Name: a complete method for evaluating the performance of photocatalysts for the degradation of antibiotics in environmental remediation
Uploaded: 2022-10-06T14:10:00
Description: Watch this Scientific Journal Video about A Complete Method for Evaluating the Performance of Photocatalysts for the Degradation of Antibiotics in Environmental Remediation at JoVE.com

This work was supported by the National Natural Science Foundation of China (21606180), and the Natural Science Basic Research Program of Shaanxi (Program No. 2019JM-589).

1. Preparation of the BrSubPc
NOTE: The BrSubPc sample was prepared according to a previously published work36. The reaction is carried out in a double-row tube vacuum line system, and the reaction process is strictly controlled under water-free and oxygen-free conditions.
<ol>
	<li>Pre-treatment of raw materials
	<ol>
		<li>Weigh 2 g of o-dicyanobenzene, dry it in a vacuum oven for 24 h, take it out and then grind it carefully in an agate mortar.</li...

In this paper, we present a complete methodology for evaluating the catalytic performance of photocatalytic materials, including the preparation of catalysts, the investigation of factors affecting photocatalysis, and the performance of catalyst recycling. This evaluation method is universal and applicable to all photocatalytic material performance evaluations.
In terms of material preparation methods, many schemes have been reported for the preparation of rhombic dodecahedral Ag3PO...

Tetracyclines (TCs) are common antibiotics that provide effective protection against bacterial infections and are widely used in animal husbandry, aquaculture, and disease prevention1,2. They are widely distributed in water due to their overuse and improper application in the past decades, as well as the discharge of industrial wastewater3. This has caused severe environmental pollution and serious risks to human health; for example, the excessive presence of TCs in the aqueous environment can negatively affect microbial community distribution and bacterial resistance, leading to ecological imbalances, mainly due to the highly hydrophilic and bioaccumulative nature of antibiotics, as well as a certain level of bioactivity and stability4,5,6. Due to the hyper-stability of TC in the environment, it is difficult to break down naturally; therefore, many methods have been developed, including biological, physicochemical, and chemical treatments7,8,9. Biological treatments are highly efficient and low-cost10,11. However, because they are toxic to microorganisms, they do not effectively degrade and mineralize antibiotic molecules in water12. Although physicochemical methods can remove antibiotics from wastewater directly and quickly, this method only converts the antibiotic molecules from the liquid phase to the solid phase, does not completely degrade them, and is too costly13.
In contrast to conventional methods, semiconductor photocatalysis has been widely used for the degradation of pollutants in the past decades due to its efficient catalytic degradation properties14. For example, the noble metal-free magnetic FexMny catalyst of Li et al. achieved efficient photocatalytic oxidation of a variety of antibiotic molecules in water without the use of any oxidant15. Yan et al. reported the in situ synthesis of lily-like NiCo2O4 nanosheets on waste biomass-derived carbon to achieve efficient photocatalytic removal of phenolic pollutants from water16. The technology relies on a semiconductor catalyst excited by light to generate photogenerated electrons (e-) and holes (h+)17. The photogenerated e- and h+ will be converted into superoxide anion radicals (O2-) or hydroxyl radicals (OH-) by reacting with absorbed O2 and H2O, and these oxidatively active species oxidize and decompose organic pollutant molecules in water into CO2 and H2O and other smaller organic molecules18,19,20. However, there is no unified field standard for photocatalyst performance evaluation. The evaluation of a material&#39;s photocatalytic performance should be investigated in terms of the catalyst preparation process, environmental conditions for optimal catalytic performance, catalyst recycling performance, etc. Ag3PO4, with its prominent photocatalytic ability, has triggered substantial concern in environmental remediation. This new photocatalyst achieves quantum efficiencies of up to 90 % at wavelengths greater than 420 nm, which is significantly higher than previously reported values21. However, the severe photo corrosion and unsatisfactory electron-hole separation rate of Ag3PO4 limit its wide application22. Therefore, various attempts have been made to overcome these drawbacks, such as shape optimization23, ion doping24, and heterostructure building25,26,27. In this paper, Ag3PO4 was modified using morphology control as well as heterojunction engineering. First, rhombic dodecahedral Ag3PO4 crystals with high surface energy were prepared by solvent phase synthesis at room temperature under ambient pressure. Then, organic supramolecular BrSubphthalocyanine (BrSubPc), which can act as both electron acceptor and electron donor, was self-assembled on the silver phosphate surface by the solvothermal method28,29,30,31,32,33,34,35. The photocatalytic performance of the prepared materials was evaluated by investigating the effect of different environmental factors on the photocatalytic performance of the prepared samples to degrade trace amounts of tetracycline in water. This paper provides a reference for the systematic evaluation of the photocatalytic performance of the materials, which is of significance for the future development of photocatalytic materials for practical applications in environmental remediation.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>300 W xenon lamp</td>
			<td>CeauLight</td>
			<td>CEL-HXF300</td>
			<td></td>
		</tr>
		<tr>
			<td>AgNO3</td>
			<td>Aladdin Reagent (Shanghai) Co., Ltd.</td>
			<td>7783-99-5</td>
			<td></td>
		</tr>
		<tr>
			<td>Air Pump</td>
			<td>Samson Group Co.</td>
			<td>ACO-001</td>
			<td></td>
		</tr>
		<tr>
			<td>BBr3</td>
			<td>Bailingwei Technology Co., Ltd.</td>
			<td>10294-33-4</td>
			<td></td>
		</tr>
		<tr>
			<td>Constant temperature circulating water bath</td>
			<td>Beijing Changliu Scientific Instruments Co.</td>
			<td>HX-105</td>
			<td></td>
		</tr>
		<tr>
			<td>Dichloromethane</td>
			<td>Tianjin Kemiou Chemical Reagent Co., Ltd.</td>
			<td>75-09-2</td>
			<td></td>
		</tr>
		<tr>
			<td>Ethanol</td>
			<td>Tianjin Fuyu Fine Chemical Co., Ltd.</td>
			<td>64-17-5</td>
			<td></td>
		</tr>
		<tr>
			<td>Fourier-transform infrared</td>
			<td>Bruker</td>
			<td>Vector002</td>
			<td></td>
		</tr>
		<tr>
			<td>Hexane</td>
			<td>Tianjin Kemiou Chemical Reagent Co., Ltd.</td>
			<td>110-54-3</td>
			<td></td>
		</tr>
		<tr>
			<td>HNO3</td>
			<td>Aladdin Reagent (Shanghai) Co., Ltd.</td>
			<td>7697-37-2</td>
			<td></td>
		</tr>
		<tr>
			<td>ICP-OES</td>
			<td>Aglient</td>
			<td>5110</td>
			<td></td>
		</tr>
		<tr>
			<td>K2HPO4</td>
			<td>Aladdin Reagent (Shanghai) Co., Ltd.</td>
			<td>16788-57-1</td>
			<td></td>
		</tr>
		<tr>
			<td>Magnesium Sulfate</td>
			<td>Tianjin Kemiou Chemical Reagent Co., Ltd.</td>
			<td>10034-99-8</td>
			<td></td>
		</tr>
		<tr>
			<td>Methanol</td>
			<td>Tianjin Kemiou Chemical Reagent Co., Ltd.</td>
			<td>67-56-1</td>
			<td></td>
		</tr>
		<tr>
			<td>NaOH</td>
			<td>Aladdin Reagent (Shanghai) Co., Ltd.</td>
			<td>1310-73-2</td>
			<td></td>
		</tr>
		<tr>
			<td>NH4NO3</td>
			<td>Sinopharm Group Chemical Reagent Co., Ltd.</td>
			<td>6484-52-2</td>
			<td></td>
		</tr>
		<tr>
			<td>o-dichlorobenzene</td>
			<td>Tianjin Fuyu Fine Chemical Co., Ltd.</td>
			<td>95-50-1</td>
			<td></td>
		</tr>
		<tr>
			<td>o-dicyanobenzene</td>
			<td>Sinopharm Group Chemical Reagent Co., Ltd.</td>
			<td>91-15-6</td>
			<td></td>
		</tr>
		<tr>
			<td>Scanning electron microscopy</td>
			<td>JEOL</td>
			<td>JSM-6390</td>
			<td></td>
		</tr>
		<tr>
			<td>Trichloromethane</td>
			<td>Tianjin Kemiou Chemical Reagent Co., Ltd.</td>
			<td>67-66-3</td>
			<td></td>
		</tr>
		<tr>
			<td>Ultraviolet-visible Spectrophotometer</td>
			<td>Shimadzu</td>
			<td>UV-3600</td>
			<td></td>
		</tr>
		<tr>
			<td>X-ray diffractometer</td>
			<td>Rigaku</td>
			<td>D/max-IIIA</td>
			<td></td>
		</tr>
	</tbody>
</table>

a complete method for evaluating the performance of photocatalysts for the degradation of antibiotics in environmental remediation

Various antibiotics such as tetracycline, aureomycin, amoxicillin, and levofloxacin are found in large quantities in groundwater and soil systems, potentially leading to the development of resistant and multi-drug resistant bacteria, posing a threat to humans, animals, and environmental systems. Photocatalytic technology has attracted keen interest due to its rapid and stable treatment and direct use of solar energy. However, most studies evaluating the performance of semiconductor catalysts for the photocatalytic degradation of organic pollutants in water are currently incomplete. In this paper, a complete experimental protocol is designed to comprehensively evaluate the photocatalytic performance of semiconductor catalysts. Herein, rhombic dodecahedral silver phosphate was prepared by a simple solvent phase synthesis method at room temperature and atmospheric pressure. BrSubphthalocyanine/Ag3PO4 heterojunction materials were prepared by the solvothermal method. The catalytic performance of as-prepared materials for the degradation of tetracycline was evaluated by studying different influencing factors such as catalyst dosage, temperature, pH, and anions at atmospheric pressure using a 300 W xenon lamp as a simulated solar light source and a light intensity of 350 mW/cm2. Compared with the first cycle, the constructed BrSubphthalocyanine/Ag3PO4 maintained 82.0% of the original photocatalytic activity after five photocatalytic cycles, while the pristine Ag3PO4 maintained only 28.6%. The stability of silver phosphate samples was further tested by a five-cycle experiment. This paper provides a complete process for evaluating the catalytic performance of semiconductor catalysts in the laboratory for the development of semiconductor catalysts with potential for practical applications.

The rhombic dodecahedron Ag3PO4 was successfully synthesized using this solvent phase synthesis method. This is confirmed by the SEM images shown in Figure 1A,B. According to the SEM analysis, the average diameter of the rhombic dodecahedral structure was found to be between 2-3 &#181;m. The pristine BrSubPc microcrystals show a large irregular flake structure (Figure 1C). In the composite sample, the titanium dioxide still...

Watch this Scientific Journal Video about A Complete Method for Evaluating the Performance of Photocatalysts for the Degradation of Antibiotics in Environmental Remediation at JoVE.com

A Complete Method for Evaluating the Performance of Photocatalysts for the Degradation of Antibiotics in Environmental Remediation

Presented here is a protocol to explore a universal set of experimental procedures for comprehensive laboratory evaluation of photocatalysts in the field of environmental purification, using the example of photocatalytic removal of antibiotic organic pollutant molecules from water by phthalocyanine sensitized silver phosphate composites.

Various antibiotics such as tetracycline, aureomycin, amoxicillin, and levofloxacin are found in large quantities in groundwater and soil systems, ...

This paper provides a complete process for evaluating the catalytic performance of semiconductor catalysts in the laboratory to develop semiconductor catalysts with potential for practical applications. The advantage of this technique is that the photocatalytic performance of semiconductor catalysts can be evaluated in the laboratory in a more comprehensive manner. Demonstrating the procedure will be Bing Wang, a PhD student from the laboratory of Zhuo Li.And XuXia Zhang, LeCheng Li, MengTing Ji, Zheng Zheng, ChuanHui Shi, master students from the laboratory of Zhuo Li.To begin, prepare the reaction solution by dissolving six grams of ammonium nitrate in 200 milliliters of deionized water and treat with ultrasonic waves at 40 kilohertz frequency, 300 watt power for five minutes in one cycle to dissolve it completely then put it into a 500 milliliter volumetric flask to fix the volume.Add 2, 526 milliliters of deionized water to a beaker and then add 180 milliliters of ammonium nitrate solution, 54 milliliters of sodium hydroxide solution, and 120 milliliter of silver nitrate solutions sequentially to the beaker. Stir the solution vigorously for 10 minutes to prepare the diammine silver one complex. Finally, add 120 milliliters of potassium hydrogen phosphate solution to the complex and stir for five minutes.After the color of the solution changes from colorless to light yellow the precipitate obtained is silver phosphate rhombic dodecahedral. Separate the resulting precipitate by centrifugation at 7, 155 point 5G for 10 minutes at room temperature. Subsequently, centrifuge at three times with 50 milliliters of deionized water in the same conditions.Store the rhombic dodecahedral silver phosphate at room temperature in a dry environment away from light. Dissolved 5.77 milligrams of bromine subphthalocyanine in 50 milliliters of ethanol in a glass beaker and dissolve completely by sonication at 40 kilohertz frequency 300 watt power in one cycle for 30 minutes at room temperature. Then add 144.25 milligrams of silver phosphate to the above solution and sonicate at 40 kilohertz frequency, 300 watt power in one cycle for 30 minutes at room temperature.Stir the above solution in an 80 degrees Celsius water bath to allow complete evaporation of the ethanol. Dry the resulting brownish yellow powder overnight in an oven at 60 degrees Celsius and name the prepared sample as bromine subphthalocyanine silver phosphate For the test solution, 10 milligrams of tetracycline were dissolved in 500 milliliters of distilled water to obtain a 20 PPM solution. Then transfer 50 milliliters of the test tetracycline solution to a glass photocatalytic reactor.Stir the solution thoroughly with a magnetic stir at 1000 rpm, and maintain the temperature at 25 degrees Celsius. Then turn the air pump switch on and add the air to the solution at a rate of 100 milliliters per minute to obtain air saturation. Add 50 milligrams of the prepared photo catalyst to the test solution to reach a concentration of one gram per liter.Take the first sample immediately using a glass syringe. After stirring for 30 minutes in the dark, take the second sample and turn on the light source After a radiation for different time intervals, filter all the extracted samples through a 0.22 micrometer nylon membrane to remove solid particles before analysis. Store the filtered samples away from light in five milliliters centrifuge tubes until analysis.Measure the concentration of tetracycline with a UV visible spectrophotometer at 356 nanometers and evaluate the photocatalytic effect by the degradation rate as described in the manuscript. The SEM analysis shows that the average diameter of the rhombic dodecahedral structure was found to be between two to three micrometers, while bromine subphthalocyanine microcrystals show a large irregular flake structure. The photocatalytic activity of silver phosphate showed only 72.86%while bromine subphthalocyanine silver phosphate demonstrated 94.54%degradation of tetracycline after 30 minutes of visible light to radiation.The degradation rate constant by composites was 1.69 times higher than that of the silver phosphate. After five cycles, the composite showed a high tetracycline removal rate of 77.5%However, it decreased from 72.86%to 20.84%by silver phosphate. The XRD analysis of the composite showed that the peaks of the cycled samples did not change compared with the original samples, indicating good stability of the composite.Photocatalytic degradation shows that the absorption and removal of tetracycline increased as the photocatalyst concentration in the reaction solution increased. The effect of pH on the photocatalytic degradation of the composite material to remove tetracycline was slightly reduced in acidic solutions while more attenuated in neutral and alkaline solutions. The addition of anions had an inhibitory effect on the photocatalytic degradation of tetracycline, but the degradation rate was not overly affected.The effect of temperature on photocatalytic degradation for 30 minutes shows that the degradation rate of tetracycline gradually increased with the increase in temperature. Remember to turn on the circulating water switch to control the temperature at 25 degrees Celsius when performing the photocatalytic experiment.

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Environment

Physical, Chemical and Biological Characterization of Six Biochars Produced for the Remediation of Contaminated Sites

The physical and chemical properties of biochar vary based on feedstock sources and production conditions, making it possible to engineer biochars with specific functions (e.g. carbon sequestration, soil quality improvements, or contaminant sorption). In 2013, the International Biochar Initiative (IBI) made publically available their Standardized Product Definition and Product Testing Guidelines (Version 1.1) which set standards for physical and chemical characteristics for biochar. Six biochars made from three different feedstocks and at two temperatures were analyzed for characteristics related to their use as a soil amendment. The protocol describes analyses of the feedstocks and biochars and includes: cation exchange capacity (CEC), specific surface area (SSA), organic carbon (OC) and moisture percentage, pH, particle size distribution, and proximate and ultimate analysis. Also described in the protocol are the analyses of the feedstocks and biochars for contaminants including polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), metals and mercury as well as nutrients (phosphorous, nitrite and nitrate and ammonium as nitrogen). The protocol also includes the biological testing procedures, earthworm avoidance and germination assays. Based on the quality assurance / quality control (QA/QC) results of blanks, duplicates, standards and reference materials, all methods were determined adequate for use with biochar and feedstock materials. All biochars and feedstocks were well within the criterion set by the IBI and there were little differences among biochars, except in the case of the biochar produced from construction waste materials. This biochar (referred to as Old biochar) was determined to have elevated levels of arsenic, chromium, copper, and lead, and failed the earthworm avoidance and germination assays. Based on these results, Old biochar would not be appropriate for use as a soil amendment for carbon sequestration, substrate quality improvements or remediation.

Biochar is a carbon-rich material used as a soil amendment with the ability to sustainably sequester carbon, improve substrate quality and sorb contaminants. This protocol describes the 17 analytical methods used for the characterization of biochar, which is required prior to large scale implementation of these amendments in the environment.

The physical and chemical properties of biochar vary based on feedstock sources and production conditions, making it possible to engineer biochars with ...

A Whole Cell Bioreporter Approach to Assess Transport and Bioavailability of Organic Contaminants in Water Unsaturated Systems

Bioavailability of contaminants is a prerequisite for their effective biodegradation in soil. The average bulk concentration of a contaminant, however, is not an appropriate measure for its availability; bioavailability rather depends on the dynamic interplay of potential mass transfer (flux) of a compound to a microbial cell and the capacity of the latter to degrade the compound. In water-unsaturated parts of the soil, mycelia have been shown to overcome bioavailability limitations by actively transporting and mobilizing organic compounds over the range of centimeters. Whereas the extent of mycelia-based transport can be quantified easily by chemical means, verification of the contaminant-bioavailability to bacterial cells requires a biological method. Addressing this constraint, we chose the PAH fluorene (FLU) as a model compound and developed a water unsaturated model microcosm linking a spatially separated FLU point source and the FLU degrading bioreporter bacterium Burkholderia sartisoli RP037-mChe by a mycelial network of Pythium ultimum. Since the bioreporter expresses eGFP in response of the PAH flux to the cell, bacterial FLU exposure and degradation could be monitored directly in the microcosms via confocal laser scanning microscopy (CLSM). CLSM and image analyses revealed a significant increase of the eGFP expression in the presence of P. ultimum compared to controls without mycelia or FLU thus indicating FLU bioavailability to bacteria after mycelia-mediated transport. CLSM results were supported by chemical analyses in identical microcosms. The developed microcosm proved suitable to investigate contaminant bioavailability and to concomitantly visualize the involved bacteria-mycelial interactions.

A whole cell bioreporter assay with Burkholderia sartisoli RP037-mChe was developed to detect fractions of an organic contaminant (i.e., fluorene) available for bacterial degradation after active transport by mycelia bridging air-filled pores in a water unsaturated model system.

Bioavailability of contaminants is a prerequisite for their effective biodegradation in soil. The average bulk concentration of a contaminant, however, is ...

A Bending Test for Determining the Atterberg Plastic Limit in Soils

The thread rolling test is the most commonly used method to determine the plastic limit (PL) in soils. It has been widely criticized, because a considerable subjective judgment from the operator that carries out the test is involved during its performance, which may affect the final result significantly. Different alternative methods have been put forward, but they cannot compete with the standard rolling test in speed, simplicity and cost.
In an earlier study by the authors, a simple method with a simple device to determine the PL was presented (the &#34;thread bending test&#34; or simply &#34;bending test&#34;); this method allowed the PL to be obtained with minimal operator interference. In the present paper a version of the original bending test is shown. The experimental basis is the same as the original bending test: soil threads which are 3 mm in diameter and 52 mm long are bent until they start to crack, so that both the bending produced and its related moisture content are determined. However, this new version enables the calculation of PL from an equation, so it is not necessary to plot any curve or straight line to obtain this parameter and, in fact, the PL can be achieved with only one experimental point (but two experimental points are recommended).
The PL results obtained with this new version are very similar to those obtained through the original bending test and the standard rolling test by a highly experienced operator. Only in particular cases of high plasticity cohesive soils, there is a greater difference in the result. Despite this, the bending test works very well for all types of soil, both cohesive and very low plasticity soils, where the latter are the most difficult to test via the standard thread rolling method.

The traditional standardized test for determining the plastic limit in soils is performed by hand, and the result varies depending on the operator. An alternative method based on bending measurements is presented in this study. This allows the plastic limit to be obtained with a clear and objective criterion.

The thread rolling test is the most commonly used method to determine the plastic limit (PL) in soils. It has been widely criticized, because a ...

A Flow-through Exposure System for Evaluating Suspended Sediments Effects on Aquatic Life

This paper describes the Fish Larvae and Egg Exposure System (FLEES). The flow-through exposure system is used to investigate the effects of suspended sediment on various aquatic species and life stages in the laboratory by using pumps and automating delivery of sediment and water to simulate suspension of sediment. FLEES data are used to develop exposure-response curves between the effects on aquatic organisms and suspended sediment concentrations at the desired exposure duration. The effects data are used to evaluate management practices used to reduce the interactions between aquatic organisms and anthropogenic causes of suspended sediments. The FLEES is capable of generating total suspended solids (TSS) concentrations as low as 30 to as high as 800 mg/L, making this system an ideal choice for evaluating the effects of TSS resulting from many activities including simulating low ambient levels of TSS to evaluating sources of suspended sediments from dredging operations, vessel traffic, freshets, and storms.

A robust and flexible flow-through exposure system designed to maintain sediment in suspension is presented. The system is used to investigate the effects of suspended sediment on various aquatic species and life stages in the laboratory.

This paper describes the Fish Larvae and Egg Exposure System (FLEES). The flow-through exposure system is used to investigate the effects of suspended ...

Ecotoxicological Method with Marine Bacteria Vibrio anguillarum to Evaluate the Acute Toxicity of Environmental Contaminants

Bacteria are an important component of the ecosystem, and microbial community alterations can have a significant effect on biogeochemical cycling and food webs. Toxicity testing based on microorganisms are widely used because they are relatively quick, reproducible, cheap, and are not associated with ethical issues. Here, we describe an ecotoxicological method to evaluate the biological response of the marine bacterium Vibrio anguillarum. This method assesses the acute toxicity of chemical compounds, including new contaminants such as nanoparticles, as well as environmental samples. The endpoint is the reduction of bacterial culturability (i.e., the capability to replicate and form colonies) due to exposure to a toxicant. This reduction can be generally referred to as mortality. The test allows for the determination of the LC50, the concentration that causes a 50% decrease of bacteria actively replicating and forming colonies, after a 6 h exposure. The culturable bacteria are counted in terms of colony forming units (CFU), and the &#34;mortality&#34; is evaluated and compared to the control. In this work, the toxicity of copper sulphate (CuSO4) was evaluated. A clear dose-response relationship was observed, with a mean LC50 of 1.13 mg/L, after three independent tests. This protocol, compared to existing methods with microorganisms, is applicable in a wider range of salinity and has no limitations for colored/turbid samples. It uses saline solution as the exposure medium, avoiding any possible interferences of growth medium with the investigated contaminants. The LC50 calculation facilitates comparisons with other bioassays commonly applied to ecotoxicological assessments of the marine environment.

Ecotoxicological Method with Marine Bacteria Vibrio anguillarum to Evaluate the Acute Toxicity of Environmental Contaminants

This work describes a new protocol to assess the ecotoxicity of pollutants, including emerging contaminants such as nanomaterials, using the marine bacterium Vibrio anguillarum. This method allows for the determination of the LC50, or mortality, the concentration that causes a 50% decrease in bacteria culturability, after a 6 h exposure.

Bacteria are an important component of the ecosystem, and microbial community alterations can have a significant effect on biogeochemical cycling and food ...

Comparison of Scale in a Photosynthetic Reactor System for Algal Remediation of Wastewater

An experimental methodology is presented to compare the performance of two different sized reactors designed for wastewater treatment. In this study, ammonia removal, nitrogen removal and algal growth are compared over an 8-week period in paired sets of small (100 L) and large (1,000 L) reactors designed for algal remediation of landfill wastewater. Contents of the small and large scale reactors were mixed before the beginning of each weekly testing interval to maintain equivalent initial conditions across the two scales. System characteristics, including surface area to volume ratio, retention time, biomass density, and wastewater feed concentrations, can be adjusted to better equalize conditions occurring at both scales. During the short 8-week representative time period, starting ammonia and total nitrogen concentrations ranged from 3.1-14 mg NH3-N/L, and 8.1-20.1 mg N/L, respectively. The performance of the treatment system was evaluated based on its ability to remove ammonia and total nitrogen and to produce algal biomass. Mean &#177; standard deviation of ammonia removal, total nitrogen removal and biomass growth rates were 0.95&#177;0.3 mg NH3-N/L/day, 0.89&#177;0.3 mg N/L/day, and 0.02&#177;0.03 g biomass/L/day, respectively. All vessels showed a positive relationship between the initial ammonia concentration and ammonia removal rate (R2=0.76). Comparison of process efficiencies and production values measured in reactors of different scale may be useful in determining if lab-scale experimental data is appropriate for prediction of commercial-scale production values.

An experimental methodology is presented to compare the performance of small (100 L) and large (1,000 L) scale reactors designed for algae remediation of landfill wastewater. System characteristics, including surface area to volume ratio, retention time, biomass density, and wastewater feed concentrations, can be adjusted based on application.

An experimental methodology is presented to compare the performance of two different sized reactors designed for wastewater treatment. In this study, ...

Evaluating the Effect of Environmental Chemicals on Honey Bee Development from the Individual to Colony Level

The presence of pesticides in the beekeeping environment is one of the most serious problems that impacts the life of a honey bee. Pesticides can be brought back to the beehive after the bees have foraged on flowers that have been sprayed with pesticides. Pesticide contaminated food can be exchanged between workers which then feed larvae and therefore can potentially affect the development of honey bees. Thus, residual pesticides in the environment can become a chronic damaging factor to honey bee populations and gradually lead to colony collapse. In the presented protocol, honey bee feeding methods are described and applied to either an individual honey bee or to a colony. Here, the insect growth regulator (IGR) pyriproxyfen (PPN), which is widely used to control pest insects and is harmful to the development of honey bee larvae and pupae, is used as the pesticide. The presenting procedure can be applied to other potentially harmful chemicals or honeybee pathogens for further studies.

Herein we present a method to feed pesticide contaminated food to both an individual honey bee and a beehive colony. The procedure evaluates the pesticide effect on individual honey bees by in vivo feeding of basic larval diet and also on the natural condition of beehive colony.

The presence of pesticides in the beekeeping environment is one of the most serious problems that impacts the life of a honey bee. Pesticides can be ...

Extraction of Organochlorine Pesticides from Plastic Pellets and Plastic Type Analysis

Plastic resin pellets, categorized as microplastics (&#8804;5 mm in diameter), are small granules that can be unintentionally released to the environment during manufacturing and transport. Because of their environmental persistence, they are widely distributed in the oceans and on beaches all over the world. They can act as a vector of potentially toxic organic compounds (e.g., polychlorinated biphenyls) and might consequently negatively affect marine organisms. Their possible impacts along the food chain are not yet well understood. In order to assess the hazards associated with the occurrence of plastic pellets in the marine environment, it is necessary to develop methodologies that allow for rapid determination of associated organic contaminant levels. The present protocol describes the different steps required for sampling resin pellets, analyzing adsorbed organochlorine pesticides (OCPs) and identifying the plastic type. The focus is on the extraction of OCPs from plastic pellets by means of a pressurized fluid extractor (PFE) and on the polymer chemical analysis applying Fourier Transform-InfraRed (FT-IR) spectroscopy. The developed methodology focuses on 11 OCPs and related compounds, including dichlorodiphenyltrichloroethane (DDT) and its two main metabolites, lindane and two production isomers, as well as the two biologically active isomers of technical endosulfan. This protocol constitutes a simple and rapid alternative to existing methodology for evaluating the concentration of organic contaminants adsorbed on plastic pieces.

Microplastics act as vector of potentially toxic organic contaminants with unpredictable effects. This protocol describes an alternative methodology for assessing the levels of organochlorine pesticides adsorbed on plastic pellets and identifying the polymer chemical structure. The focus is on pressurized fluid extraction and attenuated total reflectance Fourier transform infrared spectroscopy.

Plastic resin pellets, categorized as microplastics (&#8804;5 mm in diameter), are small granules that can be unintentionally released to the environment ...

A Novel Method for the Pentosan Analysis Present in Jute Biomass and Its Conversion into Sugar Monomers Using Acidic Ionic Liquid

Recently, ionic liquids (ILs) are used for biomass valorization into valuable chemicals because of their remarkable properties such as thermal stability, lower vapor pressure, non-flammability, higher heat capacity, and tunable solubility and acidity. Here, we demonstrate a method for the synthesis of C5 sugars (xylose and arabinose) from the pentosan present in jute biomass in a one-pot process by utilizing a catalytic amount of Br&#248;nsted acidic 1-methyl-3-(3-sulfopropyl)-imidazolium hydrogen sulfate IL. The acidic IL is synthesized in the lab and characterized using NMR spectroscopic techniques for understanding its purity. The various properties of BAIL are measured such as acid strength, thermal and hydrothermal stability, which showed that the catalyst is stable at a higher temperature (250 &#176;C) and possesses very high acid strength (Ho 1.57). The acidic IL converts over 90% of pentosan into sugars and furfural. Hence, the presenting method in this study can also be employed for the evaluation of pentosan concentration in other kinds of lignocellulosic biomass.

We present a protocol for the synthesis of C5 sugars (xylose and arabinose) from a renewable non-edible lignocellulosic biomass (i.e., jute) with the presence of Br&#248;nsted acidic ionic liquids (BAILs) as the catalyst in water. The BAILs catalyst exhibited better catalytic performance than conventional mineral acid catalysts (H2SO4 and HCl).

Recently, ionic liquids (ILs) are used for biomass valorization into valuable chemicals because of their remarkable properties such as thermal stability, ...

Experimental Protocol for Examining Behavioral Response Profiles in Larval Fish: Application to the Neuro-stimulant Caffeine

Fish models and behaviors are increasingly used in the biomedical sciences; however, fish have long been the subject of ecological, physiological and toxicological studies. Using automated digital tracking platforms, recent efforts in neuropharmacology are leveraging larval fish locomotor behaviors to identify potential therapeutic targets for novel small molecules. Similar to these efforts, research in the environmental sciences and comparative pharmacology and toxicology is examining various behaviors of fish models as diagnostic tools in tiered evaluation of contaminants and real-time monitoring of surface waters for contaminant threats. Whereas the zebrafish is a popular larval fish model in the biomedical sciences, the fathead minnow is a common larval fish model in ecotoxicology. Unfortunately, fathead minnow larvae have received considerably less attention in behavioral studies. Here, we develop and demonstrate a behavioral profile protocol using caffeine as a model neurostimulant. Though photomotor responses of fathead minnows were occasionally affected by caffeine, zebrafish&#160;were markedly more sensitive for photomotor and locomotor endpoints, which responded at environmentally relevant levels. Future studies are needed to understand comparative behavioral sensitivity differences among fish with age and time of day, and to determine whether similar behavioral effects would occur in nature and be indicative of adverse outcomes at the individual or population levels of biological organization.

Here, we present a protocol to examine larval zebrafish and fathead minnow locomotor activities and photomotor responses (PMR) using an automated tracking software. When incorporated in common toxicology bioassays, analyses of these behaviors provide a diagnostic tool to examine chemical bioactivity. This protocol is described using caffeine, a model neurostimulant.

Fish models and behaviors are increasingly used in the biomedical sciences; however, fish have long been the subject of ecological, physiological and ...