• 상하수도학회지
• /
• 제32권2호
• /
• pp.89-96
• /
• 2018

This study aimed to investigate the feasibility of improving dewaterability and settleability of sewage sludge using coagulation sludge. When mixed with sewage sludge and coagulation sludge at 1:1 ratio, capillary suction time(CST) and specific resistance to filtration(SRF) decreased by about 56% and 68%, respectively. It is found that total solids(TS) and volatile solids(VS) of mixing sludge are increased by about 59% and 53%, respectively. Also, the turbidity of the mixing sludge supernatant was reduced from 99 to 16 NTU. It is observed that the mixing of sewage sludge and coagulation sludge at 1:1 showed better effect than using poly-aluminum chloride(PAC) coagulant at 25 mg/L.

• 환경위생공학
• /
• 제12권2호
• /
• pp.23-28
• /
• 1997

This study was conducted to know the possibility of reducing lime dosage by recycling sludge from bleaching wastewater lime coagulation settlement treatment at pulp mill process. In case of bleaching wastewater at the pulp mill process, when the lime dosage was increased, the removal efficiency of TSS(Total Suspended Solids) was increased, proportionally, but the organic removal efficiency was increased very slowly. It was concluded that sludge recycling at the lime coagulation settlement process was effective method to reduce the requirement of lime dosage. At the lime coagulation settlement process with sludge recycling, when the recycling number was increased, the organic removal efficiency was decreased, sharply. It was evaluated that the pH could be the basic standard for lime supplement by sludge recycling.

• 한국산학기술학회논문지
• /
• 제16권3호
• /
• pp.2314-2320
• /
• 2015

MBR (Membrane Bio-Reactor) 공정은 막 오염을 해결하기 위해 막대한 에너지 소비를 하는 공정으로 알려져 있다. 이를 해결하기 위한 일환으로 전기응집 기술을 MBR에 적용하는 시도가 보고되고 있다. 본 연구에서는 전류밀도를 변화시켜가며 활성슬러지의 막 여과를 수행하여 전기응집이 막 오염 저감에 미치는 영향과 메커니즘을 파악하고자 하였다. 활성슬러지 혼합액을 전기응집한 후 회분식교반셀로 분리 막의 여과성능을 평가하였다. 전류밀도(A/m2)를 10에서 40으로 증가시켰을 때 총 오염 저항 (Rc+Rf) 값이 18%에서 79%까지 감소하여 전기응집으로 인해 분리 막의 여과성능이 향상됨을 확인할 수 있었다. 전기응집 전후로 유기물 농도와 활성슬러지 입도분포 변화는 거의 일어나지 않았다. 여과 성능의 향상은 수산화알루미늄, Al(OH)3이 생성되어 막 표면에 부착되면서 오염물질이 쌓이게 됨을 방지하는 역할, 즉 dynamic membrane 으로 작용하였기 때문인 것으로 판단되었다.

• 청정기술
• /
• 제6권1호
• /
• pp.39-49
• /
• 2000

초고속응집침전공정(URC)은 가중응집제(WCA) 첨가와 슬러지 반송을 통해 floc의 침전 속도를 향상시키고, 입자표면의 흡착을 활성화하여 오염물을 보다 효율적으로 제거할 수 있으며, lamella plate를 포함하는 침전조를 이용하여 초기 우수 유출(CSO)과 같은 막대한 유량에 대하여 경제성 있는 침전조 수면적 부하를 획득할 수 있음을 확인하였다. 또한, 침전조의 최적설계를 위해 유체 유동장 모델을 이용한 모사가 수행되었으며, 공정에서 발생되는 슬러지에 대한 재활용 가능성을 평가하여 2차적 오염부하를 억제하기 위한 방안을 모색하였다.

• 한국물환경학회지
• /
• 제22권2호
• /
• pp.308-313
• /
• 2006

Charicteristics of piggery waste and treatment processing sludges for reuse were investigated. If it was thoroughly regulated in disinfectants, antibiotic substances and heavy metals, raw piggery waste can be gratified in criteria for fermentative compost (liquid) for flowers cultivation. Also, Because it is satisfied with various criteria of heavy metals and fertilizer contents for reuse except water content, primary pre-treatment sludge is very good material for composting. If provated goods on heavy metals are used in coagulation & dewatering process, coagulation & dewatering sludges are suitable for criteria of special waste regulation and by-product compost. This study proves that, if they are accomplished with suitable composting and mature process, piggery waste and processing sludges are free from microbiological problems as well as criteria of composting.

• 한국물환경학회지
• /
• 제22권4호
• /
• pp.687-694
• /
• 2006

Dewatering sludge using inorganic chemicals with polymer has been evaded for reuse on account of the risks of high heavy metals contained and soil acidification. Composting feasibility of coagulation & dewatering sludges produced from livestock waste treatment plant was investigated. The results of analysis prove that dewatering sludge is valuable matter with suitable elements for composting if high quality ferric chloride ($FeCl_3$) is used for coagulation & dewatering process. In pot-cultivation of harvestes, using effects of dewatering sludge improved with lime treatment was very effective. The results of pot-cultivation proved that harms of crops according to different acid tolerances were not detected. But it was not applied to crops with weak acid tolerance or greenhouse for free from gas damage. Also, Further studies and monitorings are necessary to use sludges because results of pot-cultivation were generated differently by characteristics of soil, nutrient demand of plants, mature degree of sludge, consecutive cultivation and etc.

• 한국환경보건학회지
• /
• 제33권1호
• /
• pp.68-74
• /
• 2007

The objective of this study is to examine the effect of the coagulation and homogenization in bulking sludge thickening of paper manufacturing plant using DAF(Dissolved Air Flotation) and gravitational sedimentation. The effects of parameters such as dosage of coagulant and homogenization time were examined. The results showed that DAF and sedimentation was affected aluminum sulfate and anion polymer coagulant differently. At the optimum dosage of aluminum sulfate, thickening efficiency of DAF and sedimentation process were increase 1.25 time and 2.02 time, respectively. At the optimum dosage of anion polymer coagulant, thickening efficiency of DAF process was increase 1.35 time, but thickening efficiency at sedimentation was 1.06 time. When anion polymer coagulant of 0.5 mg/l was added in DAF process, water content of sludge was decreased from 96.6% to 90.7% in dewatering process using Buchner funnel test device. After homogenization(20500 rpm, 10 min), Sauter mean diameter of sludge floc was decreased from 631 ${\mu}m$ to 427 ${\mu}m$, however increase of flotation efficiency by DAF was only 1.09 time.

• 청정기술
• /
• 제6권1호
• /
• pp.27-38
• /
• 2000

초고속응집침전공정(URC)은 가중응집제(WCA)를 첨가하고 슬러지를 반송시켜 응결핵으로서의 역할을 수행시킴으로서 floc의 성장속도를 향상시키고, 입자표면의 흡착을 활성화하여 유기물, 중금속, 인 등 수중에 존재하는 오염물을 보다 효율적으로 제거하며, 기존의 응집 공정에 비하여 침전성을 향상시킬 수 있다. 현재까지 하수처리장과 하천, 호소에서 수행된 URC pilot-test와 Jar-test의 결과를 비교 검토하여 가중 응집제와 반송 슬러지에 대한 오염물 제거특성에 대한 연구가 수행되었으며, 수자원의 재이용을 위한 가능성을 평가하였다.

• 상하수도학회지
• /
• 제26권4호
• /
• pp.579-589
• /
• 2012

To reduce extensive energy costs of the internal recycling for the purpose of denitrification in the advanced wastewater treatment, a post-treatment process using an electro-coagulation to treat nitrate in the secondary effluents is evaluated in this study. Removals of phosphorus and organics in the secondary effluents by the electro-coagulation were also evaluated to propose an alternative advanced wastewatert treatment process. A series of experiments of the electro-coagulation were carried out with the following 4 different samples: synthetic solution containing nitrate only, synthetic solution containing nitrate as well as phosphorus, secondary effluents from activated sludge cultivated in laboratory, and secondary effluents from real wastewater treatment plants. Removals of nitrate and phosphorus in the synthetic solution were 30 and 97 % respectively, which verified the feasibility of the process. Removals of nitrate, phosphorus and COD in the secondary effluents from the cultivated sludge in laboratory were 49, 90 and 19 % respectively. Removal efficiency of the total nitrogen, nitrrate, phosphorus and COD in the secondary effluent from real wastewater treatment plant were 50, 61, 98 and 80 % respectively. The removal of the total nitrogen was less than the nitrate as expected, which is due to the formation of ammonia nitrogen in the cathode. But the proposed scheme could be an energy saving and alternative process for the advanced wastewater treatment if further studies for the process optimization are carried out.

• 한국수처리학회지
• /
• 제26권6호
• /
• pp.73-80
• /
• 2018

In this study, the solids removal characteristics using T-P sludge generated from PACl coagulation were analyzed by laboratory scale and full scale experiment. As the amounts of T-P sludge injection into the raw sewage influent increased at the rate of 0, 1, 2, 3, 4 %, the suspended solids concentrations after 20 minutes setting test decreased to 210, 137, 91, 64, 43 mg/L, respectively. The filtration time required for dewatering test of the raw sewage influent decreased to 982, 728, 658, 581, 492 sec for 0, 1, 2, 3, 4% of T-P sludge injection, respectively. As the amounts of PACl coagulant into the effluent from final setting tank increased at 0, 10, 20, 30, 40 mg/L, the required filtration times for T-P sludge increased into 12.3, 41.7, 53.7, 67.2, 79.5 sec and the dewaterability of T-P sludge decreased. After T-P sludge returned into the primary settling tank on J-si sewage treatment plants, the effluent concentrations of COD, SS, T-N and T-P from primary settling tank into bioreactor decreased by 35.9, 27.9, 22.2, and 52.6% due to the coagulation effects of the T-P sludge. Finally, it was found that the return of T-P sludge into the primary settling tank could result into the sludge reduction having a lower water content of 3.03% p than in case of the only T-P sludge dehydration.