Authors
Abstract
Background and Purpose: Subsurface flow wetlands are one of the successful treatment methods used for municipal and industrial wastewater treatment، and are economical in terms of energy consumption and workforce. Much research has been conducted on wetland operation output in wastewater treatment، but no enough information is available on their start-up and maintenance. The present study investigates the circumstance of starting up and implementing a wetland.
Methods and Materials: In this experimental study، two subsurface flow wetlands with a two-day detention time and two pretreatment units were built. The former was similar to Primary Settling tank with a 4-hour detention time and the latter was similar to anaerobic pond equipped a with digestion pit with a two-day detention time in a pilot scale. The wastewater (BoD5 = 250 mg/l، Tss=320 mg.l and ph=7.2) from municipal network in Sabzevar، Iran was used for irrigation; the pilot implementation and maintenance took one year.
Results: Pilot operation indicated that the principal factors in implementing subsurface flow wetland were temperature، non-penetrateability of the bed، and wastewater ingredients. However، pretreatment and bed obstruction were the limiting parameters of the wetland maintenance.
Conclusion: Pretreatment of the subsurface flow of wetlands does not yield a high output; and if anaerobic ponds equipped with digestion pits are used، the treatment output is significantly enhanced، and the wetland operation will face minimum barriers.
Keywords
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