The forward osmosis (FO) is an emerging technique for high quality concentration of liquid foods. Polyphenols are natural compounds with important health function in fruit and vegetable juice. In ...this study, the impacts of membrane property, feed solution (FS) pH value, draw solution (DS) composition and concentration, and membrane fouling on rejections of 9 food polyphenols by FO were investigated. Polyphenol rejection was mainly dominated by size exclusion and electrostatic repulsion. Membrane with higher negative charge and selectivity exhibited higher rejection. The increased pH of FS could enhance negative charge of membrane and thus increased the rejection. Reverse solute diffusion of DS could also enhance rejection via hindering the forward diffusion of polyphenol. The pectin fouling layer acting as the additional filtration barrier could increase the rejection of most selected polyphenols. However, the rejection of polyphenols with smaller molecular size (less than 23.07 Å2) decreased with the pectin fouled membrane and this might be attributed to the effect of cake-enhanced concentration polarization. The present study revealed the fate of polyphenol in FO and provided vital information to further advance the FO application.
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•Polyphenol rejection is dominated by size exclusion and electrostatic repulsion.•Membrane with higher negative charge and selectivity exhibits higher rejection.•The effect of pH on polyphenol rejection bases on the electrostatic repulsion.•Higher reverse diffusion of solutes leads to higher rejection of polyphenol.•Rejection by fouled membrane involves complex mechanisms combination.
•D. magna ingested more MPs at low-medium algal conc. and less at high algal conc.•The ingested food conc. affected the gut residence and excretion of MPs.•Algal presence strengthened the ingestion ...of green MPs but not for red and clean.•The number of MPs adhering to the body increased with increasing algal conc.
Aquatic organism uptake and accumulate microplastics (MPs) through various pathways, with ingestion alongside food being one of the primary routes. However, the impact of food concentration on the accumulation of different types of MPs, particularly across various colors, remains largely unexplored. To address this gap, we selected Daphnia magna as a model organism to study the ingestion/egestion kinetics and the preference for different MP colors under varying concentrations of Chlorella vulgaris. Our findings revealed that as the concentration of Chlorella increased, the ingestion of MPs by D. magna initially increased and then showed a decline. During the egestion phase within clean medium without further food supply, an increase in food concentration during the ingestion phase led to a slower rate of MP discharge; while when food was present during the egestion phase, the discharge rate accelerated for all treatments, indicating the importance of food ingestion/digestion process on the MPs bioaccumulation. Furthermore, in the presence of phytoplankton, D. magna demonstrated a preference for ingesting green-colored MPs, especially at low and medium level Chlorella supply, possibly due to the enhanced food searching activities. Beyond gut passage, we also examined the attachment of MPs to the organism's body surface, finding that the number of adhered MPs increased with increasing food concentration, likely due to the intensified filtering current during food ingestion. In summary, this study demonstrated that under aquatic environment with increasing phytoplankton concentrations, the ingestion and egestion rates, color preferences, as well as surface adherence of MPs to filter feeding zooplanktons will be significantly influenced, which may further pose ecological risks. Our results offer novel insights into the unintentional accumulation of MPs by zooplankton, highlighting the complex interactions between food availability and MPs accumulation dynamics.
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This study investigated the ingestion behavior of zebrafish exposed to microplastic particles (MPs) at different concentrations, presented alone or in a mix with food particles. Zebrafish showed ...spitting behavior after ingesting micro-sized (247.5 μm) polyethylene particles (i.e., MPs), with prey-capture time increasing when food and MPs were supplied simultaneously. Fish were compelled to ingest MPs with food, and the accumulation percentage (ingested particles/supplied particles) was quantified as 0.5 to 9.4% with increasing food volume. However, the accumulation percentage was determined as 0.0 to 1.0% under exposure to MPs only, and as 3.8 to 4.3% at high MP concentrations when the food concentration was fixed. Overall, these results demonstrate that small freshwater organisms can recognize that MPs are not food items. Under laboratory conditions, zebrafish rarely discriminate between food and MPs when both are presented together, and the indiscriminate feeding behavior becomes clearer as more food is available.
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•Zebrafish recognize microplastics as inedible materials•It was evidenced by the spitting behavior.•The ingested amount of MP depended on food concentration.•The MP accumulation was higher in the presence of food.
•Individual-based model to study the production of an invasive copepod.•Model integrates the effect of food concentration on several individual endpoints.•Calibration of the model benefits from ...measures obtained in vivo.•Quantify the combined impact of food and predation on egg and offspring production.
Arctodiaptomus dorsalis is an invasive calanoid copepod originally from America and has recently established a population in Lake Taal in the Philippines. It has been proposed that eutrophication due to aquaculture contributes to the establishment and success of this species. This study aimed to clarify this hypothesis by quantifying the effect of increasing food concentration on the reproduction of A. dorsalis using an Individual-Based Model. We parameterized food concentration-dependent equations to simulate the effect of different food concentration on the reproductive traits (latency time, embryonic development time, clutch size, and hatching success) of this species using data from the literature and simulated the reproduction of 1000 independent females for 20 days at different food concentration, taking into account the variability among individuals. The simulation results showed that the cumulative production of eggs and offspring increased continuously with time when the food concentration was above 3.2 × 104 cells mL−1, suggesting that this value was the threshold concentration required for stable reproduction of A. dorsalis. This value is not particularly low compared to other copepods. Hence, our result revealed that the food use efficiency of A. dorsalis is not particularly outstanding and urge the need of a comparison with native species to confirm a possible superiority. We suggest that A. dorsalis has filled the ecological niche left vacant by the disappearance of the original species due to the deterioration of water quality caused by the eutrophication of the lake. The reproductive cycle model developed in this study constitutes a necessary step in the development of a complete population dynamics model, which can help clarify the invasive abilities of A. dorsalis.
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As emerging membrane technologies, forward osmosis (FO) and membrane distillation (MD), which work with novel driving forces, show great potential for liquid food concentration, owing to their low ...fouling propensity and great driving force. In the last decades, they have attracted the attention of food industry scientists in global scope. However, discussions of the FO and MD in liquid food concentration advancement, membrane fouling, and economic assessment have been scant. This review aims to provide an up‐to‐date knowledge about liquid food concentration by FO and MD. First, we introduce the principle and applications of FO and MD in liquid food concentration, and highlight the effect of process on liquid food composition, membrane fouling mechanism, and strategies for fouling mitigation. Besides, economic assessment of FO and MD processes is reviewed. Moreover, the challenges as well as future prospects of FO and MD applied in liquid food concentration are proposed and discussed. Comparing with conventional membrane‐based or thermal‐based technologies, FO and MD show outstanding advantages in high concentration rate, good concentrate quality, low fouling propensity, and low cost. Future efforts for liquid food concentration by FO and MD include (1) development of novel FO draw solution (DS); (2) understanding the effects of liquid food complex compositions on membrane fouling in FO and MD concentration process; and (3) fabrication of novel membranes and innovation of membrane module and process configuration for liquid food processing.
•Seston P, C:P and concentration are good indicators of herbivore growth in freshwater ecosystems.•High food quality (high P, low C:P) and quantity favor herbivore consumers growth.•Seston C:P can be ...as low as 40 in natural lakes, no detrimental effect of low C:P on Daphnia was found.•Threshold Elemental Ratio (TER) based on single algal feed studies is biased towards higher values.•Algae composition affects Daphnia growth, and cryptophytes are good food for them.
The performance of herbivore consumers in freshwater ecosystems is influenced by food quality and quantity, which are crucial factors in understanding energy flow. However, the comprehensive effects of these factors on consumer growth based on natural food research remain unclear. To address this gap, we conducted a growth experiment culturing the Cladocera Daphnia similis in natural lake water collected from 30 subtropical lakes. Our results showed that the seston concentration (SC), seston phosphorus (seston P), and seston carbon: phosphorus ratio (seston C:P, in moles) were the most important factors in influencing the growth rate of D. similis according to the Random Forest model. Specifically, the growth rate of D. similis was significantly positive correlated with SC and seston P, and significantly negative correlated with seston C:P. D. similis exhibited the optimal growth performance within the seston C:P range of 32.8 to 69.8, with a sharp decline in growth rate observed at a break point of seston C:P of 70. The combined effect of food quality and quantity on growth rate was that higher SC (≥0.26 mg C/L), lower seston C:P (≤69.80), and higher P (≥0.11 mmol/g) were associated with significantly higher growth rates. Additionally, the growth rate increased significantly with the biomass of cryptophyte, indicating the importance of food composition. Our study shows that the growth rate of D. similis is co-affected by the quality and quantity of natural food. SC, seston C:P, seston P and algae composition are reliable indicators for assessing the growth rate of consumer in freshwater ecosystems. The inhibitory effect of low C:P on consumer growth should be applied with caution when assessing the development of herbivore consumers in natural lakes.
The metabolic activity of unionid mussels influences the oxygen fluxes and other physical and chemical characteristics in aquatic systems. Unionid oxygen consumption rate during digestion and its ...dependency on food availability is understudied. In laboratory conditions, we quantified the oxygen consumption rate of
Anodonta anatina
and
Unio pictorum
in response to algal concentration—0.05, 6.0 and 12.0 mg of Ash Free Dry Mass of
Chlorella vulgaris
L
−1
—and mussel dry soft-tissue mass at 19 ± 1°C. Following a 5-h feeding-period, the oxygen consumption rate (mg O
2
h
−1
) increased with algal concentration and mussel dry mass in both species during a 2-h digestion-period. The mean oxygen consumption per gram of dry mass (mg O
2
gDM
−1
h
−1
) increased with the algal concentration in both species. The oxygen consumption rate of
A. anatina
was significantly greater than that of
U. pictorum
at a given algal concentration. The
A. anatina
oxygen consumption per gram of dry mass decreased with increasing dry mass. Oxygen consumption rate during digestion shows inter-specific differences and is dependent on food availability. The findings inform the species-specific quantification of oxygen consumption, and validation is required in in situ conditions.
In the past few years, osmotic membrane systems, such as forward osmosis (FO), have gained popularity as “soft” concentration processes. FO has unique properties by combining high rejection rate and ...low fouling propensity and can be operated without significant pressure or temperature gradient, and therefore can be considered as a potential candidate for a broad range of concentration applications where current technologies still suffer from critical limitations. This review extensively compiles and critically assesses recent considerations of FO as a concentration process for applications, including food and beverages, organics value added compounds, water reuse and nutrients recovery, treatment of waste streams and brine management. Specific requirements for the concentration process regarding the evaluation of concentration factor, modules and design and process operation, draw selection and fouling aspects are also described. Encouraging potential is demonstrated to concentrate streams more than 20-fold with high rejection rate of most compounds and preservation of added value products. For applications dealing with highly concentrated or complex streams, FO still features lower propensity to fouling compared to other membranes technologies along with good versatility and robustness. However, further assessments on lab and pilot scales are expected to better define the achievable concentration factor, rejection and effective concentration of valuable compounds and to clearly demonstrate process limitations (such as fouling or clogging) when reaching high concentration rate. Another important consideration is the draw solution selection and its recovery that should be in line with application needs (i.e., food compatible draw for food and beverage applications, high osmotic pressure for brine management, etc.) and be economically competitive.
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•Both morphs of K. tropica showed significantly higher intrinsic rate of population increase at 25 °C than 20 °C and 30 °C.•Populations of both LSM and SSM decreased at any algae and ...Moina levels.•LSM of K. tropica showed higher competition capacity with M. macrocopa than SSM.
Competition and predation are the two major biotic interactions in zooplankton community. Various rotifer species exhibit polymorphism in lorica and spine morphology in the presence of predators and competitors, which effectively increases their defence competition capacity. This study compared life-history parameters between long-spined morph (LSM) and short-spined morph (SSM) of Keratella tropica at three temperatures. The results showed that both morphs showed significantly higher intrinsic rate of population increase at 25 °C than those at 20 °C and 30 °C. The intrinsic rate of population increase was significantly lower in LSM than SSM at 25 °C and 30 °C, and the net reproductive rate was significantly lower in LSM than SSM at 30 °C. These results suggested that K. tropica had cost on development of long spines, which, however, was dependent on temperature. Moreover, the competition outcome of LSM and SSM with Moina macrocopa were investigated at three densities of Scenedesmus obliquus (0.5 × 106, 1.0 × 106 and 2.0 × 106 cells/mL) and three initial densities of M. macrocopa (0.1, 0.3 and 0.9 ind./mL), revealing that both LSM and SSM populations decreased significantly at all tested algal densities and Moina levels. LSM showed higher population growth rate than SSM at lower algal density (0.5 × 106 cells/mL) and higher Moina densities (0.3 and 0.9 ind./mL), which suggested that LSM could be more effective to defend M. macrocopa. Three-way analysis of variance showed no significant effects of algal density on population growth rate of K. tropica, but interaction between algal density and M. macrocopa density significantly affected its population growth rate.
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