Kelley, Keven M.;Stenson, Alexandra C.;Dey, Rajarashi;Whelton, Andrew J. published 《Release of drinking water contaminants and odor impacts caused by green building cross-linked polyethylene (PEX) plumbing systems》. The research results were published in《Water Research》 in 2014.COA of Formula: C8H18O2 The article conveys some information:
Green buildings are increasingly being plumbed with crosslinked polyethylene (PEX) potable water pipe. Tap water quality was investigated at a six month old plumbing system and chem. and odor quality impacts of six PEX pipe brands were examined Eleven PEX related contaminants were found in the plumbing system; one regulated (toluene) and several unregulated: Antioxidant degradation products, resin solvents, initiator degradation products, or manufacturing aides. Water chem. and odor quality was monitored for new PEX-a, -b and -c pipes with (2 mg/L free chlorine) and without disinfectant over 30 days. Odor and total organic carbon (TOC) levels decreased for all pipes, but odor remained greater than the USA’s Environmental Protection Agency’s (USEPA) secondary maximum contaminant level. Odors were not attributed to known odorants ethyl-tert-Bu ether (ETBE) or methyl-tert-Bu ether (MTBE). Free chlorine caused odor levels for PEX-a1 pipe to increase from 26 to 75 threshold odor number (TON) on day 3 and affected the rate at which TOC changed for each brand over 30 days. As TOC decreased, the UV absorbance at 254 nm increased. Pipes consumed as much as 0.5 mg/L as Cl2 during each 3 day stagnation period. Sixteen organic chems. were identified, including toluene, pyridine, methylene trichloroacetate and 2,4-di-tert-butylphenol. Some were also detected during the plumbing system field investigation. Six brands of PEX pipes sold in the USA and a PEX-a green building plumbing system impacted chem. and drinking water odor quality. To complete the study, the researchers used 2,5-Dimethyl-2,5-hexanediol (cas: 110-03-2) .
2,5-Dimethyl-2,5-hexanediol(cas:110-03-2) on heteropoly acid catalyzed dehydration yields cyclic ethers via stereospecific intramolecular SN2 mechanism. It reacts with nitriles in concentrated sulfuric acid to yield Δ1-pyrrolines.COA of Formula: C8H18O2
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