Bioremediation of arsenic (As) from mine effluent by a horizontal flow constructed wetland: A case study in largest borax reserve area in over the world, Kırka, Eskişehir

Abstract

In the present experiment, a horizontal flow constructed wetland (HFCW) planted with Typha angustifolia, was tested to bioremediation potential for arsenic from mine effluent at the field in largest borax reserve area over the world, Kırka (Eskişehir). Briefly, the objective of the present experiment was to investigate arsenic bioremediation capability of wetland system and asses the phytoremediation efficiency of T. angustifolia, selected as a donor plant in this study, with different initial arsenic concentrations. The results indicated that HFCW has capability to decreased arsenic in mine effluent from 49 µg L -1 to 21.8 µg L -1 in a period of 84 days, suggesting that HFCW can defined as a reasonable low-cost treatment tool to prevent arsenic pollution. Furthermore, arsenic level in outflow samples of HFCW was stably below 10 µg L -1 (drinking water safety limit) with an inflow range from 42.3 to 42.1 arsenic µg L -1 during the first 28 days. The results also indicated that belowground parts of T.angustifolia accumulate more arsenic from mine effluent compared to aboveground parts during experiment period. Therefore, the results suggested that belowground parts of the plant in HFCW play an important role for arsenic bioremediation from mine effluent which origin of Kırka Borax reserve area. In this respect, bioconcentration factor (BCF) for the plant which grown in HFCW was found higher than those of control group. Moreover, results of the present experiment also concluded that relatively high level of arsenic retained in the filtration media of HFCW during experiment period, indicating that filtration media which was used in HFCW can remediate arsenic from mine effluent. Consequently, the scientific insight of the present experiment can defined as present an innovative, cost effective, and easy operating method for arsenic remediation from mine effluent.