**6. Conclusions**

reduce the number of pathogens and indicator organisms [57,58]. In a study by Zhang et al. investigating microorganism concentration in raw sewage, the bacterial indicators total and fecal coliforms were enumerated. The average concentrations of total and fecal coliforms were

CFU/100 ml, respectively [59].

In the last a few years, researchers have reported higher fecal coliform populations, on a dry solids basis, in centrifugally dewatered bio solids compared to digester effluents [60–67]. Therefore, landfill irrigation by leachate water may represent a key process for landfill

Tables 4 and 5 show the microbial density at the plots. As shown in Table 4, the density of fecal and total coliforms increased with the use of leachate water, with almost equal amounts between landfill and clean areas, which suggests that leachate water irrigation is an effective method of landfill remediation. The effects of the plants were also examined, as shown in Table 5. The types of plants affected the amount of fecal coliforms, with the highest concentration in

> **Fecal coliform bacteria (Count per gram)**

Data analyzed using Duncan's multiple range test. *b* maximum value, *ab* intermediate value, *a* minimum value. Alpha =

Data analyzed using Duncan's multiple range test. *b* maximum value; *ab* intermediate value, *a* minimum value. Alpha =

**Fecal coliform bacteria (count per gram)**

**Total coliforms (CFU per gram)**

).

Clean area + tap water 3.2 ×102 *a* 2.1×105 *a* Clean area + leachate water 1.0×103 *b* 7.4×105 *b* Landfill + leachate water 1.0×103 *b* 5.0×105 *ab*

**Table 4.** Changes in fecal coliform bacteria and total coliform density in soil for different factors

**Table 5.** Changes in fecal coliform bacterial density in the soil with different plant species

*M. officinalis* 6.0×102 *a A. rosea* 8.6×103 *b C. dactylon* 1.0×103 *ab*

2.5 ×107

**Factors**

0.05

**Plots**

0.05

CFU/100 ml and 9.6×106

240 Advances in Bioremediation of Wastewater and Polluted Soil

remediation and rehabilitation.

the area planted with *A. rosea* (8.6 ×103

Solid waste landfill sites pose a significant hazard to natural life, and mitigation of these harmful effects has posed a major challenge. This study proved that the use of leachate wastewater for plant breeding on a landfill in drought weather conditions caused a change in microbial activity in the landfill cover soil. If leachate is used for irrigation, the site should be safely enclosed by fencing, given the negative microbial effect on human health.

Landfill rehabilitation has a positive effect on the landscape. In today's world, waste reduction is critically important, as is the need to ensure that people are able to live in a healthy and beautiful environment. The transformation of brownfield areas into healthy green landscapes using recycled wastewater is an area of research that should be a primary focus of scientists.

This paper examines reasons for considering the use of plant remediation for microbial pollution in landfills. These areas offer the potential for improving biodiversity, and turning these problem areas into opportunities requires the selection of the appropriate plants and the most effective technique. The re-vegetation of landfills can increase biodiversity as well as reduce microbial pollution. This article provides an example of such a strategy for landfills in the Mediterranean climate zone.
