Ppm In Soil Research Articles

Elevated concentrations of soil carbon dioxide with partial root-zone drying enhance drought tolerance and agro-physiological characteristics by regulating the expression of genes related to aquaporin and stress response in cucumber plants

Water scarcity and soil carbon dioxide elevation in arid regions are considered the most serious factors affecting crop growth and productivity. This study aimed to investigate the impacts of elevated CO2 levels (eCO2 at rates of 700 and 1000 ppm) on agro-physiological attributes to induce drought tolerance in cucumbers by activating the expression of genes related to aquaporin and stress response, which improved the yield of cucumber under two levels of irrigation water conditions [75% and 100% crop evapotranspiration (ETc)]. Therefore, two field experiments were conducted in a greenhouse with controlled internal climate conditions, at the Mohamed Naguib sector of the national company for protected agriculture, during the winter seasons of 2021–2022 and 2022–2023. The treatments included eCO2 in soil under normal and partial root zoon drying (PRD, 100% ETc Full irrigations, and 75% ETc). All the applied treatments were organized as a randomized complete block design (RCBD) and each treatment was replicated six times. Untreated plants were designed as control treatment (CO2 concentration was 400 ppm). The results of this study showed that elevating CO2 at 700 and 1000 ppm in soil significantly increased plant growth parameters, photosynthesis measurements, and phytohormones [indole acetic acid (IAA) and gibberellic acid (GA3)], under partial root-zone drying (75% ETc) and full irrigation conditions (100% ETc). Under PRD condition, eCO2 at 700 ppm significantly improved plant height (13.68%), number of shoots (19.88%), Leaf greenness index (SPAD value, 16.60%), root length (24.88%), fresh weight (64.77%) and dry weight (61.25%) of cucumber plant, when compared to untreated plants. The pervious treatment also increased photosynthesis rate, stomatal conductance, and intercellular CO2 concentration by 50.65%, 15.30% and 12.18%; respectively, compared to the control treatment. Similar findings were observed in nutrient concentration, carbohydrate content, Proline, total antioxidants in the leaf, and nutrients. In contrast, eCO2 at 700 ppm in the soil reduced the values of transpiration rate (6.33%) and Abscisic acid (ABA, 34.03%) content in cucumber leaves compared to untreated plants under both water levels. Furthermore, the results revealed that the gene transcript levels of the aquaporin-related genes (CsPIP1-2 and CsTIP4) significantly increased compared with a well-watered condition. The transcript levels of CsPIP improved the contribution rate of cell water transportation (intermediated by aquaporin’s genes) and root or leaf hydraulic conductivity. The quantitative real-time PCR expression results revealed the upregulation of CsAGO1 stress-response genes in plants exposed to 700 ppm CO2. In conclusion, elevating CO2 at 700 ppm in the soil might be a promising technique to enhance the growth and productivity of cucumber plants in addition to alleviating the adverse effects of drought stresses.

Enhanced enrichment of rare earth elements during pedogenesis under subtropical climate

Rare earth elements (REE) are crucial strategic resources, and weathering-crust rare earth deposits are one of the primary sources. To systematically understand the geochemical behavior (e.g., enrichment and leaching) of REE in soils (or weathering crusts) formed from diverse parent rocks under varying climatic conditions, 171 soil profiles (weathering crusts) developed from three main types of parent rocks (granite, basalt, and carbonate rock) worldwide were studied. Granite shows the highest concentration of rare earth elements at 264 (interquartile range (IQR): 278) ppm, 171 (IQR: 151) ppm and 11.9 (IQR: 36.4) ppm in basalt and carbonate rock, respectively (median test: p < 0.05). The median REE values within the soil profiles were significantly different (median test: p < 0.05), with the concentration of 318 (IQR: 441) ppm, 267 (IQR: 217) ppm and 207 (IQR: 417) ppm in soils derived from granite, carbonate rock, and basalt, respectively. Principal component analysis (PCA) and Linear mixed-effects models (LME) revealed that soils developed from granite and basalt inherit the mineral characteristics of their parent rocks, with REE concentrations primarily influenced by the REE content of the parent rock and climate. In contrast, the REE concentrations in soils developed from carbonate rocks are predominantly controlled by climate. LME and correlation analysis indicates that the enrichment of REE (Q REE ) shows a trend of initially increasing and then decreasing with rising temperature and precipitation, due to variations host clay minerals. The greatest enrichment occurs in the subtropical region (mean annual temperature (MAT) = 15 ̶ 23 °C; mean annual precipitation (MAP) = 1000 ̶ 2000 mm); weathering-crust type REE deposits are primarily found in the subtropics.

From Farm to Fork: Enhancing Agricultural and Food Safety Monitoring with Laser-Engineered Graphene Sensors

In the critical fields of precision agriculture and food safety, the demand for accurate and sensitive monitoring tools for fertilizers, pesticides, and food-borne pathogens cannot be overstated. Our collaborative research with commercial entities seeks to overcome the challenges faced by current electrochemical ion-selective, enzymatic, and immunosensors, which often fall short in selectivity, stability, and sensitivity, particularly under field conditions. We showcase the tunable properties of Laser-Induced Graphene (LIG) – such as surface wettability, roughness/area, and electrical conductivity – and their instrumental role in enhancing the commercial viability of these sensor technologies.We demonstrate the conversion of hydrophilic Laser-Induced Graphene (LIG) to a near-superhydrophobic state using an innovative dual-laser process in ambient conditions. This method intricately sculpts the surface into micro and nanoscale structures reminiscent of a lotus leaf, resulting in nearly superhydrophobic characteristics. By modifying the laser's power, speed, and fluence, we can also fine-tune the electroactive surface area and electrical conductivity, significantly impacting sensor functionality. For solid contact ion-selective electrodes (SC-ISEs), enhancing the LIG surface with high hydrophobicity prevents water layer accumulation at the ion-selective membrane and electrode interface. This design expels water from within the membrane, fosters stronger membrane-electrode adhesion, and consequently, diminishes signal interference. Such improvements are instrumental in boosting the sensor's accuracy and extending its operational lifespan. In contrast, a hydrophilic LIG with a large surface area enhances catalytic efficiency and allows more biorecognition agents to adhere to its surface, thereby amplifying the sensitivity of enzymatic pesticide sensors. Lastly, a flat, hydrophilic LIG surface ensures an even distribution of antibodies, which enhances the performance of sensors detecting foodborne pathogens.These modifications to LIG and the resulting sensors have substantial commercial potential. We have developed ions sensors for nitrate, ammonium, potassium, calcium, and magnesium have demonstrated near-Nernstian sensitivities, extensive sensing ranges across four orders of magnitude, and the ability to detect concentrations as low as 1 ppm in soil and water samples. These sensors are currently being integrated into commercial soil moisture and temperature probes for monitoring in farm fields. The pesticide sensing capability of the sensor can reach an extremely low picomolar detect limit for organophosphates, the nanomolar regime for neonicotinoids, and micromolar regime for glyphosate in surface waters. These sensors are currently being interfaced with LIG-based mist/fog harvesting devices to monitor pesticide and spray drift in farm fields. Finally, the LIG-based Salmonella sensors are capable of monitoring bacteria such as Salmonella to about 10 CFU/mL in actual food matrices such as chicken broth without the need for sample preconcentration or costly lab analyses.This research forges innovative avenues in agriculture and food safety monitoring, laying the groundwork for mass production of efficient and economical sensors. We believe this technology will revolutionize field monitoring, significantly advancing sustainable agriculture and improving public health safety. Figure 1

Lithium Isotope Geochemistry in the Barton Peninsula, King George Island, Antarctica

Lithium (Li) has two stable isotopes, 6Li and 7Li, whose large relative mass difference is responsible for significant isotopic fractionation during physico-chemical processes, allowing Li isotopes to be a good tracer of continental chemical weathering. Although physical erosion is dominant in the Polar regions due to glaciers, increasing global surface temperature may enhance chemical weathering, with possible consequences on carbon biogeochemical cycle and nutriment flux to the ocean. Here, we examined elemental and Li isotope geochemistry of meltwaters, suspended sediments, soils, and bedrocks in the Barton Peninsula, King George Island, Antarctica. Li concentrations range from 8.7 nM to 23.3 μM in waters, from 0.01 to 1.43 ppm in suspended sediments, from 9.56 to 36.9 ppm in soils, and from 0.42 to 28.3 ppm in bedrocks. δ7Li values are also variable, ranging from +16.4 to +41.1‰ in waters, from −0.4 to +13.4‰ in suspended sediments, from −2.5 to +6.9‰ in soils, and from −1.8 to +11.7‰ in bedrocks. Elemental and Li isotope geochemistry reveals that secondary phase formation during chemical weathering mainly control dissolved δ7Li values, rather than a mixing with sea salt inputs from atmosphere or ice melting. Likewise, δ7Li values of suspended sediments and soils lower than those of bedrocks indicate modern chemical weathering with mineral neoformation. This study suggests that increasing global surface temperature enhances modern chemical weathering in Antarctica, continuing to lower δ7Li values in meltwater with intense water-rock interactions.

Identifying multi-metal prospect using regional soil and stream sediment geochemical data in Bidou, Nyong Series, North West of Congo Craton

The Congo Craton is a well-known mineralized Province in Africa being host to a wide variety of mineral deposits. Exploration work in the Nyong Series over the years has yielded only gold and iron prospects. Analysis of 460 regional soils and 60 stream sediment samples revealed new mineral prospects in the area. Au content ranges from below detection limit (bdl) to 216 ppb and bdl to 18.1 ppm in soil and stream sediments, respectively. Ag contents are within the range of 5 ppb to 237 ppb in soils and from 0.01 to 1.02 ppm in stream sediments. An uncommon positive correlation is noticed between Au and U in the soils while Au–Ag correlation is observed in stream sediments. La attains a maximum concentration of 123,500 ppb in soil and >1.5% in stream sediments implying a possible mineralization of La in this study area. Principal component analysis (PCA) presents loadings of high field strength elements and chalcophile elements in factors 1 and 2 of both soil and stream sediments illustrating input from the catchment geology. Factor maps turn out a single anomaly for Au–U in soil. Streams draining the Bidou prospect yield wider Au anomalies within the prospect. Surficial geochemical maps display Bidou hill as a single urge prospect with possible disseminated mineralization throughout the entire hill. Other potential minerals of interest within Bidou prospect include Ag, Cu, Th, U, and REEs.

Detection of benzo[a]pyrene with silver nanorod substrate in river water and soil based on surface-enhanced raman scattering

Benzo[a]pyrene (BaP) widely presents in soot, tar, cigarette smoke, and has a strong carcinogenic effect. It is stable in the environment and accumulates through the biological chain. Therefore, it is of vital importance to develop a simple and rapid method to detect Bap in real environment. In this work, based on surface enhanced Raman scattering (SERS) technology, a silver nanorod (AgNR) substrate was developed for detecting BaP in river water and soil. Vibration modes of BaP’s characteristic peaks were calculated by density functional theory (DFT). The characteristic peak of BaP is at 1234 cm−1. In the range of 10 ~ 100 ppb, the characteristic peak intensity of BaP shows good linear relationship with the concentration. The limit of detection (LOD) is down to 1 ppm in river water and 10 ppm in soil, respectively. These results demonstrate the applicability of the AgNR substrate for SERS detection of BaP which present an application prospect of AgNR substrate in environmental detection.

Critical limit of boron in acid laterite soil for cultivation of sunflower (Helianthus annus L.)

The present investigation was carried out to study the critical limit of boron and its response to Sunflower (Helianthus annus L.) in acid laterite soils of Odisha. This work will be of immense importance of recommending appropriate doses for soil boron application. The critical limit of boron in soil and plant is the level below which there is appreciable response to boron application. The concept of critical limit distinguishes deficiency from sufficiency, which could be employed to advice on need for nutrient fertilization. It has been realized as the second most important micronutrient constraint in crops after that of zinc (Zn) on global scale. Deficiency of B mainly occurs in acidic and lateritic soils. Its application only slightly above the optimum level proves to be toxic to plants. Therefore the study was taken up emphasizing the need for a careful appraisal of available B status in soils for judicious use of boron fertilizers and establishing the critical concentration of boron in Sunflower. The experiment was laid out in factorial completely randomised block design in laterite Soil during Zadi, in 2018 at AICRP on Micronutrients, department Soil science and Agricultural chemistry, OUAT, Bhubaneswar, with two factors (5 Soil types and 5 boron doses of 0kg boron/ha, 0.5kg boron/ha, 1.0kg boron/ha, 1.5kg boron/ha and 2kg boron/ha.) with 25 treatments replicated twice. The plant height, seed dry weight and number of seeds per head showed positive and significant correlation with the soil boron application in all soil type except in soil type 2 and soil type 3 where the growth declined after kg/ha and kg/ha respectively. The critical limit of boron was found to be 0.58ppm in soil and 23.4 ppm in plants.

USING γ RAY-INDUCED SILVER NANOPARTICLES ON CONTROL OF CLUBROOT DISEASE OF CHINESE CABBAGE CAUSED BY PLASMODIOPHORA BRASSICAE

Plasmodiophora brassicae- the casual cause of clubroot disease of plants belonging to the family Brassicaceae. This soil-borne fungus infects plants through root hairs. Diseased roots become swollen and deformed. Thus, it’s difficult for plants to absorb water and nutrients. There are some methods used to control this disease including soil fumigation, soil pH control, fungicides, surfactants applications, calcium supplementation, but the results are still restricted. Plasmodiophora brassicae was isolated, identified and artificial inoculated on the Chinese cabbage. The rate of root hair infection and gall formation depended on the spore density and growth media. The increase of the pathogen density lead to the increase of disease symptoms. Silver nanoparticles (SNPs) are widely used as an agent for antifungal treatment. The antimicrobial activity of the nanoparticles varies on the size, shape, and the function of the surface area. The γ - irradiation method to synthesize SNPs is known as a method that can be controlled the out coming sizes, shapes and size distribution of particles. The average diameter of silver nanoparticles in this research was 9.5nm. In the liquid culture and soil, SNPs exhibited a controlling effect on P. brassicae. The fungicide activity depended on the SNP concentrations and the medium; no disease symptoms were found at the SNP concentrations of 1.06 ppm in the liquid culture, and 10 and 20 ppm in soil. Results of the study also showed that the biomass and height of infected plants were much lower than those of the healthy plants. Comparing to the plants that were grown in the sterilized soil, there was not significant difference between the biomass and the height of plants exposed to pathogen and treated with SNPs.

Winter road management effects on roadside soil and vegetation along a mountain pass in the Adirondack Park, New York, USA

In 2003–2005, we resurveyed and expanded plots surveyed in 1985 to examine the cumulative impact of road salt (sodium chloride) and sand along a two-lane highway in the Adirondack State Park in New York State (USA). Annual salt applications in the period 1985–2005 ranged from 50 tonnes per centerline-km (1985) to 140 tonnes (2005) and sand applications ranged from nearly zero tonnes (2005) to 325 tonnes (1985). Roadside soils and vegetation were significantly impacted by salt deposition compared to soils and vegetation 30 m and 150 m from the road. Roadside soil contained more sand, less organic matter, had a lower cation exchange capacity, was denser, and retained less water than soils 30 m and 150 m from the road. The concentration of sodium in roadside soils was elevated (103 vs. 44 ppm in soil 150 m from the roadside), and roadside concentrations of plant-nutritive cations were lower than 150 m from the road (roadside Mg, Ca and K concentrations were 0.2, 5, and 1 ppm respectively vs. 23,168, and 30 ppm at 150 m from the road). Along the roadside, paper birch trees (Betula papyrifera) and other woody vegetation present in 1980 were absent in 2004, suggesting that survival and recruitment of paper birch trees was impacted by degradation of soil fertility, deposition of road salt and aerosolization of salt from the roadway. Roadside environmental degradation caused by winter road management has worsened since 1980; revegetation with native salt-tolerant plants may provide some mitigation of the most severe effects. Overall, we conclude that the full extent of roadside environmental degradation caused by winter road management can take decades to manifest, and this may be the case more generally along cold-climate montane roadways.

Relationship of Respiratory Diseases and the Lead Level in Tiran & Karvan Region, Iran

Abstract Aims: Lead is emerged as one of the most hazardous elements, existing in the air and soil, which can create irreparable outcomes in the human body due to its highly severe damages. the aim of this study was to determine the relationship between Lead level and the respiratory diseases in Tiran & Karvan Region, Iran. Instrument & Methods: The research methodology was analytical based on the documents and evidence, and library studies and was performed during 2011 to 2015 in Tiran & Karvan Region, Isfahan Province, Iran. The respiratory diseases statistics regarding the studied area was gathered from the information and statistics of Isfahan University of Medical Sciences and Iran Management Center for Diseases during 2007 to 2009 documents (3215 cases). 110 soil samples and 55 water samples were collected from different positions at Summer 2011, randomly. The variation map of the respiratory diseases and lead spatial distribution for research area were drawn by Arc GIS 10.2 software. Findings: The concentration of lead was 59.4±7.9ppm in soil and 48.2±4.1ppm in water of the region. The lead variation map showed that the soil in the eastern, northern and western areas consists of a relatively high portion of lead. Also special distribution of the respiratory diseases in Tiran & Karvan showed that the disease variation is in a cluster manner and that the disease follows a special centralization. Conclusion: There is a direct relation between respiratory diseases distribution and the existence of lead in Tiran & Karvan Region, Isfahan Province, Iran.

Toxicity and Nonrepellency of Spinosad and Spinetoram on Formosan Subterranean Termites (Isoptera: Rhinotermitidae).

Spinosyn products, spinosad and spinetoram, are widely used to control various agricultural pests. Spinosad has been tested on Kalotermitidae and Termitidae but not on Rhinotermitidae, the most destructive of termite families. In this study, we tested the effect of spinosad and spinetoram on Coptotermes formosanus Shiraki. Both no-choice and choice tests were conducted using three concentrations, 1 ppm, 25 ppm, and 50 ppm, of the spinosyn products Entrust, Tracer, and Radiant on three substrates, sand, soil, and filter paper. In the no-choice test in sand, >85% mortality was observed at 25 and 50 ppm after 1 d of exposure followed by 100% mortality at 7 d. Similarly, after 7 d at 25 and 50 ppm in soil and filter paper, 100% mortality was observed, but compared to sand at 1 d, mortality was low. In the two-choice test, observations before the onset of termite mortality showed that none of the products or concentrations was repellent. Likewise, in the multiple-choice test, there was no repellency or preference of termites among 1 ppm, 25 ppm, 50 ppm, control, and release chamber at all three concentrations, and the tunnel area in the control and treated choices were not significantly different. These findings support the nonrepellent attribute of spinosyns on C. formosanus .

EFFECT OF DIFFERENT SOURCES AND LEVELS OF POTASSIUM ON GROWTH, YIELD AND CHEMICAL COMPOSITION OF FABA BEAN PLANTS

A pot experiment was undertaken out door at the farm of Faculty of Agric. El-Mansoura Univ. during the winter season of 2014 to investigate the effect of different sources of potassium fertilization on vegetative growth, chemical composition and yield of faba bean plants (Vicia faba L.). Ten treatments were arranged in a complete randomize block design with 3 replicates, thus, the total number of the experiment was 30 pots as follows: (Control treatment: without K-fertilization), (50 kg K2O.fed-1 as potassium sulphate (RD), 37.5 kg K2O.fed-1 as potassium sulphate, and 62.5 kg K2O.fed-1 as potassium sulphate) and (50 kg K2O.fed-1 as potassium thio sulphate (RD) (137 lit.fed-1), 30 kg K2O.fed-1 as potassium thio sulphate (82 lit.fed-1 ), and 70 kg K2O.fed-1 as potassium thio sulphate (191.8 lit.fed-1 ) as well as (200 kg.fed-1.feldspare, 100 kg.fed-1 feldspare and 300 kg.fed-1 feldspare ). Results reveale that the mean values of vegetative growth parameters as (plant height, fresh and dry weight as well as leaf area), fresh weight of pods and seeds, N, P, K, Fe in plant foliage and seeds were increased significantly with increasing rates of potassium fertilizers. The highest values were recorded with using 62.5 kg K2O.fed-1 as potassium sulphate. As for the; EC and pH of soil was decreased with increasing rates of potassium sources. The available nutrients in soil (N, P, K and Fe) increased significantly with increasing rates of potassium fertilizers. The highest available values of N, P, K and Fe ppm in soil were recorded with using 62.5 kg K2O.fed-1 as potassium sulphate.

Multimedia exposures to arsenic and lead for children near an inactive mine tailings and smelter site

Children living near contaminated mining waste areas may have high exposures to metals from the environment. This study investigates whether exposure to arsenic and lead is higher in children in a community near a legacy mine and smelter site in Arizona compared to children in other parts of the United States and the relationship of that exposure to the site. Arsenic and lead were measured in residential soil, house dust, tap water, urine, and toenail samples from 70 children in 34 households up to 7 miles from the site. Soil and house dust were sieved, digested, and analyzed via ICP-MS. Tap water and urine were analyzed without digestion, while toenails were washed, digested and analyzed. Blood lead was analyzed by an independent, certified laboratory. Spearman correlation coefficients were calculated between each environmental media and urine and toenails for arsenic and lead. Geometric mean arsenic (standard deviation) concentrations for each matrix were: 22.1 (2.59) ppm and 12.4 (2.27)ppm for soil and house dust (<63μm), 5.71 (6.55)ppb for tap water, 14.0 (2.01)μg/L for specific gravity-corrected total urinary arsenic, 0.543 (3.22)ppm for toenails. Soil and vacuumed dust lead concentrations were 16.9 (2.03)ppm and 21.6 (1.90) ppm. The majority of blood lead levels were below the limit of quantification. Arsenic and lead concentrations in soil and house dust decreased with distance from the site. Concentrations in soil, house dust, tap water, along with floor dust loading were significantly associated with toenail and urinary arsenic but not lead. Mixed models showed that soil and tap water best predicted urinary arsenic. In our study, despite being present in mine tailings at similar levels, internal lead exposure was not high, but arsenic exposure was of concern, particularly from soil and tap water. Naturally occurring sources may be an additional important contributor to exposures in certain legacy mining areas.

Comparative Study of Heavy Lead Pollution in Roadside Soil and Plants by Railway and Highway at Tangail District in Bangladesh

This study explains the effect of heavy Lead pollution in soil and plants along the highway and railway of Tangail district. The metal concentration in soil and plant is decreased with increasing distance from the road of highway and railway. Lead is one of the most toxic elements. It is non-biodegradable and its toxicity does not change with time. Use of leaded gasoline in vehicles and train are known as the major source of lead pollution. Highway and railway of Tangail are two busiest routes of Bangladesh and pollution is rising day by day. To reveal the present situation in soil and plant samples were collected at various distances (0m, 15m, 30m) from Railway and highway roads and analyzed for lead by Atomic Absorption Spectrophotometric (AAS) method. The results show that the soil and plant samples along these places are contaminated with lead. The highest lead contents 0.1931 ppm in soil and 0.1358 ppm in plant was found for highway on road at 0m distance. Conversely, the highest lead contents 0.0967 ppm in soil and 0.0652 ppm in plant was found for railway on road at 0m distance. Among two types of major transportation system railway pollution is smaller than highway and hence railway transportation system is environment friendly.

Cu- and Zn-Soil Anomalies in the NE Border of the South Portuguese Zone (Iberian Variscides, Portugal) Identified by Multifractal and Geostatistical Analyses

Extensive Cu- and Zn-soil geochemical data in the Albernoa/Entradas–S. Domingos region (NE border of the Iberian Pyrite Belt, South Portuguese Zone) were examined to separate anomalies from background using the concentration–area fractal model. Distribution patterns of Cu and Zn concentrations in soil are primarily influenced by bedrock. The regional threshold values of Cu- and Zn-soil contents over metasedimentary sequences are 20–25 and 20–60 ppm, respectively, becoming 30–50 and 20–90 ppm, respectively, when metavolcanic rocks are present. The first-order threshold values for Cu are 80–90 ppm in soils over metasediments and 70–80 ppm in soils over sequences bearing metavolcanics. For Zn, the first-order threshold values are 40–80 and 90–100 ppm in soils over metasediments and metavolcanic rocks, respectively. Metasediments and metavolcanics comprising significant sulphide disseminations are outlined by Cu- and Zn-soil values above 100 and 300 ppm in soil, respectively. On the basis of these results, Alvares and Albernoa/Entradas areas emerge as the first priority targets for exploration. The observed non-coincidence of Cu- and Zn-soil anomalies in soil in the area could reflect difference in element dispersion during weathering, they mostly indicate distinct metal sources related to the original composition of different rock types or to chemical changes developed during Variscan deformation/re-crystallization path. The established regional baseline data can be used as reference for environmental studies.

Micro organisms living in zinc contaminated soil - a review

Zinc (Zn) has important effect on soil microbes; resultant of its ability to enhance as well as reduce activity depends on its concentration. Heavy metal contamination in soil is affecting animals, human and crop as well. As a result of industrialization for example smelting of metals, mining, electroplating, energy and fuel production, fertilizer, gas exhaust, municipal waste generation sewage and pesticide application, municipal waste generation, etc. Metal pollution is among one of the drastic ecological threats today. In several researches the effects of various solution of Zn on soil microbial communities and activities were analyzed by different concentration of Zn into a surface soil. Research lead to finding that, soil microorganisms is highly sensitive to metal concentration. Metal exerted poisoning impact after high amount was added. Higher concentration resulted slower growth of microbes. Levels of zinc in excess of 500 ppm in soil compete with other essential metals, such as iron and manganese for plant uptake. We can conclude that soil microbial communities and activities can adapt to Zn pollution to a certain extent. The micro organisms can play a substantial job in the remediation of heavy metals and other pollutants.

DNA-polyfluorophore Chemosensors for Environmental Remediation: Vapor-phase Identification of Petroleum Products in Contaminated Soil.

Contamination of soil and groundwater by petroleum-based products is an extremely widespread and important environmental problem. Here we have tested a simple optical approach for detecting and identifying such industrial contaminants in soil samples, using a set of fluorescent DNA-based chemosensors in pattern-based sensing. We used a set of diverse industrial volatile chemicals to screen and identify a set of five short oligomeric DNA fluorophores on PEG-polystyrene microbeads that could differentiate the entire set after exposure to their vapors in air. We then tested this set of five fluorescent chemosensor compounds for their ability to respond with fluorescence changes when exposed to headgas over soil samples contaminated with one of ten different samples of crude oil, petroleum distillates, fuels, lubricants and additives. Statistical analysis of the quantitative fluorescence change data (as Δ(R,G,B) emission intensities) revealed that these five chemosensors on beads could differentiate all ten product mixtures at 1000 ppm in soil within 30 minutes. Tests of sensitivity with three of the contaminant mixtures showed that they could be detected and differentiated in amounts at least as low as one part per million in soil. The results establish that DNA-polyfluorophores may have practical utility in monitoring the extent and identity of environmental spills and leaks, while they occur and during their remediation.

ベトナム北部のMau Due アンチモン鉱床周辺の重金属元素分布について

ベトナム最北部のMau Due 鉱床はデボン紀の不純なドロマイト質頁岩中の裂罅充填性の輝安鉱鉱床である．その地化学的な研究によると，その鉱化成分は主としてS 及びSb からなり，若干のAs・ベースメタル成分を伴う．土壌中のSb 含有量は変化が激しく，これは鉱石成分の混在によるものと考えられる．雨季 (5−9 月) と乾季 (10−4 月) に分けられた採取試料の分析結果，土壌のSb 平均含有量は雨季932 ppm，乾季342 ppm であって雨季で高く，一方河川堆積物では，雨季2,563 ppm ，乾季2,504 ppm であり，両者で著しく増加する．As はSb と同様な挙動をとり，その含有量は雨季／乾季の土壌において29/26 ppm と，絶対量が少ない．河川堆積物では68-67 ppm に増加するが，この事実はSb，As が微細な硫化物として存在することを示唆している．日本の地向斜帯の堆積岩と比べてベトナムの堆積岩類は，微量成分としてのSb に富んでいる可能性がある．

REMEDIATION OF DIESEL CONTAMINATED SOILS USING SURFACTANTS: COULUMN STUDY

This study presents the experimental remediation studies of diesel contaminated soil with Sodium Deducible Sulfate (SDS) as surfactants using column tests. Sandy selected soil had the grain size distribution of # 40 meshes to the # 200 mesh range. The soil columns were contaminated with adequate diesel amount to achieve the concentration of 10000 and 20000 ppm in soil. 0.1, 0.2, 0.3, 0.4 percent of surfactants and pH values of 4, 7, 9 and 11, were examined. After 72 h, washing began and all tests were continued up to 10 pore volume and the trend of remediation and permeability of soil during the test was investigated. pH and TPH of outlet solution measured during 2, 4, 6 and 10 pore volumes. Times were recorded during 0.67, 1, 1.33, 2, 3.33, 4, 5.67, 6, 7.33, 8, 8.67, 9.33 and 10 pore volumes, in order to calculate permeability values.Results showed that in all states the quantity of remediation for acidic states was very low and efficiency of remediation when using only water was about (1:3) of maximum amount. For soil with initial contaminant concentration of 10000 ppm the maximum efficiency is for surfactant in the concentration of 0.3 and pH = 11 and for soil with initial contamination amount of 20000 ppm the maximum efficiency is for surfactant in the concentration of 0.1 and pH = 11. By increasing the amount of surfactant concentration, the permeability of soil decreased and in pH = 11 the amount of permeability is maximum. With increasing initial contamination quantity rate of increasing of remediation and permeability decreased. Consequently in the low level of contamination the effect of washing solution pH value in soil remediation and permeability is more in comparing with high level of contamination. For initial contamination of 10000 ppm optimum removal efficiency obtained 35% for surfactant of 0.3% and pH = 11. For initial contamination of 20000 ppm, optimum removal efficiency is obtained as 45% for 0.1% of surfactant and pH = 11. Using of higher soil column, sampling from different elevation for investigating remediation trend in height and surveying temperature effect on diesel contaminated soil remediation can help to modification procedure and improvement of efficiency.

Corrosion behaviour of cast iron exposed to Arabian Gulf environment

PurposeThe purpose of this paper is to determine the long‐term corrosion behavior of cast iron coupons in the Jubail Industrial City (JIC), Saudi Arabia.Design/methodology/approachThe samples were exposed under atmospheric, underground, and splash zone conditions, at Khaleej Mardumah Test Station (KMTS) in Jubail. Soil, groundwater, seawater and air particulate samples were collected at the exposure sites and were analyzed. Secondary electron microscopy (SEM), X‐ray diffraction (XRD) and X‐ray fluorescence (XRF) were used to examine the surface morphology of the test coupons and identify the corrosion products developed on the surface of the metals. The corrosion rates of the coupons were determined by weight loss method.FindingsThe results showed that the atmosphere, underground and splash zone conditions all were very corrosive to cast iron, due to temperature and humidity variations as well as the high chloride and sulfate concentrations in the region. The splash zone was the most corrosive regime of the three test zones. The main corrosive ions in the environments were identified as chloride and sulfate. The maximum chloride and sulfate concentrations were measured to be 8.94 and 49.65 μg/m3in atmosphere, 8,040 and 1,410 ppm in soil, and 29,500 and 5,770 mg/l in seawater, respectively. The corrosion rates of cast irons were found to be 343‐536 μm/y in splash zone, 90‐214 μm/y in underground, and 22‐27 μm/y in atmosphere. Compared to other parts of the world, the soil, marine and atmospheric environments at the selected test site are very corrosive.Originality/valueIn this paper, corrosion of cast iron is presented in atmospheric, soil and splash zone conditions along the eastern coast of the Arabian Gulf.