MPAC (Alterity therapeutics)

Biogranulation has emerged as a viable alternative biological wastewater treatment approach because of its strong biodegradability potential, toxicity tolerance, and biomass retention features. However, this process requires a long duration for biogranules formation to occur. In this study, magnetic powder activated carbon (MPAC) was used as support material in a sequencing batch reactor to enhance biogranules development for wastewater treatment. Two parallel SBRs (designated R1 and R2) were used, with R1 serving as a control without the presence of MPAC while R2 was operated with MPAC. The biodegradability capacity and biomass properties of MPAC biogranules were compared with a control system. The measured diameter of biogranules for R1 and R2 after 8 weeks of maturation were 2.2 mm and 3.4 mm, respectively. The integrity coefficient of the biogranules in R2 was higher (8.3%) than that of R1 (13.4%), indicating that the addition of MPAC improved the structure of the biogranules in R2. The components of extracellular polymeric substances were also higher in R2 than in R1. Scanning electronic microscopy was able to examine the morphological structures of the biogranules which showed there were irregular formations compacted together. However, there were more cavities situated in R1 biogranules (without MPAC) when compared to R2 biogranules (with MPAC). Dye removal reached 65% and 83% in R1 and R2 in the post-development stage. This study demonstrates that the addition of MPAC could shorten and improve biogranules formation. MPAC acted as the support media for microbial growth during the biogranulation developmental process.

The composition and radiative forcing of light-absorbing brown carbon (BrC) aerosol remain poorly understood. Polycyclic aromatics (PAs) are BrC chromophores with fused benzene rings. Understanding the occurrence and significance of PAs in BrC is challenging due to a lack of standards for many PAs. In this study, we quantified polycyclic aromatic carbon (PAC), defined as the carbon of fused benzene rings, based on molecular markers (benzene polycarboxylic acids, BPCAs). Open biomass burning aerosols (OBBAs) of 22 rainforest plants were successively extracted with water and methanol for the analysis of water- and methanol-soluble PAC (WPAC and MPAC, respectively). PAC is an important fraction of water- and methanol-soluble organic carbon (WSOC and MSOC, respectively). WPAC/WSOC ranged from 0.03 to 0.18, and MPAC/MSOC was even higher (range: 0.16-0.80). The priority polycyclic aromatic hydrocarbons contributed less than 1% of MPAC. The mass absorption efficiency (MAE) of MSOC showed a strong linear correlation with MPAC/MSOC (r = 0.60-0.95, p < 0.01). The absorption Ångström exponent (AAE) of methanol-soluble BrC showed a strong linear correlation with the degree of aromatic condensation of MPAC, which was described by the average number of carboxylic groups of BPCA (r = -0.79, p < 0.01). This result suggested that PAC was a key fraction determining the light absorption properties (i.e., light absorptivity and wavelength dependence) of methanol-soluble BrC in OBBAs.