Practical Approach for Removal of Natural Organic Matter and defluoridation of Maji ya Chai river Water: Use of Acid Pre-treated Bone Char and Coagulants

Abstract

The removal of natural organic matter (NOM) and fluoride from Maji ya Chai River water (MCRW) using bone char (BC) and coagulants was investigated. Fine BC particles ranging from 0.045 to 0.2 mm were used in a 1 litre half-filled container, stirred at 300 rpm for 60 min followed by addition of a commercial coagulant and allowed to settle for 24 hours to remove NOM. MCRW practicable and affordable defluoridation method for removal of NOM through defluoridation with BC pre-treated with 0.3 N HCl followed by coagulation with Poly-aluminium chloride (PACl) is proposed. Reduction of fluoride from 21 mg/L to 1.7 mg/L was achieved by use of 5 g/L of 0.3 N HCl acid pre-treated BC and 66 mL of 1% PACl per litre of MCRW. The acid pre-treated BC was found to double defluoridation capacity of BC, while adjustment of pH of MCRW with HCl acid to pH 3 has tripled defluoridation capacity of BC. The 0.3 N HCl acid pre-treated BC is preferred to avoid impractical working with acid solution for pH adjustment in households and communities. The treated water pH was within the acceptable portable water range of 6.5 to 8.5. PACl is a preferable coagulant for removal of NOM from MCRW since it is more effective and safer compared to use of alum and zetafloc 703.

Inorganic arsenic species removal from water using bone char: A detailed study on adsorption kinetic and isotherm models using error functions analysis

“…Waste-based adsorbents from the meat industry, such as bone char, can be a potential solution for the contamination problem. Bone char has been reported to be an excellent adsorbent for fluoride ions (F -) removal from water and discoloration in the sugar industry (Minja, 2020;Nigri et al, 2019). However, there are limited studies examined the use of bone char for As(V) removal (Alkurdi et al, 2019b) and not known studies for the removal of As(III) due to its less amenability to adsorption at natural pH range of groundwater where As(III) species are neutral (Zeltner, 2002).…”

Evaluation of Chemical Compounds and their Relationship to the Breaking Point after adding Chlorine to Water

“…This method has demonstrated its ability to remove solids and many elements. Recently, poly Aluminium Chloride (PACL) has been used which has proven to be very effective in this field [20].…”