Removal of Organic Micropollutants by Grainy Bentonite-Activated Carbon Adsorbent in a Fixed Bed Column

Abstract

Organic micropollutants enter effluent streams and then flow into receiving waters. The volume adversely affects aquatic biota substantially. Therefore, many efforts have been made to develop methods for their elimination. The aim of this study was the removal of organic micropollutants with different properties from WWTP (wastewater treatment plant) effluent in fixed bed columns packed with several combinations of sand, granular activated carbon (GAC), and granular clay-carbonaceous composite. Two types of bentonite-powder activated carbon-based granules (Ben-AC) were prepared within this work, with different calcination temperature. It was found that higher calcination temperature enhanced the surface porosity and adsorption potential versus studied micropollutants due to dihydroxylation resulting in higher chemical activity. Introduction of these granules in the place of GAC in a fixed bed column enhances the removal degree of micropollutants and typical water quality parameters. For example, the reduction degree of color, phosphate, and nitrate concentrations increased from 83%, 69%, and 4% to 95%, 83%, and 24% for column I and II, respectively. The concentration of carbamazepine, octylphenol, nononylphenol, and anthracene was reduced by 75%, 83%, 72%, 99% in column I, while using column II or III their removal was: 86%, 97%, 99%, 99%, respectively. Independent of the column filling, the removal of carbamazepine was the lowest (75–86%), while the highest retention was obtained for anthracene (99%). The study of column performance in the treatment of effluent in time showed that column filled with Ben-AC-400 guaranteed high removal degree in the operating time. The batch adsorption data were better described by both the Langmuir model.

Preparation, Characterization and Adsorption Potential of Grainy Halloysite-CNT Composites for Anthracene Removal from Aqueous Solution

“…Therefore, the authors produced and studied individual granules containing SWCNT and SWCNT-OH. According to the modified method previously presented in [22,27], halloysite powder was added to carbon nanotubes with a weight ratio of 96:4 or 85:15. Following this, 1% nitric acid solution containing surfactant Brij (4 g/L) was added with a solid to liquid ratio of 30 g:10 mL and mixed for 30 min.…”

“…Alternatively, as based material can also be used, other clay minerals including kaolinite, zeolite, montmorillonite [24,25] can also be used. All these clay minerals are relatively cheap, eco-friendly and nontoxic and were found to be efficient for the removal of metals, dyes, radionuclides and organic pollutants [26,27]. Another clay mineral having promising properties for adsorption is nanosized halloysite Al 2 (OH) 4 Si 2 O 5 ·nH 2 O, belonging to the kaolin group.…”

Composite membranes based on polyvinyl alcohol and lamellar solids for water decontamination

“…9 Even in drinking water in many countries, it has been detected at mg L À1 to ng L À1 concentration levels. 10 Continuous intake of DS has several adverse biochemical effects. 11 The degradation of DS in aqueous solutions has been performed using biological, physical, chemical and a combination of these methods involving microalgae, 12 multiwalled carbon nanotubes, 13 activated carbon, 14,15 activated sludge, 16,17 and membranes.…”

The Efficiency of the Removal of Naphthalene from Aqueous Solutions by Different Adsorbents

“…They also conducted the adsorption studies of the naphthalene solution on coal-based activated carbon modified by microwave induction [ 19 ]. Granular aluminum-carbon composites removed anthracene (C 14 H 10 ) with 99% efficiency [ 20 ] and powdered activated carbon adsorbed hexsachlorobenzene from soil with 90% efficiency [ 21 ]. The mixture of six PAHs was adsorbed on activated carbon, sand and mineral adsorbent [ 22 ].…”