title: Impact of diatomite on the slightly polluted algae-containing raw water treatment process using ozone oxidation coupled with polyaluminum chloride coagulation.
abstract: The impact of adding diatomite on the treatment performance of slightly polluted algae-containing raw water using ozone pre-oxidation and polyaluminum chloride (PAC) coagulation was investigated. Results demonstrated that the addition of diatomite is advantageous due to reduction of the PAC dose (58.33%) and improvement of the removal efficiency of algae, turbidity, and dissolved organic matter (DOM) in raw water. When the ozone concentration was 1.0 mg L⁻¹ and the PAC dosage was 2.5 mg L⁻¹, the removal rates of algae, turbidity, UV254, and TOC were improved by 6.39%, 7.06%, 6.76%, and 4.03%, respectively, with the addition of 0.4 g L⁻¹ diatomite. It has been found that the DOM presented in the Pearl River raw water mainly consisted of small molecules (<1 kDa) and large ones (> 50 kDa). After adding diatomite (0.4 g L⁻¹), the additional removal of 5.77% TOC and 14.82% UV254 for small molecules (<1 kDa) of DOM, and 8.62% TOC and 7.33% UV254 for large ones (>50 kDa) could be achieved, respectively, at an ozone concentration of 1.0 mg L⁻¹ and a PAC dose of 2.5 mg L⁻¹. The growth of anabaena flos-aquae (A.F.) was observed by an atomic force microscope (AFM) before and after adding diatomite. AFM images demonstrate that diatomite may have a certain adsorption on A.F.
authors.affiliation: a College of Environment and Energy , South China University of Technology , Guangzhou 510006 , People's Republic of China.
authors.forename: Wenchao
authors.initials: W
authors.lastname: Hu
authors.forename: Chunde
authors.initials: C
authors.lastname: Wu
authors.forename: Aiyin
authors.initials: A
authors.lastname: Jia
authors.forename: Zhilin
authors.initials: Z
authors.lastname: Zhang
authors.forename: Fang
authors.initials: F
authors.lastname: Chen
mesh_terms: D000536:Aluminum Hydroxide / Q000737:chemistry*; D007692:Diatomaceous Earth / Q000737:chemistry*; D046869:Dolichospermum flos-aquae / Q000737:chemistry*; D005427:Flocculation; D008567:Membranes, Artificial; D018625:Microscopy, Atomic Force; D009391:Nephelometry and Turbidimetry; D016877:Oxidants / Q000737:chemistry*; D010084:Oxidation-Reduction; D010126:Ozone / Q000737:chemistry*; D014462:Ultrafiltration; D014873:Water Pollutants / Q000737:chemistry*; D018508:Water Purification / Q000295:instrumentation / Q000379:methods
chemical_list: D008567:Membranes, Artificial; D016877:Oxidants; D014873:Water Pollutants; C016213:aluminum oxychloride; D000536:Aluminum Hydroxide; D007692:Diatomaceous Earth; D010126:Ozone; C033787:diatomite
keywords: algae; diatomite; dissolved organic matter; enhanced coagulation; removal