Open AccessIncreased nitrous oxide emissions from intertidal soil receiving wastewater from dredging shrimp pond sediments
Author(s) -
Guangcheng Chen,
Jiahui Chen,
Danyun Ou,
N.F.Y. Tam,
Shunyang Chen,
Qinghua Zhang,
Bin Chen,
Yong Ye
Publication year - 2020
Publication title -
environmental research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.37
H-Index - 124
ISSN - 1748-9326
DOI - 10.1088/1748-9326/ab93fb
Subject(s) - wastewater , environmental science , nitrification , nitrous oxide , environmental chemistry , intertidal zone , shrimp , soil water , denitrification , flux (metallurgy) , sewage , methane , nitrogen , ecology , environmental engineering , chemistry , soil science , biology , organic chemistry
The quantities of greenhouse gas emissions and the activity of functional microbes in coastal soils receiving nutrient-rich wastewaters from mariculture activities have seldom been reported. We investigated the effects of wastewater discharge resulting from dredging shrimp pond sediment on the soil fluxes of methane (CH 4 ) and nitrous oxide (N 2 O) in intertidal areas and on the functional microorganisms and physio-chemical characteristics of soil. The temporal variations in gas fluxes and soil characteristics following wastewater discharge were also evaluated with the tidal regime on the day of discharge taken into account. The results showed that wastewater discharge immediately resulted in higher levels of ammonia (NH 4 + -N) deposited and N 2 O emissions from the soil at the discharge site than at the non-discharge site, while the CH 4 flux was not affected. The increase in N 2 O flux lasted for a longer time when the discharge was performed during a neap tide day than when it was performed during a spring tide day. Wastewater discharge also increased the abundance of ammonia-oxidizing bacterial (AOB) amoA genes and nosZ genes in soil rather than increasing the abundance of narG and nirK genes. The pattern of temporal variations between the N 2 O flux and soil NH 4 + –N content was similar to that between the flux and the AOB- amoA gene abundance, suggesting that bacterial nitrification was important for N 2 O production in soil receiving the dredging wastewater. The results suggest that the wastewater discharge impacts nitrogen metabolism processes and causes a significant N 2 O emission problem; therefore, pollutant management is essential in shrimp culturing activities to reduce greenhouse gas emissions into the atmosphere.