planBMP {biogas}

Claculate Inoculum and Substrate Mass for BMP Experiments

Description

planBMP assists in the design of BMP experiments. It can be used to determine inoculum and substrate masses based on inoculum-to-substrate ratio and volatile solids concentrations, or to calculate inoculum-to-substrate ratio based on masses.

Usage

planBMP(vs.inoc, vs.sub, isr = NA, m.inoc = NA, m.sub = NA, 
        m.tot = NA, m.vs.sub = vs.sub * m.sub, digits = 3, warn = TRUE,
        nice = TRUE)

Arguments

vs.inoc

volatile solids (VS) concentration of inoculum (g/g = g VS per g inoculum). Required. Numeric vector.

vs.sub

volatile solids (VS) concentration of substrate (g/g = g VS per g substrate). Required. Numeric vector.

isr

inoculum-to-substrate ratio, VS mass basis. Optional. Numeric vector.

m.inoc

total mass of inoculum (g). Optional. Numeric vector.

m.sub

total mass of substrate (g). Optional. Numeric vector.

m.tot

total mass of mixture (inoculum plus substrate) (g). Optional. Numeric vector.

m.vs.sub

VS mass of substrate (g). Optional. Numeric vector.

digits

number of significant digits to display in output. Default of 3. Integer vector with length 1.

warn

control whether warnings are displayed. Default of TRUE. Logical vector with length 1.

nice

control whether output is formatted to look nice and make reading easier. Default of TRUE. Only applied for non-vectorized (length 1) calls. Logical vector with length 1.

Details

BMP experiments should be designed giving consideration to the inoculum-to-substrate ratio (ISR), the substrate VS mass, and the mixture VS concentration. This function calculates inoculum and substrate masses based on VS concentrations and ISR, along with either total mixture mass or substrate VS mass. Alternatively, it can be used to calculate ISR if the masses have been selected. Warnings are based on the guidelines of Holliger et al. (2016).

Value

A named numeric vector, or (if any of the first 7 input arguments have a length > 1, i.e., a vectorized call), a data frame. Names and interpretation are identical to the first 7 input arguments, and also include:

vs.mix

VS concentration in mixture (g/g)

m.vs.tot

total VS mass in mixture (g)

For non-vectorized calls, the results is returned invisibly and a easy-to-read summary is printed (see nice argument).

Note

Calculations used in this function are trivial, and they could also be done with a spreadsheet or even pencil and paper. The advantage here is ease and some flexibility. In addition to ISR and the other parameters included in this function, expected biogas production rate and bottle headspace volume are important, depending on the method. For more details, see Holliger et al. (2016).

Author(s)

Sasha D. Hafner, based on suggestion by Konrad Koch

References

Holliger, C., Alves, M., Andrade, D., Angelidaki, I., Astals, S., Baier, U., Bougrier, C., Buffiere, P., Carbella, M., de Wilde, V., Ebertseder, F., Fernandez, B., Ficara, E., Fotidis, I., Frigon, J.-C., Fruteau de Laclos, H., S. M. Ghasimi, D., Hack, G., Hartel, M., Heerenklage, J., Sarvari Horvath, I., Jenicek, P., Koch, K., Krautwald, J., Lizasoain, J., Liu, J., Mosberger, L., Nistor, M., Oechsner, H., Oliveira, J.V., Paterson, M., Pauss, A., Pommier, S., Porqueddu, I., Raposo, F., Ribeiro, T., Rusch Pfund, F., Stromberg, S., Torrijos, M., van Eekert, M., van Lier, J., Wedwitschka, H., Wierinck, I., 2016. Towards a standardization of biomethane potential tests. Water Science and Technology 74, 2515-2522.

See Also

calcBgVol, calcBgMan, calcBgGD, cumBg, summBg, predBg

Examples

  # Bottles are 500 mL, substrate is wastewater sludge.
  # Assume we want no more than 250 mL reacting volume (~250 g)
  # First try setting ISR and total mass.
  # VS concentrations: 0.02 g/g in inoculum, 0.07 g/g for substrate, ISR = 2.
  planBMP(vs.inoc = 0.02, vs.sub = 0.07, isr = 2, m.tot = 250)
  # Get 31 g substrate, 220 g inoculum.
  
  # After setup, we can check final values.
  planBMP(vs.inoc = 0.018, vs.sub = 0.072, m.sub = 32, m.inoc = 218)
  # We didn't quite meet our target in this case--next time use more inoculum to be sure
  
  # We can alternatively specify substrate VS mass
  planBMP(vs.inoc = 0.02, vs.sub = 0.07, isr = 2, m.vs.sub = 2)
  
  # Some options
  planBMP(vs.inoc = 0.02, vs.sub = 0.07, isr = 2, m.vs.sub = 2, nice = FALSE)
  # Perhaps we want to use three different ISRs
  planBMP(vs.inoc = 0.02, vs.sub = 0.07, isr = 2:4, m.vs.sub = 2, nice = FALSE)