Characterization of a Biologically Treated Wastewater from Oil Reclaiming: Recording of Low Molecular Weight Organics and Estimation of Humic Substances

Abstract

Wastewater originating from oil reclaiming (COD about 300 mg/l, TOC about 70 mg/l) which was pretreated by equalization, neutralization, adsorption to activated sludge from a publicly owned treatment work, flocculation, and flotation and finally oxidized in an activated sludge process was analyzed for humic acids and gas chromatographically detectable organic compounds. The humic acid concentration was estimated to represent about 15% of the COD. Hydrocarbons were detected in activated sludge, but no hydrocarbons were identified gas chromatographically. In the two analyzed wastewater samples ethers (mainly containing polyethoxy structures), carboxylic acids and carboxylic acid esters were found. In one sample several nitrogen compounds (amines and amides) were detected. Except for l,l'-oxybis-(2-methoxy)-ethane, which was a constituent of both samples, the organic gas chromatographically detectable compounds differed completely from sample to sample. This is obviously due to changing composition of the processed spent oils.

Wastewater-Derived Dissolved Organic Nitrogen: Analytical Methods, Characterization, and Effects—A Review

“…For example, benzothiazole has been detected in wastewater effluent at concentrations between 0.02 and 0.42 µM of N () (Ellis and Soper, 1954;Legube et al, 1987;Clark et al, 1991;Gulyas et al, 1994;Grohmann et al, 1998). Pharmaceuticals are another class of nitrogen-containing compounds that have been detected in wastewater effluent at trace concentrations.…”

Organic constituents of oil reclaiming wastewater

“…Trimethylhexanoic acid was the predominant carboxylic acid present in some samples (Table 7). This compound had also been analyzed in a biologically treated wastewater of another oil reclaiming plant (Gulyas et al, 1994a). The other four detected carboxylic acids were negligible or could not be quantified because of coelution.…”

“…In river waters, phosphoric acid tributyl ester concentrations of 10 ng/1 to up to 10 ug/1 were measured during the 1970's (Muir, 1984). Although phosphoric acid tributyl ester is biodegradable (Muir, 1984), it has also been detected in a biologically treated oil reclaiming wastewater (Gulyas et al, 1994a). Thus, oil reclaiming wastewaters can be looked at as a source for phosphoric acid tributyl ester in the aquatic environment.…”

“…But also gas chromatographically detectable substances were found, among them alcohol oligo-ethoxylates (Gulyas et al, 1994a). A further purification of the biologically treated wastewaters can be achieved by the application of advanced oxidation processes as e.g.…”

Combining activated carbon adsorption with heterogeneous photocatalytic oxidation: Lack of synergy for biologically treated greywater and tetraethylene glycol dimethyl ether

“…Additionally, a polar non-aromatic compound, tetraethylene glycol dimethyl ether (TetraEGDME; 2,5,8,11,14-pentaoxapentadecane), which is nonionic but nonetheless water-soluble due to its polarity, was tested for eventual synergy in the combination process PCO/activated carbon. TetraEGDME has been detected in municipal effluents in the μg L −1 range [21,22], and also in runoff from fields irrigated with treated wastewater [23] as well as in wastewaters of two different waste oil refineries [24,25]. The experiments with greywater concentrate and TetraEGDME model wastewater were compared by means of synergy studies with phenol.…”