{"id":2065,"date":"2026-10-14T16:49:16","date_gmt":"2026-10-14T15:49:16","guid":{"rendered":"https:\/\/wpcalc.com\/pt\/quimica\/calculadora-dbo\/"},"modified":"2026-10-14T16:49:16","modified_gmt":"2026-10-14T15:49:16","slug":"calculadora-dbo","status":"publish","type":"post","link":"https:\/\/wpcalc.com\/pt\/quimica\/calculadora-dbo\/","title":{"rendered":"Calculadora de Demanda Bioqu\u00edmica de Oxig\u00eanio (DBO\u2085)"},"content":{"rendered":"<section class=\"not-prose calculator-box\" aria-labelledby=\"calculator-title\"><div class=\"flex items-baseline sm:items-center justify-between gap-2 sm:gap-3\"><div class=\"flex flex-col sm:flex-row sm:items-center gap-2\"><span class=\"icon icon-calculator text-primary-700! text-base! dark:text-primary-300!\" aria-hidden=\"true\"><\/span><h2 id=\"calculator-title\" class=\"text-lg font-display font-bold\">Calcule a DBO\u2085 a partir de uma amostra dilu\u00edda<\/h2><\/div><div class=\"calcdash-favorite group\">\n  <button type=\"button\" class=\"favorite\" id=\"favorite\" data-favorite-id=\"2065\" data-favorite-title=\"Demanda Bioqu\u00edmica de Oxig\u00eanio\" data-favorite-url=\"https:\/\/wpcalc.com\/pt\/quimica\/calculadora-dbo\/\" data-favorite-excerpt=\"Calcule a demanda bioqu\u00edmica de oxig\u00eanio de 5 dias (DBO\u2085) de uma amostra de \u00e1gua dilu\u00edda a partir do oxig\u00eanio dissolvido inicial e final, da fra\u00e7\u00e3o de dilui\u00e7\u00e3o e da corre\u00e7\u00e3o opcional por semente, conforme o m\u00e9todo padr\u00e3o APHA 5210B.\" aria-label=\"Adicionar aos favoritos\" data-favorite-icon=\"icon icon-biology\">\n    <span class=\"icon icon-shape-star-empty\" aria-hidden=\"true\"><\/span>\n  <\/button>\n  <div class=\"calcdash-favorite__tip\" aria-hidden=\"true\">\n   <span class=\"favorite-tooltip\" id=\"favorite-tooltip\"><\/span>\n  <\/div>\n  <span class=\"sr-only\" role=\"status\" id=\"favorite-status\"><\/span>\n<\/div><\/div><form action=\"https:\/\/wpcalc.com\/pt\/quimica\/calculadora-dbo\/\" method=\"POST\" class=\"calculator\" id=\"calculator-2065\" data-post=\"2065\"><fieldset class=\"fieldset-input is-2\"><legend class=\"sr-only\">Campos de entrada<\/legend><div class=\"is-single field\" id=\"input-1\"><span class=\"font-semibold\">Frasco da amostra dilu\u00edda<\/span><\/div><div class=\"field has-term\" id=\"input-2\"><label for=\"field-2\">OD inicial (D\u2081)<\/label><div class=\"term\">D\u2081<\/div>  <div class=\"absolute bottom-0 left-16 top-8 w-2 h-0.5 bg-blue-500\"><\/div><input type=\"text\" name=\"od_inicial_d\" id=\"field-2\" aria-describedby=\"calc-unit-2 calc-info-2\" data-number inputmode=\"decimal\" autocomplete=\"off\" spellcheck=\"false\" placeholder=\"e.g. 9.0\" min=\"0\" value=\"9\"\/><div class=\"unit\" id=\"calc-unit-2\">mg\/L<\/div><small id=\"calc-info-2\">Oxig\u00eanio dissolvido medido na amostra dilu\u00edda logo ap\u00f3s o preparo (dia 0).<\/small><\/div><div class=\"field has-term\" id=\"input-3\"><label for=\"field-3\">OD final ap\u00f3s 5 dias (D\u2082)<\/label><div class=\"term\">D\u2082<\/div>  <div class=\"absolute bottom-0 left-16 top-8 w-2 h-0.5 bg-blue-500\"><\/div><input type=\"text\" name=\"od_final_aps_5_dias_d\" id=\"field-3\" aria-describedby=\"calc-unit-3 calc-info-3\" data-number inputmode=\"decimal\" autocomplete=\"off\" spellcheck=\"false\" placeholder=\"e.g. 4.2\" min=\"0\" value=\"4.2\"\/><div class=\"unit\" id=\"calc-unit-3\">mg\/L<\/div><small id=\"calc-info-3\">Oxig\u00eanio dissolvido remanescente no mesmo frasco ap\u00f3s 5 dias de incuba\u00e7\u00e3o a 20 \u00b0C no escuro.<\/small><\/div><div class=\"is-single field\" id=\"input-4\"><span class=\"font-semibold\">Dilui\u00e7\u00e3o<\/span><\/div><div class=\"field has-term\" id=\"input-5\"><label for=\"field-5\">Fra\u00e7\u00e3o de dilui\u00e7\u00e3o (P)<\/label><div class=\"term\">P<\/div>  <div class=\"absolute bottom-0 left-16 top-8 w-2 h-0.5 bg-blue-500\"><\/div><input type=\"text\" name=\"frao_de_diluio_p\" id=\"field-5\" aria-describedby=\"calc-unit-5 calc-info-5\" data-number inputmode=\"decimal\" autocomplete=\"off\" spellcheck=\"false\" placeholder=\"e.g. 5\" min=\"0\" max=\"100\" value=\"5\"\/><div class=\"unit\" id=\"calc-unit-5\">%<\/div><small id=\"calc-info-5\">Fra\u00e7\u00e3o do volume final do frasco que corresponde \u00e0 amostra de \u00e1gua original. Uma dilui\u00e7\u00e3o de 5% significa 1 parte de amostra em 20 partes no total (escolha comum para esgoto).<\/small><\/div><div class=\"is-single field\" id=\"input-6\"><span class=\"font-semibold\">Corre\u00e7\u00e3o da semente (opcional)<\/span><\/div><div class=\"field is-checkbox is-single\" id=\"input-7\"><input type=\"checkbox\" id=\"field-7\" value=\"1\"\/><label for=\"field-7\">Aplicar corre\u00e7\u00e3o da semente<\/label><\/div><div class=\"field has-term\" id=\"input-8\" hidden><label for=\"field-8\">OD inicial do controle da semente (B\u2081)<\/label><div class=\"term\">B\u2081<\/div>  <div class=\"absolute bottom-0 left-16 top-8 w-2 h-0.5 bg-blue-500\"><\/div><input type=\"text\" name=\"od_inicial_do_controle_da_semente_b\" id=\"field-8\" aria-describedby=\"calc-unit-8 calc-info-8\" data-number inputmode=\"decimal\" autocomplete=\"off\" spellcheck=\"false\" placeholder=\"e.g. 9.0\" min=\"0\" value=\"9\"\/><div class=\"unit\" id=\"calc-unit-8\">mg\/L<\/div><small id=\"calc-info-8\">Oxig\u00eanio dissolvido no dia 0 do frasco de controle da semente (\u00e1gua de dilui\u00e7\u00e3o semeada sem amostra).<\/small><\/div><div class=\"field has-term\" id=\"input-9\" hidden><label for=\"field-9\">OD final do controle da semente (B\u2082)<\/label><div class=\"term\">B\u2082<\/div>  <div class=\"absolute bottom-0 left-16 top-8 w-2 h-0.5 bg-blue-500\"><\/div><input type=\"text\" name=\"od_final_do_controle_da_semente_b\" id=\"field-9\" aria-describedby=\"calc-unit-9 calc-info-9\" data-number inputmode=\"decimal\" autocomplete=\"off\" spellcheck=\"false\" placeholder=\"e.g. 6.6\" min=\"0\" value=\"6.6\"\/><div class=\"unit\" id=\"calc-unit-9\">mg\/L<\/div><small id=\"calc-info-9\">Oxig\u00eanio dissolvido do frasco de controle da semente ap\u00f3s 5 dias de incuba\u00e7\u00e3o.<\/small><\/div><div class=\"field has-term\" id=\"input-10\" hidden><label for=\"field-10\">Fra\u00e7\u00e3o da semente (f)<\/label><div class=\"term\">f<\/div>  <div class=\"absolute bottom-0 left-16 top-8 w-2 h-0.5 bg-blue-500\"><\/div><input type=\"text\" name=\"frao_da_semente_f\" id=\"field-10\" aria-describedby=\"calc-info-10\" data-number inputmode=\"decimal\" autocomplete=\"off\" spellcheck=\"false\" placeholder=\"e.g. 0.05\" min=\"0\" value=\"0.05\"\/><small id=\"calc-info-10\">Raz\u00e3o entre o volume de semente no frasco da amostra e o volume de semente no frasco de controle. Costuma ser igual \u00e0 fra\u00e7\u00e3o de dilui\u00e7\u00e3o P quando \u00e9 usada a mesma \u00e1gua semeada.<\/small><\/div><\/fieldset><div class=\"buttons\"><button type=\"submit\" data-text=\"Recalcular\" id=\"calculate-button\" data-post=\"2065\">Calcular<\/button><button type=\"reset\">Redefinir<\/button><\/div><div class=\"field is-checkbox hidden!\" id=\"field-auto-calc\"><input type=\"checkbox\" id=\"auto-calc\"><label for=\"auto-calc\">Calcular automaticamente<\/label><small>Se ativado, o resultado \u00e9 atualizado automaticamente quando voc\u00ea altera qualquer valor.<\/small><\/div><div class=\"fieldset-result is-hidden\" aria-labelledby=\"result-title\" aria-live=\"polite\" role=\"region\"> <h3 class=\"result-title bg-gradient-to-r from-primary-50 to-gray-50 dark:from-primary-900 dark:to-gray-800\" id=\"result-title\"><span class=\"icon icon-s-pulse\" aria-hidden=\"true\"><\/span> Seus resultados<\/h3><div class=\"result-box\"><div class=\"field-result\" id=\"output-1\"><span class=\"field-title\"><span>DBO\u2085<\/span><span class=\"result-term\">DBO\u2085<\/span><\/span><span class=\"field-value\" id=\"result-1\" data-unit=\"mg\/L\"><\/span><button type=\"button\" class=\"copy-result\" data-tooltip=\"Copiar resultado\" aria-label=\"Copiar resultado\"><span class=\"copy-icon icon icon-document-copy\" aria-hidden=\"true\"><\/span><\/button><\/div><div class=\"field-result is-column\" id=\"output-2\"><span class=\"field-title\"><span>Detalhes do c\u00e1lculo<\/span><\/span><span class=\"field-value\" id=\"result-2\"><\/span><button type=\"button\" class=\"copy-result\" data-tooltip=\"Copiar resultado\" aria-label=\"Copiar resultado\"><span class=\"copy-icon icon icon-document-copy\" aria-hidden=\"true\"><\/span><\/button><\/div><div class=\"field-result is-column\" id=\"output-3\"><span class=\"field-title\"><span>Sobre o ensaio de DBO\u2085<\/span><\/span><span class=\"field-value\" id=\"result-3\"><\/span><button type=\"button\" class=\"copy-result\" data-tooltip=\"Copiar resultado\" aria-label=\"Copiar resultado\"><span class=\"copy-icon icon icon-document-copy\" aria-hidden=\"true\"><\/span><\/button><\/div><\/div><div class=\"result-actions\"><button type=\"button\" class=\"copy-link\"><svg viewBox=\"0 0 20 20\" fill=\"currentColor\" aria-hidden=\"true\"><path d=\"M12.232 4.232a2.5 2.5 0 0 1 3.536 3.536l-1.225 1.224a.75.75 0 0 0 1.061 1.06l1.224-1.224a4 4 0 0 0-5.656-5.656l-3 3a4 4 0 0 0 .225 5.865.75.75 0 0 0 .977-1.138 2.5 2.5 0 0 1-.142-3.667l3-3Z\"\/><path d=\"M11.603 7.963a.75.75 0 0 0-.977 1.138 2.5 2.5 0 0 1 .142 3.667l-3 3a2.5 2.5 0 0 1-3.536-3.536l1.225-1.224a.75.75 0 0 0-1.061-1.06l-1.224 1.224a4 4 0 1 0 5.656 5.656l3-3a4 4 0 0 0-.225-5.865Z\"\/><\/svg><span class=\"copy-link__text\">Copiar link para este c\u00e1lculo<\/span><\/button><span class=\"sr-only\" role=\"status\" id=\"copy-link-status\"><\/span><\/div><\/div><a href=\"#respond\" class=\"hidden transition-opacity duration-300 opacity-0 w-50 text-sm justify-center items-center gap-2 px-4 py-2 rounded bg-gray-200 text-gray-700 hover:bg-gray-300\" id=\"leave-comment\"><span class=\"icon icon-comments\" aria-hidden=\"true\"><\/span>Deixar um coment\u00e1rio<\/a><\/form><\/section><section id=\"calc-reactions\" class=\"not-prose hidden my-12 bg-gradient-to-r from-primary-50 to-gray-50 border border-indigo-100 rounded-xl px-6 py-4 shadow-sm\" data-post=\"2065\" aria-live=\"polite\" aria-labelledby=\"calc-reactions-title\"><p id=\"calc-reactions-title\" class=\"text-sm text-gray-500 text-center mb-2\">O que voc\u00ea achou deste resultado?<\/p><div role=\"group\" aria-labelledby=\"calc-reactions-title\" class=\"grid grid-cols-3 sm:flex sm:flex-row sm:justify-around gap-4 sm:items-center sm:flex-wrap\"><button type=\"button\" aria-pressed=\"false\" class=\"reaction-btn flex flex-col items-center gap-1 text-sm text-gray-700 hover:text-primary-600 cursor-pointer transition-transform hover:scale-105\" data-reaction=\"like\"><span class=\"reaction-count\" data-reaction-count=\"like\">0<\/span><span class=\"reaction text-3xl\" aria-hidden=\"true\">\ud83d\ude00 <\/span><span class=\"reaction-description font-medium\">Curti <\/span><\/button><button type=\"button\" aria-pressed=\"false\" class=\"reaction-btn flex flex-col items-center gap-1 text-sm text-gray-700 hover:text-primary-600 cursor-pointer transition-transform hover:scale-105\" data-reaction=\"helpful\"><span class=\"reaction-count\" data-reaction-count=\"helpful\">0<\/span><span class=\"reaction text-3xl\" aria-hidden=\"true\">\ud83d\udca1 <\/span><span class=\"reaction-description font-medium\">\u00datil <\/span><\/button><button type=\"button\" aria-pressed=\"false\" class=\"reaction-btn flex flex-col items-center gap-1 text-sm text-gray-700 hover:text-primary-600 cursor-pointer transition-transform hover:scale-105\" data-reaction=\"confused\"><span class=\"reaction-count\" data-reaction-count=\"confused\">0<\/span><span class=\"reaction text-3xl\" aria-hidden=\"true\">\ud83d\ude15 <\/span><span class=\"reaction-description font-medium\">Confuso <\/span><\/button><button type=\"button\" aria-pressed=\"false\" class=\"reaction-btn flex flex-col items-center gap-1 text-sm text-gray-700 hover:text-primary-600 cursor-pointer transition-transform hover:scale-105\" data-reaction=\"disappointed\"><span class=\"reaction-count\" data-reaction-count=\"disappointed\">0<\/span><span class=\"reaction text-3xl\" aria-hidden=\"true\">\ud83d\ude1e <\/span><span class=\"reaction-description font-medium\">Decepcionado <\/span><\/button><button type=\"button\" aria-pressed=\"false\" class=\"reaction-btn flex flex-col items-center gap-1 text-sm text-gray-700 hover:text-primary-600 cursor-pointer transition-transform hover:scale-105\" data-reaction=\"inaccurate\"><span class=\"reaction-count\" data-reaction-count=\"inaccurate\">0<\/span><span class=\"reaction text-3xl\" aria-hidden=\"true\">\u274c <\/span><span class=\"reaction-description font-medium\">Impreciso <\/span><\/button><\/div><div id=\"reaction-message\" class=\"hidden mt-8 rounded-md border border-primary-100 bg-white\/50 backdrop-blur-sm px-4 py-2 text-sm text-center shadow-sm\"><\/div><\/section><div class=\"calcdash-ad not-prose calcdash-ad--calc_result calcdash-ad--in-article\"><ins class=\"adsbygoogle\" style=\"display:block\" data-ad-client=\"ca-pub-1721569815777345\" data-ad-slot=\"6317458308\" data-ad-layout=\"in-article\" data-ad-format=\"fluid\"><\/ins><script>(adsbygoogle = window.adsbygoogle || []).push({});<\/script><\/div>\n<style id=\"wpcoderpro-inline-1\">.formula-box {\r\n\tborder-bottom: none !important;\r\n}<\/style><section class=\"formula-box\" aria-labelledby=\"formula-title\">\r\n\t<div id=\"formula-title\" class=\"not-prose font-display mb-4\"><span class=\"icon icon-formula\" aria-hidden=\"true\"><\/span><h2>Demanda Bioqu\u00edmica de Oxig\u00eanio (DBO\u2085)<\/h2><\/div>\r\n\t<figure class=\"not-prose formula\">\r\n\t\t<figcaption class=\"formula-title\">F\u00f3rmula<\/figcaption>\r\n\t\t<div class=\"text-base text-gray-800\" id=\"formula\">\n\\[ \\mathrm{DBO}_5 = \\frac{(D_1 - D_2) - (B_1 - B_2)\\,f}{P} \\]\n<\/div>\r\n\t<\/figure>\r\n\t<\/p>\n<p><strong>Onde:<\/strong><\/p>\n<ul>\n<li>\\(D_1\\) \u2014 oxig\u00eanio dissolvido na amostra dilu\u00edda no dia 0 (mg\/L)<\/li>\n<li>\\(D_2\\) \u2014 oxig\u00eanio dissolvido remanescente ap\u00f3s 5 dias de incuba\u00e7\u00e3o a 20 \u00b0C (mg\/L)<\/li>\n<li>\\(B_1\\) \u2014 oxig\u00eanio dissolvido no dia 0 no frasco de controle da semente (mg\/L)<\/li>\n<li>\\(B_2\\) \u2014 oxig\u00eanio dissolvido no frasco de controle da semente ap\u00f3s 5 dias (mg\/L)<\/li>\n<li>\\(f\\) \u2014 fra\u00e7\u00e3o de semente: raz\u00e3o entre o volume de semente no frasco da amostra e o volume de semente no frasco de controle<\/li>\n<li>\\(P\\) \u2014 fra\u00e7\u00e3o de dilui\u00e7\u00e3o, a parte do volume final do frasco que corresponde \u00e0 amostra original (informada como porcentagem, ex.: 5% = 0,05)<\/li>\n<\/ul>\n<p>O numerador representa o oxig\u00eanio efetivamente consumido pela mat\u00e9ria org\u00e2nica da amostra (ap\u00f3s descontar a demanda da pr\u00f3pria semente); a divis\u00e3o por \\(P\\) converte esse consumo na demanda da \u00e1gua n\u00e3o dilu\u00edda.<\/p>\n<p>\r\n<\/section>\n<style id=\"wpcoderpro-inline-2\">.calculation-box {\r\n\tborder-bottom: none !important;\r\n}<\/style><section id=\"calculation\" class=\"calculation-box\" aria-labelledby=\"calculation-title\">\r\n\t<div id=\"calculation-title\" class=\"not-prose font-display\"><span class=\"icon icon-unordered-list\" aria-hidden=\"true\"><\/span><h2>Demanda Bioqu\u00edmica de Oxig\u00eanio \u2013 Exemplo de c\u00e1lculo<\/h2><\/div>\r\n\r\n<\/p>\n<p><strong>Exemplo:<\/strong> uma amostra de esgoto \u00e9 dilu\u00edda a 5% (1 parte de amostra em 20 partes no total) com \u00e1gua de dilui\u00e7\u00e3o semeada. O frasco dilu\u00eddo apresenta \\(D_1 = 9.0\\) mg\/L no in\u00edcio e \\(D_2 = 4.2\\) mg\/L ap\u00f3s 5 dias. O oxig\u00eanio no frasco de controle da semente cai de \\(B_1 = 9.0\\) para \\(B_2 = 6.6\\) mg\/L, e a fra\u00e7\u00e3o de semente \u00e9 \\(f = 0.05\\).<\/p>\n<p>\\[ D_1 - D_2 = 9.0 - 4.2 = 4.8 \\text{ mg\/L} \\]<\/p>\n<p>\\[ (B_1 - B_2)\\,f = (9.0 - 6.6) \\times 0.05 = 0.12 \\text{ mg\/L} \\]<\/p>\n<p>\\[ \\mathrm{DBO}_5 = \\frac{4.8 - 0.12}{0.05} = \\frac{4.68}{0.05} = 93.6 \\text{ mg\/L} \\]<\/p>\n<p><strong>Resultado:<\/strong> DBO\u2085 = 93,6 mg\/L \u2014 um esgoto com polui\u00e7\u00e3o moderada, bem acima do limite de validade de 20 mg\/L do m\u00e9todo padr\u00e3o.<\/p>\n<p>\n\r\n<\/section>\n<h2>Como usar a calculadora de DBO<\/h2>\n<ol>\n<li>Informe o <strong>OD inicial (D\u2081)<\/strong> \u2014 o oxig\u00eanio dissolvido da amostra dilu\u00edda, medido logo ap\u00f3s o preparo do frasco (dia 0), em mg\/L.<\/li>\n<li>Informe o <strong>OD final ap\u00f3s 5 dias (D\u2082)<\/strong> \u2014 o oxig\u00eanio dissolvido no mesmo frasco ap\u00f3s 5 dias de incuba\u00e7\u00e3o a 20 \u00b0C, no escuro.<\/li>\n<li>Informe a <strong>fra\u00e7\u00e3o de dilui\u00e7\u00e3o (P)<\/strong> como a porcentagem do volume do frasco que corresponde \u00e0 amostra original. Uma dilui\u00e7\u00e3o de 1:20 equivale a 5%; um frasco sem dilui\u00e7\u00e3o equivale a 100%.<\/li>\n<li>Se a \u00e1gua de dilui\u00e7\u00e3o foi semeada, marque <strong>Aplicar corre\u00e7\u00e3o por semente<\/strong> e preencha o <strong>OD inicial do controle da semente (B\u2081)<\/strong>, o <strong>OD final do controle da semente (B\u2082)<\/strong> e a <strong>fra\u00e7\u00e3o de semente (f)<\/strong>. Se nenhuma semente foi usada, deixe a caixa desmarcada.<\/li>\n<li>Leia o resultado da <strong>DBO\u2085<\/strong> em mg\/L, junto com o passo a passo do c\u00e1lculo e eventuais avisos de validade do m\u00e9todo padr\u00e3o.<\/li>\n<\/ol>\n<h2>O que \u00e9 a DBO\u2085 e por que ela importa<\/h2>\n<p>A demanda bioqu\u00edmica de oxig\u00eanio de cinco dias (DBO\u2085) \u00e9 a massa de oxig\u00eanio dissolvido que microrganismos aer\u00f3bios consomem ao degradar a mat\u00e9ria org\u00e2nica de uma amostra de \u00e1gua ao longo de 5 dias a 20 \u00b0C. \u00c9 a medida mais usada da carga de polui\u00e7\u00e3o org\u00e2nica biodegrad\u00e1vel de uma \u00e1gua: quanto maior a DBO\u2085, mais oxig\u00eanio o lan\u00e7amento vai retirar do rio ou lago receptor durante a decomposi\u00e7\u00e3o.<\/p>\n<p>Como a maioria dos esgotos esgotaria todo o oxig\u00eanio de um frasco cheio muito antes do dia 5, a amostra \u00e9 dilu\u00edda com \u00e1gua de dilui\u00e7\u00e3o saturada de oxig\u00eanio. O consumo medido reflete ent\u00e3o apenas a mistura dilu\u00edda, por isso a f\u00f3rmula divide pela fra\u00e7\u00e3o de dilui\u00e7\u00e3o \\(P\\) para recuperar a demanda da \u00e1gua original, n\u00e3o dilu\u00edda.<\/p>\n<p>Quando a pr\u00f3pria amostra cont\u00e9m bact\u00e9rias em quantidade insuficiente \u2014 t\u00edpico de efluentes tratados ou res\u00edduos industriais \u2014, a \u00e1gua de dilui\u00e7\u00e3o \u00e9 <em>semeada<\/em> com microrganismos, geralmente esgoto dom\u00e9stico decantado ou um preparado comercial de semente. A semente tamb\u00e9m consome oxig\u00eanio, ent\u00e3o a demanda dela \u00e9 medida em um frasco de controle paralelo e descontada, escalada pela fra\u00e7\u00e3o de semente \\(f\\), antes da divis\u00e3o por \\(P\\).<\/p>\n<p>A DBO\u2085 \u00e9 usada rotineiramente no dimensionamento de esta\u00e7\u00f5es de tratamento e no monitoramento de conformidade, e complementa a <a href=\"https:\/\/wpcalc.com\/en\/chemistry\/chemical-oxygen-demand-calculator\/\">Demanda Qu\u00edmica de Oxig\u00eanio (DQO)<\/a>, que mede a carga oxid\u00e1vel total (biodegrad\u00e1vel e n\u00e3o biodegrad\u00e1vel) em um teste muito mais r\u00e1pido. A raz\u00e3o DBO\/DQO \u00e9 um indicador comum de qu\u00e3o trat\u00e1vel biologicamente \u00e9 um esgoto. Para a cin\u00e9tica das rea\u00e7\u00f5es microbianas envolvidas, veja tamb\u00e9m a <a href=\"https:\/\/wpcalc.com\/en\/chemistry\/michaelis-menten-calculator\/\">calculadora de Michaelis\u2013Menten<\/a>.<\/p>\n<h2>Como interpretar valores t\u00edpicos de DBO\u2085<\/h2>\n<table>\n<thead>\n<tr>\n<th>Tipo de \u00e1gua<\/th>\n<th>DBO\u2085 t\u00edpica (mg\/L)<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Rio ou c\u00f3rrego limpo<\/td>\n<td>1\u20135<\/td>\n<\/tr>\n<tr>\n<td>Rio moderadamente polu\u00eddo<\/td>\n<td>5\u201320<\/td>\n<\/tr>\n<tr>\n<td>Efluente municipal tratado<\/td>\n<td>10\u201330<\/td>\n<\/tr>\n<tr>\n<td>Esgoto dom\u00e9stico bruto<\/td>\n<td>150\u2013400<\/td>\n<\/tr>\n<tr>\n<td>Res\u00edduo industrial concentrado<\/td>\n<td>at\u00e9 v\u00e1rios milhares<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h2>Premissas, limita\u00e7\u00f5es e dicas pr\u00e1ticas<\/h2>\n<ul>\n<li><strong>Condi\u00e7\u00f5es padr\u00e3o:<\/strong> a calculadora considera incuba\u00e7\u00e3o por 5 dias a 20 \u00b1 1 \u00b0C, no escuro, conforme o m\u00e9todo padr\u00e3o APHA 5210B. A nitrifica\u00e7\u00e3o n\u00e3o \u00e9 inibida, a n\u00e3o ser que um inibidor de nitrifica\u00e7\u00e3o (TCMP) tenha sido adicionado aos frascos.<\/li>\n<li><strong>Crit\u00e9rios de validade:<\/strong> o m\u00e9todo padr\u00e3o s\u00f3 \u00e9 v\u00e1lido se o consumo de oxig\u00eanio for de pelo menos 2 mg\/L, o OD residual for de pelo menos 1 mg\/L e a DBO\u2085 resultante for de pelo menos 20 mg\/L. A calculadora sinaliza viola\u00e7\u00f5es desses crit\u00e9rios \u2014 se aparecerem, repita o teste com uma dilui\u00e7\u00e3o mais adequada.<\/li>\n<li><strong>Escolha da dilui\u00e7\u00e3o:<\/strong> busque um consumo de aproximadamente 3\u20135 mg\/L partindo de um OD inicial pr\u00f3ximo \u00e0 satura\u00e7\u00e3o (~9 mg\/L a 20 \u00b0C). Para uma amostra desconhecida, prepare v\u00e1rios frascos com dilui\u00e7\u00f5es diferentes (ex.: 1%, 2%, 5%, 10%) e use o que for v\u00e1lido.<\/li>\n<li><strong>Fra\u00e7\u00e3o de semente:<\/strong> quando a mesma \u00e1gua de dilui\u00e7\u00e3o semeada \u00e9 usada nos dois frascos, \\(f\\) normalmente equivale \u00e0 fra\u00e7\u00e3o de dilui\u00e7\u00e3o na forma decimal (ex.: 0,05 para uma dilui\u00e7\u00e3o de 5%). Ajuste-a se os volumes de semente forem diferentes.<\/li>\n<li><strong>Leituras imediatas:<\/strong> D\u2081 e B\u2081 devem ser medidos no dia 0, e n\u00e3o estimados a partir de tabelas de satura\u00e7\u00e3o, especialmente ap\u00f3s a homogeneiza\u00e7\u00e3o da amostra e o equil\u00edbrio de temperatura.<\/li>\n<li><strong>Branco da \u00e1gua de dilui\u00e7\u00e3o:<\/strong> um controle separado com a \u00e1gua de dilui\u00e7\u00e3o n\u00e3o semeada n\u00e3o deve consumir mais que 0,2 mg\/L em 5 dias; brancos mais altos contaminam todos os resultados.<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Calcule a demanda bioqu\u00edmica de oxig\u00eanio de 5 dias (DBO\u2085) de uma amostra de \u00e1gua dilu\u00edda a partir do oxig\u00eanio dissolvido inicial e final, da fra\u00e7\u00e3o de dilui\u00e7\u00e3o e da corre\u00e7\u00e3o opcional por semente, conforme o m\u00e9todo padr\u00e3o APHA 5210B.<\/p>\n","protected":false},"author":3168,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[3],"tags":[22],"class_list":["post-2065","post","type-post","status-publish","format-standard","hentry","category-quimica","tag-bioquimica"],"acf":[],"_links":{"self":[{"href":"https:\/\/wpcalc.com\/pt\/wp-json\/wp\/v2\/posts\/2065","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/wpcalc.com\/pt\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/wpcalc.com\/pt\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/wpcalc.com\/pt\/wp-json\/wp\/v2\/users\/3168"}],"replies":[{"embeddable":true,"href":"https:\/\/wpcalc.com\/pt\/wp-json\/wp\/v2\/comments?post=2065"}],"version-history":[{"count":1,"href":"https:\/\/wpcalc.com\/pt\/wp-json\/wp\/v2\/posts\/2065\/revisions"}],"predecessor-version":[{"id":2280,"href":"https:\/\/wpcalc.com\/pt\/wp-json\/wp\/v2\/posts\/2065\/revisions\/2280"}],"wp:attachment":[{"href":"https:\/\/wpcalc.com\/pt\/wp-json\/wp\/v2\/media?parent=2065"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wpcalc.com\/pt\/wp-json\/wp\/v2\/categories?post=2065"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wpcalc.com\/pt\/wp-json\/wp\/v2\/tags?post=2065"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}