Performance and mechanism of pilot-scale carbon fibers enhanced ecological floating beds for urban tail water treatment in optimized ecological floating beds water surface coverage.

A pilot-scale carbon fibers enhanced ecological floating beds (CF-EFBs) was constructed. Compared to EFBs without carbon fibers enhancement, CF-EFBs have the better removal of total inorganic nitrogen (TIN), total phosphorus (TP), and chemical oxygen demand (COD), the removal efficiencies were 3.19, 3.49, and 2.74 times higher than EFBs. Throughout the pilot test (under three different coverage rates), the concentrations of COD, TIN and TP of effluent were 18.11 ± 4.52 mgL-1, 1.95 ± 0.92 mgL-1 and 0.13 ± 0.08 mgL-1. Meanwhile, the average removal of TIN, TP and COD from tailwater was 0.96 gm-2d-1, 0.07 gm-2d-1 and 2.37 gm-2d-1 respectively. When the coverage was 30 %, the CF-EFBs had better nitrogen removal effectiveness (TIN purification ability of 1.49 gm-2d-1). The enrichment of denitrifying bacteria, such as Aridibacter, Nitrospira, Povalibacter, and Phaeodactylibacter increased denitrification efficiency. These results verified the feasibility of CF-EFBs in tailwater treatment at pilot-scale, which was of great significance for the practical application of CF-EFBs.

Improving performance of pilot-scale ecological bed coupled with microbial electrochemical system for urban tail water treatment.

Recycling urban tail water for ecological base flow and landscape use offers a reliable solution for the problem of water resource shortage. But the long-term direct discharge of urban tail water can aggravate the eutrophication of surface water based on the present drainage standard of sewage plant. It is of great significance to develop low-cost and low-energy ecological technologies as transitional region between urban tail water and surface water. In this study, a pilot-scale ecological bed coupled with microbial electrochemical system (EB-MES) was established to treat urban tail water deeply. The system was operated for 96 days from June to September. Average TN removal efficiency in EB-MES under the condition of submerged plant coupled closed-circuit MES could reach 59.0 ± 16.6 %, which was 82.7 % and 38.1 % higher than that of open-circuit EB-MES and MES without plants, respectively. Microbial community structure testing indicated that multiple nitrogen metabolic mechanisms occurred in the system, including nitrification, electrode autotrophic denitrification, anammox, simultaneous nitrification and denitrification, and aerobic denitrification, which results in better denitrification efficiency under tail water. Our research provided a novel ecological technology with advantages of high-efficiency, low-energy and low-carbon and verified the feasibility in pilot scale for application in the advanced treatment of urban tail water.

Optical microfibers integrated with evanescent field triggered self-growing polymer nanofilms.

Hybrid optical fibers have been widely investigated in different architectures to build integrated fiber photonic devices and achieve various applications. Here we proposed and fabricated hybrid microfiber waveguides with self-growing polymer nanofilms on the surfaces of microfibers triggered by evanescent field of light for the first time. We have demonstrated the polymer nanofilm of ∼50 nm can be grown on the microfiber with length up to 15 mm. In addition, the roughness of nanofilm can be optimized by controlling the triggering laser power and exposure duration, and the total transmission loss of the fabricated hybrid microfiber is less than 2 dB within a wide wavelength range. The hybrid polymer nanofilm microfiber waveguides have been characterized and their relative humidity (RH) responses have also been tested, indicating a potential for RH sensing. Our fabrication method may also be extended to construct the hybrid microfibers with different functional photopolymer materials.

Reproductive stimulation and energy allocation variation of BDE-47 and its derivatives on Daphnia magna.

As endocrine disrupting chemical, 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) is widely distributed in water environment with a high detection rate. 6-hydroxy-2,2',4,4'-tetrabromodiphenyl ether (6-OH-BDE-47) and 6-methoxy-2,2',4,4'-tetrabromodiphenyl ether (6-MeO-BDE-47) are two main derivatives of BDE-47. To explore the aquatic risk of BDE-47 and its derivatives, the effects of them and their ternary mixture on the reproduction, growth, energy allocation, and neurological and antioxidant responses of Daphnia magna were monitoring during different exposure periods, i.e., daphnids exposed to compounds for 21 days or pre-exposed to compounds for 14 days and then recovered 7 days in clean water. In general, in 21-day test, reproductive parameters of exposed daphnids were significantly stimulated, and the growth and enzymatic activities of super oxidase dimutase (SOD), glutathione peroxidase (GPx) and acetylcholinesterase (AChE) were significantly depressed by the single- or mixture compounds. In (14 + 7)-day test, the levels of body length, number of living offspring per female and the enzyme activities recovered to some degree. However, after 7 days of recovery in pollution free medium, the reproductive parameters and enzymatic activities of D. magna were unable to restore control values. These results showed that D. magna has a tendency that the energy allocated to reproduction was greater than that to grow after exposure. The energy distribution of D. magna occurred autonomously after being exposed, which can make it better adapt to environmental changes. Moreover, based on the behavioral and enzymology indicators of D. magna, the spider chart's application in the characteristic analysis of function indicators of D. magna implied that SOD, GPx and AChE could become sensitive biomarkers for different exposure periods. Those findings enable us to better understand BDE-47 and metabolites, and are conducive to better take measures to solve the pressure it brings.

High-efficient subwavelength-scale optofluidic waveguides with tapered microstructured optical fibers.

Microstructured optical fibers (MOFs) have attracted intensive research interest in fiber-based optofluidics owing to their ability to have high-efficient light-microfluid interactions over a long distance. However, there lacks an exquisite design guidance for the utilization of MOFs in subwavelength-scale optofluidics. Here we propose a tapered hollow-core MOF structure with both light and fluid confined inside the central hole and investigate its optofluidic guiding properties by varying the diameter using the full vector finite element method. The basic optical modal properties, the effective sensitivity, and the nonlinearity characteristics are studied. Our miniature optofluidic waveguide achieves a maximum fraction of power inside the core at 99.7%, an ultra-small effective mode area of 0.38 µm2, an ultra-low confinement loss, and a controllable group velocity dispersion. It can serve as a promising platform in the subwavelength-scale optical devices for optical sensing and nonlinear optics.

Facile synthesis of AgNPs@SNCDs nanocomposites as a fluorescent 'turn on' sensor for detection of glutathione.

The present study illustrates the facile synthesis of silver nanoparticles capped with sulfur and nitrogen co-doped carbon dots (AgNPs@SNCDs) nanocomposites and their application towards the sensitive and selective detection of glutathione (GSH) using a spectrofluorimetry method. SNCDs were synthesized using solvothermal treatment of cysteamine hydrochloride and p-phenylenediamine. The as-fabricated SNCDs were then utilized as capping and stabilizing agents for the preparation of AgNPs@SNCDs nanocomposites using wet chemistry. The size of AgNPs@SNCDs nanocomposites was characterized to be ~37.58 nm or even larger aggregates. Particularly, the quenched fluorescence of AgNPs@SNCDs nanocomposites could be significantly restored upon addition of GSH, and the colour of its solution changed to some extent. The fluorescence intensity ratio of AgNPs@SNCDs nanocomposites at ~450 nm and 550 nm was directly proportional to the GSH concentration within the ranges 8.35-66.83 µM and 66.83-200.5 µM, and the detection limit was 0.52 µM. Furthermore various common organic molecules had no obvious interference in the detection mode. The proposed nanosensor was successfully applied for GSH assay in actual water samples.

In situ probing of the thermal treatment of h-BN towards exfoliation.

Two-dimensional (2D) hexagonal boron nitride (h-BN) is becoming increasingly interesting for wider engineering applications. Thermal exfoliation is being suggested as a facile technology to produce large quantities of 2D h-BN. Further optimization of the process requires fundamental understanding of the exfoliation mechanism, which is hardly realized by ex situ techniques. In this study, in situ synchrotron x-ray powder diffraction experiments are conducted while heat treating bulk h-BN up to 1273 K. During the heating process, linear expansion of c-axis is observed and the contraction of a-axis up to around 750 K is consistent with previous research. However, a changing behavior from contraction to expansion in a-axis direction is newly observed when heating over 750 K. With the consideration of previous thermally oxidation studies, a hypothesis of thermal assisted exfoliation with oxygen interstitial and substitution of nitrogen at high temperature is proposed.

Intelligent Drug Delivery Microparticles with Visual Stimuli-Responsive Structural Color Changes.

BACKGROUND: Particle-based drug delivery systems (DDSs) have a demonstrated value for drug discovery and development. However, some problems remain to be solved, such as limited stimuli, visual-monitoring. AIM: To develop an intelligent multicolor DDSs with both near-infrared (NIR) controlled release and macroscopic color changes. MATERIALS AND METHODS: Microparticles comprising GO/pNIPAM/PEGDA composite hydrogel inverse opal scaffolds, with dextran and calcium alginate hydrogel were synthesized using SCCBs as the template. The morphology of microparticle was observed under scanning electron microscopy, and FITC-dextran-derived green fluorescence images were determined using a confocal laser scanning microscope. During the drug release, FITC-dextran-derived green fluorescence images were captured using fluorescent inverted microscope. The relationship between the power of NIR and the drug release rate was obtained using the change in optical density (OD) values. Finally, the amount of drug released could be estimated quantitatively used the structural color or the reflection peak position. RESULTS: A fixed concentration 8% (v/v) of PEGDA and 4mg/mL of GO was chosen as the optimal concentration based on the balance between appropriate volume shrinkage and structure color. The FITC-dextran was uniformly encapsulated in the particles by using 0.2 wt% sodium alginate. The microcarriers shrank because of the photothermal response and the intrinsic fluorescence intensity of FITC-dextran in the microparticles gradually decreased at the same time, indicating drug release. With an increasing duration of NIR irradiation, the microparticles gradually shrank, the reflection peak shifted toward blue and the structural color changed from red to orange, yellow, green, cyan, and blue successively. The drug release quantity can be predicted by the structural color of microparticles. CONCLUSION: The multicolor microparticles have great potential in drug delivery systems because of its vivid reporting color, excellent photothermal effect, and the good stimuli responsivity.

Aggregation-Induced Emission Properties of Glutathione and L-Cysteine Capped CdS Quantum Dots and their Application as Zn(II) Probe.

Targeting to obtain better water solubility and stability and less aggregation-caused quenching effects of quantum dots, two kinds of thiol molecules, glutathione and L-cysteine, were firstly united to offer stabilizing ligands for aqueous synthesized CdS quantum dots, which exhibited sensitive aggregation-induced emission properties. Fluorescent intensity of the CdS quantum dots was enhanced about 5 folds by simple solvent exchange from water to 90 vol% PEG200. Restriction of intramolecular motions in an aggregate state was probably the main cause of the phenomenon. At the same time, fluorescent intensity of CdS quantum dots in the presence of zinc ions was able to be enhanced about 2.2 folds. Based on the researches, a handy metal enhanced fluorescent probe for detecting zinc ions was established. And the detection limit was 0.58 µmol/L. Zinc ions as a bridge among CdS quantum dots to form aggregates limited motions of CdS quantum dots to a certain extent and simultaneously enhanced their fluorescence emission intensities. Meanwhile, activation of surface states of CdS quantum dots also led to emission enhancement. Both of the two factors together contributed to the fluorescence enhancement and ultimately to the sensitivity to zinc ion sample detection.

Mechanism analysis for the process-dependent driven mode of NaHCO3 in algal antibiotic removal: efficiency, degradation pathway and metabolic response.

This work provided a comprehensive perspective to investigate the performance of NaHCO3-driving effect and mechanism including the antibiotic removal, degradation pathway and metabolites analysis, and the algal physiological response during the removal process. Cefuroxime sodium was selected as the target antibiotic. Our results showed that NaHCO3 did not facilitate self-decomposition of the target antibiotic, while drove the improvement on the removal capacity of every algal cell, which then attributed to the total removal efficiency. After 24 h, there was an improvement on the removal rate of the target antibiotic (from 10.21% to 92.89%) when NaHCO3 was added. The degradation pathway of the target antibiotic was confirmed by the formation of three main products (M1, M2 and M3), and the degradation process, that from M1 to M2 and M2 to M3, was accelerated by the existence of NaHCO3. Besides, a 4-stage model illustrated the relationship between NaHCO3 and antibiotic removal process. Moreover, algal culture that supplemented with NaHCO3 demonstrated a better growth capacity. A large increase in the content of chlorophyll a and a moderate increase in the activity of two carbon metabolic enzymes (RuBisCO and CA) might be viewed as a positive response of the algae during the NaHCO3-driving process.

MOF-Derived Cu2O/Cu Nanospheres Anchored in Nitrogen-Doped Hollow Porous Carbon Framework for Increasing the Selectivity and Activity of Electrochemical CO2-to-Formate Conversion.

Copper-based metal-organic frameworks (MOFs) and their derivatives have been used for CO2 electroreduction; however, they still have obvious drawbacks like poor selectivity and durability. Here, Cu_btc (btc = benzene-1,3,5-tricarboxylate)-derived Cu2O/Cu anchored in a nitrogen-doped porous carbon framework (Cu2O/Cu@NC) was prepared for CO2 electroreduction. Cu2O/Cu@NC-800 (carbonizing Cu_btc at 800 °C) produced formate and ethanol concurrently with an overpotential as low as ∼380 mV. However, it exhibited higher selectivity toward formate against ethanol, with the maximum formate faradaic efficiencies of 70.5% at -0.68 V vs a reversible hydrogen electrode (RHE), which was 1.79 and 1.84 times higher than that of Cu2O/Cu@NC-700 and Cu2O/Cu@NC-900. This superior performance remained stable for over 30 h. The enhancement in activity and selectivity was attributed to (i) a higher Cu content and well-dispersed Cu2O/Cu nanoparticles inside the carbon frameworks, which provided abundant active reaction sites, and (ii) a higher content of N doped into the Cu2O/Cu lattice to possibly facilitate *OCHO generation. These findings provided a convenient strategy to enhance the activity and selectivity of catalysts for efficient CO2 electroreduction.

The Loading of Luminescent Magnetic Nanocomposites Fe3O4@Polyaniline/Carbon Dots for Methotrexate and Its Release Behavior In Vitro.

In the present study we developed novel luminescent magnetic nanocomposites termed Fe3O4@polyaniline/carbon dots. First, Fe3O4 magnetic nanoparticles were prepared by the coprecipitation method. The nanoparticles were then coated with polyaniline using the in situ growth method to form Fe3O4@polyaniline nanohybrids, which were endowed with amino functional groups on the surface and avoided the aggregation of Fe3O4 nanoparticles. The X-ray diffraction pattern demonstrated that the crystalline phase of the Fe3O4 nanoparticles was an inverse spinel structure and was not changed in the Fe3O4@polyaniline nanohybrids. The saturation magnetization and the coercive force of the as-prepared Fe3O4@polyaniline nanohybrids measured by a vibrating sample magnetizer were 63.7 emu·g-1 and zero respectively, which indicated that the Fe3O4@polyaniline nanohybrids exhibited excellent superparamagnetism. The Fe3O4@polyaniline nanohybrids were conjugated with carbon dots, prepared from orange juice, via the amide bond between the amino groups on the surface of the Fe3O4@polyaniline nanohybrids and the carboxyl groups on the surface of carbon dots. The obtained luminescent magnetic nanocomposites Fe3O4@polyaniline/carbon dots showed good photoluminescent properties, which hinted that the nanocomposites have potential in drug tracing and magnetic targeted drug delivery. Finally, the anticancer drug methotrexate was loaded into the Fe3O4@polyaniline/carbon dots nanocomposites, forming a novel magnetic targeted drug delivery system. The results confirmed that the novel drug delivery system exhibited excellent drug-loading capability for methotrexate of ca. 70%, and emits strong fluorescence at the wavelength of 360 nm. An in vitro release experiment of the drug delivery system indicated that the cumulative release percentage of methotrexate was 17.2% in the phosphate-buffered saline (pH = 7.4) within 36 h.

High-throughput sequencing analysis of marine pioneer surface-biofilm bacteria communities on different PDMS-based coatings.

Marine biofilms, the attachment of marine microorganisms on artificial surfaces in natural seawater, play critical roles in the development of marine biofouling, which pave ways for the settlement and colonization of sessile invertebrate larvae. Despite the excellent microbe-inhibitory effect of polydimethylsiloxane (PDMS)-based coatings, marine bacteria could still attach to surfaces and form natural biofilms. However, there is little information available on the common structural features of pioneer surface-biofilm bacteria (PSB) communities on different PDMS-based coatings with regard to their compositions, distributions and diversity. Herein, the present study aims to explore the compositional and structural features of the PSB communities on different PDMS-based coatings using 16S rRNA gene amplicon sequencing in terms of the taxonomic structures at phylum, family and genus level. The results revealed the PSB communities on different PDMS-based coatings possessed high similarities in compositional, structural and diversity features, but varied greatly in relative abundance and distributions. Proteobacteria was the most diverse and overwhelming phylum in biofilms formed on all PDMS-based coatings, followed by Cyanobacteria. In addition, the decreased abundance of Proteobacteria and the increased abundance of Cyanobacteria on the carbon nanotubes (CNTs)-modifed PDMS composites (CPCs) may contribute to their differential anti-biofouling effect against the colonization of juvenile macrofoulers.

Inhibitory effects of CuInS2 and CdTe nanoparticles on macrophage cytokine production and phagocytosis in vitro.

Macrophages eliminate and destroy invading bacteria and contaminants by engulfing them or secreting cytokines that trigger downstream immune responses. Consequently, impairment of the phagocytic functions of macrophages and/or suppressing their cytokine secretion are dangerous to organisms that rely on immune protection. Accordingly, exposure to environmental nanoparticles (NPs) that display immunomodulatory properties are serious. In this work, two types of NPs, i.e., mild-toxicity CuInS2 NPs and high-toxicity CdTe NPs, were used to evaluate the effects of NP exposure for macrophages. Following incubation for 24 h, THP-1-derived macrophage viability was assessed using an MTT method after exposing the THP-1 cells to different concentrations of CuInS2 or CdTe NPs. Phagocytosis assays demonstrated that both CuInS2 and CdTe NPs impair phagocytic activity toward Staphylococcus aureus (S. aureus). After pretreatment with CuInS2 and CdTe NPs at 4 µmol/L, THP-1 macrophages exhibited decreases in phagocytic ratio from ca. 32.9% to ca. 18.5% and 18.7%, respectively. Since the zeta potentials of intact and weathered CuInS2 NPs were distributed over a wide range from positive to negative, large quantities of intact and weathered CuInS2 NPs bore sufficient positive charge on their surfaces to induce membrane depolarization, thus theoretically providing electrostatic forces between S. aureus and THP-1, which could induce downstream intracellular events that increase phagocytosis. However, real time polymerase chain reaction arrays revealed that transcription of the pro-inflammatory factors IL-1ß, IL-6, and TNF-α decreased while that of the anti-inflammatory factor IL-10 increased after treatment with CuInS2 NPs. Furthermore, transcription of TNF-α decreased while IL-10 increased after treatment with CdTe NPs. Thus, both kinds of NPs inhibited phagocytosis of S. aureus by THP-1 to some extent, confirming that immunosuppression can occur when macrophages are exposed to environmental NPs.

A novel cadmium-containing wastewater treatment method: Bio-immobilization by microalgae cell and their mechanism.

Heavy metal cadmium (Cd) has drawn tremendous comcern due to its rigorous environmental and health hazards. Herein, we have presented an efficient and economical strategy for the removal and recycling of hazardous Cd ions using microalgae cells as the bioreactors. Remarkably, the green bio-platform for the bioproduction of CdSe nanoparticles (NPs) was developed depending on their orderly regulated and sustainable cellular environment. The biofabricated CdSe NPs manifested favorable photoluminescence properties, and presented well monodispersed spherical morphology and certain crystallinity structure with mean size of smaller than 7 nm. Especially, the fluorescence "turn off" sensing system based on the CdSe NPs was established to detect Hg2+. The nanosensor enables the quantitative analyses of Hg2+ with a linear range of 0-2.0 µM and a detection limit of 0.021 µM. Furthermore, it was preliminarily speculated that the reducing biomolecules in the algae cells could be involved in the formation of CdSe NPs. This work not only provides new insights into the removal and recycling of hazardous Cd ions, but also brings a promising route for biosynthesis of CdSe NPs.

Urinary levels, composition profile and cumulative risk of bisphenols in preschool-aged children from Nanjing suburb, China.

Due to the extensive use in consumer products, the bisphenols (BPs) pollution in the environments has aggravated and people are frequently exposed to BPs. In this research, four BPs, i.e., bisphenol A (BPA), bisphenol F (BPF), bisphenol S (BPS) and bisphenol AF (BPAF), were determined in urine samples collected from Gaochun District preschool-age children and the concentrations, distribution profiles, potential sources and cumulative risk assessment of the target compounds were studied. Total concentrations of 4 BPs ranged from 2 to 3113.1 ng/L, with the average concentration of 648.6 ng/L. BPA was the predominant congener (accounting for 94%), followed by BPS. Correlation analysis indicated a negative relationship between BPA and BPAF (R = -0.273, p < 0.05). The estimated daily intakes suggested that young females were more sensitive to BPs. Moreover, the cumulative risk for hazard quotient (HQ) of BPA has been evaluated and the results showed that no high risk had occurred. It provided basic information on the occurrence and human exposure to urinary BPs of preschool aged children from Gaochun District.

Evaluation of the novel nanoparticle material - CdSe quantum dots on Chlorella pyrenoidosa and Scenedesmus obliquus: Concentration-time-dependent responses.

Quantum dots (QDs), as a kind of novel nanomaterial, have the extensive applications in various fields, inevitably leading to increasing risks for the ecological environment. The mobilization of cadmium including metal smelting and subsequent machining for multifarious applications has caused the release of cadmium element into the environment. In this study, we evaluated the potential toxicity of a novel nanoparticle material CdSe QDs, using two green algae Chlorella pyrenoidosa and Scenedesmus obliquus. The impact of CdSe QDs and cadmium ions on algae and the sensitivity of the two algae on target compounds were also considered and compared. Our results showed the algal growth rates and chlorophyll content decreased with increasing exposure concentrations and durations. Moreover, the glutathione levels were decreased while the activities of superoxide dismutase increased, exhibiting their pivotal functions in defeating toxic stress. The increment of malondialdehyde levels revealed that the stresses of CdSe QDs and cadmium ions were contributed to the occurrence of oxidative damage. Our study also indicated that the impact of CdSe QDs was stronger than that of cadmium nitrate and the algal response was also species-specific. In addition, the TEM photographs of the algal ultrastructure showed the presence of surface attachment and uptake of QDs.

CdSe quantum dots labeled Staphylococcus aureus for research studies of THP-1 derived macrophage phagocytic behavior.

A simple biological strategy to couple intracellular irrelated biochemical reactions of staphylococcus aureus CMCC 26003 (S. aureus) with inorganic metal ions to synthesize cadmium selenide quantum dots (CdSe QDs) was demonstrated. Correspondingly, S. aureus as living matrices are internally generated and labeled with fluorescent QDs by the smart strategy. Several key factors in the process of biosynthesis were systematically evaluated. At the same time, ultraviolet-visible (UV-Vis), photo-luminescence (PL), inverted fluorescence microscopy and transmission electron microscopy (TEM) were utilized to study the characters of the as produced CdSe QDs. In addition, cytotoxicity and photostability of the QDs containing bacteria were also tested and evaluated as a whole. The results showed that intracellular CdSe nanocrystals had successfully formed in S. aureus living cells, which were less toxic, highly fluorescent and photostable. These fluorescent S. aureus bacteria were next applied as invading pathogens as well as fluorescent bioprobes for exploring the phagocytic behavior of THP-1-derived macrophage. Results proved that internal CdSe QDs labeling had no significantly adverse effects compared with the kind of infection reference, fluorescein isothiocyanate (FITC) stained S. aureus pathogen. Assuredly, the methods presented here provide researchers with a useful option to analyze the behavior of S. aureus as a type of infectious pathogen, which would also help understand the complex interplay between host cells and the invading bacteria on molecular level.

Correlation between antibiotic-induced feeding depression and body size reduction in zooplankton (rotifer, Brachionus calyciflorus): Neural response and digestive enzyme inhibition.

The study analyzed the correlation between the antibiotic-induced feeding depression and body size reduction in rotifer, Brachionus calyciflorus, involving exposure, post-exposure and re-exposure periods. The filtration and ingestion rates of the rotifers were inhibited in these three exposure periods at any given concentration of the antibiotic sulfamethazine (SMZ). As food for rotifer, the cell size of the green algae was unchanged, which indicated that it could not drive feeding depression. Secondly, several corresponding physiological responses were considered. Reactive oxygen species (ROS) levels increased in the post-exposure and the re-exposure; acetylcholinesterase (AChE) activity was significantly decreased in the exposure and the re-exposure, whereas it was induced in the post-exposure. The activities of amylase and lipase were always inhibited in these three exposure periods. Additionally, significant decreases in lorica length, width and biovolume of rotifers occurred after the feeding depression. Statistical analysis indicated a positive correlation between the activity of the digestive enzyme and the body size. Our results demonstrated that SMZ could influence the neurotransmission, inhibit the activity of the digestive enzyme, and finally result in body size reduction. These results provided an integrated perspective on assessing the toxicity effects of antibiotic in non-lethal dosage on the feeding behavior of non-target aquatic organisms.