Phosphate Rock Research Articles

Effect of Mycorrhizae, Azotobacter and Vermicompost Tea on Nitrogen, Phosphorus, and Potassium (NPK) Concentrations in Soil and Cucumber Plants (Cucumis sativus)

An experiment was carried out inside a greenhouse (sandy loam soil) at the College of Agriculture / University of Anbar to investigate the effect of Vesicular-Arbuscular Mycorrhizaee, Azotobacterchroococcum and Vermicompost tea on the concentration of NPK macronutrients in soil and cucumber plants. A factorial experiment consisting of two factors was designed for this purpose: the first factor is a combination of mycorrhizae (M) with 35 g plant−1, azotobacter (A) bacteria 16 ml plant−1 with a microbial density of 2.2 x 109 cfu ml−1 and phosphate Rock (R) with 40 g plant−1, added with half of the mineral fertilizer recommendation each individually with its interactions, the second factor is the addition of three concentrations (0, 5, 10%) of vermicompost tea sprayed on the plant. The experiment was designed with a completely randomized block design (RCBD) with three replications. Cucumber seeds were planted on 15/9/2022 and service operations were conducted for the crop and the experiment continued until 15/12/2022. The result showed highest percentage of phosphorus in the leaves (PIL) (0.40%), the highest potassium in the leaves (KL) (1.95%), followed by the treatment of adding mycorrhizae with phosphate Rock and half the mineral recommendation (MR) with vermicompost tea at a concentration of 10%, then the treatment of adding mycorrhizae with azotobacter bacteria with half the mineral recommendation (AR) with 10% of vermicompost tea, then the treatment of mycorrhizae with phosphate Rock plus half the fertilizer recommendation (MR) with 10% of vermicompost tea, then the treatment of mycorrhizae with azotobacter plus half of the fertilizer recommendation (MA) with 10% of vermicombe tea.

The Effect of Biofertilizers, Phosphorus Sources and Vermicompost on the Preparation of Bacterial and Fungal Cells for the Two Phases of Vegetative Growth and Flowering of Potato Plants

A field experiment was conducted for potato plants in the field of Agricultural Research and Experiment Station in Al-Muradiyya of the Directorate of Agriculture of Babylon - Babylon Governorate for the agricultural season 2022 to study the effect of adding bacterial fertilizer, phosphorus sources (triple superphosphate and phosphate rock) and vermicompost and the interaction between them in cell preparation Bacterial and fungal phases of potato plant vegetative growth and blooming according to RCBD design. The experiment included three factors: the addition of the bacterial biofertilizer Bacillus megaterium (with or without addition), phosphorus sources at three levels (0, triple superphosphate at 100 kg ha-1, phosphate rock at 200 kg ha-1), and vermicompost at three levels. Levels (0, 8, 12) ton ha-1, with three replications, yielded 54 experimental units. Burin cultivar potato tubers were planted, and the results were: The addition of bacterial bio fertilizer to treatment B1 produced the highest numbers of bacterial cells for the two stages of vegetative growth and flowering of potato plants: 4.73×106 and 6.73×106 (colony forming unit g-1 dry soil × 106) in sequence, and 5.93 × 103 and 12.15 × 103 for fungal cells. g-1 dry soil × 103, sequentially. During potato plant vegetative growth and flowering, the P22 treatment had the most bacterial and fungal cells, at 5.31 × 106 and 7.56 × 106 (colony forming unit g-1 dry soil 106), respectively. sequentially (g-1 dry soil) 103. Treatment F2 with vermicompost added had the largest counts of bacterial and fungal cells during the vegetative growth and blooming phases of potato plants at 6.22 × 106 (colony forming unit g-1 dry soil 106) and 10.08 × 106 (colony forming unit g-1 dry soil 103), respectively. B1P2F3 had the greatest bacterial cell counts at 8.25 and 13.55 × 106 (colony forming unit g-1 dry soil 106).

Effect of Bio fertilization and Phosphate Rock under Sterilization Conditions on the Activity of Phosphatase Enzyme, Phosphorus Availability and Growth of Wheat Plant Triticum aestivum L.

Effect of Bio fertilization and Phosphate Rock under Sterilization Conditions on the Activity of Phosphatase Enzyme, Phosphorus Availability and Growth of Wheat Plant Triticum aestivum L.

Uranium recovery from phosphate rocks/minerals – A comprehensive review

Although the use of nuclear energy is still viewed with caution due to various problems associated, such as the safe operation of 'aging' nuclear plants and the final disposal of nuclear waste, many countries in Europe are now increasingly considering nuclear energy as an alternative to reducing fossil fuel energy production. At the present stage primary sources of uranium are sufficient to meet uranium needs and secondary sources are becoming increasingly important in terms of their long-term availability and environmental friendliness. Mining/recovery of uranium from secondary sources (such as phosphate minerals) is considerably safer in terms of exposure to radiological radiation and therefore requires less stringent safety measures. Uranium is also present in waste produced from certain industrial processes such as fertilizer production industry (e.g. phoshogypsum) and in nuclear waste. This work refers to the extraction and recovery of uranium from phosphate rocks, which is directly related to the production of uranium-free phosphate fertilizers and aims to limit environmental pollution related to the use of phosphate fertilizers. Since the chemistry during the leaching step is critical to efficient uranium recovery, various investigations have been carried to study various parameters that play an important role in achieving an optimum uranium extraction from rocks. Uranium leaching is carried out under acidic or alkaline conditions and the choice of chemistry is determined by the mineralogy of the host rocks. Acid leaching yields a higher recovery than alkaline leaching because the matrix is often more resistant to alkali than to acid leaching. However, the alkaline leaching process has the advantage of leading to the precipitation of a comparatively purer product directly from the leaching liquid. In addition, the washing solutions can be regenerated for further use, making this method more environmentally friendly. Recently alternative methods have been proposed which make use of uranium complexing ligands (e.g. EDTA) to achieve more efficient and selective uranium recovery.

Assessment of Heavy Metal Content and Consumption Risks At Selected Paddy Field in Malaysia: A Review

As the Malaysian population grows, there is a high demand for rice, the main staple food in this region. This has caused the overuse of agrochemicals that contain heavy metals and the utilization of contaminated groundwater to increase paddy yield, posing a risk to humans. This study reviewed the accumulated heavy metals in paddy fields of Malaysia's Selangor, Kedah and Sabah states and further calculated the consumption risks of rice grains from the selected areas. The study revealed that paddy soil in Ranau Valley (Sabah), Kota Marudu (Sabah) and Tanjung Karang (Selangor) showed presences of Cu and Cd in high concentration, respectively, creating higher potential to be uptake by paddy roots. These findings also revealed that Ranau Valley (Sabah) paddy grains contained high Cu and Cd concentrations, while Sabak Bernam (Selangor) contained high Pb concentrations. Further, a higher Cd concentration was reported from the Ranau Valley (Sabah), while the higher Pb concentrations were reported from the samples collected from Sabak Bernam (Selangor), Tanjung Karang (Selangor) and Kubang Pasu (Kedah). Based on the health risk indices calculation in this study, carcinogenic and non-carcinogenic health risks in all study areas except in Kubang Pasu (Kedah) and Langkawi (Kedah) are likely to occur due to Cu mining activities, ultrabasic soil contamination, utilization of contaminated groundwater and rock phosphate fertilizer and vehicular emission. Regular assessment of heavy metal content and consumption risks of paddy is essential to ensure the paddy field is free from contamination and will help protect the ecosystem and human health.

Design of reactors for leaching phosphatic ore

Phosphoric acid is a product of extreme importance to society, where it is integrated into the food, agricultural, pharmaceutical, and chemical markets. Its acquisition is made from phosphate rocks, which through the leaching step of phosphorus by sulfuric acid, being the solvent, forms H3PO4 and CaSO4. This study aims to present a methodology for reactor design for phosphoric acid, with leaching of phosphate ores, using P2O5 conversion equations and adjusting the Michaelis-Menten model. The type of reactor designed for the process was the CSTR, where it is possible to achieve the conversion goal of 98.5 – 99.5% P2O5, taking into account that the material inside the reactor renews itself four times and the residence time that was specified through modeling, finding a residence time of 4 hours. The initial considerations show that the Michaelis-Menten model fits well for the CSTR reactor design, and that the applied methodology is consistent and brings a wealth of information regarding the behavior of the fluid inside the reactor.

Barley Growth and Phosphorus Uptake in Response to Inoculation with Arbuscular Mycorrhizal Fungi and Phosphorus Solubilizing Bacteria

ABSTRACT Biostimulants and bioinoculants offer the potential to enhance nutrient use efficiency within agricultural cropping systems and thus reduce the amount of mineral fertilizers needed to support crop growth. Considerable uncertainty, however, exists about their efficacy under different management regimes. The present field-based study investigated the effects of phosphorus (P) solubilizing bacteria (PSB) and mycorrhizal (AMF) inoculants in the presence of a range of mineral-based P fertilizers, including triple superphosphate (TSP), struvite and rock phosphate (RP), on the growth, yield, and P uptake of barley (Hordeum vulgare L.). Two consecutive field experiments performed in a low P soil (Eutric Cambisol) revealed that the bioinoculants (PSB and AMF) promoted plant P uptake and grain yield. Moreover, in comparison to P fertilizers lacking bio-inoculants, the application of external P sources combined with bio-inoculants led to significant increases in leaf P concentration, total P uptake, plant dry matter, grain P concentration, and crop yield. Grain yield significantly correlated with P uptake by roots and above-ground parts (i.e. stems, leaves, and spikes) as well as grain P concentration in both seasons. It is concluded that bioinoculants can help improve sustainable P use ultimately leading to greater sustainability of cropping systems and resilience in soil P cycling.

Influence of soil fertility management technologies on phosphorus fractions, sorption characteristics, and use efficiency in humic Nitisols of Upper Eastern Kenya

Fractions of phosphorus (P) and its sorption characteristics are affected by different soil fertility (FM) technologies which ultimately affect crop growth and productivity. However, the response of P fractions and sorption characteristics to soil fertility technologies that integrate diverse amendments is still poorly understood in acidic Nitisols. A randomized complete block design was layout in an acidic Nitisol to determine fractions of P, its sorption characteristics and use efficiencies in acidic Nitisols under various FM technologies in field conditions. The use of minimum tillage + maize residue + inorganic fertilizer + goat manure (MTCrGF) had the highest impact on and significantly increased resin-Pi, NaHCO3-Pi, and maximum P sorption (Smax) by 182, 76, and 52 mg P kg−1. Moreover, NaOH-Pi and Smax concentrations were higher under conventional tillage + maize residue + inorganic fertilizer + goat manure (CTCrGF) by 216 mg P kg−1 and 49 mg P kg−1 than the control. MTCrGF and CTCrGF also had the lowest P bonding energy (0.04 L mg−1). CTCrGF had the highest P partial productivity factor (0.093 and 0.140 kg biomass kg−1 P) and P agronomic efficiency (0.080 and 0.073 kg biomass kg−1 P) during the two cropping seasons. The results demonstrate the positive influence of combining multiple P sources on soil P fractions, sorption characteristics, and use efficiencies. Notably, combining either conventional or minimum tillage with maize straw and applying integrated manure and inorganic fertilizer (MTCrGF or CTCrGF) can increase the labile P concentrations and reduce the potential depletion of the non-renewable rock phosphate and the use of inorganic phosphatic fertilizers for agricultural production.

Total Phosphorous and Mineral Content Determination in Rock Phosphates using ICP-MS

ABSTRACT Phosphorous (P) is an essential element for plant growth and development, and its scarcity is a severe crop output constraint. Determination of total P in soil and fertilizers is very important in agriculture as the amount of P is related to crop production. Rock phosphate (RP) is an excellent natural source of P widely used for P fertilizer production. The objective of this study was to compare two different digestion methods, microwave digestion and hot plate digestion, and to evaluate the performance of two analytical techniques, inductively coupled plasma mass spectroscopy (ICP-MS) and colorimetry (UV-VIS), for measuring total P in imported RP samples. The validation of microwave digestion followed by analysis in ICP-MS was performed. Phosphorus has detection and quantification limits of 1 mg L−1 and 5 mg L−1 respectively through ICP-MS analysis. Average P recovery was found 92.12–96.53%. Precision in terms of intra-day (%RSDR = 2.76–5.98 evaluated using ICP-MS) and inter-day (%RSDr = 2.92–6.75) were found to be within the acceptable range (20%), indicating consistency of the proposed method to determine total-P over traditional UV-VIS method. The combination of microwave-assisted digestion and ICP-MS offers superior efficiency in determining both phosphorus (P) and heavy metals, including aluminum, iron, zinc, cadmium, strontium, manganese and chromium, in RP samples. Hence, this method is novel and rapid and is used for the quantification of total P in different RP samples for quality control.

Agronomic efficiency of rock phosphates used alone or associated with soluble source of phosphorus for corn and common bean crops cultivated in succession under no-tillage and irrigated system.

Agronomic efficiency of rock phosphates used alone or associated with soluble source of phosphorus for corn and common bean crops cultivated in succession under no-tillage and irrigated system.

Can crop yields be secured while reducing phosphorus accumulation in soil? Assessing decades of contrasting fertilizer strategies.

ContextA balanced phosphorus (P) use in agriculture, where P fertilizer input matches crop offtake, is necessary to avoid accumulation of P in soil that is a chronic source for diffuse P loss. Moreover, mineral P fertilizers produced from rock phosphate is a limited resource, and identification of alternative P fertilizer sources such as animal manures that secure yields without P surpluses is therefore essential for sustainable P use. ObjectiveThe objective was to explore crop productivity and soil P accumulation after long-term input of different P fertilizer sources. Moreover, Olsen-P contents in soil were determined to evaluate if crop yields and P balances were reflected in measures of available P. MethodsOn a coarse sandy soil installed in lysimeters under field conditions, crop yields and P surpluses from 1992 to 2022 were quantified as affected by P fertilizer source (annual additions of solid pig manure, pig slurry and mineral fertilizer) since 1975. All lysimeters received mineral nitrogen (N) fertilizers according to the crop demand. Olsen-P contents in the upper soil layer (0–25 cm) were measured over three decades, and vertical distribution of P in soil down to 140 cm depth was studied at the end of the experimental period. ResultsFor oats, barley, pea and beet root, long-term fertilization with solid pig manure at a rate of 15 kg P ha-1 year-1 resulted in similar yields as after fertilization with 30 kg mineral P ha-1 year-1. After 30 years, the build-up of P in soil was much lower after solid pig manure inputs (accumulation of 8 kg P ha-1) than after mineral P fertilization (accumulation of 51 and 434 kg P ha-1 in soil receiving 15 and 30 kg mineral P ha-1 year-1, respectively). The long-term fertilizer treatments affected Olsen-P levels in the upper soil layer with highest Olsen-P contents (>40 mg P kg-1) after fertilization with 30 kg mineral P ha-1 year-1. Only maize benefitted from high Olsen-P levels and generous input of mineral P, whereas the yield potential for the other crop types could be reached at low to moderate Olsen-P levels after long-term additions of solid pig manure. More P was found in the deep soil layers (65–140 cm) after addition of pig slurry than solid pig manure. ConclusionsThe results showed that solid pig manure was a valuable P source that had the potential to replace mineral P fertilizers without compromising crop productivity, while ensuring low P surpluses. ImplicationsThis study suggests that the Olsen-P test could not stand alone in predicting P requirement but should preferably be supplemented with knowledge on fertilizer source, crop type and P offtakes to ensure a more balanced fertilizer P use.

Advances for Improving Phosphorus Use Efficiency in Agriculture

An impending crisis is the continuous availability of phosphate fertilizers, which underlie global food production. The rock phosphate deposits on which the world depends are not only finite but many are polluted and many are located in geopolitically unstable locations, implying that significant changes will be required to maintain food supply for an increasing global population. There is no single solution, but a combination of phosphorus management measures is required not just to extend the life of the remaining non-renewable rock phosphate sources, but also to result in a more efficient, sustainable phosphorus cycle. Improving the effectiveness of fertilizer applications to agricultural land, as well as a better understanding of phosphorus cycling in soil-plant systems and the interplay between soil physics, chemistry and biology in conjunction with plant characteristics are among the solutions. The finite nature of rock phosphate supply and the development of other sources of phosphorus fertilizers is unavoidable. There are clear prospects and it is now critical to prioritize a concerted effort to increase phosphorus usage efficiency.

Aluminium dross waste utilization for phosphate removal and recovery from aqueous environment: Operational feasibility development

The need to minimize eutrophication in water bodies and the shortage of phosphate rock reserves has stimulated the search for sequestration and recovery of phosphate from alternative sources, including wastewater. In this study, aluminium dross (AD), a smelting industry waste/by-product, was converted to high-value material by encapsulation in calcium alginate (Ca-Alg) beads, viz. Ca-Alg-AD and utilized for adsorptive/uptake removal and phosphate recovery from an aqueous environment. Encapsulation of AD in alginate beads solves serious operational difficulties of using raw AD material directly due to density difference constraining efficient contact of AD with pollutants present in water and post-treatment recovery of AD material. The phosphate removal was evaluated in both batch and continuous flow operation modes. The batch adsorption study revealed 96.86% phosphate removal from 10 mg L−1 of initial phosphate concentration in 70 min of optimal contact time. Further, the phosphate removal potential of Ca-Alg-AD beads turned out to be independent of solution pH, with an average of 95.93 ± 1.40 % phosphate removal in the 2–9 pH range. The result reflects phosphate adsorption on Ca-Alg-AD beads following a second-order pseudo-kinetic model. Ca-Alg-AD beads-based adsorption followed Freundlich and Langmuir isotherm models. Further, a continuous packed bed column study revealed a total phosphate adsorption capacity of 1.089 mg g−1. The chemical composition, physical stability, and surface properties of Ca-Alg-AD beads were analyzed by means of state-of-the-art analytical techniques, such as Scanning Electron Microscopy-Energy Dispersive X-ray spectroscopy (SEM-EDX), Fourier Transform Infrared Spectroscopy (FTIR) and thermogravimetry/Differential Thermal Analysis (TG/DTA). These characterization techniques comprehend the mechanism and influence of surface properties and morphology on the phosphate adsorption behaviour, which induce the involvement of multiple mechanisms such as ligand complexation, ion exchange, and electrostatic attraction for phosphate adsorption on Ca-Alg-AD beads.

Healed ORIF in a fibula fracture – Hardware removal or hardware retention for the fibula in a patient with minor symptoms?

- A 31yo female is involved in a fall while climbing on some wet rocks. She was brought into the emergency department and was found to have suffered a closed fracture of the right fibula with a deltoid ligament injury. Distal neurovascular exam was normal. She is otherwise unhurt. She had ORIF of her ankle injury and it has gone onto heal with good results. She comes back at 6 months and complains of vague pain over her lateral ankle and hardware with a normal physical exam. She wonders about hardware removal, (Figs. 1 and 2). PAST MEDICAL HISTORY: - previous history of breast reduction surgery and she has delivered one child vaginally. No chronic diseases and she takes no pills except the birth control pill. SOCIAL HISTORY: - married with one child and works as an administrative assistant for a manufacturing company; she is a social drinker and nonsmoker. Has a history of using some recreational drugs but none for 10 years. She is moderately active.

Numerical investigation of closed-loop geothermal systems in deep geothermal reservoirs

Closed-loop geothermal systems (CLGSs) rely on circulation of a heat transfer fluid in a closed-loop design without penetrating the reservoir to extract subsurface heat and bring it to the surface. We developed and applied numerical models to study u-shaped and coaxial CLGSs in hot-dry-rock over a more comprehensive parameter space than has been studied before, including water and supercritical CO2 (sCO2) as working fluids. An economic analysis of each realization was performed to evaluate the levelized cost of heat (LCOH) for direct heating application and levelized cost of electricity (LCOE) for electrical power generation. The results of the parameter study, composed of 2.5 million simulations, combined with a plant and economic model comprise the backbone of a publicly accessible web application that can be used to query, analyze, and plot outlet states, thermal and mechanical power output, and LCOH/LCOE, thereby facilitating feasibility studies led by potential developers, geothermal scientists, or the general public (https://gdr.openei.org/submissions/1473). Our results indicate competitive LCOH can be achieved; however, competitive LCOE cannot be achieved without significant reductions in drilling costs. We also present a site-based case study for multi-lateral systems and discuss how our comprehensive single-lateral analyses can be applied to approximate multi-lateral CLGSs. Looking beyond hot-dry-rock, we detail CLGS studies in permeable wet rock, albeit for a more limited parameter space, indicating that reservoir permeability of greater than 250 mD is necessary to significantly improve CLGS power production, and that reservoir temperatures greater than 200 °C, achieved by going to greater depths (∼3–4 km), may significantly enhance power production.

Effect of Mycorrhizae, Azotobacter and Vermicompost tea on Nitrogen, Phosphorus, and Potassium (NPK) Concentrations in Soil and Cucumber Plants (Cucumis sativus)

An experiment was carried out inside a greenhouse (sandy loam soil) at the College of Agriculture / University of Anbar to investigate the effect of Vesicular-Arbuscular Mycorrhizaee, Azotobacterchroococcum and Vermicompost tea on the concentration of NPK macronutrients in soil and cucumber plants. A factorial experiment consisting of two factors was designed for this purpose: the first factor is a combination of mycorrhizae (M) with 35 g plant-1, azotobacter (A) bacteria 16 ml plant-1 with a microbial density of 2.2 x 109 cfu ml-1 and phosphate Rock (R) with 40 g plant-1, added with half of the mineral fertilizer recommendation each individually with its interactions, The second factor is the addition of three concentrations (0, 5, 10%) of vermicompost tea sprayed on the plant. The experiment was designed with a completely randomized block design (RCBD) with three replications. Cucumber seeds were planted on 15/9/2022 and service operations were conducted for the crop and the experiment continued until 15/12/2022. Concentrations of nutrients were measured in the soil after harvesting the crop as well as in the leaves of the plant. The results of the research proved that the use of mycorrhizae, azotobacter bacteria and phosphate Rock with half the mineral recommendation (MAR) and spraying vermicompost tea at a concentration of 10% are the best in increasing the concentration of nutrients in the soil and plant and revealed significant differences compared to mycorrhizae or azotobacter or vermicompost tea individually, so this treatment gave the highest concentration of available nitrogen (AN) (56.37 mg kg-1 soil), the highest available phosphorus (AP) (16.34 mg kg-1 soil), the highest available potassium (230.3 mg kg-1 soil), and gave the highest percentage of nitrogen in the leaves (NIL) (2.80%), The highest percentage of phosphorus in the leaves (PIL) (0.40%), the highest potassium in the leaves (KL) (1.95%), followed by the treatment of adding mycorrhizae with phosphate Rock and half the mineral recommendation (MR) with vermicompost tea at a concentration of 10%, then the treatment of adding mycorrhizae with azotobacter bacteria with half the mineral recommendation (AR) with 10% of vermicompost tea, then the treatment of mycorrhizae with phosphate Rock plus half the fertilizer recommendation (MR) with 10% of vermicompost tea, then the treatment of mycorrhizae with azotobacter plus half of the fertilizer recommendation (MA) with 10% of vermicombe tea. Then the two treatments of mycorrhizae (M) and azotobacter (A) separately, while finally came the treatment of chemical fertilization (S), which gave the lowest values to the mentioned properties in the soil and plants.

Solubilization and Uptake of Phosphorus (P) by Wheat and Maize Crops from Indigenous Rock Phosphate Applied with Biogas Slurry and Bagasse Ash

Solubilization and Uptake of Phosphorus (P) by Wheat and Maize Crops from Indigenous Rock Phosphate Applied with Biogas Slurry and Bagasse Ash

Preparation and characterization of bioceramic composites based on anorthite and β-TCP from dolomitic phosphate and kaolin rocks

The current study demonstrates the possibility of producing novel economic biomaterials with biocompatible and acceptable mechanical properties for bone tissue engineering applications from dolomitic phosphate and kaolin rocks. The solid-state reaction was adapted to produce various batch compositions, through the substitution of kaolin with dolomitic phosphate rocks in which 20–30 wt% dolomitic phosphate rock was combined with kaolin material (20 PK, 25 PK and 30 PK). The fabricated ceramics composites were sintered at different temperatures ranging from 1175 to 1325 ᴼC. The phase composition, bulk density and bending strength of the sintered bioceramics were evaluated through X-ray diffraction (XRD), applying the Archimedes method, and 3-point bending test, respectively. Moreover, the in-vitro tests were estimated by immersing the samples in stimulated body fluid solution (SBF). The results showed that anorthite, β-tricalcium phosphate, and calcium magnesium phosphate were produced as primary phases during the sintering process and that their content increased with the increase in the phosphate rock content. Notably, the sample containing 20 wt% dolomitic phosphates exhibited good densification of 1.99 g/cm3 and achieved a bending strength of 45.66 MPa at 1250 °C. After immersing in the SBF for four weeks, changes in the surfaces of all the studied materials were observed, owing to the deposition of apatite particles. The pH values were in a nearby region of the natural pH levels. Such behaviour may be related to the sample's high stability, which originated from its chemical composition and dense structure. Moreover, a cytotoxicity test was carried out using osteosarcoma cells (HOS). The results demonstrated that all the studied bioceramics composites are safe for use as potential biomaterials.

Effects of rock phosphate and PK mineral fertilizer on soil fertility and cocoa production in south-central Côte d'Ivoire

Côte d'Ivoire is the world's leading cocoa producer, but sustainable cocoa production is threatened by, among other things, the country's dwindling forest reserves and declining soil nutrients, mainly phosphorus. To remedy the decline in soil fertility, a study of a mineral amendment was carried out in south-central Côte d'Ivoire to ensure the sustainability of cocoa production. Specifically, the aim was to evaluate the effects of rock phosphate (RP) and PK mineral fertilizer on soil fertility and cocoa production at Divo, over three years of trials. The experimental set-up was a Fisher block design, with 4 replications for 5 treatments. The results showed that, in terms of soil fertility, treatments receiving rock phosphate generally had good assimilable phosphorus content (≥ 11.5 Cmolkg-1), a Ca/Mg ratio of between 1 and 1.5, Mg/K≥3, (Ca+Mg)/K of between 12 and 40 and Ca/SBE x100 ≥ 68%. These ratios reflect not only good cocoa-growing soil, but also a good balance between Ca and the sum of exchangeable bases (SBE) and between K and the sum of Ca and Mg. On the other hand, all treatments had potassium deficiencies with (K/S) x100 < 8%. As for yield, treatments T1 (100%RP + 100% NPK 0-23-19) with 2953.44 Kgha-1, T2 (90%RP + 100% NPK 0-23-19) with 2962.95 Kgha-1 and T3 (80% RP + 100% NPK 0-23-19) with 2862.10 Kgha-1 were the most expressive.

Phosphate removal from wastewater for the manufacture of struvite fertilizer

One of the non-renewable natural resources is phosphate rock. Phosphate is currently a lot necessity, while the need for phosphate is estimated to last within 30 to 300 years. Therefore, it is necessary to strive for the development of new sustainable sources of phosphate to maintain phosphate stability. Stirring is an efficient method in the crystallization process where the stirring speed affects the growth of struvite crystals. The purpose of this study was to study the growth of struvite crystals with the struvite crystallization process with the influence of stirring rotations of 100, 150 and 200 rpm at a temperature of 30oC. The experiment was carried out by mixing the two solutions in a 1000 ml glass beaker. The reaction time and pH of struvite crystallization were evaluated in this experiment. The crystals obtained were characterized using a scanning electron microscope (SEM) with energy dispersion x-ray (EDX) and x-ray fluorescence (XRF). From the results of the study, it was found that the highest P2O5 content at a stirring speed of 100 rpm and a temperature of 30oC was 47.5%, and was included in the quality of triple superphosphate fertilizer.The morphology of the irregular flake crystals was a typical form of struvite crystals with a size of 20 m.