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RECENT ADVANCEMENTS IN THE DEVELOPMENT OF MATERIALS AND PRODUCTS FROM RENEWABLE RESOURCES M. van der Zee, E. Pras, J. van Haveren, R. van Tuil ATO, Business unit Renewable Resources, Department Polymers, Composites, and Additives, P.O. Box 17, NL-6700 AA Wageningen, the Netherlands. 1. Abstract Natural materials, i.e. renewable resources, are a versatile and very promising class of materials. Natural materials, either polymeric or not, often exhibit properties that can not be achieved with synthetic materials. Natural rubber, for example is still used for high performance tyres like aeroplane- and truck tyres since it outperformes synthetic materials like EPDM. ATO successfully performs developments in collaboration with industry leading to novel, innovative outlets for materials from natural origin. Examples of topics that receive considerable attention are polymer additives, adhesives, coatings and bioplastics. Bioplastics - i.e. thermoplastic polymers from renewable resources - have been available on the market for a long time but have failed to gain a significant market share so far. As a main reason, one can identify the unfavourable cost/performance ratio as compared to that of conventional petroleum based materials. Together with industrial partners, ATO works on the initiation of a breakthrough in the use of polymers from renewable resources by increasing the cost/performance ratio. The number of commercial applications for bio-based polymers can be increased when products are developed that utilise the advantageous properties of this type of materials. Examples of such properties that can be obtained with biobased materials are: a) excellent gas barrier properties (comparable with EVOH); b) straight forward processability into foam materials (without chemical blowing agents); c) biodegradability; d) anti-static properties; e) hydrophilic behaviour (therefore these materials are potentially good water-absorbent materials); f) excellent matrix material for encapsulation of natural ingredients (fertilisers, flavours etc.); and g) abundance and low cost. In this paper, examples are presented of recent advancements in the development of materials and products from renewable resources utilising one or more of these unique specific functionalities of natural feedstocks. The first example shows results in the field of sustainable additives for the plastic processing industry. A second shows the progress that has been made in the bioplastics area. |
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UTILIZATION OF BIODEGRADABLE KERATIN AND COLLAGEN-CONTAINING WASTES THROUGH ENZYMATIC TREATMENT P. G. Dalev University of Sofia, Faculty of Biology, Laboratory of New Protein Sources, boul. Dragan Tsankov 8, 1421 Sofia, Bulgaria 1. Abstract In the production of chicken meat the main waste are feathers and in the production of leather the main waste that remains after splitting of limed hides is fleshing (i.e., the lowest layer of the skin together with the underlying fatty tissue). Both wastes represent a problem for the industry since they pollute the environment. Their utilization is difficult since the feathers have a very rigid protein structure, and the fleshing contains too much water, lime and fat. But both wastes contain to much protein (feather - 80-90%, fleshing - 30-35% on dry mass basis). In this work, simple technologies for processing waste feathers and fleshing are depicted to produce a protein hydrolysate from feathers and raw gelatin, cattle tallow and protein hydrolysate from flashing. Both technologies are applicable to a large-scale production. |
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ECOTOXICOLOGICAL TRIALS WITH BAK 1095 (Bayer AG, Leverkusen) ACCORDING TO DIN V 54900 C. Bruns1), R. Gottschall1), B. de Wilde2) 1) PlanCoTec, Karlsbrunnenstr. 11 b, D - 37249 Neu Eichenberg, Germany 2) Organic Waste Systems (OWS), Dok Noord 4, B — 9000 Gent, Belgium 1. Abstract Within the frame of examinations with BAK 1095 (small-scale test according to DIN V 54900 part 3 and "controlled composting test " DIN V 54900-Part 2, No. 3), the following working hypothesis as postulated by J. Fritz (1999) in his PhD-Thesis was tested: the "negative ecotoxicological impact " of the biodegradable material BAK 1095, produced by Bayer AG, mainly bases on the emission of heavily toxic NH3. Fritz used the "controlled composting test" for the production of his compost and reached reproducibly negative results in bioassays (inter alia Daphnia, algae (Scenedesmus sp., Chlorella sp.) and cress) with compost containing 15 to 17 weight % of BAK - polymers. As a result of the applied method "controlled composting test", especially when using base materials with high nitrogen contents, NH3 and immature compost develop. According to Fritz, the compost with BAK showed considerably higher contents of total N, strongly increased pH-values and a higher elutable proportion of organic matter when compared to the control, as well as extremely high NH4-N-contents (55 to 78 times higher than the control without BAK). The working hypothesis could be backed up by our examinations, in pilot-scale tests (PlanCoTec) as well as under the conditions of the controlled composting test (OWS). In both tests, extremely high NH4-N contents were recorded in early stages of the composting of BAK 1095 as compared to the control without BAK addition. During the pilot scale composting NH4-N values were reduced by 99 %. In the controlled composting test, however, the NH4-values did not decrease. Thus, toxic impacts measures in bioassays with sensitive testing organisms (cress test for gaseous phytotoxic substances, daphnia ) took a parallel course to the ammonium contents. However, these impacts occurred independent from the addition of BAK 1095, when NH4-N levels were artificially raised to the same level as in treatments with BAKs by the addition of ammonium to the control treatments. Tests with test plant barley which is less sensitive against NH4-N/ NH3 showed no negative effects with the same compost. Therefore, it has to be assumed that the results as found by Fritz are mainly, if most probably not entirely caused by a pure NH3-effect. An additional cause is the chosen testing method. |
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COMPARISON OF TEST SYSTEMS FOR THE DETERMINATION OF THE BIODEGRADABILITY OF ORGANIC MATERIALS UNDER ANAEROBIC CONDITIONS J. Heerenklage1), F. Colombo2), R. Stegmann1) 1) Technical University of Hamburg-Harburg, Department of Waste Management, Harburger Schloßstraße 37, 21079 Hamburg, Germany 2) Politecnico di Milano, Facolta di Ingeneria, Piazza Leonardo da Vinci, 32 20133 Milano, Italy 1. Abstract The determination of the biodegradability of organic substances is of crucial importance for the product launch and for the disposal of these products. Biodegradable materials can be treated under aerobic as well as under anaerobic conditions. The investigation of biodegradability under aerobic environment conditions alone is not sufficient, for there are some materials, which are biodegradable under aerobic conditions, but an anaerobic biodegradation cannot be observed to the same extent. This is to be examined by use of standardised test methods. For the determination of the biodegradability under anaerobic conditions bench scale studies were carried out using on two different test systems according to the ISO CD 14853. These were then compared. In one of these test systems, the gas production was measured with an Eudiometer using the principle of displacement volume. In the second test system, the gas production was measured via determination of gas pressure. Materials tested were Polyhydroxybutyrate (PHB), Poly-e-caprolacton (PCL) and EcoflexÒ . The assessment of the degree of biodegradability was carried out by determining gas production. The examinations have demonstrated, that with both test systems comparable results can be achieved. |
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THE WATER-SOLUBLE ORGANIC FRACTION AND ITS RELATIONSHIP TO THE DEGREE OF MATURITY OF ORGANIC MATTER DURING COMPOSTING. M. A. Sánchez-Monedero, A. Roig, M. P. Bernal. Department of Soil and Water Conservation and Organic Waste Management. Centro de Edafología y Biología Aplicada del Segura. CSIC. P.O.Box 4195. E-30080 Murcia. Spain. 1. Abstract The evolution of different components of the water-soluble organic matter, water soluble carbon (COW), carbohydrates and phenols were studied during the composting of six different mixtures of organic wastes prepared with sweet sorghum bagasse, cotton waste, sewage sludge, municipal solid waste, urea, pine bark and brewery sludge. The COW, carbohydrate and phenol concentrations decreased in the six composting mixtures as a consequence of the organic matter degradation carried out by the microbial activity. The intensity of this organic matter degradation and the evolution of the water-soluble compounds depended on the kind of material used in the starting mixtures. Therefore, these parameters were not considered suitable to be used as the basis for a general organic matter stabilisation index. The changes in the water-soluble organic carbon to water-soluble organic nitrogen ratio (COW/NOW) and the water-soluble organic carbon to total organic nitrogen ratio (COW/NOT) were considered to be suitable as general stabilisation indices since these ratios did not depend on the material used. The evolution of these two ratios showed a similar pattern during the composting of the six mixtures studied. All mature composts reached values for these ratios which were in agreement with the ranges proposed by other authors with other type of materials. These maturity indices were also compared with Lepidium Sativum L. germination assays and no phytotoxic effects were found in materials with COW/NOW and COW/NOT ratios values between the limits established for mature composts (COW/OW between the range 5-6, and COW/NOT < 0.40). |
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CO-DIGESTION - ENHANCING RECOVERY OF ORGANIC WASTE B. Purcell1) and E. I. Stentiford2) 1) WS Atkins, Woodcote Grove, Ashley Road, Epsom, Surrey, KT18 5BW, UK 2) School of Civil Engineering, The University of Leeds, Leeds, LS2 9JT, UK 1. Abstract Laboratory scale trials were carried out to anaerobically digest mixtures of biodegradable supermarket wastes and sewage sludge. 8 reactors were used, each 20 litres capacity operated mesophilically (35°C). The results showed that increasing organic loading rates from 2.5gVS/l.d to 6.0-6.5gVS/l.d resulted in a three-fold increase in biogas generation. Further increases in organic loading rates to 7.6gVS/L.d. promoted considerable deterioration in the performance of a number of the digesters. Digester performance was restored rapidly with the addition of an alkali to increase reactor pH to around neutral values. Digestate from both primary and co-digestion cells indicated valuable NPK concentrations, with digestate from co-digestion containing lower PTE concentrations for beneficial use. |
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REPORT PAPER - DRIVERS FOR BIODEGRADABLE/COMPOSTABLE PLASTICS AND ROLE OF COMPOSTING IN WASTE MANAGEMENT AND SUSTAINABLE AGRICULTURE R. Narayan Department of Chemical Engineering, Michigan State University, East Lansing, MI 48824 USA, www.msu.edu/user/narayan 1. Abstract Sustainability, industrial ecology, ecoefficiency, and green chemistry are the new principles that are guiding the development of the next generation of plastic and other products and processes. Thus, new products have to be designed and engineered from "conception to reincarnation" incorporating a holistic "life cycle thinking approach". The rationale and drivers for manufacturing eco-efficient, sustainable, and biodegradable/compostable plastics are discussed on the basis of global carbon cycling, design principles for the environment, and disposal/waste management infrastructures. Designing plastics, used in single-use disposable packaging and consumer goods, to be biodegradable and ensuring that they end up in composting systems is environmentally and ecologically sound. Composting as an ecologically important tool, not only for waste management but also for sustainable agriculture practices. Biodegradable plastics and biobased products based on annually renewable agricultural and biomass feedstocks can form the basis for a portfolio of sustainable, ecoefficient products that can compete and capture markets currently dominated by products based exclusively on petroleum feedstocks. Biodegradable plastic products are under commercialization by several small and major companies. Worldwide Standards for biodegradable/compostable plastics and certification/logo schemes are in place |
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