An Integrated Natural System for Leachate Treatment

The performance of a bench scale upflow sludge bed (USB) denitrifying reactor was evaluated in order to integrate it into a C and N removal system for Sanitary Landfill Leachate. The raw leachate used presented COD and NH4-N average values of 30000 mg/l and 1000 mg/l, respectively. The complete system comprises in addition an UASB reactor and a nitrifying RBC. A portion of the aerobic reactor effluent was recycled into the denitrification stage and some raw leachate was also added as an additional C source. In order to obtain operating parameters the denitrifying reactor was operated alone. Sludge from an aerobic reactor (RBC) treating raw leachate was used as inoculum. Shortly after the start up, good granulation of the sludge bed was observed. Using raw leachate and UASB outlet as carbon sources with COD/NO3-N ratios of 4 and 12, respectively, denitrification efficiencies of about 90% were reached. A sludge yield of 0.16 gVSS/gCODremoved was obtained operating with raw leachate. For the anoxic reactor operating in the complete system, denitrification efficiencies of 90% were also achieved. A nitrogen gas recycle was a successful way to avoid frequently observed sludge bed rising problems.

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Volcanic RocksPrinciples of the Natural System of Volcanic Rocks.F. Baron Richtofen

The American Naturalist ◽

10.1086/270219 ◽

1868 ◽

Vol 2 (4) ◽

pp. 205-207

Keyword(s):

Natural System

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Engineering design of landfill leachate treatment system in a waste incineration plant in Chengdu

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/621/1/012111 ◽

2021 ◽

Vol 621 ◽

pp. 012111

Author(s):

Li Ke ◽

Wang Fang ◽

Yu Zuoming ◽

Lu Xinsheng

Keyword(s):

Engineering Design ◽

Landfill Leachate ◽

Waste Incineration ◽

Treatment System ◽

Leachate Treatment ◽

Incineration Plant

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Application of Electrocoagulation with a New Steel-Swarf-Based Electrode for the Removal of Heavy Metals and Total Coliforms from Sanitary Landfill Leachate

Applied Sciences ◽

10.3390/app11115009 ◽

2021 ◽

Vol 11 (11) ◽

pp. 5009

Author(s):

Mayk Teles de Oliveira ◽

Ieda Maria Sapateiro Torres ◽

Humberto Ruggeri ◽

Paulo Scalize ◽

Antonio Albuquerque ◽

...

Keyword(s):

Heavy Metals ◽

Landfill Leachate ◽

Lower Cost ◽

Sanitary Landfill ◽

Leachate Treatment ◽

Removal Of Heavy Metals ◽

Waste Characteristics ◽

Electrode Passivation ◽

Steel Swarf ◽

Sanitary Landfill Leachate

Sanitary landfill leachate (LL) composition varies according to climate variables variation, solid waste characteristics and composition, and landfill age. Leachate treatment is essentially carried out trough biological and physicochemical processes, which have showed variability in efficiency and appear a costly solution for the management authorities. Electrocoagulation (EC) seems a suitable solution for leachate treatment taking into account the characteristics of the liquor. One of the problems of EC is the electrode passivation, which affects the longevity of the process. One solution to this problem could be the replacement of the electrode by one made of recyclable material, which would make it possible to change it frequently and at a lower cost. The objective of the present work was to evaluate the removal of heavy metals (As, Ba, Cd, Cr, Cu, Fe, Pb, Mn, Ni, Se and Zn) and coliforms from a LL by EC using electrodes made from steel swarf (SfE) up to 8 h. Removal efficiencies of detected heavy metals were 51%(Cr), 59%(As), 71%(Cd), 72%(Zn), 92%(Ba), 95%(Ni) and >99%(Pb). The microbial load of coliforms in leachate was reduced from 10.76 × 104 CFU/mL (raw leachate) to less than 1 CFU/mL (after treatment with SfE) (i.e., approximately 100% reduction). The use of SfE in EC of LL is very effective in removing heavy metals and coliforms and can be used as alternative treatment solution for such effluents.

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Sustainability Evaluation on the Grain to Green Program in the Hexi Corridor of China: A Metacoupled System Perspective

Sustainability ◽

10.3390/su13031498 ◽

2021 ◽

Vol 13 (3) ◽

pp. 1498

Author(s):

Jian Zhang ◽

Tao Tian ◽

Jinying Cui ◽

Gordon M. Hickey ◽

Rui Zhou ◽

...

Keyword(s):

Hexi Corridor ◽

Gansu Province ◽

Natural System ◽

Ecological Benefits ◽

System Perspective ◽

The Social ◽

Economic Transformations ◽

Labor Transfer ◽

Ancient Silk Road ◽

First Time

Most previous studies aim to predict ecosystem sustainability from the perspective of a sole human or natural system and have frequently failed to achieve their desired outcome. Based on the coupled human and natural system (CHANS) and its interaction with other systems, we attempted to analyze the effectiveness of the Grain to Green Program and predict future trends in the Hexi Corridor, the hub of the ancient silk road of China. At different scales, we applied a metacoupling framework to investigate the flows, effects, and causes of the complex CHANS. Three typical inner river watersheds within the corridor at three different geographic scales (local, regional and national) were estimated and compared. The Telecoupling Geo App, additional models, and software tools were employed to evaluate the CHANS series of the focal system (Hexi Corridor, local), adjacent system (Gansu Province, regional), and distant system (China, national). The results showed that most flows can be screened and quantitatively analyzed across focal, adjacent and distant systems. The social and economic transformations in adjacent and distant systems could affect the possibility and whereabouts of labor transfer in the focal system. Moreover, the labor migration increased the implementation efficiency of the Grain to Green Program as a Payment for Ecosystem Services (PES) strategy, thereby improving its ecological benefits. For the first time, we established a metacoupled model to quantitatively evaluate aspects of ecosystem sustainability in China, providing insight to the theory and application of sustainability science.

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