Sorption of metals and metalloids from reverse osmosis concentrate on drinking water treatment solids

Simultaneous adsorption of Cr(VI) and phenol onto tea waste biomass from binary mixture: Multicomponent adsorption, thermodynamic and kinetic study

“…The composition of tannery 12 waste water is given in Table 1 [4]. Chromium is found in the 13 environment in two oxidation state trivalent [Cr(III)] & hexavalent 14 [Cr(VI)], out of which Cr(VI) is most mutagenic and carcinogenic to 15 the living organism and is usually present in the form of chromate 16 (CrO 4 2À ) or dichromate (Cr 2 O 7 2À ) ions [5]. Cr(III) is toxic to plants at 17 higher concentrations and less toxic to animals or living beings [6].…”

“…According to WHO the 23 maximum permissible limit for Cr(VI) and phenol are 0.05 and 24 1 mg L À1 , respectively [4,9]. There are several methods for the 25 removal of toxic metals and organic compounds [10] such as 26 oxidation-reduction [11], electrocoagulation [12], reverse osmosis 27 [13], evaporation [14] ion exchange [15], photocatalytic oxidation 28 [16,17], bioremediation [18] and electrokinetic remediation [19]. 29 This method causes several problems such as high energy and 30 chemical requirements, low efficiency and produces a large amount 31 of sludge [20].…”

Uptake of Zn2+ and As3+ from Wastewater by Adsorption onto Imine Functionalized Magnetic Nanoparticles

“…At pH values less than the pH pzc , the charges on the surface of the adsorbent are positive which causes a competition for binding on the surface of the adsorbents, this result into a reduction in the removal efficiency of the adsorbent at lower pH values. At pH values greater than the pH pzc , adsorption of positively charged ions is favored as a result of the small amount of positive ions at these pH values which permits ionic interaction between the adsorbent and metal ions [36]. Interestingly, MNP-NH 2 and MNP-Maph showed similar patterns in the adsorption of Zn(II) and As(III) from aqueous solution as pH increases from 1 to 10.…”

Statistical optimization of process parameters for the simultaneous adsorption of Cr(VI) and phenol onto Fe-treated tea waste biomass

“…Precipitation/coagulation (Wang et al 2011), chemical oxidation (Dittert et al 2014), biodegradation (Annadurai et al 2008), adsorption (Jain et al 2011), ion exchange (Cavaco et al 2007), membrane processing (Lin et al 2014), electrolytic methods (Hamdan and El-Naas 2014), carbon nanomaterial (Salam et al 2012), etc. are some important methods which have been used to remove the heavy metal ion and phenolic contents together.…”