Removal of Organic Matter and Etodolac from Pharmaceutical Industry Wastewater by PAC Adsorption

Abstract

The removal of organic matter and etodolac (an anti-inflammatory pharmaceutical) from a real process wastewater by using powdered activated carbon (PAC) adsorption before and after Fenton oxidation has been studied. The wastewater sample is collected from the final stage of chemical synthesis of a pharmaceutical (etodolac). Fenton oxidation resulted with decrease in chemical oxygen demand (84% removal) and etodolac concentration was reduced to 0.7 mg L-1. Optimum adsorption equilibrium conditions were found as t = 16 hours, and m = 10 g L-1. The Freundlich model showed the best fit for the adsorption of both wastewater with R2 values of 0.89 and 0.99. Lower pseudo-second-order rate constant (k2) (0.067 < 2.62) obtained from the adsorption of raw wastewater with higher organic matter concentration confirms the chemisorption of the adsorbates onto the PAC. Pore surface mass diffusion with R2 value of 0.92 was found as rate-controlling step for adsorption process with Fenton pre-treated wastewater.

Simultaneous removal of mixed pesticides and natural organic matter from surface waters by nitric and chlorosulfonic acid functionalized powdered activated carbon

“…However, as it approaches 0, the adsorption process more resembles multilayer adsorption, which represents a very heterogeneous surface. Moreover, it indicates that the adsorption is irreversible if the value is 1 and unfavorable if it is >1 37,74‐76 . The fact that < 1 in all selected adsorbents indicated that the adsorption process took place chemically and possible irreversible 77 .…”

“…Moreover, it indicates that the adsorption is irreversible if the 1=n value is 1 and unfavorable if it is >1. 37,[74][75][76] The fact that 1=n < 1 in all selected adsorbents indicated that the adsorption process took place chemically and possible irreversible. 77 While HNO 3 modification decreased the 1=n value, ClSO 3 H modification increased it.…”

“…Similar results have been reported in the literature, showing that NOM removal by PAC using the Freundlich isotherm follows irreversible and chemical adsorption. 37,75,78,79 Removal performances of pesticides and NOM by original and acid modified adsorbents Removal studies were carried out at different adsorbent doses (1, 2, 4, 6, 8, 10, 25, 50 and 100 mg L −1 ) of original and acidmodified ACs using water samples collected from coagulation process influent stream. Table 6 presents the removal performances of the pesticides alachlor, acetochlor, metolachlor and fenthion (concentrations 66.0, 67.0, 7.8 and 302.7 μg L −1 , respectively) by the tested adsorbents.…”

Impact of Natural Organic Matter Competition on the Adsorptive Removal of Acetochlor and Metolachlor from Low-Specific UV Absorbance Surface Waters

“…1/ n , a measure of adsorption density or surface heterogeneity, is the slope of the modified isotherm plot and ranges from 0 to 1; the closer the value to 0, the greater the heterogeneity . The values of 1/ n , obtained from the modified Freundlich isotherm for acetochlor- and metolachlor-containing water samples, vary from 0.70 to 0.76 and from 0.72 to 0.79, respectively, indicating that the adsorption of organic matter by all tested activated carbons was favorable and suggested an irreversible chemisorption process (1/ n < 1) as reported in the study of adsorption of organic matter by powdered activated carbon by many researchers. ,− …”

Assessment of an aerobic granular sludge system in the presence of pharmaceutically active compounds by quantitative image analysis and chemometric techniques

“…Indeed, E2, EE2, and SMX, have already received wide attention due to several ecosystem and human health impacts that their presence in the environment pose Leal et al, 2020b. The presence of such compounds in surface waters can be partially explained by their inefficient removal in full scale WWTP including conventional activated sludge (CAS) (Joss et al, 2006). In fact, the concentrations of several PhAC usually found in aquatic environments range from ng L − 1 to μg L − 1 (Ebele et al, 2017), being also found in quite toxic concentrations in pharmaceutical industry wastewaters in a higher mg L − 1 range (Sanderson et al, 2004;Vergili and Sezin, 2017). Thus, this entire range of concentrations could be considered as environmentally relevant (Weltje and Sumpter, 2017).…”