Electrokinetic soil remediation Research Papers (original) (raw)

2025, Revista Mexicana de Ciencias Agrícolas

La búsqueda de alternativas para el control de plagas agrícolas amigables al ambiente, que evite daños a la salud pública y al ecosistema aledaño, es una demanda actual que amerita atención bioética responsable. En este sentido, el objetivo del presente trabajo fue evaluar la actividad de los extractos de hojas de Dodonaea viscosa con polaridad ascendente sobre el desarrollo de Spodoptera frugiperda. Se obtuvieron extractos foliares de D. viscosa, por maceración en frío, usando disolventes en polaridad ascendente: hexano, diclorometano y metanol, los cuales se emplearon en las pruebas anti-alimentarias para conocer su efecto individual. Se realizó un experimento con dos bioensayos anti-alimentarios, uno con dieta artificial y otro de hojas de maíz; en ambos, se aplicaron los tres extractos obtenidos de D. viscosa a una concentración 1% m/v. El experimento se realizó con lavas L3 de la tercera generación S. frugiperda, a partir de las cuales se llevaron los bioensayos, durante todos ...

2025

Se realizo la modificacion superficial de nanotubos de carbon de pared multiple (NTCPM), empleando tres diferentes acidos organicos como sustratos, asistiendo la modificacion con energia ultrasonica, la cual ayudo a la dispersion de los NTCPM y a la modificacion superficial de los mismos. Se emplearon soluciones acuosas saturadas de los acidos organicos, a una temperatura de 50 °C, por 8 horas. Los NTCPM se caracterizaron mediante pruebas de dispersion empleando solventes polares y no polares, encontrando que en solventes polares se mantiene la dispersion por mas de 24 horas. En las espectroscopias de FT-IR (ATR), se encontraron las bandas correspondientes del acido carboxilico alrededor de 1725 cm -1 y por microscopia electronica de barrido, encontrando que los tres casos, se presenta una modificacion superficial, ademas de determinar el % de modificacion encontrando que el acido malonico presento un 3,83%.

2025, Revista Chapingo Serie Horticultura

El propósito de este trabajo fue evaluar el efecto antialimentario y la toxicidad de los extractos de Azadirachta indica, Piper auritum y Petiveria alliacea en larvas de Spodoptera exigua en condiciones de laboratorio y en un cultivo orgánico de tomate uva var. Santa a campo abierto. El trabajo se realizó con los extractos hexánico y metanólico de semillas de A. indica y hojas de P. auritum y de P. alliacea aplicados en diferentes concentraciones en larvas 4to estadío de S. exigua. Las variables que se evaluaron fueron Indice de disuasión alimentaria (FDI), Índice de supresión alimentaria (FSI), Porcentaje de mortalidad y CL 50 . El mayor efecto disuasivo alimentario se encontró en el extracto metanólico de Azadirachta indica, seguido por el de P. auritum, y el menor efecto en el extracto de P.alliacea. Los porcentajes de mortalidad para A.

2025

Este trabajo estudia las propiedades electrocatalíticas de la polianilina (PANI) y del poli-(3,4-etilendioxitiofeno) (PEDOT) hacia diferentes reacciones electroquímicas como la oxido-reducción de hidroquinona/benzoquinona (HQ/BQ), la reducción de oxígeno y la electrosíntesis de polímeros conductores. Nosotros sugerimos que la formación de complejos tipo ácido-base de Lewis ocurre entre las especies electroactivas y los polímeros conductores. Los polímeros conductores en estado oxidado, o mas específicamente el polarón, se comporta como ácido de Lewis y este puede formar complejos tipo donor-aceptor con especies alcalinas. Esta interacción tipo ácido-base de Lewis incrementa la velocidad de producción de radicales catiónicos. Por ejemplo, nosotros encontramos que la HQ se adsorbe débilmente sobre el PEDOT y que la reacción redox HQ/BQ se comporta como una reacción de transferencia de carga reversible controlada por difusión cuando se utiliza como electrodo platino recubierto con una ...

2024

El Berenjenol (21:24-epoxi-24-metil-cicloartano), obtenido del extracto de diclorometano de las hojas de Oxandra cf. xylopioides, es evaluado como biocida sobre el gusano cogollero del maíz, Spodoptera frugiperda. El berenjenol es usado en concentraciones de 25, 50, 100, 200 y 400 ppm y aplicado en una dieta artificial sobre larvas del segundo instar. Se determina el porcentaje de mortalidad a las 24, 48 y 72 horas y se calcula la DL 50 y DL 90 ; el análisis de mortalidad demuestra que el berenjenol tiene un efecto tóxico, siendo la dosis de 400 ppm la más mortal. El efecto del berenjenol es muy rápido y efectivo encontrándose valores de DL 50 de 319.6 ppm a las 24 horas y valores similares a las 48 y 72 horas.

2024, Conciencia Tecnológica

2024, International Journal of Mechanical and Civil Engineering

A lot of research work has shown that despite the effectiveness of the electrokinetic remediation technology in decontaminating heavy metal contaminated soils, more work is still required to fully understand the role of voltage in the remediation process. There is need to establish the optimum voltage that would best remove heavy metals from such contaminated soil and its attendant effect on the geotechnical properties of the remediated soil. Effect of voltage variation on the removal efficiency of lead, copper and the geotechnical properties of remediated heavy metal contaminated soil using electrokinetic remediation technique was investigated in this research. The contaminated soil was remediated by applying direct current (DC) to the remediation setup at 0.5V/cm, 1.0V/cm, 1.5V/cm and 2.0V/cm. The concentration of the heavy metals after remediation were determined using the Oxford Instrument Analyzer to evaluate removal efficiency, geotechnical properties tests were also conducted on the soil specimens at each phase of remediation. The results showed that the lead removal efficiency was highest at 2.0V/cm (86%) with the shortest remediation time of 5days and lowest at 0.5V/cm (39%) at 9days. 52% of copper was removed at 2.0V/cm in 5days and 29% at 0.5V/cm after 9days of remediation. At 1.0V/cm, the lead and copper removal efficiency are 75% and 40% respectively. There was no significant change in the Specific Gravity of all the soil samples with the test results lying between 2.0 and 2.2. The soil is generally silty fine sand with not less than 40% passing the sieve no.200 (75micron). 45% passed through sieve 75micron for unremediated soil and slightly reduced to 40%, 40.4% and 40.2% for 30V, 45V and 60V respectively. The soil is non-plastic with the liquid limit of between 25.8% and 29.5% belonging to the A-4 group of soil. The maximum dry density improved across all the three compactive efforts, from 1.8390g/cm 3 to 1.8480g/cm 3 with WAS compactive effort and from 1.8000g/cm 3 to 1.8320g/cm 3 with BSL method with an average optimum moisture content of 10%. The CBR values increases with increase in voltage applied. The unsoaked CBR values averagely increased with 31%, 18% and 7% for BSH, WAS and BSL compactive efforts respectively. The durability index with resistances of 89% and 90% to loss in strength was recorded at 1.0V/cm and 1.5V/cm respectively, this, when compared to the resistance to loss in strength of 71% in unremediated soil has respectively 25.3% and 26.8% durability advantages. There was also a consistent increase in the UCS values, from 381kN/m 2 to 474kN/m 2 and from 351kN/m 2 to 447kN/m 2 when WAS and BSL methods of compaction were used. Generally, there was improvement in the geotechnical properties of the remediated soil. These improvements are maximum at 1.0V/cm and 1.5V/cm with little or no further improvement at 2.0V/cm. It is recommended that 1.0V and 1.5V are suitable for remediation purpose since it requires low energy consumption.

2024

Samples of soil from SH-118 near Study Bute were procured with a nominal sulfate content of27 ,000 ppm. Geotechnical characterizatim of the soil samples indicated that the soil is highly plastic in nature and consists of 13% (on an average) of soluble components. The chemical characterizatim in batches indicated sulfate contents of two to three times the nominal value. Specimens of this soil compacted for a Liquidity Index of 50% were subjected to electro-osmosis treatment. The test results indicated a removal rate of7 mg/dayof sulfates after the rate of removal becomes constant. The rate of removal will further decrease to a lower level as more sulfates are removed from the specimen. If this rate can be maintained throughout the treatment process, the completion of the clean up would require several years. This length of time is clearly excessi\\l. Nevertheless, the major problem is posed by the large percentag::s of soluble components identified in the soiL The removal of aU the sulfates would result in the removal of all soluble components. This would result in unaUowable increases of the void ratio of the soiL The increase in void ratics would render any compacted hyer inapprq>riate as a bad-bearing layer. The main conclusion is that this sal can only be treated at the blJrow area, befoce placement in the pavement structure. Nevertheless, the power and water consumption coupled with the long time delay needed for the treatment process precludes the application of this methodology in the removal of sulfates from the soil in SH-118 near Study Bute. Another soil from the Fort Worth District with fewer sulfate contents was obtained. However, the evaluation ofthe soil indicated traces of sulfate. Thus, it was proposed to spike the soil with gypsum such that sulfate content of the soil would be from 1,000 ppm to 3,000 ppm. This amount of sulfate could be removed within a reasonable period. Four specimens were prepared with two water contents (95 and SO%) and two sulfate contents (1,000 and 3,000 ppm). The test results indicated that the sulfate removal was taster for 95% water content.

2024, Portugaliae Electrochimica Acta

2024, Journal of Applied Electrochemistry

This paper evaluates the remediation of soil spiked with lindane using a combined treatment consisting of electrokinetic soil flushing (EKSF) with air stripping to elucidate the main processes occurring in the soil when electric fields of 0.75 V cm−1 and 1.50 V cm−1 are applied. The results demonstrate that lindane is efficiently transported to the anodic and cathodic wells using flushing fluids containing sodium dodecyl sulfate (SDS). Additionally, an important amount is volatilized and stripped with the injected air. In the cathodic well, lindane is rapidly transformed into other species because of the strongly alkaline media. These other species are also found in the portions of soil next to this well, confirming the efficient transport of chlorinated organics with SDS. After 14 days of operation, nearly 50% of the spiked lindane can be removed from the soil. Operation with large electric fields does not improve the performance of the treatment technology and results in lower cur...

2024, Naturaleza y Tecnología

2024, DOAJ (DOAJ: Directory of Open Access Journals)

Metals pollution is often found in the immediate or neighboring areas of industrial or agricultural activities. This situation may significantly affect the environment, such as water, soil, and air pollution. Electrokinetic (EK) treatment is known to have higher efficiency for metals contaminated soil. However, the use of EK treatment is not widely as expected. This study employs EK treatment with different permeable reactive barriers and flushing solutions to remove Cd and Pb from agricultural soil. Soil pH, temperature, water content, electroosmotic flow, electric current, and metal concentration are calculated as responses to the EK treatment. Results showed that the EK treatments were effectively removed the metals from the contaminated soil. On the fifth day of the treatment, EK, which used activated carbon as PRB and citric acid as the chelating agent, removed a significant amount of Cd from the soil. Besides, the treatment using zeolite as PRB and citric agent as chelate can remove more than 90% of Pb after the sixth day of treatment. These results showed that PRB and chelating agents could effectively remove the metals from the contaminated soils.

2024, Boletín de sanidad vegetal. Plagas

2024, Tópicos de Investigación en Ciencias de la Tierra y Materiales

En los últimos años la síntesis verde de nanopartículas metálicas ha tenido un gran auge debido al uso de extractos vegetales, que han mostrado su viabilidad frente a los métodos físicos y químicos con el uso de extractos de plantas. Por lo tanto, surge la necesidad de identificar algunas especies que posean la capacidad de para la síntesis de nanopartículas metálicas. El extracto de la especie Cupressus govenianaque se caracterizó por FTIR, indicando la presencia de grupos funcionales carboxilo (-C= O), hidroxilo (-OH) y amino (-NH) atribuidos a las proteínas y compuestos con grupos terpenicos los cuales se les atribuye la capacidad como agentes reductores de los iones Ag+. La formación de las nanopartículas de plata fue caracterizada por espectroscopia de UV-Vis, observándose el plasmon característico de absorbancia entre los 418-430 nm. Esto reveló la reducción de Ag+ a plata metálica Ag0. Una muestra de la dispersión coloidal obtenida se caracterizó por SEM-EDS, donde se observa...

2024, Soil and Sediment Contamination: An International Journal

A comparative cost-effectiveness performance evaluation of graphite, glassy carbon, irrudium coated titanium and titanium anodes during electro-kinetic removal (EKR) of Pb(II) ions from contaminated clay soil was investigated. The influences of catholyte concentration (0.2-1N), spacing between electrodes (15-25 cm), treatment time (1-3 weeks) and distance from anode(5-15 cm) on Pb (II) residual concentration were evaluated and optimized using Response Surface Methodology. The relative contribution of the operating conditions follows the order; treatment time > distance from anode > electrode spacing > catholyte concentration. All the anodes yielded high Pb(II) removal with graphite exhibiting slower performance. The electro-osmotic volumes collected at the catholyte compartments suggest electro-osmosis as dominant removal mechanism while Ir-coated titanium exerted the highest electroosmotic mobility coefficients of 0.0054 cm 3 s-1 , 4.98 x 10-5 cm 2 V-1 s-1 and 0.00208 cm 2 A-1 s-1. The least energy expenditure of 46.21perkWh,46.21per kWh, 46.21perkWh,0.13 per kWhm-3 and 49.74perkWh.m−3mg−1wasattributedtographite,followedbytitaniumandthenIr−coatedtitanium.Themostexorbitantglassycarbonconsiderablyexhibitedtheleastperformancewith49.74 per kWh.m-3 mg-1 was attributed to graphite, followed by titanium and then Ir-coated titanium. The most exorbitant glassy carbon considerably exhibited the least performance with 49.74perkWh.m−3mg−1wasattributedtographite,followedbytitaniumandthenIr−coatedtitanium.Themostexorbitantglassycarbonconsiderablyexhibitedtheleastperformancewith2134.64 per kWh, 6.15perkWhm−3and6.15 per kWhm-3 and 6.15perkWhm−3and2094.8 per kWh.m-3 mg-1. This study underscores the relevance of taking anodic materials cost into considerations for better evaluation of EKR effectiveness for remediation of heavy metals contaminated-soils.

2023, IOP conference series

In France, sediments from river dredging are considered as waste. Without any special treatment, they must be stored in landfills. The dredged sediments of our area of study (North of France) are polluted with trace metals (antimony and zinc are above the French regulation threshold). The main objective of this study is to develop a new method of active depollution and dewatering treatment in order to enable the reuse of treated sediments. This treatment is carried out through ponds equipped with innovative geocomposite. This innovative geocomposite has two typical passive functions (filtration and drainage). In addition, it is functionalized by an innovative electrokinetic technology to confer it active roles (depollution and dewatering). Electrokinetic consists in applying a difference of electrical potential to a porous medium. We present here the results of a preliminary laboratory study that simulates this new method on a short-term (3 weeks) experiment. The results show that the electrokinetic treatment has an impact on the chemical and physical properties of sediments. The treatment reduces by 50% the concentration of zinc in the leachate after lixiviation.

2023, Tópicos de Investigación en Ciencias de la Tierra y Materiales

2023, ChemElectroChem

Many applications of electrokinetic remediation have focused on the removal of heavy metals. However, the application of electrokinetic technology in salt removal from contaminated soils and groundwater has not been extensively explored. Given the current global challenge and the impact of soil and groundwater salinity, it is tempting to suggest that the research community should apply this technology to generate in‐depth knowledge for determining the feasibility and efficiency of electrokinetic remediation in salt removal, particularly in addressing seawater intrusion in coastal aquifers, which is creating growing challenges in the freshwater supply, mainly in coastal and arid regions, in view of growing populations, economic and industrial growth, and climate change. This Review shows that there is a need to begin formulating a knowledge base about categories of materials, efficiencies, and limitations. Furthermore, the viability of this technology in the real field suggests a nee...

2023

This research study is a part of research of soft clay and expansive clay stabilization with electrokinetic process. The movement of electricity in the clay caused to several phenomena including electrochemistry, electrophoresis, and elektroosmosis. In this study, the author discusses the phenomenon of cation exchange on expansive clays that occur during the electrokinetic process. Exchanger ions in this study is a calcium ions (Ca 2+) which is used as a stabilizer. Research carried out on 3 types of soft clay and expansive to get the behavior of cation exchange phenomenon is more valid and complete on clay soil. Electrokinetic process is done by using direct current (DC) with capacity 5 until 10 Volt. Observation of the phenomenon of cation exchange is done by measuring the concentration of calcium ion (Ca 2+) and compared to other ion concentration contained in clay for a certain period by using the AAS method (Atomic Absorption Spectrum). The results showed that an increase in the concentration of Ca 2+ ions in the clay during the electrokinetic process. Increased Ca 2+ offset by a reduction in other cations, such as sodium (Na +), and pottasium (K +) in the clay. The results could be used as a basic knowledge in developing electrokinetic processes as an alternative to expansive clay stabilization effort.

2023, Environmental science and pollution research international

Electrokinetic process has emerged as an important tool for remediating heavy metal-contaminated soil. The process can concentrate heavy metals into smaller soil volume even in the absence of hydraulic flow. This makes it an attractive soil pre-treatment method before other remediation techniques are applied such that the chemical consumption in the latter stage can be reduced. The present study evaluates the feasibility of electrokinetic process in concentrating lead (Pb) and chromium (Cr) in a co-contaminated soil using different types of wetting agents, namely 0.01 M NaNO3, 0.1 M citric acid and 0.1 M EDTA. The data obtained showed that NaNO3 and citric acid resulted in poor Pb electromigration in this study. As for Cr migration, these agents were also found to give lower electromigration rate especially at low pH region as a result of Cr(VI) adsorption and possible reduction into Cr(III). In contrast, EDTA emerged as the best wetting agent in this study as it formed water-solubl...

2023

This research study is a part of research of soft clay and expansive clay stabilization with electrokinetic process. The movement of electricity in the clay caused to several phenomena including electrochemistry, electrophoresis, and elektroosmosis. In this study, the author discusses the phenomenon of cation exchange on expansive clays that occur during the electrokinetic process. Exchanger ions in this study is a calcium ions (Ca 2+ ) which is used as a stabilizer. Research carried out on 3 types of soft clay and expansive to get the behavior of cation exchange phenomenon is more valid and complete on clay soil. Electrokinetic process is done by using direct current (DC) with capacity 5 until 10 Volt. Observation of the phenomenon of cation exchange is done by measuring the concentration of calcium ion (Ca 2+ ) and compared to other ion concentration contained in clay for a certain period by using the AAS method (Atomic Absorption Spectrum). The results showed that an increase in ...

2023, Revista De Biologia Tropical

Lipid profile and assays of the antioxidant, insecticide and antifeedant activities of the marine sponge Iotrochota birotulata (Iotrochotidae: Demospongiae). It is estimated that three quarters of earth´s surface is occupied by the oceans. This constitutes the habitat of a large number of species of flora and fauna. As part of the marine organisms, the most studied biochemical phylum are Porifera, Cnidaria and more recently Ascomycota, from which a large number of chemical compounds have been isolated and identified. These have shown different types of biological activities, mainly cytotoxic, bactericidal and antioxidant. In this research the marine sponge Iotrochota birotulata collected in Punta Bello-Córdoba in the Colombian Caribbean was studied, and its lipid profile from the analysis of the corresponding mass spectra of its constituent compounds was determined, 19 fatty acids were identified, which are reported for the first time for this specie, besides 10 sterols were identified. Fatty acids with carbon chains between C15 and C27 were found, showing a wide structural diversity, which is characteristic of the porifera phylum. The sterols showed structures mainly with nucleus Δ 5 and Δ 7 , which are the most abundant in sponges. Moderate antioxidant activity was found in the stabilization of the radical cation ABTS+• and low activity in the stabilization of the radical DPPH•, the highest inhibition value was found in the aqueous extract with an IC 50 de 43.9 µg/ml against the radical cation ABTS+•, showing that I. birotulata can produce compounds with moderate antioxidant activity. In the insecticidal activity test, larval affectation was found in methanolic and aqueous extracts at all concentrations and at all times of exposure evaluated against Spodoptera frugiperda, it was also determined that these extracts induce an antifeedant effect on the larvae as part of the mechanism insecticide. The optimal conditions and exposure times were determined for the best efficiency of the assay, which were 3 000 µg/ml and 48 h for the methanolic extract and 2 000 µg/ml and 24 h for the aqueous extract, respectively. In conclusion, the evaluated extracts of the I. birotulata showed moderate antioxidant activity and good and interesting insecticidal and antifeedant activities.

2023, ACTA ZOOLÓGICA MEXICANA (N.S.)

El max Scyphophorus acupunctatus Gyllenhal 1838 (Coleoptera: Curculionidae) es una de las plagas más importante en agaves cultivados, produciendo daños severos a las hojas de las plantas y pérdidas de rendimiento hasta de 40% en el Estado de Yucatán. En estudios previos se demostró el efecto atrayente que ejercen las hojas de henequén sobre el insecto adulto de S. acupunctatus y el control efectivo que se logra de esta plaga usando hojas de henequén tratadas con insecticidas comunes. Por lo tanto, en el presente trabajo se llevó a cabo la identificación de los compuestos responsables de la actividad atrayente del henequén hacia el insecto S. Acupunctatus. Fragmentos de hojas de henequén se sometieron a una destilación por arrastre con vapor y el destilado se extrajo con diferentes solventes orgánicos. Se realizaron bioensayos de elección libre para determinar la actividad atrayente de cada uno de los extractos obtenidos, hacia el insecto S. acupunctatus, utilizando grupos de insecto...

2023, Procedia Chemistry

The combination used electro-assisted system and hydroponic phytoremediation which is hereinafter referred as hydroponic EAPR system for rapid removal of Pb 2+ and Cu 2+ from contaminated water which has been demonstrated in a laboratory-scale experiment. A hydroponic setting was used to evaluate the potential rapid removal and uptake of lead and copper concentration by water lettuce (Pistia stratiotes Linn.). The effectiveness of two-dimensional (2D) of cathode-pot electrode was introduced in this study. The results obtained from hydroponic EAPR system were compared with the plants exposed in the contaminated lead and copper water by using phytoremediation for 7 d process. The results showed that the accumulation of lead and copper were high in the plant roots. Analysis of chlorophyll content in treated plant with high lead concentration for EAPR system has showed that water lettuce could cope with lead and copper stress. The overall metal uptake in plant system was higher under EAPR system than one compared with phytoremediation process.

2023, Revista Colombiana de Entomología

The larvicidal activity of the neotropical “matico” Piper tuberculatum was evaluated. The secondary com- pounds were extracted of leaves, stems and mature spikes with fruits and seeds from wild plants and in vitro plants of Piper tuberculatum. The acute toxicities to the fall armyworm, Spodoptera frugiperda (Smith) (Lepidoptera: Noctui- dae), of extracts of spikes with fruits and seeds and in vitro plants of P. tuberculatum were evaluated by means of contact bioassays. Only CH2Cl2:MeOH (2:1) and EtOH extracts of mature spikes and CH2Cl2:MeOH (2:1) extract from in vitro plants showed significant levels of larval mortality. The CH2Cl2:MeOH (2:1) and EtOH extracts of mature spikes caused 90% mortality when doses of 0.1850 mg/µL were applied to the S. frugiperda in 24 and 48 h of exposure, respectively. The CH2Cl2:MeOH (2:1) extract from in vitro plants caused 95% mortality when doses of 0.1850 mg/µL were too ap- plied in 48 h of exposure. The mature spikes test best results were: LD50 ...

2023, Zenodo (CERN European Organization for Nuclear Research)

Las matrices ambientales de aire, suelo y agua se ven alteradas por contaminantes, por esta razón, es necesario encontrar tecnologías que sean capaces de proporcionar remediación ambiental. En la presente revisión se aborda a los contaminantes emergentes en aguas y el uso de nanopartículas para la remediación de suelos contaminados. Los contaminantes emergentes (CE) son aquellos que aún no se encuentran regulados, pero que pueden representar un peligro actual o futuro para el ecosistema en general. Los contaminantes orgánicos emergentes (COEs) son un grupo de sustancias orgánicas artificiales que no se encuentran en el medio ambiente de forma natural, y su presencia causa daños al ecosistema. Dentro de este grupo se definen tres subgrupos: los productos farmacéuticos y de cuidado personal (PPCPs), los contaminantes orgánicos persistentes (COPs) y las sustancias químicas disruptoras endócrinas (DEs). Se ha planteado el uso de nanomateriales de ingeniería (NMI) como posibles remediadores, dentro de ellos se encuentra las nanopartículas (NP). Estos son materiales cuyo tamaño es menor a los 100 nm y que constan de tres capas: superficial, caparazón y núcleo. Para su fabricación existen dos estrategias principales: de arriba hacia abajo y viceversa. Las NP más utilizadas son aquellas que tienen una base de hierro (ZVI). La remediación de suelos mediante el uso de NP se da a través de tres procesos principales: adsorción, transformación y fotocatálisis; además, se puede hacer uso de tres procesos adicionales como son la absorción, quimiosorción y fisisorción. En este trabajo se considera el uso de NP para la remediación de suelos contaminados con: metales pesados, pesticidas y compuestos orgánicos persistentes.

2023

In recent years, eletrokinetic (EK) remediation has become more popular as a novel method for removing chromium contamination from soil. This approach, however, is ineffective since it uses both cationic and anionic forms of chromium. In this work, a membrane-based technique was employed to increase the efficiency of eletrokinetic removal of chromium. Chromium removal from polluted sludge was studied in four bench-scale experiments, two of which have used a distilled water (EK-1, EK2&Membrane) and two of which have used acetic acid as a catholyte (EK-3, EK4&Membrane). The pH, total chromium, and fractionation of chromium in the sludge were measured after remediation. In the EK-1, EK-2&Membrane and EK-3, EK-4&Membrane trials, the average removal efficiency of total chromium was 47.6%, 58.6%, and 74.4%, 79.6%, respectively. In contrast to the eletrokinetic remediation strategy, which left around 80% of the sludge neutral or alkaline after treatment, the use of Membrane created acidic ...

2023, Rev. Fac. Nal. Agr. …

Evaluation of the insecticidal activity of the extracts from Piper grande Vahl (Piperaceae) using the biological model Drosophila melanogaster In this study, using the life cycle interruption test with the Drosophila melanogaster model, under (in-vitro conditions), the n-Hexane (roots and stems) and the EtOAc (roots and leaves) extracts were evaluated as insecticides and the results were promising. The larvae instar showed a singnificant activity reflected in the reduction of pupae population with respect to the control. The step from Pupae to Adult did no show inhibition because in all cases the average of the relation Pupae/Adult is found in values very near 1.The n-Hexane and the EtOAc extracts from roots were the most active with LC50 of 698.2 ppm and 1210.7 ppm. The n-Hexane (stems) and ETOAc (leaves) extracts showed a moderate activity with LC50 of 1654.1 ppm and 2376.0 ppm.

2023, Revista Colombiana De Entomologia

Se evaluó la actividad anti-alimentaria de extractos etanólicos y fracciones purificadas de residuos cítricos (Citrus sinensis y Citrus limonia) sobre una colonia establecida in vitro de Spodoptera frugiperda, especie considerada plaga en maíz y otros cultivos en Colombia. Se realizó una extracción etanólica de los residuos (cáscaras y semillas obtenidos a partir de desechos de la producción de jugos) y un posterior fraccionamiento líquido/líquido con n-hexano, diclorometano, acetato de etilo y agua. Los extractos y fracciones se caracterizaron por cromatografía de capa delgada y tamizaje fitoquímico con pruebas en base húmeda para identificar los principales núcleos bioactivos presentes. La actividad antialimentaria se evaluó mediante pruebas de preferencia con discos de Ricinus communis impregnados con una solución a diferentes concentraciones (0,25, 0,5, 0,75, 1% m/v) de los extractos y sus fracciones. Se determinaron los índices disuasivo, anti-apetitivo y la tasa de incremento de peso de las larvas. Los ensayos indicaron que la actividad anti-alimentaria fue dosis-dependiente, siendo los extractos y las fracciones en diclorometano de semillas las que mostraron mayor efecto antialimentario. Las fracciones de cáscara no mostraron actividad significativa a las concentraciones evaluadas. Los resultados sugieren que compuestos recuperados de residuos de cítricos, presentan potencial anti-alimentario y se podrían usar en el control de S. frugiperda.

2023, International Journal of GEOMATE

This research is a series study of electrokinetic process that used as an alternative of stabilization effort of expansive clays. In particular, an observation of the behavioral changes of soil properties and also behavioral changes of soil swell that occur due to the phenomenon of cation exchange during the electrokinatic process were conducted. The cation used in this study was calcium ions (Ca 2+) which are derived from the solution of lime which also used as a stabilizer. Electrokinetic test was conducted by using 2A and 25V DC power. The tested samples in this study were taken from three different locations in Central Java, namely: Purwodadi, Boyolali and Klaten. The composition and concentration of ions in expansive clays was tested by using AAS (Atomic Absorption Spectrum) method. Behavioral of soil properties known the limits of Atterberg (ASTM 4318 and ASTM 427) from testing while the swelling behavior of soil by testing of swelling (ASTM 4546). The observations against the behavior of clay expansive was at the condition of a change in the concentration of sodium ions (Na +) in the soil during the electrokinetic process. The results showed that at conditions of the concentration of sodium ions (Na +) was smaller than the initial concentration, the behavior of the value of the liquid limit (LL), the index plastic (PI) and the nature of the development of clay expansive indicated a downward trend, while the behavior of the boundary value shrinkage of the soil showed an upward trend. The results of this research can be used as a baseline data to the development of electrokinetic as an alternative effort of stabilization expansive clays.

2023

Almost all civil constructions were built on the ground. However, not all soil types can be used for construction due to the load supporting capacity of the soil and the soil deformation that occurs for each different soil type. One type of soil that has many problems on its supporting capacity is expansive clay soil. It is a type of soil that has a mineral content that easily absorbs water in wet conditions and also release water easily in dry conditions so that is soil can swell and shrink in a relatively short time. The purpose of this research is to know expansive soil characteristic in Bugel Village, Godong District, Purwodadi Regency, Central Java Province covering physical and mechanical properties. Based on laboratory tests, the soil in Bugel Village has Waverage = 60.90%. From result of atterberg limit test obtained result LL = 90,75%; PL = 24.138%; SL = 23.759%; And PI = 66.612%. According to Raman with a PI of 66.612% already shows the soil is expansive ground. For Gravit...

2023, Portugaliae Electrochimica Acta

In this work the physical-chemical properties of six different soils original from Tenerife Island, Spain, are related with the measured electrical current in an electrokinetic experiment. Results show that total electrical charge has relation with properties such as: total metal content, pH, carbon organic content, and cationic exchange capacity. Since all these properties are between those which allow to evaluate the fertility of a soil, an electrokinetic experiment with samples of this soil is proposed like diagnosis tool.

2023, Portugaliae Electrochimica Acta

2023, Revista Colombiana de Entomología

El gusano cogollero, Spodoptera frugiperda constituye la plaga más importante del maíz, Zea mays y para su control se utilizan principalmente insecticidas químicos sintéticos. El uso de compuestos botánicos es una alternativa potencialmente efectiva para el control de plagas. Se evaluó el efecto de formulados de Eucalyptus globulus, Jatropha curcas, Petiveria alliacea, Ricinus communis y Ruta graveolens, (A) a concentraciones de 5, 10 y 15 mL.L-1 de agua (B) sobre la mortalidad, inhibición alimentaria y peso de larvas de S. frugiperda. Mediante larvas de segundo y tercer estadio se realizaron bioensayos de aspersión y de elección para evaluar a través de un diseño factorial AxB + 3 testigos [insecticida químico (cipermetrina), botánico comercial (azadiractina) y testigo absoluto (agua)]. De los compuestos botánicos, la mortalidad resultó superior cuando se aplicó aceite de J. curcas (33,7%), e hidrolato de P. alliacea (26,2%) en concentración de 15 mL.L-1. Las Larvas alimentadas con...

2023, Revista Colombiana de Entomología

2023

En el presente trabajo se analizan algunos cambios producidos en las propiedades de un suelo sometido a impacto termico. Para llevar a cabo este estudio se utiliza una tecnica electrocinetica basada en los mismos principios que la electrorremediacion. El analisis se enfoca en la variacion, durante el tratamiento, de la corriente de electrolisis y de la diferencia de potencial generada en el interior del suelo en una region cercana a la camara de los electrodos. Los resultados obtenidos se explican con base en las caracteristicas iniciales que presentan los suelos estudiados antes del proceso electrocinetico.

2023

En la busqueda de hallar nuevas sustancias con la actividad insecticida de bajo impacto ambiental se estudiaron los efectos biologicos de un grupo de metabolitos secundarios, denominados withanolidos, extraidos de Salpichroa origanifolia, Jaborosa odonelliana y Nicandra physaloides (Solanaceae), asi como de compuestos analogos obtenidos por sintesis quimica a partir del withanolido mayoritario de S. origanifolia (Salpicrolido A), y de los extractos crudos de Physalis peruviana (Solanaceae) sobre las siguientes plagas agricolas: Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae); Ceratitis capitata (Wiedemann (Diptera: Tephritidae); Anticaesia gemmatalis (Hubner) (Lepidoptera: Noctuidae) y Diabrotica speciosa (Germar) (Coleoptera: Chrysomelidae). Los estudios se llevaron a cabo a traves de bioensayos que comprendieron la incorporacion de los productos en alimento (dieta artificial, discos foliares y bebederos de adultos, segun especie insectil) y por aplicacion topica de larvas...

2023, ChemistryOpen

Mercury represents one of the major toxic pollutants in water that affect human and ecosystem. Extensive efforts have been globally invested to remove mercury using various chemical and electrochemical approaches. In this study, I propose the use of bipolar electrochemistry for the first time for mercury depollution process. Mercury(II) is removed from aqueous solutions by direct electrodeposition on millimeter scale graphite rods held in a bipolar setup. By adjusting the strength of the applied electric field and the number of the graphite rods the efficiency of the system can be controlled. This wireless technique allows the use of multiple graphite rod arrays within the bulk cell which resulted in high removal efficiency (98 %) of Hg 2 + ions from the polluted solution. The method is straightforward, green, and efficient. The concept can be adapted to remove other heavy metal ions or electrochemically active contaminants from polluted water as long as their reduction potentials are within the water stability window.

2023, Rev. Soc. Entomol. …

RESUMEN. Continuando con la búsqueda de nuevos insecticidas naturales obtenidos de plantas, se estudió la actividad de un extracto de hojas senescentes (amarillas) de Melia azedarach L. (Meliaceae). Mediante pruebas de elección se estudió... more

2023, Revista Colombiana De Entomologia

2023

Background This work aims to describe the removal of a model anion (nitrate) from clay soils using electrokinetically assisted soil flushing coupled with permeable reactive barriers consisting of beds of anion exchange resin and to assess the influence of the electric field on the efficiency of this technology. Results Experiments have been carried out at the bench scale with spiked soil using electric fields ranging from 1.0 to 2.0 V•cm-1. Results show that removal of nitrates with this remediation technology is very efficient. About 90% of the nitrates contained in the soil can be removed in less than 1 week of operation with energy consumptions below 75 kWh•m-3 , being worth operating an electric field of 1.2 V•cm-1 because no improvements are found operating at higher voltage fields. 2 Conclusions There is a great effectiveness of the technology for the removal of nitrates, making it very promising for the removal of anionic pollutants from soils. The main path of change observed is the direction from anode to cathode. Dispersion in the axial direction is very small.

2023, Journal of Cultural Heritage

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2023, ChemistryOpen

2023, Southwestern Entomologist

Actividad Biológica de un Extracto de Semillas de Trichilia havanensis Jacq. 1 sobre Larvas de Spodoptera exigua (Hübner) 2 Biological Activity of a seed extract of Trichilia havanensis Jacq. 1 against Spodoptera exigua (Hübner) 2 Larvae

2023, Interciencia

The present study shows that natural products from Carica papaya can be considered as a valid alternative to control pests in agriculture. The insecticide properties of the seed extracts of four cultivars of C. papaya (Maradol, Mammee, Yellow and Hawaiian) were added to an artificial insect diet. Bioassays were conducted with hexanic, acetonic and methanolic extracts at concentrations of 10, 100 and 1000ppm. All tests were performed with the first larval stage of Spodoptera frugiperda. The response variable was insect mortality. Extracts from seeds of the Maradol, Mammee and Yellow cultivars of C. papaya, followed by extracts from seeds of the Hawaiian cultivar, applied at concentrations of 10, 100 and 1000ppm, were toxic on S. frugiperda larvae (50-70% corrected mortality rate). The acetonic extracts of the Maradol and Mammee cultivars at 10ppm were the most effective, causing mortalities of 73.6 and 62.8% of the larvae, respectively.