Assessment Of Wastewater Treatment Efficiency Of A Constructed Wetland At Finlays Flower Farm, Kericho, Kenya

ABSTRACT

An assessment of wastewater treatment efficiency of Chemirei constructed wetland (CW) at James Finlay's farm in Kericho was carried out from November 2014 to February 2015. Water samples were collected twice per month from seven sampling points (S1-S7) using acid cleaned bottles for analysis. In situ measurements of Dissolved Oxygen (DO), pH, EC and temperature were done using calibrated meters and probes. Wastewater inflow and outflow rates for each purification cell were obtained using the volumetric method. Macrophyte biomass was determined using harvest method. Hydraulic retention time (t) and loading rate (q) were determined using mean flow rate (Q), system volume (V) and wetted surface area (A). In the laboratory; SRP, TP, NH4-N, NO3-N, NO2-N, TN, TSS, BOD and COD were determined using Standard Methods for Analysis of Water and Wastewater (APHA, 2004). Data were checked for normality and homogeneity of variance prior to parametric test. Analysis was done using IBM SPSS statistics 21 (USA) and comparison of means of different wastewater variables were performed using Analysis of Variance (ANOVA). Tukey HSD post hoc test was applied to separate means between the sampling sites where all statistical tests were considered significant at p