Textile dyeing wastewater negatively influences the hematological profile and reproductive health of male Swiss albino mice

Objective:To determine the effects of textile dyeing industrial wastewater on the hematological parameters and reproductive health including histoarchitecture of male gonad(testes)of mice.Methods:Twenty-four Swiss albino mice at 4-weeks old were divided into four groups(n=6 per group).Mice of group 1 supplied with normal drinking water were served as the control group.Mice of group 2,3 and 4 were supplied normal drinking water mixed with textile dyeing wastewater at 5%,10% and 20% concentration,respectively.After completing 24 weeks of treatment,different hematological profile,weight of testes,gonadosomatic index(GSI),sperm concentration and morphology were measured.Moreover,histopathological changes in testes were examined.Results:Hematocrit value and hemoglobin concentrations were decreased in all groups of wastewater-treated mice compared to the control group.Likewise,weight of testes,GSI and sperm concentration were decreased significantly in wastewater-treated mice in comparison to the control group.The percentage of morphologically healthy epididymal sperm was significantly reduced in wastewater-treated mice.Histopathological examination revealed degenerative changes in seminiferous tubules,a smaller number of spermatogenic cells,elongation of seminiferous tubules and degenerative changes of seminiferous tubules in wastewater-treated mice.Conclusions:Textile dyeing wastewater has harmful effects on hematological profile and reproductive health of male mice.

Photocatalytic degradation of textile dyeing wastewater through microwave synthesized Zr-AC,Ni-AC and Zn-AC

The novel zirconium oxide, nickel oxide and zinc oxide nanoparticles supported activated carbons（Zr-AC, Ni-AC, Zn-AC） were successfully fabricated through microwave irradiation method. The synthesized nanoparticles were characterized using XRD, HR-SEM, XPS and BET. The optical properties of Zr-AC, Ni-AC and Zn-AC composites were investigated using UV–Vis diffuse reflectance spectroscopy. The photocatalytic efficiency was verified in the degradation of textile dyeing wastewater（TDW） in UV light irradiation. The chemical oxygen demand（COD） of TDW was observed at regular intervals to calculate the removal rate of COD. Zn-AC composites showed impressive photocatalytic enrichment, which can be ascribed to the enhanced absorbance in the UV light region, the effective adsorptive capacity to dye molecules, the assisted charge transfer and the inhibited recombination of electron-hole pairs. The maximum TDW degradation（82% COD removal） was achieved with Zn-AC. A possible synergy mechanism on the surface of Zn-AC was also designed. Zn-AC could be reused five times without exceptional loss of its activity.

Preparation of Ce-TiO_(2)-RGO catalyst and its application in the treatment of printing and dyeing wastewater

Ce-TiO_(2)-RGO composite photocatalyst was prepared by sol-gel method and ultrasonic treatment.The effect of Ce doping mass fraction on the degradation of textile printing and dyeing wastewater was studied.The catalysts were characterized by XRD,SEM,TEM,UV-vis and PL.The results showed that,Ce-TiO_(2)particles uniformly adsorbed on the GO surface,and the particle diameter of Ce-TiO_(2)was approximately 25-110 nm.After Ce doping,the absorption band edge of TiO_(2)-RGO composite photocatalyst was redshifted and the band gap was reduced.With the increase of Ce doping mass fraction,the PL intensity of Ce-TiO_(2)-RGO composite photocatalyst first decreased and then slightly increased,and the emission peak intensity of 6%Ce-TiO_(2)-RGO composite photocatalyst was the lowest at 410 nm and 470 nm.Taking textile printing and dyeing wastewater as the research object of degradation,the COD removal rate of 6%Ce-TiO_(2)-RGO reached the maximum of 82.21%at 180 min,and the COD value after degradation was 88.95 mg/L which was in line with the wastewater discharge standard.On the other hand,at 180 min,the degradation rate for textile printing and dyeing wastewater by 6%Ce-TiO_(2)-RGO also reached the maximum(99.21%).Therefore,the Ce-TiO_(2)-RGO composite photocatalyst showed great application potential in the treatment of textile dyeing wastewater.

Removal of C.I.Reactive Red 2 by low pressure UV/chlorine advanced oxidation

Azo dyes are commonly found as pollutants in wastewater from the textile industry,and can cause environmental problems because of their color and toxicity.The removal of a typical azo dye named C.I.Reactive Red 2（RR2） during low pressure ultraviolet（UV）/chlorine oxidation was investigated in this study.UV irradiation at 254 nm and addition of free chlorine provided much higher removal rates of RR2 and color than UV irradiation or chlorination alone.Increasing the free chlorine dose enhanced the removal efficiency of RR2 and color by UV/chlorine oxidation.Experiments performed with nitrobenzene（NB）or benzoic acid（BA） as scavengers showed that radicals（especially OH） formed during UV/chlorine oxidation are important in the RR2 removal.Addition of HCO_3^- and Cl^- to the RR2 solution did not inhibit the removal of RR2 during UV/chlorine oxidation.