Phosphorus and Ammonium Ions Removal by Using the Microalgae Dunaliella Salina

Biological treatment for industrial effluent was performed in laboratory scale experiment by using marine microalgae Dunaliella salina. The dark colored wastewater, containing high level of organic matter and low pH which may prevent microalgae growth. The research showed that within 5 days of incubation in the wastewater, D. salina grew from 3×106 to 1.5×107 cell/mL. D. salina reduced approximately phosphorus (29%), and ammonium ionic (68%). The research demonstrated the possibility of using marine microalgae for bioremediation treatment of industrial wastewater, specifically

Membrane/electrolyte interplay on ammonia motion inside a flow-cell for electrochemical nitrogen and nitrate reduction

Electrochemical ammonia production from molecular nitrogen and nitrate reduction reactions at ambient conditions has gained a lot of attention in recent years, making this topic more and more appealing. The race towards good and quick results in terms of Faradaic efficiency and productivity is not always focused on the possible source of ammonia contamination. In particular, Nafion membrane is the most commonly used in this field as cell separator, discarding the possible known disadvantages coming from ammonium ions absorption and release. The wettable microporous Celgard membrane has been proposed as a substitute for Nafion membranes, despite the separation mechanism, in this case, is only dimension-driven, so it does not assure ammonium ions retention. This paper reveals that the mechanism of ammonium ions absorption and release by Nafion 117 is strongly related to the cations present in the electrolyte and to a lesser extent by its pH value. On the other hand, Celgard membrane does not show any relevant ammonium ions absorption. Moreover, the different trend of ammonium ions motion from catholyte to anolyte solution inside a flow-cell reactor shows that none of the membranes is able to avoid ammonium ions crossover and that there is a correlation between the applied potential and the motion trend. Electrochemical nitrogen and nitrate reduction tests confirm how Nafion membrane can have a big impact on the final result of ammonium ions production, especially when dealing with low production quantities, leading to mistakes in the real quantity of ammonium ions coming from the reduction reaction

Synthesis and recognition properties of α-d-glucose-based fluorescent crown ethers incorporating an acridine unit

Two new chiral glucopyranoside-based crown ethers incorporating acridine fluorescent signalling units, 15-membered ligand 1 and 21-membered ligand 2 were synthesized. Their complexation properties toward alkali and alkali earth metal ions, and their enantioselectivity towards chiral ammonium salts were studied by absorption and fluorescence spectroscopic experiments. Macrocycle 1 formed 1:1 complexes with all the metal ions selected and the stability constants were low (lg K < 2.3). The cavity-size of 2 allowed only the complexaton of organic ammonium ions. Crown 2 showed chiral discrimination in case of all the four ammonium salts used as model guest compounds; the highest enantioselectivity (K(R)/K(S) ~3) was observed for the enantiomers of phenylethyl ammonium perchlorate. Ligand 2 forms much more stable complexes with metal ions; the highest stability constant was obtained for the Ca2+ complex (lg K = 6.15). The coordination of metal ions by ligand 2 was accompanied by marked fluorescence enhancement, whereas the binding of ammonium ions by the same species resulted in significant fluorescence quenching. © 2014 Springer Science+Business Media Dordrecht

A Quasi-Elastic Neutron Scattering Study of the Ammonium Ions in CsNH4-Y Zeolite

Quasi-elastic neutron scattering was used to study the reorientation mechanism for ammonium ions in Cs-exchanged zeolite Y. This sample contains ammonium ions preferentially located in the sodalite cages at site 1'. These ions reorient with 120 or 180 Deg jumps around fixed axes through the N atom. This corresponds to a bonding geometry in which the ammonium ion interacts via 3 or 2 H atoms with the lattice O atoms. Addnl., a reorientation around a fixed axis through 2 H atoms of the ammonium ion may occur. The ammonium ion then jumps between 2 equil. positions: one position involves a 2-fold bonding geometry and the other a 3-fold bonding geometry. At 300 K the effective time interval between 2 jumps is t = 1.2 +- 0.5 ps. Compared to zeolite Rho, the ammonium ions in the Cs-exchanged zeolite Y show a more restricted reorientational behavior, resulting in a larger elastic incoherent structure factor. [on SciFinder (R)

Simultaneous ammonium and phosphate recovery and stabilization from urban sewage sludge anaerobic digestates using reactive sorbents

The use of low-cost inorganic sorbents as a new sustainable strategy to enhance the valorization of nutrients (N-P-K), from the urban water cycle (e.g., side streams from sewage sludge anaerobic digestion), in agriculture applications is presented. The simultaneous recovery and stabilization of ammonium and phosphate by using a mixture of two reactive sorbents (Na and K zeolites and magnesium oxide) was evaluated. The nutrients stabilization process, favoured at alkaline pH values, is carried out by a) the precipitation of phosphate ions with magnesium and/or ammonium ions and b) the sorption of ammonium by Na- and K-zeolites. MgO(s) promoted the stabilization of phosphate as bobierrite (Mg3(PO4)2(s)) or struvite (MgNH4PO4(s)) depending on the applied dose. Doses with the stoichiometric molar ratio of Mg/P promote the formation of bobierrite, while molar ratios higher than 3 favour the formation of struvite. Na zeolites (NaP1-NA, NaP1-IQE) demonstrated efficiency on ammonium stabilization between 60 ± 2 (for 15 gZ/L) to 90 ± 3% (for 50 gZ/L). The ammonium recovery efficiency is limited by the zeolite sorption capacity. If the target of the fertilizing criteria should include K, then the use of a K-zeolite (e.g., 5AH-IQE) provides a good solution. The optimum pH for the precipitation of struvite and bobierrite is 9.5 and the optimum pH for ammonium removal is between 4 and 8.5. N is present in higher concentrations (up 0.7–1 g NH4+/L) when pH is ranged between 8.2 and 8.6. The ammonium recovery ratios were better than those previously reported using only magnesium oxide or even a more expensive reagent as newberrite (MgHPO4(s)). The recovery mechanisms described generate low-solubility stabilized nutrients forms that potentially can be applied as slow-release fertilizers in agriculture. Thus, the use in agriculture of blends of digested sludge with low-solubility stabilized nutrients forms will improve soils quality properties in terms of organic matter and nutrients availability.Peer ReviewedPostprint (author's final draft

Removal of ammonium Ions from digested sludge fugate by using natural zeolite

Wastewater treatment loadings with total nitrogen can increased by introducing fugate that is saturated with ammonium ions, generated when dewatering wastewater treatment sludge. In this article the possibility to reduce the concentration of ammonium ions in the fugate by the use of natural zeolite (Transcarpatian clinoptilolite) has been analysed. Lab-scale experiments were carried out with different particle sizes zeolite: 0.8–1.6 mm, 1.6–2.5 mm and 2.5–3.2 mm. At the first stage of the experiments, zeolite particles were mixed with fugate and left to settle until a 99% efficiency of ammonium ion removal was achieved. At the second stage, ammonium ions were removed from the fugate by filtering this liquid through zeolite where the 70–92% efficiency was achieved. Zeolite saturated with ammonium ions possibly can be used in agriculture as nitrogenous fertilizers. Obtained fertilizer grade of zeolite saturated with fugate can also be produced from the high ammonium nitrogen concentration side-streams separated from wastewater flow from sludge digestion processes. First published online: 18 May 201

Method for processing of titanomagnetite ore of Kolvitskoy deposit

The research results of hydrometallurgical processing of titanomagnetite ore of the Kolvitsky deposit of Kola region have been presented. The method is based on selective extraction of titanium from ore by solution, which contains ammonium and fluorine ions. The most promising results were obtained utilizing solution with fluorine ions concentration of 0,95 mol/L and ammonium ions concentration of 0,5 mol/L. Under these conditions the Fe/Ti ratio in ferreous concentrate was increased 3 times in comparison with original ore. Concentration of fluorine ions in ammonium fluoride solution affects selectivity of titanomagnetite ores processing and shows principal possibility to control process using this parameter

Method for processing of titanomagnetite ore of Kolvitskoy deposit

The research results of hydrometallurgical processing of titanomagnetite ore of the Kolvitsky deposit of Kola region have been presented. The method is based on selective extraction of titanium from ore by solution, which contains ammonium and fluorine ions. The most promising results were obtained utilizing solution with fluorine ions concentration of 0,95 mol/L and ammonium ions concentration of 0,5 mol/L. Under these conditions the Fe/Ti ratio in ferreous concentrate was increased 3 times in comparison with original ore. Concentration of fluorine ions in ammonium fluoride solution affects selectivity of titanomagnetite ores processing and shows principal possibility to control process using this parameter

Ammonium ion recognition: luminescent amino acid and peptide receptors. Modification of amino acids: artificial amino acids, cyclopeptides and guanidinium-bis-carboxylates

Different concepts for recognition of organic ammonium ions in solution are discussed. In the practical part of the thesis di- and tritopic artificial receptors for ammonium ions, amino acids, neurotransmitters and different biological important peptides bearing ammonium and phosphate groups are presented. The second part deals with the modification of amino acids leading to artificial amino acids, guanidinium-bis-carboxylates and cyclopeptides