Water Environment Federation (WEF) Discussion ForumsWater Environment Federation (WEF) Discussion Forumshttp://www.wef.org/TechnicalDiscussions/jfuller@wef.orgThu, 21 Aug 2008 22:13:12 GMT20http://www.wef.org/TechnicalDiscussions/Topic5737-12-1.aspxFouling is mostly Calcium and Magnesium Carbonate, but can contain metals such as iron, which is present in the source water. I carried out laboratory tests on solutions to clean badly fouled quartz sleeves, from a wastewater application. Sleeves were soaked in the solution for 30 min.<P>Phosphoric acid at 5 to 10% was very good. This equates to a 10:1 dilution for once off use. </P><P>20% (hydrated) citric acid solution was about 50% effective. You should perhaps try 50% solution.</P><P>Sulfuric and hydrochloric acid were very good, however there are corrosion issues with stainless steel.</P><P>Vinegar did not achieve any reduction in fouling.</P><P>If there are other metals present then hopefully when the CaCO3 matrix is removed the metal will be mobilised. However if iron or other staining is present then you may need to resort to nitric acid in the mix (but be very careful with such strong acids)</P><P>A useful test to confirm reduction in fouling is to remove the sleeve from the reactor, rinse with a little potable water and then let it air dry. The sleeve must be sparkling clean to have zero fouling. A moderate level of cloudiness is the usual design limit for fouling, which usually equates to a fouling factor of 75% (unwiped sleeves).</P><P>Regards</P><P>Grant H (Melbourne, Aust) Thu, 02 Aug 2007 21:17:06 GMT01780898http://www.wef.org/TechnicalDiscussions/Topic5737-12-1.aspxI have heard of people using rainx on their blubs to keep them from getting dirty. I am not sure if this works but its worth a try.Tue, 10 Jul 2007 00:38:13 GMTnicholas1982http://www.wef.org/TechnicalDiscussions/Topic5737-12-1.aspxWeak organic acids and strong mineral acids will remove scale deposits. Citric acid is indeed quite common. Other organic acids (e.g. acetic/oxalic) should work equally as well. Of course any of the strong mineral acids (muriatic, sulfuric, phosphoric) will work but require dilution.</P><P>Peroxide is an oxidant. If the foulant is organic based then it may be useful, if it is scale based then it will not. Since you have been using phosphoric acid successfully then it appears that your foulant is not organic based and oxidants are not needed.Mon, 09 Jul 2007 14:22:07 GMTBill Gaineshttp://www.wef.org/TechnicalDiscussions/Topic5737-12-1.aspxMost of the operators I know have been using citric acid.Tue, 03 Jul 2007 13:50:19 GMTJohn Sansalonehttp://www.wef.org/TechnicalDiscussions/Topic5737-12-1.aspxDoes anyone have any suggestions on chemicals for cleaning the glass sleeves for UV Bulbs. We currently are using 165 gls. of Phosphoric acid 85% diluted will about 1000 gls of water. We are looking for something that will be safe for operators, We have heard of Peroxide and Vinager but are not sure of the results.Tue, 03 Jul 2007 11:24:41 GMTDave Peters