The Extended Effect of Top-Dressed Recovered Struvite Fertiliser on Residual Irish Grassland Soil Phosphorus Levels Compared to Commercial Phosphorus Fertiliser

Phosphorus (P) is an essential growth-limiting nutrient that cannot be synthetically produced. Mineral P fertilisers are typically applied to crops to sustain modern farming practice and food production. These fertilisers are generally derived from finite phosphate ore, for which there is much concern over long-term sustainability. To address these concerns, various technologies have been developed to recover P from municipal wastewater treatment plants. One product recovered from these processes is struvite, which is a precipitate formed of magnesium, ammonium, and phosphate. To analyse the fertilisation value of the recovered struvite, field trials were conducted on perennial ryegrass (Lolium perenne) over three growing seasons, analysing the dry matter yield of recovered struvite fertiliser. The trial was based on a three-crop silage system designed to mimic typical Irish agricultural practice. This research highlights that recovered struvite as a fertiliser provides additional benefits including increasing the soil P levels. The struvite test case produced a statistically significantly increased soil P level from the baseline of Morgan’s extractable P content of 6.4 mg/L to the optimum Morgan’s soil P level of 11.13 mg/L. The findings of this research provide insight into the added benefits of recovered struvite fertiliser as a sustainable renewable P fertiliser.

Influence of phosphorus fertilizers of various composition on the yield of tomato crops and control of their consumption by plants

Phosphate fertilizers are widely used for growing crops. To obtain phosphoric fertilizers, phosphoric acid purified using organic solvents, one of which is 100% tributyl phosphate, is used. The authors of the paper have chosen this solvent to obtain purified phosphoric acid. Purification from impurities included the stages of extraction and reextraction. On the basis of the re-extract and chemically pure phosphoric acid, a phosphoric fertilizer magnesium-ammonium phosphate (MgNH4PO4) was synthesized and used in the greenhouse experiment. The greenhouse experiment consisted in growing a tomato crop included three options for fertilization. A comparative analysis of the stimulating effect of magnesium-ammonium phosphate, synthesized with the use of phosphoric acid of varying degrees of purification, on the yield of tomato culture has been carried out.The paper proposes a blister-colorimetric version of the determination of phosphate ions in a blister cell containing a mixture of dry reagents in the form of a bulk. The optimal conditions for carrying out colorimetry have been selected. The proposed method makes it possible to semi-quantitatively determine phosphorus in various objects without preparing reagent solutions, using a bulk packed in an ampoule or blister, and can be used to control phosphorus consumption by plants, which, in turn, allows regulating the introduction of nutrients in the form of dressings.

Experimental studies of ignition of ammonium nitrate in interaction with magnesium and sulfur powders

Выполнены экспериментальные исследования взрывоопасности взаимореагирующих веществ: нитрата аммония (аммиачной селитры), который является сильным окислителем, относится к пожароопасным соединениям, в смеси с магнием и серой. Исследования свидетельствуют о взрывоопасности металлов и серы при их взаимодействии с пожароопасным веществом - окислителем (нитратом аммония). Эти особенности аммиачной селитры должны учитываться в процессе ее обращения (производство, хранение, транспортирование, применение, утилизация), при предотвращении и тушении пожаров. Ammonium nitrate (ammonia nitrate) is widely used in industry and in agriculture. The use of ammonium nitrate as a fertilizer gives this strong oxidizer a reputation of harmless agricultural chemical. At the same time, many cases of fires and explosions were registered during the storage, transportation and processing of saltpeter. Saltpeter decomposes with the release of highly toxic nitrogen oxides, which actively maintain combustion, and in case of fire also with release of oxygen. The analysis of statistical data on fires and explosions during the circulation of ammonium nitrate indicates serious problems in ensuring fire and explosion safety of buildings and structures in particular facilities of its storage. Clean and dry saltpeter explodes at normal temperature only in the presence of large volumes of the substance under the influence of a strong initiator, for example, a detonator. However, in the presence of some substances of both organic and inorganic origin the decomposition temperature of saltpeter decreases and this process of chemical spontaneous combustion can lead to an explosion. There are conducted experimental investigations by the method of constant volume bomb to determine the excess explosion pressure (ΔР) at interaction of ammonium nitrate with magnesium and sulfur powders and to compare these data with the calculated data of the excess explosion pressure (ΔР). It is established that the explosion pressure increases continuously with an increase in the concentration of the oxidant for mutually reactive substances consisting of combustible chemical element (magnesium, sulfur) and ammonium nitrate. This feature of the explosion of metals with an oxidizer - ammonium nitrate is a consequence of metal oxidation as well as the direct influence of decomposition products of the oxidizer in explosion. The growth of the overpressure of the explosion is also determined in the experiments when changing the volume of the reaction vessel (bomb camera) At the same specific weight of the mixture of mutually reactive substances (magnesium - ammonium nitrate) the explosion pressure increases with the volume of the bomb (the camera). The performed studies show that the contact of ammonium nitrate (ammonia nitrate) with foreign inclusions (additives) and, in particular, with metals and sulfur can lead to an explosion.

Pembentukan Pupuk Struvite dari Limbah Cair Industri Tempe dengan Proses Aerasi

ABSTRACT Struvite, also known as magnesium ammonium phosphate hexahydrate, is a white crystal with a chemical formula magnesium ammonium phosphate hexahydrate (MgNH4PO4.6H2O). Because of its phosphate content, struvite can be utilized as a fertilizer. Tempeh industrial effluent contains a high concentration of PO4, making it a possible struvite fertilizer producing material. The formation of struvite fertilizer is carried out by the aeration process. This process is able to increase the pH and homogeneity of the solution. The solution of Magnesium Ammonium Phosphate (MAP) is prepared by reacting tempeh industrial wasterwater, Magnesium Chloride (MgCl2), and Ammonium Hydroxide (NH4OH). The MAP ratios used are 1:1:1 and 3:1:1. The temperature was set at 30 °C and pH 9, the airflow rate was carried out at a rate of 0.25 - 1.25 liters per minute. Struvite crystals were analyzed using X-ray Fluorescence (XRF) and Scanning Electron Microscope (SEM). The best struvite fertilizer content is magnesium by 40.3% and phosphorus by 43.9% at an air flow rate of 1.25 liters per minute and a ratio of 3:1:1. Further development can be done by applying struvite fertilizers to plants. Keywords: aeration, crystallization, tempeh industrial wastewater, struvite ABSTRAK Struvite adalah kristal putih yang secara kimiawi dikenal sebagai magnesium amonium fosfat heksahidrat (MgNH4PO4.6H2O). Struvite dapat dimanfaatkan menjadi pupuk karena kandungan fosfat (PO4) di dalamnya. Limbah cair industri tempe memiliki kandungan PO4 yang cukup tinggi, menjadikan limbah cair industri tempe adalah bahan pembentuk pupuk struvite yang potensial. Pembentukan pupuk struvite dilakukan dengan proses aerasi. Proses ini mampu meningkatkan pH dan homogenitas dari larutan. Larutan MAP (Magnesium Amonium Fosfat) dibuat dengan cara mereaksikan limbah cair industri tempe, Magnesium Klorida (MgCl2), dan Amonium Hidroksida (NH4OH). Rasio MAP yang digunakan adalah 1:1:1 dan 3:1:1. Temperatur ditetapkan sebesar 30°C dan pH 9, laju alir udara dilakukan dengan laju 0,25 - 1,25 liter per menit. Kristal struvite dianalisis menggunakan Floresensi sinar-X (XRF) dan Mikroskop Pemindai Elektron (SEM). Kandungan pupuk struvite terbaik adalah magnesium sebesar 40,3% dan fosfor sebesar 43,9% pada konsentrasi 3:1:1 dan laju alir udara 1,25 liter per menit. Pengembangan lebih lanjut dapat dilakukan dengan mengaplikasikan pupuk struvite ke tanaman. Kata Kunci: aerasi, kristalisasi, limbah cair industri tempe, struvite

Enterolithiasis in a 15 Year Old Dongola Breed Stallion

Equine enteroliths are mineral accumulations of magnesium-ammonium-phosphate (struvite) around a foreign object that form round, triangular, or flat stones inside the bowel usually over the course of multiple years. They form in the large colon of horses where they can remain for some time until they move and cause an obstruction in the large or small colon, resulting in colic. A 15year old Dongola stallion was presented with a bout of colic, history revealed that the horse repeatedly had been having recurrent bouts of colic. The animal was not responding to treatment rather it was getting worse. The horse died before surgical intervention could be carried out. At post mortem twenty enteroliths were discovered in the colon.