Application of patent bio-rack wetland system using Phragmites sp. for domestic wastewater treatment in the presence of high total dissolved solids (TDS) and heavy metal salts

J Environ Sci Eng. 2011 Jul;53(3):281-8.

Abstract

The quality of water recourses is degrading due to improper wastewater management. The aim of this study is to examine the potential of bio-rack system for treatment of domestic wastewater in the presence of high total dissolved solids (TDS) and heavy metal salts. The bio-rack is a modified wetland system incorporated with the advantages of phytoremediation and attached growth microbial process. The bio-rack is void of the soil strata based root zone system and in lieu a support matrix is provided to enrich the micro flora. The studies indicate that, Phragmites sp. can tolerate TDS up to 9000 mg/L in the bio-rack. The heavy metal removal is a function of phytoaccumulation or phytoextraction, which can lead to morphological deformity if heavy metals exceed the saturation limit of 786 and 5760 mg/kg Cd, 854 and 9280 mg/kg Cu, 639 and 4720 mg/kg Ni, 1187 and 7516 mg/kg Zn, in shoots and roots respectively. The reduction in TDS is marginal (14%) at the highest tolerable limit whereas the heavy metal reduction is 68%, 69%, 67%, 71% for Cd, Cu, Ni and Zn respectively at the outlet of the treatment system. The sewage treatment performance of the bio-rack system for all other parameters is estimated as 75 % Chemical Oxygen Demand (COD), 86 % Biological Oxygen Demand (BOD5), 27% Total Dissolved Solids (TDS), 73% Total Suspended Solids (TSS), 9% chlorides, 70% ammonia nitrogen (NH3-N), 32% phosphate (PO4-P), 92% most probable number (MPN) and 93% total viable count (TVC) reduction.

MeSH terms

  • Ammonia / analysis
  • Biodegradation, Environmental*
  • Biological Oxygen Demand Analysis
  • Chlorides / analysis
  • Ecosystem
  • Environment
  • Metals, Heavy / analysis*
  • Metals, Heavy / isolation & purification
  • Nitrogen / analysis
  • Phosphates / analysis
  • Plant Roots
  • Plant Shoots
  • Poaceae / metabolism*
  • Salts
  • Waste Disposal, Fluid
  • Water Pollutants, Chemical / analysis*
  • Water Pollutants, Chemical / isolation & purification
  • Water Purification / methods*
  • Wetlands

Substances

  • Chlorides
  • Metals, Heavy
  • Phosphates
  • Salts
  • Water Pollutants, Chemical
  • Ammonia
  • Nitrogen