A proposed sustainable BNR plant with the emphasis on recovery of COD and phosphate

2003 ◽  
Vol 48 (1) ◽  
pp. 77-85 ◽  
Author(s):  
X.-D. Hao ◽  
M.C.M. van Loosdrecht

Water problems have to be solved in an integrated way, and sustainability has become a major issue. For this reason, developing more sustainable wastewater treatment processes is needed. New discoveries and good understanding on microbial conversions of nitrogen and phosphorus make more sustainable processes possible. New options for decentralized sustainable sanitation are generally compared to conventional sewage systems, we think that for a proper comparison also innovative centralized treatment schemes should be evaluated. In this article, a more sustainable WWTP is proposed for municipal wastewater treatment, mainly based on the principles of denitrifying dephosphatation and anaerobic ammonium oxidation (ANAMMOX). The proposed system consists of a first stage of the A/B process in which maximal sludge production is achieved. In this way, COD is regained as sludge for methanation. The following BCFS® and CANON processes can remove N and P with minimal or no COD need. As a potential fertiliser, struvite can easily be removed from the sludge water by adding magnesium compounds. A case study is done on the basis of the mass balance over the proposed plant. The effluent from the system has a good quality to be recycled. This could also make a contribution to meeting the world's water needs and lessening the impact on the world's water environment. Since all the separate units are already applied or tested on pilot-scale, no problems for technical implementation are foreseen.

1990 ◽  
Vol 22 (7-8) ◽  
pp. 225-232
Author(s):  
G. Petersen

The upgrading of an existing mechanical wastewater treatment plant to meet the new standards for effluent quality in the Municipality of Fredericia, Denmark, are presented. The Municipality has a lot of very big organic and inorganic industries, which leaves several different possibilities for treatment strategies. In 1987 pilot-scale tests were carried out to study the effects of various combinations of wastewater types on the treatment efficiency, and the tests resulted in two main solutions for the wastewater treatment system. The pilot-scale tests were run in a two - stage biology plant. The first stage was either a BIOSORPTION unit or a PRE-DENITRIFICATION unit. The second stage was a biological nitrogen and phosphorus removal unit (a BIO-DENIPHO unit).


2011 ◽  
Vol 64 (8) ◽  
pp. 1730-1735 ◽  
Author(s):  
G. Guglielmi ◽  
G. Andreottola

A large pilot-scale membrane bioreactor (MBR) with a conventional denitrification/nitrification scheme for municipal wastewater treatment has been run for one year under two different aeration strategies in the oxidation/nitrification compartment. During the first five months air supply was provided according to the dissolved-oxygen set-point and the system run as a conventional pre-denitrification MBR; then, an intermittent aeration strategy based on effluent ammonia nitrogen was adopted in the aerobic compartment in order to assess the impact on process performances in terms of N and P removal, energy consumption and sludge reduction. The experimental inferences show a significant improvement of the effluent quality as COD and total nitrogen, both due to a better utilization of the denitrification potential which is a function of the available electron donor (biodegradable COD) and electron acceptor (nitric nitrogen); particularly, nitrogen removal increased from 67% to 75%. At the same time, a more effective biological phosphorus removal was observed as a consequence of better selection of denitrifying phosphorus accumulating organisms (dPAO). The longer duration of anoxic phases also reflected in a lower excess sludge production (12% decrease) compared with the standard pre-denitrification operation and in a decrease of energy consumption for oxygen supply (about 50%).


2010 ◽  
Vol 2010 ◽  
pp. 1-10 ◽  
Author(s):  
Yong Qiu ◽  
Han-chang Shi ◽  
Miao He

Surface water environment in China was degraded rapidly in the last two decades, resulting in increasingly tighten criteria issued for municipal wastewater treatment plants (WWTPs). This paper reviewed the recent advances of process design and operational optimization for nutrients removal. Three major processes, as anaerobic-anoxic-oxic (AAO) process, oxidation ditch (OD), and sequencing batch reactor (SBR) occupied 65% of WWTPs amounts and 54% of treatment volumes of China in 2006. However conservative process designs and operational faults often impaired the process performances and energy efficiency. Therefore, typical processes were modified, combined, and innovated to meet the requirements of the diverse influent characteristics and lower energy consumptions. Furthermore, operational optimization techniques by modeling, simulation, and real-time control were also developed and applied in China to improve the process operation. Although great efforts had been contributed to improve the WWTPs performances in China, attentions should be continuously paid to the introduction, instruction, and implementation of advanced techniques. At last, the technical demands and appropriated techniques of WWTPs in China were briefly discussed.


2003 ◽  
Vol 48 (5) ◽  
pp. 257-266 ◽  
Author(s):  
K. Boonsong ◽  
S. Piyatiratitivorakul ◽  
P. Patanaponpaiboon

The study evaluated the possibility of using mangrove plantation to treat municipal wastewater. Two types of pilot scale (100 × 150 m2) free water surface constructed wetland were set up. One system was a natural Avicennia marina dominated forest system. The other system was a newly planted system in which seedlings of Rhizophora spp., A. marina, Bruguiera cylindrica and Ceriops tagal were planted in 4 strips. Municipal wastewater was retained within the systems for 7 and 3 days, respectively. The results indicated that the average removal percentage of TSS, BOD, NO3-N, NH4-N, TN, PO4-P and TP in the newly planted system were 27.6-77.1, 43.9-53.9, 37.6-47.5, 81.1-85.9, 44.8-54.4, 24.7-76.8 and 22.6-65.3, respectively. Whereas the removal percentage of those parameters in the natural forest system were 17.1-65.9, 49.5-51.1, 44.0-60.9, 51.1-83.5, 43.4-50.4, 28.7-58.9 and 28.3-48.0, respectively. Generally, the removal percentages within the newly planted system and the natural forest system were not significantly different. However, when the removal percentages were compared with detention time, TSS, PO4-P and TP percentages removed were significantly higher in the 7-day detention time treatment. Even though the removal percentages were highly varied and temporally dependent, the overall results showed that mangrove plantation could be used as constructed wetland for municipal wastewater treatment in a similar way to the natural mangrove system.


2000 ◽  
Vol 41 (7) ◽  
pp. 31-37 ◽  
Author(s):  
E. Carraro ◽  
E. Fea ◽  
S. Salva ◽  
G. Gilli

The aim of this study was to assess the impact of a municipal wastewater treatment plant (MWTP) on the occurrence of Cryptosporidium oocysts and Giardia cysts in the receiving water. All MWTP effluent samples were Giardia and Cryptosporidium contaminated, although low mean values were found for both parasites (0.21±0.06 oocysts/L; 1.39±0.51 cysts/L). Otherwise, in the raw sewage a greater concentration was detected (4.5±0.3 oocysts/L; 53.6±6.8 cysts/L). The major occurrence of Giardia over Cryptosporidium, both in the influent and in the effluent of the MWTP, is probably related to the human sewage contribution to the wastewater. Data on protozoa contamination of the receiving water body demonstrated similar concentrations in the samples collected before (0.21±0.07 oocysts/L; 1.31±0.38 cysts/L) and after (0.17±0.09 oocysts/L and 1.01±1.05 cysts/L) the plant effluent discharge. The results of this study suggest that the MWTP has no impact related to Giardia and Cryptosporidium river water contamination, and underline the need for investigation into the effectiveness of these protozoa removal by less technologically advanced MWTPs which are the most widespread and could probably show a lower ability to reduce protozoa.


Author(s):  
Klaus Doelle ◽  
Qian Wang

The study tested a designed and built pilot scale packed bio-tower system under continuous operation using pre-clarified municipal wastewater. Performance was evaluated by measuring the removal of chemical oxygen demand and nitrogen ammonia. The pilot scale packed bio-tower system had a diameter of 1209 mm (4 ft.) and a height of 3,962 mm (13 ft.) and contained Bentwood CF-1900 bacteria growth media with a surface area of 6,028.80 ft² (560.09 m²). The municipal residential sewage was fed into a 1,481 l (375 gal.) recirculation reservoir at a temperature of 15°C (59.0°F) and a flow rate between 7,571 l/d (2000 gal/d) and 90,850 l/d (24,000 gal/d) and recirculated through the bio-tower with a fixed recirculation rate of 75.7 l/min (20 gal/min). The influent COD value reduction achieved is between 63.4% and 84.8%, whereas the COD influent value varied between 87 mg/l and 140 mg/l. The influent NH3-N reduction achieved was between 99.8% and 91.8% whereas the influent NH3-N value was between 28.8 mg/l and 18.6 mg/l  at a flow rate between 7571 l/d (2000 gal/d) and 90,850 l/d (24,000 gal/d).


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