Heavy Metal Removal in a Constructed Wetland and Benefits for the Development of the Toad Bufo raddei

Abstract

Heavy metal (HM) pollution in aquatic environments is of worldwide concern because of the toxicities of HMs in animals and humans. Constructed wetlands (CWs) have successfully been used as cost-effective natural systems to remove various contaminants. However, the effects of CW on the survival of animals have not been studied in any depth. We established a CW to remove HMs from water in Baiyin City, in the upper Yellow River (YR) region, which has a highly developed mining industry. The HM removal efficiency of CW as well as its effect on the development of the toad Bufo raddei were studied. The HM removal efficiencies by the CW were in the order Cd>Pb>Zn>Cu, and the decrease of the HM concentrations in the water also caused the decrease of the HM concentrations in B. raddei toads living in the CW. The toads in the CW had larger body sizes and less oxidative stress than toads living in the YR, and no malformations were found in the toads living in the CW. These results indicate that CW systems such as that used in this study could protect amphibians from developmental problems caused by HM pollution. We recommend that CW systems are used to treat polluted water and protect amphibians.

Removal efficiency of Fe, Zn and Ni from wastewater of academic campus using hybrid constructed wetlands

“…The removal efficiencies were between 53.8-100 % for HCW1 and 48.8-100 % for HCW2, depending on the time of sampling (average removal efficiency of 80.1 % for HCW-1 and of 79.3 % for HCW2). These findings are in agreement with those of Si et al [16] Those authors reported that the average removal rate of constructed wetland was 82.9 %. There were no significant differences between HCW-1 and HCW-2 in removing Zn in wastewater (figure 3B).…”