Environmental Science and Pollution Research

, Volume 20, Issue 3, pp 1858–1869

Application of dynamic models to estimate greenhouse gas emission by wastewater treatment plants of the pulp and paper industry

Authors

  • Omid Ashrafi
    • Department of Building, Civil & Environmental EngineeringConcordia University
  • Laleh Yerushalmi
    • Department of Building, Civil & Environmental EngineeringConcordia University
    • Department of Building, Civil & Environmental EngineeringConcordia University
Research Article

DOI: 10.1007/s11356-012-1310-5

Cite this article as:
Ashrafi, O., Yerushalmi, L. & Haghighat, F. Environ Sci Pollut Res (2013) 20: 1858. doi:10.1007/s11356-012-1310-5

Abstract

Greenhouse gas (GHG) emission in wastewater treatment plants of the pulp-and-paper industry was estimated by using a dynamic mathematical model. Significant variations were shown in the magnitude of GHG generation in response to variations in operating parameters, demonstrating the limited capacity of steady-state models in predicting the time-dependent emissions of these harmful gases. The examined treatment systems used aerobic, anaerobic, and hybrid—anaerobic/aerobic—biological processes along with chemical coagulation/flocculation, anaerobic digester, nitrification and denitrification processes, and biogas recovery. The pertinent operating parameters included the influent substrate concentration, influent flow rate, and temperature. Although the average predictions by the dynamic model were only 10 % different from those of steady-state model during 140 days of operation of the examined systems, the daily variations of GHG emissions were different up to ±30, ±19, and ±17 % in the aerobic, anaerobic, and hybrid systems, respectively. The variations of process variables caused fluctuations in energy generation from biogas recovery by ±16, ±17, and ±14 % in the three examined systems, respectively. The lowest variations were observed in the hybrid system, showing the stability of this particular process design.

Keywords

Greenhouse gasDynamic modelWastewater treatment plantsImpact of process parametersEnergy generation

Nomenclature

An

Anaerobic reactor

Bio

Biological treatment

BOD

Biochemical oxygen demand

dr

Anaerobic digester

dnt

Denitrification

eff

Effluent

fd

Biomass as a cell debris (kilograms VSS per kilogram VSS)

flocc

Coagulation/flocculation

HRT

Hydraulic retention time (day)

in

Influent

k

Maximum utilization rate (kilograms BOD per kilogram VSS per day)

kd

Decay rate (kilograms per kilogram per day)

KH

Henry's constant

Ks

Half velocity growth rate (kilograms per cubic meter)

μm

Maximum bacterial growth rate (kilograms per kilogram per day)

N

Nitrogen concentration (kilograms per cubic meter)

nb

Non-biodegradable

nit

Nitrification

P

Wasted solid or sludge (kilograms per day)

PP

Partial pressure (standard atmosphere)

Q

Flow rate (cubic meter per day)

\( {r_{{{{\mathrm{O}}_2}}}} \)

Oxygen consumption rate (kilograms per day)

rsu

Rate of substrate change due to utilization (kilograms per cubic meter per day)

rX

Biomass production rate (kilograms per cubic meter per day)

\( {r_{{\mathrm{C}{{\mathrm{O}}_2}}}} \)

Carbon dioxide consumption rate (kilograms per day)

S

BOD concentration (kilograms per cubic meter)

SRT

Solid retention time (day)

t

Time (day)

TKN

Total Kjeldahl nitrogen (kilograms per cubic meter)

VSS

Volatile suspended solid (kilograms per day)

V

Volume (cubic meter)

Y

Yield coefficient (kilograms per kilogram)

W

Waste

X

Biomass concentration (kilograms per cubic meter)

Copyright information

© Springer-Verlag Berlin Heidelberg 2012