Dissertation/ Thesis

Opportunities for increased nutrient recovery at centralised wastewater treatment plants through urine separation

التفاصيل البيبلوغرافية
العنوان: Opportunities for increased nutrient recovery at centralised wastewater treatment plants through urine separation
Alternate Title: Möjligheter till ökad näringsåtervinning vid centraliserade avloppsreningsverk genom urinsortering
المؤلفون: Gustavsson, Hanna
بيانات النشر: Uppsala universitet, Institutionen för geovetenskaper, 2021.
سنة النشر: 2021
المجموعة: DiVA Archive at Upsalla University
مصطلحات موضوعية: Nutrient recovery, urine separation, magnesium ammonium phospahte, MAP, ammonium sulphate, AMS, and DHI's WEST, Water Engineering, Vattenteknik, Water Treatment, Vattenbehandling
الوصف: Municipal wastewater contains a significant amount of nutrients such as phosphorus (P) and nitrogen (N). Therefore have the interest of recovering these nutrients at wastewater treatment plants (WWTP) increased. Nutrient recovery would generate revenue for the WWTP, as it is possible to sell the products as fertiliser. Today, there are several techniques on the market to recover P as magnesium ammonium phosphate (MAP) and N as ammonium sulphate (AMS). Urine is the fraction contributing with the highest concentration of nutrients. Techniques to separate urine from the rest of the wastewater have been developed. These techniques enable the possibility to recover nutrients from the urine fraction separately; this is beneficial since the nutrient concentration would be higher. The purpose with this study was to examine the possibility for increased nutrient recovery at centralised WWTPs through urine separation. Different techniques for nutrient recovery were compared by their recovery efficiency, chemical demand, and hydraulic retention time (HRT). A WWTP with enhanced biological P removal was modelled with Danish Hydraulic Institute’s (DHI) software WEST. Eight scenarios, with different percentage of the population equivalents using urine separation techniques, were simulated. The P recovery was calculated from phosphate (PO4) in the hydrolysed excess sludge and the separated urine. The N recovery was calculated from the ammonium (NH4) in the supernatant from the anaerobe digester. The theoretical biogas production was also calculated, from the modelled sludge. The comparison of P recovery techniques showed no substantial differences in their recovery efficiency, chemical demand, and HRT. The comparison of N recovery techniques showed three techniques with a higher efficiency than the other methods. Ekobalans Fenix AB, CMI Europe Environment, and Organics developed these techniques. To determine which method to use, requests for proposal from different providers are recommended. As the urine separation increased, the influent P and N load decreased. When the urine separation increased and the operational parameters were kept constant, the effluent concentration of P and N decreased. The ratio of total Kjeldahl nitrogen (TKN) and total nitrogen (TN) however increased as the urine separation increased. The total MAP production calculated from the modelled hydrolysis showed that the production increased as the urine separation increased. On the other hand, the total MAP production from calculated hydrolysis showed a decrease in production as the urine separation increased. The difference in these results could be because of the performance of the modelled hydrolysis was better with a smaller nutrient load, resulting in a larger release of PO4 as the urine separation increased. The total AMS production increased as the urine separation increased. This, due to the increase of the TKN:TN ratio. The biogas production was not substantially affected by the increased urine separation.
Original Identifier: oai:DiVA.org:uu-440801
نوع الوثيقة: Text
وصف الملف: application/pdf
اللغة: English
Relation: UPTEC W, 1401-5765 ; 21016
الاتاحة: http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-440801
Rights: info:eu-repo/semantics/openAccess
رقم الانضمام: edsndl.UPSALLA1.oai.DiVA.org.uu.440801
قاعدة البيانات: Networked Digital Library of Theses & Dissertations