• Journal of Korean Society of Environmental Engineers
• /
• v.35 no.8
• /
• pp.607-612
• /
• 2013

Soil ecological risk assessment requires terrestrial toxicity data based on trophic levels including plants, earthworms, nematodes, and springtails. To expand the trophic levels, it is needed to consider primary producer algae, nearly distributed in terrestrial environment, as representative terrestrial test species. In this study, we collected research cases focused on soil-related test species and exposure media from SCI papers, and analyzed exposure media, test species, test chemicals, and other test methods, for reviewing research trends of soil-related algal toxicity. Up to now, in the soil-related algal toxicity, test species were 8 cases (Pseudokirchneriella subcapitata, Chlorella vulgaris, Scenedesmus bijugatus, Chlorococcum infusionum, Scenedesmus subspicatus, Nostoc linckia, Synechococcus elongatus, and Chlorococcum sp.) and endpoints were cell count or photosynthetic pigment content. Also, 5 of exposure media were liquid medium, soil extracts, porewater, agar medium, and soil. Most of papers used algae isolated from natural soils or soil extracts. There were only one case for assessing algal toxicity in soil medium. More researches regarding algal toxicity in soil environments need to be conducted consistently.

• Korean Journal of Soil Science and Fertilizer
• /
• v.19 no.1
• /
• pp.70-75
• /
• 1986

The population and kinds of algae causing the waterbloom on the rice seedling bed and the damage of young rice plant by the nuisance green phytoplanktonic algae in rice field were studied to find out the efficiency of fertilizers and the effect of methods of fertilizers application in the rice field, laboratory, pot and green house. pot and green house. The results obtained were summarized as follows; 1. In the rice seedling bed, the kinds of algae causing waterblooms were identified mainly photosynthetic bluegreen algae as the Anabaena, Ulothrix and Oscillatoria spp. in reclaimed saline soil. Micromonospora, Oscillatoria, and Chlamydomonas spp. were habitated mainly in plain. Whereas, Spyrogyra, Oscillatoria and Navicula spp. were identified mainly in mauntainous area. 2. In the rice field, the nuisance phytoplanktonic green algae were identified mainly Scenedesmus, Chlamidospora, and Micromonospora spp. in Gimjae plain, in Namweon mountainous area and Gangjin costal plain, respectively. 3. The algal biomass has been havily habitated in which rice field were constituted with high pH value and high concentration of $NH^+_4-N$ and $NO^-_3-N$ in surface water and in soil with the optimum temperature for the algal growth ($22-30^{\circ}C$). 4. In the laboratory experiment, maximum algal biomass were obtained at levels of 80 ppm for the nitrogen and 20 ppm for the phosphorus. And were obtained of the levels of 40 ppm in the case of joint application of N and $P_2O_5$. 5. From the pot experiment, compare of the control plot, an addition of nitrogen alone or nitrogen+phosphorus enhanced algal biomass while the phosphorus alone did not. 6. Surface application of fertilizer was remarkably increased of algal biomass than did the whole layer or deep layer application.

• Journal of Environmental Impact Assessment
• /
• v.28 no.6
• /
• pp.604-615
• /
• 2019

In this study, we produce a new type of the algae soil conditioner(ASC) using discarded algae biomass through a composting process and evaluate its nutritional characteristics. As the main ingredient, the ASCs used algae biomass collected through the coagulation-floating method and made by adding a variety of additional supporting materials (sawdust, pearlite, oilcake etc.). ASCs were divided into 0% in blank, 11.7% in ASC1, 21.6% in ASC2, 37.6% in ASC3, 59.5% in ASC4, and composted during 127 days. ASCs showed a sharp increase in temperature by aerobic microbial reaction, and 6~7 high and low temperature peaks were observed. As a result of physicochemical analysis, mineralization proceeded according to decomposing the organic matter and there was a marked increase not only in macronutrients (TN, P₂O₅, K₂O), but also in secondary macronutrients (CaO, MgO). The microbial community change was found in stage 1 (bacteria, filamentous fungi) → stage 2 (actinomycetes, bacteria) → stage 3 (Bacillus sp.), depending on the maturation process. It was estimated that microbial transition was closely related to temperature change and nutritional behavior. The quality of soil conditioner can be determined according to the maturity of compost process, and it was determined that effective microbial activity could be induced by controlling algae biomass below 59.5% in this study. In conclusion, we found out the possibility of manufacturing and utilizing soil conditioner recycled algae biomass and if further technological development is made on the basis it can be used as an effective soil conditioner.

• Korean Journal of Soil Science and Fertilizer
• /
• v.42 no.spc
• /
• pp.47-50
• /
• 2009

Nutrient losses, especially nitrogen and phosphorus, in agricultural runoff can contaminate surface and ground water, leading to eutrophication. Thus, erosion control is crucial to minimizing nutrient losses from agricultural land. Assessments of various erosion control practices were carried out under various cropping system, soil management practices, and slope conditions by means of a lysimeter study and under artificial rainfall. Soil and nutrient losses were monitored in a small agricultural field to evaluate the soil conservation practices. Nutrient losses occur in runoff and leachate (dissolved nutrient) and in sediments (particulate nutrient). Dissolved nitrates accounted for the majority (about 90%) of nitrate transport within the soil. Particulate phosphate in sediments represented the majority (60% to 67%) of phosphate transport. Recently, engineering and agronomic erosion-control practices haver been used to reduce erosion problems in fields on slopes. These practices reduced soil loss, runoff, and nutrient loss to 1/6, 1/2,and 1/3 their original levels, respectively. Bioavailable particulate phosphate in sediments represents a variable but longterm source of phosphate for algae. Dissolved nitrate and phosphate are immediately available for algal uptake, so reducing fluxes of these nutrients should also reduce the risk of eutrophication.

• Korean Journal of Soil Science and Fertilizer
• /
• v.19 no.2
• /
• pp.153-156
• /
• 1986

A pot (1/200a) experiment was conducted to find out the changes of soil and water temperature on the several paddy soil weeds (Duck weed, Algae and Floatin fern) growing condition. The results obtained were shown as follows; 1. Diurnal maximum soil and water temperature were lowered by 2 to $3^{\circ}C$ under duck weed growing condition while minimum soil and water temperature were higher in $0.5^{\circ}C$ and/or similar tendency than that of bare paddy soil condition. 2. The changes of soil and water temperature were lowered by 0.1 to $0.3^{\circ}C$ at sunny day under Duck weed growing condition but was higher in 0.1 ta $0.4^{\circ}C$ at rainy, cloudy and after rainy day than that of bare paddy soil. 3. Soil and water temperature were higher about 0.3 to $1.0^{\circ}C$ under algae growing condition than that of bare paddy condition. 4. The effects of keeping warm efficiency were high in order of Duck weed > Duck weed with algae > algae > bare paddy soil condition.

• Journal of Soil and Groundwater Environment
• /
• v.20 no.7
• /
• pp.121-134
• /
• 2015

Spatial and temporal changes in algal population in Yongdam reservoir and ecological factors that induced the changes in the size and composition of algal population were investigated by monthly sampling at ten locations in the reservoir. Nutritional state of the reservoir was identified to be phosphorus-limited with nitrogen to phosphorus (N : P) ratio much greater than 17 in most samples. Algal population was dominated by three taxonomic groups, diatoms, chlorophytes and cyanobacteria. Although explosive algal growth was not observed in the summer, algal population showed transition with time of the dominant algal type from diatoms in the winter to cyanobacteria in the summer. Chlorophyta was not the dominant group in the reservoir although they maintained relatively stable number of cells in the reservoir and showed increase in population from March to May. The application of statistical methods revealed that the factors inducing changes in cell number of each group were water temperature for diatoms and cyanobacteria and phosphorus concentration for chlorophyte. Fluctuation of cyanobacterial population was mainly observed near the inlet of tributaries while diatoms showed higher variation inside the reservoir.

• Korean Journal of Soil Science and Fertilizer
• /
• v.27 no.2
• /
• pp.111-116
• /
• 1994

These studies were carried out to investigate the possibility on the agricultural utilization of lake sediment collected in the Daecheong Lake. Several parameters to estimate the degree of maturity of compost by windrow system were tested during a 50 day periods, and the results were as follows : During the composting of Daecheong Lake sediment, C/N ratio decreased gradually from 18.9 at the beginning to 13.1 at the final, while CEC increased from 33.5me/100g to 62.5me/100g. The temperature of lake sediment pile was the highest as $52^{\circ}C$ at 15th day and then decreased slowly until $30^{\circ}C{\sim}40^{\circ}C$ after 50 days. The results may be suggested that Daecheong Lake sediment compost reaches an acceptable level of stability after about 50 days. In order to know the effect of the Lake sediment and its compost on the growth of tomato(Lycopersicum esculentum M.), pot experiments were performed. The appiication of lake sediment(AS) itself, sediment organic fertilizer(SOF), and NPK mixed with sediment organic fertilizer(NSF) was more effective for tomato plant height, fresh and dry weight, and chlorphyll content than those of control treatment. Also, the lake sediment compost improved the physico-chemical properties of soil such as pH, total carbon, total nitrogen, available phosphorous and CEC.

• Proceedings of the Korean Environmental Sciences Society Conference
• /
• 2018.10a
• /
• pp.209-209
• /
• 2018

• Korean Journal of Soil Science and Fertilizer
• /
• v.9 no.4
• /
• pp.257-260
• /
• 1976

Corn (Zea may L.) and Algae (Botridium sp.) were grown in the nutrient solution to investestigate the effects of humic substances on the moderation of high salt toxicity. The results are as follows: 1) The addition of small amount of humic substances (5 ppm C) drastically decreased the high salt toxicity of corn growth. 2) The addition of 20ppm humic substances was also decreased the high salt toxicity in algaegrowth. Different concentration of humic substances, however, did not show significant difference in algae yield.

• Journal of the Korean GEO-environmental Society
• /
• v.11 no.8
• /
• pp.65-71
• /
• 2010

In this study, we have evaluated biodegradability of diesel-oxygenates including DBM and gasoline-oxygenates having similar physio-chemical properties using indigenous aerobic microorganisms from a diesel-contaminated soil. Toluene and Ethanol have shown higher biological activity and the first-order degradation rate constants ranged around $0.11{\sim}0.3day^{-1}$. However, MTBE, gasoline-oxygenate has shown as a limited substrate. Moreover, As increased initial concentrations of DBM and TGME, degradation rates of those were decreased relatively. As a strategy to evaluate biodegradability of DBM and TGME, reduction of diesel-oxygenates, $CO_2$ production and toxicity by algae were monitored. This results indicated possible mineralization of diesel-oxygenates, But we could predict that residual byproduct produced even though complete consumption of diesel-oxygenates were observed if algal toxicity variation considered. In conclusion, it is the first report that diesel-oxygenates including DBM could be biodegraded effectively by indigenous soil microorganisms and this result increased the possibility of bioremediation technology to apply into oil-contaminated sites.