• Title/Summary/Keyword: phosphorus acid

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Trends of phosphorus recovery technology from sewage sludge ash by wet chemical method (습식 화학적 방법에 의한 하수 슬러지 소각재에서의 인 회수 기술동향)

  • Lee, Min-Su;Kim, Dong-Jin
    • Journal of Korean Society of Water and Wastewater
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    • v.32 no.2
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    • pp.131-143
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    • 2018
  • Phosphorus (P) is a limited, essential, and irreplaceable nutrient for the biological activity of all the living organisms. Sewage sludge ash (SSA) is one of the most important secondary P resources due to its high P content. The SSA has been intensively investigated to recover P by wet chemicals (acid or alkali). Even though $H_2SO_4$ was mainly used to extract P because of its low cost and accessibility, the formation of $CaSO_4$ (gypsum) hinders its use. Heavy metals in the SSA also cause a significant problem in P recovery since fertilizer needs to meet government standards for human health. Therefore, P recovery process with selective heavy metal removal needs to be developed. In this paper some of the most advanced P recovery processes have been introduced and discussed their technical characteristics. The results showed that further research is needed to identify the chemical mechanisms of P transformation in the recovery process and to increase P recovery efficiency and the yields.

Effects of Chemical Amendments on Phosphorus and Total Volatile Fatty Acids in Hanwoo Slurry (한우액상분뇨에 화학제재를 첨가 시 인과 총 휘발성지방산 함량에 미치는 영향)

  • Choi, In-Hag;Choi, Jung-Hoon
    • Journal of Environmental Science International
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    • v.18 no.7
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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.

Nano Crystalline Change by Heat Treatment

  • Sun, Yong-Bin
    • Journal of the Semiconductor & Display Technology
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    • v.12 no.4
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    • pp.55-59
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    • 2013
  • Mold die sticking arises from silica filler abrasion to the cavity surface. Ni-P electroplating was examined to substitute conventional hard Cr plating. More than 4% of Phosphorus in the electroplated film produces nano crystal structure and annealing makes $Ni_3P$ precipitated to get hardness values equivalent to hard Cr.

BIOCHEMICAL MODEL AND MECHANISM FOR ACINETOBACTER NITRITE INHIBITION

  • Lee, Chan-Won;Weon, Seung-Yeon
    • Environmental Engineering Research
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    • v.10 no.1
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    • pp.22-30
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    • 2005
  • Nitrite accumulation is not unusual in batch processes such as sequencing batch reactor (SBR) with high-strength of ammonium or nitrate wastewaters. A possible mechanism of nitrite inhibition on Acinetobacter was depicted in a biochemical model, which the protonated species, nitrous acid form of nitrite, affects proton relating transport at the proton-pumping site crossing the cell membrane under unlimited carbon and phosphorus conditions. This effect exerts inhibition of phosphorylation under aerobic condition and yields low APT/ADP ratio, consequently decrease poly-P synthesis and phosphorus uptake from outside the cell in the model.

노출평가를 위한 TLV 근거 - PHOSPHORUS PENTASULFIDE (오황화인)

  • Kim, Chi-Nyeon
    • 월간산업보건
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    • s.384
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    • pp.19-23
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    • 2020
  • 눈, 피부 및 호흡기 자극의 가능성을 최소화하기 위해 오황화인(Phosphorus pentasulfide)에 대한 직업적 노출기준 TLV-TWA는 1 mg/㎥ 그리고 TLV-STEL은 3 mg/㎥으로 권고하였다. 오황화인에 대한 독성 자료는 거의 없으며 오황화인은 습한 공기에서 인산(Phosphoric acid)과 황화수소(Hydrogen sulfide)로 쉽게 가수 분해된다는 사실에 근거하여 인산에 대한 독성 자료로 TLV를 권고하였다.(현재의 인산에 대한 TLV 문서 참조) 피부 흡수(Skin), 감작제(SEN), 그리고 발암성 표기에 대한 경고주석(notation)을 권고하기에는 유용한 자료가 충분하지 않다.

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Synthesis of Alkylenediaminoalkyl-bis-Phosphonic Acid Derivatives (알킬렌디아미노알킬-비스-포스폰산 유도체의 합성)

  • Chung, Yeong-Jin;Jin, Eui
    • Journal of the Korean Applied Science and Technology
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    • v.30 no.1
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    • pp.1-8
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    • 2013
  • Four kinds of new alkylenediaminoalkyl-bis-phosphonic acid derivatives with alkylenediaminoalkyl functional groups in the molecule were synthesized and their smoke density(Ds) were tested. These alkylenediaminoalkyl-bis-phosphonic acid derivatives were prepared in yields(76-97.3%) by one step reaction of the phosphorus acid with amine and aldehyde. Smoke density was measured by the method of ASTM E 662. The values of smoke density were obtained from 234.7 to 437.9. The smoke density of compounds with two phosphonic acid structures were increased more than that of compounds with one phosphonic acid structure. In addition, there was correlation between the smoke density and the number of nitrogen atoms in amino group attached to mono- or di-phosphonic acids group.

Preparation and Characterization of PU Flame-Retardant Coatings Using Modified Polyesters Containing Phosphorus and Chlorine (인과 염소 함유 변성폴리에스터에 의한 PU 난연도료의 제조 및 도막특성)

  • Park, Hong-Soo;Shim, Il-Woo;Jo, Hye-Jin;Hahm, Hyun-Sik;Sung, Ki-Chun
    • Journal of the Korean Applied Science and Technology
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    • v.23 no.1
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    • pp.77-84
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    • 2006
  • Modified polyesters (TTBA-10C, -20C, -30C) that contain phosphorus and chlorine were synthesized by the condensation polymerization of tetramethylene bis(orthophosphate), neohexanediol trichlorobenzoate, 1,4-butanediol and adipic acid, in which tetramethylene bis(orthophosphate) and neohexanediol trichlorobenzoate were prepared previously in our laboratory. In this study, two-component flame-retardant polyurethane coatings (TTBA-10C/HDI-trimer=TTHD-10C, TTBA-20C/ HDI-trimer= TTHD-20C, TTBA-30C/HDI-trimer= TTHD-30C) were obtained by curing at room temperature with the synthesized TTBAs and hexamethylene diisocyanate (HDI)-trimer as a curing agent. The obtained TTHDs were made into coating samples and used as test samples for various physical properties. The physical properties of the flame-retardant coatings containing chlorine and phosphorus groups were generally inferior to those containing only phosphorus group. Flame retardancy was tested by vertical and horizontal combustion method, and $45_{\circ}$ Meckel burner method. Since the retardancy of flame-retardant coatings containing chlorine and phosphorus groups was better than that containing only phosphorus group, it could be concluded that the retardancy by the synergism effect of chlorine and phosphorus groups exhibited.

Studies on the Physiological Chemistry of Seed Development in Ginseng Seed (인삼식물의 종자발육 과정에 있어서의 생리화학적 연구)

  • Hee-Chun Yang
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.17
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    • pp.115-133
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    • 1974
  • This study was done on the metabolism of chemical components during the seed development of ginseng. The changes of the chemical components were inspected in the following periods: from the early stage of flower organ formation to flowering time, from the early stage of fruiting to maturity, during the moisture stratification before sowing. From flower bud forming stage to meiosis stage, the changes in the fresh weight, dry weight, contents of carbohydrates, and contents of nitrogen compounds were slight while the content of TCA soluble phosphorus and especially the content of organic phosphorus increased markedly. From meiosis stage to microspore stage the fresh and dry weights increase greatly. Also, the total nitrogen content increases in this period. Insolub]e nitrogen was 62-70% of the total nitrogen content; the increase of insoluble nitrogen seems to have resulted form the synthesis of protein. The content of soluble sugar (reducing and non-reducing sugar) increases greatly but there was no observable increase in starch content. In this same period, TCA soluble phosphorus reached the maximum level of 85.4% of the total phosphorus. TCA insoluble phosphorus remained at the minimum content level of 14.6%. After the pollen maturation stage and during the flowering period the dry weight increased markedly and insolub]e nitrogen also increased to the level of 67% of the total nitrogen content. Also in this stage, the organic phosphorus content decreased and was found in lesser amounts than inorganic phosphorus. A rapid increase in the starch content was also observed at this stage. In the first three weeks after fruiting the ginseng fruit grows rapidly. Ninety percent of the fresh weight of ripened ginseng seed is obtained in this period. Also, total nitrogen content increased by seven times. As the fruits ripened, insoluble nitrogen increased from 65% of the total nitrogen to 80% while soluble nitrogen decreased from 35% to 20%. By the beginning of the red-ripening period, the total phosphoric acid content increased by eight times and was at its peak. In this same period, TCA soluble phosphorus was 90% of total phosphorus content and organic phosphorus had increased by 29 times. Lipid-phosphorus, nucleic acid-phosphorus and protein-phosphorus also increased during this stage. The rate of increase in carbohydrates was similar to the rate of increase in fresh weight and it was observed at its highest point three weeks after fruiting. Soluble sugar content was also highest at this time; it begins to decrease after the first three weeks. At the red-ripening stage, soluble sugar content increased again slightly, but never reached its previous level. The level of crude starch increased gradually reaching its height, 2.36% of total dry weight, a week before red-ripening, but compared with the content level of other soluble sugars crude starch content was always low. When the seeds ripened completely, more than 80% of the soluble sugar was non-reducing sugar, indicating that sucrose is the main reserve material of carbohydrates in ginseng seeds. Since endosperm of the ripened ginseng seeds contain more than 60% lipids, lipids can be said to be the most abundant reserve material in ginseng seeds; they are more abundant than carbohydrates, protein, or any other component. During the moisture stratification, ginseng seeds absorb quantities of water. Lipids, protein and starch stored in the seeds become soluble by hydrolysis and the contents of sugar, inorganic phosphorus, phospho-lipid, nucleic acid-phosphorus, protein phosphorus, and soluble nitrogen increase. By sowing time, the middle of November, embryo of the seeds grows to 4.2-4.7mm and the water content of the seeds amounts to 50-60% of the total seed weight. Also, by this time, much budding material has been accumulated. On the other hand, dry stored ginseng seeds undergo some changes. The water content of the seeds decreases to 5% and there is an observable change in the carbohydraes but the content of lipid and nitrogen compounds did not change as much as carbohydrates.

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Synthesis of Modified Polyester Containing Phosphorus and Chlorine for Flame-Retardant Coatings (난연도료용 인과 염소 함유 변성폴리에스테르의 합성)

  • Park, Hong-Soo;Shim, Il-Woo;Jo, Hye-Jin;You, Hyuk-Jae;Kim, Yeoung-Chan
    • Journal of the Korean Applied Science and Technology
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    • v.22 no.3
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    • pp.257-269
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    • 2005
  • This study was focused on the maximization of flame-retardancy of polyesters by a synergism of simultaneously introduced chlorine and phosphorus into polymer chains of modified polyesters. To prepare modified polyesters, reaction intermediates, TD-adduct (prepared from trimethylolpropane /2,4-dichlorobenzoic acid (2,4-DCBA)) and TMBO (prepared from tetramethlene bis (orthophosphate)), were prepared first, then condensation polymerization of the prepared intermediates, adipic acid, and 1,4-butanediol were carried out. In the condensation polymerization, the content of phosphorus was fixed to be 2wt%, and the content of 2,4-DCBA that provides chlorine component was varied to be 10, 20, and 30wt%, and we designated the prepared modified polyesters containing chlorine and phosphorus as ABTTs. The prepared intermediates and modified polyesters were characterized with FT-IR, NMR, GPC, and TGA analysis. Average molecular weight and polydipersity index of the preparation of ABTTs were decreased with increasing 2,4-DCBA content because of the incease in hydroxyl group that retards reaction. We found that the thermal stability of the prepared ABTTs increased with chlorine content at high temperatures.