Jactone Arogo Ogejo

Occurrence, fate and removal of synthetic oral contraceptives (SOCs) in the natural environment: a review.

Synthetic oral contraceptives (SOCs) are a group of compounds with progestagenic and/or androgenic activities, with some also possessing estrogenic activities. Recent research has documented that some of these emerging contaminants have adverse effects on aquatic organisms at very low concentrations. To facilitate the evaluation of their latent risks, published works on their occurrence and fate in the environment are reviewed. Androgenic/progestagenic relative potencies or relative binding affinity of these SOCs as well as their physicochemical properties and toxicity are summarized. Appropriate analytical methods are outlined for various environmental sample types, including methods of sample preparation and limit of detection/quantification (LOD/LOQ). Finally results on their occurrence and fate in wastewater treatment plants (WWTPs) and other environments are critically examined.

Effects of reducing dietary nitrogen on ammonia emissions from manure on the floor of a naturally ventilated free stall dairy barn at low (0-20°C) temperatures.

This study was conducted to determine the potential for reducing ammonia (NH3) emissions from manure deposited on the floor of a naturally ventilated free stall barn by mid-lactation dairy cows fed reduced or normal N diets. Two crude protein (CP) diets (178 g kg(-1) [high] and 159 g kg(-1) [low] dry matter ), were used. The diets were fed to 48 Holstein cows in a replicated crossover design with two pens per diet. The NH3 emitted from the manure deposited on the floor was measured using a dynamic flux chamber. The NH3 emissions were 2.7 (+/-2.0) and 2.9 (+/-1.8) g N cow(-1) d(-1) for high and low CP diets, respectively. Ammonia emission rates were significantly affected by manure pH, TKN, and ambient air temperature (P<0.05). Dietary CP affected the feed N intake (8.7 and 7.1 kg pen(-1) d(-1) for high and low CP, respectively), but did not affect milk yield (500 and 489 kg pen(-1) d(-1) for high and low CP, respectively) and milk CP content (30 g kg(-1) for both the high and low CP diets). The N utilization efficiency was 29.0% and 32.7% for the high and low CP diets, respectively. Reducing dietary CP reduced total Kjeldahl N (TKN) in manure, but did not affect the total ammoniacal N (TAN) in manure and had no significant effect on the ammonia emission rates from the barn floor.

Prefermentation of liquid dairy manure to support biological nutrient removal.

A continuously operated, intermittently fed reactor (fermenter) system with a 2-d solids retention time was proposed for supporting biological nutrient removal from liquid dairy manure. The first objective of this study was to select a material with high fermentation potential to be used as the fermenter feed. Primary sludge, liquid separated dairy manure, and flushed dairy manure were investigated for their fermentation potential. Liquid separated dairy manure had the highest fermentation potential, 0.73mg volatile fatty acid as chemical oxygen demand/mg of initial volatile suspended solids (VSS). The second objective was to investigate the performance of a pilot-scale fermenter operated under an average organic loading rate (OLR) of 3 kg-VSS/m(3)/d. The reactor utilized 18% of the manure fermentation potential. Performance comparison of the pilot-scale fermenter and a lab-scale fermenter with an average OLR of 7 kg-VSS/m(3)/d highlighted the need to increase the OLR of the pilot-scale fermenter so that it can exploit a higher fraction of the manure fermentation potential. A continuously operated, intermittently fed fermenter with 2-d SRT can utilize the majority of the manure fermentation potential and support a downstream BNR reactor provided that it receives a sufficiently high OLR.

Enhanced Biological Phosphorus Removal for Liquid Dairy Manure

The objective of this study was to evaluate the efficiency of P removal from separated liquid dairy manure by a research scale (16 L) EBPR system. EBPR was successful, as demonstrated by up to 98% reduction of the dissolved reactive phosphorus (DRP) when the manure was diluted 1:5 with tap water. When the dilution was reduced to 1:4, the DRP reduction efficiency dropped to 70%. Successful EBPR was demonstrated with dairy manure, but efficiency was affected by dilution. Additional work is needed to reduce the amount of fresh water addition required and to thicken the high P sludge.

Ammonia Emissions from Dairy Manure Storage Tanks

Reducing dietary nitrogen (N) has been reported as a possible solution to reduce ammonia emissions from dairy manure. This paper reports a year-long study on ammonia emissions from dairy manure storage tanks. The effects of cow diet (Control vs. Low-N) and manure management (scraping vs. flushing) are determined. The Low-N diet (15% Crude Protein) reduced daily ammonia loss from manure storage tanks by 17.7% for scraped manure and by 2.6% for flushed manure, compared to the Control diet (18% Crude Protein). In addition, daily ammonia loss from flushed manure was 28% lower than that of scraped manure in the first 9 weeks, which demonstrated that dilution with water reduces ammonia emissions. Ammonia emissions were affected by temperature and other environmental conditions over diurnal to seasonal time scales. Generally ammonia emissions increased as temperature increased and decreased during rainfall or snow events. The emerging results show that average daily ammonia emissions in winter are lower than that in fall. The study is still in progress.

Adjusting nitrogen to phosphorus ratios in liquid dairy manure through nitrification and chemical phosphorus removal to match crop fertilizer requirements

The objectives of this study are to (1) develop a cost effective treatment strategy to conserve nitrogen (N) in liquid dairy manure by determining the minimum aeration to non-aeration ratios required to conserve N in the manure, and (2) evaluate the suitability of using chemicals to reduce phosphorus (P) concentrations in liquid dairy manure treated as in objective (1) to achieve suitable N:P ratios for crop production.

Multiple Applications of Sodium Bisulfate to Broiler Litter Affect Ammonia Release and Litter Properties.

Ammonia (NH) emissions from animal manures can cause air and water quality problems. Poultry litter treatment (PLT, sodium bisulfate; Jones-Hamilton Co.) is an acidic amendment that is applied to litter in poultry houses to decrease NH emissions, but currently it can only be applied once before birds are placed in the houses. This project analyzed the effect of multiple PLT applications on litter properties and NH release. Volatility chambers were used to compare multiple, single, and no application of PLT to poultry litter, all with and without fresh manure applications. A field component consisted of two commercial broiler houses: one had a single, preflock PLT application, while the other received PLT reapplications during the flock using an overhead application system. In the volatility chambers, single and reapplied PLT caused greater litter moisture and lower litter pH and , relative to no PLT. After 14 d, NH released from litter treated with reapplied PLT was significantly less than litter with both single and no applications. Furthermore, total N in litter was greatest in litter treated with reapplied PLT, increasing its fertilizer value. In the commercial poultry houses, PLT reapplication led to a temporary decrease in litter pH and , but these effects did not last because of continued bird excretion. Although one preflock PLT application is currently used as a successful strategy to control NH during early flock growth, repeat PLT application using the overhead reapplication system was not successful because of problems with the reapplication system and litter moisture concerns.

Evaluation of an On-Farm Two Stage Anaerobic Digester for Biogas/Biomethane production from Dairy Manure

Anaerobic digestion of dairy manure has the benefits of reducing greenhouse gas emissions, odors, and waste strength while producing biomethane (CH4). This study presents the first year performance data of an on-farm anaerobic digester (AD) on 1200 milking herd dairy farm in Virginia. The AD was designed as a two- stage reactor system operated at mesophilic conditions (38°C) with a volumetric manure flow rate of approximately 125 m3/d. The AD performance was evaluated with respect waste stabilization and biogas production. Samples of the digester influent, effluent, and separated liquid were collected at least once a month and analyzed for manure characteristics including pH, solids, chemical oxygen demand (COD), volatile fatty acids, and nutrient content. Biogas quantity and quality were also routinely monitored. Average concentrations of total and soluble COD decreased by 32 and 55%, respectively, between the digester influent and effluent. Average total volatile fatty acid concentrations were reduced by 91.2%. The total and volatile solids reductions were 30 and 35%, respectively. Average daily biogas production was 5,636 m3 (standard cubic meters) with an average methane concentration of 54%. Biogas was converted to electricity by an on-farm generator which on average produced 360 KWH of electricity per day. The electricity produced was fed to the local grid. Excess biogas was flared or used in a boiler when engine is not running.

Chemical Phosphorus Removal for Separated Flushed Dairy Manure

The objective of this study was to determine effective and economical dosages of chemicals to remove phosphorus (P) from liquid dairy manure, the chemical and polymer dosages to treat manure in a full-scale case study at the Virginia Tech dairy, and the cost of manure treatment and land application of P-rich sludge produced. Ferric chloride (FeCl3·6H2O), ferric sulfate (Fe2[SO4]3·5H2O), aluminum chloride (AlCl3·6H2O), aluminum sulfate (Al2[SO4]3·13H2O, alum), and five cationic polyacrylamides were evaluated at varying dosages using jar tests on liquid manure with 0.87% and 1.5% total solids (TS) concentration. Treated manure was settled in Imhoff cones to determine the sludge volume; supernatant of the settled treated manure was analyzed for total P, solids, and pH. Based on the P removal efficiency of the preliminary jar tests, ferric chloride, alum, and Superfloc 4512 (an ultra-high molecular weight polyacrylamide) were selected for further testing. Polymer addition enhanced floc size and settleability of sludge and improved P removal. Jar tests using combinations of chemical and polymer provided more than 97% P removal from liquid dairy manure obtained from one storage tanks showing the potential for high P removal. A subsequent batch test on a field scale manure storage tank containing 1,860 m3 of manure with 1.2% TS and 157 mg P/L was conducted using 200 mg/L AlCl3 as Al and 100 mg/L of Superfloc 4512 polymer. Approximately 84% of the total P was sequestered in a P-rich sludge. A portion of the sludge (600 m3) was transported off the farm for land application. The total cost of treating manure and transporting the P rich sludge was

Contribution of 17-ß estradiol to total estrogenicity in dairy manure subject to anaerobic digestion or separation and aeration

4.09/m3 (