• Journal of Environmental Science International
• /
• v.10 no.2
• /
• pp.159-166
• /
• 2001

We studied the appearance and proliferation of red tide organisms from March, 1998, to February, 1999, in the Jindong Bay. There were two red tide events during investigation, and we found that the dominant species Ceratium furca in May and Gymnodinium sanguineum in September, 1998. At surface, temperature and salinity showed 18.3~19.7$^{\circ}C$ and 30.6~30.9 psu in May and 25.6~27.$0^{\circ}C$, 28.0~28.5 psu in September, respectively. When the red tide occurred, the water mass stable. Dissolved inorganic nitrogen(DIN) and dissolved inorganic phosphate(DIP) in Jindong Bay showed seasonal variability. In May, the nitrogen was a limited nutrient in which the ratio of DIN versus DIP was less than 16 (Redfield ratio), while in September phosphate. During June to September, 1998, phosphate acted as a limited nutrient due to the increased river run-off from land. In May, chlorophyll-a, dissolved oxygen(DO) and chemical oxygen demand(COD) showed higher than 20$\mu\textrm{g}$/$\ell$, 10mg/$\ell$ and 5.0mg/$\ell$, respectively. In September, they showed in turns 100$\mu\textrm{g}$/$\ell$, 10mg/$\ell$ and 10mg/$\ell$, respectively.

• Journal of Industrial and Engineering Chemistry
• /
• v.68
• /
• pp.267-273
• /
• 2018

Hydrothermal liquefaction of Chlorella vulgaris feedstock containing 80% (w/w) water was conducted in a batch reactor as a function of temperature (300, 325 and $350^{\circ}C$) and reaction times (5, 10 and 30 min). The biocrude yield, elemental composition and higher heating value obtained for various reaction conditions helped to predict the optimum conditions for maximizing energy recovery. To optimize the recovery of inorganic nutrients, we further investigated the effect of reaction conditions on the ammonium ($NH_4{^+}$), phosphate ($PO_4{^{3-}}$), nitrate ($NO_3{^-}$) and nitrite ($NO_2{^-}$) concentrations in the aqueous phase. A maximum energy recovery of 78% was obtained at $350^{\circ}C$ and 5 min, with a high energy density of 34.3 MJ/kg and lower contents of oxygen. For the recovery of inorganic nutrients, shorter reaction times achieved higher phosphorus recovery, with maximum recovery being 53% at $350^{\circ}C$ and 5 min. Our results indicate that the reaction condition of $350^{\circ}C$ for 5 min was optimal for maximizing energy recovery with improved quality, at the same time achieving a high phosphorus recovery.

• Journal of Environmental Science International
• /
• v.28 no.10
• /
• pp.813-829
• /
• 2019

We measured the amount of precipitation, stemflow, and throughfall and concentrations of nine major inorganic nutrients ($H^+$, ${NH_4}^+$, $Ca^{2+}$, $Mg^{2+}$, $K^+$, $Na^+$, $Cl^-$, ${NO_3}^-$, and ${SO_4}^{2-}$) to investigate the nutrient inputs into soil from precipitation in Pinus densiflora and Quercus mongolica stands from September 2015 to August 2016. The precipitation inputs of $H^+$, ${NH_4}^+$, $Ca^{2+}$, $Mg^{2+}$, $K^+$, $Na^+$, $Cl^-$, ${NO_3}^-$, and ${SO_4}^{2-}$ into soil were 0.170, 15.124, 42.227, 19.218, 14.050, 15.887, 22.391, 5.431, and $129.440kg{\cdot}ha^{-1}{\cdot}yr^{-1}$, respectively. The P. densiflora stemflow inputs were 0.008, 0.784, 1.652, 1.044, 0.476, 0.651, 1.509, 0.278, and $9.098kg{\cdot}ha^{-1}{\cdot}yr^{-1}$, and those for Q. mongolica were 0.008, 0.684, 2.429, 2.417, 2.941, 1.398, 2.407, 0.436, and $13.504kg{\cdot}ha^{-1}{\cdot}yr^{-1}$, respectively. The P. densiflora throughfall inputs were 0.042, 21.518, 52.207 27.694, 20.060, 24.049, 37.229, 10.241, and $153.790kg{\cdot}ha^{-1}{\cdot}yr^{-1}$, and those for Q. mongolica were 0.032, 15.068, 42.834, 21.219, 20.294, 20.237, 24.288, 5.647, and $119.134kg{\cdot}ha^{-1}{\cdot}yr^{-1}$, respectively. Of the total throughfall flux (i.e., stemflow + throughfall flux) of the nine ions for the two species, ${SO_4}^{2-}$ had the greatest total throughfall flux and $H^+$ had the lowest. The net throughfall fluxes of the ions for the two species had various correlations with the precedent dry period, rainfall intensity, rainfall amount, and pH of precipitation. The soil pH under the Q. mongolica canopy (4.88) was higher than that under the P. densiflora canopy (4.34). The difference in the soil pH between the two stands was significant (P < 0.01), but the difference in soil pH by the distance from the stems of the two species was not (P > 0.01). This study shows the enrichments of inorganic nutrients by two representative urban forests in temperate regions and the roles of urban forests during rainfall events in a year.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.31 no.3
• /
• pp.326-335
• /
• 1986

In cold water irrigation, some growth and yield were decreased by heavy application of nitrogen but in-creased by heavy application of phosphate, potassium and silicate. Among growth characters, number of spikelets per panicle and grain filling ratio were affected significantly. Cold damage in number of spikelets, spikelet sterility and degeneration of spikelet and branch could be reduced by increasing application amount of phosphate, potassium and in particular silicate. Number of spikelets per branch was closely related with number of spikelets per secondary branches. Number of abortive grains and immature grains had negative correlations with yield and could be reduced by heavy application of phosphate, potassium and silicate. Heavy nitrogen application led to high total nitrogen content and restrained the uptake of phosphate, potassium and silicate. However, adverse results were showed by heavy application of phosphate, potassium and silicate. Inorganic element contents in branches were lower than those in leaf blades, but higher than those in chaff. Branches showed little differences in inorganic element contents between heading stage and maturing stage. Inorganic element contents in branches were considered to be influenced by those in leaf blades and to affect those in chaff. Some growth characters related to source and sink, such as degeneration of branches and spike-lets, sterility ratio, ripening ratio, and yield had closer relationship with nutrient contents in branches than those in leaf blades and chaff. The results demonstrated that the rachis branch not only was a transport pathway of nutrient but also would play an important role in accumulating substances in panicles.

• Korean Journal of Soil Science and Fertilizer
• /
• v.50 no.2
• /
• pp.100-105
• /
• 2017

Various methods for assessing soil total nitrogen (TN) and inorganic N content have been developed to manage nutrient and to understand N cycle in soil. This paper address the technical procedures in arable soil samples to conduct soil sampling, sample preparation, and measuring total N and inorganic N. Among various methods for measuring soil total nitrogen contents, Kjeldahl distillation and Indophenol blue method have widely used due to reliability and economic advances. Also, two methods can analyze more samples at the same time compared with other nitrogen measuring methods. For evaluating inorganic N content, mainly in forms of nitrate-N ($NO_3{^-}-N$) and ammonium-N ($NH_4{^+}-N$), extraction with a single reagent such as 2M KCl has been employed, followed by Kjeldahl distillation or indophenol blue methods.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.50 no.2
• /
• pp.108-111
• /
• 2005

A field study was conducted to develop an economically suitable combination of organic and inorganic fertilizers for sugarcane cultivation in sandy acidic soil of a commercial sugarcane farm under Old Himalayan Piedmont Plain of Bangladesh. Results revealed that the treatment $T_4$ which received $75\%$ of Recommended fertilizers (N 120, P 35, K 100, S 25, Zn 2 kg $ha^{-1}$) + 10 Mg $ha^{-1}$ Rice mill ash + Mg $ha^{-1}$ press mud significantly produced higher sugarcane yield (72.34 Mg $ha^{-1}$) among all the treatments except $T_5$ having $100\%$ of Recommended fertilizers + 10 Mg $ha^{-1}$ Rice mill ash + 10 Mg $ha^{-1}$ press mud, which was identical. $T_4$ also gave the highest net economic benefit at Bangladesh Taka 15,920.47 per hectare from the added nutrient management. Thus, the integrated use with organic and inorganic fertilizer is highly essential for sustainable production of sugarcane in commercial farm of the region in Bangladesh, where it has been grown year after year.

• Korean Journal of Soil Science and Fertilizer
• /
• v.14 no.3
• /
• pp.130-136
• /
• 1981

Rice hull was reduced to ash by carbonization grades to illcuidate alkalinity increase and extract of inorganic nutrients in the rice hull charcoal. Alkaline reaction of water extraction was neutral at less carbonized charcoal, but much carbonized ash from 65% weight loss reached over 10 of pH value, also origin shape of rice hull was maintained until near 65% carbonized grade. Therefore, physical properties sustained good condition for seedling bed. The more charcoal carbonized to ash, the pH value and concentration of inorganic nutrient in their extracts were increased gradually. Nitric acid concentrations for neutralizing extract from charcoal were stronger in proportion to the carbonized grade but 0.1 N nitric acid solution was very reasonable to neutralize the 65% carbonized charcoal for mixing with heavy texture acidy soil(pH 5.3) of uncultivated deep horizon to transplant the tobacco seedlings. Volume ratio mixing for seedling bed is adequate at five of ash to one of acid solution. Neutralization with nitric acid solution also accelerated extraction of the inorganic nutrient in rice hull ash. Tobacco seedlings grown on bed mixed with neutralized rice hull charcoal and soil had shown better results on the agronomic measurement than alkaline ash bed, and phosphorus and cations were uptaken more amounts.

• Ocean and Polar Research
• /
• v.35 no.2
• /
• pp.85-92
• /
• 2013

The coral symbiotic algae zooxanthellae is often expelled from the host as the host coral is under physiological stress, causing the coral to turn completely white. Such coral bleaching events are occurring more frequently with the increase in the global warming, ocean acidification and increased level of anthropogenic impacts such as eutrophication. In the present study, we investigated the effects of inorganic nutrients including ammonium, nitrate, phosphate and elevated water temperature on the symbiotic zooxanthellae density in the fragment of branching coral Acropora nobilis. Zooxanthellae density in the host coral decreased 8 hrs after the experiment at a given elevated water temperature ($32^{\circ}C$, p < 0.05). In contrast, no clear coral bleaching or decrease in the symbiotic algae density was observed from the branching coral exposed to a normal water temperature of $30^{\circ}C$ and high levels of nutrients such as 20 ${\mu}M$ of $NH_4Cl$, 20 ${\mu}M$ of $NaNO_3$ and, 10 ${\mu}M$ $KH_2PO_4$. Accordingly, the data indicated high water temperature is one of the stressful factors to cause bleaching in A. nobilis, whereas the high levels of nutrients is not a factor. It is believed that the results obtained in the present study are useful as baseline information in the management of the coral reefs.

• Asian-Australasian Journal of Animal Sciences
• /
• v.23 no.1
• /
• pp.82-89
• /
• 2010

An experiment was conducted to determine the influence of dietary inorganic (copper sulfate) and organic (copper proteinate) forms of copper and energy level on performance and nutrient utilization of broiler chickens. Two hundred day-old commercial Vencobb broiler chicks were purchased and randomly distributed to 20 cages of 10 birds each. These replicates were randomly assigned to one of five treatments in a (($2{\times}2$)+1) factorial arrangement. These two factors were sources of Cu ($CuSO_{4}$ vs. Cuproteinate) and dose of Cu supplements (200 mg and 400 mg/kg dietary dry matter) and the control (no supplemental Cu). After the starter period (up to 3 weeks), from d 22 onwards another factor i.e. energy at two levels (2,900 vs. 2,920 kcal/kg diet) was introduced with the previous factorial arrangements by subdividing each replicate into two equal parts, for two energy levels, without disturbing the dose and source of Cu supplement. Cu-salt supplementation linearly increased (p<0.01) live weight (LW), live weight gain (LWG) and feed conversion ratio (FCR) at 3 weeks, whereas cumulative feed intake (CFI) was unaffected (p>0.05). LWG and FCR were higher (p<0.01) in Cu-proteinate supplemented birds compared to $CuSO_{4}$ supplementation. A linear dose response (p<0.01) of Cu was found for the performance of broiler chickens. Birds having a higher energy level in the finisher stage increased (p<0.01) LWG and FCR. Cumulative feed intake was similar (p>0.05) across the groups up to the 5th week. Cu-proteinate increased performance of broiler chickens compared to $CuSO_{4}$. Dose of supplemental Cu-salt irrespective of source showed a linear response (p<0.01) for performance. Supplementation of Cu-proteinate increased metabolizability of DM (p<0.01), NFE (p<0.05), total carbohydrate (p<0.01) and OM (p<0.01) at the starter period. Increased dose of Cu-salt linearly increased (p<0.01) metabolizability of DM, CP, CF, NFE and OM. Higher energy level in the diet improved DM (p<0.05), EE (p<0.01), NFE (p = 0.01), total carbohydrate (p<0.01) and OM (p<0.01) metabolizability. Cu-proteinate supplementation showed better nutrient utilization compared to CuSO4. Dose of Cu linearly increased DM, CP, EE, NFE, total carbohydrate and OM metabolizability. CF metabolizability was unaffected (p>0.05) among the treatments. In conclusion, dietary supplementation of Cu-salt more than the requirement may improve performance and nutrient utilization in broiler chickens even with a high energy finisher diet. Cu-proteinate showed better performance and nutrient utilization compared to $CuSO_{4}$.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.11
• /
• pp.186-195
• /
• 2016

We investigated phytoplankton and vertical inorganic nutrients at two stations around water of Ulleungdo and Dokdo in the East Sea, Korea. Nutrient addition experiments (+N, +P, +NP and +Fe) were also conducted to determine the growth response and nutrient consumption of the phytoplankton assemblage using the surface water of St. UD3 and St.50. In the field, although inorganic nutrients were low in the euphotic layer, these nutrients were increased at depths below 100 m. The total phytoplankton abundances in St. UD3 and St.50 were $4.9{\times}10^5cells\;L^{-1}$ and $1.9{\times}10^5cells\;L^{-1}$, respectively. The dominant species at St. UD3 was observed to be Raphidophyta Heterosigma akashiwo, Cryptophyta Crytomonas spp., and diatom Leptocylindrus danicus, while L. danicus and H. akashiwo including small diatom species Chaetoceros socialis were dominant at St. 50. In the nutrient addition experiments, phytoplankton growth (in vivo flourescence) in the +N and +NP treatment was 2-3 times higher than that in the +P treatment, indicating that the natural phytoplankton can respond to pulsed nutrient loading events. In addition, in vivo fluorescence in +Fe treatment was not statistically (p>0.05) different from that of the non-Fe treatments, indicating that the phytoplankton growth response in +Fe treatment was not significant. Dominant H akashiwo and L. danicus in the field showed a rapid response in nutrient additional bio-algal assay, particularly L. danicus in the +Fe treatments.