Effluent quality variation from multicomponent substrates in the activated sludge process

1980 ◽  
Vol 14 (5) ◽  
pp. 471-476 ◽  
Author(s):  
S SIBER ◽  
W ECKENFELDERJR
1998 ◽  
Vol 38 (4-5) ◽  
pp. 9-17 ◽  
Author(s):  
F. Germirli Babuna ◽  
D. Orhon ◽  
E. Ubay Çokgör ◽  
G. Insel ◽  
B. Yaprakli

A comprehensive evaluation of four different textile wastewaters was carried out to set the experimental basis for the modelling of activated sludge process. Experiments involved beside conventional characterization, detailed COD fractionation and assessment of major kinetic and stoichiometric coefficients by means of respirometric measurements. A multi-component model based on the endogenous decay concept was used for the kinetic interpretation and design of activated sludge. The fate and variation of major process components affecting effluent quality with the sludge age were evaluated by means of model simulations.


2002 ◽  
Vol 46 (9) ◽  
pp. 229-236 ◽  
Author(s):  
M.R. Alavi Moghaddam ◽  
H. Satoh ◽  
T. Mino

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.


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.


1997 ◽  
Vol 36 (11) ◽  
pp. 163-170 ◽  
Author(s):  
Yoshio Sakai ◽  
Tetsuro Fukase ◽  
Hidenari Yasui ◽  
Masahide Shibata

An activated sludge process which produces no excess sludge was developed. The process is very simple as a small amount of return sludge is ozonated and then returned to the aeration tank. The ozonation enhances biodegradability of activated sludge, which is biologically oxidized in the aeration tank. A full-scale plant for treating 450m3/d of municipal wastewater was constructed and has been operated successfully for 9 months. The amount of excess sludge eliminated is directly proportional to the amount of ozone dosed to the sludge. At the ozone dosing rate of 0.034 kg/kg-SS, complete elimination of excess sludge has been achieved when 4 times more amount of sludge is ozonated than that of the excess sludge expected in the treatment without ozonation. After 5 months of operation without any withdrawal of excess sludge, small amount of inorganic substances like sand and silt accumulated in the sludge. On the other hand, inert organic substances does not seem to accumulate. As for effluent quality, BOD and nitrogen were kept good. Although effluent SS was 2–15 mg/l higher compared to a control without ozonation, it has been well below the discharge limit.


1998 ◽  
Vol 38 (4-5) ◽  
pp. 355-362 ◽  
Author(s):  
D. Orhon ◽  
S. Sözen ◽  
E. Ubay Çokgör ◽  
E. Ates Genceli

The effect of chemical settling of tannery wastewaters on the kinetic behaviour and performance of activated sludge process is investigated on the basis of experimentally supported model evaluations. Experiments involved besidese conventional characterization, detailed COD fractionation and assessment of major kinetic and stoichiometric coefficients by means of respirometric measurements. A multi-component model based on the endogenous decay concept was used for the kinetic interpretation and design of activated sludge. Results indicated that chemical settling as a pretreatment step induced a totally different kinetic pattern, significantly improving the biological treatability of tannery wastewaters. Design implications were evaluated in terms of major parameters of practical importance, such as effluent quality, activated sludge composition, aeration volume, oxygen demand and sludge generation.


1998 ◽  
Vol 38 (8-9) ◽  
pp. 137-144 ◽  
Author(s):  
Maxine Mayhew ◽  
Tom Stephenson

The emphasis for operation of the activated sludge process has switched from the volume of wastewater turnover and effluent quality to minimisation of biomass produced. Attempts including extended aeration, promotion of bacterial predation by higher organisms and increasing process temperature have been successful in lowering yield. These all involve increased operating costs and capital works, whereas the process of chemical uncoupling may be cheaper. After initial chemical screening 2,4 dinitrophenol (2,4 DNP) was continuously dosed in an activated sludge simulation (31 working volume, 5.55h HRT). Effect on process efficiency was monitored by measuring BOD removal and biomass production by MLSS. After 7 weeks of chemical treatment the mean yield coefficient of the treated simulation (Y=0.30) was significantly lower than that of the control (Y=0.42). BOD removal from treated and control samples was comparable and not significantly different.


2000 ◽  
Vol 41 (1) ◽  
pp. 49-52 ◽  
Author(s):  
L. Akca ◽  
A. Samsunlu

In accordance with the development of tourism, sea pollution has become the major problem of the coastal zones. In order to realize sustainable touristic activities in Turkey, it is very important to treat wastewater and preserve the environmental quality. It is roughly estimated that there are around 2000 small treatment plants in Turkey. However, it is necessary to construct 10,000 more wastewater treatment plants to solve the wastewater problems in small settlements. In this study, performances of small treatment systems were investigated. Two types of the treatment plants were of concern. The first one is a continuous system based on fixed bed activated sludge process, whereas the second system is based on batch activated sludge process. 96 treatment plants have been investigated in this study. The wastewater characteristic is determined as strong domestic wastewater. It has been observed that the effluent quality of the batch activated sludge and aerated biofilter systems meet the discharge requirements of Water Pollution Control Regulation in Turkey. Furthermore, they would be easily adapted to meet the stringent standards that are proposed for sensitive zones.


Sign in / Sign up

Export Citation Format

Share Document