Discovering the optimum bacterial environment in the activated sludge purification of cardboard industry’s wastewater
Heydarian, Ramtin (2022)
Diplomityö
2022
School of Energy Systems, Ympäristötekniikka
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Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi-fe2022102563282
https://urn.fi/URN:NBN:fi-fe2022102563282
Tiivistelmä
Activated sludge is the beating heart of the biological wastewater treatment plant. Regarding increment in incoming BOD and COD load, it was necessary to find the desirable environmental condition for biological life to make sure effluent obtains components within the permitted value.
This work has been done in Metsä Board packaging and folding boxboard mill’s industrial wastewater treatment plant, Simpele, Finland. It was found that pH value equal to 6.75 is the most favourable value suitable for bacteria to thrive and temperature in 33 °C in order to achieve moderated amount of filaments, worms and amoeba in parallel with maintaining optimum portions of rotifers, cilia and flagella.
It was tried to evaluate the influent to be treated from the mill’s discharge to the discharge point to the water body or sludge to be treated and be used in power plant for heat recovery. It was discovered during the maintenance, bacteria become weaker and their quantity dramatically reduces as nutrient dosing ceases, and after resuming the production, bacterial life returns to the stable situation due to proper dosing and observations.
This work has been done in Metsä Board packaging and folding boxboard mill’s industrial wastewater treatment plant, Simpele, Finland. It was found that pH value equal to 6.75 is the most favourable value suitable for bacteria to thrive and temperature in 33 °C in order to achieve moderated amount of filaments, worms and amoeba in parallel with maintaining optimum portions of rotifers, cilia and flagella.
It was tried to evaluate the influent to be treated from the mill’s discharge to the discharge point to the water body or sludge to be treated and be used in power plant for heat recovery. It was discovered during the maintenance, bacteria become weaker and their quantity dramatically reduces as nutrient dosing ceases, and after resuming the production, bacterial life returns to the stable situation due to proper dosing and observations.