Marcin Dębowski

Impact of temperature, microwave radiation and organic loading rate on methanogenic community and biogas production during fermentation of dairy wastewater.

This study analyzed dairy wastewater fermentation in convection- and microwave-heated hybrid reactors at loadings of 1 and 2 kg COD/(m3 d) and temperatures of 35 and 55 °C. The biomass was investigated at a molecular level to determine the links between the operational parameters of anaerobic digestion and methanogenic Archaea structure. The highest production of biogas with methane content of ca. 67% was noted in the mesophilic microwave-heated reactors. The production of methane-rich biogas and the overall diversity of Archaea was determined by Methanosarcinaceae presence. The temperature and the application of microwaves were the main factors explaining the variations in the methanogen community. At 35 °C, the microwave heating stimulated the growth of highly diverse methanogen assemblages, promoting Methanosarcina barkeri presence and excluding Methanosarcina harudinacea from the biomass. A temperature increase to 55 °C lowered Methanosarcinaceae abundance and induced a replacement of Methanoculleus palmolei by Methanosarcina thermophila.

Application of microwave radiation to biofilm heating during wastewater treatment in trickling filters.

The purpose of this study was to demonstrate the potential for improving wastewater treatment by the application of microwave radiation (MW) compared to convective heating (CH) of trickling filters. Microwaves were delivered to the biofilm in a continuous and intermittent way to obtain temperatures of 20, 25, 35 and 40 °C. Although there was no effect of MW on organic removal, the observed yield coefficient was lower during the continuous MW supply compared to the periodic dosage and CH. The presence of organic compounds in the influent and continuous biofilm exposure to MW resulted in ca. 10% higher efficiency and ca. 20% higher rate of nitrification compared to intermittent MW dosage and CH. Independent of the method of reactor heating, the absence of organic carbon in the influent induced a significant increase in ammonium oxidation efficiency at 20-35 °C. Despite the aerobic conditions in trickling filters, nitrogen loss was observed.

The Possibility of Using Macroalgae Biomass from Natural Reservoirs as a Substrate in the Methane Fermentation Process

The objective of this study was to determine the possibility of applying macroalgae biomass originating from Bay of Puck, Poland, as a substrate in the methane fermentation process and to verify the impact of taxonomic structure and other physicochemical traits of the analyzed biomass on the technological effectiveness of the fermentation process. The efficiency of methane fermentation was determined using respirometric kits. In all periods of the vegetative season, the structure of macrophytobenthos was predominated by brown algae of the family Ectocarpaceae, namely Pilayella litoralis and Ectocarpus sp. The production of biogas fitted within a narrow range of 266.53 ± 16.43 cm3/g o.d.m. during fermentation of algae harvested in September and 285.71 ± 11.35 cm3/g o.d.m. in that from August. The percentage content of methane in biogas ranged from 57.28 ± 1.75% to 59.22 ± 2.84%. Regardless of macroalgae biomass harvest period, the postfermented sludge was characterized by similar values of the analyzed parameters.

Effect of magneto-active filling on the effectiveness of methane fermentation of dairy wastewaters

AbstractThe goal of this study was to determine the effectiveness of methane fermentation of dairy wastewaters in terms of the volume and qualitative composition of biogas produced in an anaerobic reactor with magneto-active filling (MAF) mounted in the zone of hydrolysis and acidogenesis. Experiments were conducted in the fractional-technical scale in a vertical fermentation reactor with a labyrinth flow. Synthetic dairy wastewaters prepared based on milk powder were used as a substrate. The analyzed filling was made of plastic covered with iron and copper powders and was additionally equipped in fluid magnetizers (FM) in the form of neodymium magnets. The study demonstrated that MAF incorporation into the technological system significantly improved effectiveness of biogas production, increased methane concentration and lowered content of hydrogen sulfide in gaseous metabolites of fermentative bacteria. A significant increase was also observed in the effectiveness of COD removal from dairy wastewaters. R...

Respirometric studies on the effectiveness of biogas production from wastewaters originating from dairy, sugar and tanning industry

The objective of the present study was to determine the effectiveness of biogas production during methane fermentation of wastewaters originating from the dairy, tanning and sugar industries, by means of respirometric measurements conducted at a temperature of 35°C. Experiments were carried out with the use of model tanks of volume 0.5 dm3. A high production yield of biogas, with methane content exceeding 60%, was achieved in the case of the anaerobic treatment of wastewaters from the dairy and sugar industries. A significantly lower effect was observed in the case of tanning wastewaters. The effectiveness of the fermentation process decreased with increasing loading of the tanks with a feedstock of organic compounds. By loading a model tank with this feedstock, the effectiveness of treatment ranged from 62.8% to 71.4% residual chemical oxygen demand for dairy wastewaters and from 57.9% to 64.1% for sugar industry wastewaters. The efficiency of organic compound removal from tanning wastewaters was below 50%, regardless of the method applied.

Efficiency of the Methane Fermentation Process of Macroalgae Biomass Originating from Puck Bay / Wydajność Procesu Fermentacji Metanowej Biomasy Makroglonów Pochodzących Z Zatoki Puckiej

Abstract The aim of the conducted research was to determine the possibilities of using the biomass of macroalgae obtained from Puck Bay during May-September season in biogas production process. Model respirometry chambers were used to determine the amount of produced biogas and examine its quality composition. Depending on the month in which the algal biomass was obtained, the experiments were divided into five stages. In each stage, the effectiveness of the biogas production process was tested for the applied loads in model fermentation chambers in the range from 1.0 kg DOM/m3 · d to 3.0 kg DOM/m3 · d. During the experiments it was found that the efficiency of biogas production varied from 205 dm3/kg DOM to 407 dm3/kg DOM depending on the month of the vegetation season and the applied organic matter load in the chamber. Methane content was very high and ranged from 63% to 74%. Celem prowadzonych badań było określenie możliwości wykorzystania biomasy makroglonów pozyskiwanych z Zatoki Puckiej w okresie od maja do września w procesie wytwarzania biogazu. Do określenia ilości wytwarzanego biogazu oraz zbadania jego składu jakościowego wykorzystano modelowe komory respirometryczne. W zależności od miesiąca, w którym pozyskiwano biomasę glonową eksperymenty podzielono na pięć etapów. W każdym z etapów testowano efektywność procesu biogazowania w zakresie stosowanych obciążeń modelowych komór fermentacyjnych w zakresie od 1,0 kg s.m.o/m3 · d do 3,0 kg s.m.o./m3 · d. W trakcie eksperymentów stwierdzono, iż wydajność wytwarzania biogazu kształtowała się w zakresie od 205 dm3/kg s.m.o. do 407 dm3/kg s.m.o. w zależności od miesiąca okresu wegetacyjnego oraz stosowanego obciążenia komory ładunkiem substancji organicznej. Zawartość metanu była bardzo wysoka i mieściła się w granicach od 63% do 74%.

Effectiveness of dairy wastewater treatment in a bioreactor based on the integrated technology of activated sludge and hydrophyte system

The aim of this study was to determine the effectiveness of dairy wastewater treatment in the integrated technology based on the simultaneous use of the activated sludge method (AS) and a hydrophyte system (HS) (AS–HS), in this case, common reed (Phragmites australis) or common cattail (Typha latifolia). Experiments were conducted in an innovative reactor exploited in the fractional-technical scale at the loads of 0.05 mg BOD5/mg.d.m. d (biochemical oxygen demand) and 0.10 mg BOD5/mg.d.m d. The AS–HS enabled improving the removal effectiveness of biogenes characterized by concentrations of Ntot., N-NH4 and Ptot.. In contrast, the integrated system had no significant reducing effect either on concentrations of organic compounds characterized by BOD5 and chemical oxygen demand parameters or on the structure of AS in the sequencing batch-type reactors.

Effect of constant magnetic field on anaerobic digestion of algal biomass

ABSTRACT The aim of the study was to determine the impact of the constant magnetic field (CMF) application on the effectiveness of anaerobic digestion of algal biomass. The highest yield of biogas in the range of 448.9 L/kg volatile solids (VS) to 456.6 L/kg VS was observed in the variants, in which the retention time in the CMF-exposed area ranged from 144 to 216 min/d. Under these conditions, the concentration of methane in the biogas was nearly 65.0%. The increase in the contact time of the fermentation medium with the CMF-exposed area had a significant impact of reducing the effectiveness of anaerobic digestion. The lowest biodegradation was observed when the retention time was 432 min/d. Under such condition, 281.1 L of biogas/kg VS with methane content of 41.8% was obtained. A correlation between the time of exposure to CMF and the values of parameters characterizing the methane production was found.

The effect of pressure and temperature pretreatment on the biogas output from algal biomass

This paper presents data on methane fermentation of algal biomass containing Chlorella sp. and Scenedesmus sp. The biomass was obtained from closed-culture photobioreactors. Before the process, the algae were subjected to low temperature and pressure pretreatment for 0.0, 0.5, 1.0 and 2.0 h. The prepared biomass was subjected to mesophilic methane fermentation. The amount and composition of the biogas formed in the process were determined. The amount of biogas produced was larger when the biomass was subjected to thermal preprocessing. The proportion of methane in the gas also increased. Extending the heating time beyond 1.0 h did not significantly improve the biogassing effects.

Influence of static magnetic field on sludge properties

Abstract The study investigated the influence of static magnetic field on sedimentation of activated sludge, coagulation efficiency in the bioreactors and dewaterability of the sludge. The sedimentation was improved when magnetizers were applied on the bioreactor and on the settling tank. The application of magnetizers only on the settling tank decreased the sedimentation properties of the sludge. The filamentous bacteria Type 0092 dominated in both bioreactors, but the significant differences were observed in its length. No effect of the static magnetic field on coagulation with the utilization of iron-based coagulant was observed. However, the static magnetic field enhanced coagulation with the utilization of aluminum-based coagulant. The results suggest that increased sedimentation of colloids and activated sludge, can in practice mean a reduction in the size of the necessary equipment for sedimentation with an unchanged efficiency of the process. Moreover, static magnetic field significantly reduced the COD concentration in filtrate and shorted capillary suction time during the dewaterability of waste activated sludge.