Compostable cutlery and waste management: an LCA approach

The use of disposable cutlery in fast food restaurants and canteens in the current management scenario generates mixed heterogeneous waste (containing food waste and non-compostable plastic cutlery). The waste is not recyclable and is disposed of in landfills or incinerated with or without energy recovery. Using biodegradable and compostable (B&C) plastic cutlery, an alternative management scenario is possible. The resulting mixed homogeneous waste (containing food waste and compostable plastic cutlery) can be recycled through organic recovery, i.e., composting. This LCA study, whose functional unit is "serving 1000 meals", shows that remarkable improvements can be obtained by shifting from the current scenario to the alternative scenario (based on B&C cutlery and final organic recovery of the total waste). The non-renewable energy consumption changes from 1490 to 128MJ (an overall 10-fold energy savings) and the CO(2) equivalents emission changes from 64 to 22 CO(2) eq. (an overall 3-fold GHG savings).     

Biodegradation Behavior of Some Vegetable Oil-Based Polymers

The potential biodegradability of several vegetable oil-based polymers was assessed by respirometry in soil for 60–100 days at temperatures of 30–58°C. Films of soybean oil and linseed oil which were oxidatively polymerized (Co catalyst) on a kraft paper support were 90%–100% mineralized to CO₂ after 70 days at 30°C. Mineralization of polymerized tung oil to CO₂ was much slower than soy or linseed oils. Mineralization of epoxy resins made from epoxidized soybean oil (ESO) and aliphatic dicarboxylic acids was rapid while mineralization of similar resins made with a triacid (citric) was slower. There was no significant degradation of polyamine/ESO resins after 100 days at 58°C. Mineralization of the available carbon in vegetable oil polyurethanes and cationically polymerized ESO was less than 7.5% after 70 days at 30°C and 25 days at 55°C compared to 100% for soybean oil. From these results, it appears that triglycerides highly cross-linked with non-degradable linkages are not biodegradable to a significant extent while triglycerides cross-linked with hydrolysable bonds such as esters remain biodegradable.     

WEEE recycling: Pyrolysis of fire retardant model polymers

Pyrolysis treatments of model polymers were made with the aim of studying the recycling of wastes from electronic, electric equipment containing brominated flame retardants. Pyrolysis of flame retarded high impact polystyrene and epoxy resins were made both in flow and closed systems. Products of pyrolysis were analysed with FT-IR spectroscopy and GC-MS and the evolution of bromine was followed with a bromine ion specific electrode. The effect of alkali on pyrolysis was also studied demonstrating, as far epoxy resin is concerned, to be effective on decreasing bromine content in oil and volatile products leading to the recovery of bromine from the residue by washing. The alkali treatment was shown to be less effective in styrenic polymers containing brominated flame retardants.     

Biodegradable Polymers- A Review on Recent Trends and Emerging Perspectives

Recent trends in biodegradable polymers indicate significant developments in terms of novel design strategies and engineering to provide advanced polymers with comparably good performance. However, there are several inadequacies in terms of either technology or cost of production especially in the case of applications in environmental pollution. So, there is a need to have a fresh perspective on the design, properties and functions of these polymers with a view to developing strategies for future developments. The paper reviews the present state-of-art on biodegradable polymers and discusses the salient features of the design and properties of biodegradable polymers. Special emphasis is given to the problems and prospects of (1) approaches adopted to make non-biodegradable synthetic polymers such as polyethylene biodegradable and (2) biodegradable polymers and copolymers made from renewable resources especially poly(lactic acid) based polymers and copolymers which are emerging as the candidate biodegradable materials for the future.     

Rheological Behavior Under Shear and Non-Isothermal Elongational Flow of Biodegradable Polymers for Foam Extrusion

The production of many items, in particular for food packaging applications, is based on foam extrusion and thermoforming. These operations require the use of polymers which can grant some specific rheological properties, both under shear and elongational flow. In this work, the behavior of some biodegradable polymers [Mater-Bi^® and poly(lactic acid)] under shear and non-isothermal elongational flow was investigated and compared with a traditional, non-biodegradable polymer, in order to assess their suitability for industrial-scale foam extrusion and thermoforming. The rheological characterization evidenced the differences between the different biodegradable polymers and the reference polystyrene (PS), as well as the effect of humidity on their main rheological properties. This can be of great interest in helping to find an optimum solution in replacing PS for the production of food packaging items.     

Study of the future land use of a contaminated site: Preferences versus potential use

Worldwide, agencies with high levels of contamination are faced with decisions about remediation and restoration. These decisions should be informed by future land use and long‐term stewardship goals. In the United States, the Department of Energy has lands in some 34 states that require cleanup. They are involved in massive remediation and restoration efforts on lands from the Cold War legacy and wish to reduce their overall footprint. Understanding future land use preferences is essential for determining the nature and degree of remediation and restoration. The objective of this study was to examine future land use preferences for the Department of Energy's Los Alamos National Laboratory as a function of ethnicity for attendees at the Los Alamos Gun Show in New Mexico (1999), and to determine whether their own activity influences future land use preferences. The highest preferred future land uses for Los Alamos National Laboratory were hiking, camping, National Environmental Research Park, and birdwatching, followed by hunting and fishing. Increased nuclear waste storage and building homes and factories were rated the lowest. Further, hiking and camping were rated higher than at two other DOE sites. There were few ethnic differences, although American Indians rated camping, hiking, building houses, and returning the land to American Indians higher than did others, and Hispanics rated using it for a preserve as a higher preferred land use than all others. The differences, however, were not great. Relative ratings for using the land for hunting and fishing were directly related to individual frequency of hunting and fishing for both whites and Hispanics, indicating that people perceive the importance of land use by how they want to use it. Ratings for hiking and camping were not related to the number of days people hiked and camped, suggesting these are general preferences overall. © 2004 Wiley Periodicals, Inc.     

Development of intelligent sorting system realized with the aid of laser-induced breakdown spectroscopy and hybrid preprocessing algorithm-based radial basis function neural networks for recycling black plastic wastes

Plastic recycling has been the key issue for reducing environmental problems and resolving resource depletion. To improve the recovery rate of plastics, the plastic wastes are correctly identified according to their resin type. However, the identification system, which is able to identify black plastics according to not only the type of black plastics but also the grade of resins correctly, has not been introduced. In this paper, laser-induced breakdown spectroscopy, intelligent algorithms and preprocessing algorithms are used to improve the identification of black plastics such as polypropylene, polystyrene (PS), and acrylonitrile butadiene styrene (ABS). The laser-induced breakdown spectroscopy is capable of obtaining the characteristic spectrum regardless of material’s physical state. To extract the new features which are very valuable to improving learning performance, increasing computational efficiency, and building better generalization models from the obtained spectra through laser-induced breakdown spectroscopy, the hybrid preprocessing algorithm, composed of principal component analysis and independent component analysis, is used. In addition, the intelligent algorithm named the extended radial basis function neural networks inheriting the advantages of fuzzy theory and neural networks is used to identify black plastic samples into several categories with respect to their resins. The proposed identification system, composed of three parts such as laser induced breakdown spectroscopy, hybrid preprocessing algorithms, and an efficient intelligent classification algorithm, is able to show the synergy effect on the black plastic identification problem. From several experimental results, it can be seen that the identification system based on laser-induced breakdown spectroscopy and the intelligent algorithm is used for identification of black plastics by resin type.     

Compatibilization Improves Performance of Biodegradable Biopolymer Composites Without Affecting UV Weathering Characteristics

With growing interest in the use of eco-friendly composite materials, biodegradable polymers and composites from renewable resources are gaining popularity for use in commercial applications. However, the long-term performance of these composites and the effect of compatibilization on their weathering characteristics are unknown. In this study, five types of biodegradable biopolymer/wood fiber (WF) composites were compatibilized with maleic anhydride (MA), and the effect of accelerated UV weathering on their performance was evaluated against composites without MA and neat biopolymers. The composite samples were prepared with 30 wt% wood fiber and one of the five biodegradable biobased polymer: poly(lactic) acid (PLA), polyhydroxybutyrate (PHB), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), Bioflex (PLA blend), or Solanyl (starch based). Neat and composite samples were UV weathered for 2000 h (hours), and characterized for morphological, physical, thermal, and mechanical properties before and after weathering. Compared to composites without MA, composites containing MA grafted polymers exhibited improved properties due to increased interfacial adhesion between the fiber and matrix. Upon accelerated weathering, thermal and mechanical properties of 70% of the samples substantially decreased. Surfaces of all the samples were roughened, and drastic color changes were observed. Water absorption of all the samples increased after weathering exposure. Even though the compatibilization is shown to improve composite properties before weathering, it did not affect weathering of samples, as there were no considerable differences in properties exhibited by the composites with MA and without MA after weathering. The results suggest that compatibilization improves properties of biodegradable biobased composites without affecting its UV degradation properties.     

Recycled Polyethylene Composites Reinforced with Jute Fabric from Sackcloth: Part II-Impact Strength Evaluation

Environmental problems are motivating recycling actions and reuse alternatives for materials with main focus for the application of those renewable and biodegradable materials such as lignocellulosic fibers. Composites reinforced with such fibers are being considered by several industrial sectors, not only from the environmental safety, but also from economic considerations and improved properties. This paper, which is continuation of the work (Part I) by the authors’ use of the recycled polyethylene and used jute fabrics, presents evaluation of its toughness measured by the impact energy using both Izod and Charpy methods. Fabric content used is up to 40 wt. %. It is found that the incorporation of both types (new and used) of jute fabric significantly increased the impact energy of composites, with higher values associated with the new jute fabric. Fractographic analysis revealed that weaved configuration of the jute fibers and their low interfacial resistance with the matrix are responsible for the observed impact performance of these composites.     

Humidity- and Age-Tolerant Starch-Based Sponge for Loose-Fill Packaging

Loose-fill packaging sponges were extruded from mixtures of 54–62% hydroxypropylated (HP 5%) amylomaize V (50% amylose) and wheat starches, 17–24% synthetic polymer, 13% water, 7% blowing agent(s), and 0.5% nucleating agent. One product made from 28% HP wheat starch, 28% HP amylomaize V starch, 12% ethylene vinyl alcohol (EVOH) copolymer, 8% polystyrene (PS), and 3% polystyrene maleic anhydride (PSMA) copolymer, plus the other raw materials, had a compressibility and resilience that matched those of expanded polystyrene (EPS), although its bulk density was four times higher. The starchy sponge showed 16% shrinkage in volume at 90% relative humidity and was 2% soluble in excess water, both at 25°C. After aging for 18 months near 25°C, the HP starchy sponge gave only a trace of fines in a simulated shipping test, compared to 20% fines from a biodegradable, starch-based, loose-fill sponge of commerce.     

Energy implications of the thermal recovery of biodegradable municipal waste materials in the United Kingdom

Waste management policies and legislation in many developed countries call for a reduction in the quantity of biodegradable waste landfilled. Anaerobic digestion, combustion and gasification are options for managing biodegradable waste while generating renewable energy. However, very little research has been carried to establish the overall energy balance of the collection, preparation and energy recovery processes for different types of wastes. Without this information, it is impossible to determine the optimum method for managing a particular waste to recover renewable energy. In this study, energy balances were carried out for the thermal processing of food waste, garden waste, wood, waste paper and the non-recyclable fraction of municipal waste. For all of these wastes, combustion in dedicated facilities or incineration with the municipal waste stream was the most energy-advantageous option. However, we identified a lack of reliable information on the energy consumed in collecting individual wastes and preparing the wastes for thermal processing. There was also little reliable information on the performance and efficiency of anaerobic digestion and gasification facilities for waste.     

Viscosity of Soy Protein Plastics Determined by Screw-Driven Capillary Rheometry

Soy protein plastics are a renewable, biodegradable alternative to fossil fuel-based plastic resins. Processing of soy protein plastics using conventional methods (injection molding, extrusion) has met with some success. Viscosities of processable formulations that contain soy protein along with the necessary additives, such as glycerol and cornstarch, have not been reported, but are necessary for extrusion modeling and the design of extrusion dies. Resins consisting of soy protein isolate-cornstarch ratios of 4:1, 3:2, and 2:3 were plasticized with glycerol and soy oil, compounded in a twin screw extruder and adjusted to 10% moisture. The effects on viscosity of added sodium sulfite, a titanate coupling agent and recycling were evaluated using a screw-driven capillary rheometer at shear rates of 100–800/s. The viscosities fit a power-law model and were found to be shear thinning with power-law indices, n, of 0.18–0.46 and consistency indices, m, of 1.1 × 10⁴–1.0 × 10⁵. Power-law indices decreased and consistency indices increased with increasing soy protein-to-cornstarch ratio and in the absence of sodium sulfite. Addition of the titanate coupling agent resulted in increased power-law index and decreased consistency index. Viscosities at a shear rate of 400/s decreased with recycling, except for the 4:1 soy protein isolate to cornstarch formulation, which displayed evidence of wall slip. Power-law indices were unaffected by recycling. Viscosities in the tested shear rate range were comparable to polystyrene and low-density polyethylene indicating soy protein plastics are potential drop-in replacements for commodity resins on conventional plastics processing equipment.     

Process,Characterization and Biodegradability of Aliphatic Aromatic Polyester/Sisal Fiber Composites

The biodegradability, morphology, and mechanical properties of composite materials made of Poly(butylene adipate-co-terephthalate) (PBAT) and sisal fiber (SF) were evaluated. Composites containing acrylic acid-grafted PBAT (PBAT-g-AA/SF) exhibited noticeably superior mechanical properties due to greater compatibility between the two components. The dispersion of SF in the PBAT-g-AA matrix was highly homogeneous as a result of ester formation between the carboxyl groups of PBAT-g-AA and hydroxyl groups in SF and the consequent creation of branched and cross-linked macromolecules. Each composite was subjected to biodegradation tests in Rhizopus oryzae compost. Morphological observations indicated severe disruption of film structure after 60 days of incubation, and both the PBAT and the PBAT-g-AA/SF composite films were eventually completely degraded. Water resistance of PBAT-g-AA/SF was higher than that of PBAT/SF, although weight loss of composites buried in Rhizopus oryzae compost indicated that both were biodegradable, even at high levels of SF substitution. The PBAT-g-AA/SF films were more biodegradable than those made of PBAT, implying a strong connection between these characteristics and biodegradability.     

Reutilization of thermostable polyester wastes by means of agglomeration with phenolic resins

We report on the possibility of obtaining organic polymeric matrixes allowing the development of new high performance fire-resistant products by recycling downsized thermostable waste materials. Phenolic resins have been used as binders for recycled waste. Furthermore, considering that reinforced plastic triturations have superior properties (chemical, mechanical, water resistance, etc.) to wood agglomerates, significant advantages over conventional materials are anticipated. In summary, we propose a viable solution to some of the known problems caused by the consumption of wood and to the needs of strengthened plastic processing engineering. Using resins as a binder, several fire-resistant prototypes were prepared from polyester waste, and their mechanical properties, thermal stability, and fire-resistant properties were analyzed.     

Analysis of Biodegradability of Three Biodegradable Mulching Films

The development of biodegradable mulching films is a great direction for environment protecting and oil saving problems. In this paper, it was used three kinds of biodegradable mulching films named a, b and c (different ratio between modified starch and poly-CL with pro-oxidant additives) in microorganism culture test and soil burial test was investigated under laboratory conditions. The index of degradation was assessed by visual observation, weight loss and SEM analysis from quantitative and qualitative aspect. The results of both tests showed that these biodegradable mulching films were more readily degraded than the common plastic film. The percentage weight loss was in sequence of biodegradable mulching film c > biodegradable mulching film b > biodegradable mulching film a, while common plastic film basically had no changes. Weight loss was not as obvious as the visual degradation and suggested broader types of microbial attack. SEM analysis clearly indicated that the changes of surface morphology of these samples after the soil burial exposure.     

Test methods to aid in the evaluation of the diversion of biodegradable municipal waste (BMW) from landfill

This response follows on from a recent discussion by Sánchez (2009) on test methods to aid in the evaluation of the diversion of biodegradable municipal waste (BMW) from landfill. Test methods to assess the biodegradability/biodegradable content of organic waste are of great interest across Europe for different purposes, such as landfill acceptance criteria, monitoring treatment facility performance and for monitoring the diversion of biodegradable municipal waste (BMW) from landfill. Many studies have recently attempted to correlate short-term test methods with long-term anaerobic test methods. This response discusses recent findings and conclusions made by Sánchez (2009) and describes recent work undertaken at Cranfield University to develop the enzymatic hydrolysis test (EHT) method. The EHT has previously shown potential as a short-term, non-biological, biodegradability assessment tool, however there is a requirement to further develop this test method. We conclude that aerobic and anaerobic biological test methods are not the only suitable methods of assessing waste treatment process performance; and that alternative methods such as EHT are feasible and potentially suitable.     

An Overview on the Mechanical Behaviour of Biodegradable Agricultural Films

The mechanical behavior of various types of biodegradable materials depends, mainly, on their chemical composition and the application conditions. Various additives are added into the bioblends to improve their properties, which sometimes even reach the levels of the conventional plastics. It is well known that the environmental conditions during production, storage, and usage of these materials influence their mechanical properties. Ageing during the useful lifetime also causes great losses in the elongation. In the present paper, the overall mechanical behavior of biodegradable films, which may be considered suitable for agricultural applications, but also of partially biodegradable films, is reviewed and analyzed. Selected critical mechanical properties of films before their exposure to biodegradation are investigated and compared against those of conventional agricultural films.     

Experimental Processing of Biodegradable Drip Irrigation Systems—Possibilities and Limitations

The increased cost associated with the waste removal and disposal of conventional agricultural plastic in contact with the soil combined with the gradually decreasing cost of the biodegradable plastics allowed the commercialization of biodegradable mulching films. Since the conventional thin wall or tape drip irrigation system lies under the mulching film and is used for one season only, it would be desirable to replace it with a biodegradable one. This paper presents the results of a research work investigating the possibilities and limitations in developing biodegradable drip irrigation thin wall pipes and pipes. The first ever experimental biodegradable drip irrigation thin wall pipes were produced. Rigid pipes were also produced for experimental purposes. Manufacturing problems were encountered in the processing of the biodegradable drippers and irrigation thin wall pipes with the experimental materials due to the complex formulation of the raw materials and the fact that the machinery used was specifically designed for PE processing. Experimental biodegradable thin wall pipes made of Bioflex with embedded drippers made of Mater-Bi were produced. The processing problems encountered with the production of thin wall pipes were surpassed during the experimental production of rigid type irrigation pipes. A biodegradable rigid irrigation pipe made of a grade of Mater-Bi, with embedded cylindrical drippers made of another grade of Mater-Bi was produced successfully. A better understanding of the thermal profile of the biodegradable raw materials and the use of processing equipment adapted to this profile might allow in the future the manufacturing of thin wall drip irrigation pipes for agricultural applications, and the use of alternative biodegradable materials.     

Biodegradable Composites Containing Chicken Feathers as Matrix and Jute Fibers as Reinforcement

This research demonstrates that chicken feathers can be used as matrix to develop completely biodegradable composites with properties similar to that of composites having polypropylene (PP) as matrix. Feathers are ubiquitous and inexpensive but have limited industrial applications. Feathers have been preferably used for composite applications due to their low density and presence of hollow structures that facilitate sound absorption. However, previous approaches on using feathers for composites have used the whole feather or the feather fractions as reinforcement with synthetic polymers as matrix resulting in partially degradable composites. In addition, the hydrophilicity of the feathers and hydrophobicity of the synthetic matrix results in poor compatibility and therefore less than optimum properties. Although it has been shown that feathers can be made thermoplastic and suitable to develop films and other thermoplastics, there are no reports on using feathers as matrix for composites. In this research, chicken feathers were used as matrix and jute fibers as reinforcement to develop completely biodegradable composites. Tensile, flexural and acoustic properties of the feather-jute composites were compared to PP-jute composites. Utilizing feathers as matrix could enable us to develop low cost 100 % biodegradable composites containing feathers or other biopolymers as the reinforcement.     

Performance and Environmental Impact of Biodegradable Films in Agriculture: A Field Study on Protected Cultivation

The performance, the degradability in soil and the environmental impact of biodegradable starch-based soil mulching and low tunnel films were assessed by means of field and laboratory tests. The lifetime of the biodegradable mulches was 9 months and of the biodegradable low-tunnel films 6 months. The radiometric properties of the biodegradable films influenced positively the microclimate: air temperature under the biodegradable low tunnel films was 2 °C higher than under the low density polyethylene films, resulting in an up to 20% higher yield of strawberries. At the end of the cultivation period, the biodegradable mulches were broken up and buried in the field soil together with the plant residues. One year after burial, less than 4% of the initial weight of the biodegradable film was found in the soil. According to ecotoxicity tests, the kinetic luminescent bacteria test with Vibrio fischeri and the Enchytraeus albidus ISO/CD 16387 reproduction potential, there was no evidence of ecotoxicity in the soil during the biodegradation process. Furthermore, there was no change in the diversity of ammonia-oxidizing bacteria in the soil determined on the basis of the appearance of amoA gene diversity in denaturing gradient gel electrophoresis.