scholarly journals Hexachlorocyclohexane toxicity in water bodies of Pakistan: challenges and possible reclamation technologies

2021 ◽  
Author(s):  
Talat Ara ◽  
Waqar-Un Nisa ◽  
Muzammil Anjum ◽  
Luqman Riaz ◽  
Aansa Rukya Saleem ◽  
...  
Keyword(s):  
Low Cost ◽  
Industrial Effluents ◽  
Treatment Method ◽  
Agricultural Runoff ◽  
Crop Productivity ◽  
Indus Basin ◽  
Ex Situ ◽  
In Situ Remediation ◽  
Residual Concentration

Abstract Pakistan is an agro-economy country where the hexachlorocyclohexane (HCH) pesticides is being used to improve the crop productivity, as a result, the risk of contamination of soil and sediment has been increased. HCH exhibits all the characteristics of persistent organic pollutants (POP), therefore; added to the list of ‘new POPs’ in 2009. This review report revealed that the major rivers of Pakistan such as Indus Basin, River Ravi, River Chenab and their tributaries all are contaminated with HCH and the highest residual concentration (4,090 ng/g) was detected in pesticide burial ground in Hyderabad city. Major sources of HCH contamination were identified as agricultural runoff, discharge of untreated industrial effluents and surface runoff. In order to manage HCH pollution, various ex-situ and in-situ remediation techniques along with their merits and demerits are thoroughly reviewed. Among these, microbial bioremediation is low cost, environment friendly, effective in-situ remediation technique for remediation of HCH. Overall, the information provided in this manuscript will provide a future reference to the scientific community and bridge the knowledge gap between HCH release in environment and their mitigation through proper treatment method.

scholarly journals Heavy metal phytoremediation: Potential and advancement

2020 ◽  
pp. 81-93
Author(s):  
Pushpa Chaudhary Tomar ◽  
Shilpa Samir Chapadgaonkar ◽  
Varsha Panchal ◽  
Arpita Ghosh
Keyword(s):  
Heavy Metal ◽  
Industrial Waste ◽  
Research Work ◽  
Industrial Effluents ◽  
Ex Situ ◽  
Plant Tissues ◽  
Land Resource ◽  
Environmental Friendly ◽  
Different Types

Industrial activities lead to the release of different types of toxic metals into the environment. Phytoremediation has been established as one of the environmental-friendly and economical processes that have the potential for the remediation of industrial waste. Phytoremediation is used to extract metals from industrial effluents using ex-situ and in-situ treatments. Also, phytoremediation may be used to reclaim the polluted land resource for agricultural purposes. Moreover, this also prevents the bioaccumulation and biomagnification of xenobiotics from farming activities if carried out from polluted land. Phyto-mining can be done to recover and reuse the heavy metals from plant tissues after phytoremediation by plants. This study aimed to give a comprehensive review of recent research work in heavy metal phytoremediation.

In-Situ Oxidative Degradation of Emerging Contaminants in Soil and Groundwater Using a New Class of Stabilized MnO2 Nanoparticles

2016 ◽  
pp. 112-136
Author(s):  
Bing Han ◽  
Wen Liu ◽  
Dongye Zhao
Keyword(s):  
Organic Contaminants ◽  
Emerging Contaminants ◽  
Low Cost ◽  
Oxidative Degradation ◽  
In Situ Remediation ◽  
New Class ◽  
Mno2 Nanoparticles ◽  
In Situ Degradation ◽  
Trace Concentrations

Emerging Organic Contaminants (EOCs) such as steroidal estrogen hormones are of growing concern in recent years, as trace concentrations of these hormones can cause adverse effects on the environmental and human health. While these hormones have been widely detected in soil and groundwater, effective technology has been lacking for in-situ degradation of these contaminants. This chapter illustrates a new class of stabilized MnO2 nanoparticles and a new in-situ technology for oxidative degradation of EOCs in soil and groundwater. The stabilized nanoparticles were prepared using a low-cost, food-grade Carboxymethyl Cellulose (CMC) as a stabilizer. The nanoparticles were then characterized and tested for their effectiveness for degradation of both aqueous and soil-sorbed E2 (17ß-estradiol). Column tests confirmed the effectiveness of the nanoparticles for in-situ remediation of soil sorbed E2. The nanoparticle treatment decreased both water leachable and soil-sorbed E2, offering a useful alternative for in-situ remediation of EOCs in the subsurface.

Tip Treatment

2021 ◽  
pp. 343-358
Author(s):  
C. Julian Chen
Keyword(s):  
Tungsten Wire ◽  
High Field ◽  
Electrochemical Etching ◽  
Treatment Method ◽  
Ex Situ ◽  
Experimental Procedure ◽  
Treatment Methods ◽  
Spin Polarized ◽  
Afm Tips

This chapter discusses various methods for tip treatment. First, a general discussion about the experimental facts of STM and AFM tips is presented, which points to the subtleties and significance of the last few atoms at the tip apex. The standard method of making an STM tip is the electrochemical etching of a tungsten wire. The experimental procedure is described in detail. The study of the tip using field-ion microscopy is outlined. The tungsten tips freshly made from electrochemical etching often do not provide atomic resolution. Ex-situ and in-situ tip treatments are necessary. Several ex-situ tip treatment methods are described, inducing annealing, field evaporation, and annealing with a field. In-situ tip treatment method such as high-field treatment and controlled collision are described. Then, tip treatment for electrochemical STM is described. Tip treatment methods for spin-polarized STM are described. Finally, tip functionalization, especially with Xe atom and CO molecule, is described.

A Design of Continuous and Universal In Situ Remediation Appliance of Soil Combines

2013 ◽  
Vol 823 ◽  
pp. 205-213
Author(s):  
Yi Fang Li ◽  
Cheng Gong ◽  
Wen Qiang Wang ◽  
You Fang Li ◽  
Zi Feng Zhou
Keyword(s):  
Ex Situ ◽  
Time Interval ◽  
In Situ Remediation ◽  
Single Chip ◽  
Remediation Technology ◽  
Material Resources ◽  
Program Selection ◽  
Controlling System ◽  
Remediation Time

Continuous and universal in-situ remediation appliance of soil combines taking soil, transmission and restoration of soil, which can achieve the in-situ remediation continuously and avoid the drawback of massive labor power and material resources using domestic soil ex-situ remediation device. The appliance supports many kinds of soil remediation technology, realizing the function of universal technology. And as for the area with serious pollution, various technology combinations can be selected to extend its function. The motion of specific remediation device in the appliance utilizes the single-chip controlling technology, controlling the remediation time interval of different technology. The program selection with various remediation technologies can be finished with buttons. Single-chip controlling system responds quickly, runs stably and precisely controls the remediation device.

scholarly journals Structure-Dependent CO2 Gas Sensitivity of La2O2CO3 Thin Films

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Margus Kodu ◽  
Tea Avarmaa ◽  
Hugo Mändar ◽  
Rando Saar ◽  
Raivo Jaaniso
Keyword(s):  
Thin Films ◽  
Partial Pressure ◽  
Low Cost ◽  
Sol Gel ◽  
Working Environment ◽  
Ex Situ ◽  
Potential Candidate ◽  
Gas Sensitivity ◽  
Sensor Structure

Rare earth oxycarbonates are potential candidate materials for constructing simple and low-cost chemiresistive sensors for monitoring carbon dioxide (CO2) gas in the living and working environment for personal comfort and health reasons. Also, measurement of CO2 concentrations is needed in many industrial processes. Specifically, sol-gel made nanoparticles of Nd and La oxycarbonates have been studied previously as novel CO2 gas sensor materials. In this paper, pulsed laser deposition of La oxycarbonate (La2O2CO3) thin films was studied and structural properties of obtained thin films were characterized. Also, CO2 gas sensing ability of synthesized films was evaluated. The films deposited under CO2 partial pressure in various conditions were all Raman amorphous. In situ or ex situ annealing procedure at high CO2 partial pressure was needed for obtaining crystalline La2O2CO3 films, whereby hexagonal and monoclinic polymorphs were obtained in ex situ and in situ processes, respectively. Sensor structure, made using in situ process, was sensitive to CO2 gas and showed relatively fast response and recovery characteristics.

scholarly journals Isolation and Screening of Azo Dyes Tolerant Bacteria in Semi-Scale Industrial Effluents

2018 ◽  
Vol 4 (2) ◽  
pp. 59-61
Author(s):  
V K Pandey ◽  
N Kumar ◽  
A K Bhardwaj
Keyword(s):  
Methyl Orange ◽  
Organic Compound ◽  
Azo Dyes ◽  
Azo Dye ◽  
Trypan Blue ◽  
Industrial Effluent ◽  
Industrial Effluents ◽  
Ex Situ ◽  
Industrial Processing

Dyes are organic compound have colouring properties of the object which used in industrial application. Huge effluent are releasing by industrial processing, where the microorganism may naturally adopted against particular problems. Present work focused over the selection and screening few best native candidates from diverse bacteria from semi-skilled dye industrial effluent. From eleven isolated bacterial colonies only two are found resistant against azo dyes (Methyl orange and Trypan blue). During the screening it observed that isolates of bacteria (VN1 and VN2) were tolerates and decolorize azo dye up to 500 ppm. These bacterial strain can be used efficientlyremoval of dyes contamina-tion from ex-situ and in-situ.

Structural and Electrochemical Investigation of Na+ Insertion Into λ-Mn1-xNixO2

2015 ◽  
Vol 1810 ◽  
Author(s):  
J. R. Kim ◽  
G. G. Amatucci
Keyword(s):  
High Voltage ◽  
Low Cost ◽  
Electrochemical Techniques ◽  
Positive Electrode ◽  
Ex Situ ◽  
X Ray Diffraction ◽  
Positive Electrodes ◽  
Insertion Mechanism ◽  
First Time

AbstractIncreased demand for low cost energy storage options has expanded the scope of Na+ batteries considerably; and with the growing interest in Na-based chemistries, the importance of high voltage positive electrodes is quickly realized as the Na/Na+ redox introduces lower operating voltages as compared to Li/Li+ based electrochemical cells. The 4.7V LiMn1.5Ni0.5O4 spinel has exhibited considerable properties as a high voltage Li+ positive electrode, with a host structure (λ-Mn0.75Ni0.25O2) that may provide an analogous high voltage Na+ positive electrode. Structural and electrochemical properties of NaxMn1.56Ni0.44O4 and NaxMn2O4 are investigated for the first time[1] utilizing ex-situ, in-situ X-ray diffraction, and high-resolution electrochemical techniques to provide an insightful study of the Na+ insertion mechanism.

scholarly journals Study of ZnAl2O4 spinel nanoparticles synthesized using gelatin as organic precursor

Cerâmica ◽  
2019 ◽  
Vol 65 (374) ◽  
pp. 180-184
Author(s):  
H. P. Macedo ◽  
R. L. B. A. Medeiros ◽  
R. A. B. Nascimento ◽  
A. A. S. Oliveira ◽  
G. P. Figueredo ◽  
...  
Keyword(s):  
Spinel Structure ◽  
Pechini Method ◽  
Low Cost ◽  
Ex Situ ◽  
X Ray Diffraction ◽  
Organic Precursor ◽  
In Situ Xrd ◽  
Znal2o4 Spinel ◽  
Adsorption Desorption

Abstract In this work, zinc aluminate spinel powders were prepared by a fast, simple, eco-friendly and low-cost modified Pechini method using commercial gelatin as the organic precursor. The materials were calcinated at 600, 700 and 800 °C and characterized by thermogravimetric analysis, in situ and ex situ X-ray diffraction (XRD), N2-adsorption/desorption isotherms and scanning electron microscopy. The results showed that single phase ZnAl2O4 particles with spinel structure were successfully obtained resulting in a high purity, nanometric, homogeneous and mesoporous materials. The in situ XRD results showed that the crystalline spinel structure of ZnAl2O4 started forming at a temperature lower than 600 °C, revealing powders with crystallite size smaller than 40 nm, which increased with increasing the temperature (91% of increase between 600 and 800 °C). The effect of calcination time showed that the materials calcinated at 600 °C for 3 h presented the higher percentage of crystallite growth due to the increase of crystallinity. The ZnAl2O4 samples retained their pore size up to 700 °C.

scholarly journals Overview of Different Waste Treatment Methods

2018 ◽  
Vol 3 (03) ◽  
pp. 33-35
Author(s):  
Nida Tabassum Khan ◽  
Namra Jameel ◽  
Maham Jamil Khan
Keyword(s):  
Soil Water ◽  
Organic Compounds ◽  
Waste Treatment ◽  
Treatment Method ◽  
Aliphatic Hydrocarbons ◽  
Ex Situ ◽  
Treatment Methods ◽  
Chlorinated Aliphatic Hydrocarbons ◽  
Harmful Effects

Wastes including chlorinated aliphatic hydrocarbons, refractory organic compounds, aromatic derivatives, radionuclides etc., poses a serious threat to the environment. Therefore numerous in situ /ex situ treatment method are formulated to remove or immobilize such contaminates occurring in soil, water or air to minimize its harmful effects.

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