Short communication
A novel treatment system of wastewater contaminated with copper by a moss

https://doi.org/10.1016/j.bej.2005.11.013Get rights and content

Abstract

A novel treatment system of wastewater contaminated with copper was developed by using some mosses that are demonstrably metal tolerant and accumulate heavy metals into the cells. Scopelophila cataractae could remove copper more efficiently than other mosses, i.e. Physcomitrella patens and Polytrichum formosum. One hundred milligram per liter of copper ion was removed completely for 9 d using the suspended cultivation system flowing air coupled with intermittent mechanical disruption of the protonema filaments of S. cataractae by a homogenizer.

Introduction

The development of better designed and operated wastewater treatment system is desired because the permissible legal limit concentration of toxic material in the wastewater discharged into rivers and oceans has decreased annually [1], [2]. Biological treatment has been thought to be a lower cost treatment for the removal of toxic heavy metals, i.e. mercury, cadmium, and copper, from industrial wastewater.

Some mosses are known as demonstrably metal tolerant being able to withstand high levels of heavy metals that are toxic to other species [3]. One famous group of species is the copper mosses [4], [5] and Oda and Honjyo [6] have investigated the characterization of copper, lead, and zinc in metal tolerance mosses, i.e. Atrichum undulatum, Scopelophila cataractae, and Pohlia bulbifera. They reported that copper, lead, and zinc were detected in the cells of these mosses using X-ray fluorescence method and about 20 mg g−1 of heavy metals accumulated in the cell wall. If the mosses could absorb and accumulate heavy metals, the simple treatment process could be proposed for removing heavy metals from wastewater. However, very few papers on the application of mosses for the treatment of wastewater contaminated with heavy metals have been published.

In this work, the removal method of copper by the moss was developed. The mosses, Physcomitrella patens (P. patens), Polytrichum formosum (P. formosum), and Scopelophila cataractae (S. cataractae), were used to test their abilities for removing copper in the tissue cultivation using the multiple well plates. Furthermore, the suspended cultivation system flowing air coupled with intermittent mechanical disruption of the protonema filaments of mosses by a homogenizer was attempted for the efficient removal of copper.

Section snippets

Plant materials

Three mosses, P. patens, P. formosum, and S. cataractae, were used in this study. The wild-type strain of Physcomitrella patens ssp. patens [7] was used. P. formosum and S. cataractae were collected in Kanazawa City. The protonema of P. formosum was obtained from spores using the following method. The capsules of P. formosum were soaked in 10% (v/v) sodium hypochlorite solution for 5 min, and then washed with sterile distilled water. Subsequently, they were crushed out with sterile tweezers. The

Removal of copper by using three mosses

Among the bryophytes, mosses comprise approximately 10,000 or more species [13]. For testing the removal ability of copper by moss, P. patens, P. formosum, and S. cataractae, were used. P. patens is a most extensively studied moss species at the molecular level [14]. This moss was used as a control in this study because it was not metal tolerant. Polytrichum spp. is known as a “fire moss” and withstand even in harsh conditions, which rapidly colonize the surface of ground after fire [15].

Conclusions

The treatment of copper using the mosses and the suspended cultivation system flowing air coupled with intermittent mechanical disruption was investigated experimentally. S. cataractae could remove copper rather than P. patens and P. formosum. One hundred milligram per liter copper ion was removed completely by the suspended cultivation system flowing air for 19 d. Furthermore, the intermittent mechanical disruption of the protonema filaments by a homogenizer could decrease the time required for

Acknowledgments

This work was supported in part by a Grant-in-Aid for Young Scientists (B): 17710060 from the Ministry of Education, Culture, Sports, Science and Technology of Japan.

References (17)

  • E.L. Decker et al.

    The moss bioreactor

    Curr. Opin. Plant Biol.

    (2004)
  • A.H. Scagg

    Biotechnology for Engineers

    (1988)
  • G. Schwedt

    The Essential Guide to Environmental Chemistry

    (2001)
  • J.W. Bates

    Mineral nutrition, substratum ecology, and pollution

  • D.H. Brown

    Mineral nutrition

  • K. Satake

    A “copper moss” Scopelophila cataractae and copper (1)-distribution of Scopelophila cataractae in the world

    Proc. Bryol. Soc. Jpn.

    (1990)
  • T. Oda et al.

    Characterization of copper, lead, and zinc in metal tolerant mosses, Atrichum undulatum (Hedw.) P. Beauv., Scopelophila cataractae (Mitt) Broth, and Pohlia bulbifera (Warnst) Warnst. in heavy metals pollution areas

    J. Phytogeogr. Taxon.

    (1995)
  • N.W. Ashton et al.

    The isolation and preliminary characterization of auxotrophic and analogue resistant mutants in the moss Physcomitrella patens

    Mol. Gen. Genet.

    (1977)
There are more references available in the full text version of this article.

Cited by (0)

View full text
Copyright © 2005 Elsevier B.V. All rights reserved.