Pilot Studies and Cost Analysis of Hybrid Powdered Activated Carbon/Ceramic Microfiltration for Controlling Pharmaceutical Compounds and Organic Matter in Water Reclamation

Abstract

This paper addresses the enhanced removal of pharmaceutical compounds (PhCs), a family of contaminants of emerging concern, and effluent organic matter (EfOM) in water reclamation by powdered activated carbon/coagulation/ceramic microfiltration (PAC/cMF). Four chemically diverse PhCs are targeted: ibuprofen (IBP), carbamazepine (CBZ), sulfamethoxazole (SMX) and atenolol (ATN). Pilot assays (100 L/(m 2 h), 10 mg Fe/L) run with PhC-spiked sand-filtered secondary effluent and 15 mg/L PAC dosed in-line or to a 15-min contactor. They showed no PAC-driven membrane fouling and +15 to +18% added removal with PAC contactor, reaching significant removals of CBZ and ATN (59%-60%), SMX (50%), colour (48%), A254 (35%) and dissolved organic carbon (DOC, 28%). Earlier long-term demo tests with the same pilot proved PAC/cMF to consistently produce highly clarified (monthly median < 0.1 NTU) and bacteria-free water, regardless of the severe variations in its intake. A detailed cost analysis points to total production costs of 0.21 €/m 3 for 50,000 m 3 /day and 20 years membrane lifespan, mainly associated to equipment/membranes replacement, capital and reagents.

Hybrid Process of Adsorption/Coagulation/Ceramic MF for Removing Pesticides in Drinking Water Treatment—Inline vs. Contact Tank PAC Dosing

“…Overall, and under the conditions tested, equivalent removals of pesticides and NOM were obtained with inline PAC dosing and to a contact tank in trial 1 using the same PAC dose, while in trial 2 a higher inline PAC dose was apparently required (50% higher in the conditions tested, though further testing with other PAC doses would be necessary to confirm it). Results from trial 1 are in agreement with those observed by Ivancev-Tumbas et al [25] for p-nitrophenol removal from tap water, whereas results from trial 2 are more in agreement with our previous study [24], where PAC dosing to a contact tank yielded an added +15% to +18% pharmaceuticals' removal from a secondary effluent. The tested pesticides are small, neutral (except bentazone) molecules, diffusing into the carbon pores faster than larger NOM molecules.…”

“…These results point out that, under the tested conditions, a porous cake layer (with no increased resistance and easily backwashed) was formed on top of the membrane surface either with continuous inline PAC dosing or with continuous PAC dosing to the contact tank. Although longer trials might be necessary to fully confirm it, the results are in agreement with our previous study with a PAC/FeCl 3 /ceramic MF pilot for treating a secondary effluent [24]. Moreover, our previous study with similar waters [20] showed that 6-24 mg/L PAC dosing to a contact tank did not promote membrane fouling and that treatment capacity, an indicator incorporating key aspects of process productivity and energy needs, kept constant or slightly increased with PAC dosing.…”

“…Although several authors have approached PAC dosing modes, the focus has been on single versus step or continuous PAC dosing, and the advantages/limitations of inline PAC dosing have not yet been sufficiently studied or contradicting results were reported. For instance, our previous work [24] with pilot-scale PAC/coagulation/ceramic MF for removing four pharmaceutical compounds from a secondary effluent showed +15% to +18% added removal with a PAC contact tank compared to inline PAC dosing. In turn, pilot-scale PAC/ultrafiltration studies carried out by Ivancev-Tumbas et al [25] for removing p-nitrophenol from tap water revealed no significant differences between these two options when a continuous PAC dosing was used.…”

Carbamazepine and Diclofenac Removal Double Treatment: Oxidation and Adsorption

“…Other research based on the combination of various treatments for the reduction of CBZ were based mainly on the combined treatments of AC with membranes: PAC/MBR [ 134 ], MBR/PAC [ 135 ], and PAC/MF [ 136 ]. In these studies, reductions between 10% and 20% were obtained depending on the treatment and which membranes were used.…”

A study of inline chemical coagulation/precipitation-ceramic microfiltration and nanofiltration for reverse osmosis concentrate minimization and reuse in the textile industry

“…A summary of expenditures is given in Table 5. For CMF, the operational, specific, and maintenance costs were adapted from the TECHNEAU Report Heijman & Bakker (2007), a recent study conducted by Weschenfelder et al (2016), Viegas et al (2020), and NF costs adapted from Zhou et al (2015). The costs of mixing and pumping energy requirements corresponding to 0.026 kWh/m 3 for the CP-CMF process were included (Tompkins et al 2019), in a recent work with ceramic MF membrane energy consumption was given as 0.4 kWh/m 3 (Hakami et al 2020) in our study it was calculated as 0.15 kWh.…”