Decadal oscillations of the aquatic chemistry of river waters in Latvia

Abstract. 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 se…

Refuse Derived Fuel Gasification Possibilities in Small Scale Units

Fossil fuels use reduction and waste recycling are two great challenges facing our society nowadays. A concept intended to solve both problems is Waste-to-Energy (WtE) approach (Brunner and Rechberger in Waste Manag 37: 3–12, 2015). The routes to the energy recovery can be grouped as thermo-chemical and biochemical approaches and the selection of the WtE technologies also depends on the waste composition. Waste sources can be industrial and agricultural production and urban regions but growing attention is paid to municipal solid waste in OECD countries (Hoornweg and Bhada-Tata in What a waste: a global review of solid waste management. World Bank, Washington, DC 2012) consisting dominantly…

Thermal decomposition study of major refuse derived fuel components

Abstract Refuse Derived Fuel (RDF) composed on biomass, paper, textiles, wood, synthetic polymers and other combustible materials is an alternative energy resource to implement Waste-to-Energy strategy. The aim of this study is to investigate the thermal decomposition characteristics of materials forming RDF by thermogravimetric analysis. Thermogravimetric (TG) analysis of RDF components demonstrates major differences in processes behind the thermal decomposition processes of waste components. Biomass decomposition can be divided into two distinct stages for wood, cotton, cotton wool and other biomass samples whereas three distinct stages can be distinguished for cardboard and paper samples…

Sorption of Hydrocarbons on Peat, and Possibilities for Using Peat-Based Oil Sorbent for Treatment of Polluted Areas

The growing use and transport of crude oil and oil products has led to an increasing amount of spillages of various scales. In the event of an oil spill, it is important to stop the spill from spreading and to clean up the polluted environment. One of the possible ways of treating the polluted areas is the use of oil sorbents. The sorbents used for collecting oil in case of oil spills are mostly synthetic, which limits the possibilities of their disposal. The aim of our study is to investigate the possible use of peat and its modification products for oil and other hydrocarbon sorption. Peat is a prospective material for oil sorption because it has such advantages as low cost, biodegradabil…

Thermogravimetric analysis as express tool for quality assessment of refuse derived fuels used for pyro-gasification

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 a 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 Est…

Evolution of pyrolysis and gasification as waste to energy tools for low carbon economy

Development of a new peat-based oil sorbent using peat pyrolysis

The growing use and transport of crude oil and oil products has led to increasing numbers of oil spillages of various scales. Oil sorbents have been extensively used for remediation of the consequences of such accidents. The aim of this study is to investigate the possible use of peat and its thermal treatment products for oil sorption. Peat as an oil sorbent has poor buoyancy characteristics, relatively low oil sorption capacity and low hydrophobicity. However, thermal treatment (low-temperature pyrolysis and synthesis of peat-based activated coal) helps to significantly improve its sorptive characteristics. Peat is a potential material for oil sorption because it has such advantages as lo…