Daoping Peng

Southwest Jiaotong University · Faculty of Geosciences and Environmental Engineering

Nitrogen (N) and phosphorus (P) are primary pollutants contributing to water quality degradation and eutro­ phication but are also indispensable resources for agricultural production. In this study, we synthesized porous MgO/Mg(OH)2-modified starch gels (SC-M/SC-OM) to facilitate the simultaneous removal of N and P from wastewater and address the c...

This study investigated the influences of polymer types, polymer loadings, and preparation methods on the hydraulic conductivity of polymer-enhanced bentonite geosynthetic clay liners (EB GCLs) to coal gangue leachate (CL). Sodium carboxymethylcellulose (CMC) and xanthan gum(XG) were selected to modify the sodium-bentonite GCLs (Na-B GCLs), with a...

In recent years, the ecological safety issues of red mud tailings ponds have been frequent, with problems such as the seepage damage of anti-seepage materials at the bottom of tailings ponds, failure of anti-seepage systems, and leakage of pollutants. In order to deeply analyze the influence of red mud (RM) leachate on the microstructure of the mod...

A study was conducted to investigate the multi-scale pore structure-based mechanism controlling the hydraulic conductivity of polymer-enhanced geosynthetic clay liners (GCLs) prepared by the wet-mixed method to bauxite liquors (BLS and BLA). The multi-scale pore structures were evaluated using MIP and N2GA tests quantitatively. Conventional GCL per...

Although anaerobic digestion is a promising way for valorization of waste activated sludge, the process severely deteriorates the sludge dewaterability. Herein, a novel strategy of iron and nitrogen co-doped biochar (Fe-N-BC) activated peroxydisulfate (PDS) was developed to improve anaerobically digested sludge (ADS) dewaterability. Results showed...

This study investigated the influences of polymer types (Super Absorbent Polymer, SAP and Polyanionic Cellulose, PAC), preparation methods (dry-mixed, dry-sprinkled, or wet-mixed), initial polymer loadings (1.0%, 2.5%, 5.0%, 10.0%, and 15.0%), and bauxite liquors (synthetic bauxite liquor, BLS and actual bauxite liquor, BLA) on the polymer elution...

https://www.elsevier.com/books/managing-mining-and-minerals-processing-wastes/qi/978-0-323-91283-9

Recently, phosphorus recovery as vivianite (Fe3(PO4)2⋅8H2O) from anaerobic digestion of waste-activated sludge (WAS) has attracted increasing attention because of its high recovery efficiency and economic value. However, the relatively small crystal size restricts the separation and recovery of vivianite. In this study, magnetic biochar (MB) was pr...

Bisulfate (BS) has recently attracted increasing attention as a green alternative to persulfates (PS) in sulfate radicals based advanced oxidation processes (SR-AOPs). Moreover, facile fabrication of zero-valent iron (ZVI) biochar composites and disposal of red mud remain challenges. Herein, ZVI biochar was synthesized from red mud (RM) and ginkgo...

The struvite method has been widely used to recover N and P from wastewater. However, the drawbacks of alkali consumption and small crystallization are not negligible. Therefore, alkaline porous carrier materials are greatly desired to enhance struvite crystalline precipitation and maintain suitable pH values. In this study, using red mud (RM) as a...

In this study, red mud (RM) was used as a support for LaFeO 3 to prepare LaFeO 3 -RM via the ultrasonic-assisted sol–gel method for the removal of methylene blue (MB) assisted with bisulfite (BS) in the aqueous solution. Characterization by scanning electron microscopy and the Brunauer–Emmett–Teller method indicated that LaFeO 3 -RM exhibited a lar...

Red-mud leachate from tailings ponds contains Cr(VI), which can pollute groundwater via infiltration through anti-seepage layers. This paper investigates leachate from a red-mud tailings pond in southwest China and the red clay in the surrounding area to simulate the adsorption of Cr(VI) onto clay at different pHs, using geochemical equilibrium sof...

During tunnel construction in strongly developed karst terrain, water inrush hazards often occur due to the complex hydrogeological conditions, which require accurate prediction of water inflow. In this study, a dynamic modeling approach for water inflow prediction of karst tunnels using the conduit flow process (CFP) is developed that considers bo...

In this study, red mud modified by manganese dioxide(MRM) was utilized as an adsorbent to effectively remove Cd ²⁺ from aqueous solution. The characteristics were analysed by SEM–EDS, XRD, BET, FTIR and XPS. Different factors that affected the Cd ²⁺ removal on MRM, such as dosage, initial pH, initial Cd ²⁺ concentration, were investigated using bat...

To treat high-concentration wastewater while realizing the utilization of red mud as a resource. The modified red mud composite material (MgO-RM) was prepared through the red mud loaded with magnesium oxide for efficient simultaneous recovery of nitrogen and phosphorus in wastewater. The effects of the initial pH, the mass ratio of nitrogen to phos...

In semi-continuous anaerobic digestion, organic material feed sometimes may not be consumed completely in one day and it may considerably help to increase biogas production of next day. Such occurrence is called ’biogas accumulation phenomenon’, which cannot reflect the real biogas production from next day’s feed. In this test, first-order model wa...

Three commercially available bentonite-polymer composite geosynthetic clay liners (BPC GCLs) were selected for hydraulic conductivity testing, respectively permeated by two types of bauxite leachates with high alkalinity (pH > 12) and high ionic strength (620.3 mM). The influence of BPC GCLs on the attenuation behavior of Cr/Pb in the bauxite leach...

The high ionic strength of the porewater in red mud (bauxite liquor from digestion) can suppress swelling of montmorillonite, resulting in geosynthetic clay liners (GCLs) that are too permeable to be effective as liners in red mud disposal facilities. Bentonite-polymer composite GCLs (BPC GCLs) have been developed as more resilient lining materials...

Co-digestion of sewage sludge with food waste is a beneficial pathway for sewage plants to enhance their biogas yield. This paper employs hybrid programming with system dynamics simulation to optimize such a co-digestion system from the perspective of demand-oriented biogas supply chain, thus to improve the efficiency of the biogas utilization. The...

In our study, five kinds of red mud samples from different aluminum factories were collected for sequencing batch leaching experiments to simulate the leaching behavior of rare metals of red mud in natural storage conditions under different pH. The results showed that the leaching rates of La, Sc, and Y decreased with the increase of pH, reached 45...

This paper explores the feasibility of flexible biogas production by co-digestion of food waste and sewage sludge based on experiments and mathematical modeling. First, laboratory-scale experiments were carried out in variable operating conditions in terms of organic loading rate and feeding frequency to the digester. It is demonstrated that biogas...

This study constructs a community carbon emission assessment system based on the greenhouse gas emissions inventory of the Intergovernmental Panel on Climate Change (IPCC). The system contains three activities, namely, building service, transport, and waste treatment and disposal. A street community in Ya'an, Sichuan, China is taken as a typical ca...

In order to study the impact of pH on leaching characteristics of toxic elements from red mud (RM), heavy metals (Pb, As, Cr) and F- were investigated in this paper. HNO3-HClO4-HF-HCl digestion test was conducted to investigate the content of chosen heavy metals in RM. A pre-test was performed first to get the predicted acid/base addition quantity,...

This study analyzes the leaching behavior of elements from red mud (bauxite residue) at pH values ranging from 2 to 13. The leaching characteristics of metals and contaminated anions in five red mud samples produced by Bayer and combined processes were analyzed using the batch leaching technique following the US Environmental Protection Agency (USE...

A nationwide investigation was carried out to evaluate the geochemical characteristics and environmental impacts of red mud and leachates from the major alumina plants in China. The chemical and mineralogical compositions of red mud were investigated, and major, minor, and trace elements in the leachates were analyzed. The mineral and chemical comp...

Red mud (AKA, bauxite residual) is the insoluble residue of bauxite after processing for aluminum oxide (Al2O3). Each year, about 60 million tons of red mud are released worldwide, in which about 6 million tons (~10%) are produced China. The red mud is required to be managed in the reservoir, and make part of the alkali recovery and utilization by...

Straw are always open combusted by farmers, which results in air pollution and strictly harm to health. Fortunately, straw are currently adopted as biomass energy resources which could avoid the risks of open burning. However, ash-related problems of straw in combustion generate troublesome issues because of low sintering temperature. This study ai...

Biomass energy has been used for decades in lieu of fossil fuels. However, biomass, such as wheat straw, typically contains a high concentration of alkali elements, which is likely to induce unfavorable conditions during combustion, such as slagging, agglomeration, and corrosion in the boiler. This study investigated the effects of leaching on the...

The crystalline biofilms formed by Proteus mirabilis on Foley catheters can block the flow of urine from the bladder and cause serious complications in the care of many patients undergoing long-term bladder catheterization. We employed a novel approach to investigate the microstructure of catheter encrustations caused by P. mirabilis. Synchrotron-b...

Synchrotron-based high resolution X-ray microtomography was used to characterize arsenic (As) deposits within porous media. The distribution of arsenic was determined using difference tomography, where the X-rays used to image the sample were selected to be just above and below the As absorption edge at 11,853 eV. The difference tomograms have back...