Effects Of Natural Water Research Articles

Rice hull-derived biochar with photocatalytic activity for efficient degradation of oxytetracycline in water under sunlight

Photocatalytic degradation is an effective strategy for the removal of environmental pollutants. However, the development of low-cost and high-efficiency photocatalysts continues to present a significant challenge. This work reported the fabrication of a composite photocatalyst directly from waste biomass (rice hulls) in a single step, which efficiently degraded oxytetracycline (OTCs) under sunlight. The morphology, microstructures and photoelectric features of the fabricated materials were subjected to comprehensive investigation using characterization techniques. The results found that the improved photocatalytic activity in sunlight was attributed to the complexation of rice hull-derived biochar and nano-ZnO generated in the preparation, which exhibited favourable adsorption, conductivity characteristics and small bandgap. The photocatalytic efficiency was observed to reach 72.6 % in 120 min under the irradiation of a 100 W xenon lamp. The effect of natural waters, degradation kinetics and degradation TOC analysis were also examined. The dominant agent responsible for the degradation of OTCs was the •O2− radical. Furthermore, the principal photocatalytic degradation pathway of OTCs was identified with the assistance of UHPLC/MS.

Chemical and Toxicological Analysis of Territories Affected by Radiation and Chemical Pollutants: III. Peroxide Oxidation of Lipids and Toxicity Effects of Natural Water (in vivo Studies)

The toxic properties of river water and groundwater samples taken in the Zhizdrinskii and Ul’yanovskii districts of the Kaluga Oblast, which were the areas most exposed to long-lived radioisotopes in consequence of the accident at the Chernobyl nuclear power plant, are studied using bioassay methods based on an analysis of the cumulative effect of toxic substances that are present in the analyzed water sample on the lipid peroxidation (LPO) processes. The concentrations of LPO products and extracellular DNA in the blood plasma of mice, the frequency of chromosomal aberrations in bone marrow cells of mice, the antioxidant status of mouse tissues, and the total number of alterations in the structure of DNA molecules of mouse blood lymphocytes, as estimated based on the value of the relative rate constant of alkaline elution, are determined in in vivo experiments with a single per os administration of hexane–ether extracts from drinking water to experimental animals. The concentration of LPO products in native water samples is determined in the in vitro experiments using LPO liposomes obtained from lecithin, i.e., egg yolk phospholipid, as a model test system. The total set of the obtained data indicates the presence of a relationship between the parameters of the LPO control system and DNA damage and makes it possible to propose a method for the initiated oxidation of liposomes produced from lecithin that can be used in the initial assessment of the intensity of LPO in an aqueous medium.

The modifying effect of natural waters on the toxicity of heavy metals for algae Chlorella vulgaris

The character of the effect of heavy metals (copper, zinc, and cadmium) on a test-culture of chlorella algae in natural waters (the Yenisei and Kacha rivers) is studied. The toxicity of metals in samples of those waters can decrease significantly. The extent of decrease in the toxic effect of the examined pollutants depends on the type of the tested water and significantly varies over time.

Consideration on the effects of natural water containing vanadium on diabetic mellitus

Consideration on the effects of natural water containing vanadium on diabetic mellitus

Effect of mixing and curing waters on the behaviour of cement pastes and concrete Part 2: Properties of cement paste and concrete

The effect of natural waters on the setting time of some hydraulic cements and on the compressive strength of the corresponding concrete is investigated. The setting time of ordinary portland cement is most affected by the water type followed by the sulfate resisting cement; the mixed cement (El-Karnak) and the portland blastfurnace slag cement are quite insensitive. The compressive strength of plain concrete cubes aged up to 17 months is unaffected by the type of mixing and curing water.

Pseudomonas aeruginosa for the evaluation of swimming pool chlorination and algicides.

Concentrations of ammonia and the chlorine stabilizer, cyanuric acid, which could be expected in swimming pools decreased the rate of kill by chlorine of the potential pathogen, Pseudomonas aeruginosa. The effect of cyanuric acid increased as the concentration of chlorine decreased, a fact of significance from a public health view. Quaternary ammonium algcides had little effect on the kill rate of chlorine, but an organic mercury algicide had a synergistic effect with chlorine when the chlorine activity was stressed by the addition of ammonia or the use of 100 times the normal concentration of bacteria. The effect of natural waters, rain, beaches, and swimming pools on the kill rate by 0.5 mg of chlorine per liter indicated that a treatment time of 1 hr or more was required to kill 99.9% of 10(6)Pseudomonas cells per ml. The synergism of chlorine and the organic mercury algicide was also demonstrated with these waters and with sewage treatment plant effluents. The necessity of developing and using laboratory tests which simulate conditions in swimming pools with heavy loads of swimmers, as opposed to tests in chlorine demand-free conditions, is discussed. Samples taken from well-supervised swimming pools when the swimmer load had been especially high required treatment times of 1 to 3 hr to obtain 99.9% kills of the potential pathogen, P. aeruginosa, with 0.5 mg of chlorine per liter.

Pseudomonas aeruginosa for the Evaluation of Swimming Pool Chlorination and Algicides

Concentrations of ammonia and the chlorine stabilizer, cyanuric acid, which could be expected in swimming pools decreased the rate of kill by chlorine of the potential pathogen, Pseudomonas aeruginosa. The effect of cyanuric acid increased as the concentration of chlorine decreased, a fact of significance from a public health view. Quaternary ammonium algcides had little effect on the kill rate of chlorine, but an organic mercury algicide had a synergistic effect with chlorine when the chlorine activity was stressed by the addition of ammonia or the use of 100 times the normal concentration of bacteria. The effect of natural waters, rain, beaches, and swimming pools on the kill rate by 0.5 mg of chlorine per liter indicated that a treatment time of 1 hr or more was required to kill 99.9% of 10(6)Pseudomonas cells per ml. The synergism of chlorine and the organic mercury algicide was also demonstrated with these waters and with sewage treatment plant effluents. The necessity of developing and using laboratory tests which simulate conditions in swimming pools with heavy loads of swimmers, as opposed to tests in chlorine demand-free conditions, is discussed. Samples taken from well-supervised swimming pools when the swimmer load had been especially high required treatment times of 1 to 3 hr to obtain 99.9% kills of the potential pathogen, P. aeruginosa, with 0.5 mg of chlorine per liter.