• Biotechnology and Bioprocess Engineering:BBE
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• 제5권6호
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• pp.431-435
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• 2000

The goal of this research is to compare the metal binding characteristics of an anoxic selector activated sludge system and a conventional activated sludge system. Metal biosorption by biomass harvested from experimental systems was determined by a series of batch experiments. Heavy metals studied in this research were zinc, cadmium, and nickel. The sorption isotherm showed that the selector sludge had significantly higher sorption capacity than did the control sludge. Metal biosorption behavior closely followed a Freundlich isotherm model for equilibrium concentrations. ECP contents of biomass estimated by alkali extraction technique showed that ECP levels in the selector sludge significantly higher than that in the sludge harvested from the conventional system, indicating that the higher metal sorption capacity of selector sludge may be due to the selection of the ECP-producing bacteria (i.e., Zoogloea sp.) by the selector system.

• 한국식품과학회지
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• 제11권1호
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• pp.1-7
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• 1979

맥주(麥酒) 공장폐수(工場廢水) 활성오니(活性汚泥)의 사료적(館料的) 가치(價値)를 구명(究明)하기 위하여 병아리 사료(飼料)에 활성오니(活性汚泥)를 3% 간격으로 12%까지 첨가(添加)하여 본시험(本試驗)을 실시(實施)하였던 바 다음과 같은 결과(結果)를 얻었다. 1 성분분석(成分分析) 시험(試驗) (1) 활성오니(活性汚泥)의 조단백질(粗蛋白質) 함량(含量)은 42,50%였고 조회분(粗灰分)은 15.69%였으며 ME 함량(含量)은 kg당(當) 2060 kcal였다. (2) 활성오니(活性汚泥)의 총(總)아미노산 함량(含量)은 42.24%로서 조단백질함량(粗蛋白質含量)의 99%가 순(純)아미노산(酸) 이었고 특(特)히 methionine과 threonine이 많이 들어 있었다. (3) 활성오니(活性汚泥)의 무기물함량(無機物含量)은 P,Mg, Cu, Fe등(等)은 충분(充分)하나 Ca는 상당히 부족했다. 2. 포양(飽養) 시험(試驗) (1) 병아리의 성장(成長)은 활성오니(活性汚泥)의 첨가수준(添加水準)이 증가할 수록 감소되는 경향이었으나 각처리간(各處理間)에 통계적(統計的)인 유의성(有意性)은 없었다. (2) 사료섭취량(飼料攝取量)은 활성오니(活性汚泥)의 첨가수준(添加水準)이 증가할 수록 매우(p<0.05) 증가했다. (3) 사료요구율(飼料要求率)은 활성오니(活性汚泥)의 첨가수준(添加水準)이 증가할 수록 증가했으나 각처리간(各處理間)에 통계적(統計的)인 유의성(有意性)은 없었다. 3. 대사시험(代謝試驗) (1) 고형물(圖形物) 이용률(利用率)은 활성오니(活性汚泥)의 첨가수준(添加水準)이 증가할수록 감소되는 경향이었으나 각처리간(各處理間)에 통계적(統計的)인 유의성(有意性)은 없었다. (2) 조단백질(粗蛋白質) 이용률(利用率)은 활성오니(活性汚泥)의 첨가수준(添加水準)이 증가 할 수록 매우 (p<0.01) 감소되어 대조구 및 3%구(區)가 6, 9. 12%구(區)에 비하여 조단백질이용률(粗蛋白質利用率)이 높았다. (3) 조회분(粗灰分) 이용률(利用率)은 활성오니(活性汚泥)의 첨가수준(添加水準)이 증가할수록 매우 (p<0.05) 감소되었다. (4) NFE 이용률(利用率)은 활성오니(活性汚泥)의 첨가수준(添加水準)이 증가할수록 약간 감소되는 경향이었으나 각(各) 처리구간(處理區間)에 통계적(統計約)인 유의성(有意性)은 없었다. 따라서 본시험(本試驗)에 의하면 맥주공장폐수(麥酒工場廢水) 활성오니(活性汚泥)를 병아리 사료(飼料)에 $6{\sim}9%$정도 첨가(添加)할 수 있을 것 같다.

• 상하수도학회지
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• 제11권3호
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• pp.67-78
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• 1997

The objective of study was to examine to transient response of hydraulic shock loading in activated sludge process for treatment of municipal sewage. The general experiment approach was to operate the system under steady-state(pre-shock), then to apply step changes during 24hours in fourfold hydraulic shock loading at the same organic loading. Performance was assessed in both the transient state and the new steady-state(post-shock). Three bench scale activated sludge reactors were operated to investigate the effect of fourfold hydraulic shock loading on TSS and COD removal efficiency. In activated sludge reactors operated with 13hours and 7hours of HRT, effluent quality of all reactors was not changed for few effects, and also showed no foaming and no sludge bulking. Those results are the same as sludge withdrawn reactors. The effect of fourfold hydraulic shock loading on the activated sludge reactors operated with 3hours of HRT was most severe. The effluent quality was deteriorated significantly and generate foaming in reactors. Less than 24hours after the fourfold shock loading applied, the activated sludge system seemed to attain a new steady-state condition as show by effluent.

• 상하수도학회지
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• 제35권2호
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• pp.153-162
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• 2021

The effects of activated carbon originated Ballasted Flocculant (BF) on the settleability of activated sludge and the recovery of BF by Hydro-cyclone (HC) were analyzed experimentally. Two kinds of BF (M-I: 125-250 ㎛, M-II: 250-425 ㎛ in dia.) and three kinds of activated sludges with different SS concentration (2,300-7,100 mg/L) were applied for this study. With the dosage variation of BF from 0.14 to 1.3 g-BF/g-SS, we could obtain 24-31% improvement in SV30 (Sludge Volume after 30min sedimentation) for the lowest SS concentration sludge (2,300 mg/L). Whereas the SV30 improvement was much higher as 44-48% for the highest SS concentration sludge (7,100 mg/L). The settling characteristics of the sludge with BF followed Vesilind model the best among three models (Vesilind, Takacs and Cho model). HC could effectively separate BF with the separation efficiency of 70-90% and over 95% separation efficiency could be obtained when the HC was applied twice.

• Environmental Engineering Research
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• 제20권1호
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• pp.105-109
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• 2015

Triclosan is a synthetic antimicrobial agent used in numerous industrial and personal care products. Triclosan collected in wastewater treatment plants can be biodegraded up to 80%. However, little is studied about the abundances of known triclosan-degrading bacteria in activated sludge systems. A previous study reported that Sphingopyxis strain KCY1 isolated from activate sludge can cometabolically degrade triclosan. Recently, a quantitative PCR (qPCR) assay specific to strain KCY1 has been developed. Thus, this study investigated the abundance of strain KCY1 in three different activated sludge wastewater treatments using a qPCR assay. Additionally, ammonia-oxidizing bacteria (AOB), known as triclosan-degraders, and amoA gene were quantified. Strain KCY1 were detected in activated sludge samples from three different wastewater treatment plants. The concentrations of strain KCY1 and AOB were on the order of $10^5-10^6$ gene copies/mL, while amoA gene concentration was on the order of $10^4$ gene copies/mL.

• 한국환경과학회지
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• 제17권12호
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• pp.1343-1351
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• 2008

The activated sludge obtained from wastewater coke oven plant was immobilized by entrapment with polyethylene glycol (PEG). The effects of several factors on the biodegradation of $CN^-$ from. synthetic wastewater were investigated using batch and continuous reactors. The degradation rate of $CN^-$ increased with increasing of the immobilized bead volume in the reactor. Approximately 7.65mg/L of $NH_4-N$ was produced upon the degradation of 35mg/L of $CN^-$. When high concentrations of the toxic cyanide complex were used in the testing of cyanide degradation, the free activated sludge could be inhibited more than that of the immobilized activated sludge. When the phenol concentration was higher than 400mg/L in the synthetic wastewater, approximately 98.4% of $CN^-$ was removed within 42 hours by the immobilized activated sludge. However, the cyanide was not completely degraded by the tree activated sludge. This indicates that high phenol concentrations can act as a toxic factor for the free activated sludge. A $CN^-$ concentration of less than 1mg/L was achieved by the immobilized sludge at the loading rate of 0.025kg $CN^-/m^3-d$. Moreover, it was found that the HRT should be kept for 48 hours in order to obtain stable treatment conditions.

• 상하수도학회지
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• 제22권5호
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• pp.551-559
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• 2008

An experimental study was carried out to evaluate the potential of flotation process for the secondary clarifier of an activated sludge process. Flotation techniques, applied in this study, include electrofloation (EF) which generated fine bubbles smaller than $35{\mu}m$ in average and diffuser flotation (DF) which generated fine bubbles smaller than $55{\mu}m$ in average. The batch experiments were done with activated sludge displaying various characteristics. It was shown that the efficiency of solids/liquid separation was reduced as the diluted sludge volume index ($DSVI_{30}$) of activated sludge increased. The dependency, however, gradually decreased as the gas to solids (G/S) ratio increased. Thickening efficiency of EF was more than 2~10 times and DF process was more than 1.5~5 times as compared with gravity sedimentation (GS). Stable sludge blanket was maintained regardless of sludge settleability when the G/S ratio was 0.019 in the EF. On the other hand, Serious deterioration in the sludge blanket was observed in the DF depends on G/S ratio and sludge settleability. And For EF and DF, the suspended solids concentration of effluent was not nearly influenced on settleability of activated sludge and more clear than GS. A biological nutrient removal (BNR) process, combined with EF as a secondary clarifier was operated for three months. The mean MLSS (mixed liquid suspended solids) concentration in the reactor and mean solids concentration of return sludge were estimated to be 5,340 mg/L and 16,770 mg/L, respectively. The water quality of effluent was considerably stable and low value was accomplished, that was, standard suspended solids concentration $0.07{\pm}0.51mg/L$ and standard turbidity $1.44{\pm}0.56NTU$. The EF could be applicable for enhancement of efficiency of activated sludge system as well as improvement of the water quality of effluent.

• KSBB Journal
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• 제25권1호
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• pp.67-72
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• 2010

In this study, we developed a comprehensive correlation for better prediction of the activated sludge concentration in the relationship between measurement of optical density by the Beer's law and sludge properties. Effects of activated sludge properties, which are sludge types and anaerobic storage time, show that absorbance deviation for sludge properties decreased on wavelength of light source near to 950 nm. We also developed a method to measure limitation with non-linear correlation on the measurement of high concentration by the Beer's law using a double layer probe cell and empirical equations.

• 상하수도학회지
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• 제19권3호
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• pp.295-300
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• 2005

The performances of electroflotation (EF) on the thickening of activated sludge were investigated using laboratory scale batch flotation reactors. Four activated sludges including bulking sludges were tested. After 30minutes of EF operation, 57-84 % of sludge volume reduction could be achieved by EF, while only about 1.5-14% could be obtained by gravity thickening for the same period. After thickening the effluent water quality in terms of TCOD, SS, and turbidity was improved by EF operation for all sludge samples. It is induced that the air bubbles entrapped in the thickened sludge play a key role in the observed improvement of sludge thickening and effluent quality.

• 공업화학
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• 제27권1호
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• pp.62-67
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• 2016

본 연구에서는 정수슬러지를 원료로 사용하여 펠렛형 흡착제를 제조하고 질소흡착법, XRD, XRF 및 암모니아 승온탈착법 등을 사용하여 물리 화학적 특성을 분석하였다. 정수슬러지 유래 펠렛형 흡착제와 첨착활성탄의 암모니아 및 포름알데히드 기체의 흡착 성능을 비교하였다. 정수슬러지로부터 제조된 펠렛형 흡착제는 첨착활성탄보다 표면적과 기공부피는 훨씬 작지만 암모니아를 훨씬 더 많이 흡착할 수 있었다. 이는 정수슬러지로부터 제조된 펠렛형 흡착제 표면에 산점이 훨씬 더 많이 분포해 있어서 화학흡착에 의해 암모니아를 흡착하기 때문이다. 반면에, 산성가스인 포름알데히드 가스 흡착의 경우는 넓은 표면적과 발달된 기공으로 인하여 첨착활성탄의 흡착성능이 정수슬러지로부터 제조된 펠렛형 흡착제에 비해 훨씬 우수하였다.