• 한국환경과학회지
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• 제15권3호
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• pp.229-236
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• 2006

Organophosphorus pesticides (OPPs) contents in the sewage sludge derived from the residential and industrial areas were determined in order to characterize contemporary organic contamination levels as a part of the ongoing development of the environmentally sound sewage sludge management strategy in Korea. OPPs were extracted from freeze-dried sludges in a ultrasonic extractor. The extracts were cleaned-up by florisil column and subsequently fed into gas chromatograph/nitrogen phosphorus detector (GC/NPD) for determining OPP contents. Diazinon, dimethoate, disulfoton, EPN, malathion, methyl parathion, parathion, phorate and sulfotep were present in the appreciable amount in the domestic sewage sludges. The sum of the 9 OPPs in the sewage sludge varied from 534.8 to 15552.1 ${\mu}g/kg$, dry wt..

• 한국유기농업학회지
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• 제13권4호
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• pp.339-355
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• 2005

Nutrient balance is important to develop environmentally friendly agriculture. Phosphorus surplus in nutrient balance was more serious than that of nitrogen. Nitrogen and phosphorus exceeded twice the requirement at 30 cities/counties and 32 among 165, respectively. Given livestock waste and optimal nutrient balance, the proper number of animal feeding was 1.68LU/ha. Considering livestock waste only, the optimal number of livestock feeding was 3,918,000LU (heads) and, including fertilizer that would be 2,288,000LU. It is recommended to introduce the regional control system to regulate nutrient input and output, and the trading system of livestock feeding rights to control that.

• 한국환경보건학회지
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• 제39권1호
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• pp.83-89
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• 2013

Objectives: The purpose of this experiment was to illuminate the relationship between the phosphorus removal rate of unit operation and the phosphorus removal rate of phosphorus volume loading in the Ferrous Nutrient Removal process, which consists of an anoxic basin, oxic basin, and iron precipitation apparatus. Methods: This study was conducted in order to improve the effect of nitrogen and phosphorus removal in domestic wastewater using the FNR (Ferrous Nutrient Removal) process which features an iron precipitation reactor in anoxic and oxic basins. The average concentration of TN and TP was analyzed in a pilot plant ($50m^3/day$). Results: The removal rate of T-N and T-P were 66.5% and 92.8%, respectively. The $NH_3-N$ concentration of effluent was 2.62 mg/l with nitrification in the oxic basin even though the influent was 17.7 mg/l. The $NO_3$-N concentration of effluent was 5.83 mg/l through nitrification in oxic basin even though the influent and anoxic basin were 0.82 mg/l and 1.00 mg/l, respectively. The specific nitrification of the oxic basin ($mg.NH_3$-Nremoved/gMLVSSd) was 16.5 and specific de-nitrification ($mg.NO_3$-Nremoved/gMLVSSd) was 90.8. The T-P removal rate was higher in the oxic basin as T-P of influent was consumed at a rate of 56.3% in the anoxic basin but at 90.3% in the oxic basin. The TP removal rate (mg.TP/g.MLSS.d) ranged from 2.01 to 4.67 (3.06) as the volume loading of T-P was increased, Conclusions: The test results showed that the electrolysis of iron is an effective method of phosphorus removal. Regardless of the temperature and organic matter content of the influent, the quality of phosphorus in the treated water was both relatively stable and high due to the high removal efficiency. Nitrogen removal efficiency was 66.5% because organic matter from the influent serves as a carbon source in the anoxic basin.

• 한국환경과학회지
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• 제18권7호
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• pp.819-824
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• 2009

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.

• 한국환경과학회지
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• 제16권1호
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• pp.45-53
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• 2007

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.

• Asian-Australasian Journal of Animal Sciences
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• 제13권5호
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• pp.698-701
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• 2000

To prevent surface and underground water pollution, wastewater treatment is essential. Four bench-scale activated sludge units (10 L operational volumes) were operated at 5, 10 and $20^{\circ}C$ for evaluation of treatment efficiencies with typical wastewater from swine housing. The units were set for a 24-hour cycle. As compared to the conventional process, high removal efficiencies for organic substances, nitrogen and phosphorus in swine wastewater were obtained simultaneously with an intermittent aeration process (lAP). The NOx-N produced during an aeration period was immediately reduced to nitrogen gas (e.g. $N_2$ or $N_2O$) in the subsequent non-aeration periods, and nitrification in aeration periods occurred smoothly. Under these conditions, phosphorus removal occurred with the release of phosphorus during the non-aeration periods followed by the excess uptake of phosphorus in the activated sludge during aeration periods. It was confirmed that the lAP had a better ability to remove pollutants under both low temperatures and high nitrogen loading conditions than the ordinary method did. In addition to that, the total emission of $N_2O$ from lAP was reduced to approximately 1/50 of the conventional process for the same loading. By adopting an adequate aeration programme for individual swine wastewater treatment, this system will provide a promising means for nitrogen and phosphorus control without pH control or addition of methanol.

• 한국토양비료학회지
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• 제44권4호
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• pp.539-544
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• 2011

The relative focus about phosphorus (P) which causes eutrophication characterized by increased growth of undesirable algae has increased in recent years. Phosphorus forms in soil and water include both organic and inorganic forms. There are also a large number of soil P determination methods that have been designed to account for various types of P and mechanisms controlling the chemistry of P in soil, water, and residual materials for environmentally relevant forms of P. However, phosphorus forms in soil, water, and residual materials are also difficult to standardize with any reasonable consensus, due to the number of different disciplines involved. Hence, it is essential to accurately define how P can be measured in soil, water, or residual material samples to avoid potential misinterpretations or inappropriate recommendations in determining amount and types of P. Therefore, we reviewed the testing methods which have appeared in the scientific literature to provide an overview of the soil test P most commonly used.

• 한국환경과학회지
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• 제14권9호
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• pp.861-871
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• 2005

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 I : I. 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-I was 2 : 3, and those in SBBR-2 and SBBR-3 were I : 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.

• Journal of Plant Biology
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• 제11권3호
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• pp.1-7
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• 1968

Organic matter in rice-paddy soils exercises two antagonistic effects on the rice plant under water-logged conditions in growing season in the course of its decomposition: It liberates mineral nutrients and promotes soil fertility. On the other hand, however, it demands oxygen for its decay and therefore competes with rice roots for this element, when applied in large quantity of fresh status. For the practical end of rice culture, it is most desirable that these two effects should not contend with each other. To determine the proper content of organic materials to be applied, the influences of varied amounts of a homogeneous mixture of dried green manure, ranging from 0 to 20g/pot (1/20,000 tanbo), upon hte growth of rice was investigated in a sand culture. Labeled phosphorus fertilizer was also used in the form of KH232PO4 to evaluate the availability of this nutrient in the soil. Under the present experimental conditions, green mature seems to have influenced little on the growth of rice, except on number of grains produced and grains/straw ratio. Moreover, no sympton of growth inhibition is obsrvable even by the largest amount of its application. The available phosphorus, as estimated by A-value, appears to have increased, as the amount of organic materials applied increases. In view of the fact that pure sand instead of a paddy soil is used in this culture, the present results would not be directly applicable to practical rice farming. Besides, the estimated A-value is in need of further study, since it varies according to method of application, as suggested by Nishigki et. al. (1958).

• 해양환경안전학회지
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• 제27권5호
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• pp.630-638
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• 2021

본 연구에서는 와편모조류 Alexandrium affine(LIMS-PS-2345)의 생장에 미치는 용존태 무기 및 유기 영양염의 영향을 조사하였다. 영양염 흡수 동력학 실험에서 A. affine의 최대흡수속도(ρ_max)와 반포화상수(Ks)는 질산염에서 77.0 pmol/cell/hr과 17.6 μM, 인산염에서 15.5 pmol/cell/hr과 3.88 μM로 산출되어, 무기영양염에 대하여 높은 요구량 및 낮은 친화성을 가지고 있는 것으로 나타났다. 유기 영양염에 따른 A. affine의 생장속도를 확인한 결과, 유기 질소 urea, glycine와 유기 인 adenosine triphosphate(ATP), glycerol phosphate(Glycerol-P) 첨가구에서 무기 영양염 첨가구의 70 % 이상 생장속도를 보였다. 따라서 낮은 무기 영양염 환경에서 A. affine의 우점화와 종간경쟁에서 우위를 위해서는 용존태 유기 영양염의 이용이 필요할 것으로 생각된다.