Lomboy M, Riego de Dios J, Magtibay B, Quizon R, Molina V, Fadrilan-Camacho V, See J, Enoveso A, Barbosa L, Agravante A. Updating national standards for drinking-water: a Philippine experience. Journal of water and health. 2017 Apr;15(2):288-295. doi: 10.2166/wh.2016.177.
The latest version of the Philippine National Standards for Drinking-Water (PNSDW) was issued in 2007 by the Department of Health (DOH). Due to several issues and concerns, the DOH decided to make an update which is relevant and necessary to meet the needs of the stakeholders. As an output, the water quality parameters are now categorized into mandatory, primary, and secondary. The ten mandatory parameters are core parameters which all water service providers nationwide are obligated to test. These include thermotolerant coliforms or Escherichia coli, arsenic, cadmium, lead, nitrate, color, turbidity, pH, total dissolved solids, and disinfectant residual. The 55 primary parameters are site-specific and can be adopted as enforceable parameters when developing new water sources or when the existing source is at high risk of contamination. The 11 secondary parameters include operational parameters and those that affect the esthetic quality of drinking-water. In addition, the updated PNSDW include new sections: (1) reporting and interpretation of results and corrective actions; (2) emergency drinking-water parameters; (3) proposed Sustainable Development Goal parameters; and (4) standards for other drinking-water sources. The lessons learned and insights gained from the updating of standards are likewise incorporated in this paper.
Zhang Evan G R Davies James Bolton Yang Liu Q. Monochloramine loss mechanisms in tap water. Water Environ Res. 2017 Mar 1. doi: 10.2175/106143017X14902968254421.
Chloramination has been widely applied for drinking water disinfection, with monochloramine (NH₂Cl) the dominant chloramine species. However, under neutral pH, NH₂Cl can autodecompose and react with chemical components in drinking water, thus decreasing disinfection efficiency. In tap water, the NH₂Cl loss rate can be influenced by temperature, pH, Cl/N molar ratio, the initial NH₂Cl concentration and the natural organic matter (NOM) concentration. A good prediction of NH2Cl loss can assist in the operation of drinking water treatment plants. In this research, a kinetic rate constant (k_docr=(3.57 ± 0.54)×〖10〗^6 〖 M〗^(-1) h^(-1)) and a reactive site fraction (S = 0.43 ± 0.06) for the reaction between free chlorine released from NH₂Cl autodecoposition and tap water NOM were derived from a kinetic model to predict the NH₂Cl loss under various conditions. A temperature-dependent model was also developed. The model predictions match well with the experimental results, which demonstrates the validity of the model and provides a convenient and accurate method for NH₂Cl loss calculations.
“20 years ago climate models were celebrated as a huge breakthrough. Finally we were able to reproduce reality in the computer, which had been becoming ever more powerful and faster. Everyone believed that only minor adjustments were necessary, and the target would be reached. But when the computer-crunched results were finally compared to reality, huge unexplained discrepancies appeared.” click here for Notrickszone.
A conference attendee posted a summary of major points made by speakers at the conference here.
Conference live stream archive videos can be viewed here.
“This new move by the architects of Brexit to split California into two separate states, along the lines of Virginia and West Virginia is likely to draw support from those who have been fighting to do exactly that for decades.” click here
“The water district that manages Silicon Valley’s 235-foot-high earthen Anderson Dam, which holds 29 billion gallons of water, has acknowledged that the dam’s embankments are seismically unstable and could catastrophically liquefy in a major earthquake.” click here
“One of the consequences of extended periods of low solar activity is that it can result in an increase in cosmic rays that can penetrate into the Earth’s upper atmosphere. Galactic cosmic rays are high-energy particles originating from space that impact the Earth’s atmosphere. Most of the incoming cosmic ray particles are protons and they actually arrive as individual particles – not in the form of a ray as the term “ray” would suggest. Usually, cosmic rays are held at bay by the sun’s magnetic field, which envelops and protects all the planets in the solar system. But the sun’s magnetic shield is weakening as the current solar cycle heads towards the next solar minimum and this allows more cosmic rays to reach the Earth’s atmosphere.” click here