Bernardcolon0565

The feasibility of use microalgae biotechnology to improve water quality together with the production of biomass to replace fish meal or fish oil in two marine fish farms with different production systems were studied. The samples were taken from a flow-through system (FTS) and a recirculating aquaculture system (RAS) with sea bass cultures of 300 g and 120 g, respectively. The most suitable stream for microalgae cultivation was that from RAS as the concentration of N in the microalgae reactor influent should be ≥8 mg TN L-1 to operate at the same hydraulic retention time than the solids retention time, independently of the productivity of the reactor. Tetraselmis chuii were cultured in 18 L bubble column reactors under batch and semi-continuous operation in media that mimic a RAS stream. The results showed that RAS systems enriched with trace metals generate viable streams for microalgae growth with average biomass productivity under semi-continuous operation of 69 mg TSS L-1 d-1. Nutrients concentrations at the end of the experiment under semi-continuous operation were 0.76 mg TDN L-1 and 0.01 mg TDP L-1, similar to those in the make-up water of the RAS. The composition of microalgae biomass obtained shows that it could be optimal as a substitute for fish meal in sea bass feed.Biofouling caused by the growth of the biofilm is the main bottleneck that limits the effective operation of thin-film composite (TFC) membrane in the forward osmosis (FO) process. This study investigated the combined effects of graphene oxide (GO) immobilized thin-film nanocomposite (TFN-S) membrane and Pseudomonas quinolone signal (PQS)-based quorum quenching on biofouling mitigation, especially under the operation of pressure-retarded osmosis (PRO) mode, and the influence of methyl anthranilate (MA) inhibitor on the composition and structure of biofilm was also evaluated. Synthetic wastewater was used as the feed solution, in which the model strain Pseudomonas aeruginosa was added to simulate biofouling. The results showed that GO modification and MA addition both efficiently mitigated flux decline and EPS secretion, but the interference of PQS pathway on biofouling control was better than GO embedding. TFN-S membrane with MA addition exhibited superior anti-biofouling performance based on the combined effects of GO and MA. The alleviated concentration polarization and enhanced hydrophilicity of the TFN-S membrane reduced the flux decline in the early stage. Additionally, the antibacterial property of GO inhibited the viability of the attached bacteria (under PRO mode) and MA further mitigated the EPS secretion and biofilm development in the later stage. In the presence of PQS inhibitor MA, live/total cells ratio was 15% and 13% higher than that of TFC membrane in FO and PRO modes, respectively. Furthermore, exogenous addition of MA led to a relatively loose biofilm structure, resulting in high membrane permeability in the biofouling formation process.Urine and fecal excretions from cattle contribute to global nitrogen (N) emissions. The milk urea nitrogen (MUN) concentration in dairy cows is positively correlated with urinary urea N (UUN) emissions, and both decline with the reduction in crude protein intake. However, MUN concentration may differ between individual cows despite feeding the same ration. Thus, we hypothesized that due to differences in endogenous N utilization cows with high MUN concentration excrete more UUN than cows with a low MUN concentration. The objective of the present study was to elucidate N partitioning and urea metabolism in dairy cows with divergent MUN concentrations fed two planes of crude protein. Twenty Holstein dairy cows with high (HMU; n = 10) and low (LMU; n = 10) milk urea concentrations were fed two isocaloric diets with a low (LP) and normal (NP) crude protein level. Methane and ammonia emissions were recorded in respiration chambers. Feed intake, feces and urine excretions and milk yield were recorded for four days and subsamples were analyzed for total N and N-metabolites. A carbon-13 labeled urea bolus was administered intravenously followed by a series of plasma samplings. Total N and UUN excretions and ammonia emissions from excreta were lower on the LP diet, however, methane emissions, urinary N excretions and ammonia emissions were comparable between groups. Although plasma and salivary urea concentrations, urea pool size and urea turnover were higher, HMU cows had lower renal urea clearance rates. Additionally, HMU cows had lower renal clearance rates for creatinine, uric acid and creatine and excreted less uric acid (on the LP diet only) and creatine with urine. In conclusion, contrary to our hypothesis, HMU cows did not excrete more UUN than LMU cows. The lower urinary creatine excretion of HMU cows suggests that these animals have a lower environmental nitrogen footprint.Peroxymonosulfate (PMS) non-radical reactions possess high catalytic activity for specific pollutants under complex water environments. However, the synthesis of high-performance catalysts and the discussion of non-radical reaction mechanisms are still unsatisfactory. Selleckchem BMN 673 Here, a novel and efficient non-radical catalyst (O-CuCN) was successfully assembled using the scheme of Copper (Cu) and oxygen (O) co-doping. The O element with great electronegativity induces graphite carbon nitride (g-C3N4) to act as a medium to change the phase properties and electron density distribution of g-C3N4, and provides a support for the targeting of Cu. Cu is introduced into g-C3N4 as an active site in the phase structure, and an electron-rich center with the Cu site is formed, which forms a metastable intermediate after the adsorption of PMS by Cu as the active site. The new catalyst O-CuCN has outstanding activity in the PMS system, and its degradation rate for bisphenol A (BPA) is increased by more than 20 times compared to that of g-C3N4, and it has excellent environmental tolerance and stability. This work demonstrates that the formation of metastable intermediates and the initiation of effective non-radical reactions can be achieved by constructing differentiated electron density structures.