scholarly journals Comparative environmental sustainability study of an improved sewage sludge treatment and sludge reuse system based on emergy analysis in China

2021 ◽  
Vol 11 (9) ◽  
Author(s):  
Junxue Zhang ◽  
Lin Ma

AbstractAs the significant residuals in the sewage treatment system, sludge treatment and reuse play a pivotal impact on the environmental sustainability study in China. In this paper, two sewage sludge treatment systems have been investigated, calculated, and analyzed, including the conventional treatment system (Scenario A) and improved reuse system (Scenario B), respectively. The results demonstrate that (1) Compared to Scenario A, Scenario B is a comprehensive system, which integrates a sewage sludge treatment system and a brick production system for sludge recycling. (2) After considering the brick system (scenario B), on the one hand, the sludge treatment capacity has been enhanced and raised sludge utilization; on the other hand, negative influences have also generated due to the non-renewable resources input and several outputs. (3) In Scenario A and Scenario B, the input resources part reflects the main impact (about 59.6% in the entire emergy value). (4) In this new paper, the UEVs are 2.73E + 11sej/kg and 6.29E + 11sej/kg in Scenario A and Scenario B, respectively. (5) The emergy sustainability indexes (ESI) are 0.012292 and 0.00848, which express the weak comprehensive effects in Scenario A and Scenario B. (6) Scenario B has a more extensive range of change than Scenario A because of the more resource input for the sensitivity analysis. Given the all discussions, there are two effective approaches to be used for perfecting environmental sustainability in the Scenario A system and Scenario B system.

2018 ◽  
Vol 110 ◽  
pp. 8-17 ◽  
Author(s):  
Xiaohong Zhang ◽  
Ni Xiang ◽  
Wenlong Wang ◽  
Wenjie Liao ◽  
Xiangdong Yang ◽  
...  

2007 ◽  
Vol 2 (1) ◽  
Author(s):  
Petia Mijaylova Nacheva ◽  
G. Moeller-Chávez ◽  
E. Ramírez-Camperos ◽  
L. Cardoso-Vigueros

The tropical regions have specific problems associated with high pathogenic density in the sewage sludge. The aim of this study was to select an adequate sludge stabilization and valorization system comparing the performance of four technologies: anaerobic stabilization without heating, aerobic stabilization, alkaline treatment with lime and aerobic composting. The study was performed in a pilot plant which was built and operated during six months. The main problem for the beneficial use of the sludge was its pathogenicity. All the systems allowed obtaining stabilized products which met the bacteriological criteria for some kind of use. The compost and the alkalinized sludge were bacteriologically safe for use without restrictions in accordance with the Mexican regulations. The accomplishment of the parasitological criteria for use was however impossible with the anaerobic and with the aerobic systems. The compost obtained at 55-60°C with 25d aeration time and the alkaline sludge fulfill the criteria established by for forest and agriculture use and for soil conditioning. The composting could reach the requirements for unrestricted use when operated at temperatures 65-70°C during 45 days which makes it the most adequate sludge treatment system for hot climate regions.


2007 ◽  
Vol 2 (1) ◽  
Author(s):  
A. Meda ◽  
C. Schaum ◽  
M. Wagner ◽  
P. Cornel ◽  
A. Durth

TIn 2004, the German Association for Wastewater, Water and Waste (DWA) carried out a survey about the current status of sewage sludge treatment and disposal in Germany. The study covered about one third of the wastewater treatment plants and about two thirds of the entire treatment capacity (expressed in population equivalents) in Germany. This provides an up-to-date and representative database. The paper presents the most important results regarding sludge treatment, process engineering, current disposal paths and sewage sludge quality.


1993 ◽  
Vol 27 (9) ◽  
pp. 159-171 ◽  
Author(s):  
Eberhard Steinle

First an overview of the systems currently in use and being discussed for sludge treatment is presented will) particular emphasis on distinguishing between the object of the system (conditioning objective of the various phases in the system) and a system concept (concept of various phases of the system in sequence to attain the disposal objective). More detailed information is given as to the salient systems as used with smaller sewage treatment plants in rural areas, such as digestion, dewatering, hygienization, composting and thermal drying. A further item of discussion is how sludge treatment influences the sewage treatment process. For the critical emissions (nitrogen, phosphorus) demanded in Germany, and thus for the degree of sewage treatment required, the load of the sewage treatment system resulting from sludge treatment needs to be taken into account. Accordingly, operation of sludge treatment and sewage purification must always be harmonized. The extent of these return loads also limits the spatial centralization of the system phases; this applies in particular to smaller sewage treatment plants in rural areas. In conclusion, an attempt is made to present a perspective for the agricultural utilization of such sludge in Germany. Since the critical values for emissions have been further tightened by new regulations, thus considerably elevating the associated sophistication of monitoring techniques, it is to be expected that the use of sewage sludge in agriculture will also be further reduced in rural areas, especially since public awareness of emission control has considerably reduced the acceptance of sewage sludge as fertilizer.


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