Genome Sequences of Microbacterium foliorum Phages Anseraureola, Pondwater, and Yasuo.

Anseraureola, Pondwater, and Yasuo are bacteriophages with siphovirus morphology that infect Microbacterium foliorum NRRL B-24224. They were isolated from soil collected in Amherst, Massachusetts, and have genome lengths between 17,362 bp and 17,453 bp. These phages each contain 25 predicted protein-coding genes and are assigned to phage cluster EE.

Sonochemical degradation of organophosphorus pesticide in dilute aqueous solutions.

Ultrasonic irradiation was found to accelerate the rate of hydrolysis of omethoate in aqueous solution over the pH range of 2-12. Process parameters studied include pH, steady-state temperature, concentration, and the type of gases. Greater than 96% hydrolysis was observed in 30 minutes through this process and the rate of destruction increased with the help of more soluble and low thermal inert gas. So with Krypton, omethoate was found to undergo rapid destruction as compared with Argon. In the presence of ultrasound, the observed first-order rate of hydrolysis of omethoate is found to be independent of pH. The formation of transient supercritical water (SCW) appears to be an important factor in the acceleration of chemical reactions in the presence of ultrasound. A detailed chemical reaction mechanism for omethoate destruction in water was formulated. Experimental results and theoretical kinetic mechanism demonstrated that the most of the omethoate undergo destruction inside the cavitating holes. A very less effect of temperature on the degradation of omethoate within a temperature range of 20-70 degrees C proves that a small quantity of omethoate undergoes secondary destruction in the bulk liquid.

Toxicity formation and distribution in activated sludge during treatment of N,N-dimethylformamide (DMF) wastewater.

The organic toxicity of sludge in land applications is a critical issue; however, minimal attention has been given to the mechanism of toxicity formation during high-strength wastewater treatment. To investigate the relevant factors that contribute to sludge toxicity, synthetic wastewater with N,N-dimethylformamide (DMF) was treated in a sequential aerobic activated sludge reactor. The acute toxicity of sludge, which is characterised by the inhibition rate of luminous bacteria T3, is the focus of this study. Using an operational time of 28 days and a hydraulic retention time of 12h, the study demonstrated a positive relationship between the acute toxicity of sludge and the influent DMF concentration; the toxicity centralised in the intracellular and inner sections of extracellular polymeric substances (EPS) in sludge flocs. Due to increased concentrations of DMF, which ranged from 40 to 200mgL(-1), the sludge toxicity increased from 25 to 45%. The organic toxicity in sludge flocs was primarily contributed by the biodegradation of DMF rather than adsorption of DMF. Additional investigation revealed a significant correlation between the properties of the bacterial community and sludge toxicity.

[Effects of operating parameters on organic toxicity of sludge treating synthetic bisphenol A wastewater].

In order to investigate the influence of hydraulic retention time (HRT) and sludge retention time (SRT) on sludge organic toxicity in sequencing batch reactors (SBR(S)), the sludge toxicity was compared when HRT and SRT were controlled at various levels. The influents COD were controlled at around 300 mg x L(-1), HRT and SRT were changed from 12 h to 8 h and from 20 d to 10 d, respectively. The effluents COD, BPA contents both in liquid and sludge were measured, and sludge toxicity was also analyzed and compared between the blank group (no BPA content) and BPA control groups (40 mg x L(-1)). The results showed that the effluents COD of two SBRs were both below 50 mg x L(-1), and there were no BPA content in liquid and sludge. Furthermore, decrease HRT and SRT is helpful to remove BPA and reduce sludge toxicity. Additional investigation revealed a correlation between the properties of bacterial community and total sludge toxicity by the PCR-DGGE analysis, and different influent compositions and operation parameters were the main reasons for leading the difference of sludge toxicity.

The bromination kinetics of phenolic compounds in aqueous solution.

The purpose of this study was to investigate the bromination kinetics of selected phenolic compounds in aqueous solutions over the pH range of 5-11. The experiment results indicated that the reaction of hypobromous acid with the phenoxide ions controlled the overall reaction rate, whereas the reaction between hypobromite ion and the phenoxide ions and the reaction between hypobromous acid and the undissociated phenolic species were considered to be negligible respectively in the pH range of 7-9. The apparent second-order rate constants of the reaction of hypobromous acid with the phenoxide ions ranged from 7.9 x 10(6) M(-1) s(-1) for 3-chlorophenol to 6.5 x 10(8) M(-1) s(-1) for 3-methoxyphenol, respectively. The Hammett correlation could be successfully used to estimate the reactivity of bromine with substituted phenols and the linear regression was log(k(2))=-2.85 sigma+8.00. The rate constants of the reaction of bromine with phenol-like organic compounds were about three orders of magnitude higher than with chlorine and two to three orders of magnitude lower than with ozone.