**1. Introduction**

The issue regarding the quality and use of water has several aspects: the first option is the most common and of greater importance, than a simple view, which becomes the vital liquid

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

to survive and perform daily activities. Its quality directly affects the health and well-being of society [1]. The second corresponds to the use of water as the main raw material for the manufacture of some products and the operation of production processes. The interaction of water with the environment is influenced by the water quality that both society and the industrial sector confer on water.

potential measurements are key to determine the best operating conditions and understand the mechanisms of interface (contaminant-biopolyelectrolyte). In this chapter, the physicochemical characterization of six types of industrial wastewater is presented. Due to the complexity and variety of the contaminants present in these types of wastewater, only the

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

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In this chapter, the physicochemical characterization of six types of industrial wastewater and how to develop a treatment strategy for water recovery and how to add value to the byproducts formed are presented. The wastewater sampling protocol was followed as recommended by Mexican sampling standard (NMX-AA-003-1980). Residual water samples were taken from the nixtamalization industry (nejayote) that is dedicated to the manufacture of corn products and their derivatives. Another sample was collected from a candy factory that generates wastewater with a high content of dyes and suspended particles. The third case corresponds to a company dedicated to the recycling of cellulose and paper, which uses well water for its paper and cardboard manufacturing process. Another type of water sample was collected from the industry that is dedicated to the collection of hazardous waste that contains a greater proportion of oil and water. Finally, there is the sector dedicated to the metalworking industry and the semiconductor industry. Tested parameters were: total solids (TS), total dissolved solids (TDS), total suspended solids (TSS), turbidity, color, particle size, electrical conductivity (EC), zeta potential (ζ), total phosphorous (TP), biological oxygen demand

), chemical oxygen demand (COD), total organic carbon (TOC) and total nitrogen (TN). Tests were carried out following the current Mexican standard procedures that are equivalent

Chitosan (Ch) was obtained from waste shrimp shells using the adapted method proposed by

Zeta Potential from wastewater and biopolyelectrolyte data was recorded on a Stabino Particle Charge Mapping (Microtrac). The measurements were done at ambient temperature in Teflon cuvettes. Influence of pH on the zeta potential behavior of each biopolyelectrolytes was stud-

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.

to those published by EPA (AWWA standard methods, respectively).

ied within a pH range of 2–11 with 0.1 M NaOH and 0.1 M HCl [20].

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

**2.3. Zeta potential = f (pH) profiles of the industrial wastewater and chitosan**

**2.2. Extraction of chitosan biopolyelectrolyte**

the authors Goycoolea et al. [19].

wastewater treatability results of the pulp and paper industry are presented.

**2. Experimental**

(BOD5

**2.1. Wastewater sampling**

Each type of industry has a particular interest in the care of water quality and its reuse, which is why day by day, they require new strategies to treat and recycle the wastewater they generate in the different production processes [1]. Water quality is affected by various chemical substances that dissolve in water used in each stage of the manufacturing process.

In general, the main pollutants that are identified in the industrial wastewater are suspended particles, organic matter, heavy metals, the hardness of the water and fats and oils [2]. One of the pollutants frequently present in the industrial wastewater is suspended particles or solids. According to the nature of the production processes, the particles in suspension can be organic and inorganic and can be present in different particle sizes. The content of organic matter in industrial wastewater is attributed to the organic compounds (colorants, additives, nutrients, carbohydrates, etc.) that can be biodegradable or difficult to be degraded, and that are incorporated into the water at the time of use [3]. The levels of concentration in which these contaminants or undesirable substances are present in the wastewater are directly related to the operating conditions of the productive processes. The presence of these pollutants in the water causes an impact on the efficiency of the production processes, limits the reuse of water, increases the consumption of clean water, the discharge of the wastewater generated contaminates the water bodies, and this implies sanctions to the industry for exceeding the maximum permissible limits at the effluent discharge point [3].

There is an urgent need of environmentally friendly and cheaper technologies to eliminate the chemical toxicants from wastewater to improve the water quality.

Several methods that have been developed to eliminate these present pollutants from wastewater are as follows: reverse osmosis, solvent extraction, coagulation-flocculation, membrane separation, chemical precipitation, advanced oxidation processes, ion exchange, evaporation, electrolysis [4–6], photochemical [7], activated sludge [8], anaerobic and aerobic treatment [9, 10], electrodialysis [11], ultrasonic treatment [12], magnetic separation [13] and adsorption [14–16].

As part of the integral management of water in the industry, the development of environmentally friendly technologies is involved. In this chapter, we propose one of the strategies to restore the water quality (decontaminate, purify, remove undesirable substances for a specific use), which consists of the application of natural functional polymeric materials in physicochemical/electrochemical systems for the elimination of contaminants [17]. One of the simple and efficient methods for the separation of various types of contaminants is coagulation-flocculation, in which chemical substances are used as synthetic coagulant-flocculating agents (polyelectrolytes) [18]. However, in order to employ the different renewable sources, which are rich in polymeric materials and available in the region, as shrimp waste from the fishing industry will be used as a raw material for the production of functional polyelectrolytes and give it an added value. Due to the type of interactions that occur at a molecular level between the contaminants and the polyelectrolytes in the coagulation-flocculation processes, the zeta potential measurements are key to determine the best operating conditions and understand the mechanisms of interface (contaminant-biopolyelectrolyte). In this chapter, the physicochemical characterization of six types of industrial wastewater is presented. Due to the complexity and variety of the contaminants present in these types of wastewater, only the wastewater treatability results of the pulp and paper industry are presented.
