Injection of nutrients

Schmidt CAB, Barbosa MC, de Almeida MDSS. (2007). A laboratory feasibility study on electrokinetic injection of nutrients on an organic, tropical, clayey soil. Journal of Hazardous Materials 143 655-661. 

Thevanayagam S, Rishindran T. (1998). Injection of nutrients and TEAs in clayey soils using electrokinetics. Journal of Geotechnical and Geoenvironmental Engineering 124 330-338. 

The study by Walker (1967) in which the yolk of 4-day chick embryos was replaced by various yolk fractions provided an interesting comparison to the above observations and represented the only additional study dealing with the direct effect of yolk fractions on the early embryo. In these studies the yolk was removed after 3 days of incubation by the method of yolk-sac perfusion and replaced on the fourth day with a single injection of nutrients. After 4 additional days of incubation embryos were weighed, their extraembryonic membranes were examined, and survival was recorded. A comparison of the three fractions analyzed in this study with yolk at equal levels of nitrogen indicated that embryo growth on supernatant plasma and the floating fractions was comparable... 

Microbial-enhanced oil recovery involves injection of carefully chosen microbes. Subsequent injection of a nutrient is sometimes employed to promote bacterial growth. Molasses is the nutrient of choice owing to its low (ca 100/t) cost. The main nutrient source for the microbes is often the cmde oil in the reservoir. A rapidly growing microbe population can reduce the permeabiHty of thief zones improving volumetric sweep efficiency. Microbes, particularly species of Clostridium and Bacillus, have also been used to produce surfactants, alcohols, solvents, and gases in situ (270). These chemicals improve waterflood oil displacement efficiency (see also Bioremediation (Supplement)). 

Aeration of the hypolimnion (lower, colder layer of water in a stratified lake) without disruption of stratification has been used in deep lakes. This has the advantage of not increasing the temperature of the hypolimnion and prevents the advection of nutrient-rich water into the epilimnion (upper, warmer layer of water in a stratified lake). Oxygen injection is preferred in order to prevent the build up of nitrogen super-saturation which is toxic to fish. "... 

Injection of acidic, nutrient-rich water into the highly alkaline soils resulted in "cementing" of the soils. 

Another important factor is the food/nutrient ratio. Many of the necessary nutrients may already be present in the aquifer, such as K, Mg, Ca, S, Na, Mn, Fe, and trace elements however, N and P may be deficient and need to be added. The optimum ratio of BOD N P is 100 5 1. It is not a good practice to inject a large quantity of nutrients in the aquifer at one go. They should be fed at the required usage rate throughout the cleanup process. Both the organic contaminants and the nutrients should be completely exhausted by the end of the in situ remediation of an aquifer. 

The in situ bioremediation application at this site included injection of a liquid microbial solution into the subsurface through monitoring and injection wells. This solution includes microbes (Pseudomonas, Bacillus, and Corynebacterium), oxygen, emulsifier, surfactant, and nutrients. Five injections were conducted. Over 11.3 m3 (3000 gallons) was injected from February 1999 to September 2000 into approximately 40 wells and 15 Geoprobe injection points. As of September 2000, MTBE levels decreased by 96% (3310-146 pg/L), while benzene decreased by 83% (2571— 435 pg/L), toluene by 66% (24,330-8300 pg/L), and naphthalene by 84% (5377-853 pg/L) xylene levels increased and were above preoperational level as of September 2000. The system will continue to be operated until all target levels have been met. The total cost for the cleanup of this site is USD63,500.34... 

We also investigated several cost reduction exercies, such as, a) giving the starved bacteria short bursts of nutrient (less than 50 pore volumes) instead of a continuous flow and b) injecting fewer starved bacteria into the core (150 pore volumes) before nutrient injection. Both still resulted in deep bacterial plugs when SCM was used as a nutrient. 

Good transport of nutrient to cells and products from cells Can be easily modified with cell adhesion ligands Can be injected in vivo as a liquid that gets at body temperature Usually biocompatible Disadvantages Can be hard to handle... 

Flow injection analysis is a rapid method of automated chemical analysis that allows for quasi-continuous recording of nutrient concentrations in a flowing stream of seawater. The apparatus used for flow injection analysis is generally less expensive and more rugged than that used in segmented continuous flow analysis. A modified flow injection analysis procedure, called reverse flow injection analysis, was adopted by Thompson et al. [213] and has been adapted for the analysis of dissolved silicate in seawater. The reagent is injected into the sample stream in reverse flow injection analysis, rather than vice versa as in flow injection analysis. This results in an increase in sensitivity. 

Microbial response to injection of electron acceptors and nutrients may be conducted. 

In its basic form, bioremediation of the vadose zone involves introduction of nutrients and electron acceptors necessary to stimulate the indigenous bacteria and provide for removal of waste products generated by the reactions. This sometimes takes the form of a series of injections of a soup of nutrients and electron acceptors into the vadose zone through wells, or infiltration galleries. Other sites may require pressure fracturing of the soil before the stimulant blend can be injected. 

Enhanced biorestoration is thus the process of providing all the materials necessary for optimum degradation of the contaminant of concern. This process can include direct injection of air or nutrients, circulation of groundwater to distribute materials, addition of cometabolites (such as sugar) where additional sources of carbon and attached oxygen are needed, or injection of special inhibitors to limit precipitation of pore-plugging iron oxides. 

Soil injection of farm slurries and sewage sludges eliminates the odour and visual problem associated with surface spreading, it can control surface run-off and help prevent watercourse pollution. It can avoid crop taint and pathogen transfer on pastures and can provide soil loosening with better nutrient management. 

Quantitative measurement of diffusional uptake and carrier-mediated transport of nutrients and drugs in experimental animals was greatly facilitated with the introduction of Olden dorfs brain uptake index (BUI) [42].Test and reference tracers are injected as an intraarterial bolus into the carotid artery of the anaesthetized animal. After 5 s the animal is killed and the brain is removed for radioactivity counting. This method measures the ratio of the unidirectional brain extraction, E, of the test substance and of the reference ([ H]-water, [ " C]-butanol), which are labelled with different isotopes, during a single passage through the brain capillary bed ... 

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