dewatering_bsm2 ¶

Dewatering ¶

Dewatering(dw_par)

Calculates the water and sludge stream concentrations from an 'ideal' dewatering unit based on a fixed percentage of solids in the dewatered sludge.

A defined amount of total solids are removed from the influent sludge stream and goes into the stream of dewatered sludge and the remaining will leave with the reject water phase. Soluble concentrations are not affected.
Temperature is also handled ideally, i.e. T(out)=T(in).

Parameters:

Name	Type	Description	Default
`dw_par`	`ndarray(7)`	Dewatering parameters. [dewater_perc, TSS_removal_perc, X_I2TSS, X_S2TSS, X_BH2TSS, X_BA2TSS, X_P2TSS]	required

Source code in src/bsm2_python/bsm2/dewatering_bsm2.py

def __init__(self, dw_par):
    self.dw_par = dw_par

output ¶

output(ydw_in)

Returns the sludge and reject concentrations from an 'ideal' dewatering unit.

Parameters:

Name	Type	Description	Default
`ydw_in`	`ndarray(21)`	Dewatering influent concentrations of the 21 components (13 ASM1 components, TSS, Q, T and 5 dummy states). [SI, SS, XI, XS, XBH, XBA, XP, SO, SNO, SNH, SND, XND, SALK, TSS, Q, TEMP, SD1, SD2, SD3, XD4, XD5]	required

Returns:

Name	Type	Description
`ydw_s`	`ndarray(21)`	Waste sludge (underflow) concentrations of the 21 components (13 ASM1 components, TSS, Q, T and 5 dummy states). [SI, SS, XI, XS, XBH, XBA, XP, SO, SNO, SNH, SND, XND, SALK, TSS, Q, TEMP, SD1, SD2, SD3, XD4, XD5]
`ydw_r`	`ndarray(21)`	Reject water (overflow) concentrations of the 21 components (13 ASM1 components, TSS, Q, T and 5 dummy states). [SI, SS, XI, XS, XBH, XBA, XP, SO, SNO, SNH, SND, XND, SALK, TSS, Q, TEMP, SD1, SD2, SD3, XD4, XD5]

Source code in src/bsm2_python/bsm2/dewatering_bsm2.py

def output(self, ydw_in):
    """Returns the sludge and reject concentrations from an 'ideal' dewatering unit.

    Parameters
    ----------
    ydw_in : np.ndarray(21)
        Dewatering influent concentrations of the 21 components
        (13 ASM1 components, TSS, Q, T and 5 dummy states). \n
        [SI, SS, XI, XS, XBH, XBA, XP, SO, SNO, SNH, SND, XND, SALK, TSS, Q, TEMP,
        SD1, SD2, SD3, XD4, XD5]

    Returns
    -------
    ydw_s : np.ndarray(21)
        Waste sludge (underflow) concentrations of the 21 components
        (13 ASM1 components, TSS, Q, T and 5 dummy states). \n
        [SI, SS, XI, XS, XBH, XBA, XP, SO, SNO, SNH, SND, XND, SALK, TSS, Q, TEMP,
        SD1, SD2, SD3, XD4, XD5]
    ydw_r : np.ndarray(21)
        Reject water (overflow) concentrations of the 21 components
        (13 ASM1 components, TSS, Q, T and 5 dummy states). \n
        [SI, SS, XI, XS, XBH, XBA, XP, SO, SNO, SNH, SND, XND, SALK, TSS, Q, TEMP,
        SD1, SD2, SD3, XD4, XD5]
    """

    # dewater_perc, TSS_removal_perc, X_I2TSS, X_S2TSS, X_BH2TSS, X_BA2TSS, X_P2TSS = dw_par
    # y = ydw_s, ydw_r
    # u = ydw_in

    ydw_s = np.zeros(21)
    ydw_r = np.zeros(21)

    tssin = (
        self.dw_par[2] * ydw_in[XI]
        + self.dw_par[3] * ydw_in[XS]
        + self.dw_par[4] * ydw_in[XBH]
        + self.dw_par[5] * ydw_in[XBA]
        + self.dw_par[6] * ydw_in[XP]
    )

    dewater_factor = self.dw_par[0] * 10000 / tssin
    qu_factor = self.dw_par[1] / (100 * dewater_factor)
    reject_factor = (1 - self.dw_par[1] / 100) / (1 - qu_factor)

    if dewater_factor > 1:
        # sludge
        ydw_s[:] = ydw_in[:]
        ydw_s[XI] = ydw_in[XI] * dewater_factor
        ydw_s[XS] = ydw_in[XS] * dewater_factor
        ydw_s[XBH] = ydw_in[XBH] * dewater_factor
        ydw_s[XBA] = ydw_in[XBA] * dewater_factor
        ydw_s[XP] = ydw_in[XP] * dewater_factor
        ydw_s[XND] = ydw_in[XND] * dewater_factor
        ydw_s[TSS] = tssin * dewater_factor
        ydw_s[Q] = ydw_in[Q] * qu_factor
        ydw_s[XD4] = ydw_in[XD4] * dewater_factor
        ydw_s[XD5] = ydw_in[XD5] * dewater_factor

        # reject
        ydw_r[:] = ydw_in[:]
        ydw_r[XI] = ydw_in[XI] * reject_factor
        ydw_r[XS] = ydw_in[XS] * reject_factor
        ydw_r[XBH] = ydw_in[XBH] * reject_factor
        ydw_r[XBA] = ydw_in[XBA] * reject_factor
        ydw_r[XP] = ydw_in[XP] * reject_factor
        ydw_r[XND] = ydw_in[XND] * reject_factor
        ydw_r[TSS] = tssin * reject_factor
        ydw_r[Q] = ydw_in[Q] * (1 - qu_factor)
        ydw_r[XD4] = ydw_in[XD4] * reject_factor
        ydw_r[XD5] = ydw_in[XD5] * reject_factor

    else:
        # the influent is too high on solids to thicken further
        # all the influent leaves with the sludge flow
        ydw_s[:] = ydw_in[:]
        ydw_s[TSS] = tssin

        # reject flow is zero
        ydw_r[:] = 0

    return ydw_s, ydw_r