2100q portable turbidimeter

Prior to biofilm growth and mixing experiments, the BML surface water and FFT pore water were characterized by measuring pH, electrical conductivity (EC), dissolved oxygen (DO), major cations and anions, naphthenic acids (NAs), and turbidity (in surface water only). pH and EC were measured using a Fisher Scientific Accumet AR50 Dual Channel pH/Ion/Conductivity Meter. DO was evaluated using a YSI 52 Dissolved Oxygen Meter (YSI Incorporated, Yellowsprings, OH, USA). Major cation analysis was conducted at the Natural Resources Analytical Laboratory (NRAL) at the University of Alberta. Samples were filtered with 0.45 µm nylon filters and analyzed for Na⁺, K⁺, Ca²⁺, and Mg²⁺ via inductively coupled plasma optical emission spectrometry (ICP-OES) (Thermo iCAP 600 series, Thermo Fisher Scientific, Cambridge, United Kingdom). Filtered samples (using 0.45 µm nylon filters) were analyzed for major anions (Cl⁻, SO₄-S, NH₄-N, NO₂-N, NO₃-N, and PO₄-P) at NRAL with a Thermo Gallery Plus Beermaster Colorimetric Autoanalyzer (Thermo Fisher Scientific, Vantaa, Finland). NAs were determined using Fourier-transform infrared spectrometry (FTIR) (Spectrum 100 FT-IR Spectrometer, PerkinElmer, Shelton, CT, USA) following the procedure described in Ripmeester and Duford [31 (link)]. Turbidity was measured using a HACH 2100Q Portable Turbidimeter (Loveland, CO, USA).

Separation performance was conducted in a dead-end filtration cell, Steritech HP 4750 pressure membrane test cell (Sligo, Rathquarter, Ireland). The active membrane area in the cell was 14.6 cm². The membranes were tested for pure water flux and turbidity removal with synthetic turbid water. The pressure was varied from 0.2 bar to 1.0 bar, while the initial turbidity was varied from 80 NTU to 140 NTU. The membranes were also used for the treatment of raw restaurant wastewater. Chemical oxygen demand (COD) was analyzed using a spectrophotometer, Hach DR6000 UV-VIS (Loveland, CO, USA), while turbidity was analyzed with a turbidity meter (Hach 2100Q Portable Turbidimeter).
The water flux was calculated using Equation (1), while turbidity and COD were calculated using Equation (2).
$$J_w=\frac{V}{At}$$
where $J_w$ (L/m²/h) and V (L) are the water flux and the permeate volume, respectively. The active membrane area A is measured in m², while the filtration time t is in h.
$$R=\frac{\left(C_f-C_p\right)}{C_f}\times 100$$
where R is the rejection in %, C_f is the initial turbidity or COD in the feed, and C_p is the final turbidity or COD in the permeate.

Free and total chlorine were measured using the N,N-diethyl-p-phenylenediamine (DPD) Method (Pocket ColorimeterTM II, Hach, Loveland, CO, USA); pH and temperature (ExTech 407227, Extech Instruments, Nashua, NH, USA); hardness (ethylenediaminetetraacetic acid (EDTA) Titration Method, Hach, Loveland, CO, USA); turbidity (2100 Q Portable Turbidimeter, Hach, Loveland, CO, USA); ferrous and total iron (1, 10 phenanthroline Method, Hach, Loveland, CO, USA); and absorbance and ultraviolet transmittance (UVT) of the test water at 255, 265, and 280 nm (DR6000 UV-VIS spectrophotometer, Hach, Loveland, CO, USA).