Study on the Solidification/Stabilization Treatment of Tannery Sludge

2011 ◽  
Vol 356-360 ◽  
pp. 1951-1954
Author(s):  
Yu Tian ◽  
Xu Nan Ning ◽  
Jing Yong Liu ◽  
Jian Bo Zhou ◽  
Zuo Yi Yang ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Compressive Strength ◽  
Moisture Content ◽  
Curing Time ◽  
Tannery Sludge ◽  
Optimum Conditions ◽  
Toxic Heavy Metals ◽  
Stabilization Treatment

Sludge from tannery was solidified and stabilized by using lime, PFA and cinder as the solidifying agents，investigation of solidifying agents affect toxic heavy metals in tannery sludge and the optimum conditions of sludge solidification/stabilization were analyzed. The results showed that under the dosage of lime, PFA and cinder were 0.12kg/kg, 0.02kg/kg and 0.08kg/kg respectively, and curing time was 6 days, the compressive strength of the solidified sludge block reached 884KPa while the moisture content of the solidification block was 30.2%，which met with the standards of landfill. Compared with the untreated tannery sludge，the concentration of Cu、Pb、Zn、Ni and COD of the leaching from the sludge solidification block was reduced by 92.1%、96.7%、92.8%、88.9% and 75.9% respectively，the Cr、Cd、and Mn were undetectable.When lime and PFA ratio was 6:1, the solidified block have good synergistic solidification effects.

scholarly journals Influence of Nanolime and Curing Period on Unconfined Compressive Strength of Soil

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Panbarasi Govindasamy ◽  
Mohd Raihan Taha ◽  
Jamal Alsharef ◽  
Kowstubaa Ramalingam
Keyword(s):  
Compressive Strength ◽  
Moisture Content ◽  
Unconfined Compressive Strength ◽  
Curing Time ◽  
Strength Gain ◽  
Treated Soil ◽  
Soil Particles ◽  
Curing Period

This paper presents the improvement of the unconfined compressive strength (UCS) of soil by mixing different percentages of nanolime and 5% lime with soil. The UCS of treated soil increased significantly over curing time with increasing percentage of nanolime. The optimum results were reached at only 0.5% nanolime admixtures which were much higher than 5% lime admixture. This may be due to higher ability of nanolime to flocculate and agglomerate the soil particles compared with the lime. In addition, the lime could fill only the micropores while nanolime could fill the micro- and nanopores as well. The strength gain is inversely proportional to the remolded moisture content and curing period. However, when the content of nanolime used is larger than 0.5%, nanolime particles are not uniformly dispersed. Therefore, a weak area in the form of voids is created, consequently the homogeneous hydrated microstructure cannot be formed, and finally the strength will decrease.

Experimental Study on the Solidification/Stabilization of Textile Dyeing Sludge

2011 ◽  
Vol 197-198 ◽  
pp. 1010-1015
Author(s):  
Xun An Ning ◽  
Jian Bo Zhou ◽  
Jing Yong Liu ◽  
Zuo Yi Yang ◽  
Yu Tian ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Compressive Strength ◽  
Oxygen Demand ◽  
Heavy Metal Concentration ◽  
National Standards ◽  
Curing Time ◽  
Optimum Conditions ◽  
Heavy Metal Concentrations ◽  
Textile Dyeing ◽  
Compressive Strength Test

Sludge from the textile dyeing industries was solidified and stabilized using cement, fly ash（PFA）and cinder as the solidifying agents, and the optimum conditions of sludge solidification/stabilization were analyzed. The mechanical property of solidified sludge block was evaluated by compressive strength test, at the same time， the chemical oxygen demand (COD） and heavy metal concentration of the leaching from the cured block were tested as well. With the dosage of cement, PFA and cinder, 0.15kg/kg, 0.02kg/kg and 0.08kg/kg respectively, and curing time was 6ds, the compressive strength of the solidified sludge block reached 330kPa.Results showed that addition of cement and cinder had good effects on the compressed strength of sludge block, cement, PFA and cinder enhanced the solidification and stabilization of organic and heavy metal in the sludge. Under the above conditions, COD of the leaching from the sludge solidification block was 488mg/L, and the heavy metal concentrations had reached the related national standards. After 6ds of curing time, water ratio of the solidified block was maintained at 40%~45%, which met the prescribed standards of landfill.

Experimental Study on New Technology for Solidifying/Stabilizing Papermaking Sludge

2010 ◽  
Vol 156-157 ◽  
pp. 84-89
Author(s):  
Xu Nan Ning ◽  
Shi Wen Li ◽  
Jing Yong Liu ◽  
Zuo Yi Yang ◽  
Zhu Ying
Keyword(s):  
Mechanical Properties ◽  
Heavy Metals ◽  
Heavy Metal ◽  
Compressive Strength ◽  
New Technology ◽  
Oxygen Demand ◽  
Heavy Metal Concentration ◽  
National Standards ◽  
Curing Time ◽  
Water Ratio

For better harmlessly treatment of papermaking sludge, a new technology for solidifying and stabling of sludge was studied. Papermaking sludge was solidified and stabilized by the solidifying agents including cement, powder fly ash (PFA) and cinder. The mechanical properties of solidified sludge block were evaluated by compressive strength, chemical oxygen demand (COD) and heavy metals concentration in the leachate from the solidified block were tested as well. When the solidifying agents has the following composition (cement 0.12kg/kg, PFA 0.02kg/kg and cinder 0.10kg/kg respectively), and the curing time was 6ds, the compressive strength of the solidified sludge blocks reached 360kPa. The results showed that cement and cinder were all positive in the compressed strength of sludge block. If they were mixed with PFA together, they could enhanced the solidification of organic and heavy metals in the sludge. Under this conditions, the COD in leachate from the solidified block was 115.7 mg/L, and the heavy metal concentration had reached the related national standards, after 6ds of curing time, water ratio of the solidified block kept from 35% to 40%, which met the prescribed standards of landfill.

scholarly journals Variations of moisture content in manufacturing CLT-concrete composite slab using wet construction method

BioResources ◽  
2020 ◽  
Vol 16 (1) ◽  
pp. 372-386
Author(s):  
Yo-Jin Song ◽  
Seong-Yeob Baek ◽  
In-Hwan Lee ◽  
Soon-Il Hong
Keyword(s):  
Compressive Strength ◽  
Moisture Content ◽  
Production Process ◽  
Construction Method ◽  
Curing Time ◽  
Cross Laminated Timber ◽  
High Rise ◽  
Bonding Method ◽  
Concrete Component

Construction of eco-friendly high-rise buildings using cross-laminated timber (CLT)-concrete composite (CCC) slabs is increasing. CLT and concrete, which are major component materials of the CCC slab, are significantly affected by moisture. In particular, the moisture content of concrete in the production process affects the quality of both materials. In this study, the effects of the wet construction method on CLT and concrete component materials are examined by monitoring the behavior of the CCC slab during curing time (28 d) and by evaluating the quality of the concrete and CLT after curing. When manufacturing the CCC using the wet construction method, moisture penetration from the concrete into the CLT during the curing time is suppressed by the shear bonding between the concrete and the CLT when an adhesive is used. This minimizes the effect of the moisture on both component materials, consequently yielding uniform compressive strength to the concrete after curing and preventing the deterioration of the CLT’s delamination performance. Therefore, the shear bonding method using an adhesive is expected to minimize the quality deterioration observed in concrete and CLT after curing.

Research on the Preparation of Baking-Free Brick Using the Tailings of Flue Gas Desulfurization of Pyrolusite Slurry

2013 ◽  
Vol 726-731 ◽  
pp. 2771-2777
Author(s):  
Zheng Zhou ◽  
Cheng Qiu
Keyword(s):  
Particle Size ◽  
Compressive Strength ◽  
Moisture Content ◽  
Flue Gas ◽  
Water System ◽  
Cementitious Materials ◽  
Flue Gas Desulfurization ◽  
Curing Time ◽  
Test Results ◽  
Optimal Parameters

This paper studies the preparation of baking-free brick using the tailings of flue gas desulfurization of pyrolusite slurry, aiming to explore the optimal technological conditions. Experimental results show that the particle size of the tailings of flue gas desulfurization of pyrolusite slurry with the concentration up to 95% is below 80μm, which are the appropriate material for the preparation of baking-free bricks. "Byproduct tailings of flue gas desulfurization of pyrolusite slurry - cement cementitious materials - water" system is a relatively good ingredient program. The test results indicate that the flexural and compressive strength of the baking-free brick sample increases with the rise of forming pressure. Appropriately adding the dosage of binder could improve the flexural and compressive strength of the baking-free brick sample, but when it is added to a certain degree, the strength will decrease instead. To sum up, the optimal parameters of the baking-free brick product are shown as follows: desulfurization tailings: cementitious materials = 5:1, the forming pressure is 20 MPa, the moisture content is 10% and the natural curing time is controlled in the range of 7-28 days.

scholarly journals Solidification/Stabilization of Fly Ash from a Municipal Solid Waste Incineration Facility Using Portland Cement

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Qiang Tang ◽  
Yang Liu ◽  
Fan Gu ◽  
Ting Zhou
Keyword(s):  
Heavy Metals ◽  
Compressive Strength ◽  
Fly Ash ◽  
Portland Cement ◽  
Metal Ion ◽  
Waste Incineration ◽  
Pozzolanic Reaction ◽  
Strength Ratio ◽  
Curing Time ◽  
Ion Migration

This study investigated the solidification/stabilization of fly ash containing heavy metals using the Portland cement as a binder. It is found that both the cement/fly ash ratio and curing time have significant effects on the mechanical (i.e., compressive strength) and leaching behaviors of the stabilized fly ash mixtures. When the cement/fly ash ratio increases from 4 : 6 to 8 : 2, the increase of compressive strength ratio raises from 42.24% to 80.36%; meanwhile, the leaching amount of heavy metals decreases by 2.33% to 85.23%. When the curing time increases from 3 days to 56 days, the compressive strength ratio of mixtures raises from 240.00% to 414.29%; meanwhile, the leaching amount of heavy metals decreases by 16.49% to 88.70%. The decrease of compressive strength with the lower cement/fly ash ratios and less curing time can be attributed to the increase of fly ash loading, which hinders the formation of ettringite and destroys the structure of hydration products, thereby resulting in the pozzolanic reaction and fixation of water molecules. Furthermore, the presence of cement causes the decrease of leaching, which results from the formation of ettringite and the restriction of heavy metal ion migration in many forms, such as C-S-H gel and adsorption.

Carbonate Steelmaking Slag to Manufacture Building Materials

2009 ◽  
Vol 79-82 ◽  
pp. 1943-1946 ◽  
Author(s):  
Hao Ze Wu ◽  
Jun Chang ◽  
Zheng Zhao Pan ◽  
Xin Cheng
Keyword(s):  
Compressive Strength ◽  
Reaction Time ◽  
Moisture Content ◽  
Greenhouse Gas ◽  
Reaction Temperature ◽  
Building Materials ◽  
New Technology ◽  
Steelmaking Slag ◽  
Curing Time ◽  
Accelerated Carbonation

Accelerated carbonation is a new technology of materials preparation, which may have potential for the treatment of industrial solid residues and the sequestration of CO2, an important greenhouse gas. In this study, accelerated carbonation was used to recycle steelmaking slag and sequestrate CO2 to manufacture building materials. The experimental results show that the strength of specimens increases along with the increase of carbonation degree. Moisture content, carbonation temperature and curing time have significant effects on the degree of carbonation, and carbonated specimens have larger weight increase and compressive strength increases under the condition of moisture content 12.6%，reaction time 117 min and reaction temperature 361 K. The SEM and XRD analyses indicate that dogtooth like CaCO3 crystals appear on the surface of carbonated aggregate specimens. Strength and soundness test shows that steelmaking slag building materials have higher strength and eligible soundness after accelerated carbonation.

scholarly journals INFLUENCE OF SYNTHESIS FACTORS ON PROPERTIES OF GEOPOLYMERS BASED ON RED MUD AND RICE HUSK ASH

2017 ◽  
Vol 55 (4) ◽  
pp. 461
Author(s):  
Tran Ngoc Tuyen ◽  
Nguyen Duc Vu Quyen ◽  
Ho Van Minh Hai ◽  
Dang Xuan Tin ◽  
Tran Ngoc Quang
Keyword(s):  
Compressive Strength ◽  
Rice Husk ◽  
Red Mud ◽  
Rice Husk Ash ◽  
Raw Materials ◽  
Curing Temperature ◽  
Mixing Ratio ◽  
Curing Time ◽  
Optimum Conditions ◽  
Total Shrinkage

In this paper, the effect of mixing ratio of raw materials, curing temperature and time on geopolymerization between red mud and rice husk ash were investigated. The results showed that the optimum conditions were SiO2/Al2O3 ratio of 4 and Na2O/Al2O3 ratio of 2.0, curing temperature of 100oC and curing time of 24 hours. The compressive strength, bulk density, total shrinkage of the obtained product were 22.8 MPa, 2.39 g.cm-3, 15%, respectively that met requirement of unsintered bricks using for construction.

ASSESSMENT OF HEAVY METAL CONCENTRATION IN COCONUT WATER

1970 ◽  
pp. 07-10
Author(s):  
MdDidarul Islam, Ashiqur Rahaman, Aboni Afrose
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Heavy Metal Concentration ◽  
Coconut Water ◽  
Toxic Heavy Metals ◽  
High Concentration ◽  
Toxic Heavy Metal ◽  
Low Concentration ◽  
Wet Ashing ◽  
Aas Method

This study was based on determining concentration of essential and toxic heavy metal in coconut water available at a local Hazaribagh area in Dhaka, Bangladesh. All essential minerals, if present in the drinking water at high concentration or very low concentration, it has negative actions. In this study, fifteen samples and eight heavy metals were analyzed by Atomic Absorption Spectroscopy (AAS) method which was followed by wet ashing digestion method. The concentration obtained in mg/l were in the range of 0.3 to 1.5, 7.77 to 21.2, 0 to 0.71, 0 to 0.9, 0 to 0.2, 0.9 to 17.3, 0.1 to 0.9, 0 to 0.9 and 0 to 0.7 for Fe, Ni, Cu, Cd, Cr, Zn, Pb and Se respectively. From this data it was concluded that any toxic heavy metals like Cd, Cr, Pb and Ni exceed their toxicity level and some essential nutrients were in low concentration in those samples. 

Assessment of micro and macro nutrients in poultry feeds available in Dhaka city, Bangladesh.

2017 ◽  
Vol 1 ◽  
pp. 264
Author(s):  
Md Didarul Islam ◽  
Ashiqur Rahaman ◽  
Fahmida Jannat
Keyword(s):  
Heavy Metals ◽  
Adverse Effect ◽  
The Other ◽  
Nutrient Level ◽  
Dhaka City ◽  
Toxic Heavy Metals ◽  
High Concentration ◽  
Low Concentration ◽  
Feed Formulation ◽  
Macro Nutrients

This study was based on to determine the concentration of macro and micro nutrients as well as toxic and nontoxic heavy metals present in the chicken feed available in Dhaka city of Bangladesh. All macro nutrients, if present in the feed at high concentration have some adverse effect, at the same time if this nutrient present in the feed at low concentration this have some adverse effect too. So that this nutrient level should be maintained at a marginal level. On the other side toxic heavy metals if present in the feed at very low concentration those can contaminate the total environment of the ecosystem. In this study six brand samples (starter, grower, finisher and layer) which was collected from different renowned chicken feed formulation industry in Bangladesh. Those samples were prepared for analysis by wet ashing and then metals were determined by Atomic Absorption Spectroscopy. It was found that 27.7 to 68.4, 57.3 to 121.9, 0.21 to 4.1, 0.32 to 2.1, 0.11 to 1.58, 0.28 to 2.11 and 0.28 to 1.78 for zinc, iron, copper, mercury, cadmium, nickel and cobalt respectively. It was found that essential macro and micro nutrients were present in the feed in low concentration on the other side mercury was present in high concentration in the feed samples.

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