Contents lists available at ScienceDirect Journal of Environmental Chemical Engineering journal homepage: www.elsevier.com/locate/jece Fluidized aerobic bio-reactor technology in treatment of textile efuent P.U. Singare Department of Chemistry, Bhavan’s College, Munshi Nagar, Andheri (West), Mumbai, 400058, India ARTICLEINFO Keywords: Heavy metals Industrial pollution Physico-chemical parameters Removal efciency ABSTRACT Thepresentstudyhighlightstheefciencyof fuidized aerobic bio-reactor based technology fortreatmentofthe textile efuent. The percentage treatment efciencyofCOD(93%),totalsuspendedsolids(72%),totaldissolved solids (94%), BOD (88%), pH (25%), alkalinity (98%), electrical conductivity (51%), hardness (99%), chlorides (33%), Cu 2+ (95%), Cr 6+ (49%), Pb 2+ (75%), Fe 3+ (96%) and Zn 2+ (91%) achieved in the present study was better than or comparable with that reported by using advanced treatment technique. The level of pH (6.97), total dissolved solids (357.63mgL −1 ), COD (136.95mgL −1 ), Cu 2+ (1.06mgL −1 ), Cr 6+ (0.67mgL −1 ), Fe 3+ (1.14mgL −1 ), Zn 2+ (0.47mgL −1 ) in the treated efuent was within the limits of FEPA, CCME, CPCB, USEPA and BIS standards. The level of dissolved oxygen (7.16mgL −1 ) was above the minimum level of 4.0mgL −1 requiredfortheexistenceofaquaticlifeintheinlandsurfacewater.However,thelevelofelectricalconductivity (7288 μS cm −1 ), chlorides (1340mgL −1 ), phosphates (7.49mgL −1 ), total suspended solids (328.50mgL −1 ), BOD (57.25mgL −1 ) and Cu 2+ (1.06mgL −1 ) were exceeding the above limits. It is expected that the present efuent treatment technology will help in the treatment and recycling of textile industry efuent for further use thereby reducing the wastage of fresh/potable water for textile processing which in turn will reduce the in- dustrial expenditure on water procurement. 1. Introduction Textile industry is one of the rapidly developing and largest orga- nized industrial sectors in India. There are about 7000 large-scale tex- tile industries situated in Gujarat, Maharashtra, Rajasthan and Tamil Nadustates.Amongthetextileindustries,wetfabricindustriesgenerate a large amount of liquid efuents, and the amount of water used and discharged from the these industries depends upon the desizing, scouring, bleaching, mercerizing, dyeing, printing and fnishing op- erational processes. With respect to the impact of textile industries on the environment at global level, it is estimated that in comparison to any other industrial sector, the textile processing industries consumes more water which about 200L kg −1 of fabric day −1 [1,2 and the ef- fuentreleasedisheavilypollutedcontainingtoxicchemicalslikeacids, alkalis, dyes, hydrogen peroxide, starch, surfactants dispersing agents andsoapsofmetals[3].AccordingtothereportoftheWorldBank,itis estimated that about 17–20 % of efuent water is released during the dyeing and fnishing process of the fabric [2]. To meet the increasing demand for cotton and polyester fabrics, the Indian textile uses about 80% of the overall 1, 30,000tons of manufactured dye global [4]. The textile industrial efuent has high BOD/COD ratio, salt content intermsoftotaldissolvedsolidsandisheavilypollutedduetopresence of reactive dyes which can never be treated by biological method. In ordertoreducethecostofefuenttreatment,itisusuallydischargedin the river creating in the environmental imbalance. The dyes present in the efuent water not only great impact on plant photosynthesis but also impacts the aquatic life reducing the sunlight penetration and by reducing the oxygen consumption. The suspended particles of the ef- fuentmayalsohavetheharmfulefects on certain formsofaquaticlife due to the occurrence of metallic component and chlorine. Suspended particlescanalsokillthefsherybyblockingtheirgills.Theyalsoretard the algal capacity of producing oxygen and food. Previous studies have reported that the dyes released in the efuent create hindrance to municipal efuent treatment by UV decontamination technique [5]. Therefore, many economical and efcient efuent treatment technol- ogies like including physical, chemical, biochemical, hybrid treatment processes are standardized in order to ensure their safe discharge into a river [6]. Previous researchers have adopted various ETP techniques like ad- sorption using saw dust, powdered algal biomass, aquatic and non aquatic plants as adsorbent, rice husk as a biosorbent, soil aquifer treatment [7–11]; TiO 2 dosage coupled with photocatalytic method [12]; coagulation and focculation method using FeCl 3 , poly aluminum chloride, ferrous sulphate, poly-electrolyte, lime and alum as coagu- lants [13–16]; oxidation techniques like wet air oxidation, chemical oxidation using hypo chloride and peroxide, catalytic oxidation, https://doi.org/10.1016/j.jece.2019.102899 Received 26 October 2018; Received in revised form 11 December 2018; Accepted 7 January 2019 E-mail address: pravin.singare@bhavans.ac.in. Journal of Environmental Chemical Engineering 7 (2019) 102899 Available online 08 January 2019 2213-3437/ © 2019 Elsevier Ltd. All rights reserved. T