proposed to minimize the length of municipal solid waste (MSW) collection routes, which presents several characteristics derived from traffic regulations: some streets can be traversed crossed in only one direction, and some turns should be forbidden when the common angle is too narrow. The problem is transformed into a node routing ones and a clustering-based multiple ant colony system algorithm is described to address it. This algorithm possesses a set of new strategies to construct solutions, including clustering-based strategy, improved global pheromone update rule. The methodology is also applied to the urban waste collection problem in Shuangnan. The results of optimization indicate that the length of saving routes is 89984.96m and 92330.04m respectively with or without turns constrains constraints, which decreased by 31.1% and 31.9% respectively.

In this paper, we consider the waste collection problem from customers’ location with assumptions that are closer to real life applications of the problem. The fleet of vehicles is heterogeneous and vehicles have separated compartments, namely they have different capacity for each type of waste. Also, the vehicles have different traveling time limitation and different variable and fixed cost according to their types. As well as, the multi-depot vehicle routing problem and the mixed close-open vehicle routing problem are combined together. The objective of the problem is minimizing the cost of servicing to customers with respect to customers’ demands and available constraints. A new mathematical MIP model is proposed and to deal with this problem, three meta-heuristic algorithms are investigated and the results are compared with the results of CPLEX solver. The results of experiments show that the proposed Meta-heuristic algorithms are able to produce satisfied solutions with regard to the MIP solver CPLEX.

This article deals with a real‐life waste collection routing problem. To efficiently plan waste collection, large municipalities may be partitioned into convenient sectors and only then can routing problems be solved in each sector. Three diverse situations are described, resulting in three different new models. In the first situation, there is a single point of waste disposal from where the vehicles depart and to where they return. The vehicle fleet comprises three types of collection vehicles. In the second, the garage does not match any of the points of disposal. The vehicle is unique and the points of disposal (landfills or transfer stations) may have limitations in terms of the number of visits per day. In the third situation, disposal points are multiple (they do not coincide with the garage), they are limited in the number of visits, and the fleet is composed of two types of vehicles. Computational results based not only on instances adapted from the literature but also on real cases are presented and analyzed. In particular, the results also show the effectiveness of combining sectorization and routing to solve waste collection problems. © 2015 Wiley Periodicals, Inc. NETWORKS, Vol. 65(2), 155–165 2015