Biodegradation and attenuation of MIB and 2,4-D in drinking water biologically active sand and activated carbon filters

Abstract

Biologically acclimated sand and granular activated carbon (GAC) filter performance for trace organic contaminant control is compared under variable water quality and operational conditions.

Is In-Service Granular Activated Carbon Biologically Active? An Evaluation of Alternative Experimental Methods to Distinguish Adsorption and Biodegradation in GAC

“…Previous research sterilized GAC to inhibit biodegradation but did not evaluate whether sterilization affected adsorption. − , This study monitored the effect of three cycles of autoclaving, γ irradiation at 10–12 kGy, and continuous addition of 300 mg/L sodium azide on the adsorption of DOC, carbamazepine, geosmin, caffeine, MIB, PFOS, and PFOA for both virgin GAC and preloaded GAC. The 14 C-glucose respiration rate was measured before and after sterilization to confirm the effectiveness of the microbial inhibition (Figure S9).…”

“…Previous studies − have attempted to distinguish between adsorption and biodegradation in GAC using parallel column tests, in which a GAC column is used to assess overall contaminant removal through both adsorption and biodegradation, and the other parallel column is packed with biological nonadsorbing media or sterilized GAC to evaluate biodegradation or adsorption alone. Such previous column tests have arguably employed experimental methods that are not without potential problems.…”

“…The approach of using biological nonadsorbing media in a parallel column to estimate the extent of biodegradation in GAC may not be valid since the microbial activity and community could vary between GAC and the nonadsorbing media (e.g., anthracite or sand) due to the different media characteristics. 9 For example, Shimabuku et al 6 observed greater MIB removal in a biological sand filter than in a biological activated carbon (BAC) filter, with the biomass in the sand filter being 3 times greater than in the BAC filter. Furthermore, when studies sterilized GAC to prevent biodegradation in GAC, the sterilization methods may not have completely inhibited biological activity in the GAC.…”

Prospective application of diethylaminoethyl cellulose (DEAE-cellulose) with a high adsorption capacity toward the detoxification of 2,4-dichlorophenoxyacetic acid (2,4-D) from water

“…Due to the unavailability of an antidote to the 2,4-D poisoning and the growing risk of exposure as an environmental pollutant, it is necessary to detoxify 2,4-D from agricultural water as well as drinking water. 11,12 Several methods encompassing electrodegradation, 13 biodegradation, 14,15 photodegradation, 16 catalytic ozonation, 17 and advanced oxidation 18 are well recognized for removal of 2,4-D from water and these processes have advantages as well as disadvantages. Few studies are reported using carbon nanotubes, 19 activated carbon 20 as adsorbents to remove 2,4-D and its derivatives effectively from water.…”

Converting waste textiles into highly effective sorbent materials

“…These materials have applications in areas such as energy storage, 5,6 catalyst supports, 7,8 and ltration. 9,10 In particular for ltration, the low density and inherent hydrophobic nature of carbon substrates make them suitable to remove oil and organic solvents from wastewater. 11,12 Carbon substrates can be obtained from either synthesized or natural polymer based materials.…”