Phytotechnology and Photosynthesis - Environmental Biotechnology: Theory and Application - page 162

Table7.1 Typicalanalysisforleachatetreatmentbyreed-bedsystems

Component Inlet conc Outlet conc % reduction

Chlorobenzene 83.0 < 1.0 > 98.7

1,2-Dichlorobenzene 2.0 < 1.0 > 50

1,3-Dichlorobenzene 3.6 < 1.0 > 72

1,4-Dichlorobenzene 9.8 < 1.0 > 89

1,2,4-Trichlorobenzene 0.22 < 0.05 > 77

α -Hydrocarbons 0.11 0.037 > 66

β -Hydrocarbons 0.22 < 0.005 > 97.7

γ -Hydrocarbons 0.45 0.026 > 94

δ -Hydrocarbons 1.0 0.21 > 79

ε -Hydrocarbons 1.3 0.31 > 76

2-Chlorophenol 3.7 0.84

> 77

3,4-Chlorophenol 0.63

< 0.5 > 92

2,5-Dichlorophenol 5.0 0.56

> 88

3,4-Dichlorophenol 4.9 < 0.5 > 98.9

3,5-Dichlorophenol 0.93 < 0.5 > 94

2,3,4,6-Tetrachlorophenol 6.4 < 1.0 > 84

Pentachlorophenol 2.7 < 1.0 > 62

2,2',5,5'-Penta-PCB 0.11 < 0.05 > 54

2,2',4,4',5,5'-Hexa-PCB 0.046 < 0.025 > 45

Naphthalene 17.0 < 0.05 > 99.7

1-Methylnaphthalene 1.7 < 0.05 > 97

2-Methylnaphthalene 0.58 < 0.05 > 91

Acenaphthalene 2.2 < 0.05 > 97

Fluorene 3.0 < 0.05 > 98

Phenanthrene 2.7 < 0.05 > 98

Anthracene 0.4 < 0.05 > 87

Pyrene 0.29 < 0.05 > 82

Fluoranthene 0.5 < 0.05 > 90

Trichloroethene 1.8 < 0.05 > 97

Tetrachloroethene 3.1 0.11 > 96

Benzene 52.0 < 1.0 > 98

Toluene 1.8 < 1.0 > 44

Ethylbenzene 16.0 < 1.0 > 93

m-/p-Xylene 4.1 < 1.0 > 75

o-Xylene 3.1 < 1.0 > 67

1,2,4-Trimethylbenzene 3.1

< 1.0 > 67

Concentrations are expressed in micrograms per litre (after Kickuth).

Never-the-less, reed beds and root zone treatment techniques in general are not
immune from a range of characteristic potential operational problems, which can
act to limit the efficacy of the process. Thus, excessive water-logging, surface
run-off, poor or irregular substrate penetration and the development of preferential
drainage channels across the beds may all contribute to a lessening of the system's
performance, in varying degrees.