Nitrification potential of attached biofilms in dairy farm waste stabilisation ponds

2000 ◽  
Vol 42 (10-11) ◽  
pp. 195-202 ◽  
Author(s):  
R. J. Craggs ◽  
C. C. Tanner ◽  
J. P. Sukias ◽  
R. J. Davies-Colley
Keyword(s):  
New Zealand ◽  
Dairy Farm ◽  
Pond Water ◽  
Oxygen Availability ◽  
Ammonia Toxicity ◽  
Waste Stabilisation Ponds ◽  
Nitrification Potential ◽  
N Removal ◽  
Mechanical Aeration ◽  
Farm Waste

Dairy farm waste stabilisation ponds are a major source of ammoniacal-N to surface waters in New Zealand. Ammoniacal-N is of particular concern in New Zealand where native aquatic invertebrates appear to be very sensitive to ammonia toxicity. This paper investigates improvement of ammoniacal-N nitrification in dairy farm facultative ponds with mechanical aeration and provision of biofilm attachment surfaces. Biofilm was grown on surfaces at different depths (0.1 m, 0.2 m and 0.6 m) under three mechanical aeration regimes (no aeration, night-only aeration and continuous aeration). Nitrification potential of biofilm was determined as the rate of ammoniacal-N removal in bioassays with ammoniacal-N spiked pond water or culture medium under controlled conditions (20°C, pH 7.0, constant stirring, DO 2–3 g m−3, dark). The nitrification potentials (0.30 g N m−2 biofilm d−1 to 2.17 g N m−2 biofilm d−1) of biofilm-coated surfaces were largely controlled by oxygen availability and consistency of supply in the pond. Nitrification potentials were high where oxygen availability was high, such as close to the pond surface where atmospheric re-aeration and algal photosynthesis were prevalent. Nitrification potentials of biofilms incubated at depth were enhanced by mechanical aeration, with higher values achieved under the continuous aeration regime and at more turbulent sites closer to the aerator.

Biogas production from anaerobic waste stabilisation ponds treating dairy and piggery wastewater in New Zealand

2007 ◽  
Vol 55 (11) ◽  
pp. 257-264 ◽  
Author(s):  
J.B.K. Park ◽  
R.J. Craggs
Keyword(s):  
New Zealand ◽  
Energy Recovery ◽  
Biogas Production ◽  
Ghg Emissions ◽  
Dairy Farm ◽  
Gas Production ◽  
Dairy Wastewater ◽  
Average Volume ◽  
Piggery Wastewater ◽  
Waste Stabilisation Ponds

New Zealand has over 1000 anaerobic wastewater stabilisation ponds used for the treatment of wastewater from farms and industry. Traditional anaerobic ponds were not designed to optimise anaerobic digestion of wastewater biomass to produce biogas and these uncovered ponds allowed biogas to escape to the atmosphere. This release of biogas not only causes odour problems, but contributes to GHG (greenhouse gas) emissions and is wasteful of energy that could be captured and used. Biogas production from anaerobic stabilisation ponds treating piggery and dairy wastewater was measured using floating 25 m2 HDPE covers on the pond surface. Biogas composition was analysed monthly and gas production was continually monitored. Mean areal biogas (methane) production rates from piggery and dairy anaerobic ponds were 0.78 (0.53) m3/m2/d and 0.03 (0.023) m3/m2/d respectively. Average CH4 content of the piggery and dairy farm biogas were 72.0% and 80.3% respectively. Conversion of the average volume of methane gas that could be captured from the piggery and dairy farm ponds (393.4 m3/d and 40.7 m3/d) to electricity would reduce CO2 equivalent GHG emissions by 5.6 tonnes/d and 0.6 tonnes/d and generate 1,180 kWh/d and 122 kWh/d. These results suggest that anaerobic ponds in New Zealand release considerable amounts of GHG and that there is great potential for energy recovery.

Dairy farm wastewater treatment by an advanced pond system

2003 ◽  
Vol 48 (2) ◽  
pp. 291-297 ◽  
Author(s):  
R.J. Craggs ◽  
C.C. Tanner ◽  
J.P.S. Sukias ◽  
R.J. Davies-Colley
Keyword(s):  
New Zealand ◽  
Dairy Farm ◽  
High Rate ◽  
Great Promise ◽  
E Coli ◽  
Effluent Quality ◽  
Waste Stabilisation Ponds ◽  
Faecal Bacteria ◽  
Period Performance ◽  
Farm Wastewater

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.

Combined photosynthesis and mechanical aeration for nitrification in dairy waste stabilisation ponds

2003 ◽  
Vol 48 (2) ◽  
pp. 137-144 ◽  
Author(s):  
J.P.S. Sukias ◽  
R.J. Craggs ◽  
C.C. Tanner ◽  
R.J. Davies-Colley ◽  
J.W. Nagels
Keyword(s):  
Electrical Power ◽  
Oxygen Demand ◽  
Aquatic Organisms ◽  
Ammonia Toxicity ◽  
Nitrifying Bacteria ◽  
Matched Pair ◽  
Total N ◽  
N Removal ◽  
Algal Photosynthesis ◽  
Mechanical Aeration

New Zealand has 16,500 dairy farms (avg. 220 cows), with cows kept on pasture throughout the year. During the 9-month dairy season, the cows are milked twice a day (averaging 2.5-3 h per day in the dairy parlour). Urine and faecal wastes deposited in the dairy parlour are washed away with high pressure hoses, using large volumes of water. A common method of treatment is in simple two-pond (anaerobic/facultative) lagoon systems, which remove about 95% of suspended solids and BOD5, but only 75% of total-N prior to discharge. High concentrations of ammoniacal-N in the effluent can cause toxicity to aquatic organisms in receiving waters. Mechanical aeration of the second (facultative) lagoon to promote nitrification improves effluent quality by reducing oxygen demand and potential ammonia toxicity to streamlife. Mechanical aeration however is associated with considerable mixing, which may prevent algae from optimising photosynthesis in the facultative lagoon. A series of experiments was undertaken which tested the efficiency of mechanical aeration and then attempted to combine it with daytime algal oxygen production in order to maximise ammonia conversion to nitrate, while minimising costs to the farmer. An experimental facility was developed by dividing a large facultative lagoon into two, producing a matched pair of lagoons, operated in parallel with influent flow split equally. Over successive dairy seasons, various aeration regimes were compared. Continuous aeration promoted nearly complete nitrification of the ammoniacal-N (99% removal), and effluent BOD was approximately halved. However the continuous mixing reduced algal biomass, and thus daytime algal photosynthesis. Night-only aeration permitted greater algal photosynthesis to occur, as well as halving electrical power consumption. Ammoniacal-N removal reduced to 90% (10 g m-3 remaining in the effluent), while BOD removal was also lower than in the continuously aerated lagoon (59 and 69% respectively). Providing a series of biofilm attachment surfaces for nitrifying bacteria by suspending geotextile material close to the surface in the pond in consistently aerobic water resulted in improved ammoniacal-N removal efficiency (93%) with night aeration, but still lower removal than continuous aeration.

Methane emissions from anaerobic ponds on a piggery and a dairy farm in New Zealand

2008 ◽  
Vol 48 (2) ◽  
pp. 142 ◽  
Author(s):  
R. Craggs ◽  
J. Park ◽  
S. Heubeck
Keyword(s):  
New Zealand ◽  
Methane Production ◽  
Biogas Production ◽  
Ghg Emissions ◽  
Dairy Farm ◽  
Pond Water ◽  
Visual Observation ◽  
Methane Production Rate ◽  
Surface Conversion

Over 1000 anaerobic ponds are used in the treatment of wastewater from farms and industry in New Zealand. These anaerobic ponds were typically designed as wastewater solids holding ponds rather than for treatment of the wastewater. However, visual observation of these uncovered ponds indicates year-round anaerobic digestion and release of biogas to the atmosphere. The release of biogas may be associated with odour nuisance, contributes to greenhouse gas (GHG) emissions and is a waste of potentially useful energy. The aim of this study was to measure the seasonal variation in quantity and quality of biogas produced by an anaerobic pond at a piggery (8000 pigs) and a dairy farm (700 cows). Biogas was captured on the surface of each anaerobic pond using a floating 25 m2 polypropylene cover. Biogas production was continually monitored and composition was analysed monthly. Annual average biogas (methane) production rates from the piggery and dairy farm anaerobic ponds were 0.84 (0.62) m3/m2.day and 0.032 (0.026) m3/m2.day, respectively. Average CH4 content of the piggery and dairy farm biogas was high (74% and 82%, respectively) due to partial scrubbing of CO2 within the pond water. The average daily volume of methane gas that could potentially be captured by completely covering the surface of the piggery and dairy farm anaerobic ponds was calculated as ~550 m3/day and ~45 m3/day, respectively (assuming that the areal methane production rate was uniform across the pond surface). Conversion of this methane to electricity would generate 1650 kWh/day and 135 kWh/day, respectively (with potentially 1.5 times these values co-generated as heat) and reduce GHG emissions by 8.27 t CO2 equivalents/day and 0.68 t CO2 equivalents/day, respectively. These preliminary results suggest that conventional anaerobic ponds in New Zealand may release considerable amounts of methane and could be a more significant point source of GHG emissions than previously estimated. Further studies of pond GHG emissions are required to accurately assess the contribution of wastewater treatment ponds to New Zealand’s total GHG emissions.

Tree Species for Recovering Nitrogen from Dairy-Farm Effluent in New Zealand

2001 ◽  
Vol 30 (3) ◽  
pp. 1064-1070 ◽  
Author(s):  
Jon K.F. Roygard ◽  
Brent E. Clothier ◽  
Steve R. Green ◽  
Nanthi S. Bolan
Keyword(s):  
New Zealand ◽  
Tree Species ◽  
Dairy Farm

scholarly journals Still ‘dairy farm fever’? A Bayesian model for leptospirosis notification data in New Zealand

2021 ◽  
Vol 18 (175) ◽  
pp. 20200964
Author(s):  
Jackie Benschop ◽  
Shahista Nisa ◽  
Simon E. F. Spencer
Keyword(s):  
New Zealand ◽  
Public Health Surveillance ◽  
Dairy Farm ◽  
Nucleic Acid Detection ◽  
Dairy Farmers ◽  
Occupational Groups ◽  
Specific Occupation ◽  
Health Surveillance Data ◽  
Notification Data ◽  
Important Evidence

Routinely collected public health surveillance data are often partially complete, yet remain a useful source by which to monitor incidence and track progress during disease intervention. In the 1970s, leptospirosis in New Zealand (NZ) was known as ‘dairy farm fever’ and the disease was frequently associated with serovars Hardjo and Pomona. To reduce infection, interventions such as vaccination of dairy cattle with these two serovars was implemented. These interventions have been associated with significant reduction in leptospirosis incidence, however, livestock-based occupations continue to predominate notifications. In recent years, diagnosis is increasingly made by nucleic acid detection which currently does not provide serovar information. Serovar information can assist in linking the recognized maintenance host, such as livestock and wildlife, to infecting serovars in human cases which can feed back into the design of intervention strategies. In this study, confirmed and probable leptospirosis notification data from 1 January 1999 to 31 December 2016 were used to build a model to impute the number of cases from different occupational groups based on serovar and month of occurrence. We imputed missing occupation and serovar data within a Bayesian framework assuming a Poisson process for the occurrence of notified cases. The dataset contained 1430 notified cases, of which 927 had a specific occupation (181 dairy farmers, 45 dry stock farmers, 454 meatworkers, 247 other) while the remaining 503 had non-specified occupations. Of the 1430 cases, 1036 had specified serovars (231 Ballum, 460 Hardjo, 249 Pomona, 96 Tarassovi) while the remaining 394 had an unknown serovar. Thus, 47% (674/1430) of observations had both a serovar and a specific occupation. The results show that although all occupations have some degree of under-reporting, dry stock farmers were most strongly affected and were inferred to contribute as many cases as dairy farmers to the burden of disease, despite dairy farmer being recorded much more frequently. Rather than discard records with some missingness, we have illustrated how mathematical modelling can be used to leverage information from these partially complete cases. Our finding provides important evidence for reassessing the current minimal use of animal vaccinations in dry stock. Improving the capture of specific farming type in case report forms is an important next step.

scholarly journals Coupling hydrothermal liquefaction and membrane distillation to treat anaerobic digestate from food and dairy farm waste

2018 ◽  
Vol 267 ◽  
pp. 408-415 ◽  
Author(s):  
Unnati Rao ◽  
Roy Posmanik ◽  
Lindsay E. Hatch ◽  
Jefferson W. Tester ◽  
Sharon L. Walker ◽  
...  
Keyword(s):  
Dairy Farm ◽  
Membrane Distillation ◽  
Hydrothermal Liquefaction ◽  
Anaerobic Digestate ◽  
Farm Waste

Waste stabilisation ponds upgrading at Blenheim and Seddon, New Zealand - case studies

2003 ◽  
Vol 48 (2) ◽  
pp. 17-23
Author(s):  
H.E. Archer ◽  
S.A. Donaldson
Keyword(s):  
Wastewater Treatment ◽  
New Zealand ◽  
Lower Cost ◽  
Small Communities ◽  
Large Cities ◽  
Effluent Quality ◽  
Waste Stabilisation Ponds ◽  
Bank Protection ◽  
In Series ◽  
Final Effluent

Waste stabilisation ponds (WSP) have been a popular form of wastewater treatment in New Zealand both for large cities and small communities. Most WSP were constructed from 1960 to 1985 and were single ponds or a primary and secondary pond in series of similar size. Since 1995, improvements comprising primary and maturation ponds, with four to six cells in series have been constructed or retrofitted to original two cell ponds. The Seddon and Blenheim ponds include in-bank rock filters between maturation cells as a lower cost way of providing this feature for reduction of solids. Operating results show reduced variability in final effluent quality for BOD and SS. In addition, very good reductions of faecal coliform and enterococci have been achieved along with good reductions of ammonia and total nitrogen for most of the year except the middle of winter. Extensive use of rock as rip-rap bank protection and in the rock filters, appears to have provided sufficient extra surface area for a nitrifying biofilm to develop.

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