ABSTRACT
Anaerobically digested swine wastewater (ASW) purification by microalgae provides a promising strategy for nutrients recovery, biomass production and CO2 capture. However, the characteristics of ASW from different cleaning processes vary greatly. At present, the cultivation of microalgae in ASW from different manure cleaning processes is rarely investigated and compared. That may bring uncertainty for microalgae growth using different ASW in large-scale application. Thus, the ASW from three cleaning processes were tested for cultivating microalgae, including manure dry collection (I), water flushing (II) and water submerging processes (III). The characteristics of ASW from three manure cleaning processes varied greatly such as nutrient and heavy metals levels. High concentration of ammonia and copper in ASW significantly inhibited microalgae growth. Fortunately, the supply of high CO2 (10%) effectively alleviated negative influences, ensuring microalgal growth at low dilution ratio. The characteristics of three ASW resulted in significant differences in microalgae growth and biomass components. The maximal biomass production in optimal diluted ASW-I, II and III reached 1.46 g L-1, 2.19 g L-1 and 2.47 g L-1, respectively. The removal of organic compounds, ammonia and phosphorus by optimal microalgae growth in diluted ASW-I, II and III was 50.6%/94.2%/64.7%, 63.7%/82.3%/57.6% and 83.2%/91.7%/59.7%, respectively. The culture in diluted ASW-I, II and III obtained the highest lipids production of 12.1 mg L-1·d-1, 16.5 mg L-1·d-1 and 19.4 mg L-1·d-1, respectively. The analysis of lipids compositions revealed that the proportion of saturated fatty acids accounted for 36.4%, 32.4% and 27.9 % in optimal diluted ASW-I, II and III, as ideal raw materials for biodiesel production.
Subject(s)
Chlorophyceae , Environmental Pollutants , Microalgae , Scenedesmus , Animals , Swine , Wastewater , Biomass , Manure , Ammonia , Carbon Dioxide , Nitrogen , Fatty Acids , Biofuels , WaterABSTRACT
The microalgae culture in mixing sewage with different characteristics may significantly improve biomass production and nutrients recycling efficiency. In this study, three waste organic wastewater including molasses, alcohol and glycerol wastewater were mixed with anaerobic soybean wastewater as mediums for microalgae culture. The optimal mixture of molasses, alcohol and glycerol wastewater was at an initial carbon-nitrogen ratio of 7:1, 5:1 and 10:1, improving biomass production by 60.4%, 31.3% and 68.7%, respectively. The removal efficiencies of organics, ammonia nitrogen and phosphorus at optimal mixture were 54.8-62.4%, 79.5-99.1% and 49.3-61.5%, and the removal rates increased by 340-630%, 27.5-66.3% and 36.3-70.2% compared to the blank culture. In addition, the culture in mixed wastewater increased lipids contrast by 0.7-1.3 times, while achieving higher saturation in fatty acids. The results suggested that microalgae culture using mixed wastewater was a strategy for high biomass production and nutrients recycling efficiency.
Subject(s)
Microalgae , Scenedesmus , Wastewater , Glycine max , Anaerobiosis , Biomass , Glycerol , Nutrients , Nitrogen/analysis , Phosphorus , BiofuelsABSTRACT
Peracetic acid (PAA), as a new oxidant, has attracted increasing attention in the treatment of refractory organic pollution in sewage. In this study, the nano core-shell Co@NC catalyst was prepared via etching and used to activate PAA to degrade sulfamethoxazole (SMX) in sewage. The results indicated that the degradation rate of SMX reached 98%, and its reaction rate constant was 0.80 min-1 under optimal conditions (catalyst dosage=0.02 g·L-1, PAA concentration=0.12 mmol·L-1, pH=7, SMX concentration=10 µmol·L-1). With the increase in PAA concentration and core-shell Co@NC dosage, the degradation efficiency of SMX increased. The study found that the core-shell Co@NC/PAA system had the best degradation effect on SMX under near-neutral conditions (pH 6.0-8.0), and both acidic and alkaline environments were not conducive to SMX degradation. HCO3- and humic acid showed significant inhibition on the degradation of SMX, whereas Cl- showed weak inhibition. In addition, through a free radical quenching experiment and electron paramagnetic resonance (EPR) detection, acetoxy radical (CH3CO2CO3·) were the main active species for the degradation of organic pollutants in the system. Transformation products (TPs) of SMX were analyzed by U-HPLC-Q-Exactive Orbitrap HRMS, and a possible degradation path of SMX was proposed. At the same time, the catalyst recycling experiment showed that the nano core-shell Co@NC catalyst had good stability and reusability.
ABSTRACT
Anaerobic digestates were potential mediums for cultivating oleaginous microalgae, but their various components brought uncertainties for aglal growth and lipids production. In this study, three microalgae strains were tested to grow on four typical anaerobic digestates. The results showed that anaerobic food wastewater was an optimal medium for C. pyrenoidosa and S. obliquus culture (N. oleoabundanst cannot survive), achieving the highest biomass (2.15-2.32 g L-1) and lipids production (20.6-32.5 mg L-1·d-1). In contrast, three microalgae strains could grow suboptimally in anaerobic municipal (0.79-0.95 g L-1) and toilet (0.92-1.40 g L-1) wastewater, but showed poor performances in anaerobic swine wastewater. The growth of microalgae removed 40.9-63.4% of TOC, 83.7-96.3% of NH4+-N and 70.3-89.4% of TP in the three ADs. In addition, it was unfortunately found that the lipids content and saturation degree in fatty acids significantly decreased in ADs with sufficient nutrients. It suggests that some measures should be taken to balance biomass, lipids production and quality for cultivating microalgae in anaerobic digestates.
Subject(s)
Environmental Pollutants , Microalgae , Anaerobiosis , Animals , Biomass , Fatty Acids , Swine , WastewaterABSTRACT
BACKGROUND: This study is aimed to unravel the genetic factors associated with microRNA (miRNA) expression in regulating sex-determining region Y-box 2 (SOX2)-mediated cisplatin resistance in small-cell lung cancer (SCLC). METHODS: The relevance of SOX2 expression in SCLC was analyzed in a panel of SCLC cells by quantitative real-time PCR (qPCR) and western blot (WB). We selected DMS114 cell line, in which SOX2 was amplified via lentiviral vector-mediated transfection of the SOX2 genes and tested for the half-maximal inhibitory concentration (IC50 ) by MTS assay. High-throughput sequencing and screening of differentially expressed miRNAs between SOX2-overexpressing and normal control cells were performed. Finally, miRanda software was used to verify the miRNAs bound with SOX2 and qPCR was used to identify the expression of miRNAs which were binding with SOX2. RESULTS: Cisplatin-resistant SOX2-overexpressing DMS114 cell lines were successfully developed, showing a statistically significant increase in SOX2 expression by qPCR and WB. Our results showed a typically higher IC50 value in SOX2-overexpressing cells compared with the negative controls. The high-throughput sequencing analysis revealed that 68 miRNAs were upregulated and 24 miRNAs were downregulated in the SOX2-overexpressing cells. The 24 downregulated miRNAs were further verified. Of them, a cancer-related miRNA, hsa-miR-340-5p, showed a higher binding affinity with SOX2 in network regulation mapping, which was also found to be markedly downregulated under qPCR analysis. CONCLUSION: We demonstrated that downregulated expression of hsa-miR-340-5p may affect cisplatin resistance by mediating SOX2 expression in SCLC cells, which may provide a potential target for the therapy of chemoresistant SCLCs.
Subject(s)
Carcinoma, Non-Small-Cell Lung/genetics , Drug Resistance, Neoplasm , Lung Neoplasms/genetics , MicroRNAs/genetics , SOXB1 Transcription Factors/genetics , A549 Cells , Antineoplastic Agents/toxicity , Cisplatin/toxicity , Down-Regulation , Gene Expression Regulation, Neoplastic , Humans , Lung Neoplasms/metabolism , MicroRNAs/metabolism , SOXB1 Transcription Factors/metabolismABSTRACT
Natural astaxanthin mainly derives from a microalgae producer, Haematococcus pluvialis. The induction of nitrogen starvation and high light intensity is particularly significant for boosting astaxanthin production. However, the different responses to light intensity and nitrogen starvation needed to be analyzed for biomass growth and astaxanthin accumulation. The results showed that the highest level of astaxanthin production was achieved in nitrogen starvation, and was 1.64 times higher than the control group at 11 days. With regard to the optimization of light intensity utilization, it was at 200 µmo/m²/s under nitrogen starvation that the highest astaxanthin productivity per light intensity was achieved. In addition, both high light intensity and a nitrogen source had significant effects on multiple indicators. For example, high light intensity had a greater significant effect than a nitrogen source on biomass dry weight, astaxanthin yield and astaxanthin productivity; in contrast, nitrogen starvation was more beneficial for enhancing astaxanthin content per dry weight biomass. The data indicate that high light intensity synergizes with nitrogen starvation to stimulate the biosynthesis of astaxanthin.
Subject(s)
Chlorophyceae/metabolism , Chlorophyceae/radiation effects , Light , Nitrogen/metabolism , Photobioreactors/microbiology , Starvation , Biomass , Cell Culture Techniques/methods , Chlorophyceae/cytology , Chlorophyceae/growth & development , Culture Media/chemistry , Dose-Response Relationship, Radiation , Microalgae/metabolism , Photic Stimulation/methods , Radiation Dosage , Time Factors , Xanthophylls/biosynthesisABSTRACT
Alcohol wastewater (AW) as carbon source for enhancing Chlorella pyrenoidosa growth and lipid accumulation in anaerobically digested starch wastewater (ADSW) was performed in outdoor cultivation. The biomass and lipid production significantly increased while adding optimal amount of AW (AW/ADSW=1:15) during exponential phase. In comparison with blank ADSW culture, the optimal AW addition increased the biomass production, lipid content and productivity by 35.29%, 102.68% and 227.91%, respectively. However, AW addition caused severe bacterial contamination and the total bacterial increased by 4.62-fold. Simultaneously, the optimal consortia of microalgae/bacteria effectively removed nutrients from the wastewater, including 405.18±36.47mgCODCr/L/day, 49.15±5.54mgN/L/day and 6.72±1.24mgP/L/day.
Subject(s)
Chlorella , Lipids , Wastewater , Biomass , Carbon , Microalgae , StarchABSTRACT
Academics researchers and "citizen scientists" from 22 countries confirmed that yellow mealworms, the larvae of Tenebrio molitor Linnaeus, can survive by eating polystyrene (PS) foam. More detailed assessments of this capability for mealworms were carried out by12 sources: five from the USA, six from China, and one from Northern Ireland. All of these mealworms digested PS foam. PS mass decreased and depolymerization was observed, with appearance of lower molecular weight residuals and functional groups indicative of oxidative transformations in extracts from the frass (insect excrement). An addition of gentamycin (30â¯mgâ¯g-1), a bactericidal antibiotic, inhibited depolymerization, implicating the gut microbiome in the biodegradation process. Microbial community analyses demonstrated significant taxonomic shifts for mealworms fed diets of PS plus bran and PS alone. The results indicate that mealworms from diverse locations eat and metabolize PS and support the hypothesis that this capacity is independent of the geographic origin of the mealworms, and is likely ubiquitous to members of this species.
Subject(s)
Bacteria/metabolism , Biodegradation, Environmental , Coleoptera/metabolism , Gastrointestinal Microbiome/physiology , Larva/metabolism , Polystyrenes/metabolism , Animals , Anti-Bacterial Agents/pharmacology , Bacteria/drug effects , China , Coleoptera/growth & development , Gastrointestinal Microbiome/drug effects , Gentamicins/pharmacology , Larva/growth & developmentABSTRACT
A freshwater algae Chlorella pyrenoidosa was cultured outdoors using anaerobically digested activated sludge effluent. The effects of pH variations were evaluated. The coupled pH variations and free ammonia toxicity significantly affected the algal growth, lipids accumulation and contamination control during every season. The free ammonia toxicity at high pH levels actually inhibited the algal growth. Compared to an optimal algal growth at a pH of 5.7-6.5, biomass productivity at a high pH of 8.3-8.8 was reduced by 67.15±6.98%, 54.39±6.42% and 83.63±5.71% in the spring, fall and summer, respectively. When the pH rose above 9.1-9.6, algae were unable to grow in the wastewater. However, high pH levels reduced contamination (e.g., bacteria and microalgae grazers) and triggered lipids accumulation in algal cells. These findings suggest that pH control strategies are essential for this type of algal wastewater system, where ammonia is the dominant nitrogen source.
Subject(s)
Ammonia/chemistry , Anaerobiosis , Chlorella/growth & development , Sewage , Biomass , Esters , Fatty Acids/chemistry , Hydrogen-Ion Concentration , Kinetics , Lipids/chemistry , Microalgae/growth & development , Nitrogen/chemistry , Phosphorus/chemistry , Temperature , Wastewater/microbiologyABSTRACT
A freshwater green algae Chlorella pyrenoidosa (C. pyrenoidosa) was cultured in outdoors using the diluted anaerobically digested activated sludge (ADAS). The outdoors batch culture in every season showed that C. pyrenoidosa can grow normally under natural conditions in the diluted ADAS (STE/ADAS=1.5/1, 3/1 and 5/1, v/v). Seasonal changes of environmental conditions significantly affected biomass growth and nutrient removal. Optimal biomass growth and nutrient removal was achieved at STE/ADAS=1.5/1 during summer culture, harvesting a maximum biomass concentration of 1.97 ± 0.21 g/L, average biomass productivity of 291.52 ± 33.74 g/m(3)/day (maximum value of 573.10 ± 41.82) and average lipids productivity of 37.49 ± 5.26 g/m(3)/day (maximum value of 73.70 ± 9.75); simultaneously, the microalgae growth effectively removed nutrients from the wastewater, including 105.6 ± 17.1 mg CODCr/L/day, 36.8 ± 6.1mg N/L/day and 6.1 ± 1.1 mg P/L/day.
Subject(s)
Anaerobiosis/physiology , Biomass , Chlorella/growth & development , Sewage/microbiology , Batch Cell Culture Techniques , Lipids , Wastewater/analysisABSTRACT
Microalgae cultivation using wastewater might be a suitable approach to support sustainable large-scale biomass production. Its compelling characteristics included the recycling of nutrients and water resources, reducing carbon emissions and harvesting available biomass. In outdoor batch and continuous cultures, Chlorella pyrenoidosa completely adapted to anaerobic digested starch processing wastewater and was the dominant microorganism in the photobioreactor. However, seasonal changes of environmental conditions significantly influenced biomass growth and lipid production. The long-term outdoor operation demonstrated that the biomass concentration and productivity in continuous operations at different hydraulic retention times (HRTs) can be successfully predicted using the kinetic growth parameters obtained from the batch culture. A moderate HRT (4days) in the summer provided the best microalgae and lipid production and achieved relatively high biomass concentrations of 1.29-1.62g/L, biomass productivities of 342.6±12.8mg/L/d and lipids productivities of 43.37±7.43mg/L/d.
Subject(s)
Batch Cell Culture Techniques/methods , Bioreactors/microbiology , Chlorella/physiology , Starch/metabolism , Wastewater/microbiology , Anaerobiosis/physiology , Cell Proliferation/physiology , Cell Survival/physiology , Pilot ProjectsABSTRACT
Environmental pollution by emerging contaminants, e.g. pharmaceuticals, has become a matter of widespread concern in recent years. We investigated the membrane transport of diclofenac and its toxic effects on gene expression and the development of zebrafish embryos. The association of diclofenac with the embryos conformed to the general partition model at low concentration, the partition coefficient being 0.0033â ml per embryo. At high concentration, the interaction fitted the Freundlich model. Most of the diclofenac remained in the extracellular aqueous solution with less than 5% interacting with the embryo, about half of which was adsorbed on the membranes while the rest entered the cytoplasm. Concentrations of diclofenac over 10.13â µM were lethal to all the embryos, while 3.78â µM diclofenac was teratogenic. The development abnormalities at 4 day post treatment (dpt) include shorter body length, smaller eye, pericardial and body edema, lack of liver, intestine and circulation, muscle degeneration, and abnormal pigmentation. The portion of the diclofenac transferred into the embryo altered the expression of certain genes, e.g. down-regulation of Wnt3a and Gata4 and up-regulation of Wnt8a. The alteration of expression of such genes or the regulation of downstream genes could cause defects in the cardiovascular and nervous systems.
Subject(s)
Diclofenac/toxicity , Gene Expression Regulation/drug effects , Zebrafish/genetics , Animals , Anti-Inflammatory Agents, Non-Steroidal/toxicity , Ecotoxicology , Embryo, Nonmammalian/drug effects , Embryonic Development/drug effects , Embryonic Development/genetics , Environmental Exposure/adverse effects , Environmental Pollutants/toxicity , Time FactorsABSTRACT
Use of animal manure is a main source of veterinary pharmaceuticals (VPs) in soil and groundwater through a series of migration processes. The sorption-desorption and transport of four commonly used VPs including trimethoprim (TMP), sulfapyridine, sulfameter, and sulfadimethoxine were investigated in three soil layers taken from an agricultural field in Chongming Island China and two types of aqueous solution (0.01 M CaCl2 solution and wastewater treatment plant effluent). Results from sorption-desorption experiments showed that the sorption behavior of selected VPs conformed to the Freundlich isotherm equation. TMP exhibited higher distribution coefficients (K d = 6.73-9.21) than other sulfonamides (K d = 0.03-0.47), indicating a much stronger adsorption capacity of TMP. The percentage of desorption for TMP in a range of 8-12 % is not so high to be considered significant. Low pH (Subject(s)
Agriculture
, Anti-Bacterial Agents/analysis
, Soil Pollutants/analysis
, Soil/chemistry
, Sulfonamides/analysis
, Trimethoprim/analysis
, Adsorption
, Animals
, China
, Hydrogen-Ion Concentration
, Kinetics
, Manure
, Models, Chemical
ABSTRACT
A novel magnetic-molecularly imprinted polymer (MMIP) based on chitosan-Fe3O4 has been synthesized for fast separation of carbamazepine (CBZ) from water. During polymerization, the modified chitosan-Fe3O4 was used not only as supporter but also as functional monomer. The properties of obtained MMIP were characterized by scanning electron and transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectra, thermo-gravimetric analysis and so on. The sorption equilibrium data was well described by Freundlich isotherm model and the increase in the temperature generated an increase in the sorption amount, indicating endothermic nature of adsorption process. Sorption kinetics followed the pseudo-second-order model. The feasibility of selective sorption of CBZ from real water by the MMIP was analyzed by using spiked real water samples. The result showed that the sorption capacity of MMIP has no obvious decrease in different water samples whereas there was obvious decline in the sorption amount of the MNIP.
Subject(s)
Carbamazepine/isolation & purification , Chitosan/chemistry , Ferric Compounds/chemistry , Magnetics , Molecular Imprinting , Polymers/chemistry , Water Pollutants, Chemical/isolation & purification , Adsorption , Kinetics , Microscopy, Electron, Scanning , Microscopy, Electron, Transmission , Recycling , Temperature , ThermogravimetryABSTRACT
A novel double templates-molecularly imprinted polymer (MIP) was prepared by precipitation polymerization using carbamazepine (CBZ) and clofibric acid (CA) as the double templates molecular and 2-vinylpyridine as functional monomer. The equilibrium data of MIP was well described by the Freundlich isotherm model. Two kinetic models were adopted to describe the experimental data, and the pseudo second-order model well-described adsorption of CBZ and CA on the MIP. Adsorption experimental results showed that the MIP had good selectivity and adsorption capacity for CBZ and CA in the presence of competitive compounds compared with non-imprinted polymer, commercial powdered activated carbon, and C18 adsorbents. The feasibility of removing CBZ and CA from water by the MIP was demonstrated using tap water, lake water, and river water.
Subject(s)
Carbamazepine/chemistry , Clofibric Acid/chemistry , Water Pollutants, Chemical/chemistry , Water Purification/methods , Adsorption , Molecular Imprinting , Pyridines/chemistryABSTRACT
A novel multi-templates molecularly imprinted polymer (MIP), using acidic pharmaceuticals mixture (ibuprofen (IBP), naproxen (NPX), ketoprofen (KEP), diclofenac (DFC), and clofibric acid (CA)) as the template, was prepared as solid-phase extraction (SPE) material for the quantitative enrichment of acidic pharmaceuticals in environmental samples and off-line coupled with liquid chromatography-mass spectrometry (LC/MS/MS). Washing solvent was optimized in terms of kind and volume for removing the matrix constituents nonspecifically adsorbed on the MIP. When 1L of water sample spiked at 1µg/L was loaded onto the cartridge, the binding capacity of the MIP cartridge were 48.7µg/g for KEP, 60.7µg/g for NPX, 52µg/g for CA, 61.3µg/g for DFC and 60.7µg/g for IBP, respectively, which are higher than those of the commercial single template MIP in organic medium (e.g. toluene) reported in the literature. Recoveries of the five acidic pharmaceuticals extracted from 1L of real water samples such as lake water and wastewater spiked at 1µg/L were more than 95%. The recoveries of acidic pharmaceuticals extracted from 10-g sediment sample spiked at the 10ng/g level were in the range of 77.4-90.6%. To demonstrate the potential of the MIP obtained, a comparison with commercial C18 SPE cartridge was performed. Molecularly imprinted solid-phase extraction (MISPE) cartridge showed higher recoveries than commercial C18 SPE cartridge for acidic pharmaceuticals. These results showed the suitability of the MISPE method for the selective extraction of a group of structurally related compounds such as acidic pharmaceuticals.
Subject(s)
Acids/isolation & purification , Geologic Sediments/analysis , Molecular Imprinting , Pharmaceutical Preparations/isolation & purification , Solid Phase Extraction/methods , Water Pollutants, Chemical/isolation & purification , Adsorption , Chromatography, Liquid , Lakes/analysis , Polymers/chemistry , Sensitivity and Specificity , Sewage/analysisABSTRACT
Degradation of carbamazepine (CBZ) using ultraviolet (UV), UV/H2O2, Fenton, UV/Fenton and photocatalytic oxidation with TiO2 (UV/TiO2) was studied in deionized water. The five different oxidation processes were compared for the removal kinetics of CBZ. The results showed that all the processes followed pseudo-first-order kinetics. The direct photolysis (UV alone) was found to be less effective than UV/H2O2 oxidation for the degradation of CBZ. An approximate 20% increase in the CBZ removal efficiency occurred with the UV/Fenton reaction as compared with the Fenton oxidation. In the UV/TiO2 system, the kinetics of CBZ degradation in the presence of different concentrations of TiO2 followed the pseudo-first order degradation, which was consistent with the Langmuir-Hinshelwood (L-H) model. On a time basis, the degradation efficiencies ofCBZ were in the following order: UV/Fenton (86.9% +/- 1.7%) > UV/TiO2 (70.4% +/- 4.2%) > Fenton (67.8% +/- 2.6%) > UV/H2O2 (40.65 +/- 5.1%) > UV (12.2% +/- 1.4%). However, the lowest cost was obtained with the Fenton process.
Subject(s)
Carbamazepine/chemistry , Water Pollutants, Chemical/chemistry , Carbamazepine/radiation effects , Hydrogen Peroxide , Iron , Kinetics , Oxidation-Reduction , Photosensitizing Agents , Titanium , Ultraviolet Rays , Water Pollutants, Chemical/radiation effectsABSTRACT
The increased application of nanomaterials has raised the level of public concern regarding possible toxicities caused by exposure to nanostructures. The interactions of nanosized hydroxyapatite (HA) with cytochrome c and hemoglobin were investigated by zeta-potential, UV-vis, fluorescence and circular dichroism. The experimental results indicated that the interactions were formed via charge attraction and hydrogen bond and obeyed Langmuir adsorption isotherm. The two functional proteins bridged between HA particles to aggregate into the coralloid form, where change of the secondary structure of proteins occurred. From effects of nanosized HA, SiO(2) and TiO(2) particles on the zebrafish embryos development, they were adsorbed on the membrane surface confirmed by the electronic scanning microscopy. Nano-HA aggregated into the biggest particles around the membrane protein and then caused a little toxicity to development of zebrafish embryos. The SiO(2) particles were distributed throughout the outer surface and caused jam of membrane passage, delay of the hatching time and axial malformation. Maybe owing to the oxygen free radical activity, TiO(2) caused some serious deformity characters in the cardiovascular system.
Subject(s)
Durapatite/metabolism , Durapatite/toxicity , Embryo, Nonmammalian/drug effects , Embryo, Nonmammalian/physiology , Embryonic Development/drug effects , Zebrafish Proteins/metabolism , Zebrafish/embryology , Adsorption , Animals , Cytochromes c/metabolism , Durapatite/chemistry , Hydrogen-Ion Concentration , Larva/drug effects , Nanostructures/toxicity , Osmolar Concentration , Protein Binding , Silicon Dioxide/chemistry , Silicon Dioxide/toxicity , Temperature , Titanium/chemistry , Titanium/toxicity , Zebrafish/metabolism , Zebrafish Proteins/chemistryABSTRACT
A solid-phase extraction (SPE)-high performance liquid chromatography (HPLC) method has been developed for simultaneous determination of 10 sulfonamide antibiotics in water. The analytes were first enriched and purified through a PEP solid-phase extraction column, and eluted with acetonitrile-dichloromethane solution (2: 1, V/V), then detected by a HPLC with a UV detector. The detection wavelength was 268 nm and the column temperature was 33 degrees C, using gradient elution process with acetonitrile - 0.4% acetic acid/water (V/V) as the mobile phase to achieve baseline separations of these 10 analytes. The linearity range was 10 - 2 000 microg x L(-1). The recovery ranges of standard addition for deionized water and real water samples were 73.4% - 95.6% and 70.2% - 92.5%, respectively (except for sulfonamide, were 8.5% and 8.0%). The limit of detection was 1.42-7.25 ng x L(-1). Application of this method for parts of Huangpu River in Shanghai, surface water and groundwater in Chongming Island showed that sulfonamide antibiotics were detected in different frequencies in different aqueous environments, with the concentration range of 13.3 - 241.5 ng x L(-1), proving this method is easy, rapid, sensitive and efficient to meet the needs of actual work.
Subject(s)
Anti-Bacterial Agents/analysis , Chromatography, High Pressure Liquid/methods , Sulfonamides/analysis , Water Pollutants, Chemical/analysis , Anti-Bacterial Agents/classification , China , Groundwater/analysis , Rivers , Sensitivity and Specificity , Solid Phase Extraction , Sulfonamides/classificationABSTRACT
The effect of ammonia inhibition was evaluated during the enhanced anaerobic treatment of digested effluent from a 700m(3) chicken-manure continuous stirred tank reactor (CSTR). A 12.3L internal circulation (IC) reactor inoculated with an anaerobic granular sludge and operated at 35±1°C was employed for the investigation. With a corresponding organic loading rate of 1.5-3.5kg-COD/m(3)d over a hydraulic retention time of 1.5d, a maximum volumetric biogas production rate of 1.2m(3)/m(3)d and TCOD (total COD) removal efficiency ranging from 70% to 80% was achieved. However, the continual increase in the influent TAN content led to ammonia inhibition in the methanogenesis system. The SCOD/TAN (soluble COD/total ammonia nitrogen) ratio was presented to be the key controlling factor for the anaerobic treatment of semi-digested chicken manure, and further validation through shock loading and ammonia inhibition experiments was conducted. The threshold value of the SCOD/TAN ratio was determined to be 2.4 (corresponding to a TAN of 1250mg/L) at an influent pH of 8.5-9.