Effect of Operational Parameters on the Removal of Particulate Chemical Oxygen Demand in the Activated Sludge Process

Abstract The quality of a treated effluent changes when there is a sudden variation in the influent flow to the wastewater treatment plant during dry, rain, and storm weather conditions. In this study, various influent flow conditions in an activated sludge process are considered that affect the sensitivity of effluent variables such as chemical oxygen demand (COD), biological oxygen demand (BOD), nitrate nitrogen (SNO), ammonical nitrogen (SNH), and total nitrogen (TN) with respect to varying internal recycle flow rate (Qa), sludge recycle flow rate (Qr), sludge wastage flow rate (Qw) and oxygen transfer rate co-efficient of aerobic tanks (KLa(3,4,5)). The analysis has been carried out based on benchmark simulation model no.1 (BSM 1) plant layout which comprises of two models namely activated sludge model no.1 (ASM 1) and simple one dimensional (Simple 1-D) Takacs model. Based on the present analysis, it is observed that the changes in influent flow rate have larger impact on the effluent variables. This variation can be subdued by introducing additional tanks to smoothen the perturbations or using internal recycle rate from the fifth tank in order to maintain the flow around the optimal influent flow rate. The sludge wastage rate has a greater impact on all effluent variables except nitrogenous variables during maximum flow conditions.

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Effect of important operational parameters on performance of coarse pore filtration activated sludge process

Water Science & Technology ◽

10.2166/wst.2002.0246 ◽

2002 ◽

Vol 46 (9) ◽

pp. 229-236 ◽

Cited By ~ 19

Author(s):

M.R. Alavi Moghaddam ◽

H. Satoh ◽

T. Mino

Keyword(s):

Activated Sludge ◽

Aeration Tank ◽

Activated Sludge Process ◽

Operational Parameters ◽

Solid Retention Time ◽

Effluent Quality ◽

Membrane Pores ◽

Filtration Membrane ◽

Operation Pressure ◽

Filter Clogging

A coarse pore filter can be applied inside the aeration tank instead of sedimentation tank for liquid separation from the sludge. It has pores, which are irregular in shape, and much bigger than micro-filtration membrane pores in size. The objective of the study was to investigate the effect of important operational parameters such as flux, aeration intensity, and solid retention time (SRT) on the performance of the coarse pore filtration activated sludge process. The effect of these parameters was studied in laboratory scale experiments. It was found that the flux had a significant role in the effluent quality of this system. The effluent SS and turbidity were not changed significantly at different aeration intensities. Three SRTs, 10, 30 and longer days (without excess sludge) were used for three reactors to check the effect of this parameter on the system performance. The results of the reactors with SRTs about 10 and 30 days have shown very good effluent quality without any filter clogging for more than 4 months operation. For the reactor with long SRT, the filter clogging was observed after about 80 days of operation, which caused the increase of the operation pressure and deterioration in the effluent quality for a few days.

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Degradation of Nonylphenol Polyethoxylates and its Microflora Structure in an Anoxic-Oxic Activated Sludge Process

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.610-613.331 ◽

2012 ◽

Vol 610-613 ◽

pp. 331-336

Author(s):

Yuan Hua Xie ◽

Tong Zhu ◽

Xiao Jiang Liu ◽

Hui Liu ◽

Jin Han

Keyword(s):

In Situ Hybridization ◽

Activated Sludge ◽

Removal Efficiency ◽

Gel Electrophoresis ◽

Loading Rate ◽

Denaturing Gradient Gel Electrophoresis ◽

Oxygen Demand ◽

Activated Sludge Process ◽

Gradient Gel Electrophoresis

An anoxic-oxic activated sludge process (AOASP) was carried out to degrade nonylphenol polyethoxylates (NPEOs). The carbon source in influent was replaced stepwise by a mixture of nonylphenol decaethoxylate (M-NP10EO). The 2nd-derivative UV-spectrometry was applied to determine the total amount of M-NP10EO in water samples. Chemical oxygen demand (COD) removal efficiency achieves about 85% under the highest M-NP10EO loading rate, and M-NP10EO removal efficiency is about 80%. Denaturing gradient gel electrophoresis (DGGE) results of activated sludges show that the microbe species decrease but gradually stabilize with the increase of M-NP10EO concentration in influent. Fluorescence in situ hybridization (FISH) results of activated sludges showe that the dominant microflora under the highest M-NP10EO loading rate is β-Proteobacteria (35%), followed by α-Proteobacteria (15%), γ-Proteobacteria (5%) and Actinobateria (4%).

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POTENSI SELULASE DAN PENGARUH LAJU PEMBEBANAN PADA EFEKTIVITAS PENGOLAHAN AIR LIMBAH KERTAS PROSES LUMPUR AKTIF (POTENTIAL OF CELLULASE AND EFFECT OF LOADING RATE ON TREATMENT OF PAPER WASTEWATER OF ACTIVATED SLUDGE PROCESS)

JURNAL SELULOSA ◽

10.25269/jsel.v6i02.92 ◽

2016 ◽

Vol 6 (02) ◽

Author(s):

Andri Taufick Rizaluddin ◽

Sri Purwati

Keyword(s):

Activated Sludge ◽

Residence Time ◽

Industrial Wastewater ◽

Organic Pollutant ◽

Continuous Process ◽

Oxygen Demand ◽

Activated Sludge Process ◽

Effluent Quality ◽

Paper Wastewater ◽

Enzyme Dosage

As the effluent quality standards for industrial wastewater are becoming more stringent, it is important for the industry to improve their wastewater treatment efficiency. The research about potential of cellulase application in the activated sludge process has been done. Theoritically, the addition of cellulase was required to support the activity of microorganism on the activated sludge. Since cellulose is the major organic pollutant component in the wastewater, it was expected that cellulase addition could improve the performance of activated sludge process. The experiments were conducted in a continuous process and consisted of two treatments which were with and without activated sludge at about 2400 mg MLVSS/L. The variations in each treatment were the enzyme dosages of 0; 0.2; 0.5; and 0.7 unit/g COD, and the residence time of 4, 8, 12, and 24 hours. The experiment result showed that the addition of cellulase can increase COD and BOD reduction compared to the treatment without enzymes. The highest COD reduction increment was 7.9% at the enzyme dosage of 0.2 unit/g COD and the residence time of 4 hours, while the highest BOD reduction increment was 14.6% at the same enzyme dosage and residence time. In conclusion, celullase application can be combined with the activated sludge process which will be effective in the high load organic wastewater. ABSTRAKDengan semakin ketatnya baku mutu air limbah, peningkatan efisiensi dalam pengolahan limbah menjadi sangat penting bagi industri. Penelitian ini dilakukan untuk mengetahui potensi selulase dan pengaruh laju pembebanan pada efektifitas pengolahan air limbah kertas sistem lumpur aktif. Secara teori, penambahan selulase diperlukan untuk membantu aktivitas mikroorganisme lumpur aktif. Dengan adanya kandungan selulosa sebagai komponen utama pencemar organik dalam air limbah, penambahan selulase diharapkan dapat meningkatkan kinerja proses lumpur aktif. Percobaan dilakukan dengan proses kontinyu yang terdiri dari dua perlakuan, yaitu tanpa dan dengan lumpur aktif pada MLVSS sekitar 2400 mg/L. Variasi pada setiap perlakuan berupa variasi dosis selulase (0; 0,2; 0,5; dan 0,7 unit/g COD) dan variasi laju pembebanan dengan mengatur waktu tinggal 4, 8, 12, dan 24 jam. Hasil percobaan menunjukkan bahwa perlakuan lumpur aktif dengan penambahan selulase dapat menghasilkan peningkatan reduksi COD dan BOD bila dibandingkan perlakuan tanpa menggunakan selulase. Peningkatan reduksi COD tertinggi mencapai 7,9% dengan perlakuan selulase dosis 0,2 unit/g COD dan waktu tinggal 4 jam, sedangkan peningkatan reduksi BOD tertinggi mencapai 14,6%. Perlakuan selulase dapat dikombinasikan dengan proses lumpur aktif yang berjalan efektif pada waktu tinggal yang lebih singkat atau pada beban tinggi.Kata kunci: selulase, lumpur aktif, chemical oxygen demand, biological oxygen demand

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Systematic Modeling of Municipal Wastewater Activated Sludge Process and Treatment Plant Capacity Analysis Using GPS-X

Sustainability ◽

10.3390/su12198182 ◽

2020 ◽

Vol 12 (19) ◽

pp. 8182

Author(s):

Nuhu Dalhat Mu’azu ◽

Omar Alagha ◽

Ismail Anil

Keyword(s):

Activated Sludge ◽

Suspended Solids ◽

Systematic Approach ◽

Municipal Wastewater ◽

Treatment Plant ◽

Oxygen Demand ◽

Plant Performance ◽

Capacity Analysis ◽

Activated Sludge Process ◽

Effluent Quality

Mathematical modeling has become an indispensable tool for sustainable wastewater management, especially for the simulation of complex biochemical processes involved in the activated sludge process (ASP), which requires a substantial amount of data related to wastewater and sludge characteristics as well as process kinetics and stoichiometry. In this study, a systematic approach for calibration of the activated sludge model one (ASM1) model for a real municipal wastewater ASP was undertaken in GPS-X. The developed model was successfully validated while meeting the assumption of the model’s constant stoichiometry and kinetic coefficients for any plant influent compositions. The influences of vital ASP parameters on the treatment plant performance and capacity analysis for meeting local discharge limits were also investigated. Lower influent chemical oxygen demand in mgO2/L (COD) could inhibit effective nitrification and denitrification, while beyond 250 mgO2/L, there is a tendency for effluent quality to breach the regulatory limit. The plant performance can be satisfactory for handling even higher influent volumes up to 60,000 m3/d and organic loading when Total Suspended Solids/Volatile Suspended Solids (VSS/TSS) and particulate COD (XCOD)/VSS are maintained above 0.7 and 1, respectively. The wasted activated sludge (WAS) has more impact on the effluent quality compared to recycle activated sludge (RAS) with significant performance improvement when the WAS was increased from 3000 to 9000 m3/d. Hydraulic retention time (HRT) > 6 h and solids retention time (SRT) < 7 days resulted in better plant performance with the SRT having greater impact compared with HRT. The plant performance could be sustained for a quite appreciable range of COD/5-day Biochemical Oxygen Demand (BOD5 in mgO2/L) ratio, Mixed Liquor Suspended Solid (MLSS) of up to 6000 mg/L, and when BOD5/total nitrogen (TN) and COD/TN are comparatively at higher values. This work demonstrated a systematic approach for estimation of the wastewater treatment plant (WWTP) ASP parameters and the high modeling capabilities of ASM1 in GPS-X when respirometry tests data are lacking.

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Effect of chemical oxygen demand load on the nitrification and microbial communities in activated sludge from an aerobic nitrifying reactor

Canadian Journal of Microbiology ◽

10.1139/cjm-2018-0599 ◽

2020 ◽

Vol 66 (1) ◽

pp. 59-70

Author(s):

Dan Li ◽

Xihong Liang ◽

Zhengwei Li ◽

Yao Jin ◽

Rongqing Zhou ◽

...

Keyword(s):

Activated Sludge ◽

Chemical Oxygen Demand ◽

Microbial Communities ◽

High Throughput Sequencing ◽

Oxygen Demand ◽

Nitrification Rate ◽

Culture Time ◽

Degradation Rates ◽

Significant Difference ◽

Over Time

In this study, we explored the effect of chemical oxygen demand (COD) load on the nitrification and microbial communities in activated sludge isolated from an aerobic nitrifying tank. The activated sludge was cultured in three different COD groups: L-COD, 200 mg/L; M-COD, 1200 mg/L; H-COD, 4200 mg/L. The results indicated that the COD exerts a negligible effect on the nitrogen removal ability within the first 24 h. However, the nitrification rate decreased with culture time; the ammonium degradation rates were found to be 80.26%, 57.56%, and 43.43% at 72 h in the three COD groups, respectively. These values correspond to decreases of 19.40%, 41.83%, and 51.48%, respectively, in relation to those observed at 24 h. The activated sludge in the different COD groups exhibited similar community compositions after 24 h, as assessed by Illumina high-throughput sequencing, while a significant difference in the relative abundances of some organisms occurred after 48 and 72 h. Proteobacteria was the main phylum, with a relative abundance of >51.45%. The genera Aridibacter, Paracoccus, Nitrospira, and Nitrosomonas were suppressed by COD load over time. This study may contribute to our knowledge about the nitrification ability and microbial communities in activated sludge at different COD load levels.

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The Implementation of Bulking Control in the Design of Activated Sludge Systems

Water Science & Technology ◽

10.2166/wst.1994.0342 ◽

1994 ◽

Vol 29 (7) ◽

pp. 193-202 ◽

Cited By ~ 13

Author(s):

Jiri Wanner

Keyword(s):

Activated Sludge ◽

Design Procedure ◽

Process Models ◽

Activated Sludge Process ◽

Operational Parameters ◽

Technological Parameters ◽

Factors Affecting ◽

Filamentous Microorganisms ◽

Biomass Retention ◽

Selection Mechanisms

The factors affecting the growth of most common filamentous microorganisms are discussed. In a design procedure the following factors should be considered: wastewater composition (readily and slowly biodegradable substrates, inoculation), biomass retention time, actual substrate concentration in reactor, operational parameters in reactor (DO and nutrients concentration, pH, temperature) and cultivation conditions. The configurations of activated sludge process supporting the growth of floc-formers are described. As general design methods and criteria for the design of bulking control systems are not available due to the complexity of selection mechanisms, the technological parameters from successful bulking control case histories are summarized. The possibilities of mathematical activated sludge process models for design purposes are evaluated.

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