미생물 촉매제를 이용한 슬러지 감량화에 관한 연구

신동철,양은지,이연구,박철휘 대한환경공학회 2018 대한환경공학회지 Vol.40 No.2

In this study, evaluation of sludge reduction and advanced treatment were performed using the batch test. Sludge reduction rate was checked by batch experiment on excess sludge and aerobic sludge. The maximum sludge reduction rate was 37% for excess sludge and 34% for aerobic sludge. As a result of the batch process, the SCODCr 26%, S-N 62% and S-P 82% were removed. Therefore, it is possible to reduce the amount of sludge during the microbial catalyst injection and to remove the organic matter and nutrients simultaneously. In particular, the removal efficiency of S-P is higher than that of the conventional treatment. Especially, the removal efficiency of S-P was higher than that of conventional A2O treatment. In order to evaluate sludge reduction ability after microbial catalytic agent injection, the yield of heterotrophic biomass (YH), decay coefficient of heterotrophic biomass (bH) and observed or net biomass yield (Yobs) were estimated. The yield of YH was 0.32 and 0.25, which was less than 50% of the YH (BOD based) value of general heterotrophic microorganisms. On the other hand, bH was 0.232 day-1, which is a general value. Therefore, it is considered that the main factor of sludge reduction using microbial agent is due to the decrease of biomass build-up rather than the death of sludge microorganisms. 본 연구는 batch-test를 통해 미생물 촉매제의 적정 주입량을 산정하고 슬러지 감량화에 대하여 검토하였다. 잉여슬러지와 호기조 슬러지를 대상으로 batch 실험을 통해 슬러지 감량화율을 확인하였으며 잉여슬러지는 최대 37%, 호기조 슬러지최대 34%의 슬러지 감량화율을 나타내었다. Batch test를 통하여 고도처리 효율을 산정한 결과 SCODCr 26%, S-N 62%, S-P 82% 제거되었다. 따라서 미생물 촉매제 주입 시 슬러지 감량화가 가능하고 유기물 및 영양염류의 동시제거가 가능한 것으로나타났으며 특히 S-P의 경우 기존 처리공정의 인 제거효율보다 높은 제거효율을 보였다. 미생물 촉매제 주입 이후 슬러지감량능을 평가하기 위하여 종속영양미생물 생산계수(YH), 종속영양미생물 사멸계수(bH), 미생물 생산계수(Yobs)의 산정을 통해 분석하였다. YH 산정결과 0.32, 0.25으로 나타났으며 일반적인 종속영양미생물의 YH (BOD based) 값의 50% 이하의 값을보였다. 반면에 bH는 0.232 day-1로 일반적인 수치를 보여 미생물 촉매제를 이용한 슬러지 감량의 주 요인은 슬러지 미생물의사멸이 아닌 증식 저하에 따른 것이라 판단된다.

알칼리 및 오존 병합 전처리를 이용한 슬러지 감량화 공정의 실증플랜트 연구

김홍석 ( Hong-suck Kim ),김병군 ( Byung-goon Kim ),서인석 ( In-seok Seo ),김연권 ( Yeon-kwon Kim ) 한국환경기술학회 2011 한국환경기술학회지 Vol.12 No.4

슬러지 감량화 공정(인 용출조-알칼리 및 오존 병합 전처리-발효농축조-결정화 침전조)과 수처리 공정(KSMBR)을 연계한 실증플랜트 연구를 통해 다음과 같은 결과를 얻었다. 실증플랜트 운전 3개월 기간동안 슬러지 감량화 공정은 안정적으로 운영되었으며, 감량화 및 가용화율은 각각 평균 35% 및 20.4%였다. 슬러지 감량화 공정의 결정화 침전조에서는 가용화된 슬러지에서 용출된 다량의 인을 Ca²⁺ 주입을 통해 인회석(hydroxyapatite) 형태의 결정물질로 약 80.2%의 인을 제거하였으며, 인이 제거된 가용화된 슬러지를 외부탄소원으로 수처리 공정인 KSMBR공정의 혐기성 반응조에 주입하여 수처리 공정의 인 제거효율을 40%까지 향상시킬 수 있었다. 따라서 제안한 감량화 공정은 슬러지 감량화 뿐 아니라 유용자원인 인의 회수와 고도처리 공정의 효율향상이 가능한 외부탄소원으로 활용이 가능한 감량화 공정으로 활용가치가 높을 것으로 판단된다. Full scale of sludge reduction process(P release reactor-combined use of alkali and ozone pretreatment-fermentation-crystallization) with KSMBR process was operated for 3 months to evaluate the reduction efficiency and solubility of sludge and the effluent water quality of KSMBR process. The average efficiencies of sludge reduction and solubility were 35% and 20.4%, respectively for 3 months. By crystallization, phosphorus was successfully removed from the solubilized sludge as an apatite and its average removal efficiency was 80.2%. When solubilzed sludge was appled into the anaerobic reactor of KSMBR process as an external carbon source, the average removal efficiency of the total phosphorus was improved up to 40%. Therefore, sludge reduction process proposed is thought to be applied onto phosphorus recovery and an external carbon source as well as sludge reduction.

하수처리장에서 발생하는 고농축 잉여슬러지의 열적가용화 특성에 관한 연구

김은혁,박명수,구슬기 유기성자원학회 2022 유기물자원화 Vol.30 No.4

The current environmental problem is that environmental pollution is accelerating due to the generation of large amounts of waste and indiscriminate consumption of energy. Fossil fuels, a representative energy production fuel, are burned in the process of producing energy, generating a large amount of greenhouse gases and eventually causing climate change. In addition, the amount of waste generated worldwide is continuously increasing, and environmental pollution is occurring in the process of waste treatment. One of the methods for simultaneously solving these problems is the energy recovery from and reduction of organic wastes. Sewage sludge generated in sewage treatment plants has been treated in various ways since ocean disposal was completely prohibited, but the amount generated has been continuously increasing. Since the sewage sludge contains a large amount of organic materials, it is desirable to recover energy from the sewage sludge and reduce the final discharged waste through anaerobic digestion. However, most of the excess sludge is a mass of microorganisms used in sewage treatment, and in order for the excess sludge to be anaerobically digested, the cell walls of the microorganisms must be destroyed first, but it takes a lot of time to destroy the cell walls, so high rates of biogas production and waste reduction cannot be achieved only by anaerobic digestion. Therefore, the pre-treatment process of solubilizing excess sludge is required, and the thermal solubilization process is verified to be the most efficient among various solubilization methods, and high rates of biogas production and waste reduction can be achieved by anaerobic digestion after destroying cell walls the thermal solubilization process. In this study, when pretreating TS 10% thickened excess sludge through a thermal solubilization system, a study was conducted on solubilization characteristics according to retention time and operating temperature variables. The experimental variables for the retention time of the thermal solubilization system were 30 minutes, 60 minutes, 90 minutes, and 120 minutes, respectively, while the operating temperature was fixed at 160°C. The soulbilization rates calculated through TCOD and SCOD derived from the experimental results increased in the order of 12.11%, 20.52%, 28.62%, and 31.40%, respectively. And the variables according to operating temperature were 120°C, 140°C, 160°C, 180°C, and 200°C, respectively, while the operating retention time was fixed at 60 minutes. And the solubilization rates increased in the order of 7.14%, 14.52%, 20.52%, 40.72%, and 57.85%, respectively. In addition, TS, VS, T-N, T-P, NH4 +-N, and VFAs were analyzed to evaluate thermal solubilization characteristics of thickened excess sludge. As a result, in order to obtain 30% or more solubilization rate through thermal solubilization of TS 10% thickened excess sludge, 120 minutes of retention time is required when the operating temperature is fixed to 160°C, and 170°C or more of operating temperature is needed when the operating time is fixed to 60 minutes. 현대의 환경문제는 다량의 폐기물의 발생과 무분별한 에너지의 소비로 인한 환경오염이 가속화 되고 있다는것이다. 대표적인 에너지 생산 연료인 화석연료는 에너지를 생산하는 과정에서 연소가 이루어져 다량의 온실가스가발생하고 최종적으로 기후변화를 야기한다. 또한 전 세계적으로 발생하는 폐기물의 양도 지속적으로 증가하고있으며 처리하는 과정에서 환경오염이 발생하고 있다. 이와 같은 문제들을 동시에 해결하기 위한 방법 중 하나는유기성 폐기물의 에너지화 및 감량화이다. 하수처리장에서 발생하는 하수슬러지는 해양매립이 전면 금지된 이후로 다양하게 처리되고 있으나, 그 발생량은지속적으로 증가하는 추세이다. 하수슬러지는 유기물을 다량 함유하고 있어 혐기소화를 통하여 하수슬러지를 에너지화 하고 최종 배출되는 폐기물을 감량화 하는 것이 바람직하다. 하지만, 잉여슬러지의 경우 대부분이 하수처리에이용되었던 미생물 덩어리로써 잉여슬러지가 혐기성소화 되기 위해서는 먼저 미생물의 세포벽이 파괴되어야 하는데세포벽 파괴에는 많은 시간이 요구되기 때문에 혐기성 소화 과정만으로는 높은 바이오가스 생산율이나 폐기물감량율을 달성할 수 없다. 따라서 잉여슬러지를 가용화하는 전처리 공정이 필요하며, 여러 가지 가용화 공법 중에서열적 가용화 공정이 가장 효율적인 것으로 검증되었고, 혐기성소화 공정의 전처리 과정으로써 열적가용화 공정을이용하여 잉여슬러지에 포함된 세포벽을 파괴한 후 전처리 된 잉여슬러지를 혐기성소화 함으로써 높은 바이오가스생산율과 폐기물 감량율을 달성할 수 있다. 본 연구에서는 열적 가용화장치를 통하여 TS 10%의 농축 잉여슬러지를 전처리하는데 있어서 체류시간 및 운전온도변수에 따른 가용화 특성에 대한 연구를 수행하였다. 열적 가용화장치의 체류시간에 대한 실험변수는 운전온도를160 ℃로 고정한 상태에서 각각 30분, 60분, 90분, 120분이었다. 실험 결과로 도출된 TCOD와 SCOD를 통해 계산된가용화율은 각각 12.11%, 20.52%, 28.62%, 31.40% 순으로 증가하였다. 또한, 운전온도에 따른 변수는 반응시간을60분으로 고정한 상태에서 각각 120°C, 140°C, 160°C, 180°C, 200°C였으며 가용화율은 각각 7.14%, 14.52%, 20.52%, 40.72%, 57.85% 순으로 증가하였다. 이 외에 TS, VS, T-N, T-P, NH4 +-N, VFAs를 분석하여 농축 잉여슬러지를 대상으로하는 열적 가용화 특성에 대한 평가를 수행 했으며, 그 결과 TS 10%의 농축 잉여슬러지에 대한 열적 가용화를통하여 30% 이상의 가용화율을 얻기 위해서는 운전온도를 160°C로 고정할 경우 120분의 체류시간이 필요하며, 운전시간을 60분으로 고정할 경우 170°C 이상의 운전온도가 요구되어 진다.

산처리에 의한 정수슬러지 감량화

이병문,권재현,안규홍,이석헌,권대영 대한상하수도학회 2003 상하수도학회지 Vol.17 No.1

The acidic treatment of waterworks sludge released organic materials as well as inorganics such as Al, Fe and Mn. Through solubilization as mentioned above, the content of suspended solids reduced by 18% at final pH 3.5. It also increased thickening efficiency and dewaterability of sludge. However overdosing of H_2SO_4 made dewaterability deteriorated. It showed that the optimal condition of acidic treatment be as follows; 5.5㎖ dose of H_2SO_4(97%)/1 sludge, final pH 3.5 and 15minutes of reaction time. Under these conditions, reduction efficiencies of sludge through thickening and dewatering were 57% and 92.2% respectively and then 7.8% of raw sludge released as cake compared to 10.5% without acidic pre-treatment. Therefore, mass of dewatered cake decreased by 26% through acidic treatment. Water content of dewatered cake was reduced from 71% to 62% due to this treatment. The changes of sludge properties including particle size, zeta-potential and bound water by acidic treatment appear to be important keys in assesment of the improvement of sludge dewaterability.

Influence of the Thermochemical Sludge Pretreatment on the Nitrification of A/O Reactor with the Removal of Phosphorus by Simultaneous Precipitation

Khac-Uan Do,J. Rajesh Banu,S. Kaliappan,ICK-TAE YEOM 한국생물공학회 2013 Biotechnology and Bioprocess Engineering Vol.18 No.2

In the present study, a laboratory scale anoxic/oxic (A/O) reactor is used for the removal of nutrient and sludge reduction. Phosphorus removal was achieved through simultaneous precipitation, and sludge production was reduced through thermochemical pretreatment. The main objective of the study was to investigate the influence of sludge pretreatment on the nitrification rate. Total phosphorus in the effluent was maintained around 0.5 ~1.0 mg/L by simultaneous precipitation, using coagulant alum at 2.2 mole ratio. Before simultaneous precipitation,the nitrification rate of the A/O reactor was found to be 0.050 g N-NH4+/g MLVSS.d. The thermochemical sludge pretreatment began on the 120th day at pH 11 and 80oC. The initiation of sludge pretreatment brought about a significant reduction of the A/O reactor nitrification rate,which fell to 0.038 g N-NH4+/g MLVSS/day. The effect of sludge pretreatment was reflected in the reduction of the nitrogen removal efficiency from 85 to 74%. Recycling of the thermochemically pretreated sludge accounted for 57%sludge reduction, which had an adverse influence on the nitrification rate of the system.

옥수수 대 산발효액을 이용한 혐기성 병합공정에서 C/N비율이 바이오가스 생산과 슬러지 감량에 미치는 영향

최희정 ( Hee-jeong Choi ) 한국수처리학회 2020 한국수처리학회지 Vol.28 No.2

The purpose of this study was to find the optimal C/N ratio for sludge reduction and biogas production through a two-step anaerobic co-digestion process of acidogenically fermented maize stalk broth (AFMB) with sewage sludge. AFMB was prepared as follows: Crushed maize stalk were mixed with 20% (v/v) tap water. The mixture was put into a 10-L cylindrical reactor and anaerobically fermented at 100 rpm and 55 ± 2 °C without pH control (initial pH was 7.2 ± 0.3) to improve fermentation efficiency of maize stalks. The ratio of C/N was prepared to 5.32, 8.62, 12.27, 18.15, 24.43 and 30.75 using the mixing of AFMB and sewage sludge for sludge reduction and biogas production in the anaerobic co-digestion process. The highest total solid (TS) and volatile solid (VS) removal efficiency and biogas recovery was observed with C/N ratio of 18.15, which was found to be 58.13%, 67.85% and 1841.05 mL for TS, VS and biogas, respectively. Above C/N ratio of 24, the activation of microorganisms was inhibited by low pH, thereby TS, VS removal efficiency and biogas production were reduced. Therefore, in case of sludge reduction and biogas production in the anaerobic co-digestion process using AFMB, the optimum C/N ratio was recommended between 18-24. In addition, the production of biogas using AFMB in anaerobic co-digestion was determined a methane content of more than 70%, which opens the possibility of biogas production using AFMB.

기계적 처리와 금속촉매 오존산화에 의한 슬러지 감량화

윤상현,장현섭,이명주,황선진 경희대학교 2005 環境硏究 論文集 Vol.14 No.-

This research investigated the effect of mechanical pretreatment and ozone/catalytic oxidation on the reduction of sewage sludge. The pretreatment process was carried out to enhance sludge solubilization. The degree of solubilization was evaluated based on the DR. TS 1∼4% sludge was treated by ball mil using glass beads of 1 mm in diameter with the 50% (v/v) zircon bead loading. TS 4% showed 4 times higher solubilization efficiency than that of untreated sludge. The combination of the mechanical pretreatment and ozone/catalytic oxidation(10 mg Mn/g TS) showed higher efficiency than ozone/catalytic oxidation. At the 40% solubilization efficiency of sludge achieved by using ball mill, combination treatment showed 3 times higher than control. Ozone/catalytic oxidation improved the solid reduction effectively in the lower pH, presumably due to a high production of OH radical.

Evaluation of Chloride Reduction in the Residue of Carbonization from the Mixture of Wood Waste and Sewage Sludge

Hyeong-Jin Choi,Seung-Whee Rhee 한국폐기물자원순환학회 2015 한국폐기물자원순환학회 학술대회 Vol.2015 No.05

According to the quality standards of the BIO-SRF(Bio-Solid Fuel Products) in Act on the Promotion of Saving and Recycling of Resources enforcement regulations, chloride is regulated to less than 0.5wt.%. The reason why chloride was regulated may generate HCl and dioxin when bio-solid fuel was burnt. Chloride and chloride compounds can be presented the characteristic of corrosiveness. These materials is reacted with iron to produce ferric chloride. Ferric chloride is oxidized to ferric oxide and ferric oxide can cause a pipe corrosion to short boiler life in combustion facility. There are several reactions to reduce Cl concentration in organic wastes and some wastes can be used in nucleophile reaction as reductive agents. Nucleophile(Nu) material can be represented by phosphate, nitrate, sulfate etc. Nu materials can substitute them for chlorine-based compounds(X-: Cl-, Br-, I-). Nu materials can reduce the harmfulness and chlorine concentration by substituting them for chlorine-based compounds of the solid fuel product produced by carbonization. In order to produce solid fuel product from organic wastes, carbonization among pyrolysis processes is suitable because nucleophile reaction should be an endothermic reaction, which heat must be entered to solid fuel product from outside. In this study, sewage sludge is used as a reductive agent to evaluate the characteristics of the reduction reaction in carbonization process because a large amount of Nu material is contained in sewage sludge. In order to evaluate the effect of Nu materials to control chloride in the residue of carbonization, waste wood mixed with sewage sludge was used in carbonization process.

무기성 순환자원의 수소 활성화 및 이산화탄소 분해

고재철(Jae Churl Ko),전제열(Jae Youl Jeon),박준석(Joon Seok Park),박영구(Young Koo Park) 한국유화학회 2008 한국응용과학기술학회지 Vol.26 No.4

This research was conducted to estimate the characteristics of carbon dioxide decomposition using an inorganic sludge. The inorganic sludge was composed of high amount (66.8%) of Fe2O3. Hydrogen could be reduced with 0.247, 0.433, 0.644, and 0.749 at 350, 400, 450, and 500℃, respectively. The carbon dioxide decomposition rates at 250, 300, 350, 400, 450, and 500℃ were 32, 52, 35, 62, 75, and 84%, respectively. High temperature led to high reduction of hydrogen and better decomposition of carbon dioxide. The specific surface area of the sludge after hydrogen reduction was higher than that after carbon dioxide decomposition. The specific surface area of the sludge was more decreased with increasing of temperature.

Evaluation of Chloride Reduction in the Residue of Carbonization from the Mixture of Wood Waste and Sewage Sludge

( Hyeong-jin Choi ),( Seung-whee Rhee ) 한국폐기물자원순환학회(구 한국폐기물학회) 2015 한국폐기물자원순환학회 춘계학술발표논문집 Vol.2015 No.-

According to the quality standards of the BIO-SRF(Bio-Solid Fuel Products) in Act on the Promotion of Saving and Recycling of Resources enforcement regulations, chloride is regulated to less than 0.5wt.%. The reason why chloride was regulated may generate HCl and dioxin when bio-solid fuel was burnt. Chloride and chloride compounds can be presented the characteristic of corrosiveness. These materials is reacted with iron to produce ferric chloride. Ferric chloride is oxidized to ferric oxide and ferric oxide can cause a pipe corrosion to short boiler life in combustion facility. There are several reactions to reduce Cl concentration in organic wastes and some wastes can be used in nucleophile reaction as reductive agents. Nucleophile(Nu) material can be represented by phosphate, nitrate, sulfate etc. Nu materials can substitute them for chlorine-based compounds(X-: Cl^-, Br^-, I^-). Nu materials can reduce the harmfulness and chlorine concentration by substituting them for chlorine-based compounds of the solid fuel product produced by carbonization. In order to produce solid fuel product from organic wastes, carbonization among pyrolysis processes is suitable because nucleophile reaction should be an endothermic reaction, which heat must be entered to solid fuel product from outside. In this study, sewage sludge is used as a reductive agent to evaluate the characteristics of the reduction reaction in carbonization process because a large amount of Nu material is contained in sewage sludge. In order to evaluate the effect of Nu materials to control chloride in the residue of carbonization, waste wood mixed with sewage sludge was used in carbonization process.