Since renewable energy has the paramount importance of achieving environmental sustainability, developing countries like Pakistan have been facing numerous renewable energy generation (REG) development challenges. Thus, the REG development in any country can be attributed to its crucial drivers as well as crucial barriers. This work aims to identify crucial influence factors of REG development by conducting multi-facet content analysis as well as partial least square–based structural equation modeling analysis on data collected through a questionnaire survey. It has been conducted based on academicians from four Pakistani universities as well as professionals from Islamabad Electric Supply Company. The key outcomes are as follows: First, through multi-facet content analysis, ten crucial influence factors are identified. Among those factors, lack of good governance, renewable energy adaptation, and governmental energy policies are revealed to be the crucial barriers to REG development, whereas endowed resources, power production approach, renewable energy demand, investment environment for renewable energy projects, economic returns of renewable energy projects, environmental effects, and public acceptance are found to be the crucial drivers of REG development. Based on relative significance, the lack of good governance is unveiled to be the most significant factor, while environmental effects is found to be the least significant one. Moreover, among the drivers of REG development, public acceptance is found to be the prime contributor. At the same time, among crucial barriers, lack of good governance has shown the largest contribution to REG development.

Determine the main factors affecting carbon emissions of the Chinese steel industry is indispensable commitments to achieve the sustainable development of China. Hereby, based on the Stochastic Impacts by Regression on Population, Affluence and Technology (STIPRAT) model, this paper combines the economic growth function, carbon emission production function, and the FDI function of the Chinese steel industry, and uses the three-stage least square equation model (3SLS) to analyze the relationship between China’s economic growth, carbon emissions in the steel industry, and FDI (foreign direct investment) inflows. The results document a complete two-way causal relationship of three variables in the whole country and the Western region, while the relationship in the Eastern region and the Central region is not complete. Moreover, there are no bidirectional causal relationship between carbon emissions and FDI in the Eastern region, while only bidirectional causality between carbon emissions and FDI in the Central region. These findings are of great significance for the Chinese steel industry to formulate effective emission reduction policies.

The current study investigated the efficiency of poly ferric chloride (PFC) and poly titanium tetrachloride (PTC) in coagulation-flocculation process for treatment of paper and cardboard wastewater. The effect of pH (5–11), coagulant concentrations (100–1000 mg/L), mixing rate (10–60 rpm), mixing time (5–25 min), and settling time (5–30 min) were examined. The results showed that the removal efficiency for turbidity, total suspended solids (TSS), and chemical oxygen demand (COD) by PFC and PTC coagulants increased with pH rising up to 9 for the former and 7 for the latter coagulant. Furthermore, the removal efficiency for the afore-mentioned parameters increased along with a 30 rpm increase in the mixing rate, while the mixing time reached 20 min. It was also found that the best removal efficiencies for turbidity, TSS, and COD by PFC under optimal conditions (pH 9, coagulant dose 800 mg/L, and settling time of 25 min) were 97.11%, 99.1%, and 84.91%, respectively. In addition, the removal efficiencies for PTC (optimal conditions of pH 7, coagulant dose 600 mg/L, and settling time of 15 min) were found to be 98.29%, 99.29%, and 86.42%, respectively. Water recovery and the produced sludge volume by PFC were 80% and 200 cm³, respectively, in the settling time of 25 min and for PTC were 81.5% and 185 cm³, respectively, in the settling time of 15 min. Costs of the coagulation-flocculation process for treatment 1 m³ of paper and cardboard wastewater using PTC and PFC were 0.42 $ and 0.32 $, respectively. Finally, it can be concluded that compared to PFC, PTC with higher settling rate has a greater efficiency for treatment of paper and cardboard wastewater.

Two novel adsorbents (LDH@GO-NH₂ and LDH@GO-SH) were successfully synthesized by grafting thiol- or amino-functionalized GO onto LDH and their adsorption capacities for heavy metal ions (Cu(II) and Cd(II)) were significantly enhanced. Characterization experiments illustrated that the thiol group (–SH) or amino group (–NH₂) was grafted onto LDH@GO-NH₂ or LDH@GO-SH. Adsorption isotherms were satisfactorily fitted by both Langmuir and Freundlich models. The maximum adsorption capacity of Cd(II) on LDH@GO-SH at 308 K was 102.77 mg/g, which was about triple that of LDH@GO-NH₂. The enhancement in adsorption capacity of LDH@GO-SH was due to the cooperative effect of LDH and GO-SH. The kinetic experimental data for LDH@GO-NH₂ and LDH@GO-SH were found to be in good agreement with the pseudo-second-order model. The thermodynamic parameters calculated from the temperature-dependent adsorption isotherms indicated that the adsorption was spontaneous and an endothermic process. The possible adsorption mechanisms comprising formation of precipitation, isomorphic substitution of Mg(II), and formation of complexation with amino groups or thiol groups were proposed. Desorption experiments put into evidence that LDH@GO-NH₂ and LDH@GO-SH may be promising suitable candidates for the remediation of metal ions from aqueous solutions in real work in the near future.

Correctly understanding and handling the relationship between economic development and environment protection is an eternal subject for human society. Based on the panel data of 31 provincial administrative units in China from 2000 to 2013, this study used Normalized Difference Vegetation Index (NDVI) and Night-Time Light data to characterize the effect of ecological restoration practices and economic development, respectively, and made an empirical study on the impact of ecological restoration on economic development by means of trend analysis, panel regression model, and subsample analysis. The results showed that the spatial distribution of Night-Time Light was high in the east and low in the west, and the NDVI in the northwest of the Hu Line was generally low, while the southeast was higher. During the 14 years from 2000 to 2013, the overall vegetation coverage showed an upward trend, and the area with stable night lights accounted for the largest proportion. The influence of NDVI on Night-Time Light presented an inverted U-shaped relationship, which meant that the negative influence of the former on the latter was not an inevitable result but its periodic performance. In the process of economic development, there was an optimal value of vegetation coverage. The increase in vegetation coverage had a negative impact on the economic development of the eastern region, but it was beneficial to the central and western regions. In the future, the government should strengthen protection and restoration of ecosystem, promote high-level protection of environment and high-quality development with efficient environmental and economic policies, and differentiate the relationship between development and ecology in the eastern, central, and western regions.

Polycyclic aromatic hydrocarbons (PAHs), as a class of important environmental pollutants, have received considerable concern due to their widespread existence and biological toxicity. The main purpose of this study was to determine concentrations, spatial distribution, possible sources, and potential health risk of PAHs in urban road dust in Shanghai, China. The concentration of Σ₂₆PAHs ranged from 53.0 to 28,700 ng g⁻¹ in road dust samples from Shanghai, which is at the low to medium level compared with other areas around the world. PAHs with 4–5 rings were predominant components in road dust. The level of PAHs in road dust was significantly higher than those in soil and river sediment in Shanghai. Six possible sources of PAHs were apportioned by PMF model. The contribution of pyrogenic PAHs accounted for 91.3% of the total PAHs in road dusts. The motor vehicular emission, natural gas, and coal combustion were main sources for urban road dust PAHs from Shanghai. Four dibenzopyrene (DBP) isomers were contributed averagely 75% of total TEQBₐP concentration. DBalP, BaP, DBaiP, BbF, and DBA were main contributors to total carcinogenic potency, which totally contributed from 69.6 to 91.8% (median 89.1%) to total TEQBₐP in urban road dusts of Shanghai. The results of incremental lifetime carcinogenic risk (ILCR) assessment showed that the total risk values exposed to 24 PAHs in road dust were lower than 10⁻⁴ at all sampling sites, indicating that exposure to dust-bound PAHs at present level was unlikely to result in high carcinogenic risk for both children and adults in Shanghai.

Bus transport has been an important mode taking up a significant share of urban travel demand and thus the corresponding impacts on the environment are of great concerns. Use of driving cycles to evaluate the environmental impacts of buses has attracted much attention in recent years worldwide. The franchised bus service is currently playing important roles in the public transport system in Hong Kong; however, there is no driving cycle developed specifically for them. A set of bus driving cycle was therefore developed using a bottom-up approach where driving data on the bus network with mixed characteristics were collected. Using the Ward’s method for clustering, the collected data were then categorized into three clusters representing distinct franchised bus route patterns in Hong Kong. Driving cycles were then developed for each route pattern including (i) congested urban routes with closely spaced bus stops and traffic junctions; (ii) inter-district routes containing a number of stop-and-go activities and a significant portion of smoother high speed driving; and (iii) early morning express routes and mid-night routes connecting remote residential areas and urban areas. These cycles highlighted the unique low-speed and aggressive driving characteristics of bus transport in Hong Kong with frequent stop-and-go activities. The findings from this study would definitely be helpful in assessing the exhaust emissions, fuel consumptions as well as energy consumptions of bus transport. The bottom-up clustering approach adopted in this study would also be useful in identifying specific driving patterns based on vehicle speed trip data with mixed driving characteristics. It is believed that this approach is especially suitable for assessing fixed route public transport modes with mixed driving characteristics.

Non-human animals serve as sentinels for numerous issues affecting humans, including exposure to toxic heavy metals like lead. Lead plays a role in perpetuating cycles of poverty in low-income communities due to the inequitable distributions of indoor health risks from lower-quality housing and outdoor health risks from industry and polluters, compounded by inequitable distributions of heath care and education. In this pilot study, we explore the potential for studying lead in low-income populations by partnering with nonprofit veterinary outreach programs. We investigate the lead concentration in fur samples of 85 domestic cats (Felis catus) presented to a high-volume spay/neuter clinic and report a mean of 0.723 μg of lead per gram of fur. This study reveals new information about lead exposure in cats in the USA, including that females had greater lead exposure than males, lead exposure increased with increasing amount of access to the outdoors, and lead exposure increased in cats with decreased body condition. We propose that pet, feral, and free-roaming cats presented to high-volume spay/neuter clinics could serve as a source of data about lead exposure in disadvantaged communities where these clinics already operate. Such a non-invasive surveillance system using inert, unobtrusively obtained samples could be deployed to detect highly exposed cats, prompting to follow up contact to a cat’s caretakers to recommend seeking lead testing for themselves, their families, and their neighbors.

Coal mining provides energy to support the development of society. However, mining affects the environment. Thus, substantial attention has been placed on environmental change in mining areas. Research assessing the environmental change in arid and semiarid mining areas has mainly been conducted by analyzing the variation in a single factor. However, the impact of coal mining on the environment is manifold, and there is no comprehensive assessment method. In this paper, we used a remote sensing index referred to as the comprehensive evaluation index (CEI) to comprehensively assess the environmental changes in arid and semiarid mining areas. The CEI in this study was calculated by integrating the changes in vegetation coverage (VC), land surface temperature (LST), and soil moisture (SM) using long time-series Landsat images. The Shendong mining area located in Northwest China was the study area. The results indicate that the environment of the Shendong mining area improved overall from 2000 to 2018. Environmentally degraded areas accounted for approximately 7.59% of the mining area and were concentrated in areas damaged by coal mining.

Multilayer graphene oxide (mGO) was synthesized and functionalized via co-precipitation method to produce magnetic Fe₃O₄-functionalized multilayer graphene oxide nanocomposite (MmGO). Photocatalytic properties of MmGO were investigated in the photodegradation of raw textile wastewater samples. Fourier-transformed infrared spectroscopy revealed Fe–O vibrations, characterized by the band shift from 636.27 to 587.25 cm⁻¹ on MmGO. X-ray diffraction confirmed the successful oxidation of graphite by the (002) peak at 10° and indicated the presence of Fe₃O₄ on MmGO surface by the peaks at 2θ 35.8° (311), 42.71° (400), 54.09° (511), and 62.8° (440). There was no detection of coercivity field and remnant magnetization, evidencing a material with superparamagnetic properties. Then, the textile effluent was treated by heterogeneous photo-Fenton (HPF) reaction. A 2² factorial design was conducted to evaluate the effects of MmGO dosage and H₂O₂ concentration on HPF, with color and turbidity removal as response variables. The kinetic behavior of the adsorption and HPF processes was investigated separately, in which, the equilibrium was reached within 60 and 120 min, for adsorption and HPF, respectively. Pseudo-second-order model exhibited the best fit, with COD uptake capacity at equilibrium of 4094.94 mg g⁻¹, for chemical oxygen demand. The modeling of kinetics data showed that the Chan and Chu model was the most representative for HPF, with initial removal rate of 95.52 min⁻¹. The removal of organic matter was 76.36% greater than that reached by conventional treatment at textile mills. The presence of Fe₃O₄ nanoparticles attached to MmGO surface was responsible for the increase of electron mobility and the enhancement of its photocatalytic properties. Finally, MmGO presented low phytotoxic to Cucumis sativus L. with a RGI of 0.53. These results bring satisfactory perspectives regarding further employment, on large scale, of MmGO as nanocatalyst of textile pollutants.