{"id":2368,"date":"2016-06-14T00:37:33","date_gmt":"2016-06-14T07:37:33","guid":{"rendered":"http:\/\/www.waterandwastewatercourses.com\/?p=2368"},"modified":"2018-10-12T16:12:15","modified_gmt":"2018-10-12T23:12:15","slug":"calculate-detention-time","status":"publish","type":"post","link":"https:\/\/www.waterandwastewatercourses.com\/calculate-detention-time\/","title":{"rendered":"How to calculate detention time"},"content":{"rendered":"<p><span style=\"font-family: helvetica, arial, sans-serif; font-size: 14pt;\">In today&#8217;s post, we&#8217;ll learn how to calculate detention time. \u00a0It&#8217;s a common question on the operator certification exam, so be sure to understand this concept. \u00a0This applies to both water and wastewater treatment. \u00a0<\/span><\/p>\n<p><span style=\"font-family: helvetica, arial, sans-serif; font-size: 14pt;\">\u00a0For more help, enroll in our <a href=\"http:\/\/water-and-wastewater-courses.teachable.com\">online courses<\/a>\u00a0or try these\u00a0<a href=\"https:\/\/amzn.to\/2xKZct2\">practice exams<\/a>.\u00a0 \u00a0 \u00a0\u00a0<\/span><\/p>\n<p><iframe src=\"https:\/\/www.youtube.com\/embed\/T0rc238iNds\" width=\"560\" height=\"315\" frameborder=\"0\" allowfullscreen=\"allowfullscreen\"><\/iframe><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-family: helvetica, arial, sans-serif; font-size: 14pt;\">So what is detention time? \u00a0It&#8217;s the amount of time it takes for a drop of water to pass through a basin or a tank. \u00a0For example, if someone asked you to find out how long it takes the flow to reach the outlet of a rectangular clarifier, they&#8217;re asking you to calculate the detention time.<\/span><\/p>\n<p>&nbsp;<\/p>\n<h2><span style=\"font-family: helvetica, arial, sans-serif; font-size: 14pt;\">So, how do you calculate detention time?\u00a0\u00a0<\/span><\/h2>\n<p>&nbsp;<\/p>\n<p><span style=\"font-family: helvetica, arial, sans-serif; font-size: 14pt;\">Here&#8217;s the formula for detention time:<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><a href=\"https:\/\/www.waterandwastewatercourses.com\/wp-content\/uploads\/2016\/06\/detentino-time.001.jpeg\"><img fetchpriority=\"high\" decoding=\"async\" class=\"aligncenter  wp-image-2772\" src=\"https:\/\/www.waterandwastewatercourses.com\/wp-content\/uploads\/2016\/06\/detentino-time.001.jpeg\" alt=\"detention time\" width=\"419\" height=\"177\" srcset=\"https:\/\/www.waterandwastewatercourses.com\/wp-content\/uploads\/2016\/06\/detentino-time.001.jpeg 225w, https:\/\/www.waterandwastewatercourses.com\/wp-content\/uploads\/2016\/06\/detentino-time.001-120x51.jpeg 120w\" sizes=\"(max-width: 419px) 100vw, 419px\" \/><\/a><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-family: helvetica, arial, sans-serif; font-size: 14pt;\">Detention time is calculated by dividing the volume of the tank or basin by the flow rate.\u00a0 It&#8217;s fairly simple and straight-forward.\u00a0<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-family: helvetica, arial, sans-serif; font-size: 14pt;\">The most challenging part of calculating detention time is making sure the units on the top and bottom of the formula cancel out.\u00a0 \u00a0\u00a0<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-family: helvetica, arial, sans-serif; font-size: 14pt;\">Most exam questions will give you the dimensions of the clarifier in feet, but the flow rate is usually given in MGD or gallons\/day. \u00a0This means that the volume you calculate will initially be in cubic feet, which you&#8217;ll convert to gallons. \u00a0You want to make sure that the gallons cancel out to obtain the answer in hours.<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-family: helvetica, arial, sans-serif; font-size: 14pt;\">When you&#8217;re converting units on the exam, be very careful.\u00a0 It&#8217;s easy to make mistakes when you&#8217;re rushing to complete the exam.\u00a0 Often, when I check my students&#8217; math problems, I see mistakes that were made, probably because they were in a rush to complete the problem.\u00a0 The bottom line is to be very careful when you&#8217;re solving any math problem.\u00a0<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-family: helvetica, arial, sans-serif; font-size: 14pt;\">For both water and wastewater treatment, the detention time for clarifiers is usually in the range of 2 to 3 hours. \u00a0The reason why the flow spends a long time in the clarifier is to enable the solids to settle to the bottom. \u00a0Otherwise, you&#8217;ll see more solids in the effluent of the clarifier.<\/span><\/p>\n<p>&nbsp;<\/p>\n<h2><strong><span style=\"font-family: helvetica, arial, sans-serif;\"><span style=\"font-size: 18.6667px;\">HELPFUL RESOURCES:<\/span><\/span><\/strong><\/h2>\n<p><span style=\"font-family: helvetica, arial, sans-serif; font-size: 14pt;\"><a href=\"https:\/\/amzn.to\/2xKZct2\">Practice Exams<\/a><\/span><\/p>\n<p><span style=\"font-family: helvetica, arial, sans-serif; font-size: 14pt;\"><a href=\"https:\/\/water-and-wastewater-courses.teachable.com\/\">Online Courses<\/a><\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-family: helvetica, arial, sans-serif; font-size: 14pt;\">If you have any questions, please contact me at this <a href=\"https:\/\/www.waterandwastewatercourses.com\/contact-us\/\">link<\/a>.\u00a0 I&#8217;ll do everything I can to help you.<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"<p>In today&#8217;s post, we&#8217;ll learn how to calculate detention time. \u00a0It&#8217;s a common question on the operator certification exam, so be sure to understand this concept. \u00a0This applies to both water and wastewater treatment. \u00a0 \u00a0For more help, enroll in our online courses\u00a0or try these\u00a0practice exams.\u00a0 \u00a0 \u00a0\u00a0 &nbsp; So what is detention time? \u00a0It&#8217;s &hellip;<\/p>\n<p class=\"read-more\"> <a class=\"ast-button\" href=\"https:\/\/www.waterandwastewatercourses.com\/calculate-detention-time\/\"> <span class=\"screen-reader-text\">How to calculate detention time<\/span> Read More \u00bb<\/a><\/p>\n","protected":false},"author":1,"featured_media":2381,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[94,111],"tags":[],"class_list":["post-2368","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-wastewater-math-practice-problems","category-water-math"],"jetpack_featured_media_url":"https:\/\/www.waterandwastewatercourses.com\/wp-content\/uploads\/2016\/06\/circ-clarifier.jpg","_links":{"self":[{"href":"https:\/\/www.waterandwastewatercourses.com\/wp-json\/wp\/v2\/posts\/2368","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.waterandwastewatercourses.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.waterandwastewatercourses.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.waterandwastewatercourses.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.waterandwastewatercourses.com\/wp-json\/wp\/v2\/comments?post=2368"}],"version-history":[{"count":13,"href":"https:\/\/www.waterandwastewatercourses.com\/wp-json\/wp\/v2\/posts\/2368\/revisions"}],"predecessor-version":[{"id":2773,"href":"https:\/\/www.waterandwastewatercourses.com\/wp-json\/wp\/v2\/posts\/2368\/revisions\/2773"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.waterandwastewatercourses.com\/wp-json\/wp\/v2\/media\/2381"}],"wp:attachment":[{"href":"https:\/\/www.waterandwastewatercourses.com\/wp-json\/wp\/v2\/media?parent=2368"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.waterandwastewatercourses.com\/wp-json\/wp\/v2\/categories?post=2368"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.waterandwastewatercourses.com\/wp-json\/wp\/v2\/tags?post=2368"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}