Dairy Manure Effluent Research Articles

Effectiveness of Biochar for Sorption of Ammonium and Phosphate from Dairy Effluent

The use of biochar for recovery of excess nutrients in dairy manure effluent and the use of nutrient-enriched biochar as soil amendment can offer a robust solution for multiple environmental issues. In this study we determined the capacity of biochar, produced by pyrolyzing mixed hardwood feedstock at 300°C, to adsorb and retain or release two major nutrient ions: ammonium (NH) and phosphate (PO). We conducted the experiment using a range of nutrient concentrations that represent those commonly observed in dairy manure effluent (0-50 mg L for PO and 0-1000 mg L for NH). Up to 5.3 mg g NH and 0.24 mg g PO was adsorbed from manure by biochar (18 and 50% of total amount in the manure slurry, respectively). During the desorption phase of the experiment, biochar retained 78 to 91% of the sorbed NH and 60% of the sorbed PO at reaction times <24 h. Our findings confirm that biochar can be used for recovering excess nitrogen and phosphorus from agricultural water, such as dairy manure effluent.

Phosphorus Uptake by Potato from Biochar Amended with Anaerobic Digested Dairy Manure Effluent

Sorption of plant nutrients from dairy storage lagoons by biochar and use as a supplemental fertilizer is a beneficial strategy to reduce nutrient contamination around dairies and supply nutrients to potato (Solanum tuberosum L.) and other crops. This research evaluated potato growth responses and P partitioning from several rates of P applied as either mono‐ammonium phosphate (MAP) or as P recovered from anaerobic digested dairy manure using biochar. Single‐stemmed plants of the potato cultivars Ranger Russet and Umatilla Russet were grown in 7‐L pots containing Quincy sand soil (mixed, mesic Xeric Torripsamment). Biochar amended with dairy effluent applied at 5.7 and 11.4 Mg ha–1 with fertilizer application rates equivalent to 55 and 110 kg P ha–1 maintained adequate P levels in potato petioles of both cultivars through 85 d after planting. Total plant P uptake was greater for treatments receiving MAP. Total potato biomass and tuber yields of Umatilla Russet were 30 and 27% lower when amended with basic or enriched biochar compared to MAP treatments, respectively. Tuber biomass declined 10 and 20% for Ranger Russet and Umatilla Russet for the 11.4 Mg ha–1 amended biochar, respectively compared to MAP fertilized treatments. Similar declines were found for the aboveground biomass and roots. The 5.7 Mg ha–1 of enriched biochar supplied 70 to 80% of the P requirement for potato growth. These findings are an important step in providing evidence of the benefits of using recovered P as a fertilizer supplement to reduce the reliance on rock phosphates.

Impact of Biochar Enriched with Dairy Manure Effluent on Carbon and Nitrogen Dynamics

Amending soils with biochar can have multiple environmental benefits, including improvement in soil physicochemical properties, carbon sequestration, reduction in leaching losses of essential nutrients, and reduction in greenhouse gas (GHG) emissions. This study was conducted to determine the effect of enriched biochar amendments on leaching losses of essential nutrients and GHG emissions from soil. The enriched biochar was prepared by shaking biochar with dairy manure effluent for 24 h, which increased the C and N concentration of biochar by 9.3 and 8.3%, respectively. Incubation and leaching experiments were conducted for 8 wk with three treatments: soil, soil + 1% biochar, and soil + 1% enriched biochar. Amendment with biochar and enriched biochar relative to unamended soil resulted in 68 and 75% reduction in net nitrification, 221 and 229% reduction in net ammonification, 67 and 68% reduction in cumulative CO flux, respectively, and 26% reduction in cumulative NO flux for both biochar treatments. There were no significant differences among treatments in total leaching losses of C, N, and base cations. Our findings suggest that enrichment of biochar with dairy manure effluent can promote C and N storage in soil and provide additional environmental benefits.

Evaluation of Ultrasonic Pretreatment on Anaerobic Digestion of Different Animal Manures

This article addresses the effect of ultrasonication as a pretreatment to anaerobic digestion of four types of animal manure, including swine slurry, beef feedlot manure, dairy manure slurry, and separated dairy manure effluent. The effect of ultrasonication on soluble chemical oxygen demand (SCOD) and biochemical methane potential (BMP) were determined, and the energy efficiency of ultrasonic pretreatment was evaluated. Ultrasonic pretreatment was applied at two amplitudes (80 and 160 µmpp) and at two time settings (15 and 30 s) to each of the four manure types. The SCOD of each manure sample was determined before and after ultrasonic pretreatment. In addition, BMP trials were run on each waste with and without ultrasonic pretreatment. As part of the BMP, biogas production was measured and analyzed for methane content and cumulative methane production. Ultrasonic pretreatment of swine slurry, beef feedlot manure, dairy manure slurry, and separated dairy manure effluent increased the average SCOD up to 23%, 92%, 59%, and 33%, respectively, and the average methane yield up to 56%, 43%, 62%, and 20%, respectively. Increasing the ultrasonic amplitude and treatment time resulted in an increase in manure SCOD and methane production; the greatest methane production was obtained using the ultrasonic pretreatment at the highest power and longest treatment time. The observed greatest methane production from swine slurry, beef feedlot manure, dairy manure slurry, and separated dairy manure effluent were 394, 230, 226, and 340 mL CH4 g-1 VS, respectively. In contrast, the greatest energy efficiency was obtained with the lowest ultrasonic amplitude combined with the shortest treatment time.

Optimization of an Oil Extraction Process for Algae from the Treatment of Manure Effluent

AbstractIncreasing interest in the coupling of biological wastewater treatment processes with the generation of value‐added products (such as oil containing ω‐3 fatty acids (FA)) has stimulated efforts in adapting extraction methods for treatment byproducts. This study’s objective was to compare a high temperature/pressure extraction method (accelerated solvent extraction) (ASE) and a manual extraction method (modified Folch extraction) with regard to their ability to extract total oil from three algae samples from the treatment of dairy manure effluent. The efficiency of total oil and FA extraction with three solvents (chloroform/methanol, isopropanol/hexane, and hexane) was also evaluated using the ASE method. Results showed that the ASE method yielded higher values for total oil content compared to the Folch method but similar values for FA content and composition after four extraction cycles with chloroform/methanol. However, the ASE method yielded much higher amounts of FA in the first cycle (85–95% of total extracted) compared to the Folch method (44–55% of total extracted in the first cycle). As expected, the extraction efficiency of the ASE method for FA was dependent on the extraction solvent. FA content values using ASE with chloroform/methanol &gt; isopropanol/hexane &gt; hexane. FA content values using the Folch method or ASE with chloroform/methanol were not significantly influenced by sample particle size within the size range of 0.1–1 mm.

Treatment of dairy manure effluent using freshwater algae: Algal productivity and recovery of manure nutrients using pilot-scale algal turf scrubbers

Cultivating algae on nitrogen (N) and phosphorus (P) in animal manure effluents presents an alternative to the current practice of land application. The objective of this study was to determine values for productivity, nutrient content, and nutrient recovery using filamentous green algae grown in outdoor raceways at different loading rates of raw and anaerobically digested dairy manure effluent. Algal turf scrubber raceways (30 m 2 each) were operated in central Maryland for approximately 270 days each year (roughly April 1–December 31) from 2003 to 2006. Algal biomass was harvested every 4–12 days from the raceways after daily additions of manure effluent corresponding to loading rates of 0.3 to 2.5 g total N (TN) and 0.08 to 0.42 g total P (TP) m −2 d −1. Mean algal productivity values increased from approximately 2.5 g DW m −2 d −1 at the lowest loading rate (0.3 g TN m −2 d −1) to 25 g DW m −2 d −1 at the highest loading rate (2.5 g TN m −2 d −1). Mean N and P contents in the dried biomass increased 1.5–2.0-fold with increasing loading rate up to maximums of 7% N and 1% P (dry weight basis). Although variable, algal N and P accounted for roughly 70–90% of input N and P at loading rates below 1 g TN, 0.15 g TP m −2 d −1. N and P recovery rates decreased to 50–80% at higher loading rates. There were no significant differences in algal productivity, algal N and P content, or N and P recovery values from raceways with carbon dioxide supplementation compared to values from raceways without added carbon dioxide. Projected annual operational costs are very high on a per animal basis ($780 per cow). However, within the context of reducing nutrient inputs in sensitive watersheds such as the Chesapeake Bay, projected operational costs of $11 per kg N are well below the costs cited for upgrading existing water treatment plants.

Biofertilizers from Algal Treatment of Dairy and Swine Manure Effluents

Abstract An alternative practice to land spreading of manure effluents is to grow crops of algae on the nitrogen (N) and phosphorus (P) present in these liquid slurries. The overall environmental and economic values of this approach depend, in part, on the use and value of the resulting algal byproduct. Among the potential uses of algal biomass from such systems is its use as a slow release fertilizer. The objective of this study was to evaluate the fertilizer value of algae that had been grown in laboratory (indoor) and pilot scale (outdoor) algal turf scrubbers using raw dairy manure effluent, anaerobically digested dairy manure effluent and raw swine manure effluent for vegetable production. Results from a multifactorial N-mineralization experiment using soil amended with eight algal biomass treatments showed that approximately 5% of total algal N was present as plant available N at day 0. After 21 and 63 days, the total algal N present as mineral N increased to 25–29% and 36–41%, respectively. Approximately 40% of total algal P was present as Mehlich-3 extractable P throughout the 63-day incubations. Results from plant growth experiments showed that 17 day-old corn (Zea mays L.) seedlings grown in algae-amended potting mixes were equivalent to those grown with comparable levels of fertilizer-amended potting mixes with respect to shoot dry weight and nutrient content. There were no differences in the fertilizer value of different batches of algae at the low rate amendment (-47 kg of available N·ha−1). However, at the high rate amendment (-93 kg of available N·ha−1) shoot biomass, and shoot N and P contents were greatest for treatments containing algae grown using indoor laboratory scale algal turf scrubbers (ATS) units and least for treatments with algae grown outdoors using pilot scale ATS units. Longer term field studies are needed to assess the effect of algal biomass amendment on corn and vegetable yields under a range of growth conditions.

An economic assessment of algal turf scrubber technology for treatment of dairy manure effluent

Controlling the input of nitrogen (N) and phosphorus (P) from dairies and other livestock operations into the surrounding air- and water-sheds poses both technical and economic challenges to the agricultural community. The purpose of this paper is to assess the economics of algal turf scrubber treatment technology at the farm-scale for a hypothetical 1000-cow dairy. Costs were developed for farms with and without anaerobic pretreatment. The majority of capital costs were due to land preparation, installation of liner material, and engineering fees. The majority of operational costs were due to energy requirements for biomass drying, pumping water, and repayment of capital investment. On farms using anaerobic pretreatment, waste heat from burning of biogas could be used to offset the energy requirements of biomass drying. In addition, biogas combustion exhaust gas could then be recycled back to the algal system to supply dissolved inorganic carbon for optimal algal production and pH control. Under the best case (algal system coupled with anaerobic digestion pretreatment), the yearly operational costs per cow, per kg N, per kg P, and per kg of dried biomass were $454, $6.20, $31.10, and $0.70, respectively. Without anaerobic digestion pretreatment, the yearly operational costs were 36% higher, amounting to $631 per cow, $8.70 per kg N, $43.20 per kg P, and $0.97 per kg of dried biomass. For perspective, a recent survey of 36 Maryland dairy farms found long-term annual profits of about $500 per cow. As no market currently exists for manure grown algal biomass, our cost analysis does not include any value of the biomass generated during manure treatment. In addition, there are a variety of potential uses for the algal biomass from manure treatment that could defray treatment costs. Future opportunities for dairies to participate in nutrient trading approaches to watershed nutrient management may also become important.

Treatment of Dairy Manure Effluent Using Freshwater Algae: Elemental Composition of Algal Biomass at Different Manure Loading Rates

The cultivation of algae on nitrogen (N) and phosphorus (P) in animal manure effluents presents an alternative to the current practice of land application. However, the use and value of the resulting algal biomass as a feed or soil supplement depend, in part, on whether the biomass contains any harmful components such as heavy metals. The objective of this study was to determine how the elemental composition of algae changed in response to different loading rates of anaerobically digested flushed dairy manure effluent. Algal biomass was harvested weekly from laboratory-scale algal turf scrubber (ATS) units using four manure loading rates (2, 4, 6, or 9 L m(-2) day(-1)) corresponding to daily loading rates of 0.8-3.7 g of total N and 0.12-0.58 g of total P. Mean N and P contents in the dried biomass increased 1.6-1.8-fold with increasing loading rate up to maximums of 6.5% N and 0.84% P at 6 L m(-2) day(-1). Concentrations of Al, Ca, Cu, Fe, Mg, Mn, and Zn showed similar 1.4-1.8-fold increases up to maximums at a loading rate of 6 L m(-2) day(-1), followed by plateaus or decreases above this loading rate. Concentrations of Cd, Mo, and Pb initially increased with loading rate but then declined to levels comparable to those at the lowest loading rate. Concentrations of Si and K did not increase significantly with loading rate. The maximum concentrations of individual components in the algal biomass were as follows (in mg kg(-)(1)): 1100 (Al), 9700 (Ca), 0.43 (Cd), 56 (Cu), 580 (Fe), 5.0 (Pb), 2300 (Mg), 240 (Mn), 3.0 (Mo), 14,700 (K), 210 (Si), and 290 (Zn). At these concentrations, heavy metals in the algal biomass would not be expected to reduce its value as a soil or feed amendment.