Mechanistic impact of organics on electro-induced transformation of iron oxides and simultaneous uranium immobilization in wastewater.

The incorporation of uranium into the magnetite generated through via electrochemical methods represents a sustainable strategy for remediation of uranium-contaminated organic wastewater. Nevertheless, the influence mechanisms of organics on this treatment process remain insufficiently understood. This study used an electrochemical system featuring iron and graphite electrodes along with sodium chloride as the electrolyte to investigate the impact of various organics on uranium removal.

Facilitated uranium and organic removal and electricity production via a zinc oxide/carbon felt cathode equipped hybrid tandem photocatalytic fuel cell.

The combined pollution by uranium and organic matter has posed a serious challenge in the treatment of radioactive wastewater, while traditional treatment methods suffered from the problems of poor treatment efficiency and difficult recycling. Therefore, this study developed a novel hybrid tandem photocatalytic fuel cell (HTPFC) system which decorated with a ZnO modified carbon felt (ZnO/CF) cathode. This HTPFC not only efficiently removed UO and organic matter while generating electricity, but can also be quickly disassembled and reassembled.

Booming microplastics generation in landfill: An exponential evolution process under temporal pattern.

Landfills are the main plastic sinks and microplastics (MPs) sources in the anthropogenic terrestrial system. Understanding the dynamic process of generating MPs is a prerequisite to reducing their potential risk, which remains unexplored because of the complex stabilization process of landfills. In this study, we investigated the evolution process of MPs generated in a partitioned landfill, with well-recorded disposal ages of over 30 years.

Big disparities in CH emission patterns from landfills between the United States and China and their behind driving forces.

Waste is the bridge linking resource consumption and greenhouse gas generation, and waste landfills are the main anthropogenic source of methane (CH). The United States (US)-China Joint Glasgow Declaration and the Global Methane Pledge are committed to reducing tractable CH emissions; however, differences between the involved countries as well as their generation forecast processes have hampered cooperation. In this study, we provide a deep insight into CH emissions from municipal solid waste (MSW) landfills and identify the disparities in CH emissions with local socio-economic conditions.

Environmental impacts and nutrient distribution routes for food waste separated disposal on large-scale anaerobic digestion/ composting plants.

Centralized biological treatments, i.e., anaerobic digestion (AD) and in-vessel composting (IVC), were supposed to be the promising processes for the disposal of food waste (FW) after source separation, while the systematic benefits were unclear for FW with high water content, salt and oil and thus influenced the selection by the local decision-makers.

Chemical and olfactive impacts of organic matters on odor emission patterns from the simulated construction and demolition waste landfills.

The explosive increase of construction and demolition waste (CDW) caused the insufficient source separation and emergency disposal at domestic waste landfills in many developing countries. Some organic fractions were introduced to the CDW landfill process and resulted in serious odor pollution. To comprehensively explore the impacts of organic matters on odor emission patterns, five CDW landfills (OIL), with organic matters/ inert CDW components (O/I) from 5% to 30%, and the control group only with inert components (IL) or organics (OL) were simulated at the laboratory.

Living alone, social cohesion, and quality of life among older adults in rural and urban China: a conditional process analysis.

Objectives: To test the independent and combined impact of social cohesion and geographic locale (urban/rural) on quality of life (QoL) for older adults in China. Using conditional process analysis, we tested three hypotheses: (1) QoL will be lower for persons living alone than those who live with family; (2) social cohesion will mediate the association of living arrangement and QoL; and (3) geographic locale will moderate direct and indirect pathways in the mediation model.

Design: Cross-sectional data from WHO Study on Global Aging and Adult Health (SAGE) (China, Wave 1, 2007-2010).

Occurrence of banned and commonly used pesticide residues in concentrated leachate: Implications for ecological risk assessment.

Amounts of banned and current pesticides have been used in domestic and agricultural pest control, and their residues have accumulated along the waste stream. In this work, pesticides were characterized in concentrated leachates (CLs) from 5 municipal landfill sites, 2 incineration plants and 1 composting plant in six provinces. A total of 31 pesticides were detected which included 8 organochlorine pesticides (OCPs, 303-2974 ng/L), 16 organophosphorus pesticides (OPPs, 1380-13,274 ng/L) and 7 synthetic pyrethroids (SPs, 319-5636 ng/L).

Improved understanding of dissolved organic matter transformation in concentrated leachate induced by hydroxyl radicals and reactive chlorine species.

Concentrated leachate (CL) is commonly featured with high salt and dissolved organic matters (DOM). In this study, molecular transformation of DOM was revealed to identify the reactive mechanisms with (non-) radical reactive species in ozonation, electrolysis and E-ozonation processes. Chlorine ions were efficiently activated into non-radical reactive chlorine species (RCS) with 245.

Molecular insight into variations of dissolved organic matters in leachates along China's largest A/O-MBR-NF process to improve the removal efficiency.

Dissolved organic matter (DOM) is a critical component of high-strength organic wastewater, and the study of them from molecular perspective could improve the removal efficiency. Leachate samples were collected from China's largest two stage anaerobic/aerobic membrane bioreactor and nanofiltration (A/O-MBR-NF) process, with the treatment capacity of 5000 t/d, and characterized by electrospray ionization (ESI) coupled with Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) from molecular perspective. High molecular weight (m/z > 500) compounds with 40-50 carbon atoms and 15-20 double bond equivalence (DBE) were biodegraded into medium molecular weight compounds with 10-20 carbon atoms and ∼10 DBE.

Variations and environmental impacts of odor emissions along the waste stream.

Odor nuisance related to municipal solid waste (MSW) disposal is one of the main incentives to counter the Not-In-My-Backyard Syndrome. Moreover, integrated odor management contributes to specific odor control at different waste treatment stages. In this study, odor emissions along typical MSW streams were categorized based on their olfactive and environmental impacts after a field investigation of the residential district (RD), transfer station (TS), and landfill (LF) in the Chongming Eco-island.

Ex situ simultaneous nitrification-denitrification and in situ denitrification process for the treatment of landfill leachates.

The objective of this research was to investigate the ex situ simultaneous nitrification-denitrification (SND) and in situ denitrification process and to evaluate its application for treating landfill leachates at long-term operations. Based on the predicted contaminant concentrations, two sets of laboratory-scale bioreactor landfill systems (an ex situ nitrification and in situ denitrification bioreactor as well as an ex situ SND and in situ denitrification bioreactor) were operated continuously for about 48 weeks. The recirculated leachate quantity and effluent characteristics of leachates were regularly monitored and analyzed by using the standard method.

The identification and health risk assessment of odor emissions from waste landfilling and composting.

Odor nuisance is the main incentive for Not In My Back Yard campaigns around municipal solid waste (MSW) waste disposal facilities, and the odor identification is of significance for the understanding of the odor properties from MSW with different disposal methods. In this study, odor emissions from different stages at two large-scale working MSW disposal facilities, i.e.

Use of bioreactor landfill for nitrogen removal to enhance methane production through ex situ simultaneous nitrification-denitrification and in situ denitrification.

High concentrations of nitrate-nitrogen (NO-N) derived from ex situ nitrification phase can inhibit methane production during ex situ nitrification and in situ denitrification bioreactor landfill. A combined process comprised of ex situ simultaneous nitrification-denitrification (SND) in an aged refuse bioreactor (ARB) and in situ denitrification in a fresh refuse bioreactor (FRB) was conducted to reduce the negative effect of high concentrationsof NO-N. Ex situ SND can be achieved because NO-N concentration can be reduced and the removal rate of ammonium-nitrogen (NH-N) remains largely unchanged when the ventilation rate of ARB-A2 is controlled.

The typical MSW odorants identification and the spatial odorants distribution in a large-scale transfer station.

Odorants from municipal solid waste (MSW) were complex variable, and the screening of key offensive odorants was the prerequisite for odor control process. In this study, spatial odor emissions and environmental impacts were investigated based on a large-scale working waste transfer station (LSWTS) using waste container system, and a comprehensive odor characterization method was developed and applied in terms of the odor concentration (OC), theory odor concentration (TOC), total chemical concentration (TCC), and electric nose (EN). The detected odor concentration ranged from 14 to 28 (dimensionless), and MSW container showed the highest OC value of 28, EN of 78, and TCC of 35 (ppm) due to the accumulation of leachate and residual MSW.

Effect of low aeration rate on simultaneous nitrification and denitrification in an intermittent aeration aged refuse bioreactor treating leachate.

Three intermittent aeration aged refuse bioreactors (ARBs), A, B, and C, with aeration rates of 670, 1340, and 2010L/m aged refuse·d in stage 1, and 670, 503, and 335L/m aged refuse·d in stage 2 were constructed to evaluate the effect of low aeration rate on leachate treatment by simultaneous nitrification and denitrification (SND). Results show that SND can be achieved and improved by reasonably adjusting the aeration rate of the ARB. In stage 1, the average chemical oxygen demand (COD) removal rates of ARBs A, B, and C were 91%, 92%, and 93%, respectively.