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Instruments / Technical Area	Publication Details	Published
B18-Core EXAFS I18-Microfocus Spectroscopy	Abiotic reduction of Cr(VI) by humic acids derived from peat and lignite: kinetics and removal mechanism Suha T. Aldmour , Ian T. Burke , Andrew W. Bray , Daniel L. Baker , Andrew B. Ross , Fiona L. Gill , Giannantonio Cibin , Michael E. Ries , Douglas I. Stewart Environmental Science And Pollution Research 29 DOI: 10.1007/s11356-018-3902-1 Diamond Proposal Number(s): [12696, 15711] Open Access Show Abstract ▼ Abstract: Hexavalent chromium contamination of groundwater is a worldwide problem caused by anthropogenic and natural processes. We report the rate of Cr(VI) removal by two humic acids (extracted from Miocene age lignite and younger peat soil) in aqueous suspensions across a pH range likely to be encountered in terrestrial environments. Cr(VI) was reduced to Cr(III) in a first-order reaction with respect Cr(VI) concentration, but exhibited a partial order (~ 0.5) with respect to [H+]. This reaction was more rapid with the peat humic acid, where Cr(VI) reduction was observed at all pH values investigated (3.7 ≤ pH ≤ 10.5). 13C NMR and pyrolysis GC-MS spectroscopy indicate that the reaction results in loss of substituted phenolic moieties and hydroxyl groups from the humic acids. X-ray absorption spectroscopy indicated that at all pH values the resulting Cr(III) was associated with the partially degraded humic acid in an inner-sphere adsorption complex. The reaction mechanism is likely to be controlled by ester formation between Cr(VI) and phenolic/hydroxyl moieties, as this initial step is rapid in acidic systems but far less favourable in alkaline conditions. Our findings highlight the potential of humic acid to reduce and remove Cr(VI) from solution in a range of environmental conditions.	Dec 2018
I22-Small angle scattering & Diffraction	Optimal design of crystallization processes for the recovery of a slow nucleating sugar with a complex chemical equilibrium in aqueous solution: the case of lactose Elena Simone , Arwen I. I. Tyler , Daniel Kuah , Xiaofan Bao , Michael Ries , Daniel Baker Organic Process Research & Development DOI: 10.1021/acs.oprd.8b00323 Diamond Proposal Number(s): [16566] Show Abstract ▼ Abstract: Lactose is the major carbohydrate in milk and, similarly to other sugars, it can exist as two anomers in solution, the α and β forms, with a ratio depending on factors including temperature and pH (mutarotation equilibrium). Lactose is extracted from whey mostly to prevent environmental pollution. In fact, the presence of this sugar can contribute to a dramatic increase in the biological oxygen demand (BOD) of whey, making its direct disposal potentially dangerous for the environment. However, preserving our ecosystem is not the only reason why lactose is recovered. Purified lactose is, in fact, a high value product, commonly used as an excipient in pharmaceutical formulations and as a carrier in dry powder inhalers. Despite the increasing interest that lactose crystallization has recently received, a full understanding of this process is still missing, particularly the link between the process parameters of the crystallization step and the properties of the final product in terms of crystalline structure, purity and particle size and shape distribution. This work is the first comprehensive study of lactose crystallization, exploring cooling and anti-solvent operations, for the determination of the effect of several operative conditions on: (i) the kinetics of nucleation, growth and agglomeration; (ii) the yield of lactose recovery from solution; (iii) the final crystal size and shape distributions; and (iv) the purity of the obtained crystals.	Jan 2019
DL-SAXS-Offline SAXS and Sample Environment Development	Polymorphism of a highly asymmetrical triacylglycerol in milk fat: 1-butyryl 2-stearoyl 3-palmitoyl-glycerol Yoga Pratama , Sam Burholt , Daniel L. Baker , Amin Sadeghpour , Elena Simone , Michael Rappolt Crystal Growth & Design 43 DOI: 10.1021/acs.cgd.2c00713 Diamond Proposal Number(s): [29590] Show Abstract ▼ Abstract: Milk fat has more than 200 triacylglycerols (TAGs), which play a pivotal role in its crystallization behavior. Asymmetrical TAGs containing short butyryl chains contribute to a significant portion of milk fat TAGs. This work aims to elucidate the crystallization behavior of asymmetrical milk fat TAGs by employing the pure compound of 1-butyryl 2-stearoyl 3-palmitoyl-glycerol (BuSP). The structural evolution of BuSP after being cooled down to 20 °C from the melt is evaluated by small- and wide-angle X-ray scattering (SAXS and WAXS) and differential scanning calorimetry (DSC). The temporal structural observation shows that BuSP crystallizes into the α-form with short and long spacings of 4.10 and 56.9 Å, respectively, during the first hour of isothermal hold at 20 °C. The polymorphic transformation of the α to β′ phase occurred after 4 h of isothermal hold, and the β′- to α-form fraction ratio was about 70:30 at the end of the isothermal experiment (18 h). Pure β′-form X-ray patterns are obtained from the BuSP powder with short spacings of 4.33, 4.14, and 3.80 Å, while the long spacing of 51.2 Å depicts a three-chain-length lamellar structure with a tilt angle of 32°. Corresponding DSC measurements display that BuSP crystallizes from the melt at 29.1 °C, whereas the melting of α- and β′-forms was recorded at 30.3 and 47.8 °C, respectively. In the absence of the β-form, the β′-polymorph is the most stable observed form in BuSP. This work exemplarily explains the crystallization behavior of asymmetrical milk fat TAGs and thus provides new insights into their role in overall milk fat crystallization.	Sep 2022

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