Advanced treatment by anaerobic process followed by aerobic membrane bioreactor for effluent reuse in paper mill industry

2004 ◽  
Vol 50 (3) ◽  
pp. 245-252 ◽  
Author(s):  
N. Stahl ◽  
A. Tenenbaum ◽  
N.I. Galil

The operation of an activated sludge process at a paper mill (AIPM) in Hedera, Israel, was often characterized by disturbances. As part of a research and development project, a study on new biological treatment was initiated. The study included the operation of three pilot units: a. anaerobic treatment by upflow anaerobic sludge blanket (UASB); b. aerobic treatment by two pilot units including activated sludge and membrane bioreactor (MBR), which have been operated in parallel for comparison reasons. The pilot plant working on anaerobic treatment performed COD reduction from 2,365 to 755 mg/L, expressed as average values. Based on the pilot study, a full scale anaerobic treatment system has been erected. During a period of 100 days, after achieving steady state, the MBR system provided steady operation performance, while the activated sludge produced effluent characterized by oscillatory qualities. The following results, based on average values, indicate much lower suspended solids concentrations in the MBR effluent, 2.5 mg/L, as compared to 25 mg/L in the activated sludge. The ability to develop and maintain a concentration of over 11,000 mg/L of mixed liquor volatile suspended solids in the MBR enabled an intensive bioprocess at relatively high cell residence time. This study demonstrates that the anaerobic process, followed by aerobic MBR can provide effluent of high quality which can be considered for economic reuse in the paper mill industry.

2018 ◽  
Vol 78 (9) ◽  
pp. 1966-1979 ◽  
Author(s):  
V. T. Mota ◽  
M. Zaiat

Abstract Two- and single-stage anaerobic treatment systems were assessed for treatment performance and for bioenergy production from sucrose-based wastewater. In the two-stage system, a hydrogen-producing upflow anaerobic sludge blanket reactor (HU reactor) was used in the acidogenic phase. The methanogenic reactor of the two-stage system (MF reactor) and the single-stage reactor (SSF reactor) were structured fixed-bed reactors. The two-stage system showed superior performance, evidenced by lower organic acids, chemical oxygen demand (COD) and suspended solids concentrations in the effluent, and higher biogas methane content and yield. Continuous and stable H2 production was obtained in the acidogenic reactor. At the end of operation, the organic loading rates applied to the two- and single-stage systems were 6.4 and 5.2 gCOD L−1 d−1, respectively. Under these conditions, the effluent soluble COD and volatile suspended solids (VSS) concentrations were 165 and 92 mg L−1 in the two-stage system, and 256 and 244 mg L−1 in the single-stage system, respectively. The energy yield of the two-stage system was 20.69 kJ g−1CODadded, which was 34% higher than the yield of the single-stage system. The sequencing analyses showed that the archaeal distribution changed little between the inoculum and sludge from the MF reactor, in which acetoclastic Methanosaeta was predominant. However, hydrogenotrophic Methanospirillum was found most, followed by Methanosaeta, in the sludge from the SSF reactor.


2003 ◽  
Vol 48 (8) ◽  
pp. 103-110 ◽  
Author(s):  
N.I. Galil ◽  
Ch. Sheindorf ◽  
N. Stahl ◽  
A. Tenenbaum ◽  
Y. Levinsky

The full-scale existing treatment plant in a paper mill in Hedera, Israel, includes equalization, solids separation by either straining or by dissolved air flotation and biological treatment by activated sludge. The operation of the existing biological process is often characterized by disturbances, mainly bad settling, voluminous bioflocs, followed by wash-out of the biosolids. This paper summarizes the results obtained in a study based on a pilot plant including a membrane biological reactor (MBR) compared to the “conventional” activated sludge process in the aerobic treatment of the effluent obtained from an anaerobic reactor. During the pilot operation period (about 90 days after achieving steady state) the MBR system provided steady operation performance, while the activated sludge produced effluent characterized by oscillatory values. The results are based on average values and indicate much lower levels of suspended solids in the MBR effluent, 2.5 mg/L, as compared to 37 mg/L in the activated sludge. As a result, the total organic mater content was also substantially lower in the MBR effluent, 129 vs 204 mg/L as COD, and 7.1 vs 83 mg/L as BOD. The MBR enabled better nitrification. The ability to develop and maintain a concentration of over 11,000 mg/L of mixed liquor volatile suspended solids in the MBR bioreactor enabled an intensive bioprocess at relatively high cell residence time. As a result the biosolids which had to be removed as excess sludge were characterized by relatively low volatile/total suspended solids ratio, around 0.78. This could facilitate and lower the cost of biosolids treatment and handling. The results of this comparative study indicate that in the case of MBR there will be no need for further treatment, while after activated sludge additional filtration will be required. The study leads to the conclusion that MBR will be the best technology for aerobic treatment of the anaerobic effluent of the paper mill.


2010 ◽  
Vol 61 (9) ◽  
pp. 2399-2406 ◽  
Author(s):  
Z. Sawajneh ◽  
A. Al-Omari ◽  
M. Halalsheh

An anaerobic treatment system that consists of an Anaerobic Filter (AF) and an Upflow Anaerobic Sludge Blanket (UASB) in series was built and operated to investigate its performance in treating strong domestic wastewater with high suspended solids fraction under Jordan's ambient temperatures of 25°C for summer and 18°C for winter. The system was operated from September 2003 until early April 2004. The system was operated at a Hydraulic Retention Time (HRT) of 4 hours for the first stage AF and 8 hours for the second stage UASB. Average CODt and CODss removal efficiencies of the AF/UASB were 58% and 81% respectively for the operation period. The results showed that the first stage AF was effective in removing suspended solids. In addition, hydrolysis, acidification and methanogenesis took place in the first stage AF which was advantageous to the second stage UASB. It was concluded that the AF/UASB system is effective in treating strong domestic wastewater with high suspended solids content under Jordan's ambient temperatures.


2007 ◽  
Vol 55 (6) ◽  
pp. 23-29 ◽  
Author(s):  
M. Lerner ◽  
N. Stahl ◽  
N.I. Galil

The study was based on a full scale activated sludge plant (AS) compared to a parallel operated pilot membrane bioreactor (MBR) with flat sheets membranes. Both systems received their influent from an anaerobic bioreactor treating paper mill wastewater. MBR produced an effluent of much better quality than AS in terms of suspended solids, containing 1 mg/L or less in 80% of the monitoring time, while the AS effluent contained 12 mg/L. This could save the necessity of further treatment by filtration in the case of MBR. Other effluent quality parameters, such as organic matter (COD and BOD), phosphorus and ammonia nitrogen, did not indicate substantial differences between AS and MBR. Calcium carbonate scaling and formation of a bacterial layer on the membrane caused severe flux reduction. The membrane blockage because of scaling and biofouling proved to be very serious, therefore, it required proper and more complicated maintenance than the AS system. This study leads to the conclusion that in the case of paper mill wastewater, after anaerobic biotreatment, if there is no need for excellent effluent quality in terms of suspended solids, the replacement of the AS by the MBR would not be strongly justified, mainly because of maintenance cost.


2009 ◽  
Vol 4 (1) ◽  
Author(s):  
E. P. Jordäo ◽  
I. Volschan ◽  
P. Alem Sobrinho

Anaerobic treatment, such as the Upflow Anaerobic Sludge Blanket - UASB - has many advantages: a compact system, with practically no equipment in the anaerobic vessel, low operational costs, very low energy consumption, and low excess sludge produced. However, taking into account its poor effluent quality, and the legal water quality standards, post treatment is a must. Brazil is experiencing the scheme UASB plus aerobic secondary treatment, aiming reduction in investment and mainly in operational costs, with excellent results. Three cases are discussed in this paper: two small plants, Barreto (0,14 m3/s) and Itaipu (0.07 m3/s, 1.6 MGD); and the Rio Preto plant (1.34 m3/s), the first two already operational. All adopt the UASB plus activated sludge process, the last two with denitrification. Several other important plants are in the stage of design or construction in Brazil, with flows as high as 3.35 m3/s, UASB plus activated sludge with nitrogen and phosphorus removal and UASB plus trickling filters. Design criteria for the anaerobic reactor and for the different secondary treatment processes, and available operational data as well, are discussed in the paper. Particular attention is given to special restraints with activated sludge as post treatment, such as the higher sludge age required for nitrification, and the difficulty in denitrifying the anaerobic effluent.


2006 ◽  
Vol 1 (3) ◽  
Author(s):  
A. P. Buzzini ◽  
M. A. Nolasco ◽  
A. M. Springer ◽  
E. C. Pires

The purposes of the experiments described in this paper were to evaluate the performance of an upflow anaerobic sludge blanket (UASB) activated sludge reactor, both bench scale reactors, in the treatment of wastewaters containing organochlorines compounds, which simulate a kraft plant wastewater. Both reactors received a wastewater prepared with diluted black liquor and a mixture of organochlorines: 2 Chlorophenol (2 CP); 2,4 Dichlorophenol (2,4 DCP); 2,6 Dichlorophenol (2,6 DCP); 2,4,6 Trichlorophenol (2,4,6 TCP); and Tetrachlorocatechol (TeCC). The activated sludge reactor also received 4, 5, 6 Trichloroguaiacol (4, 5, 6 TCG). The chemical oxygen demand (COD) and organochlorine concentrations in the effluent indicated that the two systems displayed a similar performance in terms of COD removal, with average efficiencies of 79% for the UASB reactor and of 77% for the activated sludge reactor. The average individual values for organochlorine removal efficiency, the first figure representing the UASB reactor removal, were: 99.9% and 91% for the 2 CP; 97% and 80% for the 2,4 DCP; 94% and 80% for the 2,6 DCP; 99% and 75% for the 2,4,6 TCP; and 93% and 90% for the TeCC. Both systems showed to be capable of treating pulp plant wastewaters containing chlorophenols, with a certain advantage for the anaerobic system from the standpoint of removal efficiencies.


2002 ◽  
Vol 45 (4-5) ◽  
pp. 279-287
Author(s):  
C.M. Polito-Braga ◽  
M. von Sperling ◽  
A.R. Braga ◽  
R.T. Pena

This paper presents a combined wastewater treatment configuration composed by an Upflow Anaerobic Sludge Blanket (UASB) reactor followed by an Activated Sludge (AS) system. A control strategy has been developed for this innovative (especially for domestic sewage) treatment configuration and tested in a real pilot-scale system called STEPAA – Wastewater Treatment System by Anaerobic and Aerobic Processes. The proposed UASB–AS control strategy, including fault detection and recovery, and its successful implementation in real time is presented. This novel control strategy was developed to keep the final effluent suspended solids concentration in the range specified by the State environmental agency, in spite of incoming load disturbances. The control strategy is based on two cascaded PI (Proportional + Integral) controllers, which manipulates the recycling rate into the AS-reactor to control the effluent suspended solids concentration. A 2-dimensional nonlinear mapping (an empirical look-up table), which gives the sludge waste rate as a function of the influent flowrate and AS-reactor biomass concentration, is used to keep the AS-reactor biomass concentration in a range that guarantees a good substrate removal without inconveniences to the AS-settler operation (and consequently to the solids removal). Experimental results are provided to demonstrate the system performance.


1997 ◽  
Vol 35 (8) ◽  
pp. 247-253 ◽  
Author(s):  
Herbert H. P. Fang ◽  
Ivan W. C. Lau ◽  
Denis W. C. Chung

The effects of nine common aromatic pollutants from chemical industry on the bioactivity of anaerobic granules were examined. The granules were obtained from an upflow anaerobic sludge blanket (UASB) reactor treating wastewater containing colloidal starch. The specific methanogenic activities (SMA) of granules were measured at 37°C in serum vials using 3000 mg/l of colloidal starch as substrate, plus individual pollutants at various concentrations. The toxicity was expressed by the IR50 and IC50 values, i.e. the toxicant/biomass ratio and concentration at which levels the granules exhibited only 50% of their original bioactivities. Results showed that in general the granules exhibited mild resistance to toxicity of aromatic pollutants, probably due to the granules' layered microstructure. The toxicities, which were dependent on the nature of chemical functional group, of the aromatic pollutants were in the following descending order: cresols > phenol > hydroxyphenols/phthalate > benzoate. There was only marginal difference between the toxicity of the steric isomers. For the seven phenolic pollutants, the more hydrophobic the functional group the higher the toxicity. The granules' resistance to toxicity suggested the plausibility of anaerobic treatment of wastewater from the chemical industry.


1999 ◽  
Vol 40 (1) ◽  
pp. 77-84 ◽  
Author(s):  
H. H. P. Fang ◽  
D. Wai-Chung Chung

Experiments were conducted in two 2.8 liter UASB (upflow anaerobic sludge blanket) reactors treating proteinaceous wastewaters at 37° and 55°C with 9 hours of hydraulic retention. Results showed that the mesophilic reactor consistently removed 83.5-85.1% of COD (chemical oxygen demand) at loading rates ranging 8-22 g COD l−1 d−1 (corresponding to 3000-8250 mg l−1 of proteinaceous COD in wastewater), whereas the thermophilic reactor removed only 68.5-82.7%. At 32 g COD l−1 d−1 (i.e. 12000 mg COD l−1), the removal efficiencies were lowered to 75.7% in the mesophilic reactor and 65.1% in the thermophilic reactor. At 42 g COD l−1 d−1, severe sludge washout occurred in the mesophilic reactor; at the same loading rate, the thermophilic reactor removed only 53.8% of COD even though sludge washout was under control. The degradation rate in the both reactors was limited by the initial hydrolysis of proteins. However, batch tests showed that thermophilic sludge had slightly higher methanogenic activities than mesophilic sludge in treating proteins and intermediate acids, except propionate. The sludge yields in mesophilic and thermophilic reactors were 0.066 and 0.099 g VSS g COD−1, respectively. Observations by scanning electron microscopy indicated that both types of sludge granules were of irregular shape. There was little noticeable difference between the two granules; both had neither a layered microstructure nor a predominant bacterial species.


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