Dissolved organic matter removal using magnetic anion exchange resin treatment on biological effluent of textile dyeing wastewater

This study investigated the removal of dissolved organic matter（DOM） from real dyeing bio-treatment effluents（DBEs） with the use of a novel magnetic anion exchange resin（NDMP）.DOMs in two typical DBEs were fractionized using DAX-8/XAD-4 resin and ultrafiltration membranes. The hydrophilic fractions and the low molecular weight（MW）（〈3 kDa） DOM fractions constituted a major portion（〉50%） of DOMs for the two effluents. The hydrophilic and low MW fractions of both effluents were the greatest contributors of specific UV254absorbance（SUVA254）,and the SUVA254 of DOM fractions decreased with hydrophobicity and MW. Two DBEs exhibited acute and chronic biotoxicities. Both acute and chronic toxicities of DOM fractions increased linearly with the increase of SUVA254 value. Kinetics of dissolved organic carbon（DOC） removal via NDMP treatment was performed by comparing it with that of particle active carbon（PAC）. Results indicated that the removal of DOC from DBEs via NDMP was 60%,whereas DOC removals by PAC were lower than 15%. Acidic organics could be significantly removed with the use of NDMP. DOM with large MW in DBE could be removed significantly by using the same means. Removal efficiency of NDMP for DOM decreased with the decrease of MW. Compared with PAC,NDMP could significantly reduce the acute and chronic bio-toxicities of DBEs. NaCl/NaOH mixture regenerants,with selected concentrations of 10% NaCl（m/m）/1%NaOH（m/m）,could improve desorption efficiency.

Removal efficiencies of natural and synthetic progesterones in hospital wastewater treated by different disinfection processes

Progesterones are ubiquitous in hospital wastewater(HWW)with concentrations much higher than those of estrogens and androgens.To ensure that these water systems are safe to use,disinfection is crucial during HWW treatment by providing"front line"defense against biological contaminations.Here,five disinfection processes,namely,chlorine(Cl_(2)),chlorine dioxide(ClO_(2)),ozone(O_(3)),ultraviolet(UV)),and UV/chlorine(UV/Cl_(2)),were selected to investigate their removal efficiencies for progesterones in primary filtration and secondary biological treatment effluents.There were 61 natural and synthetic progesterones detected in HWW,with the natural progesterones being the main components with a concentration of 845.51 ng/L and contributing to 75.08%of the total proge-sterones.The primary filtration treatment presented insignificant removal effects on the progesterones,while the secondary biological treatment significantly reduced the progesterone content by biode-gradation.The order of removal efficiencies of total progesterones by different disinfection processes was UV/Cl_(2)>Cl_(2)>O_(3)>ClO_(2)>UV.UV/Cl_(2)showed the highest removal efficiency against progesterones mainly due to the activation of Cl_(2)by ultraviolet(UV)photolysis,which helps open the heterocyclic,aromatic,and phenolic rings,thus accelerating progesterone degradation.In addition,the removal efficiencies of natural progesterones in the five disinfection processes were higher than those of synthetic progesterones(progesterone derivatives,19-nortestosterone derivatives,and 17α-hydroxyprogesterone derivatives).