Abstract:
Pooraccess toadequate, clean, andsafewaterisoneofthegreatestworldproblemspeopleencounter.Therehasbeenconsiderable
attention in recenttimestowardtheuseofnaturalcoagulantsforwatertreatment.Thisstudyseekstopromotethisbyinvestigating
the potential of Elephantorrhiza goetzei (E. goetzei) seed extract as natural coagulants for water treatment. This included the
determinationofkeyingredientsresponsibleforthecoagulationprocessandoptimaldosagesfortheremovalofturbidity,fluoride,
manganese, and iron. The residual content of organic matter in the treated water and the quality of sludge produced were also
investigated. The methodology consisted of a proximate analysis procedure to investigate the active ingredient(s) responsible for
coagulation and standard jar tests. Standard methods were used for the analyses. Coagulant dosages ranging from 0 to 300 mg/L
at a rapid mixing speed of 120 rpm for 1 min, a slow mixing speed of 30 rpm for 15 min, and a settling time of 15 min were used for
the jar test. The analysis of variance (ANOVA) using IBM SPSS Version 20 was conducted, and regression models were developed
to determine the effect of coagulant dosage on turbidity, pH, total dissolved solids, fluoride, iron, manganese, chemical oxygen
demand (COD), nitrogen, and phosphorus. The results obtained from the proximate analysis of E. goetzei seed extract show that
values of 5.25%, 21.40%, 8.23%, 32.99%, 2.20%, and 29.93% were obtained for moisture, crude protein, crude fiber, fat, ash, and
carbohydrate content, respectively. Moreover, seed extract of E. goetzei achieved removal efficiencies up to 94.8%, 50.1%, 90.0%,
and53.9%forturbidity, fluoride, iron, and manganese in water, respectively. The coagulant has the potential to achieve the desired
World Health Organization (WHO) drinking water standards for turbidity, fluoride, iron, and manganese. The COD increased
from 55.3 to 419.3 mg/L as the coagulant dosage increased from 0 to 100 mg/L. This could cause an unwanted rise in microbial
activities, affecting the microbiological quality of the treated water. The total nitrogen and phosphorus concentrations obtained
in the sludge at 100 mg/L were 0.343 and 0.194 µg/kg, respectively, and this compromises its attractiveness for agricultural reuse
purposes.
