Metals In Fertilizers Research Articles

Enhanced Cadmium Sensing in Fertilizer Samples using Zeolite-modified Graphite Electrode

The presence of heavy metals in fertilizers poses significant environmental and health risks, necessitating robust detection methods to ensure agricultural sustainability and food safety. This study focuses on synthesizing Na-P1 zeolite from coal fly ash and fumed silica wastes, employing it as a potent modifier in graphite electrodes to enhance the electrochemical detection of cadmium (II) in fertilizer samples. Through meticulous assessment using cyclic voltammetry (CV) in a potential window of −1.2 V to 0.5 V, square wave voltammetry (SWV) in a potential region of −1 V to 0.5 V, and electrochemical impedance spectroscopy (EIS) in a frequency ranging from 100 kHz to 10 mHz under open circuit potential polarization, the electrochemical performance of the zeolite-modified graphite electrode (ZGE) was evaluated. The optimization process involved fine-tuning various parameters such as paste composition, solution pH, scan rate, and analyte concentration. Real sample analysis confirmed the applicability of the method in fertilizer samples. Notably, in an HCl medium (pH = 1.0), the SWV oxidation peak of Cd(II) was observed at −0.56 V (vs SCE) with a deposition time of 20 s and a scan rate of 75 mV∙s−1. The ZGE exhibited a remarkable detection limit of 1 μM, a quantification limit of 5 μM, and a high sensitivity of 6.581 μA/μM.cm2 within a linear detection range of 10−3–10−6 M. These findings highlight the potential utility of Na-P1 zeolite in handheld analytic device manufacturing, offering promising applications in environmental monitoring, resource management, and water and soil resource remediation.

Laser-Induced Breakdown Spectroscopy for Determination of Toxic Metals in Fertilizers: emphasis on Lead

The present work aims to evaluate the content of some toxic metals in chemical and organic fertilizers purchased from local markets in Baghdad, Iraq. The analysis was performed by laser-induced breakdown spectroscopy (LIBS) system. The emission spectral lines of lead (Pb), chromium (Cr), cadmium (Cd) and cobalt (Co) have been recorded to determine the best peak representing each element according to the NIST database. The validity of the LIBS procedure was checked by cross-validating the obtained results using atomic absorption spectroscopy (AAS) with a maximum relative error of 5.3%. Moreover, for qualitative analysis, Pb I 296.64 nm emission line was determined to be superior for the evaluation of lead content in terms of three calibration methods: the external standard (ES), the internal standard (IS), and the multiple linear regression (MLR). The linear correlation coefficient values were : 0.94, 0.97 and 0.992, respectively. LIBS results based on the multiple linear regression (MLR) model have demonstrated better performance and were adopted in the assessment of the Pb content in solid fertilizer samples.

Assessment of Multi-Nutrients and Heavy Metals in Inorganic Fertilizers Widely Used by Indonesian Farmers Using NAA

This research aims to determine the concentration of multi-nutrients and heavy metals and investigate the correlation among them in the seven inorganic fertilizers in Indonesia. Sample analysis was carried out using the NAA method. The highest concentrations of macro-nutrients were K (36.54 %) and Cl (18.09%) found in the KCl sample, while Ca (23.01%) was observed in the TSP sample. In the case of micro-nutrients, the highest concentrations of Se (0.36 mg/kg), Ti (597 mg/kg), Br (1.84%), and Ni (2.46 mg/kg) detected in the NPK sample. Meanwhile, the highest concentrations of Co (19.57 mg/kg) and Na (1.40%) were measured in the ZA sample, while Mg, with the highest concentration of 1.78%, was found in the KMgS sample. The micro-nutrients with the highest concentration detected in the TSP sample were Cr (45.96 mg/kg), Zn (342.6 mg/kg), and Mn (1331 mg/kg). Non-essential elements such as U, V, La, Sb, Sm, Th, Hf, Sr, Cs, Tb, Sc, Rb, Ta, and Eu were also detected in the fertilizer samples with the highest concentrations in the TSP sample. Statistical tests of multi-nutrient and heavy metals concentrations indicated that multi-nutrient and heavy metals in fertilizers are complex.

Effects of nearly four decades of long-term fertilization on the availability, fraction and environmental risk of cadmium and arsenic in red soils

Fertilizers are important for agricultural production because they can effectively promote crop productivity. However, long-term fertilization can cause heavy metal accumulation in soils and crops. This study utilized sequential extraction, the diffusive gradient in the thin films (DGT) technique and risk assessment models to estimate the effects of the longest long-term fertilization (38 years) in China on cadmium (Cd) and arsenic (As) accumulation in soils. The treatments included no fertilization (CK); inorganic nitrogen, phosphorus, and potassium fertilization (NPK); manure fertilization (M); and NPK plus M cofertilization (NPKM). The results indicated that the soils treated with NPKM, M and NPK had significantly increased total and available concentrations of Cd and As after 38 years of long-term fertilization. Cd mainly originates from cattle manure, while As originates from phosphate fertilizer. Sequential extraction results indicated that the application of manure increased the acid/exchangeable fraction (F1) and organic matter-bound fraction (F3) of Cd and As. The risk assessment results showed that the environmental risks of both Cd and As increased during long-term fertilization, and Cd contamination in the soil was at a moderate-high level, while As remained at a relatively low level. According to the calculations of the maximum numbers of years of soil productivity and rice production, Cd was labile and accumulated in the soils, and As was more labile than Cd in terms of accumulating in rice, indicating that the true risk from As in rice is higher than that from Cd. Controlling the heavy metals in fertilizers, mitigating effective amendments, and identifying plant types that accumulate low amounts of contaminants may be good choices for cleaner crop production.

Making of KCl liquid fertilizer from liquid waste manufacture of seaweed and galvanized industry

The seaweed processing industry uses potassium hydroxide (KOH) in the seaweed cooking process, while the galvanized industry uses hydrogen chloride (HCl) in the pickling process. Liquid waste from these two types of industries can cause environmental pollution if not managed properly. This study aims to utilize liquid waste from the seaweed processing industry and galvanized industry into KCl liquid fertilizer as an effort to manage the environment while providing economic value for waste. The quality of liquid waste from the seaweed processing industry, liquid waste from the galvanized industry, KCl liquid fertilizer and the content of heavy metals in fertilizer are analyzed through experimental testing using SNI and AOAC methods. The results showed that liquid waste from the seaweed processing industry can be utilized together with liquid waste from the galvanized industry to produce KCl liquid fertilizer that meets the requirements of SNI 02-2805: 2005 and Minister of Agriculture Regulation Number 43 / Permentan / SR.140 / 8 / 2011. Potassium levels as K2O from KCl liquid fertilizer produced ranged from 727 - 16443 ppm, where the value is higher than the standard according to SNI 02-2805: 2005 of 600 ppm. The content of heavy metals in liquid fertilizer produced meets the requirements of the Minister of Agriculture Regulation No. 43 / Permentan / SR.140 / 8/2011. Consequently the range of heavy metals contained in liquid fertilizer produced by As, Hg, Cd, and Pb is 0.0032 - 0.034 ppm, 0 - 0.0007 ppm, 0.0064 -0.0546 ppm, and 0.0006 - 0.3497 ppm, where the values This is lower than the standard according to Regulation of the Minister of Agriculture No. 43 / Permentan / SR.140 / 8/2011 namely As (max 100 ppm), Hg (max 10 ppm), Cd (max 100 ppm), and Pb (max 500 ppm).

Multivariate linear regression model for source apportionment and health risk assessment of heavy metals from different environmental media

The study evaluated source apportionment of heavy metals in vegetable samples from the potential sources of fertilizer, water and soil samples collected along the Changjiang River delta in China. The results showed that 25.72% of vegetable samples (Brassica chinensis L.) containing Pb, and Cd, Cu, Hg and Zn at relatively serious levels were from soil. Combined with principle component analysis (PCA) and cluster analysis (CA), the results of the spatial distribution of heavy metals in different environmental media indicated that fertilizer, water and soil were the main sources of heavy metals in vegetables. The results of multivariate linear regression (MLR) using partition indexes (P) showed that fertilizer contributed to 38.5%, 40.56%, 46.01%, 53.34% and 65.25% of As, Cd, Cu, Pb and Zn contents in vegetables, respectively. In contrast, 44.58% of As, 32.57% of Hg and 32.83% of Pb in vegetables came from soil and 42.78% of Cd and 66.97% of Hg contents in vegetables came from the irrigation water. The results of PCA and CA verified that MLR using P was suitable for determining source apportionment in a vegetable. A health risk assessment was performed; As, Cd and Pb contributed to more than 75% of the total hazard quotient (THQ) values and total carcinogenic risk values (Risktotal) for adults and children through oral ingestion. More than 70% of the estimated THQ and Risktotal is contributed by water and fertilizer. Therefore, it is necessary to increase efforts in screening limits/levels of heavy metals in fertilizer and irrigation water and prioritize appropriate pollution management strategies.

Comparison of digestion methods to determine heavy metals in fertilizers

The lack of a standard method to regulate heavy metal determination in Brazilian fertilizers and the subsequent use of several digestion methods have produced variations in the results, hampering interpretation. Thus, the aim of this study was to compare the effectiveness of three digestion methods for determination of metals such as Cd, Ni, Pb, and Cr in fertilizers. Samples of 45 fertilizers marketed in northeastern Brazil were used. A fertilizer sample with heavy metal contents certified by the US National Institute of Standards and Technology (NIST) was used as control. The following fertilizers were tested: rock phosphate; organo-mineral fertilizer with rock phosphate; single superphosphate; triple superphosphate; mixed N-P-K fertilizer; and fertilizer with micronutrients. The substances were digested according to the method recommended by the Ministry for Agriculture, Livestock and Supply of Brazil (MAPA) and by the two methods 3051A and 3052 of the United States Environmental Protection Agency (USEPA). By the USEPA method 3052, higher portions of the less soluble metals such as Ni and Pb were recovered, indicating that the conventional digestion methods for fertilizers underestimate the total amount of these elements. The results of the USEPA method 3051A were very similar to those of the method currently used in Brazil (Brasil, 2006). The latter is preferable, in view of the lower cost requirement for acids, a shorter digestion period and greater reproducibility.

Distribution of potentially toxic elements in the Brazilian phosphogypsum and phosphate fertilizers

The Brazilian phosphate fertilizer is obtained by wet reaction of the igneous phosphate rock with concentrated sulphuric acid, giving as final product phosphoric acid and dehydrated calcium sulphate (phosphogypsum) as by-product. Phosphoric acid is the raw material for the production of phosphate fertilizers (SSP, TSP, MAP and DAP). Phosphogypsum waste is stored in stacks, since its level of impurities (metals and radionuclides among others) prevent its safe reutilization. However, part of this waste is used to improve fertility of agricultural soils. The main aim of this paper is to determine the levels of potentially toxic elements in phosphate fertilizers and phosphogypsum produced in Brazil. The elements Co and Cr were analyzed by instrumental neutron activation analysis and As, Cd, Cu, Hg, Ni, Pb, Se and Zn were analyzed by ICP-OES. The results obtained are lower than the limits established by the Brazilian regulatory agency for metals in fertilizers and soil conditioner.

Heavy Metal Composition Of Commercial Fertilizers From Zaria, Northern Nigeria

The heavy metal composition of some commercial fertilizers and soil supplements used in Zaria were analysed. The fertilizers analysed include Liquid Organic fertilizer, Palette Organic fertilizer, Urea, Super phosphate, NPK, some of the soil supplements analysed are cow dung and chicken droppings. Using Atomic Absorption Spectrophotometer (AAS) the following range of heavy metal concentrations were obtained: Cu 3.92-38.14mg/l, Mn 0.057-199.17mg/l, Cr 0.19-2.207mg/l, Zn 1.35-83.12mg/l, Fe 5.00-514.18mg/l, Ni 0.063-149mg/l, Pb 9.86-15.52mg/l, Co 0.26-2.87mg/l.. Super phosphate had the highest abundance of Iron (514.18mg/l). These values were compared to standards for heavy metals in fertilizers and supplements for other countries and were found to be below the limits. Like other countries, it will be important for Nigeria to have set standards for heavy metals levels for fertilizers used in the country.

Concentrations of heavy metals in fly ash from a coal-fired power plant with respect to the new Finnish limit values

In Finland, the new limit values for heavy metals in fertilizers used in agriculture and in forestry came into force in March 2007, and for materials used as earth construction agents, in June 2006. From the utilization point of view, it was notable that the total heavy metal concentrations (Cd, Cu, Pb, Cr, Mo, Zn, As, Ni, Ba, and Hg) in fly ash from a coal-fired power plant were lower than those limit values. The concentrations of the easily soluble elements Ca, Mg, Na, P, and Zn in the fly ash were between 3.5 and 35 times higher than those found in the coarse mineral soils of Finland. Fly ash is a potential agent for soil remediation and for improving soil fertility. If inorganic materials and by-products are utilized in earthworks, the content of harmful compounds must be low and the harmful components must be tightly bound to the matrix. Therefore, a five-stage sequential extraction procedure was used to evaluate the extractability of different elements in fly ash into the following fractions: (1) the water-soluble fraction, (2) the exchangeable fraction (CH3COOH), (3) the easily reduced fraction (NH2OH-HCl), (4) the oxidizable fraction (H2O2 + CH3COONH4), and (5) the residual fraction (HF + HNO3 + HCl).

Concentrations of heavy metals in NPK fertilizers imported in Serbia

Concentrations of Pb, Cd, Cu and Mn in sixteen NPK fertilizers imported and widely used in Serbia were determined by flame atomic absorption spectrometry (AAS). The results show that contents of heavy metals varied significantly in different fertilizers depending on N:P:K ratio and fertilizer origin. Pb and Cd contents in water solution of fertilizers occurred at low ranges: 2.0-3.1 and 0.03-1.56 mg/kg, respectively. An NPK (15:15:15) fertilizer from Romania was found to contain the highest concentration of Pb and Cd as impurities. Cu content, ranging from 7.1 to 974.7 mg/kg, was the highest in colored fertilizers from Hungary, the Netherlands and Greece. Mn value in a Hungarian NPK product (10:10:20) exceeds the average Mn value in soil. The data indicate variable contents of heavy metals in fertilizers, some of which are significantly higher than natural concentrations in soil, which suggests that they need to be continuously monitored.

Fertilizer characterization: isotopic data (N, S, O, C, and Sr).

A detailed isotopic characterization (delta15N(Ntotal), delta15N(NO3), delta18O(NO3), delta34S(SO4), delta18O(SO4), (delta13C(Ctotal), and 87Sr/86Sr) of 27 commercial fertilizers used in Spain is presented in this paper. Results together with a compilation of fertilizer isotopic published data are used for two purposes: (i) to identify the origin of the primary constituents and raw materials used in fertilizer manufacture and relate these data with their heavy metals and rare earth elements (REE) contents; (ii) to compare the fertilizer isotopic signatures with natural values and other anthropogenic pollutants and evaluate the usefulness of multi-isotopic analyses to trace fertilizer contaminations in future study cases. Isotope data permit us to know, in most cases, the origin of the primary constituents of fertilizers, and the 87Sr/86Sr ratio distinguishes the origin of the phosphate content--phosphorites or carbonatites--which in turn implies a qualitatively defined and potentially contaminant presence of REE and heavy metals in fertilizers. Delta15N, delta34S, and 87Sr/86Sr have already been used to trace fertilizer contaminations. Their utility can be improved by the coupled use of delta15N(NO3)-delta18O(NO3) and delta34S(SO4)-delta18O(SO4) to evaluate the fractionation processes that can affect contaminants. Moreover, multi-isotopic analyses, using heavy isotopes, allow us to see beyond the fractionation effects to the fertilizer stable isotope signatures and a better distinction from other anthropogenic contaminants.

Alarm over recylced metals in fertilizers kicks off review

Alarm over recylced metals in fertilizers kicks off review

A study of the atomic absorption determination of some important heavy metals in fertilizers and domestic sewage plant sludges.

Abstract An atomic absorption method is described for the rapid analysis of sewage sludges and processed sewage fertilizers. Extensive data is given to allow an evaluation of the reliability of the method. Results are given for the analyses of sludge and fertilizer samples to show the surprisingly high levels of metals in some of these materials.