오염 원인 물질의 해양 내 거동에 대한 파악은 환경 변화에 따른 부영양화 등 해양 수질 오염에 대한 예측 및 대응 방안 선정을 위한 전제 조건이다. 본 연구에서는 부영양화 원인 물질인 인의 해양퇴적물에서 해수로의 용출 특성을 조사하였다. 검토된 환경 조건은 pH 7-9, 온도 10-20℃, 용존 산소 농도(dissolved oxygen, DO) 0.7-7.0 mg/L 였다. 생물학적 요인을 배제한 조건에서 회분식 실험을 통해 구해진인 용출 자료는 1차 반응식으로 해석되었으며, 환경 조건의 영향은 통계학적 방법을 통해 정량화 되었다. 해양 퇴적물로부터 해수로의 인 용출은 pH와 온도가 높고 DO가 낮을수록 증가하였다. 1차 반응 평형 농도 기준으로 검토된 범위의 pH 증가, 온도 증가, DO 감소는 각각 인용출을 2-3배 증가시켰다.

Phosphorus (P) is an important structural component and plays critical roles in the process of energy transfer and signal transduction. Effect of low P on carbohydrate metabolism was investigated at the transcription level via transcriptome analysis using the rice 60K oligonucleotide DNA microarrays. Two-week-old rice seedlings were grown under a low (32 μM) or high (320 μM) P condition for two weeks and leaves from the seedlings were used for transcriptome analysis. Expression of genes involved in carbohydrate metabolic pathways (eg. glycolysis, sucrose degradation and starch synthesis and degradation) was most significantly affected under low P. Under low P, most genes involved in glycolysis were intensively down-regulated, genes of starch biosynthesis and degradation pathway were up- or down-regulated, and many genes involved in sucrose biosynthesis were intensively up-regulated. In leaves under low P, glucose and pyruvate levels decreased, but sucrose and starch levels increased. These results suggest that carbohydrate metabolism is adjusted primarily through comprehensive transcriptional modulation of genes involved in the carbohydrate metabolic super-pathway.

Available phosphorus(P2O5) in conventionally cultivated soil was more abundant in two fold than that of organically cultivated soil. Relative density of Arbuscular Mycorrhizal Fungi (AMF) was higher in organically cultivated soil, That of welsh onion cultivated soil was the highest, that of strawberry was followed and then that of pepper, respectively. Relative density of AMF was inversely proportioned to available soil phosphorus. Phosphorus content of crop and relative density of AMF were more abundant in organically cultivated crop or soil. However available soil phosphorus content was much in conventionally cultivated soil. The phosphorus contents between soil and crop were negatively correlated. The phosphorus content of crop was increased as the relative density of AMF increased. Relative density of AMF in the organically cultivated soil and phosphorus content of the crop with organic cultivation were higher than those of conventionally cultivated.

The purpose of this study is to investigate the effect of influent phosphorus concentration on the nitrogen and phosphorus removal in sequencing batch reactor(SBR) and sequencing batch biofilm reactors(SBBRs) in order to recover the enhanced biological phosphorus removal (EBPR) capacity at the sludge of the deterioration of EBPR capacity. In SBBRs, comparing to SBR, the organic removal was occurred actively at the 1st non-aeration period because of the active phosphorus release at this period. However, the variation of TOC removal according to the decrease of influent phosphorus concentration was not clearly shown both in SBR and SBBRs. In case of SBR losing EBPR capacity, the EBPR capacity was not recovered by the decrease of the influent phosphorus concentration from 7.5 mg/L to 0.9 mg/L. The nitrogen removal increased by the decrease of influent phosphorus concentration both in SBR and SBBRs.

The objectives of this study were to evaluate the effects of chemical additives on total phosphorus (TP), soluble reactive phosphorus (SRP), and total volatile fatty acids (total VFAs) in hanwoo slurry. The treatments in this study were ferrous sulfate, alum, and aluminum chloride, and applied at the rate of 0, 0.5, and 1.0 g/25 g of hanwoo slurry. All of the chemical treatments significantly lowered TP (11 to 53% of the untreated control), SRP (41 to 99.9% of the untreated control), and total VFAs (22 to 48.5% of the untreated control) by reducing hanwoo slurry pH (3.42 to 6.86). Among these chemical amendments, addition of 0.5 g ferrous sulfate, alum, and aluminum chloride to hanwoo slurry were the best results evaluated on farms with respect to reducing negative environmental impacts. In conclusion, the results of this study indicate that the use of chemical amendments should be considered in the development of best management practices (BMPs) for the hanwoo industries.

Trickling filter has been extensively studied for the domestic wastewater treatment especially for the small scale plants in rural area. The performance of the trickling filter depends on the microbial community and their activity in the biofilms on the media. Nitrification, denitrification, and phosphorus removal of the trickling filter from the wastewater depend on the activity and the amount of the specific microorganisms responsible for the metabolism. For the estimation of the performance of a trickling filter, batch nitrification experiment and fluorescence in situ hybridization (FISH) were carried out to measure the microbial activity and its distribution on the media of the trickling filter. Batch nitrification activity measurement showed that the top part of the 1st stage trickling filter had the highest nitrification activity and the maximum activity was 0.002 g NH4-N/g MLVSS․h. It is thought that higher substrate (ammonia) concentration yields more nitrifying bacteria in the biofilms. The dominant ammonia oxidizer and nitrite oxidizer in the biofilm were Nitrosomonas species and genus Nitrospira, respectively, by FISH analysis. Less denitrifiers were found than nitrifiers in the biofilm by the probe Rrp1088 which specifically binds to Rhodobacter, Rhodovulum, Roseobacter, and Paracoccus. Phosphorus accumulating bacteria were mostly found at the surface of the biofilm by probe Rc988 and PAO651 which specifically binds to Rhodocyclus group and their biomass was less than that of nitrifiers.

The goals of this study were conducted to investigate the effects of applying liquid aluminum chloride (AlCl3) to rice hulls on pH and soluble reactive P (SRP). A total of 800 broiler chicks (4 treatments × 4 replicates × 50 birds) were housed into 16 floor pens in a single house for 5 weeks. The treatments were divided into 4 groups: control, 100 g of liquid AlCl3/kg of rice hulls, 200 g of liquid AlCl3/kg of rice hulls, and 300 g of liquid AlCl3/kg of rice hulls. Liquid AlCl3 was sprayed on the rice hulls surface at a rate of 100 g, 200 g, and 300 g liquid AlCl3 per kg rice hull. pH values and SRP contents were significantly decreased (P<0.05) with the increased liquid AlCl3 levels in comparison with control. However, no significant differences in SRP contents were observed among all treatments at 3 and 4 weeks. Applying 100 g, 200 g, and 300 g liquid AlCl3 to rice hulls reduced SRP contents by 18, 25, and 52% for 5 weeks, respectively, compared with the controls. In conclusion, these results suggest that using liquid AlCl3 on rice hulls should be promising for reducing water contamination and resulted in a reduction in SRP contents, which reduced pH.

A laboratory experiment was conducted to investigate nitrogen removal from plating wastewater by a soil reactor. A combination of soil, waste oyster shell and activated sludge were used as a loading media in a soil reactor. The addition of 20% waste oyster shell and activated sludge to the soil accelerated nitrification (88.6% NH4+-N removal efficiency) and denitrification (84.3% NO3--N removal) in the soil reactor, respectively. In continuous removal, the influent NH4+-N was mostly converted to nitrate nitrogen in the nitrification soil reactor and only a small amount of NH4+-N was found in the effluent. When methanol was added as a carbon source to the denitrification soil reactor, the average removal efficiency of NO3--N significantly increased. The NO3--N removal by methanol addition in the denitrification soil reactor was mainly due to denitrification. The phosphorus was removed by the waste oyster shell media in the nitrification soil reactor. Moreover, the phosphorus removal in the denitrification soil reactor was achieved by synthesis of bacteria and the denitrification under anaerobic conditions. The approximate number of nitrifiers and denitrifiers was 3.3×105 MPN/g soil at a depth of 1～10 cm and 3.3×106 MPN/g soil at a depth of 10～20 cm, respectively, in the soil reactor mixed with a waste oyster shell media and activated sludge.

Shoot weight of Orostachys japonicus should determine its profitability. The study was done to determine the effect of phosphorus and potassium fertilization (0, 5, 10, 20 kg P2O5 or K2O /1000 m2) on its growth, morphological characters, and flowering. Night-break treatment of 2 hours at midnight were done since Aug. 25 when afterward samples were taken every 4 weeks to Nov. 16. Growth, morphological and flowering related characters were measured from each sample. Plant height, inflorescence length, number of leaves including bracts and stem diameter were increased with increased P and K levels. Leaf and bract, floret, shoot and total dry weights showed similar response to the above morphological characters although P fertilization more increased them than K fertilization. Florets were more formed with increased P and K levels but were not flowered due to the night-break treatment, meaning that P and K fertilization had little effect on anthesis of the florets formed.

The objective of this study was conducted to evaluate the effects of poultry litter amendments on pH and soluble reactive phosphorus (SRP) in poultry litter. Two laboratory studies were conducted for 42 d in Exp. 1 and for 10 d in Exp. 2, respectively. The poultry litter was treated with various amendments which included 4 g fly ash and 4 g AlCl3 (AlCl₃.6H₂O)/100 g litter in Exp. 1 and 4 g alum(Al₂(SO₄)₃.14H₂O), 8 g alum, 8.66 g liquid alum, and 17.3 g liquid alum/100 g litter in Exp. 2; untreated litter served as controls. There were no differences in pH between control and T1(4 g fly ash) and SRP contents between T1(4 g fly ash) and T2(4 g AlCl₃) in Exp. 1. A significant difference in pH and SRP contents in Exp. 2 was observed among all treatments(P< 0.05). In experiment 1, T1(4 g fly ash) and T2(4 g AlCl₃) at 42 d decreased SRP in litter by 47.1% and 62.6% of that from litter alone, repectively. In experiment 2, T1(4 g alum), T2(8.66 g liquid alum), T3(8 g alum), and T4(17.3 g liquid alum) treatments at 10 days reduced SRP contents by up to 36.2%, 62.9%, 87.0%, and 83.9%, respectively, when compared with the controls. Decrease in SRP contents was chiefly associated with reduction in litter pH. These results indicate that use of various litter amendments to limit P solubility has potential and should be pursued as a means of reducing soluble reative phosphorus during short term.

This study was conducted to investigate the ratios of phosphorus release to COD uptake, phosphorus release to nitrate removal, and phosphorus uptake to phosphorus release by DNPAOs(denitrifying phosphate accumulating organisms). In case I～IV, influent 1 were fed with synthetic wastewater with influent 2 NO3--N injection to anoxic zone and the case V were fed with municipal wastewater with side stream oxic zone instead of influent 2 NO3--N injection. As a result, the ratio of phosphorus release to carbon uptake was increased in accordance with nitrate supply. The DNPAOs simultaneously took up phosphate and removed nitrate from the anoxic reactor. In case I～IV, with above 20 mg/L of sufficient NO3--N supply, phosphate was taken up excessively by the DNPAOs in anoxic condition. The large amount of both uptake and release of phosphorus occurred above 20 mg/L of nitrate supply, achieving the ratio of phosphorus uptake to phosphorus release to be 1.05. In case V, phosphate luxury uptake was not occurred in system due to 6.98 mg/L of insufficient NO3--N supply and the ratio of phosphorus uptake to phosphorus release was 0.98. Consequently, if nitrate as the electron acceptor was sufficient in anoxic zone, the ratio was found to be high.

This study was carried out to investigate the variation of organic, nitrogen and phosphorus in (AO)2 SBBR process according to the variation of operating cycle at the high TOC concentration. The operation time in anoxic (anaerobic) time to oxic time was 1:1. Three lab-scale SBBRs were fed with synthetic wastewater based on glucose as carbon source. The variation of total TOC removal was similar each other irrespective of operation time, however, the TOC concentrations in SBBRs showed a little difference according to the operating condition. In SBBR, complete nitrification was not occurred at all reactors, however, R3 showed a higher nitrification than R2. And in SBBR, the variation of operating time more affected at phosphorus removal than nitrogen removal. R2 which had the shortest time at the 1st aeration time showed the lowest phosphorus release and uptake efficacy.

The response of chickpea (Cicer arietinum L.) to dual inoculation with Rhizobium (R) and arbuscular mycorrhiza (AM), nitrogen (N) and phosphorus (P) was studied on spore abundance and colonization of AM, nodulation, growth, yield attributes and yield. In all the parameters of the crop the performance of Rhizobium inoculant alone was superior to control. Dual inoculation with Rhizobium and AM in presence of P performed the best in recording number of spore 100g-1 rhizosphere soil and root colonization, number and dry weight of nodule, dry weights of shoot and root, number of pod plant-1 , number of seed pod-1 , seed and stover yields of chickpea. The maximum seed yield of 3.33 g plant-1 was obtained by inoculating chickpea plants with Rhizobium and AM in association with P. From the view point of nodulation, growth, yield attributes and yield of chickpea, dual inoculation with Rhizobium and AM along with P was considered to be the balanced combination of nutrients for achieving the highest output from cultivation of chickpea in Shallow Red Brown Terrace Soil of Bangladesh.

This study make a comparison between the phosphorus removal performance of FNR(Ferrous Nutrient Removal) process and A/O process by the laboratory experiments. For simultaneous removal of phosphorus, iron electrolysis was combined with oxic tank. Iron precipitation reactor on the electrochemical behaviors of phosphorus in the iron bed. The phosphorus removal in FNR process was more than A/O process. Iron salts produced by iron electrolysis might help to remove COD and nitrogen. And the demanded longer SRT is the more removes the removes COD, nitrogen, and phosphorus. Also, FNR process of sludge quantity more reduce than A/O process to input cohesive agents.

The present study was carried out to investigate the P fractions of surfical sediment of Dongjin sea area. Furthermore, potential released loading of adsorbed and non-apatite inorganic phosphorus were investigated in the sediment of Dongjin sea area. The contents of phosphorus fractions of the surficial sediment in Dongjin sea area were adsorbed-P 0.06%, nonapatite inorganic-P 13.02%, apatite-P 60.22%, and residual-P 26.70%. The most abundant fraction was apatite-P, residual-P, nonapatite inorganic-P, and adsorbed-P followed it. Potential released loading of adsorbed and non-apatite inorganic phosphorus surveyed 2.6 and 597ton respectively. These results show that sediment-managing and interception from external pollution are needed for water environmental maintenance of Dongjin sea area.

The experiment was conducted at the Ban­gabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur to study the response of chickpea (Cicer arietinum L) to dual inoculation of Rhizobium and arbuscular mycorrhiza, poultry litter, nitrogen, and phosphorus on spore population and colonization, nodulation, growth, yield attributes, and yield. The performance of Rhizobium inoculant alone was superior to control in all the parameters of the crop studied. Among the treatments dual inoculation of Rhizobium and arbuscular mycorrhiza in presence of poultry litter performed best in recording number and dry weight of nodules, dry weight of shoots and roots, number of pods/plant, number of seeds/pod, and seed yields of chickpea. The highest seed yield of 3.96g/plant was obtained by inoculating chickpea plants with dual inoculation of Rhizobium and arbuscular mycorrhiza in association with poultry litter. Treatments receiving dual inoculation of Rhizobium and arbuscular mycorrhiza in presence of nitrogen and phosphorus, Rhizobium inoculant in presence of nitrogen and phosphorus, and that of arbuscular mycorrhiza in presence of nitrogen and phosphorus were similar as that of treatment receiving dual inoculation of Rhizobium and arbuscular mycorrhiza in presence of poultry litter. From the view point of nodulation, growth, yield attributes, and yields of chickpea, dual inoculation of Rhizobium inoculant and arbuscular mycorrhiza along with poultry litter was considered to be the balanced combination of nutrients for achieving the maximum output from cultivation of chickpea in Shallow Red Brown Terrace Soil of Bangladesh.

This study was carried out to get more operational characteristics of Anoxic(anaerobic)-Oxic-Anoxic-Oxic (AO)2 sequencing batch biofilm reactors (SBBRs) at the low TOC concentration. The operating time in anoxic (anaerobic) time to oxic time was 1：1. Experiments were conducted to find the effects of the aeration time distribution on the organic matters and nutrients removal. Three lab-scale reactors were fed with synthetic wastewater based on glucose as carbon source. During studies, the operation mode was fixed. The first aeration time to the second aeration time in SBBR-1 was 2：3, and those in SBBR-2 and SBBR-3 were 1：4 and 3：2, respectively. The organic removal efficiency didn't show large difference among three reactors of different aeration time distribution. However, from these study results, the optimum aeration time distribution in the first and the second aeration time for biological nutrient removal was shown as 3：2. The release of phosphorus was inhibited at the second non-aeration period because of the low TOC concentration and the nitrate produced by the nitrification at the first aeration period.

A laboratory experiment was performed to investigate phosphorus and nitrogen removal from synthetic wastewater by intermittently aerated activated sludge process packed with aluminum and silver plate. Three continuous experimental processes, i. e. an intermittently aerated activated sludge process(Run A), an intermittently aerated activated sludge process with an aluminum and silver plate packed into the reactor(Run B), and a reactor post stage(Run C) were compared. In the batch experiments, the phosphorus removal time in the reactor packed with aluminum and silver plate simultaneously was faster than that of the reactor packed with only an aluminum plate. More phosphorus was removed with an increase of NaCl concentration. The pitting corrosion of aluminum does not affect the performance of the biological treatment. The total nitrogen removal efficiency in Run B was 57% and 43.6% at the HRT of 12 and 6 hours respectively. The effluent PO4-P concentration as low as 1.0 mg/L could be obtainable through the continuous experiment in Run B at HRT of 6 hours.