Extraction efficiency of phosphate from pre-coagulated sludge with NaHS

2006 ◽  
Vol 54 (5) ◽  
pp. 119-129 ◽  
Author(s):  
F. Kato ◽  
H. Kitakoji ◽  
K. Oshita ◽  
M. Takaoka ◽  
N. Takeda ◽  
...  
Keyword(s):  
Sewage Sludge ◽  
Mass Balance ◽  
Extraction Method ◽  
Extraction Efficiency ◽  
Sewage Treatment ◽  
Limited Resource ◽  
High Concentration ◽  
Sludge Treatment ◽  
Extraction Mechanism ◽  
Sewage Treatment Plants

The recovery of phosphorus from sewage and sludge treatment systems is particularly important because it is a limited resource and a large proportion of the phosphorus currently used in Japan must be imported. We have been experimentally evaluating recovery methods with sulphide. In this study, we focussed on the extraction of phosphate from the sludge, and sought to achieve a greater extraction efficiency and to validate the extraction mechanism. We conducted three experiments, i.e. a sludge-type experiment, a coagulant ratio of pre-coagulated sludge experiment, and a concentration of pre-coagulated sludge experiment. Phosphate was extracted not with normal sewage sludge but with pre-coagulated sludge and FePO4 reagent at S/Fe=1.0–2.0. A coagulant ratio of 23 mg Fe L−1 was required in the pre-coagulation process to effectively extract phosphate. A high concentration of pre-coagulated sludge was required for the phosphate extraction. The mass balance was calculated, and 44.0% of phosphorus was extracted to supernatant, and 98.5% of iron and 98.3% of sulphur (44.1% of sulphur was sulphide). Thus, phosphate can be selectively separated from iron by the phosphate extraction method with NaHS, and phosphorus and iron can be recovered and reused at sewage treatment plants using ferric chloride as a coagulant.

Sludge Treatment and Disposal Systems for Rural Areas in Germany

1993 ◽  
Vol 27 (9) ◽  
pp. 159-171 ◽  
Author(s):  
Eberhard Steinle
Keyword(s):  
Sewage Sludge ◽  
Rural Areas ◽  
Public Awareness ◽  
Sewage Treatment ◽  
Treatment Needs ◽  
Sludge Treatment ◽  
Sewage Treatment Plants ◽  
Sewage Purification ◽  
Treatment And Disposal ◽  
Nitrogen Phosphorus

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.

Recycling to Soils: a Sustainable Way of Sludge Disposal and its Practice in China

2011 ◽  
Vol 183-185 ◽  
pp. 1417-1422 ◽  
Author(s):  
Xiang Sheng Cao ◽  
Xue Jing Meng ◽  
Xue Zheng Meng
Keyword(s):  
Sewage Treatment ◽  
Land Application ◽  
Sludge Treatment ◽  
Sewage Treatment Plants ◽  
Sludge Disposal ◽  
Successful Case ◽  
Urgent Task ◽  
Before And After ◽  
Treatment And Disposal ◽  
Disposal Problem

With the booming construction of sewage treatment plants aiming at environmental protection, China has to face an emerging urgent task to address the sludge treatment and disposal problem. However there is a big controversy in China about the sludge treatment and disposal strategies. Some scientists suggest incinerating, while others insist on landfilling. In this paper, from the perspective of sustainable development and cyclic economy, a detailed analysis of nutrients cycle mainly related to nitrogen and phosphate before and after industrialization was made and a view that sludge should go back to soils to re-establish a sound nutrients cycle was put forward. Then the feasibility for sludge recycle to soils was discussed and some land application methods for sludge were introduced. At last, a successful case of producing compounded fertilizer from dewatered sludge in Northeast China was described in detail.

Development of a routine analytical procedure for nonylphenol polyethyoxylates and their biodegradation products in sludge from sewage treatment plants

2001 ◽  
Vol 44 (10) ◽  
pp. 101-106 ◽  
Author(s):  
M. Tateda ◽  
N.V. Hung ◽  
H. Kaku ◽  
M. Asano ◽  
M. Ike ◽  
...  
Keyword(s):  
Quantitative Analysis ◽  
Sewage Sludge ◽  
High Performance ◽  
Analytical Procedure ◽  
Sewage Treatment ◽  
Soxhlet Extraction ◽  
Average Concentration ◽  
Recovery Efficiency ◽  
Sewage Treatment Plants ◽  
Freeze Dried

A method of quantitative analysis of nonylphenol polyethoxylates (NPnEOs) and their biodegration products (NPE-BDPs) in sewage sludge, which is effective, economical, and applicable to a high performance liquid chromatography was developed and actual sludge samples collected from Japanese sewage treatment plants (STPs) were analyzed using the method to confirm its effectiveness. Soxhlet extraction showed better recovery in a spike and recovery test than shaking extraction. Among the four pretreatments for Soxhlet extraction tested, the condition in which samples were freeze-dried, ultrasonicated, and extracted with methanol showed the best recovery efficiency. Quantitative analysis of NPE-BDPs in STP sludge resulted in 6.1 μg/g, 4.3 μg/g, and 8. μg/g in average concentration for NPnEOs (n=1-3), NPnEOs (n=4-18), and nonylphenol ethoxycarboxylates (NPnECs (n=1-3)), respectively, and the values of concentration were 100-1000 times higher than those in effluent at Japan's STPs. The results implied importance of quantitation of NPE-BDPs in sewage sludge to assess the risk to the environment.

scholarly journals Diplopods as Soil Bioindicators of Toxicity After Application of Residues From Sewage Treatment Plants and Ethanol Industry

2016 ◽  
Vol 22 (5) ◽  
pp. 1098-1110 ◽  
Author(s):  
Cintya A. Christofoletti ◽  
Annelise Francisco ◽  
Janaína Pedro-Escher ◽  
Vinícius D. Gastaldi ◽  
Carmem S. Fontanetti
Keyword(s):  
Sewage Sludge ◽  
Brush Border ◽  
Histological Analysis ◽  
Sewage Treatment ◽  
Behavioral Analysis ◽  
Sewage Treatment Plants ◽  
Hepatic Cells ◽  
Tissue Responses ◽  
Sugarcane Vinasse ◽  
High Absorption

AbstractResidues like sewage sludge and vinasse have been reused as agricultural fertilizers, but they also present a potential to contaminate soils. Diplopods have been considered excellent bioindicators of soil contamination. In the present study, Rhinocricus padbergi were used to assess toxicity in samples of sewage sludge, biosolids, and sugarcane vinasse. The behavioral analysis, mortality rate, and histological, histochemical, and ultrastructural analyses of the midgut of diplopods were the parameters evaluated. Behaviorally, some diplopods avoided burying themselves after 30 days in soil with biosolid or vinasse. Besides, certain residue combinations were able to cause death of all individuals between 60 and 90 days of exposure. The main tissue responses were significant brush border thickening, induction of epithelial renovation, clustering of hemocytes, accumulation of cytoplasmic granules in hepatic cells, hepatic cells with heteropycnotic nuclei, and cytoplasmic degradation. Alterations were observed at various levels among treatments with different samples and exposure times. Ultrastructural analysis revealed elongation of microvilli coated with a layer of an amorphous substance, resulting in a thicker brush border as observed in the histological analysis. After 30 days of exposure, animals showed an accumulation of spherocrystals in hepatic cells and high absorption of substances, based on the elongation of microvilli. Results obtained in the chemical analysis and the behaviors observed in diplopods suggest that animals processed the residues. Therefore, caution should be exercised in the disposal of these residues in agriculture.

On the Issue of Monitoring Odor-Generating Volatile Pollutants during Sewage Treatment Plant Operation

2020 ◽  
pp. 52-55
Author(s):  
EV Zaritskaya ◽  
PA Ganichev ◽  
AYu Mikheeva ◽  
OL Markova ◽  
GB Yeremin ◽  
...  
Keyword(s):  
Sewage Sludge ◽  
High Performance ◽  
Local Population ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Analytical Techniques ◽  
Ambient Air ◽  
Sewage Treatment Plants ◽  
Study Results

Summary. Introduction: The problem of strong offensive odor produced by operation of sewage treatment plants is known to be quite pressing and common. It is now related to the fact that urban development made these plants, once built on the outskirts, appear within city boundaries, near summerhouses and cottage villages. Malodor is perceived by local population as a sign of poor ambient air quality that evokes negative emotions and unfavorable reflex responses and makes most people feel unwell. Materials and methods: We analyzed sewage sludge from wastewater treatment plants for the whole range of chemicals that can migrate into ambient air and identified priority odor-generating pollutants. Sewage sludge testing was carried out in simulated conditions using advanced high-precision analytical techniques such as mass-spectrometry, spectrophotometry, fluorimetry, gas chromatography, and high performance liquid chromatography. Conclusions: Based on study results, we developed a list of chemicals subject to laboratory monitoring and substantiated the expediency of their detection in the presence of public complaints of offensive odors coming from sewage treatment plants.

scholarly journals Alterations in the Fat Body Cells of Rhinocricus padbergi (Diplopoda) Resulting from Exposure to Substrate Containing Sewage Sludge

2012 ◽  
Vol 18 (2) ◽  
pp. 317-323 ◽  
Author(s):  
Raphael Bastão de Souza ◽  
Carmem Silvia Fontanetti
Keyword(s):  
Sewage Sludge ◽  
Fat Body ◽  
Close Contact ◽  
Sewage Treatment ◽  
Degraded Soil ◽  
Sewage Treatment Plants ◽  
Morphological Alterations ◽  
Ecotoxicological Tests ◽  
Treated Sewage ◽  
Toxic Agents

AbstractThe final disposal of residues generated at sewage treatment plants (STPs) has become a major problem for cities, due to the increase in the amount of treated sewage. One of the alternatives for the residue, labeled “sewage sludge,” is its reuse in agriculture and in degraded soil. However, not all pathogens and metals present in it are eliminated during treatment. Diplopods have been used as bioindicators in ecotoxicological tests as they are constantly in close contact with the soil. Owing to this fact, the purpose of this study was to expose specimens of the diplopod Rhinocricus padbergi to substrate containing sewage sludge collected at STPs to analyze morphological alterations in their parietal and perivisceral fat body, where substances are stored. The exposures were held for 7, 15, or 90 days at different concentrations of sewage sludge (control, 1%, 10%, and 50%). The parietal fat body showed no alterations in any of the three exposure periods or concentrations. Alterations in the perivisceral fat body were observed for all exposure periods. According to the results, we suggest that the sludge used has toxic agents responsible for changing the animal's perivisceral fat body.

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