Waste Management & Research: The Journal for a Sustainable Circular Economy

The treatment and disposal of industrial waste has become a critical economic and environmental issue with the ever-increasing rates of its generation. Industries in India, as major players in building the economy and GDP, expel about 7.4 million tons of hazardous waste annually, out of which around 3.98 million tons are recyclable for resource or energy recovery. India’s scenario in the usage of alternative fuel and raw material is less than 1%, which reflects a huge quantum of hazardous waste for potential usage in alternative fuel and raw material. The Netherlands, with around 83% of total hazardous waste, is the highest user of hazardous waste as alternative fuel and raw material in cement kilns. Uncontrolled waste management degrades land, ground water and air quality, leading to health risks to humans, animals and the ecosystem. Presently, industrial waste in most cases is disposed to landfills after incineration, without utilizing the full potential of the wastes through recirculation. The present study analyzed the current situation of the treatment facilities for attaining a sustainable management system using waste as alternative fuel and raw material for the disposal of hazardous waste. Through the alternative fuel and raw material concept, hazardous wastes can be used as a substitute for fossil fuels and/or raw material in a few types of industries. This will surely enhance the efficient recirculation of industrial wastes. This paper presents the overall view of Indian hazardous-waste generating industries, their locations, the potential of wastes as alternate sources of fuel to other industries, the use of alternative fuel and raw material by cement industries and applicable regulatory requirements.

This study aims to present waste characterisation, solid waste management practice and analyse the challenges in the solid waste management system in the tourism destination of Hoi An City, Vietnam. The sampling and questionnaire surveys were conducted for measuring characterisation and management practice of solid waste. A material flow analysis method was used for analysing the waste flow. The results show that the tourism destination generated daily around 15080 kg t of waste, in which the significant proportions come from restaurants (46%), hotels (22%) and households (13%). The feature of the waste composition is high rates of kitchen waste (46.8%), tissue (11.54%) and recyclable materials (12.58%), which result in high moisture (46.79%) and a low heating value (16,866 kJ kg^-1) of waste. Also, solid waste management practices were evasively implemented by stakeholders with low rates and efficiency. Furthermore, a substantial gap of the solid waste management system is the confusion in waste collection activities, which is shown by the overload of waste in street bins and the financial loss for the solid waste management system owing to the non-compliance with collection regulation of stakeholders. Also, the mixing of waste by collection crews after separation at sources, the in-appropriation of collection time and manner are the dark points of the solid waste management system that may be causes of the non-cooperation of stakeholders. These gaps and confusion in the solid waste management system are the significant challenges in the improvement of the solid waste management system in the tourism destination toward sustainability.

Urban waste collection is one of the principal processes in municipalities with large expenses and laborious operations. Among the important issues raised in this regard, the lack of awareness of the exact amount of generated waste makes difficulties in the processes of collection, transportation and disposal. To this end, investigating the waste collection issue under uncertainty can play a key role in the decision-making process of managers. This paper addresses a novel robust bi-objective multi-trip periodic capacitated arc routing problem under demand uncertainty to treat the urban waste collection problem. The objectives are to minimize the total cost (i.e. traversing and vehicles’ usage costs) and minimize the longest tour distance of vehicles (makespan). To validate the proposed bi-objective robust model, the ε-constraint method is implemented using the CPLEX solver of GAMS software. Furthermore, a multi-objective invasive weed optimization algorithm is then developed to solve the problem in real-world sizes. The parameters of the multi-objective invasive weed optimization are tuned optimally using the Taguchi design method to enhance its performance. The computational results conducted on different test problems demonstrate that the proposed algorithm can generate high-quality solutions considering three indexes of mean of ideal distance, number of solutions and central processing unit time. It is proved that the ε-constraint method and multi-objective invasive weed optimization can efficiently solve the small- and large-sized problems, respectively. Finally, a sensitivity analysis is performed on one of the main parameters of the problem to study the behavior of the objective functions and provide the optimal policy.

A waste analysis and characterisation study requires urgent measures to regulate and to solve the piling up of garbage worldwide; this is an essential factor towards the projection of a feasible and environmentally acceptable solution. Baguio City is a favourite holiday destination during summer in the Philippines; initially designed as a hill station for 25,000 people, its population has now risen to 345,400, which doubles and even triples during peak seasons. As such, this study was conducted to determine the levels of waste generation and assess the current diversion method of its municipal solid waste to prevent the town from further deteriorating into unsustainable urbanisation. The results revealed that the total waste generated is 402,776.38 kg per day, wherein the average per capita waste generation for domestic sources is 0.4193 kg per day. Solid waste is composed of biodegradables (41.67%), recyclables (33.78%), residuals (24.15%) and special wastes (0.40%), with the average moisture level of the solid waste sample at 57.462%. With tourists contributing 19.69% of those wastes during peak events, the only recoverable wastes were biodegradables and recyclables, which have a diversion percentage of 23.28%. The study recommends to the city of Baguio to have its own engineered sanitary landfill, simulated GIS-based collection system and expanded waste recovery facility, to increase waste-diversion percentages and to decrease its expenditure for hauling, collecting, storing and transporting its solid waste, in order to adhere to its mission of creating a sustainable and enabling environment.

Cyanide is among the most toxic chemicals widely employed in the cyanidation process to leach precious minerals, such as gold and silver, by the minerals processing companies worldwide. This present article reviews the determination and detoxification of cyanide found in gold mine tailings. Most of the cyanide remains in the solution or the slurries after the cyanidation process. The cyanide species in the gold tailings are classified as free cyanide, weak acid dissociation, and metallocyanide complexes. Several methods, such as colorimetric, titrimetric, and electrochemical, have been developed to determine cyanide concentrations in gold mine effluents. Application of physical, natural, biological, and chemical methods to detoxify cyanide to a permissible limit (50 mg L⁻¹) can be achieved when the chemical compositions of cyanide (type of species) present in the tailings are known. The levels of cyanide concentration determine the impact it will have on the environment.

Industrial solid waste management encompasses a vital part of developed and developing countries strategies alike. It manages waste generated from vital industries and governs the hazardous waste generated as a major component of integrated waste management strategies. This article reviews the practices that govern the management approaches utilized in the developed world for industrial spent catalysts. It critically assesses the current situation of waste management within the developing world region focusing on the industrial waste component, in a novel attempt to crucially develop a strategy for a way forward based on best practices and future directions with major European industries. The review also draws parallels with European countries to compare their practices with those of the State of Kuwait, which rely solely on landfilling for the management of its industrial waste. Spent catalysts recovery methods are discussed at length covering conventional methods of valuable metals and chemicals recovery (e.g., hydrometallurgical, solid–liquid and liquid–liquid extraction) as well as biological recovery methods. A major gap exists within regulations that govern the practice of managing industrial waste in Kuwait, where it is essential to start regulating industries that generate spent catalysts in-view of encouraging the establishment of valorization industries for metal and chemical recovery. This will also create a sustainable practice within state borders, and can reduce the environmental impact of landfilling such waste in Kuwait.

Heavy metals such as Co, Li, Mn, Ni, etc. and organic compounds enrich spent lithium-ion batteries (LIBs). These batteries seriously threaten human health and the environment. Meanwhile, with the development of new energy vehicles, the shortage of valuable metal resources which are used as raw materials for power batteries is becoming a serious problem. Using proper methods to recycle spent LIBs can both save resources and protect the environment. Pyrometallury is a kind of recycling method that is operated under high temperature with the aim of recovering useful metals after pre-treatment and organic binder removal with the characteristic of high temperature and it is easy to operate. Hydrometallurgy is characterized by high recovery efficiency, low reaction energy consumption, and high reaction rate, and is widely used in the recycling process of spent LIBs. During biometallurgy, valuable metals in the spent LIBs are extracted by microbial metabolism or microbial acid production processes. Since the drive for green and low secondary pollution, biometallurgy as well as solvent extraction and the electrochemical method have earned more attention during recent years. This mini-review analyzes the relationship between the emergence of new energy vehicles and the recycling status of spent LIBs. Meanwhile, this paper also consists of detailed treatment and recycling methods for LIBs and provides a summary of the management regulations of current waste for LIBs. What is more, the main challenges and further prospects in terms of LIBs management in China are analyzed.

In order to activate the recycling of hazardous wastes, the hazardous characteristics of wastes should be removed or stabilized. However, most recyclers in recycling companies do not understand how to remove the hazardous characteristics in wastes with the proper technology. The aim of a new form of advanced management of hazardous waste is to inform recyclers and operators in industries about hazardous characteristics and the treatment methods required for all management processes, from waste generation to final treatment. In a new method of advanced management of hazardous wastes, chemicals in the waste should be initially examined at the generation source in each industry to create a chemical catalogue. Since hazardous characteristics can be determined by a chemical catalogue obtained from the waste, the hazardous characteristics of wastes can be established and considered when choosing the proper treatment method. Then, the categories of waste treatment methods for each hazardous characteristic can be introduced for generators to treat hazardous wastes properly. Therefore, it is possible to create a link between the source and the final treatment of hazardous wastes using a new concept of industry (In), waste (W), hazardous chemicals and their hazardous characteristics (Ha) and treatment methods (T). This new concept of the “InWhat” system, which includes all management processes in Korea, from waste generation to final treatment, will be proposed as a tool in the advanced management of hazardous wastes.

With the growth of urbanization in countries globally, large cities have often formed clusters of urban agglomerations in metropolitan areas. The coordinated management of regional solid waste produced by such urban agglomeration poses a typical high-dimensional, multi-objective optimization issue. This paper aims to introduce a procedure to implement the third-generation genetic algorithm (NSGA-III), an established multi-objective genetic algorithm based on non-dominated sorting mechanisms, for the purpose of evaluating environmental and economic benefits simultaneously while seeking the optimal solutions for coordinated management among multiple recycling centres. In this study, two series of scenarios were abstracted from scrap tire recycling, representing linear calculation and nonlinear calculation cases separately. Several improvements were made to the originally published NSGA-III procedure that solve the problem of non-convergence for hypervolumes of the output. Through comparisons of calculation results, an improved procedure is suggested and shown to have improved performance.

Cathode ray tube televisions (TVs) contributes significantly to the rapidly increasing waste stream of cathode ray tubes in the e-waste. This study mainly focused on the material flow of waste cathode ray tube TVs in China. Currently, waste cathode ray tubes constitute a major part of the total generation of e-waste in China. The study aimed to emphasise the flow of materials in the generated waste cathode ray tube TVs by using stock-based material flow analysis model. The modelling was conducted to investigate the disposable number of obsolete devices, in-use stock, and end-of-life of cathode ray tube TVs. SubSTance flow ANalysis (STAN) software was used to perform the material flow analysis modelling and graphical model of the waste cathode ray tube TVs. The results show that in a period of 10 years, overall about 3241.37 kt of cathode ray tube TVs were net produced in China, containing 183.6 kt of glass, 1718.2 kt of plastic, 243 kt of steel/iron, 153.5 kt of lead, 76.6 kt of copper, 7.8 kt of aluminium, and 1.6 kt of antimony. The results revealed that almost 125 kt of end-of-life cathode ray tube TVs containing about 68 kt of glass, 40 kt of plastic, 9 kt of steel/iron, 6 kt of lead, 3 kt of copper, 0.3 kt of aluminium, and 0.07 kt of antimony were dumped in the period of 10 years. Therefore, the management of waste cathode ray tube TVs required better infrastructure for recycling and better regulation to achieve better results in the high recovery of valuable resources.