DTPA Extraction Research Articles

Induced Phytomanagement of Multi-Metal Polluted Soil with Conocarpus erectus Supported by Biochar, Lignin, and Citric Acid

Induced heavy metals (HMs) phytoextraction from heavily contaminated soils is challenging, as high HM bioavailability causes phytotoxicity and leaching. This study introduces a novel approach for HM immobilization with biochar (BC) and lignin (LN), and later their controlled mobilization with citric acid (CA) in soil. Conocarpus erectus was grown for 120 days in shooting-range soil (SS) polluted with Pb, Cr, Cd, Ni, and Cu. HM concentrations in parts of the plants, their percentage removal, and leaching from SS were measured. Moreover, plant biochemical parameters such as the contents of chlorophyll a (Chl-a), chlorophyll b (Chl-b), protein, ascorbic acid (AsA), amino acids, and total phenolics, along with biophysical parameters such as relative water content (RWC) and water uptake capacity (WUC), were also inspected. Adding BC, LN, and BC+LN to SS improved biomass, as well as the biophysical and biochemical parameters of plants, while efficiently reducing HM concentrations in plant parts, DTPA extract, and leachates compared to the control (CK). However, the greatest amplifications in plant height (82%), dry weight of root (RDW) (109%), and dry weight of shoot (SDW) (87%), plant health, and soil enzymes were noted with the BC+LN+CA treatment, compared with the CK. Moreover, this treatment resulted in Pb, Cr, Cd, Ni, and Cu removal by 68, 30, 69, 59, and 76% from the SS compared to the CK. Surprisingly, each HM concentration in the leachates with BC+LN+CA was below the critical limits for safer water reuse and agricultural purposes. Initial HM immobilization in HM-polluted soils, followed by their secured mobilization during enhanced phytoextraction, can enhance HM removal and reduce their leaching without compromising plant and soil health.

Comparison of Water and DTPA Extractants for Testing of Greenhouse Soilless Substrates

ABSTRACT The main purpose of this study was to improve the accuracy and reliability of nutrient analysis on soilless substrates by comparing two different saturated medium extract (SME) methods, using either water (SMEW) or DTPA (diethylenetriamine-pentaacetic acid, SMED) as extractants. A series of analyses were performed to compare ion levels quantified from either SMEW or SMED. Substrate pH, electrical conductivity (EC) and nutrient data were analyzed from a survey of substrate components (coconut coir, peat, bark, perlite, vermiculite), and blended greenhouse propagation substrates using the SMEW and SMED methods. In addition, a series of SMEW and SMED extracted samples were sent to three commercial soil testing laboratories for nutrient analysis. The objectives of these analyses were to (1) validate that published relationships between SMEW and SMED methods were consistent with correlation curves for pH, EC and nutrient levels across a wide range of soilless substrates, (2) compare statistical variability of results from SMEW and SMED methods and (3) compare variability in results between different laboratories. The results validated that previously published standards for interpreting SMEW extractions can be used for SMED method for macronutrients and EC due to an approximately 1:1 relationship for test results between extraction methods. Up to 2 orders of magnitude higher levels of micronutrients were extracted for iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu) using SMED compared with SMEW, with low correlation between extractants. Concentrations of ions from SMED extractions were less variable than SMEW for micronutrient analysis but were comparable for macronutrient analysis. Results from this study were combined with published research to provide suggested ranges using SMED for soilless substrates.

Enhancing Lead Passivation in Contaminated Soil: Impacts of the Chemical Modification of Oxygen-Containing Groups (OCGs) on the Surface of Hydrochar

ABSTRACT In this study, we selected walnut shell-derived pristine HC (pHC) and two modified derivatives obtained by oxidative and alkali treatments (designated mHC-O and mHC-A, respectively) to investigate the passivation performance of Pb(II) in contaminated soil. The yields of mHC-A and mHC-O were 70.58% and 95.38%, respectively, after posttreatment. According to the XPS, FTIR, and acidity titration results, the amounts of the three major OCGs (i.e. C−O, C=O, and O−C=O) all increased after H2O2 oxidation. Moreover, chemical modification fundamentally changed the structural characteristics of pHC. DTPA extraction tests indicated that the extractable Pb content after 30 days of incubation decreased by 13.60%, 19.32% and 14.53% at 7% (w/w) doses of HC, mHC-O and mHC-A, respectively, compared to that of the control. Furthermore, mHC-O was superior to pHC and mHC-A in terms of Pb passivation efficiency, which was consistent with the results of BCR sequential extraction and leaching tests using three root exudates. For mHC-O at the 7% dose, the contents of bioavailable Pb in the contaminated soil were 19.85 and 8.83 mg/kg based on DTPA leaching and BCR analysis, respectively, while they were 0.616, 0.564 and 0.07 mg/kg in the root exudate leaching tests of Ophiopogon japonicus, radish and spinach, respectively, indicating that the root exudate leaching method lowered the bioavailable Pb content compared to the DTPA and BCR methods. Overall, Oxidation posttreatment with HC could improve the passivation of Pb in contaminated soils.

Unravelling the impact of soil types on zinc, iron, and selenium concentrations in grains and straw of wheat/Amblyopyrum muticum and wheat/Triticum urartu doubled haploid lines

The concentration of mineral nutrients in plants is associated with bioavailabilities of soil mineral nutrients, which are regulated by various soil physio-chemical properties. A pot experiment was conducted to investigate the effects of soil type on grain and straw zinc (Zn), iron (Fe) and selenium (Se) concentrations of wheat/Amblyopyrum muticum and wheat/Triticum urartu doubled haploid lines. A set of 42 treatments in a factorial combination with 21 genotypes and two soil types collected from Ngabu and Chitedze Research Stations in Malawi was laid in a randomised complete block design (RCBD) in three replicates. Pre-experiment soil Zn and Fe were extracted using DTPA extraction method followed by analysis with inductively coupled plasma-mass spectrometry (ICP-MS). Aqua-regia hotplate acid digestion was used to extract soil Se and analysis was done using ICPM-MS. Grain and straw samples were digested using nitric acid digestion (HNO3) and analysed using ICP-MS. Soil analysis results showed that the two soils had the same textural class (Sandy clay loam), but different mineral concentrations, pH levels and percentage organic matter. Analysis of variance revealed a ~two-fold higher Zn concentration in grains grown in low pH, high Zn soils (Chitedze soils) compared to grains grown in high pH, low Zn soils (Ngabu soils). Variation in grain Zn concentration was associated with the genotypes (p = 0002), soil type (p = <0.0001), and their interaction (p = 0.035). Grain Fe was 1.3-fold higher in low pH than in high pH soils, and it was influenced by genotypes (p = < 0.0001) and soil type (p = <0.0001). Grain Se was highly associated with soil type (p = <0.0001), and it was 30-fold higher in high pH than in low pH soils. Straw Zn was generally higher in plants grown in Chitedze soils than Ngabu soils, whilst straw Se was higher in plants grown in Ngabu soils than Chitedze soils. The findings demonstrate the significance of soil physio-chemical properties for mineral accumulation and distribution to plant parts, thus informing future breeding programs on important considerations on crop genetic biofortification with the three mineral elements.

Bioavailability of Cd in Plantago weldenii and Sonchus oleraceus Plants: The Effects of a Humic and Fulvic Acids-Based Biostimulant

Cadmium (Cd) contamination poses a major threat to plants and human health, as well as to ecosystem services. Biostimulants provide a promising eco-friendly solution to enhance the phytoremediation of Cd-contaminated soils. We examined the influence of a humic and fulvic acids-based biostimulant on two plant species, e.g., Plantago weldenii and Sonchus oleraceus (common sowthistle), in a soil spiked with Cd at 45 mg kg−1. The aim of this study was to determine whether a biostimulant can potentially affect Cd mobility in soil and absorption in plant tissues. We found that the biostimulant significantly decreased Cd bioavailability (recorded as DTPA extractability) in the soil where Plantago was grown from 17.57 to 13.12 mg kg−1, probably due to the Cd immobilization effect of the added biostimulant. However, the biostimulant had the opposite effect in the soil where S. oleraceus was grown (Cd-DTPA significantly increased from 10.13 to 13.03 mg kg−1). S. oleraceus was found to have accumulated higher Cd concentrations in its aerial parts, resulting in a soil-to-plant transfer value close to 1 and root-to-shoot translocation value well above 1. These two indices exhibited the potential of S. oleraceus to be used as hyperaccumulator in Cd-contaminated soils, while P. weldenii behaved rather as a Cd excluder. These findings highlight the complex dynamics of added biostimulants and Cd behavior in soil and plants. We recognize the need for further research so that the mechanisms dictating Cd behavior after biostimulant application can be better elucidated.

Temperature-induced changes in DTPA-extractable trace elements: Predicting the potential impact of climate change on the availability of soil elements

The extraction of trace elements from soil with DTPA is a widely used protocol across laboratories. There is a possible “hidden” discrepancy regarding the results obtained from the extractions, i.e., ambient laboratory temperature and soil properties. In this study, the possible influence of these factors on the extractability of the available forms of Cu, Fe, Pb, Mn, Ni, and Zn, measured with DTPA were studied. Α series of extractions was carried out on a soil sample under normal laboratory temperatures, which fluctuated throughout the year, from 15 to 33.9 °C. In other 144 soil samples, the prevailing physico-chemical properties of soil were evaluated (pH, organic C, clay, CaCO3) that affected the percentage of DTPA extractability relative to the pseudo-total determined content. A strong positive correlation of all metals versus increased ambient temperature was found. Cu had an R2 of 0.897, Fe 0.970, Mn 0.957, Ni 0.938, Pb 0.876, and, Zn 0.922, all highly significant. Extracted Mn exhibited a 6.5-fold increase at the highest temperature of 33.9 οC compared to the lowest. Similar increasing trend was observed for Fe, and Ni, and smaller for Cu, Zn, and Pb. Inherent soil properties affected the percentage of extractability relative to the total content: extractability of Cu, Fe, Mn, and Ni was affected negatively by pH, and the extractability of the studied metals with CaCO3 content. Other soil properties (organic C and clay/sand content) also had an effect, not as pronounced as that of pH and CaCO3. This signifies the necessity of employing standard conditions for routine extractions such as DTPA so that data may be comparable. Also these identified discrepancies may have consequences in the extractability and availability of soil micronutrients and toxic elements regarding climate change. This study aspires to play the role of an initial step towards more robust investigations that would suggest ways of correcting temperature and soil characteristics discrepancies across laboratories.

Influence of biofertilizer on heavy metal bioremediation and enzyme activities in the soil to revealing the potential for sustainable soil restoration

Overuse of chemical fertilizer and pesticides in agricultural activity is frequently damaging to soil health and can accumulate heavy metals in the soil environment, causing harm to plants, humans, and the ecosystem. This study was done to evaluate the effectiveness of biofertilizers in reducing heavy metal levels in contaminated soil and enhancing the activity of soil enzymes that are crucial to plant growth and development. Two bacteria strains, Pseudomonas aeruginosa. and Bacillus firmus, were chosen to develop biofertilizers based on molasses. The pot experiment was setup using a completely randomized design with four treatments and five levels; Bacillus firmus and Pseudomonas aeruginosa were used separately, and they were combined for the biofertilizer dose (20, 40, 60, 80, and 100 mL). Utilizing contaminated soils taken from a greenhouse farm the effect of biofertilizer on heavy metal bioremediation and soil enzyme activity was examined. Methods of soil agrochemical analysis were used to determine the soil physiochemical properties and the concentrations of heavy metals Cu, Fe, Zn, Cd, Mo, Mn, were determined by inductively coupled plasma–mass spectrometry ICP-MS, following DTPA extraction methods. In results, soil pH decreased from 8.28 to 7.39, Ec increased from 0.91 to 1.12, organic matter increased from 18.88 to 20.63 g/kg, N increased gradually from 16.7 to 24.4 mg/kg, and K increased from 145.25 to 201.4 mg/kg. The effect of biofertilizer treatment on soil physiochemical characteristics was significantly positive. Application of biofertilizer significantly increased the heavy metal bioavailability and the activities of soil enzymes. Soil pH were positively correlated with soil Zn (0.99819*), APK (0.95869*) activity and negatively correlated with Fe (0.96759*) also statistically significant at (p < 0.05). The soil Cu positively correlated with Fe (0.99645*), Cd (0.97866*), β.D.GLU (0.99769*) and negatively correlated with PAK (− 0.9624*). Soil ARY had positive correlation with soil Mn (0.99683*), Cd (0.95695*), and negative correlation with PAK (− 0.99424*) at (p < 0.05). Soil enzyme activities were negatively correlated to heavy metals at a significant level. Collectively, the study highlights the potential of biofertilizers as a sustainable and effective approach to enhance soil health and remediate heavy metal-contaminated soils in greenhouses.

Characterization of Technosols for Urban Agriculture

Soil characterization is essential for planning activities in urban areas in order to detect potential risks and understand the possible impacts derived from those activities. Nine soils located in Alicante (southeast of Spain) developed over construction debris were studied. Soil characteristics including mineralogy, elemental composition and metal availability were analyzed in two consecutive years, 2019 and 2020. These soils were similar to forest soils in the same area, with no evidence of asbestos clays or excess harmful elements. However, the use of DTPA extraction revealed high levels of Mn and Zn in some soils. Organic carbon and metals extracted with DTPA differed in 2019 and 2020, but no relationship between metal-DTPA and organic carbon content was observed. In general, organic matter content was higher in 2019, and elements extracted with DTPA were lower. The above-average rainfall in 2019 could have led to the washing away of dissolved materials and fine soil particles, decreasing elemental availability on the one hand, while promoting the development of natural vegetation, increasing soil organic matter, and immobilizing elements in living organisms on the other hand. The fact that the metal mobility varies depending on weather and soil characteristics is important when planning. Despite the demonstrated advantages of increasing urban green areas from an environmental and social point of view, we should not forget the materials on which urban soils are developed. Therefore, it is essential to establish annual plans for monitoring variations in the availability of heavy metals. This is of the most relevance when the plants are for human consumption. It is therefore also necessary to control the vegetables that grow on these soils and, in the event of possible problems, use the soil for gardening.

Comparison between DTPA Extracting Methods for Available Zinc with Multinutrient Extractants in Vertisols and Inceptisols

Aims: To evaluate relationships between some universal soil extractants and legacy methods.&#x0D; Place and Duration of Study: The study was carried out at IISS, Bhopal.&#x0D; Methodology: Samples were analyzed by different methods being related; e.g. GLOSOLAN/international method or rapid methods/universal extractant and legacy methods. Measured data was obtained under the best achievable laboratory quality control conditions, for maximal transfer function reliability with the lowest RMSE (Root Mean Square Error). Out of the 60 samples in each category, a representative set (80% of the samples) was used (e.g. by linear regression analysis) for the development of the transfer function and the rest 20% of the samples were retained for validation of transfer functions. Residuals (differences) between measured and estimated soil property values were calculated. The correlation and RMSE (Root Mean Square Error) were calculated for the validation data set.&#x0D; Results: The Zinc extractable DTPA and Mehlich-3 had a regression coefficient of R2= 0.92. while the extracted with AB DTPA had the regression coefficient of R2= 0.72 with DTPA, with extraction in the order of Mehlich3&gt; AB DTPA&gt; DTPA. Hence, Mehlich-3 and AB-DTPA both extractants can replace DTPA extractants for the determination of available micronutrients in soils in Vertisols.&#x0D; Conclusion: In conclusion, different regression equations are developed between the various methods of analysis that must be used to compare the results obtained from different extraction methods.

Effects of Waste Cement on the Extractability of Cd, Soil Enzyme Activities, Cadmium Accumulation, Activities of Antioxidant Enzymes, and Malondialdehyde (MDA) Content in Lettuce

Waste cement, a common by-product of urban construction, is often wasted in huge quantities and is worthless. However, some studies have confirmed that waste cement can be used as an alternative heavy metal immobilizing agent. Waste cements, derived from hydrated cement mortar products, were evaluated for soil Cd bioavailability by DTPA extraction and for their efficacy in ameliorating the toxicity of cadmium to soil enzymes and plant antioxidant enzymes. Soil incubation and pot experiments were conducted on three types of waste cement (OPC (ordinary Portland cement), FAC (fly ash cement) and ZEC (zeolite cement)) with an application rate of 1%, 2%, and 3%. The addition of OPC, FAC, and ZEC significantly increased the pH and cation exchange capacity of the soil (p &lt; 0.05). The concentration of DTPA-extractable Cd significantly reduced with a consequential decrease in Cd uptake and transport in lettuce. OPC, FAC, and ZEC application significantly (p &lt; 0.05) enhanced FDA hydrolysis and soil urease activity, except for catalase activity. OPC, FAC, and ZEC, when applied to soil, enhanced the total dry biomass (shoots and roots). Furthermore, the activities of guaiacol peroxidase (POD), catalase (CAT) and superoxide dismutase (SOD) declined in lettuce treated with OPC, FAC, and ZEC. With the addition OPC, FAC, and ZEC, the content of MDA in lettuce leaves displayed a remarkable decrease. In conclusion, the waste cements effectively reduced Cd bioavailability and enhanced the antioxidant system of lettuce.

Effects of Straw Removal Measure on Soil Cd Bioavailability and Rice Cd Accumulation

A field experiment was conducted in a lightly Cd-contaminated rice field in Ningxiang City, Hunan Province, to study the effects of straw removal measures on the soil Cd bioavailability and rice Cd accumulation. The results showed that:① two consecutive seasons of straw removal measures (T1-T4 treatments) effectively increased soil pH by 0.04-0.58 units, reduced soil organic matter by 0.68%-25.87%, and reduced the Cd content of rhizosphere soil by 3.76%-12.78%. ② The proportions of Cd in the acid-extractable fraction and oxidizable fraction decreased, and the proportion of Cd in the residual fraction increased. Furthermore, straw removal measures significantly reduced the bioavailability of Cd in rhizosphere soil, and the Cd contents in TCLP, DTPA, and CaCl2 extracts all significantly decreased compared with those in CK. ③ The straw removal measure could significantly reduce the content of DOC and Cd in soil pore water; and the contents of Cd in soil pore water decreased by 4.54%-40.00% and 2.75%-67.34% under the straw removal measure (T1-T4) for two consecutive seasons, respectively, indicating that DOC was one of the key factors affecting the content of Cd in soil pore water. ④ Two consecutive straw removal measures (T1-T4) reduced the accumulation of Cd in different rice tissues, among which, under the treatment of all straw and root removal (T4), the Cd contents of brown rice in late rice planting in 2020 and early rice planting in 2021 decreased by 18.52% and 39.69%, respectively. Therefore, full or partial removal of straw in Cd-contaminated rice fields is a powerful measure to reduce the risk of exceeding Cd levels in brown rice.

Micronutrient Indexing of Soils Located in Attock District of Pakistan: A Guide to Replenish the Nutrient Deficiency

The agricultural land of Attock district falls in Pothwar area of the Punjab Pakistan which is mostly rainfed (barani) and agriculture in the area depends on rainfall which is erratic and scanty. Therefore, soil health becomes more crucial for crop growth while application of micronutrients is negligible in this area. During the years from 2016 to2018, 15,337 soil samples were collected from the district Attack to determine micronutrient status of the soil. These soil samples were analyzed for Zinc (Zn), copper (Cu), Iron (Fe) and Manganse (Mn) using DTPA extraction method while dilute HCl method for Boron (B). The results indicated that nutrient index value of plant available Zn was in the marginal category (1.84) with 30.7% soil samples falling in low, 54.1% in marginal and 15.2% in adequate category. Nutrient index value of plant available Cu was in the adequate category (2.18) with 16.9 % soil samples in low, 47.9% in marginal and 35.2% in adequate category. Nutrient index value of plant available Fe was 1.46 (low) where 76.8% soil samples were found to be low and 23.2% adequate. Nutrient index value of plant available Mn was 1.11 (very low) where 89.3% soil samples were low, 9.9% marginal and only 0.8% adequate. Nutrient index value of plant available B was also in very low category (1.25) with 74.2% soil samples low and 25.8% marginal. The results indicated depletion and low concentration of micronutrient in most soil of Attock district which ultimately urges the use of balanced fertilizer for higher crop yield.

Geospatial Visualization and Ecological Risk Assessment of Heavy Metals in Rice Soil of a Newly Developed Industrial Zone in Bangladesh

With rapid industrialization in Gazipur areas of Bangladesh, untreated industrial effluents have been polluting rice soils which could exert potential ecological risk. Therefore, four different types of industries including chemical (SL), textile and paints (MIX), dyeing (CK), and sweater and dyeing (RD) were selected to monitor the intensity of heavy metal pollution in rice soils and ecological risk assessment. The di-acid digestion method was used for the determination of Pd, Cd, and Ni, and the DTPA extraction method was used for Fe, Zn, and Cu. ArcGIS was used to visualize the spatial patterns of heavy metal pollution, and different pollution indices were calculated to assess the ecological risk. The highest concentration (mg kg−1) of Cd (0.72), Pb (104.20), and Ni (5.02) was found in soils of the MIX industrial area. The highest concentration (mg kg−1) of Fe (147.65) and Zn (11.27) was found in the SL industry, while the highest Cu (7.67) was found in the CK industry. It was evident from the spatial distribution that the soils of paddy fields adjacent to the different industries are more contaminated than background soil. Although the potential ecological risk of heavy metal was low, different pollution indices indicated low to high pollution. Thus, the adjacent rice field soil of different industries is being contaminated by different heavy metals which may raise ecological risk.

Temporal distribution and accumulation pattern of cadmium and arsenic in the actual field calcareous soil-maize system, northwest China

The contrasting chemical behaviors of two toxic elements, arsenic (As) and cadmium (Cd) in co-contamination calcareous soil and its absorption by crops have not been thoroughly explored, especially in the implementation of the measure of prohibiting the use of wastewater to irrigate farmland. We propose that the present environmental characteristics of ecologically fragile areas and appropriate restoration measures are critical determinant of soil remediation. In this study, the typical field farmland irrigated by industrial and domestic wastewater in the Chinese Loess Plateau for >50 years was selected. The results showed that after the sewage irrigation was stopped, the mean contents of Cd (7.09 mg/kg) and As (13.47 mg/kg) in the soil were still rising, which might be a potential input source. The average values of soil risk indices such as the potential ecological risk (PERI = 2394), pollution load index (PLI > 4 for 60 % of studied samples), and degree of contamination (Dc = 86.6) showed severe soil pollution in the study area. The decrease of soil pH, the loss of soil texture and calcium carbonate were found to be the reasons for the high chemical activity of Cd. The bioconcentration factors (< 0.2) and translocation factor (> 1.0) of Cd indicate that corn is an excluder plant and an ideal phytoremediation method. Thus, 20 % of studied samples were higher than maximum permitted levels of Cd in grain, indicating potential related health hazards. On the contrary, As was mainly adsorbed in calcareous soil, and its bioavailability was lower compared with Cd. The difference between DTPA extraction and sequential extraction may be due to the transformation of chemical forms, resulting in unstable fractions increased the bioavailability of toxic elements. Overall, the findings provide new insights for solutions to manage and repair farmlands under the post-wastewater irrigation period.

Reducing soluble lead and cadmium in contaminated soils using dairy cattle waste based vermicompost

Continuous use of synthetic fertilizer can lead to the accumulation of heavy metals in the soil. The use of organic amendment can reduce the solubility of heavy metals such as Pb and Cd in soil. The experiment was undertaken to determine the decline of soluble Pb and Cd in polluted soils treated with dairy cattle waste-based vermicompost. The study used two soil samples; Inceptisols collected from Air Duku Village and Entisol from Beringin Raya Village, Bengkulu, Indonesia. Entisols and Inceptisols contained 2.0 and 0.4 mg kg-1 soluble Pb and 0.7 and 0.8 mg kg-1soluble Cd, respectively. The samples were pretreated with either 100 ppm Pb or Cd. Vermicompost was applied at the rate of 0, 10, 20, and 30 Mg ha-1 on samples of Inceptisols and Entisol, arranged in Completely Randomized Design (CRD). The mixture was incubated for eight weeks. After the incubation ended, the soil sample was analyzed for soluble Pb and Cd using DTPA extraction before detection using Atomic Absorption Spectroscopy. The study resulted that the soluble Pb and Cd significantly reduced with vermicompost treatment, being the lowest was at the rate of 30 Mg ha-1. Furthermore, the decreased soluble Pb and Cd was more substantial in Inceptisols than Entisols. Soluble Pb in both soils was lower than Cd, suggesting a higher retention affinity of the former. This study summarizes that vermicompost at the rate of 30 Mg ha-1 effectively immobilizes Pb and Cd in contaminated soils.

Stabilization of arsenic, antimony, and lead in contaminated soil with montmorillonite modified by ferrihydrite: Efficiency and mechanism

Co-contamination of As, Sb, and Pb in soil has aroused public concern due to their wide application in industries. However, the efficient stabilization materials with simultaneous cations and anions stabilization capacities are still lacking and remain a challenge. Herein, a new type of montmorillonite modified by amorphous ferrihydrite (amFe@Mont) was synthesized and the immobilization performance of amFe@Mont for As, Sb, and Pb in soil was investigated comprehensively, mainly by TCLP, SBET, and DTPA extraction. The stabilization efficiency assessed by TCLP reached 86.28 % for Sb and 94.60 % for Pb after 56 days, and the As could not be detected in the leachate after 10 days. For As, Sb and Pb, the SBET method achieved a reduction of 87.34 %, 54.59 % and 17.59 % respectively. The DTPA extractable content of the metal(loid)s also declined significantly, especially for As. By applying amFe@Mont, the soil properties as well as the bacterial richness and diversity in the soil were obviously improved. The amFe@Mont adsorption data are well fitted to the Langmuir model and the pseudo-second-order model. The principal stabilization mechanisms were ascribed to inner-sphere complexation, surface precipitation and co-precipitation, and structural incorporation into amFe@Mont. This is the first study to exhibit the feasibility of amFe@Mont as an effective and environmentally friendly stabilizer for remediation of As/Sb/Pb co-contaminated soils.

MICRONUTRIENTS (Zn, Cu, Fe, Mn, B) AVAILABILITY STATUS IN THE SOILS OF SARGODHA DISTRICT, PUNJAB, PAKISTAN

&#x0D; &#x0D; &#x0D; Soil micronutrient deficiency is a major factor in achieving the optimal yields of the crops. To find a possible solution for this deficiency is surveying the micronutrient status of soils at a specific site. Thus current research focused on variability of soil properties and indicated the spatial pattern of soil micronutrients in Sargodha district, Punjab, Pakistan. 40000 soil samples were collected through Random soil sampling to assess soil micronutrient status at a depth of 0-15cm. . Soil samples were analysed to measure the soil Zinc (Zn), Copper (Cu), Iron (Fe), Manganese (Mn) by DTPA extraction method and quantified by Flame Atomic Absorption Spectroscopy. Hot-water soluble (HWS) Boron (B) was determined by spectrophotometer. In this study, properties of soil were investigated with the help of statistical and interpolation methods (Kriging). The available Zn, Fe, Cu, Mn and B ranged from 0.1 to 5 mg/kg, 0.2 to 10 mg/kg, 0.1 to 5 mg/kg, 0.2 to 10 mg/kg and 0.1 to 4.74 mg/kg, respectively, with mean value of 0.82 mg/kg, 4.9 mg/kg, 0.87 mg/kg, 4.04 mg/kg and 0.5 mg/kg, respectively, with standard deviation 0.35, 1.9, 0.383, 1.8, and 0.14, respectively. Regarding “Poor” class out of 40,000 analysed samples, 13% samples were deficient in Zn, 0% in Cu, 43% in Fe, 2% in Mn, and 41% in B. Regarding “Marginal” category 63% samples were at marginal deficient/adequate in Zn, 14% in Cu, 0% in Fe, 87% in Mn, and 59% in B. Regarding “Adequate” category, 24% samples were at adequate level in Zn, 86% in Cu, 57% in Fe, 11% in Mn, and 0% in B. The alarming situation was appeared for B which demands immediate mitigating steps to cover up the deficiency and should be incorporated essentially in fertilizer recommendation.&#x0D; &#x0D; &#x0D;

Copper monitoring in vineyard soils of the Tikvesh region, North Macedonia

This research studies the copper contents in vineyard soils under vineyards affected by the long-term use of copper-based fungicides and evaluates the extent of this influence on the super accumulation in the main viniculture growing regions in North Macedonia. The soil samples were taken from individual vineyards located in the Tikvesh region, from two depths: 0-30 and 30-60 cm. At the same time, control samples were collected from each of the visited sites. The control samples were taken from untreated nearby locations under natural conditions in order to determine the background concentrations. The available copper (Cu) contents were analysed on soil samples taken from 100 locations, 50 of which represent vineyard soils (organic and conventional farming) and 50 control samples from nearby forests and sites. The main finding is that the average available copper concentrations are significantly higher in soils under vineyards, compared to the background concentration in control samples, especially in these with organic farming where the use of coper-based fungicides is more intensive. A comparison of the copper contents in vineyards to the background concentrations of control samples clearly confirmed the anthropogenic influence. A significantly very high level of copper (10.70-18.77 mg/kg) was measured in the soil samples from organic farming. The control samples contained a significantly lower concentration of copper, between average 1.39- 1.62 mg/kg (0-30 cm) and 0.68-0.88 mg/kg (30-60 cm). According to the micronutrient rating as related to a soil test with the DTPA extraction reagent (Jones, 2001) applied in this study, a significant potential ecological risk has been noticed in the agricultural soil samples (organic and conventional production).

Availability and chemical associations of cadmium in contaminated tropical soils amended with mineral and organic amendments

A study was performed to evaluate the variation in pH, availability, and chemical associations of Cd in two previously contaminated Latosols amended with mineral and organic amendments. The Latosols were contaminated with Cd and amended with vermicompost, sugarcane f ilter cake, palm kernel pie, lime, phosphate rock, or zeolite. Cadmium availability was evaluated monthly in the contaminated soil/soil amendment mixtures with the DTPA and Mehlich-3 extractants for twelve months of incubation. At the end of this period, a sequential extraction procedure was performed in the mixtures to identify the Cd forms present in the several geochemical fractions. Lime immobilized Cd at a larger extension (60%), being the metal transferred to less available fractions. The Mehlich-3 extractant had a high correlation (0.96**) with the available fraction examined by the sequential extraction procedure. In general, organic amendments produced small ef fects on the f inal pH of soil/soil amendment mixtures as compared with the initial soil pH. Mineral amendments caused enhancement of soil pH and the most pronounced ef fect occurred with the use of lime.

Investigating the role of bentonite clay with different soil amendments to minimize the bioaccumulation of heavy metals in Solanum melongena L. under the irrigation of tannery wastewater.

Wastewater from tanneries is a major source of heavy metals in soil and plants when used for crop irrigation. The unavoidable toxicological effects of this contamination, however, can be minimized through two independent steps discussed in the present study. In the first step, a batch sorption experiment was conducted in which Cr was adsorbed through bentonite clay. For this purpose, DTPA extraction method was used to analyze Cr concentration in the soil after regular time intervals (0.5, 1, 2, 6, 8, 9, 10.5, 11.5, and 20.3 h) which reduced Cr concentration from 38.542 mgL–1 for 30 min to 5.6597 mgL–1 for 20.3 h, respectively, by applying 1% bentonite. An increase in the contact time efficiently allowed soil adsorbent to adsorb maximum Cr from soil samples. In the second step, a pot experiment was conducted with 10 different treatments to improve the physiological and biochemical parameters of the Solanum melongena L. irrigated under tanneries’ wastewater stress. There were four replicates, and the crop was harvested after 30 days of germination. It was seen that the application of wastewater significantly (P < 0.01) reduced growth of Solanum melongena L. by reducing root (77%) and shoot (63%) fresh weight when compared with CFOP (Ce-doped Fe2O3 nanoparticles); chlorophyll a and b (fourfolds) were improved under CFOP application relative to control (CN). However, the deleterious effects of Cr (86%) and Pb (90%) were significantly decreased in shoot through CFOP application relative to CN. Moreover, oxidative damage induced by the tannery’s wastewater stress (P < 0.01) was tolerated by applying different soil amendments. However, results were well pronounced with the application of CFOP which competitively decreased the concentrations of MDA (95%), H2O2 (89%), and CMP (85%) by efficiently triggering the activities of antioxidant defense mechanisms such as APX (threefold), CAT (twofold), and phenolics (75%) in stem relative to CN. Consequently, all the applied amendments (BN, BT, FOP, and CFOP) have shown the ability to efficiently tolerate the tannery’s wastewater stress; results were more pronounced with the addition of CFOP and FOP+BT by improving physiological and biochemical parameters of Solanum melongena L. in an eco-friendly way.