Optimization of high phosphorus loaded post-precipitation and separation process
Makarov, Artem (2018)
Makarov, Artem
Kaakkois-Suomen ammattikorkeakoulu
2018
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Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:amk-201802082200
https://urn.fi/URN:NBN:fi:amk-201802082200
Tiivistelmä
This research was aimed to achieve maximum efficiency of post-precipitation and separation process at existing in-situ pilot plant project installed inside Viikinmäki Wastewater Treatment Plant in Helsinki, Finland. The pilot plant is a part of HSY's individual RAVITA program, which is about phosphorus recovery form wastewater. The pilot plant included extra-phosphorus addition to the influent water to simulate the process without chemical or bio-phosphorus removal, followed by coagulation, flocculation and disc filtration stages.
The main purpose of the thesis was to find out which parameters are correlated in the process of chemical post-precipitation and separation and how to adjust them. Every step of the process was analyzed, designed and multiple laboratory- and pilot-scale tests were conducted to obtain formulated goals and positive results. The aims represented themselves optimization of chemical additions, mixing intensities and retention time so that effluent total phosphorus is 0.5 mg/l when the inlet is 3-5 mg/l and BW% (parameter for discfilter operation capacity) of the discfilter is not more than 50–60%. Moreover, the idea to use the sludge formed during the process as coagulation aid (sludge recirculation) has been implemented and researched.
During the current research, optimum chemical addition amounts were determined for different inlet P concentrations, parameters affecting discfilter were observed, sludge recycle enhanced the process of post-precipitation in a positive way and should be considered as useful coagulation aid in this process.
Using the results of this research, it would be possible to estimate the amounts of chemicals to be added in post-precipitation while different inlet phosphorus concentrations and adjust the filtering capacity of the discfilter in the future. The obtained results would be used as a basis for further development and enlargement of the pilot and RAVITA process, since the formed thickened sludge during chemical precipitation has to be treated and it is an attractive source for further nutrient recovery.
The main purpose of the thesis was to find out which parameters are correlated in the process of chemical post-precipitation and separation and how to adjust them. Every step of the process was analyzed, designed and multiple laboratory- and pilot-scale tests were conducted to obtain formulated goals and positive results. The aims represented themselves optimization of chemical additions, mixing intensities and retention time so that effluent total phosphorus is 0.5 mg/l when the inlet is 3-5 mg/l and BW% (parameter for discfilter operation capacity) of the discfilter is not more than 50–60%. Moreover, the idea to use the sludge formed during the process as coagulation aid (sludge recirculation) has been implemented and researched.
During the current research, optimum chemical addition amounts were determined for different inlet P concentrations, parameters affecting discfilter were observed, sludge recycle enhanced the process of post-precipitation in a positive way and should be considered as useful coagulation aid in this process.
Using the results of this research, it would be possible to estimate the amounts of chemicals to be added in post-precipitation while different inlet phosphorus concentrations and adjust the filtering capacity of the discfilter in the future. The obtained results would be used as a basis for further development and enlargement of the pilot and RAVITA process, since the formed thickened sludge during chemical precipitation has to be treated and it is an attractive source for further nutrient recovery.