Assessing demineralization treatments for PVC effluent reuse in the resin polymerization step

Abstract

To reduce fresh water consumption in a polyvinyl chloride (PVC) plant, the effluent from a biological treatment must be demineralized to be re-used in the resin polymerization process. Demineralization is a critical process, since the quality and the stability of the PVC resins are highly influenced by the water quality used in the process. The main target values for water parameters are the following: conductivity <10 μScm, TOC < 10 mg L, and Al < 0.1 mg L. To achieve this quality, several reverse osmosis membranes from different materials and suppliers were tested and compared in the demineralization treatment. Polyamide membranes showed higher salt rejection compared to cellulose acetate membranes yielding both types similar flux and permeability. Two-pass reverse osmosis treatment was necessary to reach conductivities lower than 10 μS cm. On the other hand, a good quality effluent for reuse was obtained by combining RO and ionic exchange resins. Results showed that good quality PVC resins in terms of color, granulometry, porosity, and bulk density were obtained when demineralized water from two-pass reverse osmosis was used as fresh water, proving the feasibility of the effluent reuse in the PVC industry.

Estudo De Caso: Inovação Para Diversificação Em Uma Indústria Química À Luz Da Abordagem Neoschumpeteriana

“…A tecnologia de resina de troca iônica é uma técnica que apresenta bons resultados ao ser aplicada para o tratamento de águas residuais, por promover a remoção de diferentes espécies, desenvolver uma cinética rápida, proporcionando a recuperação deste efluente para outros fins. Desta forma, este método torna-se eficaz para a reutilização de resíduos, como por exemplo, na indústria de policloreto de vinila localizada na Espanha [BLANCO, 2017]. O processo de fotólise direta apresenta elevada eficiência, quando acrescentada na cadeia de tratamento de águas industrias.…”

A Joint Computer-Aided Simulation and Water-Energy-Product (WEP) Approach for Technical Evaluation of PVC Production

“…The suspension PVC production process has the peculiarity that most of the water entering the process is demineralized. This water goes through a purification process in which minerals and salts are removed because they interfere with the quality and stability of the resin in the reaction stage [36]. If the amount of raw water used to produce 1933 m 3 daily were considered, the FWC index would increase to 2.83 m 3 per ton, which would put the process closer to the values reported in the literature.…”

Extraction and Characterization of Microplastics from Portuguese Industrial Effluents

“…MPs have also been detected in remote areas, including polar regions, such as Antarctica of the southern ocean and on the deepest parts of the ocean at the Mariana Trench, North Pacific gyre, and south pacific islands, with particularly high concentrations [ 5 , 6 , 7 ]. Even in the world´s highest hills, the Tibetan plateau, MPs have been detected within its rivers and lakes [ 8 ]. Wastewater treatment plants (WWTPs) can mitigate the spreading of MPs by retaining part of them (larger dimensions) with screens and filters [ 9 , 10 , 11 ].…”