**4. Microbial soil analysis**

Over the2-yearstudy period, plants were irrigated with tap water and landfill leachate water during drought conditions (May to September). The landfill leachate water was taken from the collection basin of the Adana Sofulu landfill site. Tables 2 and 3 show the physiochemical, biological and microbial characteristics of landfill leachate water used for the irrigation.

There are three groups of coliform bacteria. Each is an indicator of water and soil quality, and each has a different level of risk. Total coliforms are a large collection of different kinds of bacteria. Fecal coliforms are types of total coliforms that exist in feces, and *Escherichia coli* is a subgroup of fecal coliforms. Total coliform bacteria are common in the environment (soil or vegetation) and are generally harmless [45].

Landfill leachate water showed high concentrations of nitrogen, phosphate and minerals at pH values of 7.9–8.4, and therefore, chemical oxygen demand (COD) and biochemical oxygen demand (BOD) were high, suggesting that landfill irrigation with leachate water may enhance microbial concentration. Microbial density at the plots was thus examined, and these charac‐ teristics were analyzed according to standard methods[46].


*COD* chemical oxygen demand, *BOD* biochemical oxygen demand

**Table 2.** Landfill leachate water properties [8, 36]

Soil samples were collected from three locations within each treatment parcel and mixed. The soil was used for analysis of fecal total coliforms and fecal coliform bacteria. Each soil sample was mixed with sterile water or physiological saline and divided into three subsamples. A membrane filter technique was used for all bacteriological assays [47]. Microorganisms containing thermo tolerant fecal coliforms transferred onto the membrane were incubated on fecal coliform (M-FC, Difco Laboratories, Inc.) agar medium for 24 h at 44.5 °C, and the number of colonies was counted. In the case of *E.coli*, the cells transferred onto the membrane were incubated in M-FC agar medium containing 4-methylumbelliferyl-β-D-glucuronide for 4 h at


**Table 3.** Landfill leachate water microbial properties [8, 36]

**4. Microbial soil analysis**

238 Advances in Bioremediation of Wastewater and Polluted Soil

vegetation) and are generally harmless [45].

**1st year**

**Parameters July**

teristics were analyzed according to standard methods[46].

*COD* chemical oxygen demand, *BOD* biochemical oxygen demand

**Table 2.** Landfill leachate water properties [8, 36]

**August 1st year**

Over the2-yearstudy period, plants were irrigated with tap water and landfill leachate water during drought conditions (May to September). The landfill leachate water was taken from the collection basin of the Adana Sofulu landfill site. Tables 2 and 3 show the physiochemical, biological and microbial characteristics of landfill leachate water used for the irrigation.

There are three groups of coliform bacteria. Each is an indicator of water and soil quality, and each has a different level of risk. Total coliforms are a large collection of different kinds of bacteria. Fecal coliforms are types of total coliforms that exist in feces, and *Escherichia coli* is a subgroup of fecal coliforms. Total coliform bacteria are common in the environment (soil or

Landfill leachate water showed high concentrations of nitrogen, phosphate and minerals at pH values of 7.9–8.4, and therefore, chemical oxygen demand (COD) and biochemical oxygen demand (BOD) were high, suggesting that landfill irrigation with leachate water may enhance microbial concentration. Microbial density at the plots was thus examined, and these charac‐

> **June 2nd year**

**July 2nd year** **August 2nd year**

**May 2nd year**

COD (mg/l) 960 3750 4315 3100 3585 4060 BOD(mg/l) 552 1950 52 47 50 41 pH 8.2 7.9 8.0 8.3 8.1 8.44 NO2-N (mg/l) - - 1.6 2.54 0.40 0.37 PO4-P (mg/l) - - 2.832 7.560 4.880 5.284 Zn (mg/l) 0.2 0.4 0.06 0.04 0.02 0.07 Fe (mg/l) 0.8 1.4 3.5 2.6 0.868 15.2

Soil samples were collected from three locations within each treatment parcel and mixed. The soil was used for analysis of fecal total coliforms and fecal coliform bacteria. Each soil sample was mixed with sterile water or physiological saline and divided into three subsamples. A membrane filter technique was used for all bacteriological assays [47]. Microorganisms containing thermo tolerant fecal coliforms transferred onto the membrane were incubated on fecal coliform (M-FC, Difco Laboratories, Inc.) agar medium for 24 h at 44.5 °C, and the number of colonies was counted. In the case of *E.coli*, the cells transferred onto the membrane were incubated in M-FC agar medium containing 4-methylumbelliferyl-β-D-glucuronide for 4 h at

35 °C. The colonies generating blue fluorescence by exposure to a longwave UV light (366 nm) were counted as *E. coli* cells. The minimum indication level was approximately 30colonyforming units (CFU)/ml, whereas the maximum cutoff level was 300 CFU/ml.

The mean values were compared between groups using one-way ANOVA. A significance level of *P*<0.05 was used throughout the study. The SPSS Version 10.0 software program [48] was used for these statistical analyses. Duncan's multiple range test was applied to bacterial count data.
