Industrial Water Reuse Research Articles

Process innovations and circular strategies for closing the water loop in a process industry

By implementing advanced wastewater treatment technologies coupled with digital tools, high-quality water is produced to be reused within the industry, enhancing process efficiency and closing loops. This paper investigates the impact of three innovation tools (process, circular and digital) in a Solvay chemical plant. Four technologies of the wastewater treatment plant “WAPEREUSE” were deployed, predicting their performance by process modelling and simulation in the PSM Tool. The environmental impact was assessed using Life Cycle Assessment and compared to the impact of the current industrial effluent discharge. The circularity level was assessed through three alternative closed-loop scenarios: (1) conventional treatment and discharge to sea (baseline), (2) conventional and advanced treatment by WAPEREUSE and discharge to sea, (3) conventional and advanced treatment by WAPEREUSE and industrial water reuse through cross-sectorial symbiotic network, where effluents are exchanged among the process industry, municipality and a water utility. Scenario 1 has the lowest pollutants’ removal efficiency with environmental footprint of 0.93 mPt/m3. WAPEREUSE technologies decreased COD by 98.3%, TOC by 91.4% and nitrates by 94.5%. Scenario 2 had environmental footprint of 1.12 mPt/m3. The cross-sectorial symbiotic network on the industrial value chain resulted in higher industrial circularity and sustainability level, avoiding effluents discharge. Scenario 3 is selected as the best option with 0.72 mPt per m3, reducing the environmental footprint by 21% and 36% compared to Scenarios 1 and 2, respectively.

Evaluation of return cooling water reuse in the wet cooled power plant to minimise the impact of water intake and drainage

The treatment and reuse of industrial water is a matter of great interest, given the severe shortage of water resources. It is widely acknowledged that power plants, particularly wet-cooled power plants, consume a significant amount of water. Therefore, research on the circulating cooling system (CCS) and the treatment of the return cooling water is of utmost importance. This study examined data on CCS inlet (water body), make up, and cooling water parameters, calculated a water balance, and predicted the hydrochemical quality of cooling tower blowdown water (CTBD). The study was conducted for an operating power plant to propose an effective treatment scheme for the return of CTBD to the process cycle. Additionally, it evaluated the possibility of recycling CTBD in the clarifier through laboratory modeling. Therefore, based on the results of this study, an effective treatment scheme is proposed to return CTBD to the technological cycle to ensure environmental sustainability. Recycled water was used as the water supply for the cooling tower, and a lime softening treatment was applied to clean the CTBD. According to the results, it is possible to recover quality indicators from a portion of the return cooling water after lime softening treatment. The novelty of this study lies in the successful demonstration of a lime softening regime that enables the blending of up to 25 % CTBD with make up water, without necessitating an increased CaO dose. This regime maintains TH levels at 2.2 mg-eq/dm³ and ensures that the discharge velocity of 0.7 m/s remains within regulatory standards. Additionally, it maintains standard concentrations of chloride (Cl⁻) and sulfate (SO₄²⁻) in CTBD at 200 mg/dm³ and 250 mg/dm³, respectively.

Innovative Photocatalytic Reactor for Sustainable Industrial Water Decontamination: Utilizing 3D-Printed Components and Silica-Titania Trilayer Coatings

Industrial activities generate enormous quantities of polluted effluents, necessitating advanced methods of wastewater treatment to prevent potential environmental threats. Thus, the design of a novel photocatalytic reactor for industrial water decontamination, purification, and reuse is proposed as an efficient advanced oxidation technology. In this work, the development of the active reactor components is described, utilizing a two-step sol–gel technique to prepare a silica-titania trilayer coating on 3D-printed polymeric filters. The initial dip-coated SiO2 insulator further protects and enhances the stability of the polymer matrix, and the subsequent TiO2 layers endow the composite architecture with photocatalytic functionality. The structural and morphological characteristics of the modified photocatalytic filters are extensively investigated, and their performance is assessed by studying the photocatalytic degradation of the Triton X-100, a common and standard chemical surfactant, presented in the contaminated wastewater of the steel metal industry. The promising outcomes of the innovative versatile reactor pave the way for developing scalable, cost-effective reactors for efficient water treatment technologies.

Water strategies and management: current paths to sustainable water use

Freshwater is unquestionably the most crucial resource essential for the sustenance and advancement of humankind. This invaluable entity surpasses all societal, economic, and environmental domains, consequently rendering it a ubiquitous good. Globally, it has been estimated that the industrial sector employs approximately 20% of the available freshwater. The principal aim within the industrial domain is to maximize production efficiency, rather than prioritizing the enhancement of water conservation and efficiency. Research suggests that a favorable association exists between the monetary investments made in technological improvements for industrial water treatment and reuse and a profitable return on investment that is sustained over a prolonged duration. This could plausibly explain the dearth of willingness exhibited by some corporations in dedicating resources to this vital issue. The objective of this study is to explicate the notion of sustainability concerning water management that can be operationalized in the context of Pakistan, while delving into the latest advancements in the sphere of sustainable management practices. This research endeavor shall serve as an instructive source for executives, entrepreneurs, and vested parties in various industrial domains to propel their endeavors toward sustainable practices while simultaneously achieving optimization and surpassing the benchmarks set by national regulations and international establishments. This investigation has illuminated the imperative of executing an all-encompassing water management strategy that incorporates the ecological, financial, and societal dimensions as the essential constituents of viability in industrial water utilization. This work ought to possess a worldwide scope, bearing in mind the ubiquitous character of industrial practices in the epoch of globalization.

Sustainable Water Use in a Fruit Processing Plant: Evaluation of Microbiological and Physicochemical Properties of Wash Water after Application of a Modular Water Recovery System

The reuse of wash water in the agri-food industry is in line with sustainability goals through the reduction of the water footprint. Depending on the production process and raw material type, wash waters may exhibit severe biological and physicochemical contamination. The use of traditional methods of chlorine disinfection of water may be linked to the formation of hazardous by-products. The recycling of contaminated water should be supported by the evaluation of physicochemical and microbiological parameters before and after application of a treatment to validate the process. This study aimed to assess physicochemical and microbiological properties of rinse water from a post-harvest processing plant before and after applying an innovative modular water treatment system. The test material was washing water after apple rinsing obtained from a post-harvest processing plant (Northern Poland). The water recovery system included a wash water tank, a sand pre-filter, an ultrafiltration system, and an ozonation tank. No microorganisms were found in the treated water. The physicochemical properties of the water were also improved: pH, conductivity, turbidity, ammonium ion, bromide, and nitrate content. The results indicate that rinse water from the fruit industry may be effectively purified using the tested purification system and reused in production processes.

Insights into coagulation, softening and ozonation pre-treatments for reverse osmosis membrane fouling control in reclamation of textile secondary effluent

Pre-treatment was an effective strategy to mitigate membrane fouling, while controversial fouling control performance and mechanism still restricted its application. Herein, coagulation, softening and ozonation pre-treatments were applied to mitigate reverse osmosis (RO) fouling in reclamation of textile secondary effluent. The results showed coagulation pre-treatment negligibly alleviated membrane fouling by dosing FeCl3 coagulant due to the low coagulation efficiency and dissolved organic carbon (DOC) removal (only 11 %) toward effluent organic matter (EfOM) with low molecular weight (2300–6145 Da). Unexpectedly, pre-ozonation caused more severe RO fouling with the increasing ozone doses owing to the enhanced bridging action of divalent cations between membrane and ozonated EfOM; however, the opposite phenomenon was observed when divalent cations were removed by softening due to the preferential removal of biopolymers, the decrease in molecular weight and hydrophobicity of EfOM. Especially, at ozone dose of 1.0 mg O3/mg DOC, flux loss and irreversible fouling resistance enhanced by 8.60 % and 25.4 %, but markedly reduced by 24.0 % and 41.2 % in the absence of divalent cations, respectively. Extended DLVO (XDLVO) theory further unveiled the different roles of pre-treatments in RO fouling control was mainly due to the variation of adhesion interfaces between RO membrane and foulants, especially for the Lewis acid-base (AB) interaction energy. We proposed that softening + ozonation pre-treatment was effective to control RO fouling. More importantly, the reclaimed water satisfy the national standard of China (GB/T 19923–2005) for industrial water reuse after softening + ozonation + RO membrane treatment, which is promising to reclaim textile wastewater.

Heterogeneous photosensitization for water reuse in cellars: evaluation of silica, spongin, and chitosan as carrier material.

Photosensitization, a powerful oxidation reaction, offers significant potential for wastewater treatment in the context of industrial process water reuse. This environmentally friendly process can be crucial in reducing water consumption and industrial pollution. The ultimate goal is to complete process water reuse, creating a closed-loop system that preserves the inherent value of water resources. The photosensitized oxidation reaction hinges on three essential components: the photosensitizer, visible light, and oxygen. In this study, we assess the performance of three distinct materials-silica, chitosan, and spongin-as carrier materials for incorporating the phthalocyanine photosensitizer (ZnPcS4) in the heterogenous photosensitization process. Among the three materials under study, chitosan emerged as the standout performer in reactor hydrodynamic performance. In the photooxidation process, the photosensitizer ZnPcS4 exhibited notable efficacy, resulting in a significant reduction of approximately 20 to 30% in the remaining COD concentration of the cellar wastewater. Chitosan demonstrated exceptional hydrodynamic characteristics and displayed a favorable response to pH adjustments within the range of 8 to 10, outperforming the other two carrier materials. To further enhance the efficiency of continuous operation, exploring methods for mitigating photosensitizer bleaching within the reaction medium and investigating the impact of different pH values on the process optimization would be prudent.

Antifouling treatment enables membranes to deal with oil and grease

PPG Industries Inc, which supplies paints, coatings and speciality materials, has developed and introduced a high-performance ultrafiltration (UF) membrane and filter elements that help to improve the reuse of industrial process water.

Analytical framework for planning water reuse in the food industry with application to a cheese production case study

Global water scarcity is becoming an increasingly pressing environmental concern. With FAO reports showing that 70% of water consumption is related to agriculture, and an additional 20% to industrial use, it is clear that the food industry needs to manage its water usage efficiently. Increased reuse and recycling of effluent water in food processing is an important part of this. However, several challenges related to product quality, logistics, legislation, and implementation prevent many companies from doing so. We present an analytical framework to minimize freshwater usage and maximize water reuse within the context of production planning. We identify several theoretical principles behind efficient water usage and combine these with insights from previous literature. The resulting framework is specifically aimed as the basis for easy-to-use analytical tools. Applying our framework to a cheese production case study with water recovered from whey, we demonstrate freshwater savings of over 67%. We also derive various insights to guide managers on setting the right targets for their water reuse planning. In general, the framework supports the identification of potential water savings achieved by short-term changes to production plans as well as long-term changes to water reuse infrastructure.

Integration of Pre-Treatment with UF/RO Membrane Process for Waste Water Recovery and Reuse in Agro-Based Pulp and Paper Industry

This recent study aims to evaluate the efficacy of membrane filtration on recovery of water resource from agro-waste such as bagasse, crop-based pulp and paper mill waste. A mini pilot scale membrane system having a combination of pre-treatment filter unit (pre-filter, sediment filter and pre-carbon filter), ultra-filtration and reverse osmosis with spiral wound configuration were employed to evaluate the water reuse efficacy of effluent coming from the secondary clarifier of the conventional treatment plant of the mill. The operational conditions were optimized using Taguchi method at pH 8, temperature 32 °C, and pressure 2 bar and a flow rate of 60 l/hr. The qualities of the effluent from the secondary clarifier, and the permeate from both the combination, viz. Combination 1 (pre-treatment + ultra-filtration) and Combination 2 (pre-treatment + ultra-filtration+ reverse osmosis) were analyzed and the percentage reduction in pH, TDS, TSS, BOD, COD, Color, Lignin, Potassium and Sodium were calculated. The elimination of TDS, COD and BOD with Combination 1 was not promising (<22%). However, the installation of a RO membrane greatly reduced (>88%) the contaminants in both paper mill effluents. The obtained qualities of water from all the combinations were compared with the tolerance standard for reuse as process water. The quality of effluent from the secondary clarifier did not agree with any class of water quality. The permeate from the combination of pre-treatment and UF sufficiently reduced the TSS to reach the requirement. However, the combination of (pre-treatment + UF + RO) adequately complied with the quality standard required for reuse in the making of all grades of paper.

Water reuse in the textile industry with integrated treatments: membranes and advanced oxidation processes

Water reuse in the textile industry with integrated treatments: membranes and advanced oxidation processes

Eco - Industrial parks in Iraq

The idea of eco-industrial parks developed and became part of the planning process for the industrial city and this came as a reaction to the adverse effects of industry on the environment if this pollution continues, it will negatively affect our lives and future generations. Its importance is highlighted by achieving the principles of sustainable development by realizing the idea of a closed industrial loop in the design of the industrial city and making it self-sufficient as possible in terms of energy consumed to perform industrial operations. In addition to recycling industrial waste and benefiting from it with the idea of product and by-product where the product is considered a by-product (waste industrial) a raw material for another industry. The research paper dealt with the concept of the environmental industrial city. To study is aimed to examine the reality of planning for the industrial cities in Iraq and the environmental industrial cities around the world, and extract the most important solutions and strategies that can be followed in the Iraqi industrial cities to make them environmental industrial cities. Its main goals are embodied in preserving environmental resources and not wasting them to preserve the rights of future generations and Sustainable long-term economic success, in addition to providing a clean environment free of pollution in Iraq. In comparison with the ecological industrial cities around the world and the strategies and objectives of the proposed industrial cities in Iraq, we find: The use of clean energy, reuse of waste resulting from industrial processes, water reuse, and other main principles should be included in the Iraqi industrial cities, in addition, to set up units for treating heavy water and waste and power and purification plants.

Strategy towards the use of ultrafiltration and reverse osmosis for industrial water recovery and reuse as part of the Green Deal Implementation

Strategy towards the use of ultrafiltration and reverse osmosis for industrial water recovery and reuse as part of the Green Deal Implementation

Combined process of chemically enhanced sedimentation and rapid filtration for urban wastewater treatment for potable reuse

ABSTRACT The objective of this study is to propose a new post-treatment of effluents from Upflow Anaerobic Sludge Blanket (UASB) using rapid filtration, aiming at the production of water for potable reuse. The final quality of the effluent produced by the treatment using gravel, sand, clinoptilolite and activated carbon associated with disinfection was evaluated by physical chemical analysis, heavy metals and persistent organic contaminants. Experiments were carried out in jar test, filter operation time, evaluation of the efficiency using peracetic acid and free chlorine as disinfectant and all results were statistically analysed. The best conditions were those using 20 mg/L of ferric chloride and natural pH of the effluent (≈ 7.0), which resulted in less reagent consumption. The use of intermediate fund discharges made it possible to obtain approximately 91% of recovered water efficiency. The effluent treated under these conditions showed DOC <2.0 mg/L, COD <1.0 mg/L, BOD <1.0 mg/L, turbidity <1.0 NTU, TSS <1.0 mg/L, ammonia <0.1 mg/L, total phosphorus <0.1 mg/L and surfactants <0.1 mg/L. The disinfection process with free chlorine and PAA allowed the total inactivation of faecal coliforms and total coliforms. The treatment using rapid filtration with disinfection by chlorine reached the appropriate level for urban, environmental, industrial and indirect potable water reuse.

Comprehensive treatment of latex wastewater and resource utilization of concentrated liquid

Latex wastewater is a kind of refractory organic wastewater containing high concentrations of organics and ammonia nitrogen. In this work, the combined process of forward osmosis (FO) and reverse osmosis (RO) was designed to treat the latex wastewater in the whole process, achieving the water recovery rate of 99% and basically no waste discharge after the catalytic oxidation process. The turbidity of the latex wastewater was decreased to below 1 NTU by microfiltration pretreatment, and then using MgCl2 worked as the draw solution for FO process to treat the latex wastewater. Different operation conditions including adding acid or scale inhibitor as the pretreatment methods were conducted to improve the treatment performance of the combined process. After the treatment of the whole process, the concentration of COD was less than 20 mg⋅L−1, the concentration of NH3-N was less than 10 mg⋅L−1, and the concentration of TP was less than 0.5 mg⋅L−1 for the treated latex wastewater. The water quality met standards of industrial water reuse after the complete analysis of the treated latex wastewater, meanwhile, useful substances of L-Quebrachitol (L-Q) were successfully extracted from the concentrated solution. Therefore, the combined process of FO and RO could realize the efficient treatment and reuse of latex wastewater, which provided with some important guidance on the industrial application.

Impact of Water Saving Policy on Water Resource and Economy for Hebei, China Based on an Improved Computable General Equilibrium Model

Hebei Province of China is facing a severe water resource shortage, making it urgent to formulate economical and effective water conservation policies. However, few studies have focused on analyzing the resource and economic impacts of a water policy. This study developed an improved computable general equilibrium (CGE) model with an extended water resources module as a policy analysis tool. The extended water resources module includes different water resources as commodities and water sectors, and introduces a substitution mechanism among the water resources. Policy scenarios containing different policy types and policy objects were established, including water price, technology (tech) improvement, structure adjustment, and water reuse policies in primary, secondary, and tertiary sectors. The impact on the water resource and economy of the scenarios was analyzed using the CGE model. The recommended policies include: an agricultural technology improvement policy that decreases groundwater usage by 240 hm3; an industrial technology improvement policy under which water usage per 10,000 CNY of industrial added value decreases by 13%; an industrial water reuse policy that increases unconventional water usage by 20%; and a structure adjustment policy to increase the proportion of the tertiary sector. The study provides an analysis tool for simulating and evaluating a water resource policy.

Application of Nanofiltration and Reverse Osmosis Membranes for Tannery Wastewater Reuse

Tanneries produce large amounts of wastewater with high concentrations of suspended solids, organic matter, and salts. Treatment and reuse of these effluents are of great importance to preserve water resources and save costs. Although suspended solids and high percentages of organic matter can be eliminated by physico-chemical and biological processes, refractory chemical oxygen demand (COD) and salts will remain in the wastewater after these processes. In particular, chloride and sulphate ion concentrations may hinder the treated wastewater from being reused or even discharged according to legal standards. In this work, two nanofiltration membranes and two reverse osmosis membranes are tested to assess these technologies as regeneration processes for biologically treated tannery wastewater. Permeate flux and rejection of organic matter and ions were measured at different operating conditions (transmembrane pressure and cross-flow velocities) at both total recycle and concentration modes. Results showed that the difference between permeate fluxes of nanofiltration (NF) membranes and reverse osmosis (RO) membranes was very high. Thus, at 20 bar and 1.77 m·s−1, the permeate flux of the two tested NF membranes in the total recycle mode experiments were 106 and 67 L·m−2·h−1, while the obtained permeate fluxes for the RO membranes were 25 and 18 L·m−2·h−1. Concerning rejections, RO membranes rejected almost 100% of the salts, whereas NF membranes reduced their rejection when faced with increasing concentration factors (salt rejection between 50–60% at the highest concentration factor). In addition, the fouling of RO membranes was lower than that of NF membranes, recovering more than 90% of initial permeability by only water rinsing. In contrast, chemical cleaning was necessary to increase the permeability recovery of the NF membranes above 90%. The considerably lower rejections and the higher membrane fouling of the NF membranes lead us to conclude that reverse osmosis could be the most feasible technique for water reuse in the tannery industry, though the permeate fluxes are lower than those achieved with NF membranes.

Optimisation of Water-Energy Networks in Process Industry: Implementation of Non-Linear and Multi-Objective Models

The improvement of water and energy use in the industrial sector is an important concern to improve the overall techno-economic performance of single plants. The most recent EU strategy for energy system integration has been treating these issues in the redaction of its first pillar, which is based on the relations between the promotion of circular economy and energy efficiency and it has as specific objectives the promotion of waste heat recovery and energy recovery from wastewater. Although on the context of research and industrial appliance both waste heat recovery and water recycling and reuse have been extensively explored, it is still verifiable a lack of comprehension and application of methods to simultaneously improve the use of both water and energy in a plant. In this work, two approaches for the solving of an optimisation problem related to the improvement of water and energy use in a process industry plant (three water-using processes) are implemented. These approaches consist on the development of a mixed-integer non-linear programming (MINLP) model and a multi-objective programming (MOP) model using the Python language. In addition, a complementary approach based on the development of a non-linear programming (NLP) model for further heat integration is also developed. Within the three applied methodologies (MINLP, MOP and integrated MINLP and NLP), the integrated MINLP and NLP model was the one in which the most favourable results were obtained, with 33.7% freshwater savings, 73.2% energy savings and 67.2% total economic savings.

Opportunities and Challenges for Industrial Water Treatment and Reuse

As the impact of water scarcity in the United States (U.S.) continues to grow through the 21st century, it is critical to develop strategies to reduce water use and improve the security of water resources. One such strategy is to diversify the sources from which water is supplied. Industrial withdrawals represent the fourth largest category of U.S. water use, the majority of which is sourced from fresh surface and groundwater. In this study, we critically explore the potential of industrial wastewater to serve as an alternative water resource through direct treatment and reuse. We begin by reviewing the state of the art of water use, treatment, and reuse across six representative industries: food and beverages, primary metals, pulp and paper, petroleum refining, chemicals, and data centers and campuses, highlighting key challenges and opportunities toward the expansion of reuse. We then employ a technoeconomic assessment of water treatment processes to analyze the capital investment, operating and maintenance costs, levelized cost of water, and electricity consumption of three specific industrial plants as case studies to better understand where research can promote impactful innovation. Finally, drawing together the results of our literature review and technoeconomic analyses, we provide a broad outlook on the future of industrial water reuse and discuss strategies for its expansion.

A study of inline chemical coagulation/precipitation-ceramic microfiltration and nanofiltration for reverse osmosis concentrate minimization and reuse in the textile industry.

Reverse osmosis concentrate (ROC) is one of the major drawbacks in membrane treatment technologies specifically due to the scale-forming ions. It is important to remove these ions from ROC to enhance total water recovery and reuse in the textile industry that is the largest water-consumer and polluter industry. In this work, coagulation/high pH precipitation (CP) integrated with ceramic microfiltration (CMF) was studied as a pre-treatment method followed by nanofiltration (NF) to increase the efficiency of water recovery. To prevent organic fouling, ferric chloride (FeCl3) was applied at a concentration of 3 mM, and ceramic membranes were used for the removal of non-precipitating crystals and/or suspended solids (at high pH) before the NF processes. The CP-CMF method successfully removed calcium (Ca2+), magnesium (Mg2+), silica (SiO2), and TOC up to 97, 83, 92, and 87% respectively, which resulted in higher performance of the NF process. Moreover, this method provided higher flux at lower pressure that ultimately increased overall water recovery of the NF process to achieve near-zero liquid discharge (n-ZLD). A cost-benefit estimation showed that a high-quality effluent (COD<5 mg/L; conductivity 700<μS/cm; negligible residual color) can be generated and recycled in the textile industry at an economical cost (approximately 0.97 USD/m3). Therefore, ROC minimization and water recovery can help to achieve n-ZLD using the CP-CMF/NF method.