Reuse of Chemical Sludge for Conditioning of Biological Sludges

1988 ◽  
pp. 291-306 ◽  
Author(s):  
Y. Watanabe ◽  
A. Toyoshima
Keyword(s):  
Chemical Sludge

Arsenic removal by MF membrane with chemical sludge adsorption and NF membrane equipped with vibratory shear enhanced process

2003 ◽  
Vol 3 (5-6) ◽  
pp. 303-310 ◽  
Author(s):  
S.-H. Yi ◽  
S. Ahmed ◽  
Y. Watanabe ◽  
K. Watari
Keyword(s):  
Arsenic Removal ◽  
Membrane Surface ◽  
Membrane Process ◽  
Low Concentrations ◽  
Strong Shear ◽  
Low Levels ◽  
Removal Processes ◽  
Removal Of Arsenic ◽  
Concentration Polarization Layer ◽  
Chemical Sludge

Conventional arsenic removal processes have difficulty removing low concentrations of arsenic ion from water. Therefore, it is very hard to comply with stringent low levels of arsenic, such as below 10 μg/L. So, we have developed two arsenic removal processes which are able to comply with more stringent arsenic regulations. They are the MF membrane process combined with chemical sludge adsorption and NF membrane process equipped with the vibratory shear enhanced process (VSEP). In this paper, we examine the performance of these new processes for the removal of arsenic ion of a low concentration from water. We found that chemical sludge produced in the conventional rapid sand filtration plants can effectively remove As (V) ions of H2AsO4- and HAsO42- through anion exchange reaction. The removal efficiency of MF membrane process combined with chemical sludge adsorption increased to about 36%, compared to MF membrane alone. The strong shear force on the NF membrane surface produced by vibration on the VSEP causes the concentration polarization layer to thin through increased back transport velocity of particles. So, it can remove even dissolved constituents effectively. Therefore, As (V) ions such as H2AsO4- and HAsO42- can be removed. The concentration of As (V) ions decreased from 50 μg/L to below 10 μg/L and condensation factor in recirculating water increased up to 7 times by using NF membrane equipped with VSEP.

Use in Agriculture of Sludge from Chemical Treatment of Sewage

1987 ◽  
Vol 19 (8) ◽  
pp. 139-145
Author(s):  
G. Castillo ◽  
A. Ortega
Keyword(s):  
Sodium Hydroxide ◽  
Chemical Treatment ◽  
Application Rate ◽  
Additional Treatment ◽  
Fecal Coliforms ◽  
Aluminium Sulfate ◽  
Leguminous Crops ◽  
Dried Sludge ◽  
Chemical Sludge ◽  
Sludge Application

The reutilization in agriculture of the sludge produced in the chemical treatment of sewage is investigated. Aluminium sulfate (50 mg/l) and sodium hydroxide (50 and 200 mg/l) are added to domestic sewage allowing it to settle and eliminating floating materials. Three kinds of raw chemical sludge are digested and dried. Their sanitary quality is determined by two bacterial indicators (total and fecal coliforms) and one viral indicator (E. coli bacteriophage) and the fertilizing capability of digested and dry sludge by sowing leguminous crops (Phaseolus spp ) in soil with 11 tons/ha sludge application rate. Digested and dried sludge from conventional treatment in equal conditions to those of chemical sludge is used as reference. Sanitary quality results show that raw and digested chemical sludge are not recommended for use in agriculture due to their high microbiological contamination. Dry sludge could be considered for this purpose due to its low fecal organisms content. However the development of leguminous crops in soil with dry aluminium sludge application shows no seed germination. The results of leguminous growth in digested sludge of sodium hydroxide (200 mg/l) justify an additional treatment to adequate its sanitary quality for use in agriculture.

Coupled heating/acidification pretreatment of chemical sludge for dewatering by using waste sulfuric acid at low temperature

Chemosphere ◽  
2018 ◽  
Vol 205 ◽  
pp. 260-266 ◽  
Author(s):  
Bo Bian ◽  
Limin Zhang ◽  
Qin Zhang ◽  
Shaopeng Zhang ◽  
Zhen Yang ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Low Temperature ◽  
Chemical Sludge

Slagging and fouling characteristics during co-combustion of Scots pine bark with low-temperature dried pulp and paper mill chemical sludge

2019 ◽  
Vol 193 ◽  
pp. 282-294 ◽  
Author(s):  
Alejandro Grimm ◽  
Jarkko Etula ◽  
Roushdey Salh ◽  
Gunnar Kalén ◽  
Markus Segerström ◽  
...  
Keyword(s):  
Low Temperature ◽  
Scots Pine ◽  
Paper Mill ◽  
Pulp And Paper ◽  
Pine Bark ◽  
Pulp And Paper Mill ◽  
Chemical Sludge ◽  
Fouling Characteristics

Influence d'un préconditionnement chimique sur l'épaississement gravitaire et la déshydratation de boues d'étangs aérés facultatifs

1995 ◽  
Vol 22 (6) ◽  
pp. 1198-1216
Author(s):  
Marc-André Desjardins ◽  
Charles Bussières ◽  
François G. Brière ◽  
Danielle Dagenais
Keyword(s):  
Key Words ◽  
Capture Rate ◽  
Great Difficulty ◽  
Solid Content ◽  
Cationic Polymers ◽  
Dual Effect ◽  
Biological Sludge ◽  
Gravity Thickening ◽  
Chemical Sludge

This article presents the results of a study on the influence of chemical preconditioning on gravity thickening and dewatering of biological and chemical sludge (alum dephosphatation sludge) from facultative aerated lagoons. Four reagents have been studied: two cationic polymers and two inorganic reagents. Inorganic reagents have not improved gravity thickening of sludge while polymers were more efficient. Polymers have a dual effect: they increase capture rate and accelerate solids settling. Biological sludge from lagoons thickens easily and may reach 10 to 12% dry solid contents, with or without the addition of polymers. On the contrary, chemical sludge thickens with great difficulty. Even with the addition of polymers, the maximum dry solid content did not reach more than 3.8% for sludge with initial dry solid content of 1.25% approximately. However, higher dry solid content can be obtained if the initial dry solid content of sludge is higher. Therefore, it is important to minimize dilution during the extraction of sludge from lagoons. Finally, the addition of polymers to sludge to help thickening does not affect the reconditioning of sludge to be dewatered except possibly in the case of mechanically dewatered chemical sludge treated with chemical conditioning. Key words: chemical preconditioning, gravity thickening, dewatering, sludge, facultative aerated lagoons.

Evaluation of chemical sludge production in wastewater treatment processes

2015 ◽  
Vol 57 (35) ◽  
pp. 16346-16352 ◽  
Author(s):  
Natália Rodrigues Guimarães ◽  
Sidney Seckler Ferreira Filho ◽  
Bruno Piotto Hespanhol ◽  
Roque Passos Piveli
Keyword(s):  
Wastewater Treatment ◽  
Treatment Processes ◽  
Chemical Sludge ◽  
Sludge Production

Elimination of chemical sludge for treatment of tannery wastewater and its effect on biogas generation

2018 ◽  
Vol 131 ◽  
pp. 162-168
Author(s):  
K. Sri Bala Kameswari ◽  
Chitra Kalyanaraman ◽  
B. Abirami ◽  
K. Thirumaran
Keyword(s):  
Tannery Wastewater ◽  
Chemical Sludge

Combination of coagulation and catalytic wet oxidation for the treatment of pulp and paper mill effluents

2001 ◽  
Vol 44 (5) ◽  
pp. 145-152 ◽  
Author(s):  
S. Verenich ◽  
A. Laari ◽  
M. Nissen ◽  
J. Kallas
Keyword(s):  
Paper Mill ◽  
Thermomechanical Pulp ◽  
Wet Oxidation ◽  
Pulp And Paper Mill ◽  
Catalytic Wet Oxidation ◽  
Paper Mills ◽  
Paper Mill Effluents ◽  
Suitable Combination ◽  
Chemical Sludge ◽  
Positive Effect

Wet oxidation (WO) is a well established process for purification of concentrated municipal and industrial wastewaters. Many attempts have been made to modify the WO process or to create a suitable combination of processes. This work was undertaken to investigate wet oxidation integrated with coagulation, i.e. to treat the sludge remaining after coagulation with a WO process. The possibility of regeneration of the used coagulant was also considered. Two waters from paper mills were used: TMP (thermomechanical pulp) circulation water and membrane concentrate. About 50% of the COD in the original water can be removed by coagulation using Fe2(SO4)3. The results from the wet oxidation experiments show the positive effect of iron in the chemical sludge as a catalyst. The efficiency of the WO process was enhanced almost by 100%. The remaining dissolved organic matter can be easily removed biologically.

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