Characterization of H2S removal and microbial community in landfill cover soils

Abstract

H2S is a source of odors at landfills and poses a threat to the surrounding environment and public health. In this work, compared with a usual landfill cover soil (LCS), H2S removal and biotransformation were characterized in waste biocover soil (WBS), an alternative landfill cover material. With the input of landfill gas (LFG), the gas concentrations of CH4, CO2, O2, and H2S, microbial community and activity in landfill covers changed with time. Compared with LCS, lower CH4 and H2S concentrations were detected in the WBS. The potential sulfur-oxidizing rate and sulfate-reducing rate as well as the contents of acid-volatile sulfide, SO4(2-), and total sulfur in the WBS and LCS were all increased with the input of LFG. After exposure to LFG for 35 days, the sulfur-oxidizing rate of the bottom layer of the WBS reached 82.5 μmol g dry weight (d.w.)(-1) day(-1), which was 4.3-5.4 times of that of LCS. H2S-S was mainly deposited in the soil covers, while it escaped from landfills to the atmosphere. The adsorption, absorption, and biotransformation of H2S could lead to the decrease in the pH values of landfill covers; especially, in the LCS with low pH buffer capacity, the pH value of the bottom layer dropped to below 4. Pyrosequencing of 16S ribosomal RNA (rRNA) gene showed that the known sulfur-metabolizing bacteria Ochrobactrum, Paracoccus, Comamonas, Pseudomonas, and Acinetobacter dominated in the WBS and LCS. Among them, Comamonas and Acinetobacter might play an important role in the metabolism of H2S in the WBS. These findings are helpful to understand sulfur bioconversion process in landfill covers and to develop techniques for controlling odor pollution at landfills.

Performance evaluation of an on-site biocomplex textile as an alternative daily cover in a sanitary landfill, South Korea

“…The relative abundance of all methanotrophs ranged from 30.4% to 40.4% from day 66 to day 151. Several studies have observed Acinetobacter species to dominate metabolism of hydrogen sulfide in landfills (Estrada et al, 2015; Fang et al, 2016; Xia et al, 2015). The heterotrophs Ohtaekwangia koreensis, Actinophytocola gilvus, Cellulosimicrobium marinum , and Thermanaerothrix daxensis increased until day 66, and then were stable until day 151.…”

Bio-Augmentation of S2− Oxidation for a Heavily Polluted River by a Mixed Culture Microbial Consortium

“…Therefore, it is hypothesized that Enterococcaceae may play an important role in regulating the S 2 O 3 2− disproportionation reaction, contributing to the production of S 2− . In addition, some literature studies indicated that both Comamonadaceae and Alcaligenaceae could participate in the oxidation of S 2− with increasing SO 4 2− concentration [8,19,32]. However, a further study has shown that Alcaligenaceae was also able to oxidize S 2 O 3 2− through aerobic and anaerobic [19].…”

“…The high concentration of S 2− in a heavily polluted river largely contributes to the generation and accumulation of hydrogen sulfide and insoluble metal sulfides due to the combination of S 2− and hydrogen or heavy metal ions in water bodies [7]. Hydrogen sulfide, a biologically important molecule with complex physiological functions, can cause potential inhalation hazards as well as an inhibitory effect on cellular respiration [8]. While metal sulfides such as CuS, MnS, and FeS are often suspended in the river, and further aggravate the river blackening [2].…”

Bio-Augmentation of S2- Oxidation for a Heavily Polluted River by a Mixed Culture Microbial Consortium

“…The high concentration of S 2in a heavily polluted river largely contributes to the generation and accumulation of hydrogen sul de and insoluble metal sul des due to the combination of S 2and hydrogen or heavy metal ions in water bodies (Liu et al 2015). Hydrogen sul de, a biologically important molecule with complex physiological functions, can cause potential inhalation hazard as well as the inhibitory effect on cellular respiration (Xia et al 2015). While metal sul des such as CuS, MnS and FeS are often suspend in the river, and further aggravate the river blackening (Wang et al 2014).…”