<p>Phytoremediation as a way to control and lessen nutrient concentrations in landfill leachate is a cheap and environmentally sustainable method. Accumulated nutrients in the plants can then be removed by harvesting and anaerobically digesting the biomass. This study presents two aquatic plants (L. minor (L.) and P. stratiotes (L.)) and one microalgae species (C. vulgaris (L.)), their capacities for growth and nutrient removal in leachate from Häradsudden landfill, Sweden, are investigated. The biogas potential of the two plants is determined via anaerobic digestion in a batch run, followed by a lab-scale reactor run for L. minor only. Results show that growth in leachate directly from the landfill is not possible for the selected species, but at a leachate dilution of 50% or more. Nutrients are removed in leachates with plants to a higher extent than in leachates without, yet the actual amounts do not differ notably between plant species. L. minor proves a better choice than P. stratiotes despite this as growth is superior for L. minor under the experimental conditions of this study. Considering biogas production, L. minor gives more methane than P. stratiotes according to the results from the batch run. The former is however not suitable for large-scale anaerobic digestion unless as an additional feedstock due to practical cultivation issues.</p>

<p>An analysis of a specific application of anaerobic wastewater treatment at a pulp and board mill, Stora Enso Skoghall, was carried out. A literature study was done and effluent wastewater from CTMP pulp production was analyzed. The analysis consisted of a broad constituent analysis and an anaerobic treatment trial. Results from these test where used to calculate the treatment effectiveness and resulting energy potential at the mill.</p><p>The literature study and constituent analysis showed that toxicity of the water to be treated, due to wood extractives and sulphur content, was of concern. Detoxification chemicals targeting these constituents where used in the anaerobic treatment trial. The trial consisted of a two chamber upflow reactor and aerobic post treatment. The result of the trial is that the water of concern has about 50% anaerobically degradable content. A full scale implementation of anaerobic wastewater treatment would result in a methane production of 3,76 to 7,76 GWh/yr. An application of anaerobic wastewater treatment will also result in electricity savings, in aerated pond, and increase the capacity margin on current sludge handling techniques.</p>

Polychlorinated biphenyls (PCBs) are toxic and persistent anthropogenic contaminants. Concern on their adverse health effects has led to their regulation in air, water and/or soil in addition to sludge. Hence, removal of PCBs in various matrices, including transformer oils (TO) is a priority. This study aims to investigate PCB-118 and Aroclor 1254 toxicity and dechlorination by varying certain critical experimental components including electron donor (sludge or fatty acids), inocula (unacclimated or acclimated culture) and the doses of PCB and TO under anaerobic conditions. Anaerobic toxicity assays (ATA) reactors, lab-scale anaerobic batch digesters and sediment microcosms were used for this purpose. Increase in PCB-118 and TO doses affected anaerobic digester performance by negatively influencing methanogenesis, while favoring dechlorination only with the increase in PCB-118 dose. Up to 22% PCB-118 removal was attained with unacclimated culture. Studies with acclimated cultures showed Grasse River (GR) sediment to be the most active when compared to Fox River and Baltimore Harbor sediments. In GR sediment microcosms, PCB-118 and Aroclor 1254 removal efficiencies decreased when TO was present (1%), while 10% TO inhibited PCB dechlorination. Waste activated sludge was shown to be an effective electron donor, similar to fatty acids. Aroclor 1254 dechlorination was dechlorinated through removal of flanked meta and para chlorines, however, dechlorination pathways appeared to differ according to the presence/absence of TO. No ortho or unflanked chlorines were removed. Molecular tools (qPCR and DHPLC) were used to confirm the presence of active PCB dechlorinators. Dechlorination of PCBs was shown to be growth-linked.

Treatment of waste sludge has become an important issue in recent years around the world. However, the trend of waste sludge treatment has shifted from volume minimization and stabilization to reuse of the sludge and recover the energy potential of it. Therefore, anaerobic treatment of sludge is gaining popularity because of byproduct methane production and high percentage of VSS reduction. Pre-treatment of sludge before anaerobic digestion in order to increase methane production, and ozone pre-treatment in this context, is one such option. Domestic sludge also contains the recently recognized, so called, emerging compounds such as Endocrine Disrupting Compounds (EDCs). Therefore treatment of EDCs in sludge is another challenge in waste sludge treatment since direct discharge of such chemicals may harm the environment by causing gender shifts within the fauna. In this context two hormones (estrone and progesterone), three pharmaceuticals (acetaminophen, carbamazepine and diltiazem) and one plasticizer (benzyl-butyl phthalate) were routinely analyzed in sludge samples which were subjected to treatment during this study. Treatment of EDCs during anaerobic digestion and the effect of ozonation both on the performance of digestion and the treatability of EDCs were investigated in this study. Four 2.5L anaerobic jars were used for anaerobic digestion connected to four 1L plastic graduated cylinders immersed in salt-water to collect the off gas. Anaerobic sludge culture of the reactor and the sludge feed to the reactors were obtained from Ankara Tatlar Wastewater Treatment Plant anaerobic digester and return activated sludge (RAS) line, respectively. One of the anaerobic digesters was used as control (no ozonation) and the others were fed with sludge samples ozonated at three different ozone doses 0.65, 1.33 and 2.65 mg ozone/g biomass. Sludge ages of the reactors were initially set to 25 days and the reactors were fed once every 2 days. The TSS, VSS, total gas volume, COD, pH, CH4 percentage and EDCs were analyzed routinely. In the reactors, operated at 25 days, because of the observation of reduction of TSS, SRT was set to infinity / thus, sludge wastage was terminated. Following the startup it was seen that at 2.65 mg ozone/g biomass dose TSS and VSS did not stay constant in the reactor and dropped sharply in the course of operation, indicating that system was not steady at this SRT. However, upon stoppage of sludge wastage from the reactors, thereby setting SRT to infinity, a steady culture could be maintained in the reactors. Both total gas production and CH4 percentage increased with the increasing doses of ozone with respect to control reactor. For 2.65 mg/g ozonated reactor total gas volume doubled the amount produced in the control reactor. All the EDCs within the scope of this study were analyzed in sludge using ultrasound-aided sequential sludge extraction method twice a week and the results showed that ozonation affected treatment of EDCs for up to 96%. The highest removal rate was obtained with natural hormones. Rates of treatment of pharmaceuticals were the second best.

Treatment of waste sludge has become an important issue in recent years around the world. However, the trend of waste sludge treatment has shifted from volume minimization and stabilization to reuse of the sludge and recover the energy potential of it. Therefore, anaerobic treatment of sludge is gaining popularity because of byproduct methane production and high percentage of VSS reduction. Pre-treatment of sludge before anaerobic digestion in order to increase methane production, and ozone pre-treatment in this context, is one such option. Domestic sludge also contains the recently recognized, so called, emerging compounds such as Endocrine Disrupting Compounds (EDCs). Therefore treatment of EDCs in sludge is another challenge in waste sludge treatment since direct discharge of such chemicals may harm the environment by causing gender shifts within the fauna. In this context two hormones (estrone and progesterone), three pharmaceuticals (acetaminophen, carbamazepine and diltiazem) and one plasticizer (benzyl-butyl phthalate) were routinely analyzed in sludge samples which were subjected to treatment during this study. Treatment of EDCs during anaerobic digestion and the effect of ozonation both on the performance of digestion and the treatability of EDCs were investigated in this study. Four 2.5L anaerobic jars were used for anaerobic digestion connected to four 1L plastic graduated cylinders immersed in salt-water to collect the off gas. Anaerobic sludge culture of the reactor and the sludge feed to the reactors were obtained from Ankara Tatlar Wastewater Treatment Plant anaerobic digester and return activated sludge (RAS) line, respectively. One of the anaerobic digesters was used as control (no ozonation) and the others were fed with sludge samples ozonated at three different ozone doses 0.65, 1.33 and 2.65 mg ozone/g biomass. Sludge ages of the reactors were initially set to 25 days and the reactors were fed once every 2 days. The TSS, VSS, total gas volume, COD, pH, CH4 percentage and EDCs were analyzed routinely. In the reactors, operated at 25 days, because of the observation of reduction of TSS, SRT was set to infinity / thus, sludge wastage was terminated. Following the startup it was seen that at 2.65 mg ozone/g biomass dose TSS and VSS did not stay constant in the reactor and dropped sharply in the course of operation, indicating that system was not steady at this SRT. However, upon stoppage of sludge wastage from the reactors, thereby setting SRT to infinity, a steady culture could be maintained in the reactors. Both total gas production and CH4 percentage increased with the increasing doses of ozone with respect to control reactor. For 2.65 mg/g ozonated reactor total gas volume doubled the amount produced in the control reactor. All the EDCs within the scope of this study were analyzed in sludge using ultrasound-aided sequential sludge extraction method twice a week and the results showed that ozonation affected treatment of EDCs for up to 96%. The highest removal rate was obtained with natural hormones. Rates of treatment of pharmaceuticals were the second best.

Scum is an integral component of solids management in MWWTP and is composed of fats, oils, grease and other entrained floatable materials that are collected during primary clarification. Lab scale BMP tests showed the addition of 14.5 g VS/L of scum exhibited the greatest increase in biogas production of 1.6 times per g VS added compared to the control, while a higher additional scum loading of 33.7 g VS/L reduced the biogas yield to 32% of the control reactor. Lab scale semi-continuous digestion measured the effects of scum loading and temperature of pretreatment in the scum concentrator. At 15 d and 20 d HRTs the greatest observed improvement in biogas was achieved by adding 3% scum by volume and pretreating the scum at 70°C in a scum concentrator with respective improvements of 24% and 16%.

Anaerobic digestion of excess biological wastewater treatment sludge (WAS) from pulp mills has the potential to reduce disposal costs and to generate energy through biogas production. The organic matter in WAS is highly structured, which normally hinders biogas production. This study investigated three methods of pretreating WAS from two different pulp mills before anaerobic digestion to improve biogas yield and production rate. The three pretreatment methods tested were: i) thermal pretreatment at 170oC, ii) caustic pretreatment at 140oC and pH 12, and iii) sonication at 20 kHz and 1 W/mL. Thermal pretreatment proved to be the most effective, increasing biogas yield by 280% and 50% and increasing production rates 300-fold and 10-fold for the two samples, respectively. Caustic pretreatment showed similar results, but resulted in the formation of soluble non-biodegradable compounds. Sonication was the least effective pretreatment and did not substantially increase biogas yield, but increased biogas production rate.

The development and patenting of a new technology for the anaerobic digestion of solid waste is described. The design basis is explained and justified by extensive reference to the literature. The technology was specifically designed to be versatile, robust and affordable and is directly derived from other proven processes for organic waste management. The ways in which environmental regulations directly affect the development and commercialization of organic waste processing technologies are described. The great differences in regulations between Europe and North America are analyzed to explain why anaerobic digestion is common in Europe and rare in North America and why this is the result of waste management economics which are driven by these regulations. The new technology is shown to be competitive in the Province of Ontario in particular and North America in general; a detailed financial analysis and comparison with European technologies is provided in support of this conclusion.

To improve biogas production from lignocellulosics, methanogenic microbial enrichments were prepared from moose rumen fluid, beaver droppings, and internal circulation (IC) reactor granules amended with cellulose, pine needles, lignosulphonate, tannic acid, and poplar hydrolysate. Tannic acid delayed methanogenesis compared to cellulose only enrichments, both by reducing initial rates (up to 50% in beaver dropping cultures) and increasing lag times (up to 50 days in moose rumen cultures). Biogas yields from poplar hydrolysate were 56 % by beaver droppings, 51% % by IC granules, and 31 % by moose rumen enrichments. Bacterial community profiles, determined via denaturing gradient gel electrophoresis (DGGE) showed divergent populations between enrichments. Enrichment on pine needles or poplar hydrolysate promoted bioconversion of post extraction wash (PEW), and beaver dropping enrichments fed pine needles equaled the yield (about 23%) from IC granules. Together, the DGGE and PEW results provide evidence of acclimatization to previously recalcitrant feeds.

The development and patenting of a new technology for the anaerobic digestion of solid waste is described. The design basis is explained and justified by extensive reference to the literature. The technology was specifically designed to be versatile, robust and affordable and is directly derived from other proven processes for organic waste management. The ways in which environmental regulations directly affect the development and commercialization of organic waste processing technologies are described. The great differences in regulations between Europe and North America are analyzed to explain why anaerobic digestion is common in Europe and rare in North America and why this is the result of waste management economics which are driven by these regulations. The new technology is shown to be competitive in the Province of Ontario in particular and North America in general; a detailed financial analysis and comparison with European technologies is provided in support of this conclusion.