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Large amounts of microplastics can accumulate in wastewater treatment plants (WWTPs), and sludge disposal is suspected to be a major source of microplastics pollution in the environment. It is therefore important to investigate the distribution of microplastics in the sludge of each processing unit of WWTPs. However, little information is available on this topic in China. Accordingly, in this study, the abundance and characteristics of microplastics in the sludge of two WWTPs in Chengdu were investigated. The abundance of microplastics in the sludge samples ranged from 44.4 n·kg−1 to 750.0 n·kg−1. Microplastics were mainly divided into particles (32.16%), debris (28.14%) and fibers (17.08%) according to their shape, and the colors of the microplastics were mainly green (35.19%) and translucent (18.06%). The particle sizes were mainly larger than 1 mm in dimension. Polyethylene, polypropylene and polystyrene were the prevalent types of microplastics analyzed. Our results provide basic information for better understanding the characteristics of microplastics in sludge and for improving sludge treatment. [Display omitted] • MPs in sludges of two typical CASS process WWTPs in Chengdu has been investigated. • Polyethylene, polypropylene and polystyrene were the most common compositions of MPs. • The abundances of MPs in the sludge samples ranged from 44.4 to 750.0 n·kg−1. • About 68.35% of MPs have a particle size greater than 1 mm. [ABSTRACT FROM AUTHOR]

[Display omitted] • Novel MM–TCMRs were synthesized for concurrent removal of phosphate and ammonium. • MM–TCMRs exhibits excellent phosphate and ammonium adsorption capacity. • Potential phosphate and ammonium removal mechanism with MM–TCMRs was proposed. • >70 % phosphate and ammonium were recovered from swine wastewater after four cycles. • Nutrient–loaded MM–TCMRs is applied as a fertilizer to promote alfalfa growth. Magnetic magnesium (Mg)–loaded Chinese herbal medicine residues (MM–TCMRs) were fabricated to simultaneously remove and recover phosphate and ammonium from wastewater. The MM–TCMRs exhibited larger specific surfaces and rougher structures with massive spherical particles than those of original residues. They could be separated by adjusting the magnetic field. The phosphate and ammonium adsorption by MM–TCMRs were matched with the pseudo–second–order model, while the Langmuir model yielded the maximum adsorption capacities of 635.35 and 615.57 mg g−1, respectively. Struvite precipitation on the MM–TCMRs surface was the primary removal mechanism with electrostatic attraction, ligand exchange, intra–particle diffusion, and ion exchange also involved. The recyclability of MM–TCMRs confirmed their good structural stability. More importantly, the nutrient–loaded MM–TCMRs enhanced alfalfa growth and improved soil fertility in planting experiments. Collectively, the MM–TCMRs are promising candidates for nutrient removal and recovery from wastewater. [ABSTRACT FROM AUTHOR]

In order to mitigate the harmful effects of eutrophication in water bodies, the applications of lanthanum-modified materials for phosphate removal from wastewater have attracted much attention. Unlike conventional adsorbents, plant wastes usually have poor adsorption abilities and are difficult to be reused for desorption of phosphate due to their small pore sizes and ununiform loading of modified ions. In this paper, a composite adsorbent (LC-MM) was synthesized by hydrothermal treatment of waste traditional Chinese medical materials (MMs) with load of lanthanum carbonate and co-heating treatment with coal fly ash (CFA), which was applied to remove phosphate from water. The results showed that maximum adsorption capacity of LC-MM was 52 mg g−1, and the LC-MM showed appreciable adsorption capacity of phosphate for agricultural wastewater in the presence of complex interfering ions and for urban surface waters with low phosphate concentrations. Five adsorption-desorption cycles showed good reusability. The mechanism study showed that the La3+ ions were more uniformly distributed on the surface of the absorbents with the introduction of Fe3+, Al3+, Mg2+ and Ca2+ ions in CFA. The ligand exchange between phosphate and carbonate, the internal spherical complexation formed by lanthanum ion and phosphate, and surface chemical precipitation attachment are the main reasons why the adsorption capacity of LC-MM approached or even surpassed that of conventional lanthanum-modified adsorbents. In conclusions, this work proposed an effective method for the modification of plant materials. [Display omitted] • Reuse of two types of waste after treatment. • A method to improve the inefficiency of phosphate adsorption by plant materials. • The mechanism of modification is to influence the state of lanthanum on the surface of the carrier. • Effect of phosphate separated after adsorption on plant growth. [ABSTRACT FROM AUTHOR]

In order to mitigate the harmful effects of eutrophication in water bodies, the applications of lanthanum-modified materials for phosphate removal from wastewater have attracted much attention. Unlike conventional adsorbents, plant wastes usually have poor adsorption abilities and are difficult to be reused for desorption of phosphate due to their small pore sizes and ununiform loading of modified ions. In this paper, a composite adsorbent (LC-MM) was synthesized by hydrothermal treatment of waste traditional Chinese medical materials (MMs) with load of lanthanum carbonate and co-heating treatment with coal fly ash (CFA), which was applied to remove phosphate from water. The results showed that maximum adsorption capacity of LC-MM was 52 mg g−1, and the LC-MM showed appreciable adsorption capacity of phosphate for agricultural wastewater in the presence of complex interfering ions and for urban surface waters with low phosphate concentrations. Five adsorption-desorption cycles showed good reusability. The mechanism study showed that the La3+ ions were more uniformly distributed on the surface of the absorbents with the introduction of Fe3+, Al3+, Mg2+ and Ca2+ ions in CFA. The ligand exchange between phosphate and carbonate, the internal spherical complexation formed by lanthanum ion and phosphate, and surface chemical precipitation attachment are the main reasons why the adsorption capacity of LC-MM approached or even surpassed that of conventional lanthanum-modified adsorbents. In conclusions, this work proposed an effective method for the modification of plant materials. [Display omitted] • Reuse of two types of waste after treatment. • A method to improve the inefficiency of phosphate adsorption by plant materials. • The mechanism of modification is to influence the state of lanthanum on the surface of the carrier. • Effect of phosphate separated after adsorption on plant growth. [ABSTRACT FROM AUTHOR]

One important pathway for human exposure to per- and polyfluorinated alkyl substances (PFASs) is based on the Earth's atmosphere. Figuring out atmospheric transformation mechanism of PFASs is beneficial for understanding their effects on humans. However, the focus on the molecular-level transformation mechanism of emerging PFASs in the atmosphere still need to be improved. In this work, we used quantum chemistry calculation to study ·OH-initiated degradation mechanism of a new fluorinated alcohol (C 3 F 7 OCHFCF 2 SCH 2 CH 2 OH, abbreviated FESOH) in the presence of oxygen and nitric oxide. Three main conformers of FESOH share the similar initial mechanism that the abstraction reactions of H atom at α-C and β-C atoms are the main pathways (activation free energies of <10 kcal mol−1 at 298 K), but make different contributions to the whole FESOH degradation. Subsequent transformations starting from initial products at α-C atoms will reunite with that at β-C atoms, and the intermediate (C 3 F 7 OCHFCF 2 S·) is produced. After O 2 addition to the intermediate and the following SO 2 elimination, the alkyl radical (C 3 F 7 OCHFCF 2 ·) can undergo consecutive chain cleavage cycles to form CF 3 OH finally. The bioaccumulation evaluation shows that FESOH and its transformation products cannot be accumulated in organisms. The work is helpful for knowing the atmospheric fate of FESOH at molecular level and can provide some insight into the transformation of other PFASs in the atmosphere. [Display omitted] • Three main conformers of FESOH account for approximate 99% of all conformers. • The H-abstraction at α-C and β-C mainly occurs for ·OH-initiated FESOH degradation. • Subsequent reactions can form alkyl peroxynitrite, fluorinated aldehyde and CF 3 OH. • FESOH and its transformation products cannot be accumulated in organisms. [ABSTRACT FROM AUTHOR]

The disposal of electroplating sludge (ES) is a common concern of researchers. Currently, it is difficult to achieve effective fixation of heavy metals (HMs) using traditional ES treatment. As green and effective HMs removal agents, ionic liquids can be used for the disposal of ES. In this study, 1-butyl-3-methyl-imidazole hydrogen sulphate ([Bmim]HSO 4) and 1-propyl sulphonic acid-3-methyl imidazole hydrogen sulphate ([PrSO 3 Hmim]HSO 4) were used as washing solvents for the removal of Cr, Ni, and Cu from ES. In reaction with increased agent concentration, solid–liquid ratio, and duration, the amount of HMs eliminated from ES rises, whereas opposite patterns were shown in response to rising pH. The quadratic orthogonal regression optimisation analysis also revealed that the ideal washing specifications for [Bmim]HSO 4 were 60 g L−1, 1:40, and 60 min, respectively, for agent concentration, solid–liquid ratio, and washing time, while those for [PrSO 3 Hmim]HSO 4 were 60 g L−1, 1:35, and 60 min, respectively. Under the optimal experimental conditions, the Cr, Ni, and Cu removal efficiencies for [Bmim]HSO 4 were 84.3, 78.6, and 89.7%, respectively, and those values for [PrSO 3 Hmim]HSO 4 were 99.8, 90.1, and 91.3%, respectively. This was mainly attributed to that ionic liquids enhance metal desorption through acid solubilisation, chelation, and electrostatic attraction. Overall, ionic liquids are reliable washing reagents for ES contaminated by HMs. [Display omitted] • Ionic liquids exhibited efficient Cr, Ni and Cu removal from electroplating sludge. • Effect of various experimental conditions on heavy metals removal was explored. • Removal mechanism of ionic liquids to heavy metals was described. • The finding will provide new ideas for the disposal of electroplating sludge. [ABSTRACT FROM AUTHOR]

Hydrometallurgy is the main method to regenerate valuable metals from electroplating sludge and reduce its environmental hazards. As a key step to efficiently recover metals, it is important to choose an environmentally friendly and efficient leaching agent. In this work, four green ionic liquid (ILs) ([BMIm]HSO 4 , [HOOCMIm]HSO 4 , [BSO 3 HMIm]HSO 4 , and [BSO 3 ]Py.HSO 4) were used to leach copper from copper–rich electroplating sludge (C–ES). The tested ILs could effectively leach copper from C–ES, but functionalized ILs have better leaching efficiency, especially sulfonate ILs, which could remove 100% of Cu from C–ES under optimal conditions. Kinetics studies showed that the leaching process of controlled by chemical reaction and material diffusion, and the apparent activation energies were 39.21, 0.98, 14.47, and 41.93 kJ mol−1, respectively. Introducing functional groups (such as carboxyl and sulfonate group) which can complex with metals on cations can enhance the H+ release and complexation ability of ILs, improve the mass transfer efficiency between liquid–solid phase, and thus improve the copper leaching ability by ILs. These findings are of great significance for selecting functional ILs to efficiently regenerate copper and the resource utilization from C–ES. [Display omitted] • An efficient leaching method of copper from electroplating sludge is proposed. • The leaching behavior and the leaching mechanism of copper in ILs was analysed. • Functionalized ILs had better hydrogen release and metal complexation ability. • Sulfonate functionalized ILs is most conducive to copper recovery from C-ES. [ABSTRACT FROM AUTHOR]

There remains a need to develop efficient and recoverable washing reagents to repair heavy metal-contaminated soil. However, the past study of recovery only considered conventional chelating agents, hindering the sustainable development of new reagents. In this study, two new-reagents, organic phosphonic acid (DTPMPA) and polycarboxylic acid (AA/AMPS/HPA), simultaneously investigated their ability to remove heavy metal and recover by electrochemical to improve reagent sustainability. Results indicated that the metal removals were influenced by the washing solution concentrations, pH, and contact time. The maximum removal by DTPMPA was 72% Cd and 33% Zn, were higher than those of AA/AMPS/HPA (concentration, 5%; pH, 3.0; and contact time, 120 min). The strong chelation of the phosphonic acid group of DTPMPA binds more metal ions. Characterization results demonstrated that both reagents were successfully recovered using electrochemical methods. While AA/AMPS/HPA had a better recovery performance because of electrostatic adsorption interactions with the metal ions, the rewashing ability of Cd and Zn was 88% and 64% of the fresh solution. Moreover, in benefit analysis, AA/AMPS/HPA showed better circular economy and long-term sustainability properties. Therefore, AA/AMPS/HPA is a feasible remediation reagents of the heavy-metal-contaminated soil with both efficiency and sustainability. The development of reagent takes into account efficiency and reuseable simultaneously, showing great economic benefits. • Soil washing by organic phosphonic acid and polycarboxylic acid were tested. • Reagent concentration, pH, washing time, and recyclability were investigated. • DTPMPA removed metals in the soil by the chelation of the phosphonic acid group. • Cd and Zn removal efficiencies from contaminated soil were high. • Polycarboxylic acid showed better circular economy and long-term sustainability. [ABSTRACT FROM AUTHOR]

The cost–effective removal and recovery of phosphate from wastewater is of great importance to controlling eutrophication and alleviating the phosphorus resource exhaustion crisis. Herein, chitosan (Cs) encapsulated bimetallic lanthanum (La) and iron (Fe) metal(hydro) oxides (La/Fe–Cs) composites were fabricated using a co–precipitated method for enhanced phosphate removal and recovery. The La/Fe–Cs composites had rough and raised spongy–like surfaces coated with La/Fe (hydr)oxide particles with a high specific surface area of 109.84 m2 g−1, providing more potential binding sites for phosphate capture. The La/Fe–Cs composites with a 1:2 La–to–Fe molar ratio exhibited a maximum adsorption capacity of 67.52 mg g−1 for phosphate at 308 K, calculated using the Langmuir model, which was 211% higher than that of monometallic Fe–Cs composites. Meanwhile, this composite also showed a high phosphate removal rate (63–95%) in an extensive applicable pH range (3.00–10.00) and rapid adsorption within 10 min (up to 94%). Moreover, the adsorption of phosphate by La/Fe–Cs composites was mildly disturbed against co–existing ions of NO 3 −, Cl−, and humic acid, while adsorption capacities were reduced by almost 13–45% with the existence of SO 4 2−, HCO 3 −, and CO 3 2−. The FTIR, XPS, and DFT results suggested that La–doped facilitated phosphate removal and the predominant mechanisms involved electrostatic interaction, surface precipitation, and inner–sphere complexation processes. Additionally, La/Fe–Cs composites also illustrated excellent efficiencies in simultaneous scavenging phosphate and ammonia from eutrophication and poultry wastewater. These results highlight bimetallic La/Fe–Cs composites are promising candidates for efficient elimination and recovery of phosphate from real wastewater, and subsequently could be used as slow–release fertilizers or soil amendments. [Display omitted] •Bimetallic La/Fe–Cs composites were synthesized for phosphate removal. • The derived bimetallic La/Fe–Cs composites showed excellent phosphate adsorption capacity of 67.52 mg g−1 • Mechanisms driving phosphates adsorbed onto the La/Fe–Cs composites were elucidated by FTIR, XPS, and DFT. • High efficiency in scavenging phosphate from eutrophication wastewater and poultry wastewater. • The phosphate–loden La/Fe–Cs composites can be used as slow–release fertilizers or soil amendments. [ABSTRACT FROM AUTHOR]

The cost–effective removal and recovery of phosphate from wastewater is of great importance to controlling eutrophication and alleviating the phosphorus resource exhaustion crisis. Herein, chitosan (Cs) encapsulated bimetallic lanthanum (La) and iron (Fe) metal(hydro) oxides (La/Fe–Cs) composites were fabricated using a co–precipitated method for enhanced phosphate removal and recovery. The La/Fe–Cs composites had rough and raised spongy–like surfaces coated with La/Fe (hydr)oxide particles with a high specific surface area of 109.84 m2 g−1, providing more potential binding sites for phosphate capture. The La/Fe–Cs composites with a 1:2 La–to–Fe molar ratio exhibited a maximum adsorption capacity of 67.52 mg g−1 for phosphate at 308 K, calculated using the Langmuir model, which was 211% higher than that of monometallic Fe–Cs composites. Meanwhile, this composite also showed a high phosphate removal rate (63–95%) in an extensive applicable pH range (3.00–10.00) and rapid adsorption within 10 min (up to 94%). Moreover, the adsorption of phosphate by La/Fe–Cs composites was mildly disturbed against co–existing ions of NO 3 −, Cl−, and humic acid, while adsorption capacities were reduced by almost 13–45% with the existence of SO 4 2−, HCO 3 −, and CO 3 2−. The FTIR, XPS, and DFT results suggested that La–doped facilitated phosphate removal and the predominant mechanisms involved electrostatic interaction, surface precipitation, and inner–sphere complexation processes. Additionally, La/Fe–Cs composites also illustrated excellent efficiencies in simultaneous scavenging phosphate and ammonia from eutrophication and poultry wastewater. These results highlight bimetallic La/Fe–Cs composites are promising candidates for efficient elimination and recovery of phosphate from real wastewater, and subsequently could be used as slow–release fertilizers or soil amendments. [Display omitted] •Bimetallic La/Fe–Cs composites were synthesized for phosphate removal. • The derived bimetallic La/Fe–Cs composites showed excellent phosphate adsorption capacity of 67.52 mg g−1 • Mechanisms driving phosphates adsorbed onto the La/Fe–Cs composites were elucidated by FTIR, XPS, and DFT. • High efficiency in scavenging phosphate from eutrophication wastewater and poultry wastewater. • The phosphate–loden La/Fe–Cs composites can be used as slow–release fertilizers or soil amendments. [ABSTRACT FROM AUTHOR]

[Display omitted] • Evaluating ecological civilization construction trends of China during 2003–2020. • Chinese ecological civilization level has been moderately enhanced. • Main obstacles are conflict between Human and nature and psychological imbalance. • Specific factors lie in high resource intensity and hysteretic social management. Ecological civilization (EC), firstly put forward by the Chinese government, has attracted extensive attention in the world. However, how to evaluate progress of ECC (Ecological civilization construction) still needs deep exploration. To this end, this study put forward one set of novel indicator system to trace progress of ECC through considering environmental contribution in terms of emergy, composed of DPE (Degree of physiological equilibrium), DPB (Degree of psychological balance), DBHE (Degree of balance between human and the environment), DHD (Degree of human development), HDEE (Harmony degree of economy and the environment) and ECI (Ecological civilization index). Then these indicators were used to explore trends of Chinese ECC during 2003–2020. Results show that (1) DPE falls by 4.21%, (2) DPB declines by 90.19%, (3) DBHE decreases by 73.80%, (4) DHD increases by 5.36 times, and (5) HDEE climbs by 2.91 times during this study period. Generally Chinese EC level rises by 1.11 times, driven by human development and improved relationship between economy and the environment. Main obstacles come from conflict between human and the environment, followed by psychological imbalance. Therefore, China's government should further promote harmony between human and the environment and improve individual psychological state in the future. [ABSTRACT FROM AUTHOR]

HRPG (Heat recovery power generation) is widely adopted in the cement industry. However, the measure's impacts on the environmental and economic performance of this industry are not completely clear due to the extra resources inputs. To this end, this research implemented an emergy evaluation through considering emissions' impacts, to investigate impacts of HRPG on environmental performance of this industry. Meanwhile, a supplementary economic evaluation was done to explore changes of its economic performance before and after implementing HRPG. One cement enterprise with the two scenarios (Scenario 1 with HRPG vs. Scenario 2 without HRPG), as a case study, was investigated using the presented approach. It is found that (1) HRPG reduces total resources consumption by 1.13%, and raises share of renewable resources by 2.28%; (2) HRPG reduces dependence degree of this enterprise on imported resources and its wealth loss by 1.93% and 1.13% respectively; (3) HRPG enhances wastes recycling rate and energy efficiency by 329.44 times and 6.91% respectively; (4) HRPG enhances emergy yield rate by 0.89%, cuts environmental load rate by 1.77%, and improves environmental sustainability by 2.71%; (5) pollutant emissions' impacts reduce emergy yield rate by 9.48–9.56%, raise environmental rate by 0.02%, and weaken environmental sustainability by 9.50–9.59% (6) HRPG improves economic benefit of this enterprise by 22.24%, which roots in reduced electricity expense. Generally implementation of HRPG achieves energy-saving, emissions reduction and improvement of economic benefit, which well explains why this measure is widely adopted in cement industry. However, this measure is limited to improve environmental performance of this enterprise due to high dependence on nonrenewable resources, and it still has relatively lower energy efficiency than the updated one. Finally this study proposes some targeted suggestions to deal with these issues in the future. Image 1 • Effect of heat recovery power generation (HRPG) on cement production was explored. • HRPG raises energy efficiency and reduces dust emissions' impact. • HRPG has limited contribution to improvement of its environmental performance. • HRPG clearly improves its economic benefit. • Adjustment of its resources structure and update of HRPG should be emphasized. [ABSTRACT FROM AUTHOR]