Organic and metallic pollutants in water treatment and natural wetlands: A review

Haarstad, K; Bavor, HJ; Mæhlum, T

HERO ID

1401549

Reference Type

Journal Article

Subtype

Review

Year

2012

Language

English

PMID

22173411

HERO ID 1401549
Material Type Review
In Press No
Year 2012
Title Organic and metallic pollutants in water treatment and natural wetlands: A review
Authors Haarstad, K; Bavor, HJ; Mæhlum, T
Journal Water Science and Technology
Volume 65
Issue 1
Page Numbers 76-99
Abstract A literature review shows that more than 500 compounds occur in wetlands, and also that wetlands are suitable for removing these compounds. There are, however, obvious pitfalls for treatment wetlands, the most important being the maintenance of the hydraulic capacity and the detention time. Treatment wetlands should have an adapted design to target specific compounds. Aquatic plants and soils are suitable for wastewater treatment with a high capacity of removing nutrients and other substances through uptake, sorption and microbiological degradation. The heavy metals Cd, Cu, Fe, Ni and Pb were found to exceed limit values. The studies revealed high values of phenol and SO(4). No samples showed concentrations in sediments exceeding limit values, but fish samples showed concentrations of Hg exceeding the limit for fish sold in the European Union (EU). The main route of metal uptake in aquatic plants was through the roots in emergent and surface floating plants, whereas in submerged plants roots and leaves take part in removing heavy metals and nutrients. Submerged rooted plants have metal uptake potential from water as well as sediments, whereas rootless plants extracted metals rapidly only from water. Caution is needed about the use of SSF CWs (subsurface flow constructed wetlands) for the treatment of metal-contaminated industrial wastewater as metals are shifted to another environmental compartment, and stable redox conditions are required to ensure long-term efficiency. Mercury is one of the most toxic heavy metals and wetlands have been shown to be a source of methylmercury. Methyl Hg concentrations are typically approximately 15% of Hgt (total mercury). In wetlands polycyclic aromatic hydrocarbons (PAH), bisphenol A, BTEX, hydrocarbons including diesel range organics, glycol, dichlorodiphenyltrichloroethane (DDT), polychlorinated biphenyls (PCB), cyanide, benzene, chlorophenols and formaldehyde were found to exceed limit values. In sediments only PAH and PCB were found exceeding limit values. The pesticides found above limit values were atrazine, simazine, terbutylazine, metolachlor, mecoprop, endosulfan, chlorfenvinphos and diuron. There are few water quality limit values of these compounds, except for some well-known endocrine disrupters such as nonylphenol, phtalates, etc.
Doi 10.2166/wst.2011.831
Pmid 22173411
Wosid WOS:000299163100011
Url http://dx.doi.org/10.2166/wst.2011.831
Is Certified Translation No
Dupe Override No
Is Public Yes
Language Text English
Keyword metallic; organic; pesticide; pharmaceutical; pollutants; review; wetlands
Relationship(s)