Anaerobic treatment of high sulphate containing pharmaceutical wastewater

Abstract

<span style="font-size:11.0pt;mso-bidi-font-size: 10.0pt;font-family:" times="" new="" roman","serif";mso-fareast-font-family:"times="" roman";="" letter-spacing:-.1pt;mso-ansi-language:en-gb;mso-fareast-language:en-us;="" mso-bidi-language:ar-sa"="" lang="EN-GB">The effect of different organic loading rate (OLR) to an anaerobic reactor performance and sulphate reduction was investigated. Sulphate concentration in the feed varied from 100 to 3000 mg.L^-1 and up to 97% removal efficiency was observed at OLR 0.43 - 1.23 <span style="mso-bidi-font-weight:bold">kg COD.m^-3.d^-1. However, the removal efficiency showed some decline (to 53 – 67% removal) at OLR 1.53 – 3.73 <span style="mso-bidi-font-weight:bold">kg COD.m^-3.d^-1, probably due to high sulphate concentration in the feed during this period. At a reactor OLR of 1.86 <span style="mso-bidi-font-weight:bold">kg COD.m^-3.d^-1(HRT 4 d), the soluble COD reduction was around 70 - 75%. Nevertheless, when the OLR was increased to 2.48 - 3.73 <span style="mso-bidi-font-weight: bold">kg COD.m^-3.d^-1, the COD removal efficiency decreased to 45%. The microbial aspects of sulphate reducing bacteria (SRB) results indicated that<span style="mso-bidi-font-weight:bold"> sulfidogenic bacteria, such as <i style="mso-bidi-font-style:normal">Desulfovibrio</i>, had contributed substantially to the treatment process (around 16 – 36% when the reactor was operated at OLR 0.86 – 2.98 kg COD.m^-3.d^-1).</span></span></span></span></span></span>