Publication: Effect of compaction on physical properties of a sewage sludge and red gypsum mixture as intermediate landfill cover
Date
2021
Authors
Rosli N.A.
Aziz H.A.
Selamat M.R.
Lim L.L.P.
Zawawi M.H.
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier Ltd
Abstract
This paper investigates the response of sewage sludge and red gypsum mixture under different compaction degree conditions in terms of hydraulic conductivity and unconfined compressive strength (UCS). The UCS and hydraulic conductivity assessments were undertaken using UCS machine and column test using the constant head method, respectively. Five samples were compacted to various degree of compaction (60, 70, 75, 80 and 85%) and percolated with distilled water for six months. The leachate samples from the column test were collected and analyzed at pre-determined days of 1, 3, 7, 14, 28, 42, 56, 75, 90, 120, 150 and 180. The UCS of samples increased with increasing degree of compaction, attributed to the increased number of contact and interparticle interaction between the particles. The degree of compaction appears to affect the initial hydraulic conductivity for the first three days of the experiment, however, gradually stabilize at 10-6 cm/s after 75 days for all samples. The concentration of leached metals and chemical oxygen demand (COD) is below the regulated limit that could affect the environment. The recommended degree of compaction is beyond 80% to achieve the required compressive strength of 345 kPa. � 2021 Elsevier Ltd
Description
Chemical oxygen demand; Compaction; Compressive strength; Granular materials; Gypsum; Leachate treatment; Mixtures; Sewage sludge; Column test; Compaction degree; Constant head; Degree conditions; Degree of compaction; Landfill covers; Property; Red gypsum; Unconfined compressive strength; Wastes recycling; Hydraulic conductivity