Treatment of wood industry wastewater by combined coagulation–flocculation–decantation and fenton process

Abstract

In the present research, the efficiency of turbidity and chemical oxygen demand (COD) reduction from the wood industry wastewater (WIW) by the use of a combined coagulation–flocculation–decantation (CFD) – Fenton process was studied. Firstly, the performance of three coagulants such as ferric chloride (FeCl3), aluminum sulphate (alum), and polyaluminum chloride (PACl) was evaluated. The polyacrylamide (PAM) was used as a flocculant. The results showed that the polyaluminum chloride had a high removal efficiency. The COD reduction of 84.1% and turbidity removal of 82.0% of were obtained in coagulation–flocculation–decantation (CFD). Secondly, Fenton process was optimized, by the use of a response surface methodology (RSM), with application of a central composite design (CCD). The maximum turbidity and COD removal obtained by this process were 94.1% and 72.5% respectively, under optimal conditions ([Fe2+] = 250 mg/L, [H2O2] = 500 mg/L, pH 3.5, time 60 min). The kinetics of COD and turbidity removal were determined by the model of first order. In conclusion, the combination of coagulation–flocculation–decantation (CFD) – Fenton process presented as a remarkable method for wood wastewater treatment. Practitioner points A combination of coagulation–flocculation–decantation and Fenton process was introduced for the wood industry wastewater treatment. A designed experimental approach for treatment of wood industry wastewater using a Fenton process was studied. The yields of COD, BOD5, N‐NO3, P‐PO4, and dye removal were obtained according to the standard limits in Iran.

Introduction of TiO2-[bip]-NH2+ C(NO2)3− as an effective nanocatalyst for the Hantzsch reactions

“…Also, when methyl acetoacetate was used instead of ethyl acetoacetate, the related products were obtained in high yields (Table 2, entries 13-16). use of 1,3cyclohexanedione instead of dimedone under the selected conditions resulted in the requested products with the same efficiency (Table 2, entries [17][18][19][20][21][22]. After considerable results were obtained from the preparation of hexahydroquinolines in the presence of TiO 2 -[bip]-NH 2 + C(NO 2 ) 3 À , we were encouraged to investigate the activity of this catalyst in the reaction between aldehydes (1 mmol), ammonium acetate (1.5 mmol) and dimedone or 1,3-cyclohexanedione (2 mmol), leading to 1,8-dioxodecahydroacridine derivatives.…”

“…18 Due to its availability, high surface area, low cost, and easy preparation, TiO 2 can be considered as one of the best candidates for this purpose. 19,20 Nitro compounds have wide applications as solvents and in chemical industries. The hydrogen atom on the alpha carbon in primary and secondary nitro alkanes is too active to use in chemical reactions.…”

Remediation of Organic Contaminant in Sludge by using Bioaugmentation and Solidification and Stabilization (S/S) Method

“…Wood processing by-products of different forms of polyphenols range from basic monomers to high molecular weight polyphenolic polymers. Lignin, sulfur, chlorinated phenolic, aromatic compounds, resin acids, fatty acids and tannins are compounds in the wood-processing industrial wastewater in which can cause harm and mutagenicity to the environment and living things [8,9]. It is also claimed to have high chemical oxygen demand (COD) and suspended solids content due to a large amount of water used during resin extraction, wood chip cleaning, steam generation, and refinery processes [10].…”

Low cost effective heterogeneous photo‐Fenton catalyst from drinking water treatment residuals for reactive blue 19 degradation: Preparation and characterization

“…Advanced oxidation processes (AOPs) are the most promising methods for degradation of the refractory organic matter through generated reactive and nonselective hydroxyl radical (Andreozzi, Caprio, Insola, & Marotta, 1999; Azimi, Shirini, & Pendashteh, 2020a, 2020b; Deng & Zhao, 2015; Guimarães, Guedes Maniero, & Nogueira de Araújo, 2012). Among them, the Fenton's reagent has demonstrated many advantages, such as low costs and the easiness of implementation (Rodríguez et al, 2016).…”