For decades, significant work has been conducted regarding plastic waste by dealing with rejected materials in waste masses through their accumulation, sorting and recycling. Important political and technical challenges are involved, especially with respect to landfilled waste. Plastic is popular and, notwithstanding decrease policies, it will remain a material widely used in most economic sectors. However, questions of plastic waste recycling in the contemporary world cannot be solved without knowing the material, which can be achieved by careful sampling, analysis and quantification. Plastic is heterogeneous, but usually all plastic waste is jointly handled for recycling and incineration. Separation before processing waste through the analytical approach must be applied. Modern landfill mining and site clean-up projects in contemporary waste management systems require comprehensive material studies ranging from the macro-characterization of waste masses to a more detailed analysis of hazardous constituents and properties from an energy calorific standpoint—where, among other methods, thermogravimetric research coupled with life cycle assessment (LCA) and economic assessment is highly welcomed.

The development of pyro gasification technologies makes necessary the development of new express analytical methods, that are able to deal with the variability of feedstock and problems arising from it. Thermogravimetric proximate analysis of refuse derived fuels is a very fast, cheap and simple method for the determination of proximate and fractional composition. Development of this analytical approach may result in very cost-effective method to describe wholesome composition and characteristics of feedstock used for pyrolysis and gasification processes in real time. The aim of this study was the development of such analytical method. Refuse derived fuel samples produced in Latvia and Estonia analysed during this study with thermogravimetric proximate analysis and standard methods. Equations for determination of gross calorific value and elemental composition from thermogravimetric proximate analysis were developed. Furthermore, results show that also signals pointing to excessive proportion of chlorine and fluorine can be obtained, using this method. The results obtained during this study can help to develop the automatic feedstock quality control systems for modern thermal processing technologies used in waste management.

Water quality changes of surface waters can be used to assess human impact intensity, but of importance is to consider also impacts of climate change/variability and naturally occurring changes of environmental quality. In Latvia, during the recent decades a major reduction of anthropogenic pressure has happened due to restructuring of economy and industrial production, resulting in major decrease of loading of many groups of pollutants. However, trends and driving factors for other groups of substances have not been much studied. Long term (1980–2012) results of hydrochemical monitoring, performed in rivers of Latvia, are analysed during this study in connection with long-term sets of hydrological and heliophysical data, using standard statistical approaches. Our results indicate that variation of some hydrochemical values, for example COD and total Fe, show clearly visible decadal oscillated character, while variation of some other values, for example phosphate P and total P, show some individual characteristics of decadal oscillations. These results indicate the presence of a large scale, geochemical and geophysical significant process: multiannual pulse of catchment, driven by variation of solar irradiance through complex interactions between global atmospheric circulation, groundwater and surface waterbodies. The process described in our study is significant from a geochemical point of view and must be taken into account in prediction of water quality and quantity. Impacts of natural processes should be considered in the planning of environmental policy.

This article examines the emergence and transformation of waste-based artificial reefs in southern Florida during the late 1960s and 1970s. It traces how early community-led efforts to restore declining fisheries, grounded in local ecological knowledge and practical experience, developed into large-scale projects that used discarded tyres and other waste materials. Drawing on newspaper accounts, scientific publications and corporate archival materials, the study shows how businesses such as Goodyear and the Deltona Corporation appropriated reef-building to address their own waste-management, reputational and regulatory concerns. As corporate actors increasingly shaped the practice, reef-building shifted from grassroots ecological restoration to a means of disposing of solid waste at sea, publicly framed as environmental improvement. The long-term consequences – including the instability of tyre reefs, widespread ecological damage and costly public clean-up operations – reveal how restoration rhetoric obscured material risks and redistributed responsibility to state agencies and volunteers. By analysing how practical, regulatory and promotional logics became intertwined, the article demonstrates how environmental interventions can be transformed when they begin to serve the interests of larger actors, and highlights the need to scrutinise the processes through which environmental practices acquire legitimacy.