Dissolved phosphorus levels in fresh municipal wastewater.

The influence of wastewater lag-time to the concentrations of dissolved phosphorus was investigated. The dissolved phosphorus levels of fresh municipal wastewater and the rate at which phosphorus dissolves in untreated municipal water was studied. Dissolved phosphorus initially accounted for 34% of total phosphorus in the used water. The level of dissolved phosphorus in wastewater doubled during half a year of storage. The dissolving of phosphorus was most rapid in the first 10 days when dissolved phosphorus levels increased by approximately 1% per day.

Identification of hydrolysis products of AlCl(3)*6H(2)O in the presence of sulfate by electrospray ionization time-of-flight mass spectrometry and computational methods.

ElectroSpray Ionization-Mass Spectrometry (ESI-MS) and computational methods (DFT, MP2, and COSMO) were used to investigate the hydrolysis products of aluminium chloride as a function of sulfate concentration at pH 3.7. With the aid of computational chemistry, structural information was deduced from the chemical compositions observed with ESI-MS. Many novel types of hydrolysis products were noted, revealing that our present understanding of aluminium speciation is too simple. The role of counterions was found to be critical: the speciation of aluminium changed markedly as a function of sulfate concentration. Ab initio calculations were used to reveal the energetically most favoured structures of aluminium sulfate anions and cations selected from the ESI-MS results. Several interesting observations were made. Most importantly, the bonding behaviour of the sulfate group changed as the number of aqua ligands increased. The accompanying structural rearrangement of the clusters revealed the highly active role of sulfate as a ligand. The gas phase calculations were expanded to the aquatic environment using a conductor-like screening model. As expected, the bonding behaviour of the sulfate group in the minimum energy structures was distinctly different in the aquatic environment compared to the gas phase. Together, these methods open a new window for research in the solution chemistry of aluminium species.