การศึกษากระบวนการหล่อแข็งโลหะไฮดรอกไซด์โดยใช้ปูนซีเมนต์

A Study of Solidification Systems for Heavy Metal Hydroxides Using Ordinary Protland Cement

Name: มานพ บุญแจ่ม

Name: Manop Boonjam

Organization : มหาวิทยาลัยเทคโนโลยีพระจอมเกล้าธนบุรี. คณะพลังงานสิ่งแวดล้อมและวัสดุ. สาขาวิชาเทคโนโลยีสิ่งแวดล้อม

keyword: โลหะ

; ปูนซีเมนต์ปอร์ตแลนด์

Abstract: This research was conducted to investigate the solidification processes of heavy metalhydroxides using Ordinary Portland Cement (OPC) as solidification binder. Synthetic Pb and Crhydroxide were used at 10, 20 and 30 wt.% and a w/s ratio of 0.45 was used throughout thisworkAddition of Cr hydroxides at 10, 20 and 30 wt.% resulted in an increase final settingtime from 4 to 5 ,6.25 and 7.5 hours, respectively. The final setting time increased to 77 and 99hours when 10 and 20 wt.% Pb hydroxides were added, respectively. In addition, the final settingof OPC mixes with 30 wt.% of Pb hydroxide was not observed within 150 hoursHigh concentration of Pb ions was found in cement solution during OPC hydration.This is because the amphoteric Pb hydroxide was resolubilized in the highly alkalineenvironment of cement. It is observed that the concentration of Cr ions in cement solution waslower than Pb ions. It could be possible that Cr ions was incorporated into the cement matrix.The concentration of ca2+ and SO:- ions in OPC/Cr and OPCPb systems decreased withincreasing hydration time but at a lower rate than that of the control.Unconfined compressive strength of cement paste increased with increasing curingduration. Experimental results showed that compressive strength of cement paste at the age of 8 dayswas 244.4 kg./cm2 and increased to 349.4 , 427.6 and 441.9 kg./cm2 after 29 , 56 and 91 days,respectively. In addition, a reduction in compressive strength of the solidified wastes at eachcuring duration was observed when metal hydroxides were added and the rate of strengthdevelopment decreased with increasing concentration of metal hydroxides in the mixes.Leaching of Pb and Cr hydroxides from the solidified wastes was depended on leachatepHs. The difference between leachate pHs and minimum solubility of Pb hydroxide was higherthan that of Cr-hydroxide and as a result Pb was leached at a higher rate than Cr. In addition,leachability of metal hydroxides increased with increasing intial concentration of metalhydroxides in the mixes.Durability of solidified wastes against acid corrosion was in the following order :sulfiu-ic acid > acetic acid > nitric acid. Durability of the solidified wastes against wet-dry cyclewas also observed to be lower than that of cement paste. It was noticed that the solidified wasteswere less durable to aggressive environmental condition when metal hydroxide concentration inthe mixes was increased

มหาวิทยาลัยเทคโนโลยีพระจอมเกล้าธนบุรี. สำนักหอสมุด

Address: กรุงเทพมหานคร

Email: info.lib@mail.kmutt.ac.th

Name: สุวิมล อัศวพิศิษฐ

Role: อาจารย์ที่ปรึกษา

Created: 2544

Issued: 2008-01-18

Modified: 2554-07-14

วิทยานิพนธ์/Thesis

CallNumber: EV260

tha

DegreeName: วิทยาศาสตรมหาบัณฑิต

Level: ปริญญาโท

Descipline: เทคโนโลยีสิ่งแวดล้อม

Grantor: มหาวิทยาลัยเทคโนโลยีพระจอมเกล้าธนบุรี

©copyrights มหาวิทยาลัยเทคโนโลยีพระจอมเกล้าธนบุรี

ลำดับที่.	ชื่อแฟ้มข้อมูล	ขนาดแฟ้มข้อมูล	จำนวนเข้าถึง	วัน-เวลาเข้าถึงล่าสุด
1	EV260ab.pdf	38.44 KB	12	2018-05-10 19:05:53
2	EV260ab.txt	2.78 KB	7	2018-05-10 19:05:55
3	EV260.pdf	1.39 MB	8	2020-07-02 11:37:23

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