Vpliv dejavnikov na spreminjanje pH vrednosti v procesu anaerobne digestije

diplomsko delo visokošolskega strokovnega študijskega programa I. stopnje

Barbara Smonkar (Author), Lidija Čuček (Mentor), Darja Pečar (Co-mentor)

Abstract

Učinkovitost anaerobne digestije je odvisna od nekaterih ključnih parametrov. Zelo pomembno je, da ustvarimo optimalne pogoje za anaerobne mikroorganizme. Vrednost pH znatno vpliva na rast metanogenih mikroorganizmov in na razkroj nekaterih komponent, pomembnih za proces anaerobne digestije. S sprotnim merjenjem pH-ja lahko s pomočjo različnih dejavnikov dosežemo optimalne pogoje in s tem večjo proizvodnjo bioplina. V diplomskem delu ugotavljamo vplive različnih dejavnikov na spreminjanje pH vrednosti v procesu anaerobne digestije, kot so različni substrati in njihova razmerja, dodatek pufra, dodatek apna ali sode bikarbone in temperaturni šok. Za substrate smo uporabili blato čistilnih naprav, perutninski gnoj s steljo, koruzno silažo in glicerol. Spremljali smo pH vrednost v procesu ter ugotavljali pri katerih razmerjih surovin se pH vrednost nahaja izven optimalnega območja. S pomočjo eksperimentov smo skušali doseči in vzdrževati optimalen pH ter preprečiti zakisanost. To smo storili z dodatkom pufra na začetku poizkusa ter z dodatkoma apna oz. sode bikarbone, ko je vrednost pH padla pod 6,5. S tem smo dosegli, da je bil pH v optimalnem območju in posledično smo dobili izboljšano proizvodnjo bioplina. Po 30 dneh se je najbolje izkazala soda bikarbona, s katero smo dosegli več kot 6-kratno proizvodnjo bioplina glede na mešanico brez dodane sode bikarbone. Tudi dodatek apna je izboljšal proizvodnjo bioplina, vendar je bila proizvodnja bioplina precej manjša v primerjavi z mešanico, kjer smo dodali sodo bikarbono. Na koncu procesa anaerobne digestije (po 62 dneh) razlika med prostorninami bioplina teh mešanic ni več vidna. Prostornina bioplina je skoraj pri vseh mešanicah enaka in povprečno znaša 1616 mL.

Keywords

anaerobna digestija;pH vrednost;vpliv dejavnikov;proizvodnja bioplina;diplomske naloge;

Data

Language:	Slovenian
Year of publishing:	2017
Typology:	2.11 - Undergraduate Thesis
Organization:	UM FKKT - Faculty of Chemistry and Chemical Engineering
Publisher:	[B. Smonkar]
UDC:	628.336.5:66.098.4(043.2)
COBISS:	21063446
Views:	1107
Downloads:	33
Average score:	0 (0 votes)
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Other data

Secondary language:	English
Secondary title:	Influence of factors affecting pH in the process of anaerobic digestion
Secondary abstract:	The efficiency of anaerobic digestion depends on certain key parameters. It is of the utmost importance to create optimal conditions for anaerobic microorganisms. The pH value significantly influences the growth of methanogenic microorganisms and the decomposition of some components that are important for the process of anaerobic digestion. By frequently measuring the pH value we can, by considering the effects of various influential factors, achieve optimal conditions and therefore a greater biogas production. In the diploma thesis, the effects of various factors on the change of pH values in the process of anaerobic digestion have been determined, such as different substrates and their ratios, addition of buffer, lime or sodium bicarbonate, and temperature shock. Sewage sludge from wastewater treatment plants, poultry manure, corn silage and crude glycerol were used as substrates. The pH value was monitored during the process, and was found for which ratios of substrates the pH value lay outside the optimal range. Experiments were conducted to try to achieve and maintain the optimal pH value to prevent acidification. This was performed with the addition of buffer at the beginning of the experiment and with the addition of lime or sodium bicarbonate when the pH value dropped below 6.5. Therefore, the pH value was in an optimal range and consequently an increased biogas production was achieved. After 30 days, sodium bicarbonate proved to be the most efficient, with which the biogas production was more than 6 times greater compared to the mixture without sodium bicarbonate. The addition of lime increased biogas production as well, but it was still significantly lower compared to the mixture with added sodium bicarbonate. At the end of anaerobic digestion (after 62 days), the difference between biogas production of these mixtures was no longer visible. The volume of biogas was the same in almost all mixtures and amounted to 1616 mL in average.
Secondary keywords:	anaerobic digestion;pH value;influence of factors;biogas production;
URN:	URN:SI:UM:
Type (COBISS):	Bachelor thesis/paper
Embargo end date (OpenAIRE):	2020-11-07
Thesis comment:	Univ. v Mariboru, Fak. za kemijo in kemijsko tehnologijo
Pages:	X, 49 str.
ID:	10859900