Anna Grala

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%.

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.

Acquisition feasibility and methane fermentation effectiveness of biomass of microalgae occurring in eutrophicated aquifers on the example of the Vistula Lagoon

ABSTRACT This study was aimed at establishing the feasibility of microalgae biomass acquisition from waters of the Vistula Lagoon with the use of an installation operating in the fractional–technical scale, and at determining the effectiveness of biogas production from the acquired substrate. Depending on the technological solution of the concentration process, the degree of aquatic biomass hydration ranged from 99.6 to 97.90%. The quantity of biogas produced during methane fermentation fitted within the range of 243.9 to 395.2 dm3/kg d.m.. The values achieved were found to depend directly on the concentration of organic matter in the acquired water biomass and on system’s loading with a feedstock of organic compounds. The content of methane in a gaseous mixture ranged from 41.4 to 61.9%. The biomass produced was predominated by taxa belonging to Cyanoprokaryota, Bacillarophyceae, and Chlorophyta.

Effect of the Application of Advanced Oxidation Technology on the Effectiveness of Anaerobic Treatment of Wastewaters with a High Concentration of Formaldehyde

Abstract The objective of this study was to determine the effect of advanced oxidation process with the use of Fenton’s reaction on the effectiveness of anaerobic treatment of wastewaters originating from the wood industry that were characterized by a high concentration of formaldehyde. Experiments were established to analyze changes in COD content and in the concentration of formaldehyde in treated wastewaters, additional analyses were carried out to assay quantitative and qualitative changes in the biogas produced. The first stage of the experiment involved analyses of the effectiveness of the tested wastewaters treatment only in the process of methane fermentation. At the second stage of the experiment, the biological process was preceded by chemical pre-treatment of wastewaters with Fenton’s reagent. The conducted study proved that the investigated variants of chemical pre-treatment of wastewaters had a significant effect on increasing the total biogas production. In contrast, no significant effect of the applied technology was demonstrated on changes in the concentration of the analyzed contaminants in the treated wastewaters. Streszczenie Celem prowadzonych badań było określenie wpływu procesu pogłębionego utleniania z zastosowaniem reakcji Fentona na efektywność beztlenowego oczyszczania ścieków pochodzących z przemysłu drzewnego, które charakteryzowały się wysoką koncentracją formaldehydu. W eksperymentach analizowano zmiany wartości ChZT oraz koncentracji formaldehydu w ściekach oczyszczonych, badano również zmiany ilości i składu jakościowego powstającego biogazu. W pierwszym etapie doświadczenia analizowano efektywność oczyszczania testowanych ścieków jedynie w procesie fermentacji metanowej. W drugiej części eksperymentu proces biologiczny poprzedzono wstępnym oczyszczaniem chemicznym z zastosowaniem odczynnika Fentona. Przeprowadzone badania udowodniły, iż testowane warianty wstępnej chemicznej obróbki ścieków wpłynęły istotnie na zwiększenie całkowitej ilości produkowanego biogazu. Nie stwierdzono natomiast znaczącego wpływu zastosowanej technologii na zmiany koncentracji analizowanych wskaźników zanieczyszczeń w ściekach oczyszczonych.