본 연구는 잉여슬러지와 차아염소산나트륨을 혼합하여 제조한 차아염소산나트륨 처리 슬러지를 침지형 분리막이 설치된 생물반응조에 주입하여 수처리 미생물에 기질을 공급하고 수처리에 적합한 pH와 알칼리도를 유지함으로써 응집제 주입 없이 방류수의 총질소 농도 20 mg/L, 총인 농도 0.2 mg/L 이하로 처리할 수 있는 MBR 하수처리공정을 개발하였다. 개발된 공정은 별도의 응집제 주입 없이 질소와 인의 법적 방류수 수질기준 을 만족하였고, 향후 하수처리장 약품비용 절감에도 기여할 것으로 기대된다.

The objective of this study was to evaluate the possibility of simultaneous removal of ammonium, nitrate and phosphorus in water using the zeocarbon. In this study, the surface of zeocarbon was modified by acid because of difficulty in application of water treatment. After surface modification, the strength was enhanced about 62% higher than that of original one. The removal efficiency of ammonium and nitrate using the modified zeocarbon was about 47% and 32%, respectively and were higher than that of zeocarbon. In batch type experiment on the simultaneous removal of ammonium, nitrate and phosphorus, the presence of phosphorus did not have influence on nitrogen removal efficiency. Concomitantly, removal efficiency of phosphorus was obtained was about 35%. This indicates that the surface modified zeocarbon can be applied for simultaneous removal of nitrogen and phosphorus. Consequently, our results could be used as basic data to design of one-stage nitrogen/phosphorus simultaneous removal system.

창포를 이용하여 질소와 인의 농도별, 식물의 생장단계별, 오염수의 체류시간별로 질소와 인의 제거효과를 분석하였던 바, 그 결과를 요약하면 다음과 같다. 체류 1시간 후에 수중의 질소와 인의 함량을 현저히 감소시켰으나, 2~4시간 후에는 감소율이 극히 낮았다. 이러한 현상은 식물의 생장초기, 생장기, 생장최성기에서 동일하였다. 수중에 질소와 인의 함량이 많을수록 제거율이 높았고, 인보다는 질소의 제거효과가 크게 나타났다. 생장최성기에 가장 많은 질소와 인을 제거하였고 다음으로 생장기, 생장초기의 순이었으나, 생장단계간의 차이는 극히 작았다. 동일 포트에 4일 동안 체류시킨 것보다 2일 체류 후에 다른 포트로 시험수를 옮긴 것이 질소와 인의 제거율이 약간 높았다.

경기도 양평군 수입천에서 대형 군락을 형성하여 자생하는 갯버들의 영양염류의 농도와 수리학적체류시간에 따른 질소.인 흡수 실험 결과로서 NH4-N, NO3-N, PO4-P제거효율은 저농도에서 체류 시간이 길 때 높은 경향을 보였고, 제거능은 고농도와 짧은 체류시간에서 높은 경향으로 나타났다. 유입농도와 체류시간에 따른 지상부 1g당 제거능 추정식을 구하였다. 수입천 갯버들의 현존량은 4,880.81g/m2로 추정되었고, 현존량과 제거

The pilot plant experiment was performed to investigate phosphorus and nitrogen removal from domestic wastewater by MLE process combined with aluminum corrosion reactor. When operating 0.5Q and 1Q to internal recycle and sludge recycle in the MLE process, the effluent CODMn concentration of internal recycle 0.5Q were higher than internal recycle 1Q, the removal efficiency rates of NH3-N in the internal recycle 0.5Q were was higher than internal recycle 1Q. Denitrification rates were about 86.8% in internal recycle and sludge recycle 0.5Q. When operating 0.5Q to internal recycle and sludge recycle in the MLE process, the removal efficiency rates of total nitrogen was the highest. The removal efficiency rates of total phosphorus was about 91.5% in the aluminum corrosion reactor.

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.

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.

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.

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.

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.

Sequencing Batch Reactor(SBR) experiments for organics and nutrients removal have been conducted to find an optimum anaerobic/anoxic/aerobic cycling time and evaluate the applicability of oxidation-reduction potential(ORP) as a process control parameter. In this study, a 6 ℓ bench-scale plant was used and fed with night-soil wastewater in K city which contained TCODcr : 10,680 ㎎/ℓ, TKN : 6,893 ㎎/ℓ, NH_4^+ -N : 1,609 ㎎/ℓ, PO_4^3- -P : 602 ㎎/ℓ on average. The cycling time in SBRs was adjusted at 12 hours and 24 hours, and then certainly included anaerobic, aerobic and anoxic conditions. Also, for each cycling time, we performed 3 series of experiment simultaneously which was set up 10 days, 20 days and 30 days as SRT. From the experimental results, the optimum cycling time for biological nutrient removal with night-soil wastewater was respctively 3hrs, 5hrs, 3hrs(anaerobic-aerobic-anoxic). Nitrogen removal efficiency was 77.9%, 77.9%, 81.7% for each SRT, respectively. When external carbon source was fed in the anoxic phase, ORP-bending point indicating nitrate break point appeared clearly and nitrogen removal efficiency increased as 96.5%, 97.1%, 98.9%. Phosphate removal efficiency was 59.8%, 64.5%, 68.6% for each SRT. Also, we finded the applicability of ORP as a process control parameter in SBRs.