Composting is a process in which organic matter is mineralized by microorganisms. In January 2005 landfilling of organic waste was prohibited in Sweden. With this prohibition composting has become an important alternative to handle the produced organic Wastes. One problem with continuous small-scale composting is the production of organic acids that will inhibit a further composting process. The aim of these theses was to study what effects temperature and dry matter content had on the production of organics acids, and what effect the organic acids had on the mineralisation of the substrate as well as the stability during storage of the product.

Agricultural soils constitute the base in human food production and soil content of organic matter and plant nutrients together with soil microbial activity are all important parameters for high crop yield of good quality. These parameters are dependant on proper fertilization.Anaerobic digestion of organic Wastes for biogas production generates a liquid residue called biogas residue (BR). It contains organic material and plant nutrients which makes ita potential fertilizer for arable cropping. However, it also contains heavy metals and toxic organic compounds and it is therefore in need of evaluation before usage.Microbial tests were performed aiming to evaluate the agronomic traits of four different BR and to find a viable procedure for evaluating slurry fertilizers. Two experiments where soil respiration and soil potential denitrification activity (PDA) was measured at fertilizer addition were performed.

Syftet med studien är att öka vår förståelse för hur slöserier påverkar ett internt material och produktionsflöde i en producerande verksamhet, för att kunna ge förslag på effektiviseringar av denna process. Studien är utförd på företaget Växjöfabriken Produktions AB som är beläget i Växjö och utför skärande bearbetning på gjutgods. Efter att ha studerat befintliga teorier skapade vi vår teoretiska utgångspunkt med det urval av teorier som vi ansåg vara viktiga för studien. Från dessa genererade vi en analysmodell som sedan låg till grund för det fortsatta arbetet. Analysmodellen gav ett strukturerat arbetssätt för att samla in empirisk fakta från företaget som vi sedan använde för att göra en analyserande jämförelse med vår teoretiska utgångspunkt.

The goal of this master thesis project was to develop computer models of some plausiblepretreatment techniques and to assess the potential benefits/costs of using pretreatment andanaerobic digestion for waste management of organic waste from a system perspective. Forthis purpose a computer program called ORWARE has been used. ORWARE (organic wasteresearch) is a program for making life cycle assessments of waste management. As the mainpart of the project work the ORWARE system has been provided with three new models ofpretreatment techniques. The additions consist of: One model of pretreatment with ultrasound,one model of thermal hydrolysis and one model of a screw press.