Influence of nutrient supplementation on DOC removal in drinking water biofilters

Abstract

Analysis of the impacts of nitrogen, phosphorus and potassium supplementation on biofilter performance for organic carbon removal was studied on laboratory-scale biofilter columns. Three dual media biofilter columns were fed with synthetic raw water C:N:P ratios of 546:24:1, 100:10:1, and 25:5:1 (w/w) to simulate nutrient limited and two nutrient supplemented conditions, respectively. Research found that air-scour versus water only backwash improved the nutrient limited dissolved organic carbon (DOC) removal by 8%. In addition, nutrient supplementation and backwash alteration improved DOC removals by 19% for the 25:5:1 column and 14% for the 100:10:1 column. Potassium supplementation with the 25:5:1 C:N:P ratio column had no discernible effect on DOC removal. No correlation with phospholipid (7–474 nmol P/g media) and adenosine triphosphate (ATP) (0.6 × 105–32.74 × 105 pg ATP/g media) values with DOC removal were found. Nutrient availability was found to influence DOC removal, demonstrating its importance when utilizing biofiltration for treatment of source waters.

Biostability of Tap Water—A Qualitative Analysis of Health Risk in the Example of Groundwater Treatment (Semi-Technical Scale)

“…Literature indicates that the microbial activity correlates with the availability of nutrients, i.e., the content of carbon, nitrogen, and phosphorus in the water flowing into the biosorption field. The C:N:P ratio should be 100:10:1 and deficiency of any of the constituents limits the growth and development of microorganisms, thus interfering with the course of the biodegradation process [39,40]. Dhawan et al controlled the effectiveness of three biofilters in which the treated water differed in terms of nutrient content as follows: 546:24:1, 100:10:1, and 25:10:1.…”

“…Dhawan et al controlled the effectiveness of three biofilters in which the treated water differed in terms of nutrient content as follows: 546:24:1, 100:10:1, and 25:10:1. The Dissolved Organic Carbon (DOC) removal efficiency was 23.5%, 28.6%, and 33.5% respectively [40]. In the case of waters containing natural organic matter and inorganic nitrogen, phosphate ions are essential [41,42].…”

Effects of water quality changes on performance of biological activated carbon (BAC) filtration

“…However, in some cases it was found that microbial growth in drinking water was limited by phosphorus [18][19][20][21] or nitrogen [13] instead of carbon. Dhawan et al [22] investigated the influence of nutrient supplementation on DOC removal by BAC filters by testing different types of ratios. Increased nutrient concentrations beyond the typical ratio of 100:10:1, resulted in increased removal of DOC.…”

“…Although researchers have tried to find correlations between biomass development and the observed biodegradation in the BAC filters under varying operating conditions, no clear correlations have been found [14,22]. This underlines the complexity of the processes taking place in the BAC filters.…”

A comparative pilot scale study analyzing the performance of biological versus conventional drinking water filtration with the application of various backwash strategies for headloss and ripening control

“…According to LeChevallier et al (1999), for optimal biofiltration performance a C:N:P ratio of 39:4.5:1 on a weight basis is required. Under nutrient rich conditions, authors have reported improvement in organics removals (Dhawan, et al 2017. .…”