Anna Karlsson

Linköping University | LiU

Anaerobic digestion (AD) is an established process for integrating waste management with renewable energy and nutrient recovery. Much of the research in this field focuses on the utilisation of new substrates, yet their effects on operational aspects such as fluid behaviour and power requirement for mixing are commonly overlooked, despite their imp...

Codigesting fats, oils, and greases with municipal wastewater sludge can greatly improve biomethane recovery at wastewater treatment facilities. Process loading rates of fats, oils, and greases have been previously tested with little knowledge of the digester microbial community structure, and high transient fat loadings have led to long chain fatt...

BACKGROUND Chemical thermo‐mechanical pulp ( CTMP ) mills holds a large biomethane potential in their wastewater. Their broadened market has involved increased bleaching and utilization of different raw materials. Therefore, the main aim of this study was to obtain and maintain a well‐functioning anaerobic digestion ( AD ) process, with a high meth...

Abstract Anaerobic digestion of alkaline kraft ECF (elemental chlorine free) bleaching wastewater in two mesophilic, lab-scale upflow anaerobic sludge bed (UASB) reactors resulted in significantly higher biogas production (250±50 vs. 120±30 NmL g TOCIN(-1)) and reduction of filtered TOC (fTOC) (60±5 vs. 43±6 %) for wastewater from processing of har...

With the final aim of reducing the energy consumption and increase the methane production at Swedish pulp and paper mills, the methane potential of 62 wastewater effluents from 10 processes at seven pulp and/or paper mills (A–G) was determined in anaerobic batch digestion assays. This mapping is a first step towards an energy efficient and more sus...

Several previous studies reported stimulatory effects on biogas process performance after trace metal supplementation. However, the regulation of the bioavailability in relation to chemical speciation, e.g. the role of sulfide is not fully understood. The objective of the present study was to determine the effect of sulfide on chemical speciation a...

The microbial community of 21 full-scale biogas reactors was examined using 454-pyrosequencing of 16S rRNA gene sequences. These reactors included seven (six mesophilic and one thermophilic) digesting sewage sludge (SS) and 14 (ten mesophilic and four thermophilic) co-digesting (CD) various combinations of wastes from slaughterhouses, restaurants a...

The effect of trace element addition on anaerobic digestion of food industry- and household waste was studied using two semi-continuous lab-scale reactors, one (R30+) was supplied with Fe, Co and Ni, while the other (R30) acted as a control. Tracer analysis illustrated that methane production from acetate proceeded through syntrophic acetate oxidat...

The research on suitable alternative clean energy carriers to substitute for the use of fossil fuels is rapidly attracting attention. Biogas is an energy carrier that is considered as a possible alternative in both the developed and the developing world. However, finding suitable energy crops to extract biogas without affecting food security is sti...

The aim of this study was to investigate the effect of trace element supplementation on operation of wheat stillage-fed biogas tank reactors. The stillage used was a residue from bio-ethanol production, containing high levels of sulfate. In biogas production, high sulfate content has been associated with poor process stability in terms of low metha...

Laboratory-scale reactors treating food industry waste were used to investigate the effects of additions of cobalt (Co), nickel/molybdenum/boron (Ni/Mo/B) and selenium/tungsten (Se/W) on the biogas process and the associated microbial community. The highest methane production (predicted value: 860 mL g(-1) VS) was linked to high Se/W concentrations...

The production of H2 from food residues and manure has been optimised using a central composite face-centred (CCF) design. In all 17 assays were run, varying the temperature (20, 37 and ), hydraulic retention time (2, 5 and 8 days) and N2-flow rates (5, 25 or 125 mL/min). Completely stirred tank reactors (2 L) were operated for three hydraulic rete...

The aim of the study was to investigate whether organotin-stabilized poly(vinyl chloride) (PVC) products could contribute to the pool of organotins observed in landfill leachates, and if the possible release could be related to different temperatures and landfill degradation phases. Small-scale anaerobic reactors filled with generic household waste...

Volatile sulfur compounds (VSCs) in biogas originating from a biogas production plant and from a municipal sewage water treatment plant were identified. Samples were taken at various stages of the biogas-producing process, including upgrading the gas to vehicle-fuel quality. Solid-phase microextraction was used for preconcentration of the VSCs, whi...

Different phases of the life cycle of a landfill receiving municipal solid waste (MSW) were monitored in landfill simulation reactors (LSRs) with the aim of investigating the effects of co-disposal of wastes containing organic pollutants (OPs) with MSW. Two LSRs out of four filled with well-characterised MSW received waste materials containing OPs....

Fermentative degradation of phenol was studied using a non-methanogenic, pasteurised enrichment culture containing two morphologically different bacteria. Phenol was fermented to benzoate, acetate and butyrate and their relative occurrence depended on the concentration of hydrogen. Proportionately more benzoate was formed with high initial levels o...

Based on the results of preliminary studies on phenol degradation under mesophilic conditions with a mixed methanogenic culture, we proposed a degradation pathway in which phenol is fermented to acetate: Part of the phenol is reductively transformed to benzoate while the rest is oxidised, forming acetate as end product. According to our calculation...

The potential for biological transformation of 23 xenobiotic compounds by microorganisms in municipal solid waste (MSW) samples from a laboratory scale landfill reactor was studied. In addition the influence of these xenobiotic compounds on methanogenesis was investigated. All R11, 1,1 dichloroethylene, 2,4,6 trichlorophenol, dimethyl phthalate, ph...