Pilot Plant Scale Research Articles

Photocatalytic Degradation of Losartan with Bismuth Oxychloride: Batch and Pilot Scale Demonstration

The solar-induced semiconductor photocatalytic process is one of the greenest and most promising technologies for the elimination of pharmaceuticals in aqueous media. In the context of this study, a bismuth oxychloride (BiOCl) photocatalyst was fabricated and characterized by its morphology, crystallographic structure, and optical properties. Its photocatalytic efficiency was tested towards the degradation of Losartan (LOS), a medication used to treat high blood pressure, in water using a solar simulator. The as-prepared BiOCl exhibited significant photocatalytic efficiency, achieving complete degradation of 0.3 mg/L LOS in short periods of irradiation (15–30 min). The examined system showed optimal efficiency using 500 mg/L of BiOCL (kapp = 0.21 min−1) and pH 3 (kapp = 0.32 min−1). However, LOS removal significantly decreased in environmentally relevant water matrices, including wastewater (kapp = 0.006 min−1) and bottled water (kapp = 0.023 min−1). Additional tests carried out in synthetic water matrices showed that the LOS degradation rate was reduced by more than 40% in the presence of humic acid (kapp = 0.016 min−1) and bicarbonates (kapp = 0.029 min−1), while chlorides did not affect the overall efficiency. Moreover, photogenerated holes and singlet oxygen were the dominant oxidative species. The efficiency of the BiOCl photocatalyst towards LOS degradation was further studied using a flat plate pilot-plant scale photoreactor. It was found that more than 75% of LOS was removed after 100 kJ/L of accumulated solar irradiation. The results obtained in the pilot-plant unit confirmed the suitability of BiOCl as a potential photocatalytic material.

Robust real-time optimization and parameter estimation of post-combustion CO2 capture under economic uncertainty

The operational cost of post-combustion carbon capture remains the principal factor impeding its uptake, thus real-time optimization has been proposed for economic operation. This requires that uncertainties be estimated, subjecting its solutions to estimation error. Herein, we propose uncertainty estimation and real-time optimization for post-combustion carbon capture plants. Model parameters are estimated using noisy measurements to address model uncertainty; accordingly, we deploy a low-variance scheme to address noise propagation. Our approach is implemented in a pilot-scale carbon capture plant through uncertain flue gas compositions and thermodynamic activities. The proposed method results in operating points closer to the true optima, with up to 25% improvement in economics compared to alternative operational approaches. Moreover, a robust real-time optimization strategy is proposed for cases in which model parameters and economic factors are simultaneously uncertain. The robust update strategy is deployed jointly with the low-variance estimation scheme to quantify the uncertainty in each model parameter, resulting in economic improvements and a notable reduction (80%) in the set point variability over the standard update approach. Through the schemes proposed, the carbon capture plant was able to operate at set points with high capture rates, low energy consumption, and low cost. This suggests that the proposed approach is suitable for the economic optimization of other energy and carbon capture systems.

Pilot study of emerging low-energy seawater reverse osmosis desalination technologies for high-salinity, high-temperature, and high-turbidity seawater

The increasing impact of climate change has worsened drought conditions, leading to a surge in the demand for seawater desalination. However, current seawater reverse osmosis (SWRO) desalination technologies are not energy-efficient for handling the high-salinity, high-temperature, and high-turbidity seawater found in the Arabian Gulf. Therefore, a pilot-scale SWRO desalination plant was established to evaluate the new desalination technologies. The pilot plant tested high-performance SWRO membranes, meshed tube filtration (MTF) as a low-energy pretreatment for the high turbidity induced by algal blooms, and membrane capacitive deionization (MCDI) to improve permeate quality. The high-performance SWRO membrane demonstrated exceptional salt rejection and produced permeate quality in the range of 250–455 mg/L from the feed with salinities of 47,500–53,500 mg/L. MTF was effective in controlling turbidity, and the energy consumption was reduced by 77 % compared to the existing pretreatment process. Furthermore, MCDI exhibited similar levels of energy efficiency as brackish water reverse osmosis and may have the potential for future deployment by enhancing process development. Based on the pilot plant results, it is expected that a 100,000–200,000 m3/d SWRO desalination plant will have a specific energy consumption of 3.11–3.13 kWh/m3 for final product water quality at or below 200 mg/L.

Effect of the Standardized ZnO/ZnO-GO Filter Element Substrate driven Advanced Oxidation Process on Textile Industry Effluent Stream: Detailed Analysis of Photocatalytic Degradation Kinetics.

A simple process of synthesizing coated filter element substrates (FES) containing zinc oxide (ZnO) nanorods and ZnO graphene-oxide nanocomposite for a pilot-scale industrial dye-effluent treatment plant is proposed. This work reports a detailed analysis of the photocatalysis mechanism on real industrial effluent streams containing a mixture of dyes. The analysis is very relevant for conducting advanced oxidation process-assisted effluent remediation at a field-level treatment operation. Estimation of the dye concentration shows nearly complete (≥98%) degradation from an initial dye sample concentration. A detailed study for the analysis of the initial reactive dyes and their degradation products was performed for quantification and identification of the degradation products through various spectral techniques. A design of the remediation mechanism through degradation pathways is proposed for characterizing the organic compounds in the degraded dye products. A regeneration and reusability study was performed on the FES presenting the durability of the FES-designed synthesis process originally for 11 cycles and regenerated FES for six cycles for achieving a threshold of 60% degradation efficiency. The experimental results demonstrate the efficacy of FES through the designed immobilized approach for the complete remediation of textile dye effluents for a 4 h treatment plant process and the consistent operability of the FES for the combined dye wastewater treatment operations.

Quality of purula (rice seasoning for anemia from soy protein hydrolysate and seaweed) during pilot plant scale development using drum drying process

Purula is a new rice seasoning product made from soy protein hydrolysate and seaweed. It contains low molecular weight (<20 kDa) biopeptide from soybean that can enhance iron absorption and fortified with vitamin and mineral to prevent anemia. This research aimed to monitor the quality of purula and its main ingredient during pilot plant scale process. The two main ingredients of purula are soy protein hydrolysate flour and seaweed slurry. Steam flash explosion and enzymatic hydrolysis treatment were applied to the soybean, followed by drum drying to produce soy protein hydrolysate flour. Brown and green algae were blanched and grinded to make seaweed slurry. Then, they were mixed with flour mix, drum dried, and added with vitamin and mineral to produce purula. Proximate, microbiological, and heavy chemical analysis were conducted on samples taken during stages of purula processing. Moisture content and thickness of Purula flakes were examined during pilot plant process. Molecular weight of protein analysis was also conducted on raw soybean, soy protein hydrolysate, and purula. Microbiological and chemical quality of soy protein hydrolysate flour, seaweed slurry, and purula conform with the food safety requirement. This indicates that Purula is safe for human consumption. Purula flakes produced by drum drying process also share consistent results of moisture content and thickness of Purula flake within 5 days of production. Low molecular weight of protein (<20 kDa) was produced on soy protein hydrolysate and still intact on purula finished product. This study concluded that purula is able to be properly produced on pilot plant scale.

Life cycle assessment of environmental impacts for two-stage anaerobic biogas plant between commercial and pilot scales

This study presents the detailed life cycle assessment (LCA) of environmental impact potential for two-stage anaerobic biogas plants between commercial and pilot scales. It provides a comprehensive and systematic approach to evaluating the environmental impacts of producing biogas from livestock wastes in several phases: collecting, processing, and production. The commercial biogas plant (C-BP) system is located in Central Taiwan's pig farm, with 1500–2000 pigs a year. The Symnergy (symbiosis bioenergy model) biogas pilot plant (S-BP) is installed in Manado City, Indonesia. The Institute of Green Products, Feng Chia University, designed both C-BP and S-BP systems. The environmental impacts of both systems' gate-to-grave life cycles were assessed and compared using Simapro 9.0.0 software. The pilot-scale biogas plants produce bioenergy from the wastewater of the slaughterhouse. Therefore, 10,950 tonne/year of slurry feedstock flowing into the commercial biogas plant was considered a functional unit equal to 21 times larger than the pilot scale biogas plant. The LCA analyzes the impacts of three processes for feedstock collection, biogas production, and digestate production. It was found that Photochemical Ozone Creation Potential had the highest total impact on C-BP (33%), and Eutrophication had the highest impact on S-BP (33%). Both the biogas production systems of C-BP and S-BP showed very low environmental impacts, and the impacts of C-BP are lower than the S-BP. However, implementing digesters considerably reduced the potential environmental impacts of well manure feedstock handling and fertilizer applications. The LCA analysis among the three individual processes is developed to allow critical points and environmental impacts for local government. Consequently, the LCA report could help establish regional sustainability strategies for the management of livestock wastes by anaerobic two-stage biogas plant from manure.

Experimental study on the influence of electrical conductivity of hygroscopic compounds on the performance of a hygroscopic cycle

Dry climate conditions and the risk of desertification have increased significantly due to the effects of climate change. This fact, combined with the growing energy demand, leads to the need of research focused on improving the performance and efficiency of power plants. In the Hygroscopic Cycle Technology, recently implemented at industrial scale, steam condensation is performed in an absorber using solutions of hygroscopic compounds in water. Hygroscopic effects increase the condensing temperature for a given pressure, allowing the implementation of dry coolers at high ambient temperatures and eliminating cooling water consumption. In this work, due to their relevance in the cycle performance and control, the influence of the concentration of hygroscopic salts in the cycle has been studied, providing insight into proper operational ranges and key parameters. An experimental study of the influence of make-up water quality, with the concentration of impurities measured by water electrical conductivity and cycle mass flow ratio values has been performed in a pilot plant. The results, used to validate a mass and species conservation model, have allowed to obtain operational charts of the cycle and may help to reduce the amount of instrumentation required for cycle control. It was found that the decrease in electrical conductivities with boiler blowdowns in the cycle stabilized at a boiler blowdown ratio of 5%. Blowdown ratios above 10% did not result in substantially lower boiler Cycles Of Concentration in comparison with the increase of thermal energy losses and pumping power (0.42 kJ/kg for each additional 1% of blowdown). It was also found that the ratio between the cooling reflux and turbine steam conductivity had to be higher than 1.1 for condensation by absorption to occur, and that a minimum blowdown ratio of 0.04% was required to avoid using a droplet separator to control live steam quality. Hence, a compromise in the boiler blowdown ratio must be found for each particular application. Finally, hygroscopic effects in condensing pressure and temperature have been experimentally verified at pilot plant scale, leading to potentially higher cycle power output values and higher temperatures in the cooling stream of industrial power cycles, which may make it easier to reject heat from the cycle.

The effect of enzymatic interesterification on the high oleic-high stearic sunflower oil fractionation and the physico-chemical properties of stearins

Oil fractionation processes typically involve the crystallization of the most saturated triacylglycerols to facilitate the separation of the liquid phase. However, the fractionation of new high stearic oils derived from sunflower (HOHS) is not as efficient as that of tropical fats. In the present work we studied the effect of enzymatic inter esterification (EIE) on the HOHS sunflower oil fractionation. EIE altered the properties and melting point of the HOHS oil, so it eased fractionation allowing operation at lower temperatures (8 °C). These fractionations produced stearins with high saturated fatty acid contents at higher yields than the non-EIE oil (28.3% vs 18.7%). The melting profile of the stearins were also characterized. EIE stearins displayed broader melting profiles with higher crystallization onsets (from 26.3 °C to 34 °C). Fractionations proved to be reproducible at pilot plant scale. The resulting stearins exhibited a solid content of 30% at 20 °C and displayed solidification curves similar to palm-based filling fats. The results indicate that changes in fatty acid distribution in the TAG backbone critically affect TAG crystallization, which was faster and more reproducible, not requiring prior dewaxing and seeding. Moreover, the fractionation products differed, yielding stearins with higher levels of solids.

Low-cost ceramic membranes manufacture using INKJET technology for active layer deposition and validation on membrane bioreactors

The fabrication of eco-friendly ceramic membranes based on low-cost raw materials, using digital INKJET printing techniques for active layer deposition and its validation in a membrane bioreactor (MBR) has been studied. The raw materials used in the manufacture of the support layer were UA50/2 clay, chamotte, calcium carbonate and potato starch. A MBR laboratory plant was operated to treat municipal wastewater with three ceramic membranes with different grammages in the selective layer deposition. The membrane performance at laboratory scale was evaluated in terms of transmembrane pressure (TMP) evolution for a constant permeate flux, permeate quality and mixed liquor characteristics. From these experiments, it was selected the membrane which obtained the lowest TMP profile maintaining appropriate water quality parameters (chemical oxygen demand (COD) removal percentage around 90% and turbidity around 0.06 NTU). This membrane was also operated at pilot plant scale in order to validate it at higher scale. Results indicated that TMP values were in the range of 0.06 and 0.1 bar, COD removal percentage was around 98% and microbiology analysis demonstrated that the quality of the effluent, according to European regulation 2020/741, can be classified as Class A and it can be reused for non-potable purposes.

Advanced Hybrid System for Ammonium Valorization as Liquid Fertilizer from Treated Urban Wastewaters: Validation of Natural Zeolites Pretreatment and Liquid-Liquid Membrane Contactors at Pilot Plant Scale.

This study evaluates a hybrid system combining zeolites as a sorption stage and a hollow fiber membrane contactor (HFMC) for ammonia (NH3) recovery from treated urban wastewater. Ion exchange with zeolites was selected as an advanced pretreatment and concentration step before the HFMC. The system was tested with wastewater treatment plant (WWTP) effluent (mainstream, 50 mg N-NH4/L) and anaerobic digestion centrates (sidestream, 600-800 mg N-NH4/L) from another WWTP. Natural zeolite, primarily clinoptilolite, demonstrated effective desorption of retained ammonium using a 2% NaOH solution in a closed-loop configuration, resulting in an ammonia-rich brine that enabled over 95% NH3 recovery using polypropylene HFMCs. A 1 m3/h demonstration plant processed both urban wastewaters, which were pretreated by ultrafiltration, removing over 90% of suspended solids and 60-65% of COD. The 2% NaOH regeneration brines (2.4-5.6 g N-NH4/L) were treated in a closed-loop HFMC pilot system, producing 10-15% N streams with potential use as liquid fertilizers. The resulting ammonium nitrate was free of heavy metals and organic micropollutants, making it suitable for use as liquid fertilizer. This comprehensive N management solution for urban wastewater applications can contribute to local economies while achieving reduced N discharge and circularity goals.

Additive and synergistic antifungal effects of copper and phenolic extracts from grape cane and apples.

Organic viticulture seeks sustainable alternatives for eco-toxic copper fungicides to control downy mildew caused by Plasmopara viticola. (Poly)phenol-rich extracts of agricultural byproducts are known to possess antifungal activity, but high production costs often limit their actual implementation. We developed and produced novel ligninsulfonate-based grape cane extract (GCE) formulations and an apple extract on a pilot plant scale, including a detailed (poly)phenol characterization by high-performance liquid chromatography photodiode array mass spectrometry (HPLC-PDA-MS). Our GCE formulations alone reduced downy mildew disease severity in greenhouse trials by 29%-69% in a dose-dependent manner, whereas a standard application of the copper-based agent alone reached ~56%. When applied together, disease severity was diminished by 78%-92%, revealing a synergistic effect that depended on the mixture ratio. Combining GCE formulations with the apple extract, additive effects were found (80% disease severity reduction). The studied plant extracts are proposed to both substitute for and synergistically reinforce copper fungicides in grapevine downy mildew control. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Solid Flow Mapping at the Bottom Section of a Pilot-Plant Scale Riser with the Help of a Radioactive Particle Tracking Technique

Solid phase velocity measurements are performed at the bottom section of a pilot plant scale cold-flow circulating fluidized bed riser with Geldart group B solids using a radioactive particle tracking technique. Experiments are performed at different gas velocities and solid fluxes to evaluate the effect of gas velocity and solid flux on solid phase velocity in the bottom section of the riser. Different flow quantities such as mean velocity, root-mean-square velocities, and granular temperature are calculated and presented at different heights. Solid motion is seen to occur in the axial direction primarily. It is observed that axial velocity fluctuation increases with the height where radial solid velocity fluctuation decreases. Both gas–solid and solid–solid interactions are vital in determining the solid flow field. Gas–solid interaction is critical in the axial direction, while solid–solid interaction is important in the radial direction.

Life-cycle assessment and techno-economic evaluation of the value chain in nutrient recovery from wastewater treatment plants for agricultural application

The recovery of nitrogen and phosphorus is important to promote circular economy in wastewater treatment plants (WWTPs). In this study, the life cycle assessment (LCA) and techno-economic assessment (TEA) of a novel pilot-scale plant aimed at recovering ammonium nitrate and struvite for subsequent application in agriculture was conducted. The nutrient recovery scheme was implemented in the sludge line of the WWTP and included (i) struvite crystallisation and (ii) ion-exchange process combined with gas permeable membrane contactor. The LCA showed that using a fertilizer solution containing the recovered nutrients was environmentally better in most of the impact categories evaluated. Ammonium nitrate was the most important environmental contributor when using the recovered fertilizer solution as a result of the high consumption of chemicals needed for its production. The TEA illustrated that the implementation of the nutrient recovery scheme in the WWTP featured a negative net present value (NPV), primarily attributed to the high consumption of chemicals (representing 30 % of the gross cost). However, the implementation of the nutrient recovery scheme in the WWTP could be economically favourable if the cost of ammonium nitrate and struvite increased to 0.68 and 0.58 €/kg, respectively. The results of this pilot-scale study highlight that nutrient recovery considering the whole value chain for fertilizer application can be an attractive full-scale alternative from a sustainability point of view.

Optimal pre-treatment of moderately old landfill leachate at the pilot-scale treatment plant using the combined aerobic biochemical and reagent method

Landfill leachates contain highly concentrated pollutants, and their uncontrolled discharge poses significant risks to the public health and environment. This study validated a pilot-scale two-stage aerobic biochemical and reagent method for the pre-treatment of moderately old landfill leachate at a pilot-scale treatment plant with a capacity of 400 L per day. The kinetic curves of key pollutants were described using two-factor dimensionless exponential equations, allowing for predicting maximally achievable treatment effects during the first aerobic biochemical stage. The optimal duration of aerobic biochemical pre-treatment was determined based on the concept of limiting pollutant content and minimizing operating costs for the two-stage process. Reagent-based leachate pre-treatment using the modified Fenton method was verified in a batch reactor. Optimal concentrations and dosages of reagent solutions, including polyacrylamide, aluminium sulphate, ferrous sulphate, and hydrogen peroxide, were found to comply with Ukrainian regulations for wastewater discharge into sewerage networks. Key pollution indicators of pre-treated leachate, such as NH4+−N (13.4–15.5 mg × L−1), TKN (25.7–30.2 mg × L−1), BODtot (71.8–76.9 mg × L−1), and COD (390–459 mg × L−1), meet the required standards.

New Bench-Scale Method To Elucidate Active Pharmaceutical Ingredient Drying Mechanisms

Drying of an active pharmaceutical ingredient, in the form of a crystalline hydrate, was investigated using a small-scale flow cell methodology. A new laboratory tool was developed and demonstrated using a simple segregated column technique to quickly distinguish different drying mechanisms using a minimal number of experiments. For the case studied here, increasing vacuum levels improved the removal of solvents while use of nitrogen flow through the solids facilitated water removal. Additional results are presented from experiments conducted to assess the impact of the crystallization solvent system and washing on drying behavior and cake properties. A system was identified which avoided issues associated with poor cake handling and improved overall drying performance. This article provides details on the new experimental method used that helped lead to the rapid development of an improved drying process and presents results demonstrated through the pilot plant scale.

Influence of Cellulose on the Anoxic Treatment of Domestic Wastewater in Septic Tanks: Statistical Analysis of the Chemical and Physico-Chemical Parameters

Cellulose is a very common polymer in domestic wastewater (WW), representing a not negligible part of the organic substance contained in sewage. To date, many studies have highlighted the feasibility of reusing this compound in several ways (e.g., building sector, wastewater treatment, energy production, etc.) after its separation from domestic WW. However, studies about the impact of the absence of cellulose on the chemical and physico-chemical parameters of a biological process are still lacking. In this work, two pilot-scale plants were used to simulate an anoxic treatment of WW in septic tanks, with and without cellulose (CWW and NCWW, respectively), for three months. The results of the monitoring highlighted that T, pH, and electrical conductivity (EC) remained almost constants, in both cases. The Spearman correlation coefficients (SCC) for turbidity (TUR), total suspended solids (TSS), and color (COL) indicated a higher removal in the case of CWW (65%, 66%, and 56%, respectively). Organic substance and nitrogen forms showed a similar behavior with and without cellulose, but in the case of CWW, N-NH3 was highly negatively correlated with TUR (SCC: −0.54), TSS (−0.49), and COL (−0.39). A biological denitrification process was highlighted in both cases. Despite these differences, when statistically analyzing the trends of the chemical and physico-chemical parameters for CWW and NCWW, a significant difference due to the absence of cellulose was excluded. These results will be useful to the scientific community, as they exclude that the operational parameters of anoxic treatments and the effectiveness on pollutants removal can be affected in the case of preliminary cellulose separation from domestic WW for recovery/reuse purposes.

PILOT-PLANT SCALE BIOMASS PRODUCTION BY LACTOBACILLUS RHAMNOSUS GG ATCC 53103: A COMPARISON BETWEEN BATCH AND FED-BATCH FERMENTATION

Probiotics such as Lactobacilli are important in improving normal intestinal flora and hindering the growth of harmful bacteria in the digestive system. Given the above reasons, the industrial production of probiotics and the use of high-yield strains is of great importance. The present study compares the biomass production by Lactobacillus rhamnosus GG ATCC 53103 in batch and fed-batch cultures conditions at a pilot plant scale. An optimized medium containing the following compounds (g/L): glucose 112.50, sugar beet molasses 56.25, casein 18.75, yeast extract 18.75, K2HPO4 13.13, Tween 80 1.88, MgSO4.7H2O 0.3750, MnSO4. 4H2O 0.0750, CaCl2. 2H2O 0.1875 and Simethicone 1.25 was used for biomass production. During the fermentation process, culture conditions such as pH, temperature, and oxygen concentration were monitored using process analytical technology (PAT). Based on the obtained results, the maximum biomass production in the batch condition in the first 20 hours of culture in the optimized medium was about 68.14 g/L. After three stages of fed-batch culture, the biomass production by L. rhamnosus GG ATCC 53103 reached 93.5 g/L at 37°C with agitation and aeration rates of 100 rev/min and 300 VV-1min-1, respectively. Therefore, biomass production increased about 2.67-fold more than the basal medium.

Lab- and pilot-scale photo-biofilter performance with algal–bacterial beads in a recirculation aquaculture system for rearing rainbow trout

AbstractIndustrial aquaculture has proliferated due to increased world demand for fish and seafood. Aerobic bacterial biofilters typically perform the nitrogen abatement of wastewater. Recirculation aquaculture systems (RAS) require nitrifying microorganisms developed in the biofilter. Despite the advantages of these biofilters, there are disadvantages, such as the time needed to mature, decrease in oxygen concentration, accumulation of organic matter and difficulty of backflushing, among others. On the other hand, microalgae effectively eliminate nutrients-pollutants, consuming inorganic carbon, nitrogen, and phosphorus and balancing soluble oxygen, conditions not attributable to nitrifying biofilters. The current study used a photo-biofilter to determine the depuration capacity of an immobilized co-culture of microalga Tetradesmus dimorphus and nitrifying bacteria isolated from a Salmon RAS. Bacteria frorm genera Flavobacterium, Microbacterium, Raoultella, Sphingobacterium, and Pseudomonas were identified. Biofilters were tested in sequential batch (lab-scale; 2.85 L) and continuous mode (pilot-plant scale; 120 L) attached to a RAS system for rearing rainbow trout. The algal–bacterial community structure was studied using 16S rRNA gene sequencing. Results showed that at typical loading rates, the algal–bacterial community could simultaneously remove ammonium, total ammonium nitrogen (TAN), nitrate and phosphate. Moreover, the system evaluated removed TAN daily, at an average of 1.18 kg per m3 of beads. Graphical Abstract

Route Optimization of the Noncovalent Modulator of Hemoglobin PF-07059013 for Treatment of Sickle Cell Disease through a Palladium-Mediated C–O Coupling, Part II: Pilot Plant Scale Manufacture

Herein, we report the optimization of the first process chemistry route for pilot-plant-scale manufacture of PF-07059013 (1), a noncovalent modulator of hemoglobin for the treatment of sickle cell disease. Five areas of improvement are discussed in detail, namely, an alternative synthetic sequence to install the pyridone functionality before benzylic ether formation, a shorter and safer route to quinoline fragment 9, a tosyl-swap strategy to avoid isolation of a thermally unstable tosylate intermediate, Pd-catalyzed C–O coupling with low catalyst loading and efficient Pd removal, and improved final isolation of the API freebase. The new route was executed in our pilot plant facility to deliver 76 kg of API.

Cross contamination of Escherichia coli O157:H7 in fresh-cut leafy vegetables: Derivation of a food safety objective and other risk management metrics

In the present study, the distribution of Escherichia coli O157:H7 was investigated in fresh-cut lettuce by simulating a commercial process at a pilot plant scale with different initial inoculum levels. A deterministic approach was used to derive a potential Food Safety Objective (FSO) for the studied pathogen. The experimental outcomes, together with literature data, were used to develop a probabilistic exposure model for E. coli O157:H7 to elucidate potential risk management metrics, i.e., Performance Objectives (POs) and a Performance Criterion (PC) at specific process steps within the food chain of fresh-cut leafy vegetables. The proposed FSO was estimated to be −6.0 log CFU/g for E. coli O157:H7 at consumption. The experimental results indicated that the pathogen was homogeneously distributed in fresh-cut lettuce after processing. Based on the modelling results, the average concentration estimated as PO in unprocessed lettuce should be −5.8 log CFU/g to meet the proposed FSO. On the other hand, the PO established after washing and packaging (processed lettuce) showed a lower value, with −6.8 log CFU/g E. coli O157:H7. Reduction levels during the washing or disinfection step estimated as the PC should be > 2.9 log CFU/g. The establishment of PC for the washing step could be considered as a suitable measure to reach the FSO in fresh-cut leafy vegetables. The suggested POs and PC would help food businesses and authorities to establish safety targets and corrective actions to reduce the number of potentially contaminated lettuce lots on the market, thus reducing the number of E. coli O157:H7 infections.