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The increasing needs of drinking water due to population growth requires seeking for new tap water sources. However, these large-scale tap water sources are oftentimes abundant with dissolved natural organic matter (NOM), such as tannic acid issue causing color in water. If not removed at the source locations beforehand, NOM would impact coagulation and flocculation unit, and/or become precursors to prompt the production of disinfectant by-products after chlorination in drinking water treatment. This study focuses on developing and testing a suite of cost-effective, scalable, adaptable, and sustainable sorption media that can be implemented near the source locations of tap water as a pretreatment option to remove color for a long-distance interbasin transfer. Within the five tested sorption media, a media recipe of Zero-valent-Iron and Perlite based Green Sorption Media (ZIPGEM) with ingredients of 85% sand, 5% clay, 6% zero-valent-iron (ZVI) and 4% perlite by volume stood out as the best option for color removal. Findings showed that ZIPGEM can maintain a color removal of ∼77% for about 14,080 min, maintaining the effluent concentration below 40 Pt-Co units given the influent condition of 175 ± 10 Pt-Co units. A recovery on the adsorption capacity of ZIPGEM was observed around 40,000 min due to synergetic effects among several different ingredients of recycled ZVI, clay, sand, and perlites. ZIPGEM can be applied to industrial wastewater treatment for dye removal as well.

Nonpoint sources pollution from agricultural crop fields and urbanized regions oftentimes have elevated concentrations of dissolved organic nitrogen (DON) in stormwater runoff, which are difficult for microbial communities to decompose. The impact of elevated DON can be circumvented through the use of green sorption media, such as Biosorption Activated Media (BAM) and Iron-Filing Green Environmental Media (IFGEM), which, as integral parts of microbial ecology, can contribute to the decomposition of DON. To compare the fate, transport, and transformation of DON in green sorption media relative to natural soil (control), a series of fixed-bed columns, which contain natural soil, BAM, and two types of IFGEM, respectively, were constructed to compare nutrient removal efficiency under three distinct stormwater influent conditions containing nitrogen and phosphorus. The interactions among six microbial species, including ammonia-oxidizing bacteria, nitrite-oxidizing bacteria, complete ammonia oxidation (comammox) bacteria, anaerobic ammonium oxidation (anammox) bacteria, dissimilatory nitrate reduction to ammonium bacteria, and iron-reducing bacteria, were further analyzed from microbial ecology perspectives to determine the DON impact on nutrient removal in BAM and IFGEM. Natural soil was only able to achieve adequate DON transformation at the influent condition of lower nutrient concentration. However, the two types of IFGEM showed satisfactory nutrient removals and achieved greater transformation of DON relative to BAM when treating stormwater in all three influent conditions.

Roadside drainage networks can result in changes to watershed hydrology and water quality. By acting as hydrological links between urban development, agricultural fields, and natural streams, roadside ditches may be modified by filling in some green sorption media to control nitrogen pollution. Biosorption activated media (BAM), one of the green sorption media, are composed of sand, tire crumb, and clay, which can remove nitrogen from stormwater and groundwater through integrated hydrological, chemophysical, and microbial processes. The fate and transport processes of interest are complicated by internal microbial processes including ammonification, nitrification, denitrification, and dissimilatory nitrate reduction to ammonium (DNRA), each of which is controlled by different microbial species in addition to some varying field conditions. In this study, BAM was tested in a suite of columns to address site-specific physical, chemical and biological concerns driven by in situ traffic compaction, carbon availability, and animal impact (such as gopher turtles, moles, and ants) all of which impose different impacts on nitrogen fate and transport processes that may be signified by changing dissolved organic nitrogen species (DONs). The traffic compaction condition resulted in the most suitable hydraulic retention time in the hydrological process, which is beneficial for the assimilation of DONs in a long-term carbon rich environment due to biofilm expansion. Denitrifiers were the most predominant microbial population and the microbial species of DNRA were the second most predominant one in all three field conditions. However, the relationship of denitrifiers and DNRA in BAM can be shifted from commensalism to competition or even inhibition after carbon addition in microbial ecology.

In this study, a rapid infiltration basin (RIB) designed as green infrastructure for co-disposal of wastewater effluent and stormwater runoff was retrofitted for sustainable groundwater recharge after nitrogen removal. For comparison of nitrogen removal efficiency via different filtration media, the RIB was divided into two sub-basins for different filtration processes. One sub-basin was filled with a native sandy soil with about 2-4% clay (Control RIB), and the other sub-basin was modified with Biosorption Activated Media (BAM) (BAM RIB), for the enhancement of microbial nitrogen removal. The two sub-basins accept an equal amount of excess reclaimed wastewater in non-storm periods, and stormwater during periodic storm events. The infiltrate in both the BAM RIB and the Control RIB eventually reaches the Upper Floridan Aquifer. The seven microbial species involved in this microbial ecology study are nitrite oxidizing bacteria (NOB), ammonia oxidizing bacteria (AOB), anaerobic oxidation of ammonium (anammox) bacteria, complete ammonia oxidizer (Comammox) bacteria, denitrifiers, dissimilatory nitrate reduction to ammonium (DNRA) and ammonia-oxidizing archaea (AOA). The population dynamics study was conducted with the aid of the quantitative polymerase chain reaction (qPCR) for the quantification of the microbial gene population in support of microbial ecology discovery. The qPCR results demonstrated the competition effect between AOA, AOB, and Comammox, the inhibition effect between NOB and DNRA with the presence of anammox, and the complementary effect due to an abundance of NOB and AOB in the microbial ecology. Although, competition between denitrifiers and DNRA was expected to impact population dynamics, both microbial species were found to be the most predominant in both control and BAM RIBs. Research findings indicate that the use of BAM RIB achieves significantly efficient nitrogen removal driven by complementary effects in the microbial ecology.