Milk House Wastewater Research Articles

Blue and Grey Water Footprints of Dairy Farms in Kuwait

In Kuwait, dairy farming faces challenges due to its significant water demands. The current study assessed seasonal patterns of water use to estimate the blue water footprint (WF) and grey WF per kg of fat protein corrected milk (FPCM) for confined dairy farming systems in Kuwait. Blue and grey WFs were evaluated using data from three operational farms. The average blue WF (L·kg-1 FPCM) was estimated to be 54.5 ± 4.0 L·kg-1 in summer and 19.2 ± 0.8 L·kg-1 in winter. The average grey WF (generated from milk house wastewater) was assessed on bimonthly basis and determined based on its phosphate (PO4) concentration (82.2 ± 14.3 mg·L-1) which is the most limiting factor to be 23.0 ± 9.0 L·kg-1 FPCM d-1. The outcomes indicate that enhancing the performance of dairy cows and adopting alternative water management strategies can play a role in minimizing the impacts of confined dairy farming systems in Kuwait on water quality and quantity.

Aerobic and Media Filter Treatment Systems for Milk House Wastewater on Small Dairy Operations

Four different aerobic treatment systems were installed downstream of one or more septic tanks to treat milk house wastewater on nine dairy farms with between 41 and 130 cows. Seven farms had pipeline milking systems, one farm had a flat parlor and one had a milking parlor where parlor wash water entered the milk house wastewater treatment system. Two Biomicrobics FAST systems, two NCS Nibbler systems, three Pirana units, and two Reactor Dynamics, Inc. DYNO2 units were installed. System performance was monitored over 1 to 2 years by measuring water use and collecting wastewater samples.

Treatment of Dairy Farm Effluents Using a Settling Tank and Reed Beds: Performance Analysis of a Farm-Scale System

Effluents from intensive dairy farming should be treated to prevent water pollution. A full-scale integrated treatment system was developed at Poisy in the French Alps. The treatment system consists of an aerated settling tank followed by vertical-flow reed beds planted with common reed. Recirculation of reed bed effluent to the settling tank was used to reduce the concentrations of pollutants within the system. Dairy farm effluents included dairy manure, milk house wash water, manure storage runoff, and at times small amounts of waste milk. Mean inflow rate for milk house wastewater was 5,000 L d-1 (+50 L of waste milk). During periods of heavy rainfall, inflow rates of up to 35,000 L d-1 were observed due to runoff from yard areas. To improve treatment performance, an aeration system was installed in the settling tank in May 2006. Mass removals increased by more than 10% for organic pollutants due mainly to aeration. Mean load removals ranged from 82% to 96% for organic and solid pollutants. Mean total nitrogen and phosphorus removals were 76% and 19%, respectively. Sludge accumulation on the reed beds was 2.2 cm year-1. Sludge quality conformed to French land application regulations.

Hydraulic performance of a mature wetland treating milkhouse wastewater and agricultural runoff

A tracer study is an efficient method of determining flow dynamics within a constructed wetland. In previous studies, a number of tracer studies have been carried out on various constructed wetlands covering a wide range of configurations. From these tracer studies it is evident that all constructed wetlands perform differently and generally with less efficiency than assumed by theoretical design computations. During the summer of 2004, a tracer study was performed on a constructed wetland located in Embrun, Ontario (Canada) treating milkhouse wastewater and agricultural runoff to determine its actual hydraulic performance. Sediment height and vegetation density profiles were also obtained and examined to explain the preferential flow pathways that were observed during the tracer analysis. It was determined that the constructed wetland had an effective treatment area representing 79% of the total area, and that the hydraulic efficiency of the system was 74%. Examination of the sediment height and vegetation density profiles resulted in no evidence of physical pathways that could be attributed to the establishment of preferential flow. The hydraulic efficiency was therefore attributed to the inflow and outflow layout of the constructed wetland cell, combined with wind induced mixing.

Milk House Wastewater Flows and Characteristics for Small Dairy Operations

Water meters were used to indicate milk house wastewater flow rates in the milk houses of 16 dairy operations with between 41 and 130 milking cows. Wastewater samples (7 to 21) were taken from the first septic tank providing primary treatment of the milk house water to measure pH, biochemical oxygen demand (BOD5), chemical oxygen demand (COD), total suspended solids (TSS), fats, oils and grease (FOG), total phosphorus, total Kjeldahl nitrogen (TKN), and ammonia nitrogen concentrations. Average water flow rates across the 14 dairy operations without parlors ranged from 8.6 to 35.3 L/d/cow. Milk house water use per cow per day on individual farms varied by between 146% and 400%. Overall average BOD5 concentration across all sixteen operations was 1.44 g/L while individual farm averages ranged from 0.50 to 4.52 g/L. Overall average COD concentration was 2.26 g/L; farm averages ranged from 0.72 to 6.28 g/L. Overall average TSS concentration across all operations was 686 mg/L, farm averages ranged from 181 to 1,537 mg/L. Average FOG concentration was 477 mg/L, farm averages ranged from 45 to 1,334 mg/L. Median average pH level was 6.8, farm levels ranged from 5.9 to 8.0. Average phosphorus concentration across all operations was 56 mg/L, farm averages ranged from 18 to 101 mg/L. Average TKN concentration was 81 mg/L, farm averages ranged from 33 to 179 mg/L. Average ammonia concentration was 34 mg/L, farm averages ranged from 12 to 98 mg/L. Based on these results the authors recommend using 19 L/d/cow for the design milk house wastewater flow rate for milk houses for dairy operations with 130 or fewer cows. For sizing aerobic treatment units and infiltration systems, the authors recommend using 1.5 g/L for the design effluent BOD5 concentration for a milk house only. For designing irrigation land application systems based on annual TKN and P per cow for milk house only sites, the authors recommend using 0.6 and 0.35 kg/cow/yr, respectively.

Soil Nutrient Load and Drain Water Quality in Seepage Fields Receiving Milk House Wastewater

The large volume of wastewater generated on dairy farms from the cleaning of milk pipelines and milking equipment contains nutrients and microorganisms that could pollute waterways if discharged without treatment. The objective of this study was to evaluate a modified septic tank-seepage field system for disposing of milk house wastewater, by measuring the accumulation of nutrients in the soil and monitoring the water drained from the seepage field. The study was conducted on two small dairy farms (40–50 milking cows) in south-west Quebec, Canada. After passing through a sediment and milk fat trap and then the septic tank, the milk house wastewater was drained into a 0.45 ha experimental seepage field under pasture or arable cropped land. Much larger than a conventional seepage bed (0.025 ha), the experimental seepage field was designed to remain recycle the wastewater nutrients and water, while preventing soil saturation. Annual nutrient loading from milk house wastewaters were, on average, 60 kg total N ha−1, 50 kg total P ha−1 and 80 kg total K ha−1. The concentrations of plant-available nutrients increased when milk house wastewater entered the seepage field, but the magnitude of change was farm-specific, due to the unique topography and soil characteristics offered by each farm. For instance, the P concentration was unchanged on one farm, but there was rapid and significant accumulation of P in the 20–60 cm depth of the soil profile on the second farm. There was an increase in Ca and Mg concentrations in the soil profile on both farms, but soil salinity remained <4 dS m−1 during this study. Water drained from the experimental seepage fields was similar in quality to that drained from a control area, indicating that the seepage fields were sufficiently large to adsorb and treat the nutrients contained in milk house wastewater in the short-term. Assessment of the cation and anion adsorption capacity of soils on these farms will be necessary to verify the treatment capacity and effective lifespan of the seepage fields.

Surface Irrigation of Dairy Farm Effluent, Part I: Nutrient and Bacterial Load

When handled separately from manures, dairy farm effluents (DE) are costly to manage because of their low nutrient content and large volume. In anticipation of using surface irrigation to lower the land application cost of DE, this projects investigated the impact, on DE characteristics, of different sources and storage systems. Milk house wastewaters were monitored on two farms using a 500l manhole intercepting these before entering the septic tank. Manure runoff, with and without milk house wastewater, was also characterised on six farms for 1 yr, and on two farms for three consecutive years, where each farm used a different management system. The results indicated that DE containing milk house wastewater, manure runoff or a mixture of both had a relatively low nutrient load, confirming that their application rate needed to range between 205 and 2050 m 3 ha � 1 , depending on the management system used. Stored along with solid manure, DE generally had a higher total solids (TS), nutrient loads and bacterial count, as compared to that drained away from the solid manure. Furthermore, for effluent drained away from solid manures, rainfall rather than snow occurring from October to May, inclusively, tended to increase their TS and nutrient load. The ratio of faecal coliforms to faecal streptococci (FC/FS) was greater than 1� 0 when milk house wastewaters were stored along with the manure runoff because milk house wastewaters increased the death rate for FS compared to FC.

Seasonal performance of a wetland constructed to process dairy milkhouse wastewater in Connecticut

Constructed wetlands are gaining increased attention for treatment of nonpoint sources of water pollution. Although constructed wetlands have been utilized for wastewater treatment in warm climates, their performance in cold climates has been questioned. A surface-flow wetland, designed to treat 2.65 m 3 d −1 of milkhouse wastewater, was constructed on the University of Connecticut’s Storrs campus in 1994. The purpose of the project was to determine the efficiency of the system in reducing nitrogen, phosphorus, five-day biochemical oxygen demand (BOD 5), total suspended solids (TSS), and fecal coliform bacteria (FC). The wetland was designed to process an estimated BOD 5 loading rate of 7.3 g m −2 d −1, which was less than half of the average actual loading rate. The overall percentage of mass retention was 94, 85, 68, 60 and 53% for TSS, BOD 5, total phosphorus, nitrate–nitrite and total Kjeldahl-nitrogen, respectively. Although the wetland became a net source of ammonia nitrogen (NH 3–N) following plant die back in fall 1994, NH 3–N outflow concentrations have gradually declined over time. Mass retention was significantly greater ( P<0.05) during the summer than during the winter for all variables except FC. Denitrification rates measured using the acetylene block method have shown denitrification to be a minor removal mechanism (<1%) for nitrogen in this wetland. The mass balance indicated that settling and increased storage was the largest removal mechanism. The treatment of wastewater in this wetland did not meet design outflow concentration criteria, most likely due to BOD 5 overloading.

Seasonal effectiveness of a constructed wetland for processing milkhouse wastewater

Constructed wetlands are gainign increased attention for treatment of nonpoint source pollution. Although constructed wetlands have been used for wastewater treatment in warm climates, their performance in cold climates has been questioned. A surface-flow wetland, designed to treat 2.65 m3d−1 of milkhouse wastewater, was constructed on the University of Connecticut’s Storrs campus in 1994. The purpose of the project was to determine the efficiency of the system to reduce nutrients, five-day biochemical oxygen demand (BOD5), bacteria, and total suspended solids and to reduce fecal coliform bacteria. During the first ten months of operation, outflow volume was 90% of inflow. Although the wetland was designed to process a BOD5 loading rate of 1500 mg/L, the average actual loading rate was 3000 mg/L. The overall percent mass retention of total suspended solids was 45% and for nutrients was 28%, 27%, 47%, and 6%, for total phosphorus, total Kjeldahl-N, nitrate-N, and ammonia-N, respectively. The percent reduction of fecal coliform and BOD5 was 31% and 28% respectively. Mass retention was significantly greater (p < 0.05) during the growing season than during plant senescence for total suspended solids, total phosphorus, total Kjeldahl, ammonia, and nitrate/nitrite nitrogen. Effluent ammonia nitrogen concentrations often exceeded influent values during the winter. Preliminary indications are that the treatment of the wastewater does not meet design standards, especially in the winter, probably due to overloading of BOD5.

Influence of organic matter from waste water on the permeability of membranes

The progress in the development of membranes for the treatment of aqueous solutions in the last years has attracted much interest in this technology. In order to find out the application limits, for example by ultrafiltration and reverse osmosis for waste water, research was carried out into the influence of organic matter, expressed as chemical oxygen demand (COD), on the permeability of the membrane on a pilot-scale. Different waste waters (pig and cattle slurry, milkhouse waste water and vegetable wash water) with different concentrations of organic matter were treated by ultrafiltration, and the permeates were treated partly by reverse osmosis. These tests as well as experiments for ultrafiltration with anaerobically treated mixtures of pig slurry and potato wash water showed that the permeability of membranes is determined by the concentration of organic matter of waste water and is independent of the kind of waste water. By ultrafiltration of different waste waters with an anorganic silicon-carbide membrane with a nominal pore diameter of 0.05 μm for example, the permeability decreased from 158 l/m 2 ∗ h to 26 l/m 2 ∗ h when the COD-concentration increased from 0.63 g/l to 42.8 g/l, respectively.

5562829 Process for clarifying milkhouse wastewater : Malcolm Ian; Weil Claude; Kollaard William Ottawa, Canada assigned to Agricultural Research Institute of Ontario

5562829 Process for clarifying milkhouse wastewater : Malcolm Ian; Weil Claude; Kollaard William Ottawa, Canada assigned to Agricultural Research Institute of Ontario

Vegetative Filter Treatment of Dairy Milkhouse Wastewater

AbstractA vegetated filter strip constructed to treat milkhouse wastewater from a Vermont dairy farm was evaluated to determine its effectiveness in reducing solids, P and N concentrations and exports in surface and subsurface flow. The liquid waste was applied twice daily via a level lip spreader at a rate of 2.94 cm/wk on a vegetated loam soil having a 2% slope. The flow and concentrations of inputs and surface and subsurface outputs were continuously monitored during the 2‐yr study. The strip significantly (P &lt; 0.01) reduced solids, P, and N on a concentration basis, and retained 95% solids, 89% P, and 92% N on a mass basis. Retention was the greatest during the growing season and the poorest during snowmelt periods. Concentrations in subsurface outputs were greater than in surface runoff and over 75% of the mass export was in subsurface flow. Comparisons of this study with values reported in the literature suggests that hydraulic loading rate governs the effectiveness of filter strip treatment.