Open AccessUse of an integrated biophysical process for the treatment of halo- and nitro- organic wastes
Author(s) -
Liron Shoshani,
Asher Brenner,
Chaim Sheindorf
Publication year - 2017
Publication title -
aims environmental science
Language(s) - English
Resource type - Journals
eISSN - 2372-0352
pISSN - 2372-0344
DOI - 10.3934/environsci.2017.4.523
Subject(s) - effluent , chemistry , wastewater , activated sludge , sewage treatment , powdered activated carbon treatment , nitrification , environmental chemistry , pulp and paper industry , dilution , total organic carbon , membrane bioreactor , extracellular polymeric substance , activated carbon , nitrogen , environmental science , environmental engineering , organic chemistry , physics , genetics , adsorption , biofilm , biology , engineering , thermodynamics , bacteria
This study assessed the use of an integrated biophysical process incorporating the addition of powdered activated carbon (PAC) to a dual-sludge biological process, in order to improve the removal of problematic contaminants from complex herbicides production wastewater. The main focus was on the removal of nitrogen compounds, total organic carbon (TOC), and halogenated organics (AOX). The dual-sludge pilot setup comprised a conventional activated sludge (CAS) system followed by a membrane bioreactor (MBR) system. The dilution ratio of raw wastewater was gradually decreased (with groundwater) from 0.8 to 0 (no dilution), and PAC was added in the last phase of the study to maintain an equilibrium concentration of 2000 mg/L. PAC addition stimulated a high and steady removal (98%) of the ammoniacal nitrogen, conforming to the sea discharge limit of 5 mg/L. However, the effluent concentrations of total nitrogen, TOC, and AOX were still above the stringent discharge limits of 20, 100 and 0.5 mg/L respectively. Furthermore, it was shown that synergistic effect of various toxic organic compounds, rather than mineral salinity, was the major cause for the acute inhibitions of nitrification and AOX removal. The study showed that the proposed process can function as an efficient treatment system for the complex wastewater typically produced in the herbicide industry, however, it is recommended that complementary physico-chemical treatment steps be added to the treatment process