PACTTM process for treatment of kraft mill effluent

1997 ◽  
Vol 35 (2-3) ◽  
pp. 283-290 ◽  
Author(s):  
R. M. Narbaitz ◽  
R. L. Droste ◽  
L. Fernandes ◽  
K. J. Kennedy ◽  
D. Ball

The PACTTM process (powdered activated carbon addition to the activated sludge process) was evaluated for the treatment of Kraft pulp mill wastewater in a series of bench scale experiments. Possibly due to the relatively low strength wastewater, the PACTTM process with carbon doses between 0.5 and 1.0 g/L of influent only performed marginally better than the conventional activated sludge process. Chemical oxygen demand and toxicity, evaluated with the Microtox® assay, were among the parameters monitored. For the operating conditions tested the solids retention time had no impact on performance. The main improvement was increased in adsorbable organic halides (AOX) removal, the magnitude of the improvement was dependent on the wastewater batch and the carbon dose. However conventional activated sludge treatment will meet Ontario's year 2000 AOX regulations. An empirical model from the literature described the data fairly well.

2015 ◽  
Vol 71 (8) ◽  
pp. 1241-1248 ◽  
Author(s):  
Babak Rezania ◽  
Donald S. Mavinic ◽  
Harlan G. Kelly

An innovative granular sludge deammonification system was incorporated into a conventional-activated sludge process. The process incorporated an internal baffle in the bioreactor for continuous separation of granular biomass from flocculent biomass, which allowed for controlling the solids retention time of flocculent sludge. The process was evaluated for ammonium removal from municipal digested sludge dewatering centrate under various operating conditions lasting over 450 days. The process successfully removed, on average, 90% of the ammonium from centrate at various ammonium loading reaching 1.4 kg/m3d at 20 hours hydraulic retention time. Controlling the retention time of the flocculent biomass and maintaining low nitrite concentration were both found to be effective for nitrite oxidizing bacteria management, resulting in a low nitrate concentration (below 50 mg/L) over a wide range of flocculent biomass concentration in the bioreactor.


Author(s):  
Watsa Khongnakorn ◽  
Christelle Wisniewski

In wastewater treatment, the membrane bioreactor (MBR) holds the potential to become one of the new generation processes, ensuring effluent quality and disinfection of sufficiently high levels to allow water reuse and recycle. Furthermore, the possibility to operate with high biomass concentrations (2 to 5 times higher than in conventional activated sludge process, CAS) allows to impose high solid retention times(SRT) that can be beneficial to a sludge production reduction and so to a reduction of disposal costs. These non-conventional operating conditions (high SRT) can also induce different sludge characteristics and dewatering aptitude, which are essential parameters for the optimization of the sludge post-treatment, like mechanical dewatering. The objective of this work was to study the performances of a complete sludge retention membrane bioreactor, in terms of organic removal efficiency, sludge production and sludge dewaterability. The adaptability of Activated Sludge Model 3 (ASM3) to provide good prediction results of high SRT-MBR was studied. Typical parameters adopted to describe sludge dewaterability were quantified and compared with the conventional activated sludge process (CAS).


1992 ◽  
Vol 26 (9-11) ◽  
pp. 2195-2198 ◽  
Author(s):  
S. A. McClintock ◽  
V. M. Pattarkine ◽  
C. W. Randall

Two pilot-scale activated sludge reactors, one VIP (named after Virginia Initiative Plant) biological nutrient removal (BNR) process and one conventional, fully aerobic process, were operated over a range of solids retention times (SRT's) and under the same conditions so that growth yields and specific decay rates could be evaluated and compared. True growth yields (Y's) for the BNR and the conventional processes were equal and were 0.41 gVSS/gCOD. The specific decay rate, b, for the BNR process, 0.063 d, was lower than in the fully aerobic process, 0.110 d-1, indicating that decay occurs at a much lower rate in the anoxic and anaerobic zones of the BNR process.


1994 ◽  
Vol 30 (6) ◽  
pp. 31-40 ◽  
Author(s):  
Hiroyshi Emori ◽  
Hiroki Nakamura ◽  
Tatsuo Sumino ◽  
Tadashi Takeshima ◽  
Katsuzo Motegi ◽  
...  

For the sewage treatment plants near rivers and closed water bodies in urbanized areas in Japan and European countries, there is a growing demand for introduction of advanced treatment processes for nitrogen and phosphorus from the viewpoints of water quality conservation and environmental protection. In order to remove nitrogen by the conventional biological treatment techniques, it is necessary to make a substantial expansion of the facility as compared with the conventional activated sludge process. In such urbanized districts, it is difficult to secure a site and much capital is required to expand the existing treatment plant. To solve these problems, a compact single sludge pre-denitrification process using immobilized nitrifiers was developed. Dosing the pellets, which are suitable for nitrifiers growth and physically durable, into the nitrification tank of single sludge pre-denitrification process made it possible to perform simultaneous removal of BOD and nitrogen in a retention time equal to that in the conventional activated sludge process even at the low water temperature of about 10 °C. The 3,000 m3/d full-scale conventional activated sludge plant was retrofitted and has been successfully operated.


1992 ◽  
Vol 26 (5-6) ◽  
pp. 1355-1363 ◽  
Author(s):  
C-W. Kim ◽  
H. Spanjers ◽  
A. Klapwijk

An on-line respiration meter is presented to monitor three types of respiration rates of activated sludge and to calculate effluent and influent short term biochemical oxygen demand (BODst) in the continuous activated sludge process. This work is to verify if the calculated BODst is reliable and the assumptions made in the course of developing the proposed procedure were acceptable. A mathematical model and a dynamic simulation program are written for an activated sludge model plant along with the respiration meter based on mass balances of BODst and DO. The simulation results show that the three types of respiration rate reach steady state within 15 minutes under reasonable operating conditions. As long as the respiration rate reaches steady state the proposed procedure calculates the respiration rate that is equal to the simulated. Under constant and dynamic BODst loading, the proposed procedure is capable of calculating the effluent and influent BODst with reasonable accuracy.


2010 ◽  
Vol 61 (1) ◽  
pp. 199-205 ◽  
Author(s):  
T. R. Chaparro ◽  
C. M. Botta ◽  
E. C. Pires

Effluents originated in cellulose pulp manufacturing processes are usually toxic and recalcitrant, specially the bleaching effluents, which exhibit high contents of aromatic compounds (e.g. residual lignin derivates). Although biological processes are normally used, their efficiency for the removal of toxic lignin derivates is low. The toxicity and recalcitrance of a bleached Kraft pulp mill were assessed through bioassays and ultraviolet absorption measurements, i.e. acid soluble lignin (ASL), UV280, and specific ultraviolet absorption (SUVA), before and after treatment by an integrated system comprised of an anaerobic packed-bed bioreactor and oxidation step with ozone. Furthermore, adsorbable organic halides (AOX) were measured. The results demonstrated not only that the toxic recalcitrant compounds can be removed successfully using integrated system, but also the ultraviolet absorption measurements can be an interesting control-parameter in a wastewater treatment.


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.


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