Critical Review of Norms and Standards for Biodegradable Agricultural Plastics Part II: Composting

The critical review of norms and standards and corresponding tests to determine the compostability of biodegradable plastics, possibly applicable also to biodegradable agricultural plastics, shows that many norms concerning testing and labelling of compostable plastics have been established at the international level. Some of them are about plastic materials, some others are about products like packaging. The media and conditions of testing cover mainly the conditions designed for industrial composting facilities, and only a few concern home composting conditions. Considering that the end of life management of biodegradable agricultural plastic products will be done at the farm to reduce the management of the waste and also its cost, only a few of these norms are considered to be suitable for adaptation to cover also biodegradable agricultural plastic products. The biodegradability validation criteria under composting conditions, such as the threshold percentage of biodegradation and disintegration, the time and temperature, and the ecotoxicity, are presented for the main norms and standard testing methods. Based on these different norms and their content, a list of specs and technical requirements that could be adapted to meet farm composting conditions for agricultural compostable plastics is proposed. These requirements may be used as criteria for the establishment of a new integrative norm for agricultural compostable plastics.     

Comparative Biodegradation in Soil Behaviour of two Biodegradable Polymers Based on Renewable Resources

This work presents the last phase of long-term experimental studies on the biodegradation in soil behaviour of polymers destined for agricultural applications. The paper focuses on comparative studies between the biodegradation in soil behaviour of two important biodegradable polymers based on renewable resources: poly(lactic acid) (PLA) versus polyhydroxyalkanoates (PHA). Full-scale experiments were carried out during the period June 2008–January 2009. Different methods of exposure were applied in the case of polyhydroxyalkanoates, simulating the agricultural biodegradable mulching films use and their fate in soil after the end of their useful lifetime. The field results were compared with the results of biodegradation under controlled laboratory conditions simulating biodegradation in soil, using soil from the experimental field. Further, the field results were compared against the results of biodegradation under farm composting conditions.     

Critical Review of Norms and Standards for Biodegradable Agricultural Plastics Part Ι. Biodegradation in Soil

A critical review of norms and standards and corresponding tests to determine the biodegradability in soil for biodegradable plastics, possibly applicable also to biodegradable agricultural plastics, is presented. There are only a few norms available at the international level about biodegradable plastics in soil. The criteria, parameters and testing methodologies for the characterization, labelling and validation of the agricultural plastic waste streams with respect to possible biodegradation in soil according to existing international standards are analysed while the relevant controversies are identified. To derive the best suited for agricultural plastics specs and testing methods, the possible developments or adaptation of available specs, is investigated. Considering the existing types of biodegradable plastic products in agriculture and their effective life management at the agricultural field, only a few norms appear to provide suitable tests that could be adapted, following appropriate research work, for testing biodegradability in soil under real field conditions. It is shown that some major revisions are needed, with the support of systematic research work, before a new universal norm and standard testing methods become available for testing agricultural plastics for biodegradation under real, and highly variable, soil conditions. Based on the analysis of the different norms and their content it appears necessary to incorporate provisions for transferability of results to different soils and climates, validation of tests through a positive reference and also, set prerequisites for soil media. Long term biodegradation in soil prediction is another open issue.     

Environmental criteria in industrial facility siting decisions: An analysis

Environmental criteria are increasingly being employed in industrial facility siting, usually in multicriteria decision contexts, together with technical, socioeconomic and other considerations. This paper analyzes the criteria that have appeared in the published literature with the aim to offer guidance for their selection in a particular facility location problem. A number of alternative classification schemes are presented, first based on the most prevalent classification dimensions which are: the economy-environment relationship, purpose of the criterion, complexity, spatial and temporal scale, and level of measurement. The major scheme adopted draws from the economy-environment relationship and assigns environmental critera to one of seven categories: general characterizations of the environment, characteristics of individual environmental components, measures of the magnitude and intensity of the activity, measures of the nature and volume of wastes which are produced, characteristics of impacts on separate environmental media and receptors, general characterizations of environmental quality, and impacts on humans. Within each of these categories the criteria are analyzed in terms of the other classification dimensions. Common characteristics among the various criteria as well as future trends in their development are identified. This paper also discusses the most important factors conditioning the choice of criteria in a particular facility siting context and outlines a systematic procedure for their selection in real-world applications.     

Theoretical orientations in environmental planning: An inquiry into alternative approaches

In the process of devising courses of action to resolve problems arising at the society-environment interface, a variety of planning approaches are followed, whose adoption is influenced by—among other things—the characteristics of environmental problems, the nature of the decision-making context, and the intellectual traditions of the disciplines contributing to the study of these problems. This article provides a systematic analysis of six alternative environmental planning approaches—comprehensive/rational, incremental, adaptive, contingency, advocacy, and participatory/consensual. The relative influence of the abovementioned factors is examined, the occurrence of these approaches in real-world situations is noted, and their environmental soundness and political realism is evaluated. Because of the disparity between plan formulation and implementation and between theoretical form and empirical reality, a synthetic view of environmental planning approaches is taken and approachesin action are identified, which characterize the totality of the planning process from problem definition to plan implementation, as well as approachesin the becoming, which may be on the horizon of environmental planning of tomorrow. The suggested future research directions include case studies to verify and detail the presence of the approaches discussed, developing measures of success of a given approach in a given decision setting, and an intertemporal analysis of environmental planning approaches.     

Pollution prevention for sustainable development: the land-use question

The central argument of the paper is that effective pollution prevention can be achieved only by integrated land-use planning which offers the broad framework for co-ordinating technological and non-technological means to achieve sustainable development. The paper first reviews the role of land-use in preventing or contributing to pollution over time, focusing especially on contemporary efforts to promote environmental protection through land-use planning and management. The relationship between land-use, pollution and sustainable development is analysed by examining the most important types of land-use-related problems, discussing their causes and identifying a number of land-use-related constraints to sustainable development. Finally, a land-use planning and policy framework approach to pollution prevention for sustainable development is outlined which emphasizes the need for integrated analysis of pollution problems and adoption of comprehensive approaches to their solution. Scientific, spatial, temporal and policy issues are addressed in the context of the proposed approach.     

The institutional complexity of environmental policy and planning problems: the example of Mediterranean desertification

Environmental policy and planning problems are inherently complex societal problems whose solution requires the deployment of particular combinations of environmental and human resources to achieve sustainable socio-spatial development. Resources are subject, however, to diverse resource regimes. A stumbling block in devising and implementing solutions is the variance between actual resource regimes and those associated with proposed plans and policies as well as the possibility of combining them optimally. The paper explores how the institutional setting—the numerous and diverse actors and resource regimes involved—affects the output and outcomes of the principal stages of the policy and planning process, it offers proposals for institutional change and it suggests future research directions. Desertification control is analyzed as an illustrative example of a domain where institutional complexity is pronounced and crucial for the feasibility and effectiveness of policy and planning interventions.     

Experimental investigation of the quality characteristics of agricultural plastic wastes regarding their recycling and energy recovery potential

A holistic environmentally sound waste management scheme that transforms agricultural plastic waste (APW) streams into labelled guaranteed quality commodities freely traded in open market has been developed by the European research project LabelAgriWaste. The APW quality is defined by the APW material requirements, translated to technical specifications, for recycling or energy recovery. The present work investigates the characteristics of the APW quality and the key factors affecting it from the introduction of the virgin product to the market to the APW stream reaching the disposer. Samples of APW from different countries were traced from their application to the field through their storage phase and transportation to the final destination. The test results showed that the majority of APW retained their mechanical properties after their use preserving a "very good quality" for recycling in terms of degradation. The degree of soil contamination concerning the APW recycling and energy recovery potential fluctuates depending on the agricultural plastic category and application. The chlorine and heavy metal content of the tested APW materials was much lower than the maximum acceptable limits for their potential use in cement industries.