**2.4. Wastewater coagulation-flocculation tests using chitosan**

The performance of cationic chitosan biopolyelectrolyte in the coagulation-flocculation of wastewater from the cellulose and paper recycling industry was carried out using 20 mL of residual water at pH 5.4 and in different doses of chitosan extracted from the shrimp shells. After each addition of chitosan, the mixture of residual water with chitosan was stirred at 200 rpm for 2 min and subsequently at 50 rpm for 20 min. For the evaluation of the quality of the treated water, a sample of the supernatant was extracted [21].

**Parameter Nixtamalization**

Alkalinity (mg/L CaCO<sup>3</sup>

Chemical Oxygen Demand, COD

Biochemical Oxygen Demand, BOD5

**Parameter Recycled cellulose and** 

Biodegradability (BOD5

Alkalinity (mg/L CaCO<sup>3</sup>

(mg O<sup>2</sup> /L)

(mg O<sup>2</sup> /L) **wastewater**

Temperature (°C) 38 Temperature (°C) 26 Sedimentable solids, SS (mL/L) 850 SS (mL/L) 25 Total Dissolved Solids, TDS (mg/L) 47,200 TDS (mg/L) 12,743 Total Suspended Solids, TSS (mg/L) 2000 TSS (mg/L) 2342 Turbidity (FAU) 1500 Turbidity (FAU) 1676

) 1025 Alkalinity (mg/L CaCO<sup>3</sup>

28,450 COD (mg O<sup>2</sup>

(nm)

Innovation of Coagulation-Flocculation Processes Using Biopolyelectrolytes and Zeta Potential…

(mg O<sup>2</sup>

Electric conductivity, EC (mS/cm) 5.42 EC (mS/cm) 1.30 ζ (mV) −10.5 ζ (mV) −25.7

Color (Pt-Co) 8580 Color (Pt-Co) 6572 pH 10.0–12.0 pH 6.7

Total Organic Carbon, TOC (mg C/L) 9836 TOC (mg C/L) 250

Total Phosphorus, TP (mg P/L) 1321 TP (mg P/L) 142 Total Nitrogen, TN (mg N/L) 418 TN (mg N/L) 120

**paper wastewater**

Temperature (°C) 35 Temperature (°C) 28 Chlorides (mg/L) 900 Zn (mg/L) 10.2 Total hardness (mg/L) 3800 Cu (mg/L) 12.2

Fats and oils (mg/L) 11 Fats and oils (mg/L) 6732 TSS (mg/L) 500 TSS (mg/L) 15,000 TDS (mg/L) 3500 TDS (mg/L) 3500 SS (mL/L) 438 SS (mL/L) 438 Turbidity (FAU) 560 Turbidity (FAU) 350 EC (mS/cm) 1.00 EC (mS/cm) 2.00 ζ (mV) −25.8 ζ (mV) −2.1

2700 BOD5

/COD) 0.27 Biodegradability (BOD5

) 850 Alkalinity (mg/L CaCO<sup>3</sup>

Particle size of dissolved part (nm) 100–600 Particle size of dissolved part

**Parameter Candy Industry** 

http://dx.doi.org/10.5772/intechopen.75898

) 500

/L) 786

/L) 653

**Parameter Recycled oils** 

/COD) 0.83

) 100

**wastewater**

300–800

**wastewater**

131
