Disinfection in a pilot-scale “advanced” pond system (APS) for domestic sewage treatment in New Zealand

2003 ◽  
Vol 48 (2) ◽  
pp. 81-87 ◽  
Author(s):  
R.J. Davies-Colley ◽  
R.J. Craggs ◽  
J.W. Nagels

“Advanced” pond systems (APS) have the potential for improving treatment, including disinfection, over conventional WSPs. Disinfection in a pilot scale APS at Ngatea, New Zealand was studied. This system comprises a high-rate algal pond (HRP) that optimises growth of settleable colonial green algae, followed by an algal settling pond (ASP) that removes much of the nutrients and solids as non-noxious algal sludge, and then a maturation pond (MP) for effluent polishing. Monitoring of this pilot-scale system over 2 years showed excellent overall removal of E. coli (average of 2000-fold reduction), with approximately 1 log removal in each of the three stages. Experiments in the pilot scale HRP suggest that most E. coli removal in this stage is inactivation by sunlight exposure, but with an important contribution from continuous dark processes. Preliminary experiments on the pilot scale algal settling pond (APS) suggest the combined effect of sedimentation of bacteria and sunlight disinfection of the (clarified) supernatant water.

2006 ◽  
Vol 6 (6) ◽  
pp. 43-50 ◽  
Author(s):  
Q. Zhou ◽  
S.L. He ◽  
X.J. He ◽  
X.F. Huang ◽  
B. Picot ◽  
...  

This study focused on the evaluation of performance and mechanisms of a high-rate algal pond system (HRAP System) in nitrogen and phosphorus removal for rural domestic sewage treatment. A pilot scale HRAP System was located at Yangzhu Village, Jiangsu Province, east China, with treatment processes including a septic tank, two stages of HRAPs and an aquatic pond. Results showed that the HRAP System had a good performance in nutrient removal, especially in NH+4-N removal. Total removal efficiencies of COD, TN, NH+4-N and TP were 80, 51.8, 90.2 and 52.1%, respectively. About 61.6% of NH+4-N in the 1st-stage HRAP and 70.9% in the 2nd-stage HRAP were transformed into NO−3-N and NO2−-N through nitrification, and the nitrogen losses via ammonia volatilization was only 2.7% (for 1st-stage HRAP) and 8.8% (for 2nd-stage HRAP). The other 35.7% and 20.3% of NH+4-N removal were achieved by algae assimilation respectively. About 98.0% (for 1st-stage HRAP) and 84.8% (for 2nd-stage HRAP) removal of TN were attributed to algae sedimentation, while those through ammonia volatilization were only 2.0% (for 1st-stage HRAP) and 15.4% (for 2nd-stage HRAP), respectively. Therefore, the main mechanisms of NH+4-N removal in HRAP were nitrification and algae assimilation, and TN was mainly removed by algae sedimentation. About 50.7% (for 1st-stage HRAP) and 53.1% (for 2nd-stage HRAP) of phosphorus in the deposit were organic phosphates respectively, only 20.7% and 27.7% were calcium-bound and magnesium-bound phosphates. The removal mechanism of TP in HRAP could be mainly attributed to algae assimilation in forms of organic phosphate, and chemical precipitation in forms of calcium-bound and magnesium-bound.


2007 ◽  
Vol 51 (1) ◽  
pp. 237-247 ◽  
Author(s):  
Arnaldo Sarti ◽  
Marcelo Loureiro Garcia ◽  
Marcelo Zaiat ◽  
Eugenio Foresti

2001 ◽  
Vol 43 (12) ◽  
pp. 191-193 ◽  
Author(s):  
M. Kaneko ◽  
T. Nambu ◽  
M. Tokoro

“Johkasou” is a small sewage treatment apparatus commonly used in Japan which can effectively treat domestic wastewater in places where a public sewage system is difficult to supply. The behaviour of enterohaemorrhagic E. coli 0157 and Salmonella enteritidis in a “Johkasou” was studied. Their reduction rates depended significantly on the water temperature in the “Johkasou” with minimal decrease in numbers at 10°C within 48 h. The reduction rates increased at 20°C and 30°C where 4 log reduction could be expected. The reduction rates were influenced by the BOD of the solutions that contained the pathogens with the lower the BOD the higher the reduction rate. The reduction rates were about the same between both pathogens. The result showed that it was necessary to disinfect the effluent as some pathogens can pass through the apparatus when some users of the apparatus excrete pathogens.


2015 ◽  
Vol 39 (2) ◽  
pp. 341-352 ◽  
Author(s):  
Flávia Talarico Saia ◽  
Theo S. O. Souza ◽  
Rubens Tadeu Delgado Duarte ◽  
Eloisa Pozzi ◽  
Débora Fonseca ◽  
...  

2014 ◽  
Vol 69 (7) ◽  
pp. 1410-1418 ◽  
Author(s):  
Weijie Guo ◽  
Zhu Li ◽  
Shuiping Cheng ◽  
Wei Liang ◽  
Feng He ◽  
...  

To examine the performance of a constructed wetland system on stormwater runoff and domestic sewage (SRS) treatment in central east China, two parallel pilot-scale integrated constructed wetland (ICW) systems were operated for one year. Each ICW consisted of a down-flow bed, an up-flow bed and a horizontal subsurface flow bed. The average removal rates of chemical oxygen demand (CODCr), total suspended solids (TSS), ammonia (NH4+-N), total nitrogen (TN) and total phosphorus (TP) were 63.6, 91.9, 38.7, 43.0 and 70.0%, respectively, and the corresponding amounts of pollutant retention were approximately 368.3, 284.9, 23.2, 44.6 and 5.9 g m−2 yr−1, respectively. High hydraulic loading rate (HLR) of 200 mm/d and low water temperatures (<15 °C) resulted in significant decrease in removals for TP and NH4+-N, but had no significant effects on removals of COD and TSS. These results indicated that the operation of this ICW at higher HLR (200 mm/d) might be effective and feasible for TSS and COD removal, but for acceptable removal efficiencies of nitrogen and phosphorus it should be operated at lower HLR (100 mm/d). This kind of ICW could be employed as an effective technique for SRS treatment.


2005 ◽  
Vol 51 (12) ◽  
pp. 107-110 ◽  
Author(s):  
R.J. Davies-Colley ◽  
R.J. Craggs ◽  
J. Park ◽  
J.P.S. Sukias ◽  
J.W. Nagels ◽  
...  

Advanced pond systems (APS), incorporating high-rate ponds, algal settling ponds, and maturation ponds, typically achieve better and more consistent disinfection as indicated by Escherichia coli than conventional waste stabilisation ponds. To see whether this superior disinfection extends also to enteric viruses, we studied the removal of somatic phages (‘model’ viruses) in a pilot-scale APS treating sewage. Measurements through the three aerobic stages of the APS showed fairly good removal of somatic phage in the summer months (2.2 log reduction), but much less effective removal in winter (0.45 log reduction), whereas E. coli was removed efficiently (>4 logs) in both seasons. A very steep depth-gradient of sunlight inactivation of somatic phage in APS pond waters (confined in silica test tubes) is consistent with inactivation mainly by solar UVB wavelengths. Data for F-RNA phage suggests involvement of longer UV wavelengths. These findings imply that efficiency of virus removal in APS will vary seasonally with variation in solar UV radiation.


1990 ◽  
Vol 22 (1-2) ◽  
pp. 305-316 ◽  
Author(s):  
G. R. Dillon ◽  
V. K. Thomas

The BIOCARBONE process is a recently developed method for wastewater treatment. High concentrations of active biomass attach to an expanded shale medium in an aerated, packed-bed filter. High-rate biological treatment and in-situ removal of suspended solids are claimed as advantages of the process. The pilot-scale evaluation aimed to assess the performance of the process and its economic feasibility for use in the UK. Carbonaceous oxidation of settled sewage and tertiary nitrification of secondary effluent were investigated in two pilot-scale reactors. Carbonaceous oxidation produced a good-quality effluent at volumetric loading rates up to 4.1 kg BOD5/m3.d (9.2 kg COD/m3,d). Automatic backwashing of the filter was required and problems were encountered with blockages of the process aeration grid. Tertiary nitrification achieved greater than 90% ammoniacal nitrogen (NH3-N) removal at volumetric loading rates up to 0.58 kg NH3-N/m3.d (0.63 kg KJN/m3.d). The economic evaluation indicated that costs of sewage treatment using the BIOCARBONE process would be comparable to those of the activated sludge process for sewage treatment works greater than 50,000 population equivalent. The results show that the BIOCARBONE process is suitable for both the carbonaceous oxidation of settled sewage and the tertiary nitrification of secondary effluent. The process may be an economic option for large sewage treatment works in the UK.


2003 ◽  
Vol 48 (2) ◽  
pp. 291-297 ◽  
Author(s):  
R.J. Craggs ◽  
C.C. Tanner ◽  
J.P.S. Sukias ◽  
R.J. Davies-Colley

Waste stabilisation ponds (WSPs) have been used for the treatment of dairy farm wastewater in New Zealand since the 1970s. The conventional two pond WSP systems provide efficient removal of wastewater BOD5 and total suspended solids, but effluent concentrations of other pollutants including nutrients and faecal bacteria are now considered unsuitable for discharge to waterways. Advanced Pond Systems (APS) provide a potential solution. A pilot dairy farm APS consisting of an Anaerobic pond (the first pond of the conventional WSP system) followed by three ponds: a High Rate Pond (HRP), an Algae Settling Pond (ASP) and a Maturation Pond (which all replace the conventional WSP system facultative pond) was evaluated over a two year period. Performance was compared to that of the existing conventional dairy farm WSP system. APS system effluent quality was considerably higher than that of the conventional WSP system with respective median effluent concentrations of BOD5: 34 and 108 g m-3, TSS: 64 and 220 g m-3, NH4-N: 8 and 29 g m-3, DRP: 13 and 17 g m-3, and E. coli: 146 and 16195 MPN/100 ml. APS systems show great promise for upgrading conventional dairy farm WSPs in New Zealand.


2008 ◽  
Vol 57 (3) ◽  
pp. 361-366 ◽  
Author(s):  
Nidal Mahmoud ◽  
Grietje Zeeman ◽  
JulesB. van Lier

High rate anaerobic technologies offer cost-effective solutions for “sewage” treatment in the temperate climate of Palestine and Jordan. However, local sewage characteristics demand amendments to the conventional UASB reactor design. A solution is found in a parallel operating digester unit that stabilises incoming solids and enriches the UASB sludge bed with methanogenic activity. The digester operational conditions were assessed by operating eight CSTRs fed with primary sludge. The results showed a high degree of sludge stabilization in the parallel digesters at SRTs≥10 and 15 days at process temperatures of 35 and 25°C, respectively. The technical feasibility of the UASB-digester combination was demonstrated by continuous flow pilot-scale experiments. A pilot UASB reactor was operated for 81 days at 6 hours HRT and 15°C and was fed with raw domestic sewage. This period was subsequently followed by an 83 day operation period incorporating a parallel digester unit, which was operated at 35°C. The UASB-digester combination achieved removal efficiencies of total, suspended, colloidal and dissolved CODs of respectively 66, 87, 44 and 30%. Preliminary model calculations indicated that a total reactor volume of the UASB-digester system corresponding to 8.6 hours HRT might suffice for sewage treatment in Palestine.


Desalination ◽  
2007 ◽  
Vol 216 (1-3) ◽  
pp. 174-182 ◽  
Author(s):  
Arnaldo Sarti ◽  
Bruna S. Fernandes ◽  
Marcelo Zaiat ◽  
Eugenio Foresti

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