The growth of the electronics industry can also mean that a large amount of industrial waste water is released, resulting in electroplating (ES) sludge, which is considered a hazardous waste due to the high concentration of heavy metals in the sludge. The raw galvanic sludge was heat treated to produce two different samples which were oven dried ES (105 °C oven for 24 h) and ES ash (550 °C oven 2 h). Oven-dried ES and ES fly ash were encapsulated in cement mortar as a cement replacement material in a specific ratio to determine optimum strength and performance and dried for 28 days.
The best compressive strength was 23.80 N/mm2 when furnace-burned galvanic sludge ash with 10% cement was used, which was higher than the 21.16 N/mm2 of conventional cement mortar. The heat treatment and encapsulation of electroplating sludge paves the way for a more environmentally friendly and green material, and makes the encapsulated electroplating sludge ash commercially viable in cement mortar. Her constructive advice and feedback that motivated and encouraged me during my graduation project.
Finally, I would like to thank my family and friends for their unwavering support and encouragement throughout my senior year project.
INTRODUCTION
- Background Study
- Generation of Electroplating Sludge
- Problem Statement
- Research Objective
- Scope of Work and Study
The growth of the electronics industry can also mean that a large amount of industrial waste water is released. The concentrated wastewater was pumped into a system that uses high temperature to evaporate the wastewater, as shown in Figure 3. The wastewater then went through a rapid mixing stage (coagulation) followed by a slow mixing stage (flocculation).
In the next step, the wastewater was then transferred to a pH adjustment tank to rebalance the pH. Waste management, which converts waste into the production of chemicals and products that can be used in everyday life, is becoming a key source of employment to meet the needs of a rapidly growing world population. To investigate the optimum replacement percentage of dried electroplating sludge and electroplating sludge ash in mortar.
The purpose of the work and study of this project is exclusively to stabilize/harden the electroplating sludge from Murata Sdn.
LITERATURE REVIEW
- Electroplating Sludge
- Stabilization/ Solidification of Electroplating Sludge
- Cement Replacement Material
- Cementitious Properties of OPC and ES
- Toxicity Characteristic Leaching Procedure (TCLP)
The goals of stabilization and solidification would be to reduce waste toxicity and mobility while improving the technical properties of the stabilized material (Varinder K, 2017). Waste is mixed with cementitious additives to generate an inert and stable solid material that can be properly disposed of on land during the solidification/stabilization process. The purpose of the solidification/stabilization methods is to keep hazardous waste components within legal limits, to produce a solid material from liquid waste or sludge, to improve the physical and handling properties of the waste, to reduce the surface area to prevent the transfer of waste contaminants between them, and to limit the mobility of the components when exposed to leaching liquids. Portland cement (PC) is the most commonly used binder for stainless steel from heavy metal-containing waste.
As cement hydration progresses in the S/S process, an interwoven network of minerals envelops the contaminants present in the mud. Because solidified waste has a smaller surface area exposed to the environment and less permeability, the release of heavy metals is reduced. Thus, by immobilizing heavy metals by physical and chemical adsorption, chemical incorporation (ion exchange, surface complexation, precipitation, diodohy) and microencapsulation, mixed cements consisting of PC plus fly ash (PFA) and granulated blast furnace slag are formed. (GGBS) can be used to improve management properties and reduce environmental impact (Quanyuan Chen, 2009).
These are materials used to replace part of the cement to save money or improve it. Furnace bottom ash is created when about 20% of the ash melts into large particles and falls out of the flue gases. The Bogue equations can be used to calculate the approximate proportions of these in the cement.
By comparing the oxide composition of OPC and ES, an excellent foundation is laid for the design of the concrete mix for the upcoming experiment. However, some researches have studied the limitation of TCLP for the evaluation of cement waste due to the high final pH in the leaching solutions, which could prevent the release of heavy metals (Chien-Chih Lu, 2019). See Table 2.5 below for a breakdown of the agency's hazardous waste limits and codes.
Furthermore, table 2.6 showed selected physico-chemical properties of ES as well as TCLP-leachable heavy metal concentrations in the galvanizing sludge sample. From the TCLP reading of the electroplating sludge sample, copper has the highest concentration of all heavy metals detected, which is 652.7 mg/L.
METHODOLOGY
Introduction
Characterisation of Electroplating Sludge
- Moisture Content of Electroplating Sludge
- Preparation of Oven-dried Sludge and Sludge Ash
- Heavy Metal Content of Electroplating Sludge
The mold will be re-weighed once the ash/dried electroplating sludge has been applied. After recording all the mold weight data, the mold was placed in a firing/drying oven for drying. The ash concentration was determined by weighing the ash after a 120-minute incineration at 550 degrees Celsius.
For the dried electroplating sludge, the electroplating sludge was dried using a drying oven at 105 degrees Celsius for 24 hours. After the ash and the dried electroplating sludge were prepared, both samples were crushed into a fine powder by the LA grinding process and subjected to an X-ray fluorescence test, and the components of both samples were analyzed. Toxicity characteristic leaching procedure (TCLP) is used to determine the heavy metal in the electroplating sludge.
Once the sample has been extracted with a microwave digester, which will convert the sample from solid form to liquid form. The sample is then analyzed with a heavy metal analyzer, ICP-OCES (Inductively Coupled Plasma-optical Emission Spectrometer).
Stabilization/ Solidification of Electroplating Sludge
- Compression Test
- Leaching Test of Stabilised Electroplating Sludge
The cube was placed in the compression test device and the cube's failure limit was recorded. The results were then compared to see how galvanic sludge affected the compressive strength of cement mortar. The Toxicity Characteristic Leach Process (TCLP) was used to investigate the leachability of heavy metals in the samples according to EPA Method 1312.
An inductively coupled plasma atomic emission spectrometer (ICP-OES) was used to determine the amounts in the filtrate.
RESULT AND DISCUSSION
- Characteristic of Electroplating Sludge
- Toxic Characteristic Leaching Procedure of Petroleum Sludge Ash and
- Characterization of Electroplating Sludge (ES)
- Compressive Strength of Oven-dried ES and Furnace incinerated ES ash
Based on an XRF study of PSA's oxide content, Table 4.5 shows the oxide composition of both kiln-dried ES and kiln-fired ES ash compared to OPC. Both kiln-dried ES and kiln-fired ES ash exhibited class C ash pozzolanic and partially cementitious properties, according to the percentages of silicon dioxide, SiO2, iron(III) oxide, Fe2O3, and alumina, Al2O3. However, compared to OPC, the level of calcium oxide, CaO, in kiln-dried ES and kiln-fired ES ash was significantly lower at less than 1 percent versus 64 percent in OPC.
The kiln-dried ES and kiln-burned ES ash exhibits pozzolanic properties as evidenced by the calcium oxide percentage, which falls into the Type CI fly ash class. Compared with OPC, the effect of magnesia, MgO and alumina, the Al2O3 concentration has less significant differences, and does not greatly affect the performance of kiln-dried ES and kiln-burned ES ash as a cement replacement material, according to the table . above. Both kiln-dried ES and kiln-burned ES ash had a significantly higher concentration of phosphate, P2O5, than OPC, which had a phosphate value of 0.05 percent.
The amount of iron (III) oxide, Fe2O3, is one of the main determinants of the suitability of kiln-dried ES and kiln-fired ES ash as a cement substitute. The high iron (III) oxide content of kiln-dried and kiln-dried ES ash can be problematic when used in a high proportion, and its performance in cement mortar was determined by encapsulation. The compressive strength of cement mortar with a control sample and various cement replacements with kiln-dried ES and kiln-fired ES ash is shown in the table and graph below.
Compared to the control sample, the 7-day compression showed lower strengths for oven-dried ES and oven-fired ES ash cement for all samples. The early strength gains of kiln-dried ES and kiln-burned ES ash cement mortars were minimal, due to the high sodium oxide and Na2O content of kiln-dried ES and kiln-burned ES ash. As a result, the slow hydration of cement caused by kiln-dried ES and kiln-burned ES ash is undesirable for 7-day compressive strength values.
High iron (III) oxide, Fe2O3 of kiln-dried ES and kiln-fired ES ash caused a loss in compressive strength in D10, D20, D30, A20 and A30. For replacement percentages of 10%, 20% and 30%, a strength activity index study was conducted in cement mortar using kiln-dried ES and kiln-fired ES ash as cement placement materials.
CONCLUSION
Project Outcome
Recommendation
Application of dry composite electroplating sludge in the preparation of cement-based decorative mortar as green pigment. Stabilization of electroplating sludge with iron sludge by thermal treatment by incorporating heavy metals into the spinel phase. Hardening of electroplating sludge with alkali-activated fly ash to prepare a non-burnt brick and its risk assessment.
Effect of carbonation on the acid neutralizing ability of cement and cement hardened/stabilized electroplating sludge. Influence of heavy metals on dicalcium silicate polymorphs in belite-rich clinkers produced from electroplating sludge. Stepwise Extraction of Fe, Al, Ca and Zn: A Green Way to Recycle Raw Electrification Sludge.
APPENDIX B – HEAVY METAL ANALYSIS RAW DATA FOR RAW ES, OVEN-DRIED ES AND FURNACE-COATED ES ASH. APPENDIX C – HEAVY METAL ANALYSIS RAW DATA FOR CEMENT MORTAR OVEN-DRIED ES AND OVEN-BURNED ES ASH.
