scholarly journals Five Years of Rice Cultivation in Paddy Fields for Treated Water from Humus Bioreactor-Type Rural Wastewater Treatment Plants

2021 ◽  
Vol 10 (5) ◽  
Author(s):  
Hitoshi Ogawa
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plants ◽  
Rice Cultivation ◽  
Paddy Fields ◽  
Treated Water ◽  
Rural Wastewater

scholarly journals Expected Rural Wastewater Treatment Promoted by Provincial Local Discharge Limit Legislation in China

2019 ◽  
Vol 11 (10) ◽  
pp. 2756 ◽  
Author(s):  
Meishu Wang ◽  
Hui Gong
Keyword(s):  
Wastewater Treatment ◽  
Economic Burden ◽  
Wastewater Treatment Plants ◽  
Pollutant Removal ◽  
Central China ◽  
Financial Policy ◽  
Rural And Urban ◽  
Fast Development ◽  
Urban Wastewater Treatment ◽  
Rural Wastewater

Wastewater treatment in a rural region in China was undeveloped both in treatment capacity and legislation. The successful fast development of urban wastewater treatment plants (WWTPs) demonstrated the importance of legislation, including discharge limits. However, most provinces, with as high as 79.8% of the rural population in China, released no specific local discharge limits. Newly issued top-designed nationwide policy in September of 2018 by central China government required all provinces to issue their local rural wastewater discharge limits before June 2019. For the first time, this research analyzed the requirements of the newly issued policy and their inconsistence with several existing provincial limits. It proposed flexible principles for determination of discharge limits under various conditions to improve the rural residential environment as a whole. This study also proposed the use of the ratio between wastewater treatment cost and life expense to describe economic burden. Economic burden calculation for wastewater treatment in rural and urban regions was established respectively. Based on three conditions described in the new policy, the average burden for all urban residents was estimated as 0.122 ± 0.038% of the total life expense. In comparison, average nationwide rural burden was 0.087 ± 0.035% and 0.564 ± 0.196% for condition I (Total nitrogen(TN)/total phosphorus(TP) for resource recovery) and condition III (TN/TP for pollutant removal), respectively. It was also revealed that a stringent rural discharge limit lead to a Gini value as high as 0.38, indicting policy-related subsidies for rural residents should be carefully considered to ensure a balanced burden. Local discharge limit legislation and suitable financial policy is expected to promote rural wastewater treatment in China in the near future.

scholarly journals The exploitation of swamp plants for dewatering liquid sewage sludge

2006 ◽  
Vol 54 (2) ◽  
pp. 107-116
Author(s):  
Jiří Šálek
Keyword(s):  
Wastewater Treatment ◽  
Sewage Sludge ◽  
Plant Biomass ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Main Attention ◽  
Local Conditions ◽  
Economic Exploitation ◽  
Rural Wastewater

The operators of little rural wastewater treatment plants have been interested in economic exploitation of sewage sludge in local conditions. The chance is searching simply and natural ways of processing and exploitation stabilized sewage sludge in agriculture. Manure substrate have been obtained by composting waterless sewage sludge including rest plant biomass after closing 6–8 years period of filling liquid sewage sludge to the basin. Main attention was focused on exploitation of swamp plants for dewatering liquid sewage sludge and determination of influence sewage sludge on plants, intensity and course of evapotranspiration and design and setting of drying beds. On the base of determined ability of swamp plants evapotranspiration were edited suggestion solutions of design and operation sludge bed facilities in the conditions of small rural wastewater treatment plant.

scholarly journals A new method for macrolide antibiotics determination in wastewater from three different wastewater treatment plants

2017 ◽  
Vol 10 (1) ◽  
pp. 47-53 ◽  
Author(s):  
Pavlína Landová ◽  
Milada Vávrová
Keyword(s):  
Wastewater Treatment ◽  
Solid Phase Extraction ◽  
Water Samples ◽  
Ion Trap ◽  
Wastewater Treatment Plants ◽  
Solid Phase ◽  
Practical Method ◽  
Macrolide Antibiotics ◽  
Phase Extraction ◽  
Treated Water

Abstract An effective and practical method for the determination of macrolide antibiotics azithromycin, clarithromycin, erythromycin and roxithromycin in wastewater samples has been developed. The analytical method combines solid phase extraction followed by a chromatographic separation by hydrophilic interaction liquid chromatography (HILIC) coupled with an ion trap mass spectrometer utilizing the electrospray ionization technique. Detection of positively charged ions was performed in full scan mode from 500 to 900 m/z. The method detection limits and method quantification limits obtained were in the range of 2.03-7.59 ng L-1 and 6.08-23.84 ng L-1, respectively. Recoveries of solid phase extraction were obtained using SupelTM-Select HLB cartridges ranging from 85.76 % to 92.54 %. All target antibiotics were detected in 100 % of the collected raw influent samples with concentrations varying from 15 ng L-1 to 1849 ng L-1. Azithromycin, clarithromycin and erythromycin were also detected in 100 % of the treated water samples and roxithromycin was present in 96 % of the samples. The highest determined concentration in the treated water samples was 1404 ng L-1 of azithromycin. Based on the determined macrolide concentrations, removal efficiencies of individual wastewater treatment plants were calculated to range from 13 % to 100 %.

Development of a high-efficiency household biofilm reactor

1995 ◽  
Vol 31 (9) ◽  
pp. 163-171 ◽  
Author(s):  
M. Imura ◽  
Y. Sato ◽  
Y. Inamori ◽  
R. Sudo
Keyword(s):  
Wastewater Treatment ◽  
Flow Rate ◽  
High Efficiency ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Experimental Period ◽  
Biofilm Reactor ◽  
Treated Water ◽  
Experimental Apparatus ◽  
Household Wastewater

Household wastewater treatment plants have been rapidly promoted in recent years as part of the measures for reducing the pollution loading discharge from private households in Japan. The authors have developed a high-efficiency household wastewater treatment plant employing a flow equalisation anoxic-oxic recirculation biofilm process removing organic matter as well as nitrogen which causes eutrophication. A full-scale experiment has been conducted for one year by leading actual grey water (cooking, bathing, washing effluents) from a private household into the experimental apparatus. The results obtained in this study are summarised as follows: effective flow equalisation and excellent effluent quality were achieved, the maximum effluent flow rate was 100 l/h (the peak coefficient 1.5) when the maximum influent flow rate was 415 l/h (the peak coefficient 6.2), the average values of BOD5, CODMn, SS, T-N and T-P of the treated water were 7.8 mg/l, 11.1 mg/l, 5.9 mg/l, 6.4 mg/l and 1.2 mg/l, respectively BOD5 and T-N of the treated water were less than 10 mg/l during the experimental period.

Mass Flow Balances of Triclosan in Small Rural Wastewater Treatment Plants and the Impact of Biomass Parameters on the Removal

2007 ◽  
Vol 7 (1) ◽  
pp. 42-51 ◽  
Author(s):  
G. Winkler ◽  
A. Thompson ◽  
R. Fischer ◽  
P. Krebs ◽  
P. Griffin ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Mass Flow ◽  
Wastewater Treatment Plants ◽  
The Impact ◽  
Rural Wastewater

scholarly journals Intensification of activated sludge sedimentation processes by means of vacuuming

Vestnik MGSU ◽  
2021 ◽  
pp. 370-380
Author(s):  
Artem A. Kulakov ◽  
Alina F. Filatova
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Settling Tank ◽  
Municipal Wastewater Treatment ◽  
Treated Water ◽  
Mixed Liquor ◽  
Municipal Wastewater Treatment Plants ◽  
Secondary Settling

Introduction. The mixed liquor of nitrogen removal wastewater treatment plants is characterized by a high concentration of nitrates and dissolved oxygen at the inlet to the secondary settling tank. In the sludge layer of secondary sedimentation tanks, conditions of decreased oxygen content and uncontrolled denitrification processes take place. This leads to the floating up and removal of sludge with the effluent and secondary pollution of treated water. The purpose of this article is to study the parameters of activated sludge sedimentation in municipal wastewater treatment plants and their intensification by means of vacuuming. Materials and methods. The studies were carried out under laboratory conditions. Activated sludge vacuuming and sedimentation processes were simulated. Diagrams of the “sludge-water” phase reduction (Kinsh curves) were drawn. Mathematical and graphic processing of the results was carried out. Results. Biological treatment of municipal wastewater (aerotank — secondary settling tank) and methods of its intensification by influencing the activated sludge were considered in this article. Trends of activated sludge (at different concentrations of mixed liquor suspended solids) sedimentation were experimentally obtained for municipal wastewater treatment plants. The process of sludge vacuuming was researched, the process efficiency was determined as a function of the treatment time. Conclusions. Vacuuming allows removing gases from the fluid, which accelerates the process of sludge separation from the treated water and prevents it from floating to the surface. The treated sample is characterized by better sedimentation characteristics, density, coarseness and integrity of flakes. The optimal duration of mixed liquor vacuuming before sedimentation is 0.5 minutes; this accelerates the processes of subsequent sedimentation and reduces the removal of sludge with treated water. The results of laboratory tests can be applied to the design of the mixed liquor vacuuming unit before the secondary sedimentation tanks and its sludge separation.

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