Effects of pentachlorophenol load on PCP, COD and NH3-N removal in lab-scale multimedia-sequencing batch biofilm reactor treating recycled paper mill wastewater

Abstract

Discharge of improperly treated paper mill wastewater can be dangerous to the environment. In this study, the effects of pentachlorophenol (PCP) load were investigated and monitored for a year using lab-scale multimedia-sequencing batch biofilm reactor for the removal of PCP, chemical oxygen demand (COD) and ammoniacal nitrogen (NH-N) from recycled paper wastewater. An 18 L reactor 3 composed of Perspex column packed with cylindrical plastic media filled with granular activated carbon (GAC; coconut shells) was used to treat real recycled paper mill effluent with initial COD range of 750-1900-1 mg l at a fixed hydraulic retention time of 24 hr. Three different PCP concentrations (5, 10 and 50 mg) were spiked in the real effluent to evaluate the reactor's performance. PCP removal efficiency decreased from 94% to 61% when PCP concentrations were increased-1-1 from 5 mg l to 50 mg l. In addition, more than 88% of COD was removed, and NH-N was completely 3 eliminated. Both COD and NH-N showed stable removal throughout the study. 3 The overall performance results confirmed that the combination of biofilm and GAC was the best configuration for wastewater treatment as this combination showed good performance efficiency and stable treatment process under stern organic load fluctuations. Therefore, this hybrid system is recommended for the treatment of pulp and paper mill effluents. Multimedia, Pentachlorophenol, Recycled paper mill wastewater, Sequencing batch biofilm reactor The present study aimed to evaluate the effect of PCP load on PCP, chemical oxygen demand and ammoniacal nitrogen removal from recycled paper mill effluent in a lab-scale MM-SBBR system.

A systematic literature review of biocarriers: Central elements for biofilm formation, organic and nutrients removal in sequencing batch biofilm reactor

“…Researchers [55,56], reported that, after treatment with the pilot GAC-SBBRR, it was almost hard to foresee 2,4-dichlorophenol (2,4-DCP) residues in the effluent. A study [54] using same biocarrier material treating pentachlorophenol (PCP) also reported good performance efficiency and stable treatment process under stern organic load fluctuations with about 61% PCP removal. Utilizing a rotating perforated tube as a biocarrier material increases DCP removal efficiency.…”

“…GAC can be re-generated from apricot shells, coconut shells, coconut husks, bamboo, walnut shells etc [53]. Most of these are commercially readily available [54]. Reports have it that, the immobilization of microflora as biofilm on GAC particles (see Fig.…”

“…To begin with, NH3-N and COD demonstrated stable removal during the entire study duration by [54] using an multimedia-sequencing batch biofilm reactor (MM-SBBR). High suspended solid and color removal efficiencies were obtained using GAC with physical adsorption as the main colour removal mechanism [53,60].…”

“…In SBBR systems, GAC is being added as a biocarrier to support the production of biofilm as AS harboring microorganisms are sustained in suspension [53,54]. The numerous benefits of using GAC as a biocarrier in SBBR systems are: long preservation of biofilm, suitable for treating poorly degradable compounds, provides les toxicant concentration in the bulk fluid due to sorption process, decreases biomass susceptibility to toxicants and successful increase of decolorization rate by increasing co-substrates concentration [58,60,62].…”