tetracycline and 4-chlorophenol

A porous carbon aerogel (CA) was prepared to activate persulfate (PS) for the removal of phenol. The adsorption of phenol on CA and its removal in CA/PS system was fitted to a second-order model and first-order kinetic model, respectively. Influencing factors of CA/PS such as pH, CA dose, PS concentration, phenol concentration and temperature were investigated. CA/PS presented good performance on phenol removal over a pH range of 3-11 with the highest removal obtained at pH 7. Four kinds of organic pollutants including tetracycline, Rhodamine B, Safranine T and malachite green were investigated in the CA/PS system, proving that the adsorption of the contaminants benefitted their subsequent oxidation removal. The removal of aromatic compounds (phenol, p-diphenol, p-chlorophenol, and p-nitrophenol) in CA/PS system followed a decreasing order of hydroxyl > chlorine > nitro. The radical scavenging experiments suggested the removal of phenol was mainly through a non-radical pathway. The study presented the preparation and application of a green catalyst to activate PS, which is very promising for the development of the technology and the treatment of phenolic wastewater.

Topics: Adsorption; Carbon; Catalysis; Chlorophenols; Hydroxyl Radical; Kinetics; Nitrophenols; Oxidation-Reduction; Phenol; Porosity; Sulfates; Tetracycline; Wastewater; Water Pollutants, Chemical

Considering the occurrence and spread of antibiotic resistance genes (ARGs) pose significant risks to public health, the effects of long-term exposure to alkaline conditions on the relative abundances of tetracycline resistance genes (TRGs) were studied in saline 4-chlorophenol (4-CP) wastewater treatment. Alkaline conditions were maintained by supplying the co-metabolic carbon source of sodium acetate. Results showed that except for the 4-CP, the removal of pollutants was significantly inhibited, and the relative abundances of the most TRGs were repressed. In addition, the removal of pollutants and the relative abundances of TRGs were moderately affected by the NaCl addition. The proteins in the extracellular polymeric substances (EPS) played key roles in reducing the relative abundances of TRGs, which were altered by the microbial diversity. In conclusion, for the pollutants removal and ARGs reduction in refractory industrial wastewater treatment, alkaline conditions should be maintained by selecting suitable co-metabolic carbon sources.

Topics: Anti-Bacterial Agents; Chlorophenols; Genes, Bacterial; Tetracycline; Tetracycline Resistance; Wastewater

The occurrence and spread of antibiotic resistance genes (ARGs) are concerns that have threatened public health for many years. However, the effects of humic acid (HA) application on the expression of ARGs in chlorophenols wastewater treatment are rarely reported. In this study, we investigated the sludge performance, including the removal of pollutants, changes in the microbial communities, and the expression of tetracycline resistance genes (TRGs), to explore the function of HA in 4-chlorophenol (4-CP) wastewater treatment at different HA concentrations. The results showed that HA application did not significantly stimulate the removal of pollutants, other than the removal of PO

Topics: Anti-Bacterial Agents; Chlorophenols; Genes, Bacterial; Humic Substances; Microbiota; Tetracycline; Tetracycline Resistance; Wastewater

To assess the genotoxicity of 14 chemical agents used as locally applied agents in dental practice, the ability of these agents to elicit chromosome aberrations was examined using Syrian hamster embryo (SHE) cells. Chromosome aberrations in SHE cells were induced by treatment with three of eight chemical agents used as endodontic medicaments, i.e. ethylenediaminetetraacetic acid (EDTA), formocresol (a mixture of formalin and tricresol), and sodium arsenite. The other five chemical agents, i.e. chloramphenicol, p-chlorophenol, p-phenolsulfonic acid, sodium hypochlorite, and tetracycline hydrochloride exhibited a negative response for chromosome aberrations. Assessment of three dyes used for disclosing dental plaque showed chromosome aberrations induced by basic fuchsin but not by acid fuchsin and erythrosine B. Three local anesthetics, lidocaine hydrochloride, prilocaine hydrochloride, and procaine hydrochloride, were negative for chromosome aberrations. Among the ten chemical agents that exhibited a negative response in the assay, p-chlorophenol, sodium hypochlorite, and erythrosine B induced chromosome aberrations in SHE cells when treated in the presence of exogenous metabolic activation. The percentages of cells with polyploidy or endoreduplication were enhanced by formocresol, sodium arsenite, p-chlorophenol, p-phenolsulfonic acid, sodium hypochlorite, erythrosine B, prilocaine hydrochloride, and procaine hydrochloride in the absence or presence of exogenous metabolic activation. Our results indicate that the chemical agents that had a positive response in the present study are potentially genotoxic to mammalian cells.

Topics: Anesthetics; Animals; Arsenites; Benzenesulfonates; Chloramphenicol; Chlorophenols; Chromosome Aberrations; Colony-Forming Units Assay; Cricetinae; Dental Disinfectants; Dental Materials; Edetic Acid; Embryo, Mammalian; Formocresols; Gene Duplication; Mesocricetus; Mutagens; Polyploidy; Root Canal Irrigants; Sodium Compounds; Sodium Hypochlorite; Tetracycline

The efficacy of Ledermix paste in disinfection of dentinal tubules was studied in a model developed by Haapasalo and Orstavik with some modifications. Ledermix and 3% Tetracycline in a hydrous base were effective in reducing the amount of Staphylococcus aureus in dentinal tubules after 7 days of incubation and also after recontamination. They were not effective after 24 h.

Topics: Animals; Cattle; Chlorophenols; Demeclocycline; Dentin; Drug Combinations; Root Canal Irrigants; Staphylococcus aureus; Tetracycline; Triamcinolone Acetonide