Polyethylene Containers Research Articles

Evaluation and prediction of the physical properties and quality of Jatobá-do-Cerrado seeds processed and stored in different conditions using machine learning models

The conservation of seed quality throughout storage depends on established conditions, monitoring, sampling and laboratory analysis, which are subject to errors and require technical and financial resources. Thus, machine learning techniques can help optimize processes and obtain more accurate results for decision-making regarding the processing and conservation of stored seeds. Therefore, the aim was to assess and predict the physical properties (moisture content, seed mass, length, thickness, width, volume, apparent specific mass, projected area, sphericity, mean diameter, circular area, circularity, drag coefficient), and physicochemical quality (crude protein, ash content, and acidity index) of Jatobá-do-Cerrado seeds under different processing conditions with pulp, without pulp (scarification), without pulp (fermented), and storage conditions at 10 and 23 °C over six months. Data were analyzed on Weka software (Waikato Environment for Knowledge Analysis) version 3.9.5. testing the following models: Pearson correlation, Artificial Neural Networks, decision tree algorithms RepTree and M5P, Random Forest, and Linear Regression. Processing cerrado jatobá seeds by fermentation and storage at 10 °C minimized physical changes and preserved the physicochemical quality of the seeds in polyethylene plastic, glass container, tetrapack, and polyethylene container, over six months. The combination of processing, temperature, and packaging variables for Artificial Neural Networks, RepTree, Random Forest, and M5P algorithms outperformed linear regression, providing higher accuracy rates. Artificial Neural Network and Random Forest models were the best predicting the effects of treatments on changes in physical properties and physicochemical quality of jatobá seed.

Assessing Drug Product Shelf Life Using the Accelerated Stability Assessment Program: A Case Study of a GLPG4399 Capsule Formulation.

Objective: To evaluate and project the shelf life of GLPG4399, an early-phase clinical drug formulation by applying the Accelerated Stability Assessment Program (ASAP) approach. Methods: Forced degradation conditions were implemented to identify the stability-limiting degradation product. The drug and its degradation products were separated using a validated liquid chromatography method. Then, the selected clinical capsule formulation was placed in a glass vial and exposed to accelerated short-term conditions of combinations of high- and low-level heat and humidity in an open state for 5 weeks. The liquid chromatography results were evaluated using the ASAP, which is based on the moisture-modified Arrhenius principle. The resulting data were fitted using a suitable diffusion kinetics method. Results: The developed model was applied to predict the shelf life of the drug product when using clinically appropriate primary packaging (high-density polyethylene container). The derived stability parameters of the moisture-modified Arrhenius equation were the Arrhenius collision frequency, activation energy, and humidity sensitivity constant. The goodness of fit parameters R2 (>0.95) and goodness of prediction Q2 (>0.80) parameters for the selected model were acceptable. The results of the accelerated, short-term stability study were verified against real-time, long-term 12-month data. Conclusions: We demonstrated the application of the ASAP approach to evaluate the shelf life of a GLPG4399 solid capsule formulation. The studied ASAP approach can be extended to evaluate the stability and shelf-life estimations of other early-phase clinical formulations.

Addition of commercial lactic acid bacteria as starter cultures in anaerobic fermentations of Coffea arabica L., in cherry or raisin stages

The objective of this research was to verify the efficiency of adding commercial lactic acid bacteria (LAB) on anaerobic fermentation of (cherry and raisin) arabica Yellow Catuaí coffees, studying the microbiological succession and its influence in modulating sensorial characteristics on their beverages. The study took place in a rural property in Marília region, Sao Paulo State, Brasil, and was performed according to three different treatments: 1) FNC = spontaneous fermentation of cherry coffees; 2) FCBAL = cherry coffee fermentation using Sacco Lyofast SYAB1 BAL; 3) FPBAL = raisin coffee fermentation using Sacco Lyofast SYAB1 BAL. Fermentations occurred in individual (60 liters) high density polyethylene containers, properly sealed to guarantee anaerobic conditions. After a 48-hour fermentation, all the coffee fruits were washed, beans were depulped and dried on suspended terrace until a 12% humidity was observed. Physical, chemical, microbiological and sensory analysis were performed in samples collected from each fermented batch. Fermentation processes of raisin coffees occurred more slowly than fermentations using cherry coffees and resulted in a lesser consumption of soluble solids and in a slower acidification. Fermentation treatments FNC, FCBAL and FPBAL reached the necessary reduction of Enterobateriaceae and molds. The addition of BAL stimulated the growth of yeasts, which are responsible for the inclusion of the most desired flavor. The fermentations conducted in this experiment resulted in coffee beverages that reached notes of specialty coffees (> 80 points). Even though the raisin coffee achieved a lower note than cherry, the LAB inclusion raised it from 77 (non-fermented raisins) to 80 (FPBAL) points. In cherry fruits, FCBAL got 2 points on final comparation to non-fermented cherries. Thus, the inclusion of LAB presented itself beneficial to anaerobic fermentations of cherry or raisin coffees.

Development of a flow diagram for the production of asphalt concrete mixture using polyethylene waste, contaminated with oil products

Large quantities of low-pressure polyethylene containers used for transportation and storage of oil products (motor oils) entail higher environmental risks produced by their utilization or disposal. An urgent scientific task is to search for new ways for utilization of such containers, to involve them in production of new target products without thorough cleaning of waste from contaminants and residues of motor oils. The present study involved crushed containers used for storage and transportation of motor oil in order to explore the possibility of including polyethylene in the production of asphalt concrete mixture. A sample, containing 17.5% of low-pressure polyethylene (contaminated with motor oil by 8% of asphalt mass), and a control sample of asphalt concrete mixture free of polyethylene, were made in order to investigate the change of properties, occurring in the low-pressure polyethylene asphalt concrete. Results. The study assessed main physical and mechanical properties of asphalt concrete samples containing low-pressure polyethylene and motor oil. According to the assessment, a number of properties exceed the values stated in GOST 9128-2013. In addition, the study results included development of technological regulations for producing asphalt concrete mixture with polyethylene as well as the flow diagram for obtaining asphalt concrete mixture. Using polyethylene waste contaminated with motor oil in the production cycle of asphalt concrete mixtures will reduce the consumption of raw materials for asphalt concrete production and the negative impact on the environment.

The preservative effect of the black rice's cold, hot and ultrasonic ethanol extracts on the storage quality of beef patties

SummaryThis work aimed to determine the total anthocyanin and phenolic contents and antioxidant capacity of extracts of the black rice's cold, hot and ultrasonic‐assisted extracts and their preservative effect on the storage quality of beef patties. The three extracts exhibited high anthocyanin, phenolic content and antioxidant capacity, and they were used in beef patties at five treatments (negative control without extract, positive control with 0.01% butylated hydroxytoluene (BHT), 7.5% cold extract, 7.5% hot extract and 7.5% ultrasound‐assisted extract). Raw and cooked beef patties were tested at 0, 3, 6, 9 and 12 days of cold storage in aerobically packaged polyethylene containers regarding pH, oxidative stability, antioxidant capacity and microbial quality. While adding black rice extracts did not influence the proximate composition of raw samples (P > 0.05), it slowed down the pH and lipid oxidation during storage and provided pH and thiobarbituric acid reactive substances (TBARS) stability in all final products. The BHT and treatments with extract indicated a higher 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) value than the negative control. Also, the incorporation of black rice extracts slightly retarded bacterial growth. These results suggest that the black rice extracts at 7.5% can be used effectively to protect beef patties from microbial spoilage and oxidation during cold storage for 12 days.

Impact of Packaging Materials on the Shelf Life of Enriched Aadun (Maize Meal Snack commonly consumed by the Southwestern region of Nigeria)

Optimum condition at 64.80% maize flour, 20% groundnut paste and 13.20 % palm oil was formulated to produced nutritionally enhanced aadun snack. The snack was stored in the different storage materials namely, sweet prayer plant leaves (control) which is usually used by most locals, low density polyethylene (LDPE), high density polyethylene (HDPE) and food grade plastic container (PC). The initial properties (energy, oxidative and sensory properties) of the enhanced aadun (before storage) were investigated and stored in each of the storage materials. The enhanced aadun samples in each storage material were analysed at two weeks interval for eighteen weeks. The results obtained were analysed statistically to examine the effect of the storage material on the aforementioned properties. The results for energy content decreased significantly (P>0.05) in across all the samples stored. The free fatty acid, acid valve and peroxide value increased significantly (P<0.05) in all the storage materials during the storage period but only the samples stored in PC and HDPE were within the recommended limit of FAO (Food and Agricultural Organization) at the end of the storage period. The sensory quality of the control sample was acceptable up to 12 weeks while samples in other storage materials were still acceptable at the end of the storage period under ambient storage condition.

Enhancing Rooting in Morus alba Cuttings: Effects of Indolebutyric Acid and a Commercial Rooting Agent across Branch Positions

Sericulture is the cultivation of silkworms to produce silk using white mulberry leaves (Morus alba L.); thus, the sector's quality production of mulberry seedlings on a large scale is economically important. The production of seedlings through cuttings is the most effective and fastest reproduction method. Still, it can also be enhanced using synthetic rooting agents, increasing the productive potential of white mulberry crops. The current work aims to evaluate the response of cuttings taken from different parts of the branch of M. alba var. Miura (Apical 1, Apical 2, Medial, Basal 1, and Basal 2) and treated with indolebutyric acid (IBA; 500, 1,000, and 1,500 mg L-1) and commercial rooting agent Forth® (10 % v/v), in addition to a control treatment. After treating the branches, they were placed in polyethylene containers filled with substrate and kept in a greenhouse for 70 days. The application of hormones on cuttings of M. alba favored several morpho-agronomic parameters evaluated for the propagules obtained from different positions on the branch. In conclusion, applying 500 or 1,000 mg L-1 of IBA is recommended for the various positions, with Basal 1 and Basal 2 showing higher values ​​in the evaluated parameters than the other positions. The results can help silk breeders optimize white mulberry crop production.

Non-linear plasma protein binding of cannabidiol

BackgroundCannabidiol is highly bound to plasma proteins. Changes in its protein binding can lead to altered unbound plasma concentrations and result in alteration of pharmacological activity of cannabidiol-containing medications. This research has assessed non-linearity of cannabidiol plasma protein binding and the potential effect of tizoxanide on the binding.MethodCannabidiol protein binding was evaluated by ultrafiltration technique. Human plasma was spiked with cannabidiol stock solution to produce samples of various concentrations. For interaction study potential interactant tizoxanide was added in each sample. All samples were processed through Amicon Micropartition system and analyzed by HPLC.ResultsThe study has detected cannabidiol binding to borosilicate glass (9%) and polyethylene plastics (15%). In the interaction study the mean protein unbound fraction of cannabidiol was 0.05 (5%), indicating no binding interaction between cannabidiol and tizoxanide since cannabidiol unbound fraction without tizoxanide was also 5%. The cannabidiol fraction unbound was more than 2-fold greater at high concentrations compared to low concentrations.Conclusiona). At high concentrations cannabidiol plasma protein binding is non-linear. The non-linearity can affect elimination and medicinal effect of cannabidiol drugs. b). Borosilicate and polyethylene containers should be avoided in formulation, packing and administration of cannabidiol-containing medicines to guarantee correct doses. c). Cannabidiol medications can be co-administered with tizoxanide without caution.

Comparison of multiple preservation and digestion methods for determination of tungsten concentrations in environmental media using ICP-MS

Tungsten is an emerging environmental pollutant. However, a proved robust method for preserving and determining the concentrations of tungsten in environmental media is still lacking. This study examined and compared the suitability of classic methods and previously reported tungsten-oriented methods on preserving dissolved tungsten and recovering tungsten from soil/sediment matrix. Tungsten concentrations in the water samples and digestates were then determined by inductively coupled plasma mass spectrometry. Our data showed that the tungsten-oriented HF and alkaline preservatives indeed successfully maintained the stability of dissolved tungsten. Even when preserved using HNO3 or HCl, dissolved tungsten concentrations did not notably change in most of our water samples over the course of ∼4 months. Using glass containers for storing water samples also did not produce much difference from using high-density polyethylene containers. Our data further suggested that the addition of HF in digestion was important for tungsten solubilization from soil/sediment matrix. The digestion methods with HNO3/HCl/HF and HNO3/HF/NH4OH/EDTA both yielded quantitative recoveries of tungsten from certified reference materials and known synthetic samples, while the other tested methods had limited recoveries. The methods validated by this study could be used to accurately determine tungsten concentrations in environmental media and thereby to assess the fate and potential risks of tungsten.

Assessment of perfluorocarboxylic acids in fluorinated high-density polyethylene containers and estimation of potential non-cancer risks associated with anticipated use scenarios

High density polyethylene (HDPE) containers are fluorinated to impart barrier properties that prevent permeation of liquid products filled in the container. The process of fluorination may result in the unintentional formation of certain per- and polyfluoroalkyl substances (PFAS), specifically perfluoroalkyl carboxylic acids (PFCAs), as impurities. This study measured the amounts of PFCAs that may be present in the fluorinated HDPE containers, which could migrate into products stored in these containers. Migration studies were also conducted using water and mineral spirits to estimate the amount of PFCAs that might be found in the products stored in these containers. The migration results were used to conservatively model potential PFCA exposures from use of six product types: indoor-sprayed products, floor products, hand-applied products, manually-sprayed pesticides, hose-end sprayed products, and agricultural (industrial) pesticides. The potential that such uses could result in a non-cancer hazard was assessed by comparing the modeled exposures to both applicable human non-cancer toxicity values and environmental screening levels. Environmental releases were also compared to aquatic and terrestrial predicted no-effect concentrations (PNECs). The results of these analyses indicated no unreasonable non-cancer risk to humans, aquatic species, and terrestrial species from PFCAs in products stored in fluorinated HDPE containers.

Simple and convenient preconcentration procedure for the isotopic analysis of uranium in seawater.

The demand for monitoring anthropogenic U isotopes, 236U and 233U, in seawater will continue to increase due to radioecological issues and the need for tools for environmental dynamics research. In response to this growing demand, herein, a novel and simple method was developed for the collection of U isotopes in seawater, both in the laboratory and field, using a fabric-like amidoxime adsorbent. The results from the adsorption studies showed that the optimum conditions for processing seawater in a glass beaker were as follows: seawater pH 4, amidoxime adsorbent 0.20 mmol per 500 g seawater and an adsorption time of 9 hours. Alternatively, when using a closed polyethylene container in experiments on-board a ship and using the same ratio of adsorbent to seawater as in the beaker experiment in the laboratory, the optimum conditions were as follows: seawater pH 8 and an adsorption time of 24 hours. Under the above-mentioned conditions, more than 95% of the U underwent adsorption in both the beaker and the polyethylene container experiments. In the case of analyte desorption, more than 80% of U in seawater was recovered using 2-3 mol dm-3 HCl or HNO3 as the eluent. Thus, it was concluded that the amidoxime adsorbent can serve as a simple and effective pre-concentration method for the ultra-trace monitoring of U isotopes in seawater.

Effect of root imbibition with selenium and iodine on antioxidant compounds in tomato (Solanum lycopersicum L.) crop

The use of trace elements such as iodine and selenium in agriculture is gaining great importance due to the benefits in plants before different types of biotic or abiotic stress. This research aimed to evaluate the seedling root priming with Na2SeO3 (0, 0,5, 1, 2, 3 mg L-1) and KIO3 (0, 100, 150, 200, 250 mg L-1) on the antioxidant compounds of tomato (Solanum lycopersicum L.) fruits and leaves. The crop was established under greenhouse conditions in 10-L polyethylene containers containing peat moss and perlite 1:1 (v/v), in a randomized complete block experimental design with a 52 factorial arrangement. In the fruits, the Na2SeO3 influenced the GHS, flavonoids, lycopene and β-carotene contents, while the KIO3 influenced the GHS, vitamin C and lycopene contents. The KIO3-Na2SeO3 interactions affected the GSH, phenols, flavonoids, lycopene and β-carotene contents in fruits. In the leaves the GHS content increased with the Na2SeO3, while the GSH, flavonoids, and chlorophyll contents increased with the KIO3 factor and KIO3-Na2SeO3 interactions. The evaluated enzymes in fruits and leaves decreased with the both the KIO3 and Na2SeO3 concentrations. The Na2SeO3 influenced the hydrophilic compounds by ABTS and DPPH, while the KIO3 influenced the hydrophilic compounds by ABTS. In the leaves, the KIO3 influenced the lipophilic compounds by ABTS. The KIO3-Na2SeO3 interactions influenced the hydrophilic compounds by ABTS in both the fruits and leaves. Seedling root imbibition in KIO3 and Na2SeO3 is a method that implemented in the tomato crop presents interesting aspects in the increase of the antioxidant capacity and the non-enzymatic compounds, such as vitamin C, phenols, flavonoids and GSH contents. However, this method presented an inhibition in the antioxidant enzymes.

Effects of Different Container Types on (1→3)-β-D-glucan Recovery.

It has long been known that containers for sample analysis or storage can play a role in endotoxin recovery and have to be taken into account when determining endotoxin concentrations. However, there is little data on the effects of containers regarding (1→3)-β-D-glucan, which plays a role as a contaminant in endotoxin measurements. To determine the effect of the container on (1→3)-β-D-glucan measurements, four different types of containers were investigated at different temperatures and stored for up to 28 days. For short-term storage for 3 h at room temperature, no effect of the container on the (1→3)-β-D-glucan recovery could be observed, but for storage at -20 °C, the results indicate that the storage time and temperature influences (1→3)-β-D-glucan detection. All containers showed a trend of lower recoveries over time, but the polyethylene container showed a significantly lower recovery compared to the other containers. We also showed that freeze/thaw cycles had a strong influence on the recovery of (1→3)-β-D-glucan in polyethylene containers. Our study showed that the container can affect not only the detection of endotoxins but also the detection of (1→3)-β-D-glucans.

Heavy Metals Identification and Detection in Incinerated Bottom Ash from Biomedical Solid Waste in Selected Healthcare Facilities in Douala, Cameroon

Aims: To identify and detect heavy metals in incinerated bottom ash of Biomedical Solid Waste in selected healthcare facilities in Douala, Cameroon.
 Study Design: Cross-sectional fieldwork and laboratory based study design approach that involved quantitative and qualitative data collection methods
 Place and Duration of Study: This study was carried out in the Douala, Littoral region of Cameroon from the month of January 2023 to June 2023.
 Methodology: 5 grams of filtered incinerated bottom ash from BSW were collected from incinerators of the selected healthcare facilities using labeled plastic polyethylene containers and transported to the laboratory for analysis. Samples were air dried and introduced on polypropylene film to the EDX 7000 spectrometer for sensitive analysis.
 Results: Both the quantitative and qualitative concentration percentage of the heavy metals detected from Na to Uranium in each HCF was determined by the EDX 7000 spectrometer device. Zinc had a significant concentration percentage in BDH (7.491±0.009333%), LH (4.255±0.009%), GH (7.506±0.013%), AHD (6,903±0.012%) and Iron had a significant concentration percentage in GOHD (3.669±0.013%).
 Conclusion: It is concluded that improper disposal of incinerated BA from incinerators may pollute the environment and water bodies through leaching into ground water or being carried into water bodies through runoffs, being inhaled in dust from the dump area, and bioaccumulating in plants and animals that stray to the dump site, potentially having a negative impact on the environment and health risks like cancer and respiratory illnesses. Some of the heavy elements found in bottom ash that had been burned during this investigation were above the USEPA-permitted limits. Assuring proper BA disposal through hygienic landfills may help reduce the amount of heavy metals and other toxic elements in the environment, hence safeguarding human health. To prevent additional environmental damage and human exposure to these elements, waste management practices must be improved through BA recycling. Additionally, it is advised that waste managers in the healthcare industry receive training in safe incinerator bottom ash handling and disposal techniques. Regulatory organizations should also oversee and implement policies for bottom ash management in neighborhood healthcare facilities. In Cameroon, a developing nation that must concentrate on environmental challenges that also benefit human health, this study is fundamentally significant. Sustainable prevention of waste and heavy metals in various HCFs will result from source segregation, knowledge of the problem, and safeguards taken at every stage of the waste cycle.

Design and characterization of functional TiO2–lignin fillers used in rotational molded polyethylene containers

In this study, new TiO2–lignin hybrid systems were synthesized and characterized by various methods, including non-invasive backscattering (NIBS), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), elemental analysis (EA) and zeta potential analysis (ZP). The weak hydrogen bonds between the components, as shown on FTIR spectra, proved the production of class I hybrid systems. TiO2–lignin systems were found to display good thermal stability and relatively good homogeneity. These newly designed hybrid materials were used to produce functional composites via rotational molding in a linear low-density polyethylene (LLDPE) matrix at 2.5 % and 5.0 % loading by weight of the fillers, namely, TiO2, TiO2–lignin (5:1 wt./wt.), TiO2–lignin (1:1 wt./wt.), TiO2–lignin (1:5 wt./wt.) and pristine lignin, creating rectangular specimens. The mechanical properties of the specimens were measured via compression testing and by low-energy impact damage testing (the drop test). The results showed that the system containing 5.0 % by weight of TiO2–lignin (1:1 wt./wt.) had the most positive effect on the container's compression strength, while the LLDPE filled with 5.0 % by weight of TiO2–lignin (5:1 wt./wt.) demonstrated the best impact resistance among all the tested composites.

Seed Priming Based on Iodine and Selenium Influences the Nutraceutical Compounds in Tomato (Solanum lycopersicum L.) Crop.

The use of trace elements in agriculture as a complement to crop fertilization programs is a practice that is gaining importance and relevance worldwide. Iodine and selenium perform essential functions in human health, related to the proper functioning of the thyroid gland, acting as antioxidants and antiproliferatives, and their limited intake through food consumption can cause malnutrition, reflected in the abnormal development and growth of humans. This research aimed to evaluate the nutraceutical quality of tomato (Solanum lycopersicum L.) in response to seed priming based on KIO3 (0, 100, 150, 200, 250 mg L-1) and Na2SeO3 (0, 0.5, 1, 2, 3 mg L-1), performed by interaction from a 52-factorial design and by independent factors in a 24-h imbibition time. The tomato crop was established under greenhouse conditions in 10-L polyethylene containers containing peat moss and perlite 1:1 (v/v). Regarding non-enzymatic antioxidant compounds, lycopene, β-carotene and flavonoid contents in tomato fruits significantly increased with KIO3 and Na2SeO3 treatments; however, vitamin C content was negatively affected. KIO3 increased the phenol and chlorophyll-a contents of leaves. In relation to enzymatic activity, KIO3 positively influenced GSH content and PAL activity in tomato fruits. KIO3 also positively influenced GSH content in leaves while negatively affecting PAL and APX activities. Na2SeO3 favored GSH content and GPX activity in tomato fruits and leaves. Na2SeO3 negatively affected the antioxidant capacity of hydrophilic compounds by ABTS in fruits and leaves and favored hydrophilic compounds by DPPH in leaves. Seed imbibition based on KIO3 and Na2SeO3 is a method that is implemented in the tomato crop and presents interesting aspects that favor the nutraceutical quality of tomato fruits, which may contribute to increasing the intake of these minerals in humans through tomato consumption.

Detection of Acanthamoeba spp. in groundwater sources in a rural area in the Philippines.

Research on free-living amoebae (FLA) and its public health implication as an etiologic agent of parasitic infection in humans has recently gained traction in the Philippines. This study aimed to identify potential FLAs in collected groundwater samples from Masinloc, Zambales, Philippines. Fifty-four (54) water samples were collected in 250-mL sterile polyethylene containers by purposive sampling from selected groundwater sources in six (6) barangays of Masinloc. The samples were vacuum filtered through a 1.2-μm pore glass microfiber filter, cultured onto non-nutrient agar (NNA) lawned with Escherichia coli, and observed microscopically for amoebic growth for 14 days using light microscopy. Amoebic growth was observed in 11.1% (6/54) of water samples. DNAs from positive samples were extracted and were made to react with polymerase chain reaction using Acanthamoeba-specific JDP1 (5'-GGCCCAGATCGTTTACCGTGAA-3') and JDP2 (5'-TCTCACAAGCTGCTAGGGAGTCA-3') primers, and universal primer Euk A (5'-AACCTGGTTGATCCTGCCAGT-3') and Euk B (5'-TGATCCTTCTGCAGGTTCACCTAC-3'). The presence of Acanthamoeba genotypes T4, T7, and T11 was confirmed using molecular and phylogenetic analysis. Our results confirmed that groundwater sources from two of six sampling sites (33.3%) in Masinloc, Zambales, were contaminated with potentially pathogenic FLAs. Proper identification of risk factors that may cause contamination consequently leads to the implementation of programs that will prevent future infections.

Determination and Evaluation of Potentially Toxic Heavy Metals in Some Selected Rivers within Ijebu-North, Nigeria

Human health would be at risk if water which is essential for every human activity is contaminated with carcinogenic substances including heavy metals, this present study evaluated potentially toxic metal concentration in some selected rivers in Ijebu-North of Nigeria to determine the concentration of heavy metals and evaluate the pollution index. Ten (10) rivers were randomly selected for the purpose of this study. Samples were collected using a labelled acid pre-cleaned polyethylene container so as avoid wall absorption, the samples were collected from different points at different locations along the course of the river. The samples were filtered, acidified with HNO3 and analysed for heavy metals using Atomic Absorption Spectrometer (AAS). Concentrations of Pb, Ni, Cr and Cu in all the rivers were higher than the WHO limit. However Hg, Cd, Ag, Al, and Mn values are below the recommended values. The contamination factor (C_f) for the Pb varied from 2.18-4.04, Ni varied from 3.0-14.0, Hg was between 0.00-0.03333, Cd was between 0.16667-0.6667, Cr varied between 8.00-48.40, Cu varied between 4.00-12.00, Ag varied between 0.01-0.02, Se varied from 0.05-1.25, Al varied between 0.12-0.46 and Mn varied from 0.020-0.028, Cu values fall within the range of very severe pollution. The results from this study revealed that some rivers within the study area were polluted and recommended for treatment before they can be used domestically and for other purposes.

Radioactive Concentrations in Chemical Fertilizers

Background: The aim of the present study was to determine radioactive concentrations in fertilizers known to contain essential nutrients. Results of this study could be used as basic data to monitor the impact of chemical fertilizers on the environment and public health. Nitrogen fertilizers, calcium fertilizers, sulfur fertilizers, phosphate acid fertilizers, and potassium chloride fertilizers were used in this study.Materials and Methods: Five chemical fertilizers were pulverized, placed in polyethylene containers, and weighed. The time to measure each specimen was set to be 3,600 seconds for a scintillator-based gamma-ray spectroscopy system. Concentration of gamma radionuclide was analyzed based on obtained spectra. At the end of the measurement, the spectrum file was stored and used to calculate radioactive concentrations using a gamma-ray spectrometer software.Results and Discussion: In the nitrogen fertilizer, 3.49 ± 5.71 Bq/kg of <sup>137</sup>Cs, 34.43 ± 7.61 Bq/kg of <sup>134</sup>Cs, and 569.16 ± 91.15 of <sup>40</sup>K were detected whereas <sup>131</sup>I was not detected. In the calcium fertilizer, 5.74 ± 4.40 Bq/kg of <sup>137</sup>Cs (the highest concentration among all fertilizers), 22.37 ± 5.39 Bq/kg of <sup>134</sup>Cs, and 433.67 ± 64.24 Bq/kg of <sup>40</sup>K were detected whereas <sup>131</sup>I was not detected. In the sulfur fertilizer, 347.31 ± 55.73 Bq/kg of <sup>40</sup>K, 19.42 ± 4.53 Bq/kg of <sup>134</sup>Cs, 2.21 ± 3.49 of <sup>137</sup>Cs, and 0.04 ± 0.22 Bq/Kg of <sup>131</sup>I were detected. In the phosphoric acid fertilizer, 70,007.34 ± 844.18 Bq/kg of <sup>40</sup>K (the highest concentration among all fertilizers) and 46.07 ± 70.40 Bq/kg of <sup>134</sup>Cs were detected whereas neither <sup>137</sup>Cs nor <sup>131</sup>I was detected. In the potassium chloride fertilizer, 12,827.92 ± 1542.19 Bq/kg of <sup>40</sup>K was and 94.76 ± 128.79 Bq/kg of <sup>134</sup>Cs were detected whereas neither <sup>137</sup>Cs nor <sup>131</sup>I was detected. The present study examined inorganic fertilizers produced by a single manufacturer. There might be different results according to the country and area from which fertilizers are imported. Further studies about inorganic fertilizers in more detail are needed to create measures to reduce <sup>40</sup>K.Conclusion: Measures are needed to reduce radiation exposure to <sup>40</sup>K contained in fertilizers including phosphoric acid and potassium chloride fertilizers.

Buffer capacity as a method to estimate the dose of liming in acid soils

Objective: The study proposes using the dolomite buffer capacity (BCDolomite) as a method of estimating the lime requirement in soils that agronomically require a pH increase. Design/methodology/approach: In six soil samples with different levels of response to the application of dolomite, the organic matter (OM), the content of sand, silt and clay, pH, K, Ca, Mg and the potential acidity (Al+H) were determined. Assuming an apparent density of 1000 kg/m3 and a volume per hectare of 2000 m3, the soils were placed in polyethylene containers and treated with dolomite in doses equivalent to 0, 750, 1500, 2250 and 3000 kg/ha, establishing the BCDolomite as the inverse of the slope resulting from the relationship between the pH and the dose of dolomite. Results: In soils with low response to the dolomite, the content of clay and OM was 280 and 26 g/kg, respectively, and in high response soils, the content of clay and OM was 240 and 47 g/kg, respectively. In all cases, a simple and direct linear relationship was observed (R2 > 0.85; p < 0.05) in the relationship between pH and dose of dolomite. Limitations on study/implications: The results obtained under controlled conditions show that BCDolomite constitutes a viable method to estimate the lime requirement. Findings/conclusions: The BCDolomite showed sensitivity to the complexity of the clay fraction and to the organic matter in the soil, for which the dolomite requirement is equal to the product of the desired pH increase and the BCDolomite