Enhancing Nitrification at Low Temperature with Zeolite in a Mining Operations Retention Pond

Abstract

Ammonium nitrate explosives are used in mining operations at Diavik Diamond Mines Inc. in the Northwest Territories, Canada. Residual nitrogen is washed into the mine pit and piped to a nearby retention pond where its removal is accomplished by microbial activity prior to a final water treatment step and release into the sub-Arctic lake, Lac de Gras. Microbial removal of ammonium in the retention pond is rapid during the brief ice-free summer, but often slows under ice cover that persists up to 9 months of the year. The aluminosilicate mineral zeolite was tested as an additive to retention pond water to increase rates of ammonium removal at 4°C. Water samples were collected across the length of the retention pond monthly over a year. The structure of the microbial community (bacteria, archaea, and eukarya), as determined by denaturing gradient gel electrophoresis of PCR-amplified small subunit ribosomal RNA genes, was more stable during cold months than during July–September, when there was a marked phytoplankton bloom. Of the ammonia-oxidizing community, only bacterial amoA genes were consistently detected. Zeolite (10 g) was added to retention pond water (100 mL) amended with 5 mM ammonium and incubated at 12°C to encourage development of a nitrifying biofilm. The biofilm community was composed of different amoA phylotypes from those identified in gene clone libraries of native water samples. Zeolite biofilm was added to fresh water samples collected at different times of the year, resulting in a significant increase in laboratory measurements of potential nitrification activity at 4°C. A significant positive correlation between the amount of zeolite biofilm and potential nitrification activity was observed; rates were unaffected in incubations containing 1–20 mM ammonium. Addition of zeolite to retention ponds in cold environments could effectively increase nitrification rates year-round by concentrating active nitrifying biomass.

Cold Adapted Nitrosospira sp.: A Potential Crucial Contributor of Ammonia Oxidation in Cryosols of Permafrost-Affected Landscapes in Northeast Siberia

“…Additionally, Avrahami et al [88] found a correlation between low temperature and the occurrence of Nitrosospira. In a cold mining operation retention pond in the Northwest Territories, Canada, Nitrosospira was identified as the main AOB [89]. In addition, Hayashi et al [24] detected AOB belonging to the genus Nitrosospira in Svalbard; however, cold bioreactors treated with inorganic mine waters contained Nitrosospira together with Nitrosomonas [90].…”

Sustainable lake restoration: From challenges to solutions

“…While zeolite has poor phosphate adsorption capacity, because the cavities in this highly porous material are negatively charged, the negative charge improves their adsorption capacity for ammonium and metal ions (Lin et al, 2011; Wen et al, 2016). Zeolites may also promote nitrification (Miazga‐Rodriguez et al, 2012). Each of these methods has its own specifics that must be considered.…”

Toward More Efficient and Sustainable Autotrophic Ammonia Removal From Wastewater

“…The ability for microbial biofilms to offer protection from environmental and predatory stress has been well documented (Aqeel et al, 2019;Lee et al, 2014;Wang et al, 2018;Wucher et al, 2021;Yin et al, 2019). For example, a common method to improve the performance of nitrification systems experiencing low temperatures or high ammonia loading is to increase the retention of biofilm biomass through the addition of carrier materials with ample surface area for microbial attachment (Aqeel and Liss, 2020;Delatolla et al, 2012;Miazga-Rodriguez et al, 2012). However, it is currently unclear whether the use of fixed-films systems can also help to overcome the low pH stress brought on by depletion of the available alkalinity, or any associated inorganic carbon limitation.…”