Full-scale on-line assessment of toxic wastewaters causing change in biodegradation model structure and parameters

1996 ◽  
Vol 33 (2) ◽  
pp. 163-175 ◽  
Author(s):  
Peter A. Vanrolleghem ◽  
Zaide Kong ◽  
Filip Coen

Detecting wastewater toxicity in due time is essential for protection of a sewage works and the receiving waters. A respirometric method is presented that performs short batch experiments, so-called In-Sensor-Experiments for toxicity detection. Two types of wastewater samples can be added to the reactor in the device: either the potentially toxic wastewater entering the plant, or, a defined mixture of acetate and ammonia. From the latter experiments models are identified that describe the heterotrophic and autotrophic activity of the sludge. Since these ‘calibration’ experiments are alternated with experiments in which wastewater is injected, the effect of the wastewater on the sludge can be quantified unequivocally. Full-scale toxicity detection (and the corresponding effluent quality) results are reported for a plant treating a mixture of hospital and municipal wastewaters. The respirometer was installed at the influent line of the plant. It was evaluated during a 6-month period for its on-line toxicity detection capacity. Both deliberate and accidental intoxications were recorded and compared with off-line toxicity measurements. Inhibitory wastewaters affected the nitrification activity of the sludge. This was confirmed by the concomitant increase in NH4+ discharge of the treatment plant. To evaluate the efficiency of control actions, the deliberate addition of toxicant was interrupted at the time a toxicity alarm was triggered by the respirometer. It was observed that plant performance then remained unaffected for all monitored criteria.

2006 ◽  
Vol 54 (10) ◽  
pp. 201-208 ◽  
Author(s):  
B.-M. Wilén ◽  
D. Lumley ◽  
A. Mattsson ◽  
T. Mino

The effect of rain events on effluent quality dynamics was studied at a full scale activated sludge wastewater treatment plant which has a process solution incorporating pre-denitrification in activated sludge with post-nitrification in trickling filters. The incoming wastewater flow varies significantly due to a combined sewer system. Changed flow conditions have an impact on the whole treatment process since the recirculation to the trickling filters is set by the hydraulic limitations of the secondary settlers. Apart from causing different hydraulic conditions in the plant, increased flow due to rain or snow-melting, changes the properties of the incoming wastewater which affects process performance and effluent quality, especially the particle removal efficiency. A comprehensive set of on-line and laboratory data were collected and analysed to assess the impact of rain events on the plant performance.


1991 ◽  
Vol 24 (5) ◽  
pp. 189-196 ◽  
Author(s):  
S. B. Guo ◽  
R. Z. Chen ◽  
G. Li ◽  
H. Y. Shoichi

In 1987 Guangzhou Liede Nightsoil Treatment Plant started commissioning. The purpose of the plant is to dispose of 400 tons of nightsoi1 from city public toilets per day. In the first year of the commissioning a biological process was basically used according to the original design made by a Danish company. Practically it has been proved that the design is effective. The process can reduce BOD from 3800 mg/l to about 133 mg/l, or by approximately 96.5 percent. The performance of the sludge digester system is satisfactory. Because the primary investigation on characteristics of the nightsoil was insufficient there were some problems raised during the commissioning. So in the first year the effluent failed to achieve the desired quality. After the analysis of the plant performance some necessary reforms have been carried out. Now the effluent quality can stably meet the national discharge limits and the treatment cost decreases.


1996 ◽  
Vol 33 (1) ◽  
pp. 81-87
Author(s):  
L. Van Vooren ◽  
P. Willems ◽  
J. P. Ottoy ◽  
G. C. Vansteenkiste ◽  
W. Verstraete

The use of an automatic on-line titration unit for monitoring the effluent quality of wastewater plants is presented. Buffer capacity curves of different effluent types were studied and validation results are presented for both domestic and industrial full-scale wastewater treatment plants. Ammonium and ortho-phosphate monitoring of the effluent were established by using a simple titration device, connected to a data-interpretation unit. The use of this sensor as the activator of an effluent quality proportional sampler is discussed.


2018 ◽  
Vol 13 (3) ◽  
pp. 566-582 ◽  
Author(s):  
Nadja Hvala ◽  
Darko Vrečko ◽  
Cirila Bordon

Abstract This paper presents the design of a plant-wide CNP (carbon-nitrogen-phosphorus) simulation model of a full-scale wastewater treatment plant, which will be upgraded for tertiary treatment to achieve compliance with effluent total nitrogen (TN) and total phosphorus (TP) limit values. The plant-wide model of the existing plant was first designed and extensively validated under long-term dynamic operation. The most crucial step was a precise characterization of input wastewater that was performed by extending the plant performance indicators both to a water line and sludge line and systematically estimating identifiable wastewater characterization parameters from plant-wide performance indicators, i.e. effluent concentrations, biogas and sludge production, and sludge composition. The thus constructed simulation model with standard activated sludge model (ASM2d) and anaerobic digestion model (MantisAD) overpredicted ortho-P and ammonia-N on the sludge line, indicating a need to integrate state-of-the-art physico-chemical minerals precipitation models to simulate plant-wide interactions more precisely. The upgraded plant with multimode anaerobic/anoxic/oxic configuration shows limited denitrification potential. Therefore, additional reject water treatment was evaluated to improve effluent TN and TP performance.


2001 ◽  
Vol 43 (3) ◽  
pp. 347-354 ◽  
Author(s):  
T. G. Flapper ◽  
N. J. Ashbolt ◽  
A. T. Lee ◽  
M. O'Neill

This paper describes the path taken from client objectives through laboratory studies and detailed design to full-scale SBR operation and current research. Conventional municipal design principles have often been used to develop treatment processes for industrial wastewaters. The use of scientific trials to test design criteria offers the client a “tailor made” design fit for their particular wastewater character. In this project, a waste management company wished to upgrade their physical-chemical treatment plant to incorporate a biological reactor for treating a range of industrial wastewaters. Laboratory-scale trials were undertaken to determine appropriate design criteria for a full-scale biological process. These laboratory studies indicated that conventional design criteria were not appropriate and that a SBR configuration was optimal compared with an IDAR configuration. It was also found that a novel fungal:bacterial mixed liquor consortium developed, resulting in good effluent quality and settling properties. The treatment plant was able to be constructed and operational within a tight timeframe and budget, allowing the client to take advantage of a commercial opportunity. The plant has been operating since 1997 and meets its discharge conditions. By combining scientific studies with engineering principles, the end-user obtained a complete treatment plant to meet their specific needs. A further benefit of the laboratory trials is current research into the development of a fungal:bacterial SBR to treat industrial wastewaters. This offers ongoing knowledge to the operational full-scale SBR.


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.


1994 ◽  
Vol 30 (4) ◽  
pp. 243-253 ◽  
Author(s):  
P. Vanrolleghem ◽  
M. Van Daele

The interaction between activated sludge and a wastewater is subject to important cbanges. This is reflected not only in changing biokinetic parameters but also in changing model structures. The need to select the ‘ right’ model structure in a reliable way on the basis of respirographic data provided by on-line sensors imposes serious real-time constraints on the methods used. First of all, fast structure characterization methods are presented allowing us to track the model structure on-line. Since these so-called a priori methods are less computing intensive, they can be at the basis of optimal experimental design calculations that can be performed on-line. This allows us to maintain the quality of the overall model identification under the changing process conditions of a wastewater treatment plant. Two applications of Optimal Experimental Design are given.


1994 ◽  
Vol 30 (3) ◽  
pp. 119-128
Author(s):  
Elemér Dobolyi ◽  
Imre Takács

An existing rendering plant wastewater treatment facility has to be upgraded to meet the newly set British and more stringent EC effluent standards. After detailed analysis it turned out, that the existing treatment plant cannot be upgraded, a new plant has to be built. The rendering plant processes slaughterhouse wastes. The wastewater contains easily biodegradable organic substances, mainly organic acids, organic bonded nitrogen and ammonia. According to the new effluent standards the main task, besides the organic removal was the complete removal of nitrogen. The aim of this study was to find out the best available technology and the basic wastewater design data. For this purpose, on site pilot scale experiments were carried out. In several test runs the influent BOD and T K N have varied of between 1400-5500 and 460-1120 mg/l, respectively. Based on the experimental results, single-sludge nitrification-denitrification technology was selected for the full scale treatment plant. The plant was extended by chemical phosphate removal applying the post-precipitation method. In addition to the experimental schedule, a mathematical model of the plant was developed for two purposes.– to verify the applicability of the general activated sludge model under high concentration influent conditions, and– to generalize experimental results and provide a tool to predict plant performance under full scale conditions. On the basis of successful pilot plant experiments and model calibration, full scale plant design parameters were determined and presented. The full scale plant is under construction.


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