scholarly journals Complexation Of Amino Acid With Cadmium And Its Application To Remove Cadmium From Contaminated Soil

2021 ◽  
Author(s):  
Wenbin Yao ◽  
Zhihui Yang ◽  
Lei Huang ◽  
Changqing Su
Keyword(s):  
Amino Acid ◽  
Contaminated Soil ◽  
Complex Stability ◽  
Bcr Sequential Extraction ◽  
Complex Stability Constant ◽  
Theory Calculation ◽  
Cd Removal ◽  
Reducible Fraction ◽  
Soil Batch ◽  
Complexation Ability

Abstract Low molecular organic acids, such as amino acid, play an important role in cadmium (Cd) mobility. However, its complexation ability with Cd was not well studied. The complexation structure of amino and cadmium was investigated by theory calculation based on B3ly/SDD and detecting by FTIR spectrum. The conformers were found to be [COc, COc] for fatty amino-cadmium and PheCd2+, [COc, COc, COs] for GluCd2+and ThrCd2+, respectively. The complex energy of these conformers was calculated in water phase by SMD model and the order of chelation energy was; PheCd2+> AlaCd2+ > LeuCd2+ > GluCd2+ > GlyCd2+ > ThrCd2+. All the dissolving energy of complexes was below zero, indicating these complexes was easily dissolved in water. In aqueous solution experiment, the Cd2+ concentration decreased with increasing amino acid concentration. The order of logβ (Complex stability constant) was: PheCd2+> AlaCd2+ > LeuCd2+ > GluCd2+ > GlyCd2+ > ThrCd2+, consisting with the order of calculated chelation energy. The Cd removal efficiency by Thr, Glu, Gly, Ala, Leu and Phe were 38.88%, 37.47%, 35.5%, 34.72%, 34.04% and 31.99%, respectively. From soil batch experiment, the total Cd in soil was decreased in present of amino acid with the concentration of Cd in water increased from 231.97 µg/L to 652.94-793.51 µg/L. The results of BCR sequential extraction showed that the Cd in acid soluble and reducible fraction sharply decreased. From all the results, the amino acid has potential to be used as a chelation to remedy the Cd contaminated soil.

Research on the Morphological of Lead and Zinc in the Smelting Slag

2015 ◽  
Vol 1088 ◽  
pp. 200-205
Author(s):  
Lin Yu ◽  
Dong Wei Li
Keyword(s):  
Heavy Metals ◽  
Sequential Extraction ◽  
Ecological Risk ◽  
Total Content ◽  
Residual Fraction ◽  
Bcr Sequential Extraction ◽  
Lead And Zinc ◽  
Smelting Slag ◽  
Reducible Fraction

In this paper analysed the forms of heavy metals (Zn Pb Cd and As) of the Smelting Slag for Lead and Zinc,using BCR sequential extraction. Different chemical morphological of heavy metals have different activity and harmfulness. Migration and Utilization of heavy metals were decided by the existent form of heavy metals in the soil,which influenced Bioactivity and Toxicity. The results show that the main forms of Zn and Cd are Oxidizable and Residual fraction, and Pb mainly occurred in Oxidizable and Reducible fraction. however, As mainly occurred in Residual fraction, which the percentage of reachs 99.56%. According to the percentage of fractions extracted in total content (As is 0.44%, Zn is 14.7%, Pb is 85.98%, Cd is 48.86%),the latent ecological risk of heavy metals varied in the descending order of,Pb Cd Zn and As.

Enhanced Electrokinetic Remediation of Cadmium (Cd)-Contaminated Soil With Interval Power breaking

2021 ◽  
Author(s):  
Zongping Cai ◽  
Yan Sun ◽  
Yanghong Deng ◽  
Xiaojie Zheng ◽  
Shuiyu Sun ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Power Supply ◽  
Contaminated Soil ◽  
Laboratory Experiments ◽  
Electrokinetic Remediation ◽  
Charged Species ◽  
Continuous Power ◽  
Cd Removal ◽  
Cd Species ◽  
Soil Cd

Abstract This study compared electrokinetic (EK) remediation with and without interval power breaking in the removal of total and plant available cadmium (Cd) in the soil. Two laboratory experiments, i.e. EK remediation with interval power breaking (24-12 h power-on-off cycles) and conventional EK remediation (continuous power supply) with the same accumulated time (192 h) of power supply were conducted to remove soil Cd. After the EK remediation by interval power breaking, the total Cd removal efficiency in the soil rose to 38%, in comparison to 28% by the conventional EK remediation. As for the plant available Cd, the removal efficiency was enhanced from 52% to 63%. Additionally, the electric current during the EK remediation and electric conductivity after the EK remediation were higher in the soil treated by interval power breaking, which indicated an enhanced desorption and/or migration of charged species. It further meant that the higher removal efficiency of soil Cd by interval power breaking could be related to the enhanced desorption and/or migration of Cd species. This study indicated that both conventional EK remediation and EK remediation with interval power breaking were effective methods to remove soil Cd but EK remediation with interval power breaking was more efficient.

scholarly journals A Mono-2-Ethylhexyl Phthalate Hydrolase from a Gordonia sp. That Is Able To Dissimilate Di-2-Ethylhexyl Phthalate

2006 ◽  
Vol 72 (4) ◽  
pp. 2394-2399 ◽  
Author(s):  
Tuguhiro Nishioka ◽  
Makoto Iwata ◽  
Takuya Imaoka ◽  
Maiko Mutoh ◽  
Yoshihiro Egashira ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Contaminated Soil ◽  
Primary Structure ◽  
Independent Group ◽  
Serine Hydrolases ◽  
Cell Extracts ◽  
Significant Homology ◽  
Serine Esterases ◽  
Ethylhexyl Phthalate

ABSTRACT Gordonia sp. strain P8219, a strain able to decompose di-2-ethylhexyl phthalate, was isolated from machine oil-contaminated soil. Mono-2-ethylhexyl phthalate hydrolase was purified from cell extracts of this strain. This enzyme was a 32,164-Da homodimeric protein, and it effectively hydrolyzed monophthalate esters, such as monoethyl, monobutyl, monohexyl, and mono-2-ethylhexyl phthalate. The Km and V max values for mono-2-ethylhexyl phthalate were 26.9 ± 4.3 μM and 18.1 ± 0.9 μmol/min · mg protein, respectively. The deduced amino acid sequence of the enzyme exhibited less than 30% homology with those of meta-cleavage hydrolases which are serine hydrolases but exhibited no significant homology with the sequences of serine esterases. The pentapeptide motif GXSXG, which is conserved in serine hydrolases, was present in the sequence. The enzymatic properties and features of the primary structure suggested that this enzyme is a novel enzyme belonging to an independent group of serine hydrolases.

scholarly journals First Report of Beet necrotic yellow vein virus on Red Table Beet in Brazil

Plant Disease ◽  
2015 ◽  
Vol 99 (3) ◽  
pp. 423-423 ◽  
Author(s):  
J. A. M. Rezende ◽  
V. M. Camelo ◽  
D. Flôres ◽  
A. P. O. A. Mello ◽  
E. W. Kitajima ◽  
...  
Keyword(s):  
Amino Acid ◽  
Sugar Beet ◽  
Hairy Root ◽  
Contaminated Soil ◽  
The United States ◽  
Amino Acid Sequences ◽  
Yellow Vein ◽  
Polymyxa Betae ◽  
Rt Pcr ◽  
First Report

Beet necrotic yellow vein virus (BNYVV) is an economically important pathogen of sugar beet (Beta vulgaris var. saccharifera) in several European, and Asian countries and in the United States (3). The virus is transmitted by the soil-inhabiting plasmodiophorid Polymyxa betae and causes the rhizomania disease of sugar beet. In November 2012, plants of B. vulgaris subsp. vulgaris cv. Boro (red table beet) exhibiting mainly severe characteristic root symptom of rhizomania were found in a commercial field located in the municipality of São José do Rio Pardo, State of São Paulo, Brazil. No characteristic virus-inducing foliar symptom was observed on diseased plants. The incidence of diseased plants was around 70% in the two visited crops. As the hairy root symptom is indicative of infection by BNYVV, the present study aimed to detect and identify this virus associated with the diseased plants. Preliminary leaf dip analysis by transmission electron microscopy revealed the presence of very few benyvirus-like particles. Total RNA was extracted from roots of three symptomatic plants and one asymptomatic plant according to Toth et al. (3). One-step reverse-transcription–polymerase chain reaction (RT-PCR) was performed as described by Morris et al. (2) with primers that amplify part of the coat protein gene at RNA2. The initial assumption that the hairy root symptom was associated with BNYVV infection was confirmed by the amplification of a fragment of ~500 bp from all three symptomatic samples. No amplicon was obtained from the asymptomatic control plant. Amplicons were directly sequenced, and the consensus nucleotide and deduced amino acid sequences showed 100% identity. The nucleotide sequence for one amplicon (Accession No. KM433683) was compared with other sequences deposited in GenBank. The nucleotide (468 nt) and deduced amino acid (156 aa) sequences shared 93 to 100 and 97 to 99% identity, respectively with the corresponding nucleotide and amino acid sequences for other isolates of type A of BNYVV. The virus was transmitted to three of 10 red table beet plants inoculated with contaminated soil, and infection was confirmed by nested RT-PCR, as described by Morris et al. (1), and nucleotide sequencing. This is the first report on the occurrence of BNYVV in Brazil, which certainly will affect the yield of red table beet in the producing region. Therefore, mapping of the occurrence of BNYVV in red table beet-producing areas in Brazil for containment of the spread of the virus is urgent. In the meantime, precautions should be taken to control the movement of contaminated soil and beet roots, carrots, or any vegetable grown on infested land that might introduce the virus to still virus-free regions. References: (1) J. Morris et al. J. Virol. Methods 95:163, 2001. (2) D. D. Sutic et al. Handbook of Plant Virus Diseases. CRC Press, Boca Raton, Florida, 1999. (3) I. K. Toth et al. Methods for the Detection and Quantification of Erwinia carotovora subsp. atroseptica (Pectobacterium carotovorum subsb. atrosepticum) on Potatoes: A Laboratory Manual. Scottish Crop Research Institute, Dundee, Scotland, 2002.

scholarly journals Synergistic Effects of Adding a Substrate and an Organic Reductant for Stimulating the Bioremediation of 4-chloronitrobenzene-contaminated Soil

2020 ◽  
Author(s):  
Tian Li ◽  
Ping Zhang ◽  
Kun Qian ◽  
Tian.C Zhang
Keyword(s):  
Contaminated Soil ◽  
Organic Nitrogen ◽  
Synergistic Effects ◽  
Sufficient Information ◽  
Batch Reactors ◽  
Future Studies ◽  
Organic Nitrogen Source ◽  
Novel Strategy ◽  
First Time ◽  
Soil Batch

Abstract Background:Soil contaminated with 4-chloronitrobenzene (4NCB) is resistant to microbial degradation due to the electron-withdrawing properties of the nitro and chloro groups in 4NCB. Currently, sufficient information is not available on how to use biostimulation strategies to enhance the bioremediation of 4NCB-contaminated soil.Results:In the present study, a novel strategy was developed by utilizing the synergistic effects of adding an organic reductant (ascorbic acid, VC) and an organic nitrogen source (peptone) to stimulate the biodegradation of 4NCB-contaminated soil. Using this strategy, the bioremediation of 1 g-4NCB/ kg-1 soil could be completed within 8 days in soil batch reactors. Furthermore, the study discovered two 4NCB cometabolic intermediates in the soil reactors added with peptone and VC, and for the first time, 4NCB was transformed to 4-chlorofromanilide.Conclusion:The proposed strategy is promising because it is highly efficient, easy to control and involves a non-toxic, environmentally friendly substrate/reductant.). Finally, this approach warrants future studies to extend its applications to soils contaminated with other nitroaromatic compounds.

scholarly journals The Potential Effectiveness of Biochar Application to Reduce Soil Cd Bioavailability and Encourage Oak Seedling Growth

2020 ◽  
Vol 10 (10) ◽  
pp. 3410 ◽  
Author(s):  
Elnaz Amirahmadi ◽  
Seyed Mohammad Hojjati ◽  
Claudia Kammann ◽  
Mohammad Ghorbani ◽  
Pourya Biparva
Keyword(s):  
Contaminated Soil ◽  
Polluted Soil ◽  
Tolerance Index ◽  
Seedling Height ◽  
Loamy Soil ◽  
Potential Effectiveness ◽  
Soil Cadmium ◽  
Cd Removal ◽  
Soil Cd ◽  
Oak Seedlings

Today, it is very important to protect plants in soils contaminated with metals. We investigated the behavior of cadmium during the establishment of oak seedlings (Quercus castaneifolia C.A. Mey.) under biochar influence. This study was conducted in pots with loamy soil. Cadmium was added to soil at 0, 10, 30, and 50 mg per kg of soil, indicated by Control, Cd10, Cd30 and Cd50. Biochar was produced at 500–550 °C from rice husk and added at 1, 3, and 5% (wt/wt) levels, indicated by B1, B3, B5, and mixed with soil at planting in three replications. Generally, increasing biochar rates had significant effects on seedling height, diameter, and biomass. This coincided with Cd immobilization in the contaminated soil which reflects a decrease in Cd concentrations in the plant bioavailability of Cd. The tolerance index increased significantly, by 40.9%, 56%, and 60.6% in B1, B3, and B5 with Cd50, respectively, compared to polluted soil. The percent of Cd removal efficiency for Cd50 was 21%, 47%, and 67% in B1, B2, and B5, respectively. Our study highlights that biochar can reduce Cd bioavailability and improve the growth of oak seedlings in contaminated soil.

scholarly journals Complex Activity and Sensor Potential toward Metal Ions in Environmental Water Samples of N-Phthalimide Azo-Azomethine Dyes

Molecules ◽  
2021 ◽  
Vol 26 (19) ◽  
pp. 5885
Author(s):  
Stela Georgieva ◽  
Artem Bezfamilnyi ◽  
Anton Georgiev ◽  
Marian Varbanov
Keyword(s):  
Metal Ions ◽  
Copper Ions ◽  
Electrochemical Characterizations ◽  
Environmental Water ◽  
Complex Stability ◽  
Acid Base ◽  
Complex Activity ◽  
Complex Stability Constant ◽  
Real Samples ◽  
Base Analysis

Herein, the spectral and electrochemical characterizations of three different substituted N-phthalimide azo-azomethine (NAA) dyes (L) containing an o-hydroxy group and their NAA-M(II) chelates [M(II): Cu, Ni, Co, Pb] were reported by using UV–Vis and fluorescence spectroscopy and potentiometric and voltamperometric techniques. The pK value of the dyes as well as the stoichiometry and stability of the NAA-metal chelates were studied, and the stoichiometry was found to be mostly 1:2 (ML2) with high complex stability constant values. The sensor activity of N-phthalimide azo-azomethine derivatives toward pH and metal ions has been also investigated and tested for indicator application in acid–base analysis and detection of Cu(II) ions in real samples of surface river water using voltamperometric detection. The results showed that one of the ligands possesses the highest electrochemical response upon binding to copper ions and could be successfully used in the analysis of copper in water at a concentration range of the analyte from 3.7 × 10−7 to 5.0 × 10−6 mol L−1, with analytical characteristics of the method being Sr = 1.5%, LOD = 3.58 µg L−1 and LOQ =11.9 µg L−1

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