Separation and Preconcentration of Boron with a Glucamine Modified Novel Magnetic Sorbent

A novel, simple method based on magnetic separation was developed for analytical purposes. In this method, N‐methyl‐D‐glucamine (NMDG) modified magnetic microparticles that were synthesized by using the sol‐gel method were used for the selective extraction and preconcentration of boron from aqueous solutions. This method combines the simplicity and selectivity of solvent extraction with the easy separation of magnetic microparticles from a solution with a magnet without any preliminary filtration step. The structure of the prepared γ‐Fe₂O₃‐SiO₂‐NMDG (magnetic sorbent) composites were characterized by using X‐ray diffraction (XRD), Transmission Electron Microscopy (TEM), and Fourier Transform Infrared Spectroscopy (FTIR). The influence of different parameters on the sorbent capacity, such as the sorption/desorption of boron, magnetic sorbent dosage, pH, equilibrium time, type, and amount of stripping solution, were evaluated by using the magnetic sorbent. Any equilibrium pH greater than 6 can be used for sorption. Desorption from the sorbent was carried out by using 1.0 M HCl. The sorption and desorption efficiency of the γ‐Fe₂O₃‐SiO₂‐NMDG was found as 92.5 ± 0.5% and 99.8 ± 6%, respectively.     

Recovery of Plant Nutrients from Dilute Solutions of Human Urine and Preliminary Investigations on Pot Trials

Within the context of Ecological Sanitation (ECOSAN), human urine has been the subject of research and practice as a potential fertilizer in the recent years. Although quite a lot had been done with original undiluted urine with promising outcomes, not much appears in the literature which concentrates on dilute solutions of urine. This is important because unless waterless toilets are employed, urine will be diluted with flush water in actual use. In this work, dilute solutions of urine are investigated with emphasis on the recovery of plant nutrients. A natural zeolite namely clinoptilolite was loaded with nitrogen, phosphorus, and potassium as an indirect route of processing urine. The results have revealed that hydrolysis is completed in shorter times in dilute samples. Clinoptilolite could successfully remove plant nutrients from all dilute solutions. Nitrogen could be recovered up to 86% with higher efficiencies at higher concentrations in general. Recovery of orthophosphates increases with increasing concentration to reach 96%, however, potassium could not be recovered. The preliminary experiments with grass have revealed that nutrient loaded clinoptilolite was as effective as chemical fertilizers while direct application of original and diluted solutions of urine had shown inferior yields.