There is a variety of software classes specialized for various fields and different types of waste management such as hazardous waste management. A typical example is the software group called ESS (see later). The features of general waste management software, however, focus mainly on
• Proving compliances
• Reports, standard and customized forms to create reports
o Manifest, profiling, quotes, invoicing, inventory tracking, sales, company etc.
o Integrate external database reports o Ad hoc reports
• Shipment returns
• Sales and pricing: create standard price lists o Establish profile based pricing
o Pricing based on multiple units of measure o Cost optimisation
• Invoicing, including sales orders, automatically scheduled sales orders, and sales tax calculations.
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This is nothing else but treating waste management as a service and considering business interests only. The reason is that waste management software tools are frequently developed for waste haulers.
This group of software differentiates the primary focuses of main waste business categories, including commercial, residential, industrial/roll-off, landfill, transfer station, solid waste, liquid waste, medical waste, hazardous waste, and environmental service companies.
Some programs have additional features related to the process or system approach, e.g.
waste tracking, routing, and waste characterization for accuracy and consistency.
The above classification is based on thorough software assessment as part of the PhD research. It will be described later in more detail.
2.3.1 Waste management software tools and modules
There are many comprehensive features of waste management software supporting the operation of waste management systems, including, but not limited to
• Waste profiling: create and manage profiles to control processes o Characterize hazardous and non-hazardous materials
o Maintain physical characterization and chemical composition o Control certifications
• Waste manifesting: simplify compliance and paperwork creation o Establish proper manifest identification
o Establish generator and multiple transporters o Maintain waste codes
o Edit or view container information o Special handling information
• Administering: highly configurable systems to fit the administration requirements of internal processes
o System preferences o Customization o User maintenance o Data dictionary
• Reports: create reports that meet governmental criteria and industrial standards
• Material processing: maintain a permanent record of movement and processing all of the inventoried items
o Transaction logging of material processes o Repack
o Move drums o Decant
• Receiving and shipping: handle input and output waste information o Handle differences of processed waste volumes
o Establish materials received into inventory, as well as the ones received as individual items
o Establish weight and volume for materials in inventory o Shipment outputs
• Invoicing: create invoices on items listed above
• Sales and pricing: economic considerations
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• Scheduling: control schedules of input and output shipments and help to create paperwork for drivers
o Scheduling multiple pick-ups for various loads o Truck and driver information
o Quick search for loads
• Work orders: control projects and time tracking o Issue tracking
o Workflow control
• Laboratory analysis: manage laboratory packages o Laboratory package templates o Tracking associated waste codes
o Tracking associated chemical properties
• Audit: management of track and audit changes
• Optional features: barcoding, approvals etc.
The most comprehensive features were identified and highlighted as part of the PhD research. There are commercial software tools that combine some of these options as cooperating modules in order to offer a comprehensive set of tools for waste management operators and provide a central management.
On the other hand, the majority of them are rather specific. The most widely used WWTP simulators (GPS-X, AQUASIM, DESASS, EFOR, SIMBA), for example, include a biological model and additional simulator models for settling units, fixed film operations, dissolved oxygen control. Even if these modules can be very effective themselves, the overall modelling performance can be improved through additional features. The main limitation of waste management software in general is that availability and reliability issues are not considered in the adequate way for modelling and optimisation.
2.3.1.1 MODUELO
De Cortázar and Monzón (2007a) applied the simulation models of the landfill simulation program MODUELO versions 1 and 2 to analyse MSW landfills. An assessment was made to contribute to leachate flows collection and the investigation of biodegradation conditions through a dynamic simulation model.
Based on the data provided by the landfill chosen for the case study, a landfill model was constructed. Waste composition was calculated based on landfill records, considering the different types of wastes (municipal, commercial, special, demolition wastes, street cleanings, recycling plant rejects). The results of municipal solid waste characterization were done for recycling control. Two kinds of simulation were performed: hydrologic and biodegradation simulation.
The second version of the software, MODUELO 2, was used by the same authors for monitoring environmental protection measures in municipal solid waste landfills (de Cortázar and Monzón, 2007b). The software proved to efficiently reproduce general landfill emission tendencies and simulate biodegradation processes.
2.3.1.2 DESASS
DESASS (DEsign and Simulation of Activated Sludge Systems) is a software tool for designing, simulating and optimising wastewater treatment plants. The basis of the program is a mathematical model that simulates physical, chemical and biological processes in WWTPs.
The software is capable to calculate the performance under steady and transient state of complete treatment schemes. So far, it has been applied for new WWTP designs, analyses and upgrade of existing WWTPs, development of new treatment schemes and control systems, as well as staff training.
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Assessments were shown through plant configuration changes and comparisons with various scenarios that the application of DESASS is straightforward (Ferrer et al., 2008).
2.3.2 Software interface for SWM optimisation
Abou Najm and El-Fadel (2004) developed a generic Excel-Visual Basic environment for an integrated solid waste management optimisation model. The introduced ISWM strategy takes important features into account, including waste management alternatives and technologies, economical and environmental costs and their applicability to specific areas.
User friendliness was a major concern during the development of the interface. The reason for applying mathematical programming in contrast with life cycle assessment was given. The described mathematical formulation is a linear programming model to be used in systematic analysis of the ISWM problem. The model takes generation sources, processing facilities, biological and thermal treatment facilities as well as landfills into account. The constraints include mass balance, capacity and material limitations, and policy implementation constraints.
The required data input can be given by the user. The interface generally consists of separate Excel worksheets. The software interface is capable to generate the required matrices of any size. However, the straightforward limitations of this solution are those of Excel and Visual Basic. The number of decision variables, for example, depends on the total number of columns allowed by Excel. At that time this limit was 28 (256), however, it increased in recent versions. In Excel 2007 the new limit is theoretically 214, i.e. 16,384 but it depends on the system configuration. It would be a good experiment to test the interface in more recent hardware and software environments.
2.3.3 General solvers
There is a wide variety of mathematical programming solvers on the market. After setting the mathematical model for a given problem, they can be effectively applied for specific scenarios even in waste management. Some of these software tools are small programs, others are embedded in a large mathematical package. The revisions conducted by the Author were focused mainly on individual solvers.
2.3.3.1 LINGO
Failure analysis of integrated SWM systems contributes to the regionalization assessment and provides risk-informed strategies. Chang and Davila (2006) used the software package LINGO as the solver of the mathematical programming problem of regional solid waste management system optimisation. The minimax regret (MMR) criterion frames the concept of loss of opportunity in decision making when alternative outcomes are possible. Different models were used to consider the level of regret. Implications were examined along with the optimal solid waste routing options of various conditions.
The software analysis considered several factors, including regret minimisation, the closure of other landfills, and upcoming composting facilities. The approach is helpful for regional planners and might have an impact on ideal decision making through the characterization of solid waste streams in regional areas in order to support optimal separation among different waste treatment and disposal options.
2.3.3.2 Modeling Programming Language
General optimiser tool Modeling Programming Language (MPL) v4.2 (Maximal Software, 2009) was used as the solver for the mixed integer programming model described by Badran and El-Haggar (2006) in order to optimise municipal solid waste management. The proposed model was optimised by minimising the MSWM system cost.
The software was used for solving linear, integer and mixed integer programming models.
More specifically, Branch and bound methodology was applied. The criterion for choosing the
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optimal combination of is the minimum value of the objective function which corresponds to minimum cost. Imputs were changed to cosider the variety of scenarios. A new set of constraints were developed to replace the source generation balance set of constraints.
Their main challenge was to define the best mix of collection station capacities to be evaluated in their respective scenarios. Conclusion could be set based on the evaluation of results, sensitivity analysis, and post results calculations.
Although the paper describes a regional MSW management optimisation only, potentials of the methodology can extend it to entire MSW management systems. So it would be capable to consider the routing of collection, transfer vehicles, and the frequency of waste collection.
2.3.4 Environmental Management Software (EMS)
EMS packages are comprehensive management and reporting applications for tracking and managing waste flows through the supply chain. Waste data are up-to-date and are available to all users across organizations via intranet or the internet. EMS makes environmental and safety information available in accordance with local, city, county and international regulations. They are developed for resource optimisation processes and support efficient chemical management at user-level. Environmental management software packages meet complex and wide-ranging needs of environmental and material management. They include chemical reference database support.
2.3.5 Special software for optimising HENs in thermal treatment of waste Stehlík (2007) applied a specialised database to select suitable heat exchanger types in heat recovery of thermal processing of various kinds of waste. Specific features of the process fluids were taken into account. The contribution is capable to find the optimum solution for that subproblem. Furthermore, its application might be useful to avoid possible serious operating problems, including excessive fouling, thermal expansion, and leakages (Stehlík, 2009). For hot gas applications, for example, the specialized database differentiates conventional and special heat exchangers. The first group includes various shell-and-tube heat exchangers, as well as double-pipe, plate-type, and heat-pipe heat exchangers. The special ones include coaxial heat exchangers, double U-types, sludge applications, and radiation recuperators. Process fluid, inlet temperature, inlet pressure and temperature fluctuation are considered for both hot and cold streams.
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CHAPTER 3
COMPREHENSIVE SOFTWARE
Many research papers have been devoted to tasks of optimising energy generation, conversion, transmission, exchange, integration and utilisation. However, there are some additional issues which have important influence on the quality and quantity of energy supply and waste-to-energy systems. The Author of the thesis has explored up-to-date software tools which could help to assess and improve all these issues (Sikos and Klemeš, 2008b).