| Title | Thermal energy recovery from a sequencing batch biofilter granular reactor (SBBGR) on a pilot scale: Evaluation of the effects of energy extraction on the depuration process, process effectiveness, and results scalability |
| Abstract | Urban wastewater is a valuable source of clean energy available for both building conditioning and hot sanitary water production, thus reducing primary energy demand and greenhouse gas emissions. In the present study, the integration of a highly efficient solar-assisted fully off-the-grid water-source heat pump (SHP) with a sequencing batch biofilter granular reactor (SBBGR) is tested on a pilot scale for recovering and reusing thermal energy generated during the depuration process. The prototype was designed to simulate wastewater production (240 L/d), domestic hot water (DHW) (152 L/d at 40 °C), and space heating (20-25 °C) energy demand for a one-person equivalent. Three set temperatures for heat extraction from the SBBGR were tested: 20, 14, and 10 °C. Heat extraction had limited effects on the average SBBGR performances. The SBBGR ensured a removal efficiency close to 90% for total suspended solids (TSS), chemical oxygen demand (COD), and ammonia, whereas a decrease in total nitrogen (TN) removal efficiency, namely from 75% to 71%, was observed with the operating temperature decrease. Energy recovery data suggested that the energy extracted from the SBBGR might cover the energy demand for DHW production or space heating from April to October. Thus, the collected energy data was modeled with the following purposes: highlighting the key parameters for optimizing energy recovery, quantifying the share of recoverable energy derived the microbial metabolism, and supporting or rejecting the scalability of the results. The model outcomes confirmed that the temperature difference between the sewage and heat extraction set point temperatures was the key parameter for energy recovery and succeeded in estimating the contribution of microbial metabolisms (i.e. about 3.2 kWh/m3 × d). However, the estimation of the full-scale recoverable energy was partially biased by the impact of the environmental conditions on the pilot. |
| Source | Energy conversion and management |
| Keywords | Thermal energy recoverySewage treatmentSolar powered water source heat pumpLinear modelTie series |
| Journal | Energy conversion and management |
| Editor | Pergamon., New York, Regno Unito |
| Year | 2020 |
| Type | Articolo in rivista |
| DOI | 10.1016/j.enconman.2020.113582 |
| Authors | Barca Emanuele; De Sanctis Marco; Altieri Valerio Guido; Di Iaconi Claudio. |
| Text | 439431 2020 10.1016/j.enconman.2020.113582 Scopus 2 s2.0 85096400082 Thermal energy recovery Sewage treatment Solar powered water source heat pump Linear model Tie series Thermal energy recovery from a sequencing batch biofilter granular reactor SBBGR on a pilot scale Evaluation of the effects of energy extraction on the depuration process, process effectiveness, and results scalability Barca Emanuele; De Sanctis Marco; Altieri Valerio Guido; Di Iaconi Claudio. CNR IRSA, Via F. De Blasio 5, Bari, 70132, Italia Urban wastewater is a valuable source of clean energy available for both building conditioning and hot sanitary water production, thus reducing primary energy demand and greenhouse gas emissions. In the present study, the integration of a highly efficient solar assisted fully off the grid water source heat pump SHP with a sequencing batch biofilter granular reactor SBBGR is tested on a pilot scale for recovering and reusing thermal energy generated during the depuration process. The prototype was designed to simulate wastewater production 240 L/d , domestic hot water DHW 152 L/d at 40 °C , and space heating 20 25 °C energy demand for a one person equivalent. Three set temperatures for heat extraction from the SBBGR were tested 20, 14, and 10 °C. Heat extraction had limited effects on the average SBBGR performances. The SBBGR ensured a removal efficiency close to 90% for total suspended solids TSS , chemical oxygen demand COD , and ammonia, whereas a decrease in total nitrogen TN removal efficiency, namely from 75% to 71%, was observed with the operating temperature decrease. Energy recovery data suggested that the energy extracted from the SBBGR might cover the energy demand for DHW production or space heating from April to October. Thus, the collected energy data was modeled with the following purposes highlighting the key parameters for optimizing energy recovery, quantifying the share of recoverable energy derived the microbial metabolism, and supporting or rejecting the scalability of the results. The model outcomes confirmed that the temperature difference between the sewage and heat extraction set point temperatures was the key parameter for energy recovery and succeeded in estimating the contribution of microbial metabolisms i.e. about 3.2 kWh/m3 × d . However, the estimation of the full scale recoverable energy was partially biased by the impact of the environmental conditions on the pilot. Preprint http //www.scopus.com/record/display.url eid=2 s2.0 85096400082 origin=inward Articolo in rivista Pergamon. 0196 8904 Energy conversion and management Energy conversion and management Energy convers. manag. Energy conversion and management. claudio.diiaconi DI IACONI CLAUDIO emanuele.barca BARCA EMANUELE marco.desanctis DE SANCTIS MARCO |
