Spatiotemporal Evaluation of Water Quality and Hazardous Substances in Small Coastal Streams According to Watershed Characteristics.

In this study, spatial and temporal changes of eight water quality indicators and 30 types of hazardous substances including volatile organic compounds (VOCs), semi-volatile organic compounds (SVOCs), pesticides, and inorganic matters for the small coastal streams along the West Coast of South Korea were investigated. In coastal streams with clear seasonal changes in water quality, larger watershed areas led to greater contamination by particulate matter (i.e.

Combined dual-size foam glass media filtration process with micro-flocculation for simultaneous removal of particulate and dissolved contaminants in urban road runoff.

In this study, a combined media filtration process with micro-flocculation (CMF) was developed, to simultaneously treat particulate and dissolved contaminants in urban road runoff. Dual-size foam glass media with stone and sand layers were applied and the efficiency of road runoff treatment was investigated according to filtration and micro-flocculation under various experimental conditions (stone/sand layer ratio, linear velocity, and coagulant types). Moreover, the removal efficiencies of suspended solids (SS), phosphorus, organic carbon, and heavy metals (Zn, Cu, Pb, Cd) by CMF were evaluated.

Ammonia removal from anaerobic digestion effluent of livestock waste using green alga Scenedesmus sp.

The green alga Scenedesmus was investigated for its ability to remove nitrogen from anaerobic digestion effluent possessing high ammonium content and alkalinity in addition to its growth characteristics. Nitrate and ammonium were indistinguishable as a nitrogen source when the ammonium concentration was at normal cultivation levels. Ammonium up to 100ppm NH(4)-N did not inhibit cell growth, but did decrease final cell density by up to 70% at a concentration of 200-500ppm NH(4)-N.

Growth of microalgae in diluted process water of the animal wastewater treatment plant.

The growth of microalgae was investigated using diluted process water from an animal waste treatment plant as a substrate. Batch experiments were carried out to determine the growth characteristics of three microalgae strains: Microcystis aeruginosa, Chlorella vulgaris and Euglena gracilis. The two types of process water with different dilution rates were used for the experiments.

Biological nitrogen and phosphorus removal and changes in microbial community structure in a membrane bioreactor: effect of different carbon sources.

Bacterial community structures in four sequencing anoxic/anaerobic-aerobic membrane bioreactors (SAMs) that were fed with synthetic medium composed of different organic compounds in substrate as carbon source; acetate-dominant (acetate/propionate = 4/1), propionate-dominant (acetate/propionate = 1/4), glucose-dominant (glucose/acetate = 4/1) and methanol-dominant (methanol/acetate/propionate = 6/3/1) were analyzed by respiratory quinone profile and fluorescent in situ hybridization (FISH) techniques. The SAMs were operated at controlled pH range 7-8.5 and at constant temperature 25 degrees C.

Effects of the internal recycling rate on biological nutrient removal and microbial community structure in a sequential anoxic/anaerobic membrane bioreactor.

This study investigated the effects of the internal recycling rate on nutrients removal in a sequential anoxic/anaerobic membrane bioreactor (SAM). Microbial community structure in sludge from the SAM was studied using quinone profile method. Above 98% COD, 68% nitrogen, and 55% phosphorus removal efficiencies were achieved when the internal recycling rate was 2.

Influence of nitrate feeding on carbon dioxide fixation by microalgae.

In this study, the effects of nitrate feeding on microalgal growth and associated CO2 fixation were evaluated, as a strategy to enhance carbon fixation by increasing the duration of the exponential phase of cell growth in the batch operation of a photobioreactor. Two species of green algae, Chlorella and Scenedesmus, and two species of cyanobacteria, Microcystis ichthyoblabe and Microcystis aeruginosa, were used after adaptation to a 15% (v/v) CO2 environment. In the absence of nitrate feeding, nitrate concentrations declined rapidly and soon became a limiting factor.

Analysis of microbial community structure in a biofilm on membrane surface in the submerged membrane bioreactor treating domestic wastewater on the basis of respiratory quinone profiles.

The objective of this study was to investigate the microbial community structure of the biofouling film formed on hollow-fiber membrane surfaces in the submerged membrane bioreactor (SMBR) with a nitrification-denitrification process. In this experiment, aeration was conducted intermittently (60 min off, 90 min on) cyclic anoxic and oxic conditions in the SMBR. The dominant quinone types of biofilm on the membrane surface in an intermittently aerated SMBR were ubiquinone (UQs)-8, -10, followed by menaquinones (MKs)-8(H4), -8(H2) and -7, but those of suspended microorganisms were UQ-8, UQ-10 followed by MKs-8, -9(H4) and -6.

Analysis of the differences in microbial community structures between suspended and sessile microorganisms in rivers based on quinone profile.

In this study, a quinone profiling method was applied to clarify the differences in community structure between suspended and sessile microorganisms in rivers. The compositions of microbial quinone of 6 sites for 4 rivers were analyzed. Ubiquinone (UQ)-8, UQ-10, menaquinone (MK)-7, and plastoquinone (PQ)-9 were observed in all samples of suspended and sessile microorganisms for the sites investigated.