Characteristics of phenol degradation by immobilized activated sludge

Sun-Il Kim,Sook-Young Lee,전영남 한국공업화학회 2009 Journal of Industrial and Engineering Chemistry Vol.15 No.3

The effects of various factors involved in phenol degradation through an immobilized activated sludge with a photo-crosslinked resin were investigated. The immobilized activated sludge showed a higher relative activity of phenol degradation across a broader range of pH than free activated sludge. A higher rate of phenol degradation was observed when the bead size was smaller. The phenol degradation in the free activated sludge was inhibited at the 3000 mg/L of phenol, while that in the immobilized activated sludge was maintained at the same concentration for 28 h without any inhibition. The degradation rates of phenol were not directly proportional to the increasing amount of immobilized bead dosage, but the phenol degradation was completed in a shorter time than that for the free activated sludge. For the repeated reaction of immobilized activated sludge, the relative activity is increased up to eight times after seven repeated initial cycles. Continued treatment of immobilized activated sludge showed more than 95% of phenol removal efficiency under a loading rate of 5.59 kg-phenol/(m3 d), which is twice as large as the loading rate for the free activated sludge.

Characteristics of phenol degradation by immobilized activated sludge

Lee, Sook-Young,Chun, Young-Nam,Kim, Sun-Il Elsevier 2009 Journal of industrial and engineering chemistry Vol.15 No.3

<P><B>Abstract</B></P><P>The effects of various factors involved in phenol degradation through an immobilized activated sludge with a photo-crosslinked resin were investigated. The immobilized activated sludge showed a higher relative activity of phenol degradation across a broader range of pH than free activated sludge. A higher rate of phenol degradation was observed when the bead size was smaller. The phenol degradation in the free activated sludge was inhibited at the 3000mg/L of phenol, while that in the immobilized activated sludge was maintained at the same concentration for 28h without any inhibition. The degradation rates of phenol were not directly proportional to the increasing amount of immobilized bead dosage, but the phenol degradation was completed in a shorter time than that for the free activated sludge. For the repeated reaction of immobilized activated sludge, the relative activity is increased up to eight times after seven repeated initial cycles. Continued treatment of immobilized activated sludge showed more than 95% of phenol removal efficiency under a loading rate of 5.59kg-phenol/(m<SUP>3</SUP>d), which is twice as large as the loading rate for the free activated sludge.</P>

Biostimulating Effects of Disintegrated Waste Activated Sludge on Soil Enzyme Activities

Fatma Olcay Topac,Canan Etyam 대한토목학회 2021 KSCE JOURNAL OF CIVIL ENGINEERING Vol.25 No.7

Sludge disintegration methods are used in a variety of applications to enhance sludge characteristics or bring about a reduction in solid content of sludge. Hydrodynamic cavitation is one of the mechanical disintegration methods used on waste-activated sludge, and its efficiency has been investigated in recent years. In this study, the possible use of waste-activated sludge disintegrated by hydrodynamic cavitation and chemically assisted hydrodynamic cavitation as a soil amendment was evaluated by an incubation procedure. Possible biostimulating effects were assessed by monitoring the variations in soil enzyme activities. The obtained results indicated that sludge solubilization was effectively performed with respect to soluble chemical oxygen demand, soluble total Kjeldahl nitrogen and soluble total phosphorus. According to the incubation study, the biostimulating/bioremediating properties of waste-activated sludge were significantly improved by the applied methods. Especially after a 60-day incubation period, the levels of urease, alkaline phosphatase, β-glucosidase and dehydrogenase activities in soils applied with a high dose of disintegrated sludge were significantly higher than the levels in raw sludge-amended soils. Consequently, it is thought that mechanically and chemically disintegrated waste-activated sludge with reduced numbers of indicator bacteria can be considered as a way of soil amendment to rehabilitate the quality of environmentally stressed soils.

Disintegration of excess activated sludge by hydrogen peroxide oxidation

Kim, Tak-Hyun,Lee, Sang-Ryul,Nam, Youn-Ku,Yang, Jeongmok,Park, Chulhwan,Lee, Myunjoo Elsevier 2009 Desalination Vol. No.

<P><B>Abstract</B></P> <P>As the result of a conventional wastewater treatment such as activated sludge process, an excess sludge is produced and must be disposed of safely. Recently, increased attention has been given to a minimization of waste sludge in a wastewater treatment process. In this study, hydrogen peroxide oxidation was applied for an excess activated sludge reduction and an alkaline pretreatment method was used to enhance the efficiency of hydrogen peroxide oxidation of sludge. Sludge particle disintegration by hydrogen peroxide oxidation was confirmed through the evaluations of total solid concentration and particle size distribution. The solubility (SCOD/TCOD) of sludge was increased, while the viscosity was decreased with hydrogen peroxide oxidation and alkaline hydrolysis. The settleability of sludge was improved. When alkaline hydrolysis was applied as a pretreatment for hydrogen peroxide oxidation, the sludge particle disintegration, viscosity decrease, and settleability improvement were accelerated. From the results of this experiment, it can be concluded that hydrogen peroxide oxidation combined with alkaline pretreatment was useful for an excess sludge reduction.</P>

Wastewater treatment from synthetic wastewater by immobilized Chlorella vulgaris and suspended activated sludge: effects of different ratios

( Ghulam Mujtaba ),( Rizwan Muhammad ),이기세 한국공업화학회 2015 한국공업화학회 연구논문 초록집 Vol.2015 No.1

The co-culture system, composed of microalgae and bacteria, is considered as an alternative biosystem that can sustainably be used to remove inorganic nutrients (nitrogen and phosphorous) and COD. Immobilized C. vulgaris and suspended activated sludge were used in 1-L bubble column photobioreactors with 600 mL culture volume for the removal of nutrients. Three different ratios of C. vulgaris and activated sludge (such as, 1:1, 1:2, and 2:1) were applied to check the relative performance. Co-culture system, in any given ratio, removed significantly more nitrogen, phosphorous, and COD as compared to conventional system (activated sludge only). There was no significant difference in removing phosphorous and COD under three respected ratios. However, comparatively, most nitrogen was reduced in 2:1 of C. vulgaris and activated sludge. Both the C. vulgaris and bacteria present in activated sludge were increased during the treatment time.

정수슬러지 유래 흡착제와 첨착활성탄의 암모니아 및 포름알데히드 기체 흡착 성능 비교

이철호 ( Choul Ho Lee ),박나영 ( Nayoung Park ),김고운 ( Goun Kim ),전종기 ( Jong-ki Jeon ) 한국공업화학회 2016 공업화학 Vol.27 No.1

In this study, a pellet-type adsorbent was prepared by using the water-treatment sludge as a raw material, and its physical and chemical properties were analyzed through N2-adsorption, XRD, XRF, and NH3-TPD measurements. Adsorption performance for gaseous ammonia and formaldehyde was compared between the pellet-type adsorbents prepared from water-treatment sludge and the impregnated activated carbon. Although the surface area and pore volume of the pellet-type adsorbent produced from water- treatment sludge were much smaller than those of the impregnated activated carbon, the pellet-type adsorbent produced from water-treatment sludge could adsorb ammonia gas even more than that of using the impregnated activated carbon. The pellet-type adsorbent prepared from water-treatment sludge showed a superior adsorption capacity for ammonia which can be explained by chemical adsorption ascribed to the higher amount of acid sites on the pellet-type adsorbent prepared from water-treatment sludge. In the case of formaldehyde adsorption, the impregnated activated carbon was far superior to the adsorbent made from the water-treatment sludge, which can be attributed to the increased surface area of the impregnated activated carbon.

총인 시설계 슬러지를 이용한 혐기성 소화 슬러지에서 재용출된 인의 제거

서정인 ( Jung-in Suh ),윤호석 ( Ho-seok Yoon ),조관훈 ( Kwan-hoon Cho ),권대원 ( Dae-won Kwon ) 한국수처리학회 2016 한국수처리학회지 Vol.24 No.3

In this study, the thickener sludge(PS-sludge) generated at total phosphorus(T-P) removal process was introduced into anaerobic digested activated sludge to examine the role of PS-sludge in immobilizing phosphorus and also in improving dewaterability of the mixed sludge. Maximum absorption capacity of phosphorus from the Langmuir isotherm plot was 9.3 mg/g-sludge(dry wt.) for PS-sludge. Experimental results observed T-P removal of 87% using a PS-sludge concentration of 1.66% TS(total solids), and the simultaneous decrease in COD(chemical oxygen demand). However the use of PS-sludge resulted in the deterioration of the dewaterability of mixed sludge by increasing the SRF(specific resistance to filtration). The results indicated that PS-sludge can further be used as absorbent media for T-P removal from the reject water, despite of the deterioration of the sludge dewaterability.

하수슬러지 활성탄의 벤젠 흡착특성

김종문(Jong-Moon Kim),정찬교(Chan-Kyo Chung),이택룡(Taek-Ryong Lee),민병훈(Byong-Hun Min),김형진(Hyung-Jin Kim),권영식(Young-Shik Kwon) 한국청정기술학회 2009 청정기술 Vol.15 No.4

Numerical simulation of secondary clarifier with activated sludge and suction lift removal system: Modified Casson model and sludge withdrawing sensitivity analysis

Mehrzad Shams,Muhammad Reza Saffarian,Mohammad Hossein Hamedi 한국화학공학회 2010 Korean Journal of Chemical Engineering Vol.27 No.4

A computational fluid dynamics model that predicts the sedimentation of activated sludge in a circular secondary clarifier with activated sludge is developed. The axisymmetric single-phase flow is simulated by using a CFD code that has been written with Intel Visual Fortran. First, sludge withdrawing by suction-lift in the near-bottom region of the clarifier is simulated using suction at the bottom of clarifier. The flow and settling processes are simulated using k-ε turbulence model on a two-dimensional and orthogonal grid. A convection–dispersion equation that is extended to incorporate the sedimentation of activated sludge in the field of gravity is used. The computational domain includes the sludge blanket where the viscosity is affected by the rheological behavior of the sludge. Experimental data provided by Weiss et al. show that the relationship between shear stress and shear rate follows the Casson law for the shear rates lower than 50 s−1. Plastic viscosity of activated sludge is not removed from the concentration diffusion, so using regular non-Newtonian models leads to overestimation of blanket height. Modified Casson model is introduced to overcome the blanket height overestimation problem. Results show that the local sludge distribution in the clarifier has excellent agreement with concentration profile measurements of Weiss et al., for different treatment plant loadings. Alternative sludge withdrawing methods include withdrawing from pipes position at the bottom of clarifier and withdrawing by using sink terms in governing equations are used. Results show that the first withdrawing method gives less error comparing to these withdrawing methods.

Enhancement of Volatile Fatty Acids Removal by a Co-culture of Microalgae and Activated Sludge

Thi Hiep Han,Shan Zhang,조무환,황선진 대한토목학회 2017 KSCE JOURNAL OF CIVIL ENGINEERING Vol.21 No.6

The synergistic effects of a co-culture of Chlorella vulgaris (C. vulgaris) and activated sludge in Volatile Fatty Acids (VFAs) treatment were examined by constructing and comparing the performance of the three reactors (only algae, only activated sludge, coculture). As a result, the addition of the activated sludge stimulated the growth of C. vulgaris up to 2.6-fold, even though the initial algae concentration in the co-culture was only 30% of that in the only algae reactor. The treatment efficiency, which was indicated by the degradation of both the VFAs and nutrients, increased due to the symbiotic relationship of the co-culture of C. vulgaris and activated sludge. For the co-culture of algae and activated sludge, the propionate removal rate was enhanced by approximately 29.5- fold and 2.2-fold, respectively, compared to only algae and only sludge; the butyrate removal rate was also enhanced 6-fold and 1.5- fold, respectively. Both the and removal rate of the reactor with the co-culture was approximately 2 times higher than that of the reactor with the only algae and only sludge. Within 88 h, the removal efficiency of the co-culture reactor reached 98.2%, whereas the removal efficiency was 59.3% and 49.8% for only algae and only sludge reactor, respectively.