Efficiency of subsurface flow constructed wetland with trickling filter

Abstract

Effective wastewater purification in subsurface flow constructed wetlands must include adequate pretreatment and ensure a sufficient amount of dissolved oxygen. In a pilot-scale operation, a subsurface flow constructed wetland (CW) consisted of a primary settlement tank, a trickling filter for pretreatment and two serially assembled basins. The trickling filter was added to ensure sufficient aeration, increase purification of the wastewater and shorten the wastewater purification time. The estimated nominal flow was 0.7 m3/d. The experiments were conducted using the wastewater from the municipal sewage canal of the city of Zagreb, with utilization of three different flows: 0.72 (A), 1.44 (B) and 2.88 (C) m3/d. The efficiency of the purification process was monitored over a period of three years (TSS, BOD5, COD, NH4-N, NO2-N, PO4-P, dissolved oxygen, temperature and pH). The experimental results showed an increase in the removal efficiency with a doubling of the nominal flow from 0.7 to 1.44 m3/d, which could be related to the implementation of the trickling filter where high removal rates were achieved.

Comparison of vertical-flow constructed wetlands with and without supplementary aeration treating decentralized domestic wastewater

“…Emails: zliand@uwasa.fi, liandongzhu@gmail.com, zli@hubu.edu.cn Constructed wetland (CW) technologies are natural treatment systems filled with substrate materials like sands or gravels, and planted with vegetation [11]. They are proven to be cost-effective, low maintenance and ecofriendly systems [12], especially for the treatment of urban sewages from small communities and several kinds of industrial wastewaters [13,14]. It is well known that the treatment mechanisms in CWs are complex processes that may happen sequentially or simultaneously [15], involving microbial degradation, plant uptake, sorption, sedimentation, filtration and precipitation [16,17].…”

Biological Fixed Film

“…Based on the mass balance of glucose and the dye in a fungal biofilm and a liquid biofilm, optimal corrugation values were 0.853 and 0.59 at initial dye concentrations of 0.09433 kg m -3 and 0.05284 kg m -3 , respectively. A good agreement between the simulated and experimental results was achieved.Trickling filter as pretreatment was used for effective wastewater purification in subsurface flow constructed wetland(Vucinic et al 2012). The efficiency of the process (TSS, BOD 5 , COD, NH 4 -N, NO 2 -N, PO 4 -P, dissolved oxygen, temperature and pH) was monitored over three years.…”