Anaerobic digestion (AD) is a sustainable wastewater treatment technology which facilitates energy, nutrient, and water recovery from organic wastes. The agricultural and industrial wastes are suitable substrates for the AD, as they contain a high level of biodegradable compounds. The aim of this study was to examine the AD of three different concentrations of phenol (100, 200, and 300 mg/L) containing wastewater with and without co-substrate (acetate) at four different temperatures (25, 35, 45, and 55 °C) to produce methane (CH₄)-enriched biogas. It was observed that the chemical oxygen demand (COD) and phenol removal efficiencies of up to 76% and 72%, respectively, were achieved. The CH₄ generation was found higher in anaerobic batch reactors (ABRs) using acetate as co-substrate, with the highest yield of 189.1 μL CH₄ from 500 μL sample injected, obtained using 200 mg/L of phenol at 35 °C. The results revealed that the performance of ABR in terms of degradation efficiency, COD removal, and biogas generation was highest at 35 °C followed by 55, 45, and 25 °C indicating 35 °C to be the optimum temperature for AD of phenolic wastewater with maximum energy recovery. Scanning electron microscopy (SEM) revealed that the morphology of the anaerobic sludge depends greatly on the temperature at which the system is maintained which in turn affects the performance and degradation of toxic contaminants like phenol. It was observed that the anaerobic sludge maintained at 35 °C showed uniform channels leading to higher permeability through enhanced mass transfer to achieve higher degradation rates. However, the denser sludge as in the case of 55 °C showed lesser permeability leading to limited transfer and thus reduced treatment. Quantitative real-time PCR (qPCR) analysis revealed a more noteworthy change in the population of the microbial communities due to temperature than the presence of phenol with the methanogens being the dominating species at 35 °C. The findings suggest that the planned operation of the ABR could be a promising choice for CH₄-enriched biogas and COD removal from phenolic wastewater.

Globally, a large number of school-aged children is suffering from water-borne diseases, particularly in low-income countries. Arsenic (As) is a hazardous and potentially carcinogenic metal(loid) in drinking water. Nowadays, alarming levels of As have been reported in the groundwater of Vehari District, Punjab Pakistan. In this study, drinking water supplies for high and higher secondary schools were examined in Vehari District. A total of 164 water samples were collected from schools and subjected to heavy metal(loid) analysis (As) and basic water physicochemical parameters. The results were analyzed with respect to sampling area, school type, school education level, sources of sample collection, and the depth of the source. The results revealed that As concentration of water samples in boys’ and girls’ schools was 12.8 μg/L and 9.2 μg/L, respectively. However, when the As concentration in drinking water was evaluated at the school education level, a notable higher concentration of As was observed in the higher secondary schools than the high schools with an average of 19.5 and 9.7 μg/L, respectively. The risk assessment indices were calculated based on education level and different age groups of the children (primary, elementary, high, and higher secondary). High carcinogenic (cancer risk = 0.001) and non-carcinogenic (hazard quotient = 2.0) risks were noted for the children in higher secondary school. The current findings anticipated that the drinking water of schools in Vehari District did not meet the requirement of the World Health Organization (WHO) drinking water quality guidelines. Safe drinking water is crucial for the development and growth of children. Therefore, it is important for educational authorities to take steps for provision of As free safe drinking water to students and local inhabitants.

Due to the environmental impact associated with the products’ use, sustainable design has extended consideration of products’ production to consumption. This study puts forward the concept of sustainable design for users (SDfUs). Using related keywords of sustainable design and user-centered design, we identify a total of 447 usable articles published during 1992–2019 from Scopus. Results of bibliometric analysis show that the number of SDfUs articles has generally continuously increased since 2007. The most productive scholars are from the USA, the UK, and China, while the top three organizations are Loughborough University, Norwegian University of Science and Technology, and Delft University of Technology. Different focuses of SDfUs appear among developed and developing countries. Green building design has emerged as one key area that uses the concept of SDfUs in developed countries such as the USA and the UK. SDfUs studies in developing countries such as China focus on design for end-of-life products’ treatment and disposal. Most SDfUs studies examine how design can contribute to environmental performance through emission reduction and energy saving during products’ use, and articles in one of five clusters from co-word analysis explore users’ behaviors for sustainable design in the textile industry. This paper is the first study that systematically reviews the literature on SDfUs. It provides valuable insights for scholars in the SDfUs-related fields to identify their research directions and partners. Results on clusters from network analysis also offer practical implications for enterprises to learn from the construction and textile industries.

The increasing concern about the environmental issue and its serious adverse effects on human health has made China’s industrial green transformation being a matter of public concern. In this study, a network slack-based measure (NSBM) was applied to explore China’s industrial green development level from the perspective of environmental welfare efficiency (EWE), considering not only the impact of industrial development on environment and economy, but also the impact on human well-being. Based on the data of 30 provincial administrative regions in China from 2004 to 2017, the comprehensive efficiency (CE) of China’s industrial sector was measured and decomposed. The results show that the industrial production efficiency (IPE) is much higher than the EWE, and the improvement of the EWE will be the key to realize the green transformation of China’s industry. On this basis, considering the effects of spatial interaction, the spatial Durbin model was established to analyze the driving factors of EWE. Finally, this research puts forward promotion path of industrial green development.

This study establishes a long-run relationship between ecological footprint, financial development, energy utilization, and tourism in 20 highest emitting economies under the environmental Kuznets curve (EKC) framework by utilizing the longitudinal data covering the period from 1995 to 2017. In the procedure of panel data estimation, conventional methodologies usually overlook the problem of cross-sectional dependence and heterogeneity across cross-sections. The other concern linked to the published literature is that only a small number of studies have estimated the effect of financial development and tourism on the environment in the presence of EKC framework simultaneously, even though these sectors have potentially substantial impact on environmental quality. To bridge these analyzed gaps, this study employs two different unit root tests: Cross-section Augmented Dickey Fuller (CADF) and Cross-section Augmented Im, Pesaran and Shin (CIPS) to confirm that the series are stationary at first difference after confirming the cross-sectional dependency. Westerlund cointegration test applied to confirm the long-run association among variables. Augmented mean group (AMG) results discovered that financial development and the energy utilization significantly enhance the pollution level, while tourism sector reduces the environmental deficit. Moreover, these findings do not validate the EKC hypothesis. Based on the empirical findings, multiple policy implications are suggested to control and reduce the environmental degradation without hindering economic growth and development for the underlying highest emitting countries.

Carbon dioxide (CO₂) and methane (CH₄) are the two major greenhouse gases (GHGs) in the atmosphere that contribute to global warming. Vehicle emissions on expressways cannot be neglected in the megacity Shanghai because oil accounts for 41% of the total primary energy consumption, and the expressway network carries 60% of the total traffic volume. The spatial distributions of CO₂ and CH₄ concentrations were monitored in situ on the expressways and in road tunnels using a mobile vehicle. The average CO₂ and CH₄ concentrations were 472.88 ± 34.48 ppm and 2033 ± 54 ppb on the expressways and 1308.92 ± 767.48 ppm and 2182 ± 112 ppb in the road tunnels in Shanghai, respectively. The highest CO₂ and CH₄ concentrations appeared on the Yan’an Elevated Road and the North-South Elevated Road, respectively, while their lowest values both occurred on the Huaxia Elevated Road passing through the suburban area. The hotspots of CO₂ and CH₄ were not consistent, suggesting that they have different sources. Tunnels had a “push-pull effect” on GHGs, and the traffic-congested Yan’an East Road Tunnel showed a dramatically increasing trend of GHG concentration from the entrance to the exit. This traffic-congested tunnel could accumulate a very high concentration of GHGs as well as other pollutants, which could introduce unhealthy conditions for both drivers and passengers. Significant correlations between CO₂ and CH₄ mostly appeared on the expressways and in the tunnels in Shanghai, suggesting the influences of vehicle exhaust. ΔCH₄/ΔCO₂ (the slope of the linear regression between CH₄ and CO₂) and the CH₄/CO₂ ratio could be used as indicators of vehicle exhaust sources because it increases from sources (e.g., road tunnels) to the observatories in the urban area.

To understand the characteristics of bacterial viability and diversity in landscape waters replenished with reclaimed water, the typical landscape lake using reclaimed water was investigated in this study. Samples were collected from a reclaimed water inlet (P1), a reclaimed water distribution outlet (P2), and a landscape lake replenished by reclaimed water (P3). By means of measuring adenosine triphosphate (ATP), flow cytometry (FCM), and 16S rRNA gene high-throughput sequencing, the bacterial viability and diversity in reclaimed water distribution system and landscape lake were illustrated. The bacterial ATP contents at P1, P2, and P3 were 3.55 ± 1.79 ng/L, 3.31 ± 1.43 ng/L, and 18.97 ± 6.39 μg/L, and the intact bacterial cell concentrations were 5.91 ± 0.52 × 10⁴ cells/mL, 7.95 ± 2.58 × 10⁴ cells/mL, and 5.65 ± 2.10 × 10⁶ cells/mL, respectively. These results indicated a significant increase of bacterial viability in the landscape lake. The Shannon diversity index of 6.535, 7.05, and 6.886 at P1, P2, and P3, respectively, demonstrated no notable change of bacterial diversity from reclaimed water distribution system to landscape lake. However, the relative abundance of Pseudomonas sp. at P3 was significantly higher than that at P1. These findings indicated that viable but non-culturable (VBNC) bacteria could be revived in the landscape lake. The bacterial viability during reclaimed water reuse should deserve special attention.

In this paper, three different designs of a hybrid PV/T double-pass finned plate solar air heater (DPFPSAH) are investigated. The PV module is used to produce electricity needed to run the pump and blow the air into the solar collector. In the first design, the PV module is placed on the absorber plate of the air heater. In the second design, the PV module is placed beside the glass cover of the air heater; while, in the third one, the PV module is completely separated from the solar collector. The effects of mass flow rate of air, flow, and fan pumping powers are studied. The top losses of the third design are found to be higher than that of the first and the second designs by average values of 7.5% and 29%, respectively. The third design of the hybrid systems has the highest overall performance. The daily thermal efficiencies of the first, second, and third designs of the hybrid systems are obtained as 53%, 27%, and 64%, respectively, at mass flow rate of 0.02 kg/s.

Human activities during each phase of coal mine life cycle greatly affect groundwater environment. The groundwater environment destruction is not just only the destruction of underground structure but also the social problems caused by available groundwater resources reduction, as well as the environmental problems affecting ecosystem and human health. Moreover, the groundwater environmental risk of coal mining is complex, dynamic, and long-term. Therefore, a framework and quantitative method for groundwater environmental risk analysis at different phases of the mine life cycle was presented, which is composed of the groundwater system destruction risk (GSDR) and social-economic-ecological vulnerability (SEEV) assessment. The framework was applied in Hongshan abandoned coal mine, North China. Based on the aquifer structure destruction, groundwater flow field evolution, contamination, and social-economic influence analysis, 12 main controlling factors for the GSDR and 7 factors for the SEEV were determined and quantified separately. The results showed that the groundwater contamination of the Hongshan mine mainly occurred after closure, caused by the cross-strata pollution of mine water, which significantly reduced the groundwater available resources, which greatly affected local social-economy sustainable development and residents’ health. The Hongshan mine closure increased groundwater environmental risk, with the GSDR high-risk zone being 12.51 km² larger than that during the mining phase and the SEEV was calculated at a high level. This framework promotes systematic integration of the groundwater environmental risk assessment in mine life cycle.

The agriculture and manufacturing sectors are the backbones of the Indonesian economy; for this reason, research on the effects of these sectors on carbon emissions is an important subject. This work adds urbanization to enrich research on the Environmental Kuznets Curve (EKC) in Indonesia. The results of this study indicate that the EKC hypothesis was confirmed in Indonesia with a turning point of 2057.89 USD/capita. The research results show that all variables affect the escalation of greenhouse gas emissions in Indonesia. Furthermore, there is a bidirectional causality relationship between emissions with economic growth, emissions with agricultural sector, emissions with manufacturing sector, economic growth with agricultural sector, and economic growth with manufacturing. The unidirectional causality is found in emissions by urbanization and economic growth by urbanization. To reduce the impact of environmental damage caused by the activities of agriculture, manufacturing, and urbanization sectors, it is recommended that the government conduct water-efficient rice cultivation and increase the use of renewable energy.