Basic ph meter pb 10

The biogas composition was determined with a gas chromatograph (GC-6890N, Agilent Inc. United States) equipped with a stainless steel column (1.5 m × 3 mm i.d. Carbon molecular sieve TDX-01: 1.5–2.0 nm) and a thermal conductivity detector (TCD) using argon as the carrier gas. Volatile organic acids (VFAs) were determined by the same GC-6890N equipped with a flame ionization detector (FID) and a capillary column (30 m × 0.25 mm, Agilent 19091N-133) using nitrogen as the carrier gas. The total solids (TS), volatile solids (VS.), pH (Sartorius basic pH meter PB-10, Germany), ammonia nitrogen (AN), total organic carbon (TOC), chemical oxygen demand (COD), and total Kjeldahl nitrogen (TKN) were determined according to standard methods (APHA and AWWA, 2005 ). Soluble COD (SCOD) of the PM feed was analyzed after vacuum filtration through 0.45 µm membrane filter paper (Borzooei et al., 2021 (link)). All measurements were conducted in triplicate, and the averaged data were presented.

For the LDH protease solutions, the temperature was measured by an infrared
thermometer (Raytek ST20 XB) and regular thermometer. The pH values were
determined using a Basic PH meter (PB-10, Sartorius, Germany). The temperature
and pH of the enzyme solutions were measured simultaneously.

The pK_a values of the compounds were determined by potentiometric titration using a pH meter (Basic pH Meter PB-10, Sartorius) calibrated with standard buffers of pH 4.01, 6.86 and 9.18 [26 (link)]. The compounds were dissolved in aqueous dimethyl sulfoxide (30% dimethyl sulfoxide) at constant ionic strength (0.15 M KCl). The solution was pre-acidified to approximately pH = 2 with 0.24 M HCl, and titrated until pH = 12 with 0.06 M KOH.

A stock dispersion with 50 mM UC₂₂AMPM was prepared by adding designed amounts of power-like samples and deionized water to a sealed Schott-Duran bottle equipped with a magnetic bar inside, followed by gentle agitation at 60 °C, yielding a low-viscosity emulsion-like dispersion. Then, the desired amount of inorganic metal salts was added into a 50 mM UC₂₂AMPM dispersion, followed by mechanical agitation for 12 h. The samples were left at 25 °C for at least 24 h prior to measurements. The dilute NaOH and HCl solutions were employed to adjust the pH of the UC₂₂AMPM–metal salt mixtures; the pH was determined by a Sartorius basic pH meter PB-10 (±0.01).

All optimal culture conditions for mycelial growth were determined by examining one factor at a time. PDA was used as the basal medium for the temperature research (20 mL of PDA was added to a 9-cm Petri dish), and PDB was used as the basal medium for the other culture condition experiments, including the verification test on temperature. Unless otherwise specified, the following conditions were performed: the medium was initially a pH of 6²⁵ [Adjusted with 1.0 N HCl or 1.0 N NaOH before sterilization and determined using a Sartorius Basic pH meter PB-10 (Germany). The following pH values were adjusted the same way], and 50 mL medium in a 250-mL flask was autoclaved at 121 °C for 30 min. All cultures were inoculated with 5% by volume seed culture and agitated at 120 rpm in 12 h darkness/12 h light with 50–55 lux at 20 °C for 5 d.
The mycelial growth rate for the temperature experiments on PDA was determined by colonial diameter, and the mycelia for the other treatments were harvested after 5 d by centrifugation for 10 min at 8000 × g to separate the sample from the liquid medium. The mycelial pellets were washed three times with distilled water and dried to a constant dry weight at 60 °C.