The Effect of Leachate on the Hydraulic Conductivity of a Sand Bentonite Mixture

Year 2024, Volume: 26 Issue: 77, 264 - 271, 27.05.2024

Seda Durukan

https://doi.org/10.21205/deufmd.2024267710

Abstract

The permeability behavior of sand-bentonite mixtures which are used as liner, was investigated by using original leachate. In this regard, the flexible wall hydraulic conductivity tests were performed. In literature, the conventional test procedures generally comprise the permeability values of the liners by using tap water, this study suggested determining the hydraulic conductivities under the effect of leachate. Thus, leachate samples were taken from a municipal solid waste site located in the Aegean region. The selected proportion is 10% bentonite as the dry weight for a sand-bentonite mixture. Some chemical analyses were also done for the inlet and outlet leachate samples. It is found that the mixture ensures the hydraulic conductivity criteria for landfill liners while it approaches the critical value. Also, it should be noted that the hydraulic conductivity with leachate was found to be more than that of with tap water. The pH of the environment for each test was found to be basic. The electrical conductivity values for each test were found to be under 1. This situation implies that the cation exchange process was not completed. Finally, some alkaline and alkaline earth metals were measured in both inlet and outlet fluids, changes in the mineral structure of the clay in the mixture under leachate exposure were determined and their effect on the hydraulic conductivity was discussed.

Keywords

Landfill Liner, Sand-Bentonite Mixtures, Leachate, Hydraulic Conductivity

Project Number

2018-060

Kum Bentonit Karışımında Sızıntı Suyunun Hidrolik İletkenliğe Etkisi

Abstract

Bu çalışmada düzenli atık depolama sahaları altında geçirimsiz tabaka olarak da kullanılan kum-bentonit karışımlarının sızıntı suyu karşısındaki geçirimsizlik davranışı incelenmiştir. Bu amaçla kum-bentonit karışımı içerisinden sızıntı suyunun geçirildiği esnek duvarlı hidrolik iletkenlik deneyine tabi tutulmuştur. Literatürde genel olarak musluk suyu ya da yapay kirleticiler ile gerçekleştirilen hidrolik iletkenlik deneyleri, bu çalışmada orijinal sızıntı suyu ile gerçekleştirilmiştir. Sızıntı suyu olarak da Ege Bölgesinden seçilen bir katı atık depolama sahasından elde edilen sızıntı suları kullanılmıştır. Kum-bentonit karışımının oranı kuru ağırlıkça %10 bentonit içerecek şekilde hazırlanmıştır. Deney esnasında sızıntı suyunun giriş ve çıkış sıvılarının bazı kimyasal analizleri de gerçekleştirilmiştir. Ölçülen hidrolik iletkenlik değerlerinin sınır koşullara yakın olmak kaydı ile, kriterleri sağladığı belirlenmiştir. Bununla beraber, musluk suyu sonuçlarına göre artış görüldüğü de dikkati çekmiştir. Ortam pH’ı tüm deneylerde bazik olarak ölçülmüştür. Sızıntı suyuna ait giriş sıvısının elektriksel iletkenliğinin, tüm örneklerin çıkış sıvılarının elektriksel iletkenliğine oranı 1’in altında kalmıştır. Bu durum deneyin sonlandırıldığı anda katyon değişimlerinin sonlanmadığını işaret etmektedir. Son olarak da giriş ve çıkış sıvılarındaki bazı alkali ve toprak alkali metali iyonlarındaki değişimler ölçülmüş, karışımdaki kilin sızıntı suyu maruziyeti altında mineral yapısındaki değişimler belirlenmiş ve hidrolik iletkenliğe etkisi de tartışılarak sunulmuştur.

Keywords

Geçirimsiz Tabaka, Kum Kil Karışımları, Sızıntı Suyu, Hidrolik İletkenlik

Supporting Institution

Manisa Celal Bayar Üniversitesi Bilimsel Araştırma Projeleri Koordinasyon Birimi

Project Number

2018-060

Thanks

Bu çalışma Manisa Celal Bayar Üniversitesi Bilimsel Araştırma Projeleri Koordinasyon Birimi tarafından desteklenmiştir. Proje Numarası: 2018-060. Yazar, Dokuz Eylül Üniversitesi İnşaat Mühendisliği Bölümü Goteknik ABD’a sızıntı suyu temini katkısından dolayı teşekkür eder.

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