{"id":53,"date":"2021-06-21T21:09:48","date_gmt":"2021-06-21T21:09:48","guid":{"rendered":"https:\/\/books.gw-project.org\/septic-system-impacts-on-groundwater-quality\/chapter\/acid-buffering-reactions\/"},"modified":"2021-06-22T22:24:43","modified_gmt":"2021-06-22T22:24:43","slug":"acid-buffering-reactions","status":"publish","type":"chapter","link":"https:\/\/books.gw-project.org\/septic-system-impacts-on-groundwater-quality\/chapter\/acid-buffering-reactions\/","title":{"raw":"7.1  Acid Buffering Reactions","rendered":"7.1  Acid Buffering Reactions"},"content":{"raw":"<div class=\"acid-buffering-reactions\">\r\n<p class=\"import-Normal\">Four common acid buffering reactions are important to controlling pH in the unsaturated zone which in turn influences the fate of phosphorus in septic system plumes. These acid buffering reactions involve dissolution of carbonate minerals and gibbsite, as well as two types of ferrihydrite dissolution. These reactions are as follows:<\/p>\r\n\r\n<ul>\r\n \t<li class=\"import-Normal\">carbonate mineral dissolution as shown in Equation 18;<\/li>\r\n<\/ul>\r\n<table style=\"border: none; border-collapse: collapse; width: 100%;\">\r\n<tbody>\r\n<tr>\r\n<td style=\"width: 10%;\"><\/td>\r\n<td style=\"width: 80%; text-align: center;\"><em>CaCO<\/em><sub><em>3<\/em><\/sub> <em>+ H<\/em><sup><em>+<\/em><\/sup><em> \u2192 HCO<\/em><sub><em>3<\/em><\/sub><sup><em>-<\/em><\/sup> <em>+ Ca<\/em><sup><em>2+<\/em><\/sup><\/td>\r\n<td style=\"width: 10%; text-align: right;\">(18)<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<ul>\r\n \t<li class=\"import-Normal\">gibbsite dissolution as shown in Equation 19;<a id=\"equation19\"><\/a><\/li>\r\n<\/ul>\r\n<table style=\"border: none; border-collapse: collapse; width: 100%;\">\r\n<tbody>\r\n<tr>\r\n<td style=\"width: 10%;\"><\/td>\r\n<td style=\"width: 80%; text-align: center;\"><em>Al(<\/em><em>OH)<\/em><sub><em>3<\/em><\/sub><em> + 3H<\/em><sup><em>+<\/em><\/sup> <em>\u2192 Al<\/em><sup><em>3<\/em><\/sup><sup><em>+<\/em><\/sup> <em>+ 3H<\/em><sub><em>2<\/em><\/sub><em>O<\/em><\/td>\r\n<td style=\"width: 10%; text-align: right;\">(19)<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<ul>\r\n \t<li class=\"import-Normal\">ferrihydrite dissolution as shown in Equation 20;<a id=\"equation20\"><\/a><\/li>\r\n<\/ul>\r\n<table style=\"border: none; border-collapse: collapse; width: 100%;\">\r\n<tbody>\r\n<tr>\r\n<td style=\"width: 10%;\"><\/td>\r\n<td style=\"width: 80%; text-align: center;\"><em>Fe(<\/em><em>OH)<\/em><sub><em>3<\/em><\/sub><em> + 3H<\/em><sup><em>+<\/em><\/sup> <em>\u2192<\/em> <em>Fe<\/em><sup><em>3+<\/em><\/sup><em> + 3H<\/em><sub><em>2<\/em><\/sub><em>O<\/em><\/td>\r\n<td style=\"width: 10%; text-align: right;\">(20)<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<ul>\r\n \t<li class=\"import-Normal\">and, reductive dissolution of ferrihydrite as shown in Equation 21.<\/li>\r\n<\/ul>\r\n<table style=\"border: none; border-collapse: collapse; width: 100%;\">\r\n<tbody>\r\n<tr>\r\n<td style=\"width: 10%;\"><\/td>\r\n<td style=\"width: 80%; text-align: center;\"><em>4<\/em><em>Fe(<\/em><em>OH)<\/em><sub><em>3<\/em><\/sub><em> + CH<\/em><sub><em>2<\/em><\/sub><em>O + 7H<\/em><sup><em>+<\/em><\/sup><em>\u2192 4Fe<\/em><sup><em>2+<\/em><\/sup><em> + HCO<\/em><sub><em>3<\/em><\/sub><sup><em>-<\/em><\/sup> <em>+ 10H<\/em><sub><em>2<\/em><\/sub><em>O<\/em><\/td>\r\n<td style=\"width: 10%; text-align: right;\">(21)<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<p class=\"import-Normal\">Lower pH increases the potential for reactions presented in Section 7.2 that precipitate phosphorus, thus remove phosphorus from the waste water. Consequently, at sites where the reactions shown in Equations 18 through 21 are more likely to occur, there is a greater assimilation capacity for phosphorus in the unsaturated zone below a septic system.<\/p>\r\n\r\n<\/div>","rendered":"<div class=\"acid-buffering-reactions\">\n<p class=\"import-Normal\">Four common acid buffering reactions are important to controlling pH in the unsaturated zone which in turn influences the fate of phosphorus in septic system plumes. These acid buffering reactions involve dissolution of carbonate minerals and gibbsite, as well as two types of ferrihydrite dissolution. These reactions are as follows:<\/p>\n<ul>\n<li class=\"import-Normal\">carbonate mineral dissolution as shown in Equation 18;<\/li>\n<\/ul>\n<table style=\"border: none; border-collapse: collapse; width: 100%;\">\n<tbody>\n<tr>\n<td style=\"width: 10%;\"><\/td>\n<td style=\"width: 80%; text-align: center;\"><em>CaCO<\/em><sub><em>3<\/em><\/sub> <em>+ H<\/em><sup><em>+<\/em><\/sup><em> \u2192 HCO<\/em><sub><em>3<\/em><\/sub><sup><em>&#8211;<\/em><\/sup> <em>+ Ca<\/em><sup><em>2+<\/em><\/sup><\/td>\n<td style=\"width: 10%; text-align: right;\">(18)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<ul>\n<li class=\"import-Normal\">gibbsite dissolution as shown in Equation 19;<a id=\"equation19\"><\/a><\/li>\n<\/ul>\n<table style=\"border: none; border-collapse: collapse; width: 100%;\">\n<tbody>\n<tr>\n<td style=\"width: 10%;\"><\/td>\n<td style=\"width: 80%; text-align: center;\"><em>Al(<\/em><em>OH)<\/em><sub><em>3<\/em><\/sub><em> + 3H<\/em><sup><em>+<\/em><\/sup> <em>\u2192 Al<\/em><sup><em>3<\/em><\/sup><sup><em>+<\/em><\/sup> <em>+ 3H<\/em><sub><em>2<\/em><\/sub><em>O<\/em><\/td>\n<td style=\"width: 10%; text-align: right;\">(19)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<ul>\n<li class=\"import-Normal\">ferrihydrite dissolution as shown in Equation 20;<a id=\"equation20\"><\/a><\/li>\n<\/ul>\n<table style=\"border: none; border-collapse: collapse; width: 100%;\">\n<tbody>\n<tr>\n<td style=\"width: 10%;\"><\/td>\n<td style=\"width: 80%; text-align: center;\"><em>Fe(<\/em><em>OH)<\/em><sub><em>3<\/em><\/sub><em> + 3H<\/em><sup><em>+<\/em><\/sup> <em>\u2192<\/em> <em>Fe<\/em><sup><em>3+<\/em><\/sup><em> + 3H<\/em><sub><em>2<\/em><\/sub><em>O<\/em><\/td>\n<td style=\"width: 10%; text-align: right;\">(20)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<ul>\n<li class=\"import-Normal\">and, reductive dissolution of ferrihydrite as shown in Equation 21.<\/li>\n<\/ul>\n<table style=\"border: none; border-collapse: collapse; width: 100%;\">\n<tbody>\n<tr>\n<td style=\"width: 10%;\"><\/td>\n<td style=\"width: 80%; text-align: center;\"><em>4<\/em><em>Fe(<\/em><em>OH)<\/em><sub><em>3<\/em><\/sub><em> + CH<\/em><sub><em>2<\/em><\/sub><em>O + 7H<\/em><sup><em>+<\/em><\/sup><em>\u2192 4Fe<\/em><sup><em>2+<\/em><\/sup><em> + HCO<\/em><sub><em>3<\/em><\/sub><sup><em>&#8211;<\/em><\/sup> <em>+ 10H<\/em><sub><em>2<\/em><\/sub><em>O<\/em><\/td>\n<td style=\"width: 10%; text-align: right;\">(21)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p class=\"import-Normal\">Lower pH increases the potential for reactions presented in Section 7.2 that precipitate phosphorus, thus remove phosphorus from the waste water. Consequently, at sites where the reactions shown in Equations 18 through 21 are more likely to occur, there is a greater assimilation capacity for phosphorus in the unsaturated zone below a septic system.<\/p>\n<\/div>\n","protected":false},"author":1,"menu_order":9,"template":"","meta":{"pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"chapter-type":[],"contributor":[],"license":[],"class_list":["post-53","chapter","type-chapter","status-publish","hentry"],"part":149,"_links":{"self":[{"href":"https:\/\/books.gw-project.org\/septic-system-impacts-on-groundwater-quality\/wp-json\/pressbooks\/v2\/chapters\/53","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/books.gw-project.org\/septic-system-impacts-on-groundwater-quality\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/books.gw-project.org\/septic-system-impacts-on-groundwater-quality\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/books.gw-project.org\/septic-system-impacts-on-groundwater-quality\/wp-json\/wp\/v2\/users\/1"}],"version-history":[{"count":4,"href":"https:\/\/books.gw-project.org\/septic-system-impacts-on-groundwater-quality\/wp-json\/pressbooks\/v2\/chapters\/53\/revisions"}],"predecessor-version":[{"id":242,"href":"https:\/\/books.gw-project.org\/septic-system-impacts-on-groundwater-quality\/wp-json\/pressbooks\/v2\/chapters\/53\/revisions\/242"}],"part":[{"href":"https:\/\/books.gw-project.org\/septic-system-impacts-on-groundwater-quality\/wp-json\/pressbooks\/v2\/parts\/149"}],"metadata":[{"href":"https:\/\/books.gw-project.org\/septic-system-impacts-on-groundwater-quality\/wp-json\/pressbooks\/v2\/chapters\/53\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/books.gw-project.org\/septic-system-impacts-on-groundwater-quality\/wp-json\/wp\/v2\/media?parent=53"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/books.gw-project.org\/septic-system-impacts-on-groundwater-quality\/wp-json\/pressbooks\/v2\/chapter-type?post=53"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/books.gw-project.org\/septic-system-impacts-on-groundwater-quality\/wp-json\/wp\/v2\/contributor?post=53"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/books.gw-project.org\/septic-system-impacts-on-groundwater-quality\/wp-json\/wp\/v2\/license?post=53"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}