Phosphorus Recovery Research Articles

A study on the performance of a recyclable adsorbent La@Fe for phosphate adsorption in wastewater

Phosphorus(P) is the key element of the growth of phytoplankton, and is also significant cause of water eutrophication. In this work, the magnetic Fe3O4 (FE) microspheres were employed as the core material, the La compound was coated on the surface of the FE microspheres and the adsorbent obtained was denoted as La@Fe. The effects of preparation conditions including the dosage of NaOH, the preparation time, the ratio of FE and LaCl3 (LC), and the stirring time were discussed. The optimized La@Fe has a good adsorption capacity (130–160 mg·g−1) and strong magnetic recovery capacity (43.4 emu/g). In the low concentration (1 mg·L−1), the optimized La@Fe still had an excellent performance. It can keep a good adsorption in a wide pH range (3−8). Except Na2CO3, common anions (NaHCO3, NaCl, NaNO3, Na2SO4, KF, KNO2) in the wastewater could not affect the adsorption capacity of La@Fe. After 7 regeneration, the adsorption capacity of La@Fe reduced by 25% indicating the excellent regeneration property of La@Fe. The La@Fe was analyzed by SEM, TEM, XRD, XPS, BET, and LPS, and the obtained results showed that the particles of La@Fe were spherical, the particle sizes were between 0.1 and 100μm. The main components at the surface of La@Fe was La-(OH), which adsorbed phosphate to form La-PO4. The specific surface area of La@Fe was small and the mesopores were main pore structure. In addition, the adsorption kinetics analysis indicated that the Elovich model worked well on modeling La@Fe adsorbing phosphate, so the adsorption was chemical adsorption with heterogeneous adsorbing surfaces. Adsorption isotherms experiments revealed that the increasing adsorption temperature would enhance the adsorption capacity of La@Fe. It could be obtained from the thermodynamic experiments that the adsorption process was endothermic and chemical adsorption. Therefore, La@Fe is an excellent phosphate adsorbent and has a good application prospect in the field of phosphorus recovery and adsorbent reuse.

Sustainability indicator identification and selection for an innovative conceptual system: Phosphorus recovery from dairy wastewater

In Europe, a decrease in the availability of phosphate rock resources has led to the development of emerging technologies for phosphorus recovery, with the purpose of generating products that can be used as fertilisers. An innovative conceptual system dedicated to the phosphorus recovery from dairy wastewater is considered in the paper. New technologies need to be assessed using relevant sustainability indicators. In this study, we developed an approach for identifying and selecting indicators. Based on searches of literature and expert interviews, three different tools were developed: an indicator screening framework, a questionnaire for finding actor priorities, and a list of indicator selection criteria. The new approach was successfully used to narrow down an initial set of 382 indicators identified in the literature to 26 that were considered representative and practicable for the assessment of the considered system.

Undiminished performance in simultaneous phosphorus and dye recovery via ring-opening Mg-assembled carbonitride

The multiple effects of eutrophication and refractory organic dye may pose serious environmental risks, whereas conventional adsorbents mostly suffer from the disadvantage of performance degradation in complex environments. Herein, we designed Mg-assembled carbonitride (MAC) that allowed for phosphorus (P) and selective dye recovery (methylene blue (MB) as model pollutants) simultaneously, and then successfully separated the two pollutants in a simple way to obtain pure dyes and phosphorus-containing compounds. The triazine ring conjugation framework and abundant functional groups of carbonitride facilitated the doping of Mg sites. The adsorption capacity of MAC for P (211.6 ± 2 vs 207.4 mg P·g−1) and MB (116.5 ± 3 vs 117.8 mg MB·g−1) in the binary-polluted system exhibited little difference from the individual, implying synchronous and undiminished adsorption on MAC. This was attributed to the ring-opening reaction triggered by NaOH etching and thermal decomposition, generating the two new active sites, where cyano groups (C N) interacted with P and Mg–N bonds responded with both target pollutants. Moreover, the favorable selective adsorption ability of MAC for different dyes was attributed to electrostatic attraction, surface complexation, hydrogen bonds and π-π interactions. This study provides a good reference for exploiting performance-stable multifunctional adsorbents for applications in wastewater resource recovery.

Removal and recovery of phosphorus by a long–term stabilized amorphous calcium carbonate

Phosphorus is a non–renewable resource that guarantees food production, while excessive phosphorus discharge leads to water eutrophication. Phosphorus removal/recovery could help improve water quality and ensure food security. In this contribution, silica–stabilized amorphous calcium carbonates (Si–ACC) were prepared and used to remove/recover phosphate in sludge and domestic sewage. The mechanisms were investigated via kinetic and isothermal adsorption studies and XRD, TEM, Raman, and FT–IR characterization. The results showed that the homogeneously distributed silica successfully inhibited ACC transformation and helped Si–ACC keep the amorphous feature within 680 d. During phosphorus adsorption, Si–ACC quickly transformed into calcite within 5 min and reacted with phosphorus to generate polycrystalline hydroxylapatite within 60 min. The recovered product possessed a maximum specific surface area (SSA) of 209 m2/g and available phosphorus content of 18.0 %, suggesting that Si–ACC was a promising phosphorus recovery material and the recovered product could be a potential phosphate fertilizer.

High-efficiency anaerobic digestion of soybean curb residue with simultaneous phosphorus recovery by Mg[sbnd]Fe layered double hydroxides addition

Anaerobic digestion of food waste faces several technical problems, such as process failure caused by over-acidification, low heating value of biogas, and high treatment cost of liquid digestate. Layered double hydroxides (LDH) are expected to simultaneously enhance biogas production and quality and immobilize soluble phosphorus in AD due to their excellent anion exchange capability. This study first verified the above hypothesis, indicated by a dramatically enhanced methane yield of 17 folds under a high substrate load and a high quality of generated biogas with 89 % methane content and 90 % lowered hydrogen sulfide. Meanwhile, the soluble phosphorus was efficiently reduced to 3 mg/L after AD. Moreover, the calcined product of LDH showed comparable performance, indicating the possibility of reusing LDH in the AD process. The above results implied the great potential of LDH as a multifunctional material for enhancing the efficiency of waste treatment and energy/resource conversion in the AD process.

Efficient phosphate and hydrogen recovery from sludge fermentation liquid by sacrificial iron anode in electro-fermentation system

Electro-fermentation (EF) has been extensively studied for recovering hydrogen and phosphorus from waste activated sludge (WAS), while was limited for the further application due to the low hydrogen yield and phosphorus recovery efficiency. This study proposed an efficient strategy for hydrogen and vivianite recovery from the simulated sludge fermentation liquid by sacrificial iron anode in EF. The optimum hydrogen productivity and the utilization efficiency of short chain fatty acids (SCFAs) reached 45.2 mmol/g COD and 77.6% at 5 d in pH 8. Phosphate removal efficiency achieved at 90.8% at 2 d and the high crystallinity and weight percentage of vivianite (84.8%) was obtained. The functional microbes, i.e., anaerobic fermentative bacteria, electrochemical active bacteria, homo-acetogens and iron-reducing bacteria were highly enriched and the inherent interaction between the microbial consortia and environmental variables was thoroughly explored. This work may provide a theoretical basis for energy/resource recovery from WAS in the further implementation.

Assessment of three different approaches for integrating phosphorus recovery from sewage sludge and derived products in existing wastewater treatment plants

Three different technological solutions, namely acidogenic fermentation and chemical extraction (alkaline or acidic), followed by precipitation with 1% Ca(OH)2, were investigated in the view of integrating phosphorus recovery into existing wastewater treatment plants. Experiments were conducted at the lab-scale using (i) sludge taken from biologically and chemically promoted phosphorus removal activated sludge processes and (ii) ashes obtained from sludge muffle incineration. Results highlighted the benefits of enhanced biological phosphorus removal (EBPR) systems rather than chemically promoted phosphorus removal in not only phosphorus extraction (up to 40% with EBPR) and recovery directly from secondary sludge (P precipitation between 66 and 92%), but after sludge incineration as well (P extraction up to 96% and precipitation above 96%). Acidogenic fermentation ensured the highest phosphorus release from EBPR sludge (equal to a concentration in solution of 122 mg/L P-PO43−), while the derived ashes had a lower level of metal contamination (particularly Fe and Al content < 2%). The phosphorus-rich product obtained by means of the recovery process showed relevant metal contamination (Cu, Zn, and Ni) under some operating conditions, suggesting the need for further treatments.

Optimization of phosphorus wet acid extraction from sewage sludge ashes: Detailed process insight via multi-variate statistical techniques

To tackle the issue of phosphorus (P) supply, Sewage Sludge Ash (SSA) is a promising secondary source. The goal of this research is the optimization of the wet P extraction process in the view of providing valuable insights for the process scale-up. While most of the studies relied on the “one-variable-changed-at-a-time” approach, this work applied a statistical optimization model based on the Design of Experiments technique for investigating the influence of most relevant operating conditions of extraction process on Phosphorus Extraction Efficiency (PEE) with two types of SSA characterized by different levels of alkalinity. Experimental results highlighted the importance of ash characteristics, making some SSA not suitable for cost-effective phosphorus recovery due to the high acid dosage required in extraction process. Type of acid and contact time become significant factors only for Ca-rich ashes, especially when using H2SO4 as extracting agent. Optimal operating conditions (CH2SO4 = 1.3 N, L/S = 20, t = 2 h and CHCl = 2.0 N, L/S = 10, t = 2 h for Ash#1 and CH2SO4/HCl = 0.8 N, L/S = 10 for Ash#2) resulting in high PEE (80–94%) were identified for extraction performed with H2SO4 and HCl as a function of ash characteristics.

Hydrothermal carbonization and pyrolysis in wetland engineering: Carbon sequestration, phosphorus recovery, and structural characterization of willow-based chars with X-ray μ-computed tomography

Willows from engineered wetland systems (EWS) offer a sustainable approach to wastewater treatment and biomass production. Our study assesses their potential for nutrient recovery and carbon sequestration using slow pyrolysis (600 °C) and hydrothermal carbonization (250 °C). Here, we propose EWS-pyrochars as a ready-to integrate opportunity for soil amendment, as they exhibit a predominant CO2 release and the absence of harmful compounds in pyrolysis-chromatograms, indicating higher stability than hydrochars. Using sequential P-extractions, we observed a high bioavailability in the willow-woodchips and a significant P-retention in EWS-chars—up to 92 % in pyrochars and near-complete retention in hydrochars, along with a higher labile-P fraction of 21 % in hydrochars than 5 % in pyrochars. Utilizing X-ray-based techniques, Raman spectroscopy, scanning electron microscopy, and gas physisorption, we characterized the EWS-chars' structures. We revealed innovative 3D-visualizations, which transcend previous literature by providing insights into the chars' internal porosity and quantifying, for the first time, their carbonaceous structural thickness via a meshing algorithm and the mean Feret diameter. EWS-pyrochars exhibit remarkable aromaticity with a higher concentration of overall sp2 C-atoms at 63 % vs. 43 % in hydrochars. Moreover, unlike hydrochars, which depict occluded porosity, EWS-pyrochars exhibited 92 % water storage-like pores. Although hydrochars indicated lower carbonization and thermal stability than pyrochars, their higher carbon retention (55 vs. 41 % in pyrochar) suggest superior annual benefits—on a 10 ha EWS scale—of 80-tons of carbon sequestration and 334 kg of phosphorus recovery versus 60-tons of carbon and 298 kg of phosphorus with pyrochars. Our findings suggest innovative materials for resource recovery, advancing the engineered wetland systems field, shifting their traditional use, and opening the opportunity for future integration into biorefineries.

Phosphorus removal from fermented dairy manure concurrent with polyhydroxybutyrate-co-valerate synthesis under aerobic conditions

Wastewater phosphorus removal achieved biologically is associated with the process known as enhanced biological phosphorus removal (EBPR). In contrast with canonical EBPR operations that employ alternating anaerobic–aerobic conditions and achieve asynchronous carbon and phosphorus storage, research herein focused on phosphorus removal achieved under aerobic conditions synchronously with volatile fatty acid (VFA) storage as polyhydroxybutyrate-co-valerate (PHBV). 90.3 ± 3.4 % soluble phosphorus removal was achieved from dairy manure fermenter liquor; influent and effluent concentrations were 38.6 ± 9.5 and 3.7 ± 0.8 mgP/L, respectively. Concurrently, PHBV yield ranged from 0.17 to 0.64 mgCOD/mgCOD, yielding 147–535 mgCODPHBV/L. No evidence of EBPR mechanisms was observed, nor were canonical phosphorus accumulating organisms present; additionally, the polyphosphate kinase gene was not present in the microbial biomass. Phosphorus removal was primarily associated with biomass growth and secondarily with biomass complexation. Results demonstrate that concurrent PHBV synthesis and phosphorus recovery can be achieved microbially under aerobic dynamic feeding conditions when fed nutrient rich wastewater.

Simultaneous Nitrogen Removal and Phosphorus Recovery by Anammox-Induced Magnesium Phosphate Mineralization: Interaction Mechanism between Microorganisms and Mineral Formation

Simultaneous Nitrogen Removal and Phosphorus Recovery by Anammox-Induced Magnesium Phosphate Mineralization: Interaction Mechanism between Microorganisms and Mineral Formation

Towards in-site carbon utilization and highly efficient nutrients removal: Effects of ammonium on the phosphorus recovery performance in a biofilm-based system

An alternatively anaerobic–aerobic biofilm system was operated for treating synthetic municipal wastewater for 150 days, and the effect of ammonium concentration in range of 15 mg∙L−1 - 50 mg∙L−1 on the phosphorus recovery performance was discussed. The ammonium concentration was confirmed as an important factor for balancing phosphorus accumulating organisms (PAOs) and denitrifying phosphorus-accumulating organisms (DPAOs) to affect nutrients removal and phosphorus recovery. The PAOs dominated in phosphorus removal with the ammonium less than 30 mg∙L−1, the ortho-P concentration in recovery steam was plateaued at 52 mg∙L−1. The increase in ammonium to 40 mg∙L−1 caused the seriously deterioration in PAOs activity; however, the phosphorus removal and recovery performance was decreased slightly which attributed to the vital contribution of DPAOs in phosphorus removal. The adverse effect of ammonium can be eliminated by decreasing the volume exchange ratio (VER) from 3.0 to 1.5, leading to the phosphorus concentration in recovery steam of 72.21 mg∙L−1. Meanwhile, the phosphorus removal efficiency (PRE) and total nitrogen removal efficiency (NRE) were stable at 97.8 % and 99.2 %, respectively, indicating highly efficient phosphorus recovery and nutrients removal in the biofilm system. The outcome of the present study could facilitate the establishment of an integrative technology to realize in-site carbon utilization, highly efficient nutrients removal and phosphorus recovery simultaneously in the mainstream treatment of sewage wastewater, and the study reveals the transformation pathways of P and N in the BPRR system, as well as the complex interactions between functional microorganisms.

Recovery of phosphorus from actual small-scale food establishment wastewater through the precipitation process

An essential nutrient that regulates growth is phosphorus. Excess phosphorus in the bodies of water causes eutrophication and impairs the quality of water resources. The supply of phosphorus is projected to be depleted in the next century since it is from non-sustainable mineral deposits. Phosphorus is extracted by the weathering of rock naturally and by the process called strip mining. One of the alternatives to sustain the phosphorus resources is to recover the phosphorus in wastewater. The study aimed to remove and recover the phosphate from SSFE wastewater by chemical precipitation. The phosphates from food establishment wastewater were successfully removed and recovered by the precipitation process using magnesium chloride as precipitant, the form of phosphorus recovered is a phosphate compound. Different SSFE wastewaters were gathered from different locations. The average removal efficiency of phosphate from SSFE 1 is 67.11 ± 0.22 % while the efficiency from SSFE 2 is 64.96 ± 0.62 % and from SSFE 3, the removal efficiency of 68.62 ± 0.48 % was obtained. The percent removal efficiencies of the three small-scale food establishment wastewater sources have no significant difference which means that the variations from the three sources of wastewater are not far from each other. The quality of the wastewater in terms of pH, DO, and phosphate content has been improved while the TDS slightly increased. Data obtained indicates that chemical precipitation can remove and recover phosphorus from SSFE wastewater. This study serves as a smart step for many food establishments to begin treating their wastewater with an alternative, inexpensive, and simple method.

Intensive Microalgal Cultivation and Tertiary Phosphorus Recovery from Wastewaters via the EcoRecover Process.

Mixed community microalgal wastewater treatment technologies have the potential to advance the limits of technology for biological nutrient recovery while producing a renewable carbon feedstock, but a deeper understanding of their performance is required for system optimization and control. In this study, we characterized the performance of a 568 m3·day-1 Clearas EcoRecover system for tertiary phosphorus removal (and recovery as biomass) at an operating water resource recovery facility (WRRF). The process consists of a (dark) mix tank, photobioreactors (PBRs), and a membrane tank with ultrafiltration membranes for the separation of hydraulic and solids residence times. Through continuous online monitoring, long-term on-site monitoring, and on-site batch experiments, we demonstrate (i) the importance of carbohydrate storage in PBRs to support phosphorus uptake under dark conditions in the mix tank and (ii) the potential for polyphosphate accumulation in the mixed algal communities. Over a 3-month winter period with limited outside influences (e.g., no major upstream process changes), the effluent total phosphorus (TP) concentration was 0.03 ± 0.03 mg-P·L-1 (0.01 ± 0.02 mg-P·L-1 orthophosphate). Core microbial community taxa included Chlorella spp., Scenedesmus spp., and Monoraphidium spp., and key indicators of stable performance included near-neutral pH, sufficient alkalinity, and a diel rhythm in dissolved oxygen.

Pilot-scale phosphorus recovery from biogas slurry to produce battery-grade FePO4: Chemical enhanced primary treatment coupled adsorption process

Recovering phosphorus (P) from wastewater was expected to bring win–win profits for environmental protection and clean energy industries. Ferric phosphate (FePO4) was a key raw material for lithium-ion battery production for new energy vehicles, which was a more valuable and promising product for recovering P from wastewater. There were challenges in recovering high-purity FePO4 from wastewater with complex components, especially in achieving large-scale recovery. Here, a pilot-scale platform, the Chemical Enhanced Primary Treatment (CEPT) coupled Fe@aminated-polyacrylonitrile (Fe-NH2-PAN) adsorption, was established for recovering battery-grade FePO4 from biogas slurry. The platform stably removed over 80% of PO43− from biogas slurry during long-term operation, the removed PO43− was enriched in chemical sludge and Fe-NH2-PAN, and then was leached into H2SO4 solution. FePO4 crystal was successfully recovered from the leaching solution (822.35 ± 15.91 mg/L PO43−) with a recovery rate of over 75%. Importantly, the lithium-ion battery prepared from recovered FePO4 exhibited excellent and stable electrochemical performance (with stable discharge specific capacity of 100.4–106.7 mAh/g at 1.0 C). This study provides a new path for large-scale P recovery in WWTPs.

Tomato domestication rather than subsequent breeding events reduces microbial associations related to phosphorus recovery

Legacy phosphorus (P) is a reservoir of sparingly available P, and its recovery could enhance sustainable use of nonrenewable mineral fertilizers. Domestication has affected P acquisition, but it is unknown if subsequent breeding efforts, like the Green Revolution (GR), had a similar effect. We examined how domestication and breeding events altered P acquisition by growing wild, traditional (pre-GR), and modern (post-GR) tomato in soil with legacy P but low bioavailable P. Wild tomatoes, particularly accession LA0716 (Solanum pennellii), heavily cultured rhizosphere P solubilizers, suggesting reliance on microbial associations to acquire P. Wild tomato also had a greater abundance of other putatively beneficial bacteria, including those that produce chelating agents and antibiotic compounds. Although wild tomatoes had a high abundance of these P solubilizers, they had lower relative biomass and greater P stress factor than traditional or modern tomato. Compared to wild tomato, domesticated tomato was more tolerant to P deficiency, and both cultivated groups had a similar rhizosphere bacterial community composition. Ultimately, this study suggests that while domestication changed tomato P recovery by reducing microbial associations, subsequent breeding processes have not further impacted microbial P acquisition mechanisms. Selecting microbial P-related traits that diminished with domestication may therefore increase legacy P solubilization.

Investigation of Co3O4 modified carbon black as an efficient non-noble metal oxygen reduction catalyst in self-driven phosphorus recovery systems

Phosphorus and nitrogen recovery from urine in the form of struvite via a Mg-air fuel cell (MAFC) platform has previously been reported as a promising approach to achieving sustainable development goals. However, the applicability of this technology has been hindered by the expensive cathodic catalyst, i.e., Pt/C. In this study, an efficient and cost-effective non-precious metal catalyst, the Co3O4 doped carbon black (CB-ZIF-900), was developed to maximize nitrogen and phosphate recovery from urine while reducing investment costs. CB-ZIF-900 exhibited an oxygen reduction reaction current density of 2.95 mA cm−2 and an electron transfer number between 3.7 and 3.9 in urine solution, which approached those of commercial Pt/C at the same testing conditions. Using the MAFC, over 99 % of phosphorus was removed from urine, and >95 % of phosphorus was recovered in the precipitates. Stable phosphorus removal efficiency and precipitates composition were observed over five consecutive batch experiments. Furthermore, the MAFC with CB-ZIF-900 exhibited a maximum power density of 594.89 W m−3, surpassing that with commercial Pt/C by 9.3 %. These findings underscore the utility of the highly efficient and cost-effective CB-ZIF-900 for advancing the scalability and widespread applications of self-driven phosphorus recovery systems.

Absorbing oxygen carriers promotes phosphorus recovery from sludge via the microwave thermal conversion process

This study aims to apply the Absorbing oxygen carriers (AOCs) to induce the migration and transformation of phosphorus compounds during the microwave thermal conversion of sludge so the hard-to-extract organic phosphorus (OP) can be converted to easy-to-extract inorganic phosphorus (IP) and be enriched onto the sludge char. The AOCs were recycled by screen separation from the IP-rich sludge char, with the latter being a renewable phosphorus source from sludge. The AOCs in this novel process enhanced the conversion efficiency of OP into non-apatite inorganic phosphorus (NAlP), which was further converted to apatite inorganic phosphorus (AP). Most phosphorus in the sludge char is presented in the form of orthophosphate.

Comprehensive impacts of the presence of proton exchange membrane on the efficiency of Mg-air fuel cell to remove nutrients and recover struvite

Mg-air fuel cell (MAFC) can achieve simultaneous recovery of phosphorus and nitrogen from wastewater in the form of struvite while generating electricity. This article investigated the comprehensive impacts of the presence of proton exchange membrane (PEM) on the efficiency of MAFC in treating synthetic wastewater, including phosphate and ammonium removal, power generation, and struvite generation. The results showed that the PO43−-P was completely removed within 20 min in the dural-chamber (DC) cell and the removal rate was 6.30 mg-P·cm−2·h−1, which was 1.55 times that of the single-chamber (SC) cell. The removal rate of NH4+-N in the DC cell was 3.37 mg-P·cm−2·h−1, which was 2.70 times that of the SC cell. However, the SC cell produced 63.10 mW·h of electricity, which was 4.61 times that of the DC cell. The precipitates were confirmed to be struvite, with a purity of 99.31 %(DC) and 93.95 % (SC). The low corrosion potential of Mg leads to hydrogen evolution corrosion during the reaction, resulting in low current efficiency, but the current efficiency increased with reaction time. PEM accelerated the hydrogen evolution corrosion, aggravated the magnesium corrosion, increased the internal resistance, and impaired electrical generation capacity, but provided more Mg2+ and alkalinity for the precipitation of struvite. In conclusion, the DC cell had a great capacity for removing nutrients (PO43− and NH4+) and producing high-purity struvite, while the SC cell had a strong ability to generate electricity.

Fertilising Maize with Bio-Based Mineral Fertilisers Gives Similar Growth to Conventional Fertilisers and Does Not Alter Soil Microbiome

The production of mineral fertilisers relies heavily on mineral deposits that are becoming depleted or is based on processes that are highly energy demanding. In this context, and in line with the circular economy and the European Green Deal, the recovery of nitrogen (N), phosphorus (P), and potassium (K) from organic wastes using chemical technologies is an important strategy to produce secondary raw materials for incorporation into mineral fertilisers, partially replacing the traditional sources of N, P, and K. However, there are very few studies on the agronomic and environmental effects of such substitution. The aim of this work was to evaluate plant growth under microcosm conditions and the effect on the soil microbiome of mineral fertilisers in which part of the N, P, or K content comes from bio-based materials (BBMFs), namely ash, struvite, and a patented chemical process. The crop was maize, and a metataxonomic approach was used to assess the effect on the soil microbiome. The BBMF treatments were compared with a control treated with a conventional mineral fertiliser. The conventional fertiliser performed significantly better than the bio-based fertilisers in terms of maize biomass production at the first sampling point 60 days after sowing (DAS), but at the last sampling point, 90 DAS, the BBMFs showed comparable or even better biomass production than the conventional one. This suggests that BBMFs may have a slightly slower nutrient release rate. The use of fertiliser, whether conventional or BBMF, resulted in a significant increase in microbiome biodiversity (Shannon index), while it did not affect species richness. Interestingly, the use of fertilisers modulated the composition of the bacterial community, increasing the abundance of beneficial bacterial taxa considered to be plant-growth-promoting bacteria, without significant differences between the conventional mineral fertilisers and the BBMFs. The predominance of PGPRs in the rhizosphere of crops when BBMFs are used could be part of the reason why BBMFs perform similarly or even better than conventional fertilisers, even if the rate of nutrient release is slower. This hypothesis will be tested in future field trials. Thus, BBMFs are an interesting option to make the food chain more sustainable.