Modern manufacturing processes assume efficient utilization and recycling of natural resources whenever possible. Over the past decade paper recycling has progressed from 33.5% in 1990 to just above 48% in 2002.1 Indeed, for certain select grades, (newspaper and old corrugated containers) greater than 70% is currently being recycled. In contrast, mixed office waste and colored directory papers are often underutilized. A major difficulty in recycling these grades of paper is the problems associated with decolorizing the dyes present in the paper.2 Of the commonly used paper dyes, the stilbene dye Direct Yellow 113 and methine dye Basazol 46L are notorious4 for poor bleachability with the commonly used chemical bleaching agents including chlorine dioxide, oxygen, hydrogen peroxide and sodium dithionite. The ability of white-rot fungi to decolorize colored effluents containing textile dyes is currently the subject of intensive research efforts. The secreted enzymes involved in dye decolorization include manganese peroxidase, lignin peroxidase and laccase. Laccase, a lignolytic enzyme, has also been studied for many years for the biobleaching of wood pulps. The ability of laccase to delignify pulp is greatly enhanced by the addition of small molecule mediators such as 2-2´ azinobis (3-ethylbenzthiazoline-6-sulfonate) (ABTS) and 1-hydroxybenzotriazole (HBT). This research project focused on applying laccase combined with a mediator to decolorize C.I. Direct Yellow 11 and Basazol 46L. Three mediators were tested: ABTS, HBT and violuric acid. Laccase/ABTS was most effective with 60% of the color being removed. The level of color removal was maintained at 60% even when ABTS concentration was lowered from 5 mM to 0.01 mM. When laccase/1 mM ABTS was applied to Direct Yellow 11 in solution, the majority of color loss occurred within 60 minutes. The ability of soybean (SBP) and horseradish (HRP) peroxidases and laccase to decolorize Direct Yellow 11 and Basazol 46L in solution was also examined. The results demonstrated that these two recalcitrant dyes could be effectively decolorized by enzymatic treatments by horseradish peroxidase, soybean peroxidase, and laccase with ABTS as mediator. SBP is effective from pH 4.5 to 8.5. The stilbene dye Direct Yellow 11 responded to both SBP and laccase/ABTS. For the methine dye Basazol 46L, SBP was a more effective treatment than HRP or laccase/ABTS. Basazol 46L responded quickly to SBP treatment with 74% reduction in signal intensity within 5 minutes. To evaluate the effectiveness of laccase/ABTS treatment, pulp dyed with Direct Yellow 11 and three commercial colored pulps were subjected to seven different bleaching treatments. These treatments consisted of 1)laccase/ABTS; 2)laccase/ABTS followed by alkaline extraction; 3)laccase/ABTS followed by bleaching with sodium dithionite; 4)oxygen bleaching; 5)oxygen bleaching followed by dithionite treatment; 6)alkaline hydrogen peroxide bleaching; and 7)alkaline peroxide bleaching followed by dithionite treatment. The best results were obtained by including reductive bleaching with sodium dithionite. For Direct Yellow 11 dyed pulp, laccase/ABTS followed by dithionite yield comparable reduction in color to oxygen or peroxide followed by dithionite.

Landfill and mixed wastes are more expensive to dispose of than sorted wastes, and also decrease the possibilities for recycling of wastes. This thesis aimed towards determining what the potential benefits could be with leasing a sorting site and whether or not Destroy RC AB should introduce a sorting site to their business from a primarily economic perspective. The materials included in landfill and mixed wastes were determined and were prioritized differently depending on the economic and environmental benefit from sorting and recycling each material. If a sorting site was introduced to Destroy’s network of processes, unsorted waste types would be sent to the sorting site from demolition sites instead of to landfill and recycling sites. Scenarios with different variations of amounts of wastes at the sorting site, compositions of wastes, truck types used for transports, and sorting speeds were studied and used for total cost analyses

ABSTRACT Bioreactor landfill operation has been promoted as a means of accelerating the degradation of waste for over 30 years. Accelerating the degradation of waste enables better predictability in biogas production and reduces aftercare costs. Most bioreactor landfill trials focus on the effect of leachate recirculation on otherwise conventional landfill cells. However, there is a range of design and operational measures that can be implemented with standard landfilling machinery to further enhance degradation. This thesis explores degradation rates that can be achieved in a landfill cell, designed to maximise degradation rate, with the constraint that it be constructed by standard earthmoving equipment, the waste be crudely shredded by sheep foot compactors to expose waste, and leachate recirculation be operable by landfill personnel. The major departures of these test cells from a conventional landfill cell operation were: the cells were only 3m deep; MSW loaded into the cell was crushed and bags ruptured with a sheep foot compactor; MSW was pre-mixed prior placement with digested sludge, as a ratio such that the buffering capacity of the sludge was equivalent to an amount of NaHCO3 known to successfully buffer the digestion of packed beds of MSW (10gL-1 NaHCO3 in packed bed at field capacity moisture content plus excess leachate equal to 10% of the bed volume (Lai et al 2001); and the waste was placed rather than compacted into the cell. The thesis examines the performance of two test cells, the second only containing MSW and inoculated and buffered by sequencing with the first. These performances are compared with an exhaustive set of control digestions in 200L laboratory reactors. The laboratory reactors were packed with 50kg sub-samples of the waste used in the cells, shredded to sub 5cm size. The laboratory reactors primarily focussed on the effect of temperature on degradation rates, to identify the optimum degradation rate for this sludge and MSW mixture. The laboratory scale reactors produced 231 L and 202 L of methane per kgVS at the mesophilic temperatures of 38°C and 45°C respectively. The degradation was faster in the 45°C reactor where methane production was completely exhausted after 35 days. A laboratory reactor operated at 55°C reactor showed little degradation activity. The pH of this reactor was initially over 8.5, and ammonia inhibition was suspected. However, the reactor did not respond to pH adjustments with hydrochloric acid, and subsequent step decreases in temperature did not have an effect until 47°C, where degradation suddenly accelerated. This suggests the methanogenic consortia in the sludge could not adapt to thermophilic temperatures. This was confirmed in the 63°C reactor which acidified and did not produce methane, until leachate from this reactor was transferred to the 45°C reactor where an established methanogenic community converted the soluble COD to methane. In order to compare laboratory reactor performance with the general literature, pure cellulose was added in a fed-batch fashion to the stabilised 38°C and 47°C leach-beds. The beds were fed under starved conditions, to clearly distinguish degradation products from the cellulose from background levels. This also allowed for the estimation of biomass growth by measuring the uptake of NH4-N, as all other bio-available N sources such as protein and amino acids were reduced to NH4-N under these starved conditions. Hydrolysis rates were determined to be 0.12±0.01 d-1 and 0.14±0.026 d-1 at the 38°C and 47°C temperatures. Degradation in the two test cells was completed within a 7 month period. Temperature in the cells was maintained between 25 – 30°C by biological activity, levels that were above ambient temperatures, but below ideal mesophilic conditions. Methane composition rapidly approached 50% in both cells, and biogas flow rates were consistent with a degradation timeframe in the order of less than year. Full flow rate data was not obtained from these trials due to mechanical problems with flow meters, however vigorous gas production was evident throughout the trial by monitoring gas composition, and the ballooning effect of the top cover. To confirm the degradation rates in the test cells, samples were collected from the second test cell and digested in laboratory reactors. Methane yields were only 2.4 and 6.4 L CH4 kgVS-1 confirming virtual exhaustion of biogas potential within 7 months of sequencing this MSW cell with the first MSW:sludge test cell. This is the first systematic experimental program that places the degradation performance of a test cell in the context of the potential degradation rate achievable with fine shredding, temperature control and thorough inoculation and buffering. Economically, in cases where degradation residues are left insitu as in landfills, the degradation enhancement in the test cells would effectively yield as much benefit as enhancing the degradation rate to a two to three week timeframe typical of an anaerobic digester (Clarke 2000).

Increasing waste production is the reason why it is important to focus in more detail on profitable and cost side of waste economy. This diploma thesis deals with the area of garbage collection as a fundamental part during garbage their cumulation in a particular location and follow-up liquidation or preservation. At first the theoretical background of Chinese Postman Problem is described as a cornerstone for garbage collection models. Extensions of this problem have to be considered to be closer to reality. Then waste management in the city of Poděbrady is thoroughly described. In the final part of diploma thesis aforementioned theoretical models are applied on real data obtained from the city of Poděbrady waste department. Heuristic algorithms are an essential part of thesis as a replacement of optimizations models that cannot be used in some cases due to high requirements on computational time.

Construction of new buildings and restoration of existing buildings is causing waste. Often,the waste consists of a mixture of different materials, also called “mixed waste”. Waste fromconstruction sites stands for over 35 % of the entirely waste in amount Sweden and is aconsiderable contributing factor to the carbon dioxide emissions. It is very important that theamount of waste is reduced, and different materials are separated in order to achieve increasedsustainability. This report will examine the alternatives for building companies to minimisethe mixed waste fraction from their construction sites, using waste statistics from constructionprojects in the northern part of Sweden and a survey answered from the site managers at theconstruction company. The results show that mixed waste is one of the largest fractions ofwaste from construction projects, and it is also one of the most expensive fractions. Theenvironmental benefits and the economic gain a reduced mixed waste can contribute with, isan important step to reduce the climate impact from construction work. This paper willhopefully inspire some new ideas for minimising the mixed waste fraction at constructionproject, for example the displaying of containers for the different waste fractions. To separatethe different waste fractions efficiently and is beneficial regarding the environmental impactand the economy of the building companies.

Plastic waste from industries and manufacturing development poses a significant issue due to its exponential environmental and economic impacts. This study aims to optimize the industrial plastic waste management by exploring the different ways of handling this waste for small to medium-sized enterprises (SMEs) in the energy production sector in line with the EU and Swedish waste directives. This study draws on a mixed research method and a case study. The results disclose that proper sorting system, the implementation of waste policies and regulations, and informed waste practices based on knowledge and education in plastic waste management are essential for the implementation of sustainable plastic waste management system. While aspects such as the market demand and economic efficiency, the presence of hazardous and waste contamination, and the waste volume were identified to hinder the implementation. However, this study explored sorting techniques through the lens of practical strategies, introducing innovative solutions to address the challenges associated with mixed and contaminated industrial plastic waste. By leveraging the selective dissolution sorting technique, the study proposed the waste sorting process as essential practices to pave the way for sustainable waste management practices in SMEs in the energy sector. The findings not only contribute to the existing knowledge in waste management but also offer practical recommendations for businesses striving for efficient waste management. However, these findings necessitate implementing new protocols for waste sorting and changes in waste flow to ensure effective sorting practices. This could require investments in equipment, training for employees, creating specialized waste management department or establishing cross-functional teams to oversee waste sorting initiatives.