**4.2 Effect of vermifilter and control biofilter on total dissolved solids in sewage water**

The study reveals that the vermifilter and control biofilter significantly treated the TDS from the domestic sewage (**Figure 2**). The TDS level of treated sewage showed no significance difference in the VF and CF. The VF shows an efficiency of 44–90% and in the CF it was 70–93% (**Figure 2**).

Bars shown using different letters were significantly different at 5% level of significance. The vertical bars shown at the top of each bar show the standard error of difference of means.

**Figure 1.** *Turbidity of influent and effluent.*

**Figure 2.** *TDS of influent and effluent.*

### **4.3 Effect of vermifilter and control biofilter on total suspended solids of sewage water**

There was a significant difference in the level of TSS in the untreated sewage and the treated sewage from the two biofilters. The two biofilters had no significant difference in their operation of removing total suspended solids. The percentage reduction in TSS was higher in the VF at 48–97% and 24–97% in the CF (**Figure 3**).

Bars shown using different letters were significantly different at 5% level of significance.

The vertical bars shown at the top of each bar show the standard error of difference of means.

## **4.4 Efficiency of vermifilter and control filter in treating total coliforms in domestic sewage**

The vermifilter and control efficiently treat the available total coliforms in untreated sewage. The total coliforms in untreated sewage were significantly different from total coliforms from the two filters. The VF and CF, however, did not have any significant difference in their treatment porosity. The percentage reduction in the VF was 78–98% whilst in the CF it was 97–98% (**Table 4**).

Septic tank effluent did not meet the required EMA SI6 Standards for disposal into the environment. Both filters were effective in treating domestic sewage. There was significant difference between untreated and treated wastewater on selected physico-chemical and microbiological parameters. Vermifilters and control significantly (p < 0.01) treated the physico-chemical (pH, turbidity, TDS, TSS, BOD, nitrates, phosphates) and microbiological (total coliforms) properties of domestic sewage water.

**Figure 3.** *TSS in influent and effluents.*


### **Table 4.**

*Analysis of variance on the efficiency in total coliform removal of a vermifilter and control filter in treating domestic sewage.*
