1. IntroductionWater resources are the most significant global resource facing environmental issues in the 21st century; it is expected that, by 2050, at least one-quarter of the world’s population will be affected by freshwater shortages. In recent years, the acceleration of industrialization and rapid population growth have led to an increasingly prominent contradiction between water supply and demand [1,2] and, at the same time, the discharge of urban domestic sewage and industrial wastewater has also surged, leading to serious environmental problems and health hazards [3]. Water resources are at the core of national economic security, and in July 2021, China’s National Development and Reform Commission issued the 14th Five-Year Plan for the Development of the Circular Economy, which highlighted the importance of vigorously developing the circular economy and promoting resource conservation and intensive recycling [4]. This requires adequate recycled water infrastructure, a shift from a one-way, straight-line process of “resource–product–waste” to a feedback cycle of “resource–product–waste–renewable resources” [5]. Although recycled products are considered environmentally friendly by consumers and are generally positively evaluated, consumers do not like to use them [6,7]. Recycled water is also regarded as repugnant and ostracized by the public as one of the recycled products; for example, San Diego County’s colossal investment in recycled water infrastructure failed in the 1990s due to massive public protests. Similarly, Australia’s recycled water infrastructure failed, as more than 60% of the public voted against it [8]. It can be seen that technological breakthroughs do not mean the successful implementation of recycled water reuse projects. The successful implementation of recycled water reuse must reasonably and effectively enhance the public’s willingness to reuse. In China, although recycled water has not yet triggered massive opposition, scholars have found that the public has deep-rooted stereotypes against recycled water [9], and even the willingness to consume agricultural products irrigated with recycled water is low [10]. Building sufficient recycled water infrastructure is a critical way to solve the problem of water shortage and water pollution in the process of social and economic development [11]. To avoid the failure of recycled water investments due to public resistance, consumers must be guided to use recycled water actively.The primary determinant of low public acceptance of recycled water is the “disgust factor”, which can be defined as an aversion or psychological reaction [12]. Wester et al. suggest that the widespread adverse public response to recycled water is mainly due to aversion, especially pathogen aversion [13]. In other words, public concerns about pathogens can be considered the primary driver of emotional reactions to recycled water, which determines the acceptance of water reuse and other cognitive factors. The success of Windhoek’s recycled water for drinking is partly because it meets extremely high specifications and security and health risk issues have been adequately addressed [14]. In contrast, Rozin et al. argue that scientific assurance of recycled water quality and safety does not eliminate the perception of contamination due to “mental contagion”, meaning that advances in water purification technology alone do not automatically guarantee public acceptance [15]. However, public perceptions are shaped by social processes involved in water development, including people’s experiences and the extent to which society discloses information related to recycled water [16]. Therefore, it is crucial to analyze public perceptions of recycled water from an informational perspective, which can provide a more comprehensive understanding of the factors that contribute to public resistance to recycled water reuse.User reviews mainly refer to the reviews about products made by consumers after purchasing or using them. Studies have shown that the information revealed by user reviews affects the public’s cognitive behavior [17,18], and consumers tend to pay more attention to user reviews for products for which it is difficult to obtain product quality information [19]. At present, consumers have limited channels to understand recycled water, and user reviews have become the most direct way for consumers to understand recycled water and evaluate its quality. Relevant studies have considered product characteristics and product information when analyzing the public’s willingness to use recycled water [20]. Still, few studies have explored the impact of user comments on the public’s willingness to reuse water. Hou et al. have confirmed that user comments play an essential role in the construction of recycled water infrastructure [21], but the mechanism by which user comments affect the public’s recycled water use behavior needs to be further clarified. Therefore, this study considers user reviews and analyzes the effect of user comments on the construction of recycled water infrastructure, which is conducive to the promotion of recycled water and the construction of recycled water infrastructure and, ultimately, sustainable social and economic development.The purchasing process of consumers involves complex psychological activities [22]. By reviewing the literature, it was found that most previous studies have used questionnaire surveys or text mining to obtain research data [23], through which it isn’t easy to analyze the thinking process underlying individual decision-making comprehensively. The eye–mind hypothesis states that fixation indicates thinking and information extraction and that the eye can genuinely reflect an individual’s cognitive processes. The longer the fixed time, the deeper the degree of cognitive processing [24]. When consumers look at review information, they are performing cognitive processing on the review content. Eye-tracking technology can capture and record the eye movement process of consumers browsing user reviews to form objective data, providing an effective way to analyze the processing of information by consumers [25]. Therefore, in this study, we simulate a recycled water purchase scenario, and conduct eye-tracking experiments to obtain research data and analyze the psychological mechanism underlying the process of public consumption more objectively, in order to put forward reasonable suggestions for the construction of recycled water infrastructure to guide practice. Specifically, we aim to answer the following two questions:(1)

What affects the public’s willingness to buy recycled water?

(2)

How do user reviews affect a consumer’s willingness to accept?

2. Theoretical Background and Research AssumptionsThe American scholar Davis (1986) has proposed the Technology Acceptance Model (TAM) to analyze the influence of an individual’s perceptual and affective factors on the acceptance of information technology [26]. The core idea is that a user’s willingness to use information technology is influenced by a combination of two factors: perceived usefulness and perceived ease of use [27]. Perceived ease of use reflects how easy or difficult consumers perceive information systems to be to operate, whereas perceived usefulness refers to the fact that the more users subjectively approve of information systems and technology products, the more likely they are to accept them. The TAM theoretical model is, to some extent, effective in explaining the acceptance behavior of individuals regarding technology products. However, people’s choices are becoming more and more diverse. From the consumer’s point of view, they will consider not only the usefulness and ease of use but also the cost and benefits of the technology, which is a limitation of the technology acceptance model in explaining consumer purchase behavior. Based on this, Kim et al. (2007) have proposed the Value-based Adoption Model (VAM), the core idea of which is that a user’s willingness to use a technology (e.g., mobile internet) is influenced by a combination of payoffs and benefits [28]; that is, the user’s perceived value. The combination of the TAM and VAM models can consider both technology and consumer perceived value, which provide essential insights to explain public behaviors, such as those related to recycled water use.According to the TAM theory, an individual’s acceptance of recycled water is influenced by his perceived usefulness of sewage treatment technology and recycled water. Recycled water from sewage treatment can increase revenue and reduce expenditure, reduce sewage discharge, effectively relieve the pressure of water shortage and environmental pollution, and realize a virtuous cycle of water resources [18]. Recycled water is often perceived as “green” and “environmentally friendly” by consumers [29], and individuals who perceive recycled water to be beneficial to the environment tend to be more willing to use recycled water for non-potable purposes [30]. Liu et al. think that individuals’ environmental value of recycled water reuse will directly affect their attitude [31]. However, some scholars have found that people prefer to use recycled water treated by natural water treatment processes (e.g., treated effluent discharged into aquifers or reservoirs), because they believe that discharging to aquifers can further purify treated wastewater, whereas those who are concerned about the potential environmental impact of recycled water are more in favor of replenishing reservoirs to avoid possible pollution of rivers and aquifers [15]. We speculate that this may be related to distrust of wastewater treatment technologies to solve water problems. An earlier study found that trust in technology was associated with greater acceptance of drinking recycled water [32], so we hypothesize that the higher the public’s perceived usefulness of wastewater treatment technology to solve water problems, the more likely they may be to reuse. Based on this, this paper puts forward the following hypotheses to be verified:H1: 

Consumers’ perceived usefulness of sewage treatment technology and recycled water reuse positively influences a consumers’ willingness to purchase recycled water.

According to the VAM model, consumers will make a comprehensive assessment of the benefits and the costs when purchasing recycled water and make a purchase decision by comparing the benefits to the costs; in other words, consumers will evaluate the quality and cost of using recycled water. Chi et al. found that price was a crucial determinant in purchasing of recycled production by females when they studied consumer perceptions of its value [33]. Price is the monetary cost that consumers must pay to use recycled water. Garcia–Cuerva et al. found that residents would accept recycled water for reuse to save money on water bills when the price of recycled water was significantly lower than tap water [34]. In contrast, Hou et al. found that residents’ willingness to use was highest when it was slightly lower than the price of tap water, rather than significantly lower than tap water [21]. Therefore, this study hypothesizes that public perceptions of recycled water prices significantly affect their willingness to use. Based on this, we propose the following hypotheses:H2: 

The perceived price of recycled water negatively influences a consumer’s willingness to purchase recycled water.

As for the quality and risk factors of recycled water, Tortajada and Ong concluded that the primary constraint to the implementation of recycled water reuse projects is due to public concerns about the health hazards and environmental impacts of recycled water reuse [35]. Consumers often perceive recycled products as inferior quality to new conventional products, as well as potentially presenting safety risks [36]. Matsumoto et al. have found that Japanese consumers were less knowledgeable regarding remanufactured vehicles and tended to perceive them as providing lower benefits and higher risks, especially regarding quality risks [37]. Similarly, Ong pointed out that there are still shortcomings in wastewater treatment technologies when dealing with some emerging biological and chemical molecules [38], which may lead to recycled water containing harmful microbial and chemical residues that pose a potential threat to human health and ecology [39]. This this raises public doubts about the desirability of treating wastewater and the quality of recycled water [40]. Based on this, we propose the following hypotheses:H3: 

The perceived quality of recycled water positively affects a consumer’s willingness to purchase recycled water.

H4: 

The perceived risk of recycled water negatively influences a consumer’s willingness to purchase recycled water.

User comments are an essential information source for the public to understand recycled water, as they reflect how others feel about its use. The Elaboration Likelihood Model (ELM) suggests that individuals carefully and systematically analyze the information they receive and consider whether to accept the opinions, thus leading to changes in their attitudes [41]. The information revealed by reviews affects the public decision-making behavior [23]. After viewing user reviews, consumers cognitively process the content of reviews and make subjective judgments about them at a psychological level; this psychological dynamic is the key to determining their final purchase behavior [42]. In other words, consumers will assess the quality of the recycled water through user reviews, then decide whether to purchase it or not. Based on the above, we propose the following hypotheses:H5a: 

User comments indirectly affect consumer purchase intentions by influencing perceived usefulness.

H5b: 

User comments indirectly influence consumer purchase intention by affecting perceived quality.

H5c: 

User comments indirectly affect consumer willingness to purchase by affecting perceived price.

H5d: 

User comments indirectly affect consumer willingness to buy by affecting perceived risk.

Based on the above theoretical background and research hypothesis, we sought to determine the public’s recycled water reuse behavior from the consumers’ perspective (Figure 1). We use eye-movement behavior indicators to measure the public’s willingness to purchase recycled water and select eye-movement gaze indicators as items of user comments to measure their impact on the public’s willingness to purchase recycled water. Further, we measured public perceptions of recycled water using a scale containing the perceived usefulness, perceived price, perceived quality, and perceived risk. 6. Conclusions and Recommendations

The construction of recycled water infrastructure is strategically important to conserve resources, protect the environment, and achieve sustainable socio-economic development. In this study, we conducted an eye-tracking experiment focused on public recycled water purchase behavior to explore the mechanism by which user reviews affect public recycled water reuse behavior by simulating a real purchase scenario. We obtained the following main conclusions: (1) perceived usefulness, perceived quality, and perceived risk all have significant effects on public purchase intentions, with perceived usefulness having the greatest effect; (2) the public is inclined to pay more attention to negative reviews, and user reviews presented the largest moderating effect between perceived usefulness and purchase intention, followed by their moderating effect on perceived risk and purchase intention. Furthermore, user reviews also had a significant moderating effect on perceived price and purchase intention.

Based on the above findings, we propose the following recommendations to improve the public’s willingness to purchase recycled water and promote the construction of recycled water infrastructure: First, we found that perceived usefulness, perceived risk, and perceived quality directly affect the public’s willingness to purchase. Therefore, managers should vigorously promote the current state of water resources and the water environment through various channels to increase the public’s sense of environmental urgency, as well as increase the publicity of the environmental benefits of building recycled water infrastructure and its necessity, to enhance the public’s perceived usefulness of recycled water. At the same time, the quality and safety of recycled water should be guaranteed, and information on recycled water quality standards and production should be disclosed to the public, thus weakening public concerns and aversions regarding recycled water. Companies can also promote experiential activities, such as product trials, which can help consumers to understand the value of recycled water better and weaken their worries and doubts about its quality and safety, thus promoting the public’s willingness to accept it. Second, we observed that user reviews could enhance public willingness to accept by strengthening perceived usefulness. Therefore, managers should encourage users to share their feelings and experiences regarding the use of recycled water, especially positive evaluations of recycled water reuse in the surrounding environment. Again, we found that the public is biased in that they generally pay more attention to negative reviews and that user reviews negatively moderate the relationships between perceived risk, perceived price, and public willingness to purchase. Therefore, production technology should be continuously improved to avoid the health risks associated with recycled water. Managers should strictly regulate the quality of the recycled water while using various media and adopting various forms (e.g., thematic education, knowledge competitions, visits, community consultation, and so on) to disseminate specific and targeted information about recycled water—including quality, quality standards, regulatory systems, and so on—to the public, to alter the negative public perception of recycled water. Reducing negative consumer perceptions of recycled water is expected to have the effect of increasing the public’s willingness to reuse recycled water and promote the construction of recycled water infrastructure.