Enthalpy Change of V-Ti Interface as an Indicator of High Catalytic Activity.

Vanadium-supported TiO2 is one of the most widely used catalysts. In previous reports, most researchers focused on the performance of a formed catalyst and almost no work was devoted to understanding the activation process from a precursor to a catalyst. In this work, differential scanning calorimetry was used to calculate the enthalpy change (ΔH, kJ·mol-1) during the transition from a precursor to a catalyst. When the V-loading amount was increased from 0.1 to 5 wt %, more polymeric V were formed and ΔH of V-supported anatase was decreased from 10.13 to 4.13 kJ·mol-1. At the same loading amount of 1 wt %, anatase showed a higher ΔH value of 8.71 kJ·mol-1 than rutile and brookite. When the ratio of the {001} facet was increased in the anatase, ΔH was increased to 9.65 kJ·mol-1. A theoretical calculation proved that V embedding into {001} facet resulted in a bigger energy difference in comparison to {101} and {100} facets. A bigger ΔH stood for forming a more active V species during catalyst preparation, which further stood for a higher turnover frequency (TOF, s-1) during the catalysis. The anatase with the biggest ratio of the {001} facet resulted in the biggest ΔH as well as the largest TOF. These results help to understand the interaction between loaded active species and catalyst support, which is in favor of designing an effective catalyst.

Degradation and regeneration inhibition of PCDD/Fs in incineration fly ash by low-temperature thermal technology.

Low-temperature thermal degradation of PCDD/Fs for incineration fly ash (IFA), as a novel and emerging technology approach, offers promising features of high degradation efficiency and low energy consumption, presenting enormous potential for application in IFA resource utilization processes. This review summarizes the concentrations, congener distributions, and heterogeneity characteristics of PCDD/Fs in IFA from municipal, medical, and hazardous waste incineration. A comparative analysis of five PCDD/Fs degradation technologies is conducted regarding their characteristics, industrial potential, and applicability. From the perspective of low-temperature degradation mechanisms, pathways to enhance PCDD/Fs degradation efficiency and inhibit their regeneration reactions are discussed in detail. Finally, the challenges to achieve low-temperature degradation of PCDD/Fs for IFA with high-efficiency are prospected. This review seeks to explore new opportunities for the detoxification and resource utilization of IFA by implementing more efficient and viable low-temperature degradation technologies.

Extraction of phosphorus from sewage sludge ash by electrodialysis combined with wet-chemical extraction.

Phosphorus (P) recovery from sewage sludge ash (SSA) is considered to be an effective method for P recovery. In this work, P extraction and the removal of heavy metals were realized by electrodialysis. Low-cost, easily available, and environmentally friendly plant extracts were applied as suspension to reduce the inevitable secondary pollution. And the feasibility of using plant extracts was analysed by comparing with using deionized water (DI) and oxalic acid (OA) solution. When SSA was suspended in different solutions (DI, OA, and three plant extracts - Hovenia acerba (HA), Saponin (SA) and Portulaca oleracea (PO)), the effects of reaction time and plant extract concentration on P extraction and heavy metal separation of SSA under ED treatment were compared. After the process of electrodialysis, compared to other experimental groups, electrodialysis with plant extracts obtained more P released from SSA, but less P migrated to the anode chamber. However, when SSA was suspended in PO at a concentration of 80 g/L, the proportion of P transferred from SSA to the anode chamber can still reached 37.86%. In addition, the use of plant extracts as suspension had a positive effect on the removal of heavy metals, but its effect was lower than that of the oxalic acid-treated experimental group. The results indicated that the use of plant extracts for wet-chemical extraction combined with electrodialysis promoted the removal of heavy metals and the extraction of P from SSA, which is a feasible option.

Enhanced Replenishment of Active Lattice Oxygen Using Chiral Copper Oxide.

Effective catalytic performance of the transition metal oxide is attributed to high specific surface areas, abundant surface oxygen atoms, and balanced valence ratios. Although the chirality of the transition metal has attracted attention, most studies have focused on optical application. A few chiral transition metal oxides were used as electrocatalysts and photocatalysts. The influence of the chiral catalysts on the thermal catalysis process has been less explored. In this study, Mn-loaded chiral (M/l-CuO and M/d-CuO) and achiral CuO (M/a-CuO) were synthesized and compared in the catalytic oxidization of toluene. Spectrally analyzed Mn was well-dispersed on both chiral and achiral CuO. l-CuO and d-CuO showed nanoflower-like chirality. The angles between each (001) plane of CuO were the source of chirality. The toluene turnover frequency (TOF) of the samples was in the order of Mn/d-CuO (5.6 × 10-5 s-1) > Mn/l-CuO (4.4 × 10-5 s-1) > Mn/a-CuO (3.2 × 10-5 s-1) at 240 °C, consistent with the order of the oxygen replenishment rate. The as-prepared catalysts had similar ratios of lattice oxygen/surface adsorbed oxygen, Mn3+/Mn4+, and Cu+/Cu2+. A higher TOF was attributed to chirality, which increased the lattice oxygen replenishment speed from the gaseous phase to the solid surface. Our study indicates gas-solid catalysis from a structure-activity viewpoint.

Carbon tax-driven technological innovation may accelerate the directional recovery of waste cooking oil into bio-jet fuel: An evolutionary game approach.

Biofuel production from waste cooking oil (WCO) offers an alternative to fossil fuels, especially for high-value bio-jet fuel. However, this industry is hindered by informal recyclers who covertly divert large amounts of WCO to illegal gutter oil production. Investigating the dynamic evolution of stakeholder behavior will help explore solutions. Thus, this study presents a tripartite evolutionary game model that includes the government, formal recyclers, and informal recyclers, aims to redesign the government intervention strategy to promote the directional flow of WCO from restaurant trash cans to bio-jet fuel production. We find that the evolutionary game model exists eight possible evolutionary stability strategies (ESSs), and the choice of each ESS depends mainly on the trade-off between costs and revenues for each stakeholder. The numerical study results reveal that formal recyclers are driven to carry out technological innovation by government support, profiting from bio-aviation kerosene products, and income from carbon emission reduction. These factors also have an indirect impact on the transformation of informal recyclers. Therefore, the government should provide adequate support for technological innovation to formal recyclers and increase their profitability of products to enable them to actively implement innovative strategies. This can be achieved by expanding the sales channels of bio-jet fuel products, implementing patent protection measures, and improving the carbon reduction trading mechanism. Furthermore, the government's high tax rate on formal recyclers and the significant profits earned by informal recyclers through illegal gutter oil production may dissuade them from transitioning their businesses. Above findings are in line with the actual issues of WCO recycling and provide a new dynamic decision-making method for enterprises and government managers.

Assessing the wastewater reclaim system consisted of wastewater plant - hybrid constructed wetland - ultra filtration and reverse osmosis in a chemical industrial park, a multi-criteria decision-making analysis.

Wastewater reclaim in industrial parks can effectively reduce the dependence on external water resources, few literatures evaluated the reclaim system from perspectives of economy, technology, and environmental impact. It is very popular across China that a constructed wetland is linked with a wastewater plant and then discharged the tailwater into surface waters, based on current situation, pilot experiment, and other available techniques, six scenarios for wastewater reclaim system were designed for Shanghai Chemical Industrial Park. Using life cycle assessment, it was found that in scenario of pilot experiment, most environmental impact was derived from wastewater plant and ultra filtration - reverse osmosis, in which ultra filtration - reverse osmosis accounted >20 % for POCP, AP, and EP, Wastewater plant accounted >86 % for ADP, ODP. It was showed that electricity and sludge were most important parameters affecting LCA, when electricity consumption was reduced by 20 %, total standardized environmental impact would be changed in the range of 1.40 %-1.65 %, the most significant change was HTP (6.12 %-6.32 %) when 20 % up and downward change in sludge amount, followed by MAETP (5.27 %-5.36 %). A multi-criteria decision-making analysis was conducted on all the scenarios based on environmental impact, life cycle cost, technical efficiency, it was showed that the scenario designed for pilot experiment was the best available technique, which was consisted of wastewater plant, hybrid constructed wetland, ultra-filtration and reverse osmosis, and reused as desalted water. A wastewater reclaim plant is suggested from the result of this paper. It was believed that this study could provide references for construction of wastewater reclaim system in industrial parks of the world.

Preparation of phosphorus containing products by co-incineration of sludge ash and calcium-based additives: Focusing one-step and multi-step method.

Due to the irreplaceable nature of phosphorus (P) in biological growth and the shortage of P rock, it is necessary to recover P from waste, such as sludge ash. P-containing products were prepared using sludge ash and calcium-based additives (CaCO3 and eggshell). In addition, the effects of different incineration methods (one-step method (OSM) and multi-step method (MSM)), additive doses, and incineration temperature on the P content and species in the products were investigated. The results indicated that as the dose of calcium-based additives increased, total P (TP) content in P-containing products reduced, apatite P (AP) content increased, non-apatite P (NAIP) content declined, and P solubility in citric acid content decreased. The amount of AP increased, NAIP reduced, and P solubility in citric acid decreased as the incineration temperature climbed. Although P in P-containing products prepared by OSM and MSM changed in a similar way at different additive doses and temperatures, P-containing products prepared by MSM had at least a 6.1% increase in P solubility in citric acid. Compared with OSM, MSM could save 10% of calcium-based additives when reaching the maximum AP value. Additionally, pure materials were employed to investigate how P species changed during the incineration procedure. The advantage of the MSM-prepared product over the OSM-prepared product may be explained by the high concentration of Ca3(PO4)2 and low concentration of amorphous calcium bound P (Ca-P). Overall, MSM is an effective method to reduce the dose of calcium-based additives and increase the bioavailability of P in P-containing products.

Electroplating wastewater treatment by in-situ formation of organic anions and inorganic anions intercalated layered double hydroxides.

The electroplating wastewater containing various metal ions was treated by adding sodium dodecyl benzene sulfonate (SDBS) and regulating pH value, and the resulting precipitates were characterized by X-ray diffraction (XRD). The results showed that organic anions intercalated layered double hydroxides (OLDHs) and inorganic anions intercalated layered double hydroxides (ILDHs) were in-situ formed to remove heavy metals during the treatment process. In order to reveal the formation mechanism of the precipitates, SDB- intercalated Ni-Fe OLDHs, NO3- intercalated Ni-Fe ILDHs and Fe3+-DBS complexes were synthsized by co-precipitation at various pH values for comparison. These samples were characterized by XRD, Fourier Transform infrared (FTIR), element analysis as well as the aqueous residual concentrations of Ni2+ and Fe3+ were detected. The results showed that OLDHs with good crystal structures can be formed as pH≤7, while ILDHs began to form at pH = 8. When pH < 7, complexes of Fe3+ and organic anions with the ordered layered structure were formed firstly, and then with increase in pH value, Ni2+ inserted into the solid complex and the OLDHs began to form. However, Ni-Fe ILDHs were not formed when pH ≤ 7. The Ksp (Solubility Product Constant) of OLDHs was calculated to be 3.24 × 10-19 and that of ILDHs was 2.98 × 10-18 at pH = 8, which suggested that OLDHs might be easier to form than ILDHs. The formation process of ILDHs and OLDHs were also simulated through MINTEQ software, and the simulation output verified that OLDHs could be easier to form than ILDHs at pH ≤ 7. Information from this study provides a theoretical basis for effective in-situ formation of OLDHs in wastewater treatment.

Megacity's pathway toward sustainable food waste management and its environmental performance in a developing country: Evidence from Shanghai, China.

Due to the far distance impact on resident, aquatic and soil ecosystem health, food waste disposal becomes the focus of municipal waste strategy in developing countries. Shanghai is a leading city in China, its evolution of food waste management can indicate the coming future of the nation. In this city, from 1986 to 2020, the open dumping, landfill and incineration of food waste had been gradually banned, replaced by centralized compost and anaerobic digestion and other recovery ways. This study selected ten scenarios, ever used for food/mixed waste disposal in Shanghai, and analyzed the environmental impact change during the period 1986-2020. Life cycle assessment showed that although the generation of food waste raised rapidly, the total environmental impact, which was dominated by Freshwater Aquatic Ecotoxicity Potential, displayed a sharp decrease as 96.09 %, and Global Warming Potential decreased by 28.14 %. Substantial efforts should be made to improve the collection rate of biogas and landfill gas to reduce environmental impact, and quality of residues from anaerobic digestion and compost plants should be improved and utilized in its legal ways. Driving forces for the goal of sustainable food waste management in Shanghai involved economic development, environmental regulations and the supporting national/local standards.

Quantifying the effect of socio-economic-geo drivers on the change of municipal waste disposal in China by an integrated TWFE-PRF-SDM methodology.

Municipal solid waste management and disposal in China have significantly evolved since 2000. Due to China's vast land area and significant socioeconomic and geographic disparities, nationwide waste management strategies need to be further evaluated. This study quantified the effect of social, economic, and geographic drivers on municipal waste disposal activities in 31 provincial-level administrative regions from 2003 to 2020, by establishing a methodology integrated by two-way fixed effects regression model, panel random forest, and spatial Durbin model. The results showed, in the past two decades, socio-economic-geo indicators significantly co-decided the landfill and incineration activities. In particular, the explanatory ability of GDP per capita was above 45%, while land resources and city size also showed great significance. Spatial autocorrelation analysis showed that the relationship between landfill/incineration rates and socio-economic-geo drivers changed notably from unobvious to significant with economic growth. Furthermore, the local economy and land resources displayed more impact than those of the neighboring regions, while sci-tech and education showed clear spatial spillover effects. Chinese government would carefully assess the full-scale promotion policy of incineration plants, landfill is still hold as a reasonable option for regions with specific socio-economic-geo conditions.

Phosphorus recovery from incinerated sewage sludge ash using electrodialysis coupled with plant extractant enhancement technology.

Phosphorus (P) is an integral mineral nutrient for the growth of plants and animals. As the increasing population worldwide, the demand for P resources keeps increasing. Therefore, it is necessary to recover P from secondary resources. Unlike conventional P recovery processes, this work focused on the recovery of P from incinerated sewage sludge ash (ISSA) using electrodialysis as the main technology coupled with plant extractants. In this study, Amaranthus and hydrolyzed polymaleic anhydride (HPMA) were used as P extractants, investigating the effects of HPMA concentration and pH of the compound agent on the migration of P and heavy metals from ISSA. The results showed that the concentration of HPMA and pH of the compound agent had a significant influence on the mobility of P and heavy metals. Meanwhile, the impacts of eggshell additions and voltage on the recovery efficiency of P was also studied by using waste eggshells as calcium sources. We found that when eggshells were added at 10 g/L and the voltage was 10 V, the recovery efficiency of P reached 96.05%. Moreover, XRD patterns revealed that the mineral phase of recovered P-containing products was predominantly hydroxyapatite, which had good environmental benefits. Generally, the favorable results have been achieved in the recovery efficiency of P and has practical implications for P recovery from ISSA.

Recognizing zeolite topologies for Cu2+ localizations with effective activities for selective catalytic reduction of nitrogen oxide.

Cu-loaded zeolites are widely investigated in selective catalytic reduction of nitrogen oxide, but effects of zeolite topologies on formed active species and the changing tendency remain unexplored. In this work, catalytic turnover frequencies (TOF) of Cu loaded ZSM-5, Beta, MOR, and SSZ-13 were first determined. The topology-localized Cu species in these zeolites were analyzed by temperature-programmed reduction of H2. Then Multiple Linear Regression distinguished TOF contributions (kj, s-1·mol-1) of the Cu species. Density functional theory calculated NH3 dehydrogenation energy of the Cu species. As a result, topologies with more node atoms showed bigger kj and lower dehydrogenation energies simultaneously. The best topology in each zeolite was 10-membered ring (ZSM-5), 6-membered ring facing a 12-membered ring (Beta), 8-membered ring (MOR), and cha cage (SSZ-13). Moreover, cha cage-localized Cu2+ exhibited the largest kj and the lowest dehydrogenation energy among all the Cu species. This work reveals topology-catalysis relationships in the zeolite, which benefits zeolite design for enhanced catalytic performances.

Low-energy production of a monolithic catalyst with MnCu-synergetic enhancement for catalytic oxidation of volatile organic compounds.

Producing a low-cost catalyst by a low-cost method is one of the hottest topics in the field of catalytic oxidization of volatile organic compounds (VOCs). In this work, a catalyst formula with a low-energy requirement was optimized in the powdered state, and verified in the monolithic state. An effective MnCu catalyst was synthesized at a temperature as low as 200 °C. Removals were all bigger than 88% for toluene, ethyl acetate, hexane, formaldehyde, and cyclohexanone at a low temperature of 240 °C. The MnCu catalyst was then loaded on a honeycomb cordierite, which was also effective for toluene removal at 240 °C. After characterizations, active phases were Mn3O4/CuMn2O4 in both the powdered and monolithic catalysts. The enhanced activity was attributed to balanced distributions of low-valence Mn and Cu, as well as abundant surface oxygen vacancies. The obtained catalyst is produced by low energy and effective at low temperature, which suggests a perspective application.

A review on identification, quantification, and transformation of active species in SCR by EPR spectroscopy.

Electron paramagnetic resonance (EPR) is the only technique that provides direct detection of free radicals and samples that contain unpaired electrons. Thus, EPR had an important potential application in the field of selective catalytic reduction of nitrogen oxide (SCR). For the first time, this work reviewed recent developments of EPR in charactering SCR. First, qualitative analysis focused on recognizing Cu, Fe, V, Ti, Mn, and free-radical (oxygen vacancy and superoxide radical) species. Second, quantification of the active species was obtained by a double-integral and calibration method. Third, the active species evolved because of different thermal treatments and redox-thermal processes under reductants (NH3 and NO). The coordination information of the active species in catalysts and their effects on SCR performances were concluded from mechanism viewpoints. Finally, potential perspectives were put forward for EPR developments in characterizing the SCR processes in the future. After all, EPR characterization will help to have a deep understanding of structure-activity relationship in one catalyst.

Cordierite and citric acid regulate crystal structure of manganese oxide for effective selective catalytic reduction of nitrogen oxide.

Catalyst is the key to effective selective catalytic reduction of nitrogen oxide, and developing catalyst is always one of the hottest topics in both field of industry and academy. In order to realize an industrial application, one catalyst must grow on a specific support. However, seldom work compared the difference of catalyst growth with or without support. In this work, Mn2+ growth on cordierite (a typical commercial catalyst support) was investigated. The formed active species were detailedly characterized. As a result, orthorhombic cordierite guided Mn2+ to form orthorhombic oxide (γ-MnO2). In comparison, Mn2+ preferred to form tetragonal ß-MnO2 without the guide of cordierite. During the synthesis, cordierite and citric acid promoted γ-MnO2 dispersion, increased growth of exposed (301) facet, and created lattice distortion between (301) and (101) planes. ß-MnO2 mainly exposed (101) facet. The best catalyst was γ-MnO2, which was mostly dominated by (301) facet and had an obvious lattice distortion from 75° to 78° between (301) and (101) planes. In comparison, 0.1 g of the γ-MnO2 reached a catalytic conversion rate 1.6 times bigger than 1.0 g of ß-MnO2 at 250 °C. This work helps to understand guiding effect of support on formed catalytic species, which is in favor of developing effective commercial catalysts for environmental pollutants.

Footprints in compositions, PCDD/Fs and heavy metals in medical waste fly ash: Large-scale evidence from 17 medical waste thermochemical disposal facilities across China.

Chemical compositions, polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) profiles and heavy metals (HMs) leachability of medical waste fly ash (MWFA) from 17 thermochemical treatment facilities in eight Chinese provinces were first investigated. Large-scale and extended monitoring revealed high chloride and Zn contents and similar PCDD/Fs congener profiles in MWFA. Particularly, the PCDD/Fs and HMs concentrations implied greater toxicity than that observed for municipal solid waste incinerator fly ash (MSWIFA). The maximum international toxic equivalent value of PCDD/Fs in MWFA was 40 times that of MSWIFA, and the leaching concentrations of Zn and Hg were 15 and 4 times those of MSWIFA, respectively. Notably, MWFA characteristics suggest the possibility of recycling and sustainable disposal solutions owing to the high Cl and Zn content with good recovery instead of landfill disposal. Similarities in chemical composition, PCDD/Fs homolog distribution, and water-solubility of chloride salts allows co-processing of MWFA and MSWIFA via water-washing detoxification and thermal treatment, such as that used in cement kilns. This study supplements existing literature on the characteristics and risk management of MWFA.

Garbage-classification policy changes characteristics of municipal-solid-waste fly ash in China.

Policy is a powerful tool determining solid-waste treatment and disposal. In 2019, China carried out the "garbage-classification policy" in 46 cities. So-called dry garbage is then separated from municipal solid waste and treated alone by incineration. This work investigated the influence of the policy on contents and leaching characterizations of municipal solid waste incineration fly ash. Median value of Cl was significantly increased from 17.43 wt% to 28.63 wt%. Median content of CaO maintained a similar value (51.21 wt% and 47.27 wt%). Ten year ago, CaClOH was not generally observed in fly ash. However, this phase was widely detected nowadays. Median value of heavy-metal (Zn, Pb, Cu, Cd, Cr, and Ni) was decreased from 9007.69 mg/kg to 7652.72 mg/kg. Thus, the policy also positively affected hazardous-waste collection. Heavy-metal leaching concentrations were decreased and chemical speciation became more stable because CaClOH supplied more alkalinity and binding ability for heavy metals. Therefore, fly-ash treatment technologies and their running parameters should be regulated to adapt above new characterizations after the garbage-classification policy.

Reveal of free radicals in manganese-based catalysts and their roles during selective catalytic reduction of nitrogen oxide.

HYPOTHESIS: Manganese-based catalysts attract extensive attentions in low-temperature selective catalytic reduction (SCR) of nitrogen oxide (NOx). However, seldom work focuses on the existence of free radicals and their roles in SCR. EXPERIMENTS: In this work, electron paramagnetic resonance spectrometer and density functional theory are combined to reveal surface characterizations of manganese oxide and Ce/La-doped manganese oxides. FINDINGS: As a result, superoxide radical (O2*) exists on manganese-oxide surface, produces nitrogen-containing free radical, and functions as electron transfer between NOx and NH3 at 100 °C, resulting in good NOx conversion as well as N2 selectivity at the same time. The O2* is born of accepting electrons on adsorbed oxygen through overlapped orbits of Mn-d and O-p. Additional metal doping increases the percentage of O2* among all oxygen species from 2.9 % to 6.9 % (Ce doping) and 5.1 % (La doping). The order of O2* percentage is consistent with the NOx-conversion order at 100 °C, i.e., Ce doping (91.6 %) > La doping (55.7 %) > catalyst without doping (27.5 %). Above result helps to understand interface behaviors of manganese-based catalyst in SCR. This work is also in favor of developing more effective low-temperature catalysts.

Accessibility control of Cu sites to enhance adsorption capacity of ultra-low-concentration methyl mercaptan.

Methyl mercaptan (MM) is a typical malodorous gas and low-concentration MM makes human uncomfortable. Adsorption is applied in industry to remove MM. However, adsorptive-site agglomeration results in that adsorbent is not fully utilized. In this work, pore size and unsaturated-site amount of Cu-based metal-organic frameworks (MOFs) were regulated by using different ligands to increase adsorptive-site accessibility for MM. As a result, when Cu2+ sites were imbedded in MOFs network, these sites were inaccessible for MM; when Cu2+ sites were occupied by none-network organics, these sites were accessible for MM after simple activation; when Cu2+ sites were occupied by water, these sites were the most effective for MM removal among above site species. Furthermore, with the increase of bonding sites in ligands, channel pore size of MOFs was increased. Both pore size and unsaturated-site amount were important to MM removal. When above MOFs were used in purification of ultra-low-concentration MM, the regulated MOFs with a big pore size (11 and 5 Å) and water-occupied sites showed a best removal capacity of 160.3 mg g-1. The main result of this work is in favor of understanding structure-efficiency relationship in MOFs. This work also helps to develop effective adsorbents for ultra-low-concentration pollutants.

Mapping the impact of a large municipal waste disposal area on surface water: 1993-2017, case of Laogang, Shanghai.

In China, the impact of waste disposal facilities is always a cause of concern for the government and the public. Laogang Municipal Waste Disposal Area (LMDA), Shanghai, one of the largest municipal waste disposal areas in the world was selected as case in this study, and it was attempted to analyze the changes in the surface water quality, and map the impacted area by LMDA on surrounding streams from its operation period of 1993-2017. The results showed that, during the whole period, only biochemical oxygen demand (BOD5) showed a continuous improvement with a percentage of 85.92%, however, chemical oxygen demand (CODcr), ammonia (NH4+-N) and total phosphorus (TP) significantly improved but BOD5 slightly deteriorated began from 2013. Using spatial analysis tools and Kendall's concordance test, CODcr and phenol at LMDA showed a significant impact on surrounding surface water; especially, the impacted area for CODcr decreased from 106.30 km2 to 22.86 km2 from 1993 to 2017, which dropped from 4.3 to 0.9 times the area of LMDA. Surprisingly, NH4+-N and TP at LMDA were affected by the surrounding streams, instead of having an impact on them. Interestingly, heavy metals and non-metals such as Hg, As, Zn, and Se in the surrounding streams were unlikely affected by LMDA. The driving forces for surface water quality improvement included the eco-remediation of closed unsanitary landfills, upgrade in waste shipping and terminals, operation of sanitary landfills and incineration plants for landfill diversion. Capsule: Impacted area of municipal waste disposal area is not so large.