Kinetics of Removal of Particulate Chemical Oxygen Demand in the Activated-Sludge Process

2005 ◽  
Vol 77 (5) ◽  
pp. 437-446 ◽  
Author(s):  
Jose A. Jimenez ◽  
Enrique J. La Motta ◽  
Denny S. Parker
2017 ◽  
Vol 13 (2) ◽  
Author(s):  
B Vivekanandan ◽  
K Jeyannathann ◽  
A. Seshagiri Rao

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.


2012 ◽  
Vol 610-613 ◽  
pp. 331-336
Author(s):  
Yuan Hua Xie ◽  
Tong Zhu ◽  
Xiao Jiang Liu ◽  
Hui Liu ◽  
Jin Han

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%).


2012 ◽  
Vol 66 (10) ◽  
pp. 2243-2250 ◽  
Author(s):  
Wen-yi Dong ◽  
Xian-bing Zhang ◽  
Hong-jie Wang ◽  
Fei-yun Sun ◽  
Tong-zhou Liu

Three parallel biological anoxic filters (BaFs) were operated to investigate the denitrification kinetics of methanol, brewery wastewater and bakery wastewater. The experiment was conducted within the temperature range of 15–20 °C, with an influent nitrate and carbon dosage of 30 mg/L and 150 mg COD/L (COD: chemical oxygen demand). The denitrification efficiencies of brewery wastewater, bakery wastewater and methanol were 84, 66 and 74%, specific denitrification rates were 1.44, 1.11 and 1.24 kg NO3-N/m3 d, and total nitrogen (TN) removal rates were 74, 62 and 66%, respectively. The volatile attached solid (VAS) tests reveal that methanol has the minimum net biomass yield, so it needs the least carbon to nitrogen (expressed in COD to nitrate, C/N) ratio for complete denitrification. While the brewery wastewater and bakery wastewater need higher C/N ratio to remove all nitrate nitrogen, and they both may need pretreatment to remove phosphate when used as external carbon sources.


2016 ◽  
Vol 6 (02) ◽  
Author(s):  
Andri Taufick Rizaluddin ◽  
Sri Purwati

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


2020 ◽  
Vol 12 (19) ◽  
pp. 8182
Author(s):  
Nuhu Dalhat Mu’azu ◽  
Omar Alagha ◽  
Ismail Anil

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.


2020 ◽  
Vol 66 (1) ◽  
pp. 59-70
Author(s):  
Dan Li ◽  
Xihong Liang ◽  
Zhengwei Li ◽  
Yao Jin ◽  
Rongqing Zhou ◽  
...  

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.


1977 ◽  
Vol 8 (3) ◽  
pp. 315-351 ◽  
Author(s):  
Lawrence K. Wang ◽  
Calvin P. C. Poon ◽  
Mu Hao Wang

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