Large amounts of waste and wastewater from aquaculture have negatively impacted ecosystems. Among them, shrimp aquaculture wastewater contains large amounts of nitrogen contaminants derived from feed residues in an aerobic environment. This study isolated candidate strains from adult rockworms to treat shrimp aquaculture wastewater (SAW) in an aerobic environment. Among 87 strains isolated, 25 grew well at the same temperature as the shrimp aquaculture with excellent polymer degradation ability (>0.5 cm clear zone). Six isolates (strains AL1, AL4, AL5, AL6, LA10, and PR15) were finally selected after combining strains with excellent polymer degradation ability without antagonism. 16S rRNA sequencing analysis revealed that strains AL1, AL4, AL5, AL6, LA10, and PR15 were closely related to Bacillus paramycoides, Bacillus pumilus, Stenotrophomonas rhizophila, Bacillus paranthracis, Bacillus paranthracis, and Micrococcus luteus, respectively. When these six isolates were applied to SAW, they reached a maximum cell viability of 2.06×105 CFU mL-1. Their chemical oxygen demand (CODCr) and total nitrogen (TN) removal rates for 12 h were 51.0% and 44.6%, respectively, when the CODCr/TN ratio was approximately 10.0. Considering these removal rates achieved in this study under batch conditions, these six isolates could be used for aerobic denitrification. Consequently, these six isolates from rockworms are good candidates that can be applied to the field of aquaculture wastewater treatment.

A packed bed of volcanic rock was used as deodorizing material to remove hydrogen sulfide(H2S) from air in a laboratory-scale column, and was inoculated with Thiobacillus sp. as H2S oxidizer. The effects of volcanic rock particle size distribution on system pressure drop were examined. Various tests have been conducted to evaluate the effect of H2S inlet concentration and EBCT(Empty Bed Contact Time) on H2S elimination. The pressure drop for particles of size range from 5.6 to 10 ㎜ was 14 ㎜H2O/m at a representative gas velocity of 0.25m/s. Biofilter using scoria and Thiobacillus sp. could get the stable removal efficiencies more than 99.9% under H2S inlet concentrations in the range from 30 to 1,100ppm at a constant gas flow rate of 15.2 ℓ/min. H2S removal efficiencies greater than 99% were observed as long as EBCT was longer than 8sec at the 250ppm of H2S inlet concentration. When EBCT was reduced to 5.5 sec, H2S removal efficiency decreased by about 12 percent. The maximum H2S elimination capacity was determined to be 269g-H2S/㎥·hr.