Specific Consumption Rate Research Articles

Optimization of medium with perfusion microbioreactors for high density CHO cell cultures at very low renewal rate aided by design of experiments.

A novel approach of design of experiment (DoE) is developed for the optimization of key substrates of the culture medium, amino acids, and sugars, by utilizing perfusion microbioreactors with 2 mL working volume, operated in high cell density continuous mode, to explore the design space. A mixture DoE based on a simplex-centroid is proposed to test multiple medium blends in parallel perfusion runs, where the amino acids concentrations are selected based on the culture behavior in presence of different amino acid mixtures, and using targeted specific consumption rates. An optimized medium is identified with models predicting the culture parameters and product quality attributes (G0 and G1 level N-glycans) as a functionof the medium composition. It is then validated in runs performed in perfusion microbioreactor in comparison with stirred-tank bioreactors equipped with alternating tangential flow filtration (ATF) or with tangential flow filtration (TFF) for cell separation, showing overall a similar process performance and N-glycosylation profile of the produced antibody. These results demonstrate that the present development strategy generates a perfusion medium with optimized performance for stable Chinese hamster ovary(CHO) cell cultures operated with very high cell densities of 60 × 106 and 120 × 106 cells/mL and a low cell-specific perfusion rate of 17 pL/cell/day, which is among the lowest reported and is in line with the framework recently published by the industry.

Effects of dissolved carbon dioxide on growth and vertebral column of hybrid marine grouper (Epinephelus fuscoguttatus × E. lanceolatus) early advanced larvae

This study investigated the effects of different dissolved carbon dioxide (CO2) concentrations (400, 700, and 1000 ppm) on the growth and vertebral column formation of hybrid tiger grouper × giant grouper (TG × GG) in their advanced larval stage under controlled laboratory conditions for 12 weeks. Growth parameters, including specific growth rate (SGR), survival rate, food consumption (FC), and food conversion rate (FCR), were calculated at the end of the experiment. Vertebral column formation was analysed using X-radiography and osteology methods. The results showed that all growth parameters were significantly affected by CO2 concentration, with the best performances observed under 400 ppm CO2. The highest statistically significant (p < 0.05) SGR, survival rate, and FC were observed under 400 ppm CO2, whereas the lowest was observed under 1000 ppm CO2. The lowest FCR (0.40, p < 0.05) was observed in 400 ppm CO2 and the highest was observed at 1000 ppm CO2 (0.59, p < 0.05). Furthermore, larvae without vertebral column malformations were observed in 400 ppm CO2, while larvae with small angles of kyphosis were observed in 700 ppm CO2, and larvae with kyphosis, lordosis, and vertebral compression were observed in 1000 ppm CO2. Only six spine measurements out of 31 obtained under different CO2 concentrations were significantly different (p < 0.05). Overall, the results suggest that CO2 concentration plays a crucial role in the growth and vertebral column formation of TG × GG in their advanced larval stage. The optimal CO2 concentration for the aquaculture of TG × GG in their advanced larval stage was found to be 400 ppm or lower. This study highlights the importance of maintaining optimal CO2 concentrations to enhance the growth and health of fish in aquaculture systems.

P AOX1 expression in mixed-substrate continuous cultures of Komagataella phaffii (Pichia pastoris) is completely determined by methanol consumption regardless of the secondary carbon source.

The expression of recombinant proteins by the AOX1 promoter of Komagataella phaffii is typically induced by adding methanol to the cultivation medium. Since growth on methanol imposes a high oxygen demand, the medium is often supplemented with an additional secondary carbon source which serves to reduce the consumption of methanol, and hence, oxygen. Early research recommended the use of glycerol as the secondary carbon source, but more recent studies recommend the use of sorbitol because glycerol represses P AOX1 expression. To assess the validity of this recommendation, we measured the steady state concentrations of biomass, residual methanol, and LacZ expressed from P AOX1 over a wide range of dilution rates (0.02-0.20h-1) in continuous cultures of the Mut+ strain fed with methanol + glycerol (repressing) and methanol + sorbitol (non-repressing). We find that under these conditions, the specific P AOX1 expression rate (measured as either specific LacZ productivity or specific AOX productivity) is completely determined by the specific methanol consumption rate regardless of the type (repressing/non-repressing) of the secondary carbon source. In both cultures, the specific P AOX1 expression rate is proportional to the specific methanol consumption rate, provided that the latter is below 0.15g/(gdw-h); beyond this threshold consumption rate, the specific P AOX1 expression rate of both cultures saturates to the same value. Analysis of the data in the literature shows that the same phenomenon also occurs in continuous cultures of Escherichia coli fed with mixtures of lactose plus repressing/non-repressing carbon sources. The specific P lac expression rate is completely determined by the specific lactose consumption rate, regardless of the type of secondary carbon source, glycerol or glucose.

Inverse problems for a model of biofilm growth

Abstract A bacterial biofilm is an aggregate of micro-organisms growing fixed onto a solid surface, rather than floating freely in a liquid. Biofilms play a major role in various practical situations such as surgical infections and water treatment. We consider a non-linear partial differential equation (PDE) model of biofilm growth subject to initial and Dirichlet boundary conditions, and the inverse coefficient problem of recovering the unknown parameters in the model from extra measurements of quantities related to the biofilm and substrate. By addressing and analysing this inverse problem, we provide reliable and robust reconstructions of the primary physical quantities of interest represented by the diffusion coefficients of substrate and biofilm, the biomass spreading parameters, the maximum specific consumption and growth rates, the biofilm decay rate and the half saturation constant. We give particular attention to the constant coefficients involved in the leading-part non-linearity, and present a uniqueness proof and some numerical results. In the course of the numerical investigation, we have identified extra data information that enables improving the reconstruction of the eight-parameter set of physical quantities associated to the model of biofilm growth.

Treatment of wastewater using Black Soldier Fly larvae: Effect of organic concentration and load

Recent studies have investigated the use of Black Soldier Fly (BSF) larvae as a promising biological treatment process for high organic content wastewater (i.a. Leachate from municipal solid waste landfill, food processing effluents), achieving both high treatment efficiency and production of secondary resources from larval biomass (i.a. Proteins and lipids). The present study was aimed at achieving a better understanding of how organic concentration and load might influence treatment performance. Larvae were fed with three artificial wastewaters characterised by same organic substances quality (degree of biodegradability and oxidation of the organic content measured respectively as BOD/COD and TOC/COD ratios) but different organic concentrations. Each type of wastewater was tested at four different loads. Treatment performance was assessed by monitoring both larval growth (in terms of weight variation, mortality and prepupation), and variation of wastewater quality and quantity to determine organic substrate consumption (measured in terms of Total Organic Carbon, TOC). Larval starvation was observed in all tests when TOC concentrations dropped below approx. 1000 mg C/L, which, for the tested wastewater, could be assumed as the limit value for adopting BSF larvae process. Substrate concentration in the feed (mgC/L) influenced larval growth (in terms of maximum wet weight, prepupation and mortality) only when organic load was above 10 mgC/larva: the higher the load, the higher the positive impact of the substrate concentration. On the contrary, the specific substrate consumption rate (vS, mgC/larva/day) appeared not to be influenced by substrate concentration but only by the organic load, with a Michaelis Menten like relationship. Accordingly, substrate load can be assumed as a design parameter for BSF treatment process, while substrate concentration might only influence potential resource recovery from larval biomass.

Consumption and degradation of different consumer plastics by mealworms (Tenebrio molitor): Effects of plastic type, time, and mealworm origin

The larvae of the Tenebrionidae-family beetles, i.e., mealworms, have been identified as potential consumers of polystyrene (PS). This may have major implications for reduction of PS waste in the environment. However, there is a lack of information on the ability of mealworms to consume other types of plastics beyond PS and quantify their degradation rates. The purpose of this work is to systematically determine the ability of mealworms to consume other sources of commonly used commercial plastics [e.g., polypropylene (PP), polyvinyl chloride (PVC), high density polyethylene (HDPE), and low-density polyethylene (LDPE)] over various periods of time (e.g., 10-, 20-, and 30-days). Additionally, this work addresses the effects of specific plastic type on changes in mealworm mass and viability. Mealworms from three different commercial sources were used. All five plastics were discovered to be consumable by mealworms to various degrees. Overall, PS was consumed most, with average consumption rates of 7.02 (±0.66), 7.13 (±2.37), and 8.70 (±1.38) mg plastic consumed per 100 mealworms per day from three different sources. This was followed by PP, which had average consumption rates of 2.53 (±0.03), 4.55 (±2.97), and 3.21 (±1.39) mg plastic consumed per 100 mealworms per day. Overall, 9.11 mg PS were consumed by 100 mealworms per day, and 0.85 mg PS were consumed by 1 g mealworm per day. The other three plastics (PVC, HDPE, and LDPE) were the least favorable for mealworm consumption. Novel findings from this work indicate that mealworms lost mass during the first 10 days of the experimental time period, yet they still consumed plastics. Additionally, larger-sized mealworms displayed a lower viability rate. Overall, this work contributes new understanding for the capabilities of mealworms to degrade several common and environmentally problematic (i.e., recalcitrant) plastics. Additionally, it provides critical information, such as Specific Consumption Rates (SCRs), for several plastics that have not been previously reported.

Development of a Digital Well Management System

The modern oil industry is characterized by a strong trend towards the digitalization of all technological processes. At the same time, during the transition of oil fields to the later stages of development, the issues of optimizing the consumed electricity become relevant. The purpose of this work is to develop a digital automated system for distributed control of production wells using elements of machine learning. The structure of information exchange within the framework of the automated system being created, consisting of three levels of automation, is proposed. Management of the extractive fund is supposed to be based on the work of four modules. The “Complications” module analyzes the operation of oil wells and peripheral equipment and, according to the embedded algorithms, evaluates the cause of the deviation, ways to eliminate it and the effectiveness of each method based on historical data. The “Power Consumption Optimization” module allows integrating algorithms into the well control system to reduce energy consumption by maintaining the most energy-efficient operation of pumping equipment or optimizing its operation time. The module “Ensuring the well flow rate” allows you to analyze and determine the reasons for the decrease in production rate, taking into account the parameters of the operation of adjacent wells. The Equipment Anomaly Prediction module is based on machine learning and helps reduce equipment downtime by predicting and automatically responding to potential deviations. As a result of using the proposed system, many goals of the oil company are achieved: specific energy consumption, oil shortages, and accident rate are reduced, while reducing the labor costs of engineering and technological personnel for processing the operation parameters of all process equipment.

Performance assessment of passive indirect solar dryer comparing without and with heat storage unit by investigating the drying kinetics of carrot

The present study examined the drying kinetics of carrots and the effectiveness of passive indirect solar dryer without (setup-I) and with (setup-II) thermal energy storage (TES). A module containing paraffin wax as a TES unit was incorporated after the test was completed in setup-I to create setup-II. The sample slices were dried in setup-I and setup-II at a drying rate of 0.5 and 0.59 kg/h, respectively. In setup-I, the sample dried from 9.13 to 0.478 dry basis (db) in 16 h, whereas, setup-II took 15 h. The thermal efficiency of the solar heater and actual heat supply for the same were 56.84 & 60.79% and 705.64 & 730.45 W, respectively. Similarly, the average heat and mass transfer coefficients (h and hm) were 6.32 & 7.08 W/m2 K and 0.0055 & 0.0062 m/s, and average effective diffusivity (De) for the same setups were 6.7 × 10−9 and 7.24 × 10−9 m2/s, respectively. Furthermore, the specific energy consumption and specific moisture extraction rate for the same were 3.5 & 0.28 kWh/kg and 0.29 & 3.62 kg/kWh, respectively. Setups I and II had an average drying efficiency of 7.5 and 10.25%, respectively. The activation energy was evaluated for both setups. The De, h and hm were correlated with moisture content for both setups. In addition to helping the drying process to be completed in a day, setup-II performed better in all the evaluated parameters than setup-I. To ensure the reliability of the results, an experimental uncertainty analysis was conducted.

Бактерии-деструкторы дибутилфталата, выделенные из ризосферы мятлика лугового (Poa pratensis L.)

The ability of three bacterial strains of the class Actinomycetes, isolated from the rhizosphere of bluegrass (Poa pratensis L.) plants growing in the industrial development area of the Verkhnekamsk salt deposit (Perm krai), to grow on dibutyl phthalate (DBP) as the only source of carbon and energy was studied. Based on 16S rRNA gene analysis, it was shown that the strain Rh7bel showed similarity at 100% level with Rhodococcus wratislaviensis NBRC 100605T, and strains NKDBFbel and NKDBFgelt are phylogenetically close to two type strains of the species Pseudarthrobacter oxydans and Pseudarthrobacter polychromogenes (99.83% similarity). DBP-degrading strains are characterized by efficient growth on the key metabolite of DBP degradation, ortho-phthalic acid, and utilization of this metabolite. The strain Rhodococcus sp. Rh7bel demonstrated the highest rates of DBP utilization: the maximum specific substrate consumption rate was 0.018±0.002 h-1, substrate utili-zation was 70.7% in 72 hours (initial DBP concentration 0.2 g/L). Thus, rhizosphere DBP-degrading strains Rhodococcus sp. Rh7bel, Pseudarthrobacter spp. NKDBFbel and NKDBFgelt are promising for further study and development of technology for phytoremediation of soils contaminated with phthalates.

Analysis on the influence law of traction speed on the cutting performance of coal containing hard concretion

Due to the great differences in mechanical properties between hard concretion and coal, the shearer drum cutting coal and rock containing hard concretion will inevitably lead to a series of problems, such as severe load impact, increased cutting specific energy consumption and low coal loading efficiency. Taking the cutting part of a thin coal seam shearer in service in the target mining area as the prototype, the mechanical models of shearer drum and rocker arm are established by using UG, and the discrete element model of coal wall with hard concretions is built by importing it into EDEM. The influence law of traction speed on coal loading rate, drum load and cutting specific energy consumption is analyzed, and the corresponding fitting relationship function is obtained. Taking the traction speed as the design variable, and the drum load, cutting specific energy consumption and coal loading rate as the comprehensive indicators, a multi-objective optimization function is established. The optimal solution is obtained by using NSGA II optimization algorithm, and the accuracy of the simulation is verified by experiments. This method has certain engineering significance for the reasonable selection of shearer traction speed.

Applications of advanced oxidation processes (Electro‑Fenton and sono‑electro‑Fenton) for COD removal from hospital wastewater: Optimization using response surface methodology

This study investigates the feasibility of applying electro-Fenton (EF) and sono-electro-Fenton (SEF) processes for the removal of chemical oxygen demand (COD) from the hospital wastewater generated by the Al-Diwaniyah hospital located in Iraq. The effect of various operational parameters on COD removal was studied based on the response surface methodology (RSM). The optimal conditions for maximum removal of COD using EF were found to be a current density of 19.293 mA/cm2, an H2O2/COD ratio of 1.4, and a time duration of 46.67 min, in which 96.27% COD removal was obtained at a specific energy consumption rate of 7.325 kWh/kg COD. In the EF process, results showed that the H2O2/COD ratio has the most effect on COD removal, with a 61.76% contribution, followed by the current density, which contributed 22.78%. The suitability of the model equation was confirmed by its high R2 value (98.90%). For the SEF system, the best operating conditions were found to be a current density of 10 mA/cm2, an H2O2/COD ratio of 0.2, and a time duration of 46.67 min, in which 88.31% COD removal was obtained at a specific energy consumption of 2.082kWh/kg COD. Adopting the SEF process showed that the specific energy, H2O2, and iron consumptions are lowered by 1/3.5, 1/7, and 1/2, respectively, compared to those observed at the optimum conditions for maximizing EF alone. Results revealed a significant improvement in the EF system when combined with the ultrasonic (US) technique, wherein a considerable amount of COD removal with a final value of COD less than 100 ppm was observed at a lower cost in terms of energy consumption and the chemicals used, thus confirming the role of SEF for treating hospital wastewater using a more efficient and cost-effective approach.

Insight into the comprehensive effect of carbon dioxide, light intensity and glucose on heterotrophic-assisted phototrophic microalgae biofilm growth: A multifactorial kinetic model

Heterotrophic-assisted photoautotrophic microalgae biofilm cultivation was an alternative way to realize CO2 reduction and wastewater treatment. Growth kinetics supplied a channel to better understand how the cultivation conditions affect microalgal growth and CO2 reduction. However, the two growth modes (heterotroph and photoautotroph) have different needs for organic and inorganic nutrients. Thus, combining the threshold theory and multiplication theory, an integral multifactorial kinetic model that looking insight into the comprehensive effect of glucose, CO2, light intensity, and nitrate was developed for heterotrophic-assisted photoautotrophic microalgae biofilm growth in this study. R2 between model and experiment was 0.99. It predicted the maximum specific growth rate and maximum CO2 consumption rate of heterotrophic-assisted photoautotrophic microalgae biofilm was 1.868 h−1 and 1.02 h−1, respectively. This model fully explained the influence of the main factors on microalgae biofilm growth and reasonably predicted the growth rate of microalgae biofilm under different growth conditions.

Medium Formulation and Fed-Batch Cultivation of &lt;i&gt;Methylosinus trichosporium&lt;/i&gt;

Methanotrophs display the ability to consume methane as a carbon source and produce a wide-range of high-value products, e.g. ectoine/hydroxyectoine, poly-b-hydroxybutyrate (PHB), single cell protein, extracellular polysaccharides and lipids. Usually methanotrophs show low specific substrate consumption rates, which restricts their application at pilot and industrial scale. Thus, in order to reduce the time and costs of the cultivation process, it is vital to accelerate the growth of applied organisms. Usually, methanotrophic bacteria cultivations are carried out using fully synthetic mineral mediums (nitrate mineral salts medium (NMS)) without the addition of any growth factors. Potentially, higher biomass growth and substrate uptake rates can be achieved by supplementing the growth medium with vitamins, amino acids etc. or by using more bioavailable substrates.The aim of our research was to study the influence of growth factors such as vitamins, and different nitrogen sources (yeast extract, yeast nitrogen base with/without amino acids and tryptone) on the growth of Methylomonas methanica, Methylomicrobium alcaliphilum and Methylosinus trishosporium.Experiments for studying the influence of growth factors were carried out in shake flasks by varying the medium compositions and analyzing the effects of said variations on the kinetics of the cultivation, e.g. specific biomass growth rate and biomass yield from substrate.Subsequent tests of the developed nutrient medium, which promotes higher biomass growth rates, were carried out in laboratory 5 L bioreactor Methylosinus trishosporium cultivations to study the main process parameters.From the statistical analysis of experimental data it was observed, that supplementation of the growth medium with yeast extract or tryptone, seems to promote the growth rate of methanotrophs, when methanol is used as the main substrate. Furthermore, specific growth rates observed during cultivations in mediums containing vitamins (including cobolamin) also seem to positively affect the biomass growth rate. Based on the results of lab-scale bioreactor cultivations, using the identified medium composition it was possible to achieve a maximal biomass specific growth rate of 0.15 L⸱h‑1 and productivity of 0.16 g⸱L-1⸱h-1.

Acetate accumulation and regulation by process parameters control in Chinese hamster ovary cell culture.

Chinese hamster ovary (CHO) cells represent a group of predominantly used mammalian hosts for producing recombinant therapeutic proteins. Known for theirrapid proliferation rates, CHO cells undergo aerobic glycolysis that is characterized by fast glucose consumption, that ultimately gives rise to a group of small-molecule organic acids. However, only the function of lactate has been extensively studied in CHO cell culture. In this study, we observed the accumulation of acetate from the late exponential phase to harvest day, potentially contributing to the pH decline in late culture stage regardless of lactate consumption. In addition, we evaluated the acidification of the fresh media and the cell culture suspension, and the data revealed that acetate presented a lower acidification capacity compared to lactate and exhibited limited inhibitory effect on cells with less than 20 mM supplemented in the media. This study also explored the ways to control acetate accumulation in CHO cell culture by manipulating the process parameters such as temperature, glucose, and pH control. The positive correlation between the specific glucose consumption rate and acetate generation rate provides evidence of the endogenous acetate generation from overflow metabolism. Reducing these parameters (temperature, glucose consumption) and HCl-controlled low pH ultimately suppress acetate build-up. In addition, the specific acetate generation rate and relevant glucose consumption rate are found to be a metabolic trait associated with specific cell lines. Taken together, the results presented in these experiments provide a means to advance industrial CHO cell culture process control and development.

Experimental study on combustion of an automotive diesel engine fuelled with CNG

Presenting the influence of compressed natural gas (CNG) used as alternative fuel on the combustion of an automotive diesel engine represents the main objective of this paper. The paper studies brake specific energetic consumption, in-cylinder pressure and pressure rise rate, carbon dioxide, nitrogen oxides, smoke and hydrocarbons emissions at 2000 rev/min and at 40%, 55% and 70% load. Low carbon content of the alternative fuel will determine lower CO2 at all loads; NOx and smoke emissions are influenced by both energetic substitution and engine operating regime. HC emission will reach higher levels in diesel-gas mode than in conventional mode as the homogeneous percentage of the charge per cycle grows with the quantity of CNG admitted into the cylinder. In all cases in-cylinder pressure and pressure rise rate are higher in dual-fuel mode than those in conventional operating mode due to higher quantity of premixed charge developed during the ignition delay phase. The higher LHV (lower heating value) and the gaseous state of CNG will determine at all loads lower brake specific energetic consumption. Smoke emission will be negatively influenced in low to medium loads but in high loads it will drop by more than 30 percent.

Spent media analysis suggests cultivated meat media will require species and cell type optimization

Cell culture media design is perhaps the most significant hurdle currently facing the commercialization of cultivated meat as an alternative source of dietary protein. Since media optimization for a specific culture system requires a significant amount of effort and investment, a major question remaining is whether media formulations can be easily shared across multiple production schemes for cells of different species and lineages. Here, we perform spent medium analysis to compare the specific nutrient utilization of primary embryonic chicken muscle precursor cells and fibroblasts to the murine C2C12 myoblast cell line. We demonstrate that these related cell types have significantly different nutrient utilization patterns collectively and on a per-cell basis, and that many components of conventional media do not appear to be depleted by the cells. Namely, glucose was not consumed as rapidly nor as completely by the chicken muscle precursors compared to other cells overall, and there were significant differences in specific consumption rates for several other key nutrients over the first day of culture. Ultimately, our results indicate that no one medium is likely ideal and cost effective to culture multiple cell types and that novel methods to streamline media optimization efforts will be important for the industry to develop.

Effect of Polydextrose on the Growth of Pediococcus pentosaceus as Well as Lactic Acid and Bacteriocin-like Inhibitory Substances (BLIS) Production.

Pediococcus pentosaceus was cultivated in MRS medium supplemented or not with polydextrose under different conditions in order to evaluate its effect on cell growth, lactic acid and bacteriocin-like inhibitory substance (BLIS) production. Independent variables were pH (4.0, 5.0, 6.0), rotational speed (50, 100, 150 rpm), polydextrose concentration (0.5, 1.0, 1.5%) and temperature (25, 30, 35 °C), while cell concentration and productivity after 24 h, maximum specific growth rate, specific rate of substrate (glucose) consumption, volumetric and specific lactic acid productivities, yields of biomass and lactic acid on consumed substrate were the dependent. The maximum cell concentration (10.24 ± 0.16 gX L−1) and productivity (0.42 ± 0.01 gX L−1 h−1) were achieved at pH 6.0, 35 °C, 150 rpm using 1.5% polydextrose, while the maximum specific growth rate (0.99 ± 0.01 h−1) and yield of biomass (2.96 ± 0.34 gX gS−1) were achieved at the same pH and polydextrose concentration, but at 25 °C and 50 rpm. The specific substrate consumption rate (0.09 ± 0.02 gS gX−1 h−1) and the volumetric lactic acid productivity (0.44 ± 0.02 gP L−1 h−1) were maximized at pH 6.0, 35 °C, 50 rpm and 0.5% polydextrose. BLIS produced in this last run displayed the highest antibacterial activity against Escherichia coli, while the same activity was displayed against Enterococcus faecium using 1.5% polydextrose. These results appear to be quite promising in view of possible production of this BLIS as an antibacterial agent in the food industry.

Fast granulation of flocculent activated sludge by mycelium pellet and wastewater biological treatment performance

To investigate the universality of mycelium pellet (MP) assisted flocculent activated sludge (FAS) granulation, four different filamentous microbes (Aspergillus niger, Aspergillus fumigatus, Phanerochaete Chrysosporium and Streptomyces albicans) were used for bio-flocculation assisted activated sludge granulation, and the physicochemical properties and biological activity of aerobic granular sludge (AGS) with MP as skeleton were monitored. The results showed that inoculation of MP for an assisted flocculation strategy was better than filamentous spores. Spherical and rod-shaped microbes of FAS alternately adhered to different areas of the MP to form granular sludge with dense structure. Under the optimized conditions, the FAS biomass aggregated on four MPs reached 1.24–1.89 g/g, and the respiratory activity of corresponding MP-based AGS (MP-AGS) were 36.52–56.95 mgO2/gVSS of specific oxygen consumption rate. Compared to FAS, MP-AGS present better sedimentation performance (45–55 m/h of settling rate) and higher biological enzyme activity related to organic matter degradation and nitrogen conversion (49.82–60.37 mgTF/(gVSS∙h) of dehydrogenase, 0.26–0.42 mgNO2−-N/(min∙mg protein) of nitrate reductase). TN and TP removal efficiencies of MP-AGS were 9.96 %–19.59 % higher than those of FAS under high influent loads. This study confirmed the feasibility of mycelium pellet assisted flocculent activated sludge granulation using different microbes.

Ion transport channels in redox flow deionization enable ultra-high desalination performance

Redox flow deionization (RFD) is an emerging derivative of redox flow cell technology that desalinizes salt water while simultaneously storing energy. However, conventional RFDs are limited by high specific energy consumption and low salt removal rates caused by low ionic conductivity in low-salinity ranges (especially < 3000 mg L–1). This study investigates the potential of ion transport channels composed of ion exchangers to enhance ionic conductivity in low-salinity ranges. The RFD cell with ion exchangers (IE-RFD) exhibited significantly lower resistance and specific energy consumption than conventional RFD cells when processing low salinity feeds. A finite element analysis demonstrated that the current density in the ion exchangers, especially where the ion exchangers were in contact, was much higher than that of the surrounding solution, indicating effective ion transport in low-salinity ranges. The IE-RFD cell showed excellent desalination performance (99.4% at 10 000 mg L–1) and low energy consumption (0.99 Wh L–1). We did not observe any deterioration in performance over 10 d of continuous desalination. Compared with other electrochemical desalination technologies, e.g., membrane capacitive deionization, flow capacitive deionization, and traditional RFD, the IE-RFD is superior in terms of energy consumption, salt removal ability, and stability. This study described an efficient strategy to enhance the desalination performance of RFDs through ion transport channels. With further optimization, this technology could help to alleviate the critical global demand for fresh water using minimal energy.

Treatment of wastewater using black soldier fly larvae, under different degrees of biodegradability and oxidation of organic content

The biological treatment process based on the metabolism of Black Soldier Fly (BSF) larvae proved to be a highly promising technique for the treatment of high organic content (HOC) wastewater, such as sewage from food industries, leachate from municipal solid waste (MSW) landfill, etc. The present study was aimed at achieving a better understanding of how biodegradability and degree of oxidation of organic content might influence treatment performance and biomass quality. Six leachates characterised by similar COD (Chemical Oxygen Demand) but different BOD5/COD (Biochemical Oxygen demand/COD) and TOC/COD (Total Organic Carbon/COD) ratios were tested. By combining these ratios, the BOD5/TOC ratio was introduced to take into account the effect of both leachate properties (biodegradability and oxidation degree). Process treatment performance was significantly influenced by the quality of organic substances. Higher BOD5/TOC values (higher biodegradability and lower oxidation degree) resulted in a greater and faster larvae growth, with final wet weight of between 49.2 and 91.9mg/larva; lower mortality between 5 and 32%; higher prepupation percentages ranging from 4 to 21% and higher specific substrate consumption rate with values varying from 0.051 to 0.063 mgTOC/mg larva/d, up to 3-fold higher than values obtained using conventional activated sludge based on COD consumption. Conversely, no significant differences were detected in larvae protein and lipid contents, including the profiling of fatty acids.