Wastewater of hospitals can cause many risks to public health due to having a variety of pathogenic microorganisms, pharmaceutical substances, and other hazardous toxic substances. The aim of this study was to evaluate the chemical quality of effluents from wastewater treatment plant of Falsafi Hospital and Hakim Jorjani Hospital in Gorgan, Iran, and to compare them technically and economically...

Polar stratospheric clouds (PSCs) are extremely efficient at catalysing the transformation of photostable chlorine reservoirs into photolabile species, which are actively involved in springtime ozone-depletion events. Why PSCs are such efficient catalysts, however, is not well understood. Here, we investigate the freezing behaviour of ternary HNO₃-H₂SO₄-H₂O droplets of micrometric size, which f...

Results of our experiments showed that the attachment of bacteria to surfaces provided the greatest increase in disinfection resistance. Attachment of unencapsulated Klebsiella pneumoniae grown in medium with high levels of nutrients to glass microscope slides afforded the microorganisms as much as a 150-fold increase in disinfection resistance. Other mechanisms which increased disinfection res...

Determination of the more common light elements such as nitrogen and chlorine at trace levels is difficult because of their high abundance on sample surfaces, in materials used to build analysis instruments, and in the residual gas of the instrument vacuum. We present here a new approach to analysis of these elements: accelerator mass spectrometry (AMS) combined with neutron activation. The pro...

Isocyanuric acid (commonly referred to in the swimming pool/spa industry as cyanuric acid, stabilizer, conditioner, CYA, etc., and referred to simply as cyanuric acid in this paper) is a member of the symmetrical triazine family, and it is used in outdoor swimming pools and spas to protect chlorine against loss from ultraviolet radiation from the sun. Depending on factors such as season and cli...