Controlling micropollutants in tertiary municipal wastewater by O3/H2O2, granular biofiltration and UV254/H2O2 for potable reuse applications.

A comprehensive pilot study was carried out to experimentally assess the potential of newly developed treatment trains integrating two-stage AOPs and biofiltration to reach potable reuse water quality standards from municipal wastewater. The processes consisted of a two-stage AOPs with (carbon or limestone) biofiltration, the first AOP (O3/H2O2) serving as pre-treatment to biofiltration and the second AOP (UV254/H2O2) serving as post-biofiltration finishing step to ensure advanced disinfection. A comprehensive monitoring campaign was put in place resulting from the combination of targeted, non-targeted and suspect screening measurements. It was found that 13 organic micropollutants were detected from a list of 219 suspects although at ng/L level only. For the treatment conditions piloted in this study (O3 = 13 ±â€¯0.5 mg/L, H2O2 = 11 ±â€¯0.4 mg/L for the O3/H2O2 process, and UV = 410 ±â€¯63.5 mJ/cm2, H2O2 = 5 mg/l for the UV254/H2O2 process), it was possible to estimate the overall removal efficacy for each unit process, which was found to follow this order: RO (99%)  > BAC (87%) > O3-H2O2 (78%)  > BAL (67%)  > UV/H2O2 (43%)  > AOP contact chamber (19%)  > UF(0%), with the treatment train integrating two AOPs and granular biofiltration with activated carbon (O3/H2O2 + BAC + UV254/H2O2) showing superior performance with a 99% abatement in total micropollutants. No ecotoxicologically-positive response was generally observed for any of the effluent samples from the tested trains, even when pre-concentration factors up to 100-1000 times were employed to increase the sensitivity of the bioassay methods.

Combined physico-chemical treatment of secondary settled municipal wastewater in a multifunctional reactor.

In this paper, the physico-chemical treatment of municipal wastewater for the simultaneous removal of pollutant indicators (chemical oxygen demand (COD) and total coliforms) and organic contaminants (total phenols) was investigated and assessed. A secondary settled effluent was subjected to coagulation, disinfection and absorption in a multifunctional reactor by dosing, simultaneously, aluminum polychloride (dose range: 0-150 µL/L), natural zeolites (dose range: 0-150 mg/L), sodium hypochlorite (dose range: 0-7.5 mg/L) and powder activated carbon (dose range: 0-30 mg/L). The treatment process was optimized using computational fluid dynamics (CFD) and response surface methodology. Specifically, a Latin square technique was employed to generate 16 combinations of treating agent types and concentrations which were pilot tested on an 8 m(3)/h multifunctional reactor fed by a secondary effluent with COD and total coliform concentrations ranging from ≈20 to 120 mg/L and from 10(5) to 10(6) CFU/100 mL, respectively. Results were promising, indicating that removal yields up to 71% in COD and 5.4 log in total coliforms were obtained using an optimal combination of aluminum polychloride (dose range ≈ 84-106 µL/L), powder activated carbon ≈ 5 mg/L, natural zeolite (dose range ≈ 34-70 mg/L) and sodium hypochlorite (dose range ≈ 3.4-5.6 mg/L), with all treating agents playing a statistically significant role in determining the overall treatment performance. Remarkably, the combined process was also able to remove ≈ 50% of total phenols, a micropollutant known to be recalcitrant to conventional wastewater treatments.

Solid state dehalogenation of PCBs in contaminated soil using NaBH4.

In this work we present the results of an experimental study on the abatement of polychlorinated biphenyl (PCBs) in contaminated soil using a high energy milling technique, that promotes a reaction only by impact between milling bodies. A sample of soil from a controlled landfill was treated with powdered NaBH(4) using two different hydride/soil ratios (5 and 2.5% w/w). The efficiency of the dehalogenation/hydrogenation reaction was studied as a function of the milling time (3.5 up to 30 h). After each run, the total PCBs content and the production of inorganic chloride were measured. The complete abatement was obtained with a starting PCBs concentration of about 2600 mg/kg. The residual PCBs concentration resulted to be <0.2 mg/kg. The final products of the treatment were biphenyl and NaCl. Other toxic or hazardous organic by-products were not generated. Boron was found as boric acid.

An experimental investigation of the role of appraisal processes in adolescents and their mothers experiencing family conflict.

A social information processing perspective was used to investigate appraisal processes in family conflict situations. Fifty-five young adolescents (32 males and 23 females) and their mothers who were experiencing sufficient conflict to seek mediation assistance, were presented with hypothetical scenarios depicting common sources of conflict. Participants were randomly assigned to two time conditions. After reading each scenario, participants chose one of four interpretations (two hostile and two non-hostile). Time condition did not influence the number of hostile interpretations for mothers, but when instructed to respond quickly, adolescents were more likely to interpret their mother's behaviour as hostile. The findings highlight the need for investigation of specific stressors which influence appraisal processes in family conflict.

Utilization of O-phthalaldehyde-sulphuric acid as a spray reagent in thin-layer chromatographic detection of some indolealkylamines and application to cutaneous secretion extracts of toad species.

An expansion of the utilisation of o-phthalaldehyde in sulphuric acid medium as spray reagent was carried out when tryptophan and some tryptophan-derived indole alkylamines such as tryptamine, serotonin, bufotenine, dehydrobufotenine and bufotenidine were examined by thin-layer chromatography. Rf-values and limits of detection ranging from 20 (serotonin) to 100 (dehydrobufotenine) ng per spot were found. Application of this reagent for the detection of some of these compounds was carried out, using either methanolic extracts or column chromatographic fractions of the skin secretion of the toads Bufo ictericus and Odontophrynus cultripes.