Nitrification enhancement by powdered activated carbon addition in activated sludge

Thesis/Dissertation · Tue Jan 01 04:00:00 EST 1985

OSTI ID:5717801

Ng, A S

Previous investigators provided evidence that the addition of powdered activated carbon (PAC) to nitrifying activated sludge (AS) can improve nitrification rates. Plausible but unsubstantiated mechanisms proposed to explain these observations include adsorption of compounds toxic to nitrifiers; enhanced growth of nitrifiers and/or concentration of trace nutrients on the carbon surface. The major objective of this research is to further define the mechanics of nitrification enhancement in PAC-AS. Using refinery and synthetic wastewater feed, a series of acute and chronic experiments, as well as experiments with variable carbon dosages, was conducted to evaluate the relative importance of adsorption, suspended solids, and microbial acclimation on AS nitrification rates. The general procedure was to compare the effect of a spiked adsorbable/non-adsorbable, inhibitory compound on nitrification rates in AS and in AS supplemented either with PAC or inert suspended solids (bentonite clay). With spiked adsorbable inhibitors, the acute experiments demonstrated nitrification enhancement due to PAC addition in unacclimated sludge cultures. Statistically significant enhancement due to either PAC or bentonite addition was not evident in any experiment where a nonadsorbable inhibitor was added. A chronic experiment gave evidence that the addition of PAC of AS can inhibit nitrification by virtue of desorption of a previously adsorbed inhibitor. In this same experiment, it was shown that an adequate dose of virgin PAC can dramatically arrest the effect of an adsorbable inhibitor and restore full nitrification capability.

• Research Organization: California Univ., Los Angeles (USA)
• OSTI ID: 5717801
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020800* -- Petroleum-- Waste Management
ACTIVATED CARBON
ACTIVATED SLUDGE PROCESS
ADSORBENTS
ADSORPTION
CARBON
CHEMICAL REACTIONS
DESORPTION
ELEMENTS
HYDROGEN COMPOUNDS
INDUSTRIAL PLANTS
INHIBITION
KINETICS
LIQUID WASTES
MANAGEMENT
NITRIFICATION
NONMETALS
OPTIMIZATION
OXYGEN COMPOUNDS
PERFORMANCE TESTING
PETROLEUM REFINERIES
PROCESSING
REACTION KINETICS
SORPTION
TESTING
WASTE MANAGEMENT
WASTE PROCESSING
WASTE WATER
WASTES
WATER
WATER TREATMENT