Non-target screening aims to obtain an overview of the sample constituents and identifies all the eligible peaks in the sample. The soil samples contaminated by electroplating wastewater usually contain a large amount of organic pollutants with high matrix interferences (Zhao 2013). In order to choose an effective sample extraction method, three commonly used extraction methods including accelerated solvent extraction (ASE), Soxhlet extraction, and microwave-assisted extraction (MAE) (Wang 2007, Rodriguez-Solana 2015, and Jurado-Sanchez 2013) have been compared based on the previous reports. Among these methods, ASE provides the best extraction efficiency for extracting most semi-volatile organic compounds in soil samples with short …show more content…
Stock solutions were prepared in isooctane, and then diluted into seven concentration levels, from 1 to 500 µg/L. The stock solution was kept at -18 °C until use.
The internal standard solution with a concentration of 100 μg/L was diluted from an Internal Standard Mix purchased from AccuStandard (New Haven, Connecticut, USA) and used to determine the concentration of target compounds by calculating the response factor, noting that the selected internal standards were stable and similar to the analytes and would not interfere with the sample components. The surrogate standard solution was prepared at 10 mg/L for nitrobenzene-d5 and p-terphenyl-d14 for performing the quality control function, since its recovery rate was used to evaluate the efficiency of the analytical method. The organic solvents, of analytical grade, were purchased from J&K scientific LTD (Beijing, China).
Sample information and Sample Preparation
In this study, three soil samples were chosen for the analysis and explanation of the whole workflow. Two soil samples were collected from a leaching basin (Boxing, Shandong Province, China), surrounded by two small electroplating factories and polluted by electroplating wastewater. Sample #1 and Sample #2 were taken from the top layer soil (0–20 cm) and middle layer soil (20–50 cm) of the leaching basin bottom using a soil
Perform the following with three 0.05g samples of unknown and the following solvents: methanol, water and toluene
The result was small white crystals, which were dry and had barely contained any moisture. The product was then dissolved in methylene chloride and dried with granular anhydrous sodium sulfate. The drying agent would have removed any water in the solution and presented a colorless solution. The solvent was evaporated and the product was collected; it had the appearance of small, white solids. Data Table 2 shows the results and calculations that were gathered after the completion of this experiment. A boiling point of the product was found to be 210℃. According to literature, the boiling of isoborneol should be 212℃. As a result, the product is most likely isoborneol. No errors had occurred during the course of the experiment, which is testified by the high yield of
The stock solutions were prepared using acetone, sodium nitroprusside and vanillin having 100 ppm as the fixed concentration. From the stock solutions, dilutions have been performed to obtain the different concentrations necessary to assert the detection limit of the test when using either sodium nitroprusside or vanillin. For acetone,
The procedural steps were used but quantities were reduced whilst maintaining the same ratios. 18.8 g of TEOS was dissolved in 13.3 g of TPAOH dropwise for 30 min whilst being stirred continuously. The solution was hydrolysed at 4 °C for 1 hour. A mixture of 1.28 g of TBOT and 4.2 g of IPA were dissolved dropwise for 1 hour in the resulting solution. The solution was hydrolysed further at 4 °C for 1 hour. The volume of the solution was marked on the flask to indicate the initial volume. The solution was heated to 85 °C for 5 hours to remove any alcohol from the solution. The loss in volume was replenished to the initial volume with distilled
Currently, the environmental pollution is becoming a significant issue which caused by factories waste and nuclear waste. This pollution has increased around the world since the wide application of nuclear energy in 20th century. The harmful substances in factories wastes like toxic materials can dissolve easily in water and this leads to negative effects on lives. There are many resources of these substances such as persistent organic pollutants (POPs), which contain hydrogen, carbon and chlorine, pesticides, ammonium and dioxins. According to Mole (2015) many researchers found that ammonium and iodide have high levels in many waste water sample in the New York and Arkansas. The most popular process used to remove toxic metals from wastewater
Sometimes the soil conditions necessary cannot be achieved in situ. In some situations, the temperature might be too cold for the microbes to work or the soil may be too impenetrable to allow the amendments to spread underground. In these situations, soil might be dug up and cleaned above ground (“ex situ”). The soil can then be heated/stirred/mixed with amendments to improve the surroundings. The mixing of the soil can sometimes cause evaporation of the contaminants before the microbes can consume them. To prevent the contamination of the air from the vapours, the soil can be mixed inside a special tank or building, where the vapours from the evaporation of the chemicals can be accumulated and treated. (EPA, 2015). To purify polluted groundwater in situ, wells can be created by drilling into the ground to pump some of the groundwater into tanks above ground. This is where the water can be mixed with the amendments before it is pumped back underground. The water that was just pumped back into the ground, allows the microbes to bioremediate the rest of the contaminated water that is underground. (EPA,
All chemicals used in this study are of analytical grade, Table 3.1 shows the chemicals used in the study and their manufacturing companies.
In the optimization of the LC conditions, Postigo, Lopez de Alda, and Barceló tested two different columns and three different mobile-phase compositions with varying flow rates (0.2, 0.3, and 0.4 mL/min). For SPE elution and LC separation, binary mobile phase consisting of acetonitrile and binary mobile phase consisting of methanol were tested. The mobile phase selected for analysis was gradient acetonitrile/water. Its flow rate was 0.3 mL/min.
Treatments of heavy metal contaminants from effluent discharged by industries are more complex than designing the treatment process. Bacopa Monnieri is one of the wetland plant used for the removal of heavy metal, lead (Pb) from the aquatic medium. Effluent was collected from the Lead acid battery waste treatment plant. It is standardized to 5, 10 and 15ppm to observe the uptake by plant. Effluent was categorized as Direct Effluent (DE), DE+Ethylenediaminetetraacetic acid (EDTA) and DE+Cow Dung Manure (CDM), where EDTA and CDM were used as a chelating agent to influence in accumulation rate and degradation rate. Concentration of Pb in soil, plant (root and shoots), and effluent had been done to calculate the degradation of Pb, Translocation factor (TF) and Bioconcentration factor (BCF). This experiment shows tremendous differences in wetland plant unlike the researches done in past. Results of the experiment were discussed below.
Soil properties are shown in Table 2.1. These soils had a loamy texture with different contents of clay, sand and silt. pH values ranged from 4.45 to 7.73. TC was in the range of 1.6 to 8.37 % without significant amounts of TN and TS detected. TOC varied between 1.48 and 8.37% whilst DOC showed a wide range from 106 to 400 mg kg-1. CEC values ranged from 2.9 to 17.9 cmol kg-1. Concentrations of Fe oxide, Al oxide, and Mn oxide were 0.28-12.49 g kg-1, 0.5-12.6 g kg-1 and 0.0252-0.302 g kg-1, respectively. Total concentrations of As and Cd in control and spiked soil after one-year aging were listed in Table S1 (Appendix 2). The difference between the spiked concentrations and measured ones may be due to the particle size (spiked soils were sieved to < 250 μm particle size was used for all measurements.
If there is any automobile industries and machine repair shops nearby then Petroleum products , PAHs, trichloroethylene, rubber products, metals like chromium , lead , molybdenum and used batteries will be dumped to the soil and the soil will be contaminated due to that.
The study will be performed under the OECD Principles of Good Laboratory Practice (GLP), as reviewed in 1997 (ENV/MC/CHEM (98)17). Regarding to the subject and the design of the study, the OECD Guidelines for the Testing of Chemicals (OECD Guideline 407, as adopted on 3rd October 2008) will also be followed.
Collected sample filtered and concentrated 100 times by solid-phase extraction (SPE). Concentration of selected five ECs found 100 µg L−1 each. After 100 min of reaction time (t30W), 75% of all five contaminants were degraded (up to 25 µg L−1 each) with 50
Based on the overview of the sample’s constituents, another filter condition was added to pick out the most abundant compounds in the soil samples. According to the
Soil forms an important asset of today’s urban and rural population. Crops growing on fertile soils are important for feeding the millions around the globe. Accidental oil spills from water bodies and industries contaminate the soil in its vicinity. Also, pollution due to pesticides and insecticides have increasingly demanded soil clean up and restoration. Often we lay more emphasis on the role of biotic agents in remediation/ biodegradation but forget the important role that some physical effects have on the remediation of soils. This can be more advantageous and often is more effective in contaminant removal than other chemical or biological processes. The potential for using such an approach is clear in the fact that such methods are currently being used at some Superfund sites throughout the United States. They have been proven