Uncovered Tanks Research Articles

Methane emission rates averaged over a year from ten farm-scale manure storage tanks

Methane (CH4) emissions from animal manure stored in outdoor tanks are difficult to predict because of several influencing factors. In this study, the tracer gas dispersion method (TDM) was used to quantify CH4 emissions from ten manure storage tanks, along with the collection of supporting information, in order to identify its emission drivers. The dataset included two tanks storing dairy cattle manure, six holding pig manure, and two with digestate from manure-based biogas plants. CH4 emissions from the tanks were measured six to 14 times over a year. Emissions varied from 0.02 to 14.30 kg h−1, or when normalised by the volume of manure stored, emission factors (EFs) varied from 0.05 to 11 g m−3 h−1. Annual average CH4 EFs varied greatly between the tanks, ranging from 0.20 to 2.75 g m−3 h−1. Normalised EFs are similar to literature values for cattle and digested manure, but at the high end of the interval for pig manure. The averaged manure temperature for all tanks varied from 10.6 to 16.4 °C, which was higher than reported in a previous Danish study. Volatile solids (VS) concentration was in average higher for cattle manure (ranging from 3.1 and 4.4 %) than pig manure (ranging from 1.0 to 3.6 %). CH4 emission rates were positively correlated with manure temperature, whereas this was not the case for VS concentration. Annual average EFs were higher for pig than for cattle manure (a factor of 2.5), which was greater than digested manure emissions (a factor of 1.2). For the pig manure storage tanks, CH4 emissions were higher for covered tanks than for uncovered tanks (by a factor of 2.3). In this study, manure storage tanks showed a large disparity in emission rates, driven not only by physical factors, but also by farm management practices.

Effect of Rainfall Regime on Rainwater Harvesting Tank Sizing for Greenhouse Irrigation Use

The use of rainwater harvesting tanks to supply human water needs is an old and sustainable practice. In the case of covering irrigation demand in greenhouse agriculture, the potential is huge. Still, the relative research worldwide is low, while it is nearly absent in Greece. In this study, the rainwater harvesting tank size for irrigation use of greenhouse tomato cultivation was investigated by applying a daily water balance model in three regions of Crete Island (Greece) with significant greenhouse areas. Daily rainfall data from three representative rainfall stations of the study areas characterized by different rainfall regime for a 12-year time series were used. Additionally, the daily irrigation water needs for a tomato crop during an 8-month cultivation period were used. The greenhouse roof was defined as catchment area of the rainwater harvesting system and greenhouse areas of 1000, 5000 and 10,000 m2 were studied. In all areas examined, a tank of 30–100 m3 per 1000 m2 of greenhouse area could reach approximately 80–90% reliability. Higher values of reliability (reaching 100%) could be achieved mainly with covered tanks. Tank size for 100% reliability in covered tanks, ranged from 200 m3 (per 1000 m2 of greenhouse area) in the study area with high mean annual rainfall depth (974.24 mm) and moderate mean longest dry period (87.67 days), to 276 m3 (per 1000 m2 of greenhouse area) in the study area with relatively low mean annual rainfall depth (524.12 mm) and high mean longest dry period (117.42 days). For uncovered tanks, a 100% reliability value could be reached only with a tank size of 520 m3 (per 1000 m2 of greenhouse area) in the study area with high mean annual rainfall depth and moderate mean longest dry period.

Reliability Analysis of Rainwater Harvesting Tanks for Irrigation Use in Greenhouse Agriculture

Rainwater harvesting is an ancient water management practice that has been used to cover potable and non-potable water needs. In recent years, this practice is adopted as a promising alternative and sustainable source of water to meet irrigation needs in agriculture in arid and semi-arid regions. In the present study, a daily water balance model was applied to investigate the size of rainwater tanks for irrigation use in greenhouse begonia and tomato cultivation in two regions of Greece with significant greenhouse areas. For the application of the water balance model, daily rainfall depth values of a 12-year time series (2008–2020) from representative rainfall stations of the study areas were used, as well as the daily water needs of the crops. The greenhouse roof was assumed to be the water collection area of the rainwater harvesting system with values ranging from 1000 to 10,000 m2. The analysis of the results showed that in the case of the begonia crop, the covered tanks ranged from 100 to 200 m3 per 1000 m2 greenhouse area with a reliability coefficient that ranged from 65 to 72%, respectively, to meet the water needs of plants. Further increase of the reliability coefficient was carried out with disproportionately large volumes of tanks. In the case of the tomato crop, covered tank volumes ranged from 100 to 290 m3 per 1000 m2 of greenhouse area, and had a reliability coefficient of 90% to 100%, respectively, while uncovered tanks had a maximum reliability coefficient of 91% for a critical tank volume of 177 m3 per 1000 m2 of greenhouse area and decreased for any further increase of tank volume.

A novel approach to estimate the abatement of ammonia emissions from mitigation techniques at farm-scale slurry stores exemplified by a semifloating cover.

Ammonia (NH3 ) losses from livestock slurry stores substantially contribute to agricultural emissions to the atmosphere. Gas release from slurry storage facilities is driven by interactions between store operations and meteorological conditions. This study quantifies the abating effect of an impermeable semifloating cover as an emission mitigation technique at a farm-scale slurry storage tank. Emissions were measured over 1 yr and compared with the preceding 2 yr of measurements with the uncovered tank. In this novel approach, emission data were aggregated to categories within 1 h measuring intervals according to five key factors influencing emissions (time span after agitation and tank-filling level as surrogates for natural crust occurrence; the meteorological parameters precipitation, air temperature, and wind speed) for the two consecutive measurement campaigns with and without the cover. The emission abatement effect of the cover was determined by emission modeling of the entire measuring campaign based on measuring intervals of the uncovered and the covered tank where the aggregated categories of influencing factors were equal. The resulting average emission abatement was 48%. An average abatement of 37 and 54% was achieved during periods with and without a surface crust, respectively. The emission reduction was less with low tank filling level due to higher air exchange through openings of the cover. The presented approach is applicable to evaluate emission mitigation techniques for single farm-scale stores. With adequate measurement duration, it is appropriate to produce reliable emission data reflecting the complex interactions between emissions and influencing factors occurring at real-world storage facilities.

Salmonella in native “village” chickens (Gallus domesticus): prevalence and risk factors from farms in South-Central Peninsular Malaysia

ABSTRACTVillage chicken or Ayam Kampung, common to Southeast Asian countries, has always been regarded as superior in comparison to commercial broiler chicken in terms of wholesomeness and health benefits. The current study investigates the prevalence and risk factors of Salmonella among village chicken flocks from the central and southern states of Peninsular Malaysia. A total of 35 village flocks were sampled from Selangor (n = 19), Melaka (n = 10), Johor (n = 4), and Negeri Sembilan (n = 2). In total, 1,042 samples were collected; these included cloacal swabs (n = 675), eggs (n = 62), pooled drinking water (n = 175), pooled feeds (n = 70), and pooled flies (n = 60). Isolation of Salmonella from cloacal swabs, poultry drinking water, and feeds was carried out according to the protocols and recommendations of the World Organization for Animal Health (OIE) terrestrial manual. The prevalence of Salmonella at an individual bird-level was 2.5% (17/675, 95% CI: 1.6 to 4.0). All eggs screened were negative; in the case of environmental samples, however, Salmonella was detected in 5.14% (9/175), 7.14% (5/70), and 5.0% (3/60) for water, feed, and flies, respectively. A total of 34 isolates and 8 Salmonella serotypes were identified. Weltevreden (20.6%) was the most common, followed by Typhimurium and Agona (17.6%), Albany and Enteritidis (8.8%), Molade (5.9%), Corvallis and Schleissheim (2.9%), and others grouped as Salmonella spp. (11.8%). Multivariable logistic regression models revealed that Salmonella positivity among flocks could be strongly predicted by storage of feeds (uncovered feeds; OR = 10.38; 95% CI: 1.25 to 86.39; p = 0.030) and uncovered water tanks (uncovered tank; OR = 6.43; 95% CI: 1.02 to 40.60; p = 0.048). The presence of Salmonella in village chickens in the study area was lower than that of commercial chickens in Malaysia.

Removal Methods Assessment Through Reduction Algae Count in Uncovered Water Tank

The research includes study the effect of three factors (voltage, rotational speed, acidity) with time to remove or reduce the percentage of algae in uncovered water tank; these factors studied combined with each other or individually. the removal percentage of algae increased by increasing the electrical voltage, Best result of removal was obtained when using two factors, change in the voltage (4, 8,12 and 16) vole /cm and speed of rotation (50, 100, 150 and 200) rpm . The rate of removal of algae was 100% at voltage 16 volts with a rotation speed (200) rpm and 40 min. The values extracted for algae removal showed that the best result was (100%) at (voltage 16 vole/cm and acidity with pH 4) with time 30 min. It can be conclude, the best method to remove or reduction of algae in uncovered tanks was physical one as a compared with the other methods like chemical or biological methods. Therefore, it needs additional requirements unlike physical strategies decrease, the cost and time required to evacuate green growth.

Light conditions and heterogeneity in illumination affect growth and survival of Octopus vulgaris paralarvae reared in the hatchery

In order to succeed in common octopus (Octopus vulgaris) aquaculture, it is necessary to overcome the massive paralarval mortalities, which are likely related to zootechnical and/or nutritional aspects. Among the zootechnical aspects, the effect of light could be vital for the development of paralarvae given their sophisticated visual system. O. vulgaris paralarvae display vertical behavior in the wild, being in deeper waters during the day and close to the surface at night. For this reason, the present study traces a collection of light assays in captivity, to test ecologically-driven hypotheses on the growth and survival of octopus paralarvae.The first assay tested a factorial combination of light colors (blue vs white) and intensity (low ~13 lx (36 W/m2), medium ~87 lx (151 W/m2) and high ~265 lx (422 W/m2)). The results pointed to a significant negative impact of low light intensities (13 and 87 lx) on paralarval growth. The second assay was designed to contrast light colors (blue vs white), different levels of intensities (300 lx (478 W/m2) vs 600 lx (1077 W/m2)) and partial coverage of the tanks using a shade mesh, named as “shadow zone” (half-covered vs non-covered tanks). In half-covered tanks, survival was significantly improved, with the best results coming from half-covered tanks with blue light and 600 lx, but no differences in dry weight were observed. The third experiment tested a factor called “light source position” with two levels: “Control” when the light incidence angle was 0° with respect to the normal direction (i.e. perpendicular to the water surface), and “Oblique” when the light incidence angle was 60° with respect to the normal direction. In this experiment, survival significantly improved under oblique light but no differences in dry weight were detected. The last experiment was an unifactorial design combining “light source position” and “tank partial coverage” with three treatments: i) control light with uncovered tanks, ii) oblique light with uncovered tanks, iii) control light with semi-covered tanks. Oblique light with uncovered tanks was associated with a higher survival rate but without statistical significance, probably due to data variability. It can be concluded that light intensity tended to affect paralarval dry weight, whereas the existence of a shadow zone or oblique light are more related with an improvement of survival rates.

Winterization strategies for bulk storage of cucumber pickles

Cucumbers are commercially fermented and stored in bulk in outdoor open top fiberglass tanks. During winter, snow and ice that accumulates around and on top of tanks influence heat transfer in an unpredictable manner, often compromising quality. This study evaluates the performance of inexpensive and resilient fermentation tank insulation and provides an estimate of heat loss associated with strategies for storage and preservation of fermented cucumbers during winter. Three insulation configurations were explored: conical top-cover, flat top-cover, and perimeter insulation. Changes in temperature during storage were experimentally studied in different tank configurations. A mathematical model was developed to simulate temperature profiles and heat loss in an idealized fermentation/storage vessel. Comparisons of the insulated tank configurations suggested a significant difference in temperature between a flat cover and uncovered tank when exposed to temperatures characteristic of the spring season in Pinconning, MI.

Evaporation reduction from open water tanks using palm-frond covers: Effects of tank shape and coverage pattern

The limited fresh water resources and increasing future demand for water necessitate the importance of optimum use of water; especially in arid/semi-arid regions. The purpose of this study is to examine reducing evaporation losses from open water bodies using palm-frond sheets as cover material. Four open constant-depth water tanks with two different surface areas have been used in the study. The tanks had square and rectangular surface areas. The tanks were covered with two patterns of palm-frond sheets: a) staggered strips-no strips covering half of the surface area (strips-covered), and b) single sheet covering half of the surface area (½-covered). Data of cumulative evaporation depths were recorded daily continuously from the covered tanks, as well as from the uncovered tanks, to assess the relative efficiency of evaporation reduction. The results indicated that the strips-covered pattern outperformed the ½-covered; it reduced the evaporation depth by approximately 20% and 24% for the square and rectangular surface tanks; respectively, when compared to the ½-covered pattern. Moreover, the strips-covered pattern resulted in approximately 76% less evaporation depth compared to the uncovered reference tanks. Additionally, water quality analyses showed that such palm-based cover materials have insignificant effect on the water quality. These results confirmed that evaporation can be reduced and controlled using environment friendly safe techniques.

Use of Bottom Structure and Tank Cover during Rainbow Trout Rearing in Circular Tanks

The use of environmental enrichment has been found to be beneficial in fish rearing performance and behavior. This study evaluated the effects of partial overhead cover and rearing tank substrate on the hatchery performance of juvenile rainbow trout Oncorhynchus mykiss. Four treatments were used in circular tanks: open tanks with concrete blocks, partially-covered tanks with blocks, open tanks with no concrete blocks, and partially-covered tanks with no blocks. There was no significant effect of concrete block substrate use on rainbow trout weight gain or feed conversion ratio. However, fish reared with overhead cover had a significant weight gain increase and a significant feed conversion ratio decrease compared to uncovered tanks. There was no significant interaction between cover and substrate. The use of overhead cover is recommended to increase trout rearing performance in circular tanks.

A Note on Distribution of Breeding Sources of Aedes aegypti (Linnaeus) in the City of Kolkata, India, Following an Outbreak of Dengue during 2012

An Aedes aegypti (larval) survey was conducted by the vector control department of Kolkata Municipal Corporation (KMC), following an outbreak of dengue in Kolkata City in July 2012. Results obtained are startling. Small discarded items were the major breeding sources of Ae. aegypti (prime vector of dengue). Outdoor containers such as battery shells at market places, old tyres at garages and tyre-retreading centres and wells at construction sites represented the first, second and third categories of preferred breeding sites of this vector mosquito. In the past, Ae. aegypti in Kolkata City was quite photophobic with regard to its breeding habit; it used to breed more indoors—mostly in small uncovered masonry tanks used for water storage indoors. But the very mosquito now breeds more outdoors; it has become photophilic. Ecological compulsion created by the people of Kolkata through periodic emptying and cleaning of their masonry tanks and other indoor water storage containers following the KMC’s intensive mass awareness campaigns over the past several years, seemed to have compelled Ae. aegypti to shift its breeding sites from indoors to outdoors for its better survival in the city’s environment. The need for active involvement of some other departments of KMC—besides the health department—such as the departments of solid waste management, building, water supply and drainage, too, was clearly pointed out by the study. Accordingly, multipronged strategies—including prompt destruction of the breeding sources of Ae. aegypti right from the month of January by involving all the concerned departments—were planned and religiously implemented by KMC during 2013. The concerted efforts yielded commendable results: the number of dengue cases downslided from a staggering 1852 (with 2 deaths) in 2012 to a comfortable 238 (with no death) in 2013.

A floating coverage system for digestate liquid fraction storage

Anaerobic digestion is booming in the nations of Europe. In fact, Italy alone has approximately 500 plants in operation or in some phase of start-up. Previous studies have made evident the potential that lies in digested manure residual biogas. Nevertheless, much of the potential goes unrealized when enormous amounts of digestate are produced, but are then stored in uncovered tanks. This research work designed, constructed, and tested a low-cost digestate storage tank cover system capable of abating CO2eq atmospheric emissions and then recovering the biogas. The experiment, carried out at a 1MW electric anaerobic digestion plant, demonstrated that collecting the residual biogas from the digested liquid fraction storage tank made it possible to avoid atmospheric emissions of up to 1260t CO2eq annually and to increase the methane yield of the installation by 3%.

Residual biogas potential from the storage tanks of non-separated digestate and digested liquid fraction

Biogas plants daily produce enormous volumes of digestate that can be handled in its raw form or after mechanical separation. In Italy, effluents are usually stored within aboveground, uncovered tanks, which make them potential emitters of biogas into the atmosphere. The purpose of this study was to estimate the amount of biogas emitted to the atmosphere during the storage phase of non-separated digestate and digested liquid fraction. The trials were performed at two northwest Italy 1MWel. biogas plants. A floating system for the residual biogas recovery, and a set of three wind tunnels for NH3 emission measurement were used. The experiment demonstrated significant loss to the atmosphere for each of the gases; specifically, on average, 19.5 and 7.90Nm3biogasMWhel.−1 were emitted daily from the storage tanks of non-separated digestate and digested liquid fraction, respectively.

The methane yield of digestate: Effect of organic loading rate, hydraulic retention time, and plant feeding

In biogas plants, huge volumes of digestate are produced daily and stored in uncovered tanks, which leak methane into the atmosphere and cause negative environmental impacts. To better understand the effect that different operating parameters of anaerobic digestion plants have on digestate residual methane yield, four digestate samples collected from plants with very different operations were analysed in batch reactors. Their methane yields were very heterogeneous and varied between 2.88 and 37.63 NL/kgVS. The methane yield was shown to be highly influenced by the A.D. plant Organic Loading Rate and by feedstock quality; hydraulic retention time had only limited effects.

Partial Overhead Tank Cover Use during Feral Brown Trout Rearing

AbstractOverhead cover is an essential component of the habitat of wild brown trout Salmo trutta but is typically lacking during hatchery rearing. To evaluate the effect of cover during hatchery rearing, we grew feral brown trout in circular tanks that were either completely open on top or partially (29%) covered. After 51 d of rearing in 2001, the total biomass of fish per tank was significantly greater in the partially covered tanks than in the completely open tanks. Feed conversion was also significantly reduced by the use of partial tank covers (1.13 versus 1.29 in the open tanks). After 45 d of rearing in 2003, the mean total weight gain of fish per tank was 13.8 kg in tanks with partial covers and 12.9 kg in uncovered tanks, and feed conversion was 0.79 for partially covered tanks and 0.85 for uncovered tanks. In addition, fish reared in tanks with partial covers were significantly longer and heavier (56.3 mm, 1.62 g) than fish reared in open tanks (54.1 mm, 1.42 g), although there was no significant difference between the open or partially covered tanks in total tank weight gain or conversion in 2003. No significant differences in percent mortality were observed between groups reared in partially covered and uncovered tanks. The use of partial tank covers can increase the growth of feral juvenile brown trout in circular tanks during hatchery rearing.

Arsenic Ingestion and Bladder Cancer Mortality—What Do the Dose-Response Relationships Suggest About Mechanism?

ABSTRACT The Black–Foot Disease (BFD) endemic area of SW Taiwan has historically been the principal data source for assessing cancer risks from arsenic in drinking water in the United States, most recently in a 42–village ecological study. The data showed a discontinuity for bladder cancer risk at about 400 μg/L. A proposed explanation was that the arsenic–dependent bladder cancer risk was found only for those villages that were dependent on water from the artesian well aquifer (As > 350 μg/L and co–contamination with humic acids) and not for those villages receiving water from the shallow aquifer (As < 350 μg/L without humic acids). The humic acids were present from the algae that grew in the uncovered tanks holding the artesian water. The risk factors (slopes) developed from these subpopulations of the SW Taiwan study were applied to the data from an ecological study of median groundwater arsenic concentration and bladder cancer mortality in 133 U.S. counties dependent on groundwater to determine the slope most predictive of U.S. experience for bladder cancer mortality and arsenic ingestion (Lamm et al. 2004).The U.S. data excluded the SW Taiwan slope estimate derived from the artesian well–dependent subpopulation but were consistent with the slope estimate derived from the subpopulation using shallow aquifer water. Both the SW Taiwan data in the absence of high arsenic levels (< 350 μg/L) and humic acids and the U.S. 133–county data with As < 60 μg/L are consistent with no increased bladder cancer mortality risk from drinking water arsenic concentrations in the exposure range of observation. These analytic results are consistent with both co–carcinogenesis and high–exposure (hundreds of μ g/L As) dependence models of toxicological mode–of–action. These dose–response relationships should influence prioritization in the remediation of arsenic–contaminated drinking water supplies.

The influence of body size, habitat and diet concentration on feeding of Laternula marilina Reeve

A Chinese duckbilled marine clam (Laternula marilina Reeve) was cultured in a simulated natural culture system for the preliminary determination of its physiological energetics. The results showed that both clearance rate (CR) and ingestion rate (IR) were related exponentially to body size (flesh dry weight, W) as described by the equations CR=0.49W0.65, IR=0.96W0.57. Body size had no effect on assimilation efficiency (AE) at water temperatures of 10°C, 16°C and 23°C, but within this range AE significantly increased with increasing water temperature. It was found that L. marilina performed in feeding behaviour far better when natural substrates conditions were provided. On a sand or silt substrate both CR and IR were two times higher than on an uncovered tank bottom. AE was also improved when sand (13.12% increase) or silt (14.19% increase) was provided. It is evident in our results that within the range of diet (as particulate organic matter, POM) concentration of 2.30±0.21 to 6.20±0.13 mg POM L−1 the relationships between POM and CR and IR were exponential and as described by the equations CR=0.29 [POM]0.75, IR=0.33 [POM]1.34. In these experiments, the diet concentration threshold of pseudofaecal excretion was found to be 3.05 mg POM L−1. There was no marked influence of diet concentration on AE, which was consistently about 60%.

Effects of Partial Tank Covers on the Growth of Juvenile Feral Rainbow Trout during Hatchery Rearing

AbstractPartial tank covers were evaluated for their effects on the growth of juvenile feral McConaughy strain rainbow trout Oncorhynchus mykiss during hatchery rearing. Trout were reared in 1999 and 2000 in circular tanks that were either completely open on top or partially (29%) covered. Trout reared in tanks with partial covers were 93 mm long at the end of 55 d of rearing in 1999, which was significantly longer than the 88‐mm mean length of trout reared in uncovered tanks. Total lengths were also significantly different after 34 d of rearing in 2000: 81 mm for fish from partially covered tanks and 78 mm for fish from open tanks. The total weight gains of fish per tank were significantly greater (23.9 versus 22.7 kg) and feed conversions were significantly better (0.83 versus 0.87) in partially covered tanks in 1999. In 2000, the total weight gain of fish per tank was 15.4 kg in tanks with partial covers and 13.5 kg in uncovered tanks, and the respective feed conversions were 0.90 and 1.05. However, neither weight gain nor conversion was significantly different in 2000. No significant differences in percent mortality were observed in fish reared with or without partial covers.

Ammonia volatilization during storage of cattle and pig slurry: effect of surface cover

SUMMARYGaseous NH3 losses from pig and cattle slurry stored in eight storage tanks were measured simultaneously using wind-tunnels. The slurry was either stirred weekly (uncovered), or was allowed to develop a natural surface crust. Oil, peat, chopped cereal straw, PVC foil, leca® (pebbles of burned montmorillonitic clay) and a lid were tested as additional covers. Convective transport of ammonium to the surface layers caused NH3 volatilization losses of 3–5 g NH3-N/m2 per day from the stirred, uncovered tanks. The loss of NH3 from the stirred slurry was related to air temperature. The development of a natural surface crust reduced NH3 losses to 20% of those from stirred slurry. NH3 losses from slurry not developing a natural surface crust layer and left undisturbed were similar to the losses from stirred slurry. A 15 cm layer of straw was as effective as a surface crust layer in reducing NH3 losses. In one experiment, cracks developed in the oil cover and losses were therefore only reduced to 50% of those of uncovered slurry. Apart from this experiment, NH3 losses from slurry covered with oil, leca®, peat and foil were small.