Slow filtration operating conditions for the removal of opportunistic pathogens in a secondary effluent.

The secondary effluent of urban sewage treatment plants contains many opportunistic pathogens (OPs), which pose a potential threat to human health. In this study, the slow filtration technique is employed as the advanced treatment procedure, with the secondary effluent as the treatment object. The effectiveness of the operating conditions of the slow filtration process (filtration rate and Ca concentration) in removing OPs (Pseudomonas aeruginosa, Legionella and Mycobacterium avium) and Escherichia coli from water, as well as the dynamic deposition process of pollutants on the surface of the slow filtration biofilm, was investigated.

Removal of antibiotic resistance genes in secondary effluent by slow filtration-NF process.

In this study, the combined process of slow filtration and low pressure nanofiltration (NF) has been used to deeply remove the antibiotic resistance genes (ARGs) in a secondary effluent, and the mechanism of ARGs removal has been subsequently explored. It is observed that the optimal filtration rate for the slow filtration without biofilm, slow filtration with the aerobic heterotrophic biofilm, slow filtration with the nitrification biofilm and slow filtration with the denitrification biofilm to remove tet A, tet W, sul I, sul II and DOC is 20 cm/h, and the slow filtration with the aerobic heterotrophic biofilm exhibits the highest removal amount. The slow filtration with biofilms removes a high extent of free ARGs.

Removal of antibiotic resistance genes from secondary effluent by processes combining nano-iron, ultrasound-activated persulfate, and ultrafiltration.

Antibiotic resistance genes (ARGs), as a new type of environmental pollutant that threaten human health, have been detected in the effluent of sewage treatment systems. In this study, the removal from water of ARGs, 16S rRNA, class 1 integron (intI1), and dissolved organic carbon (DOC) were investigated using processes combining nano-iron (nFe), ultrasound (US), activated persulfate (PS) and ultrafiltration (UF). The oxidation mechanism was also studied.

Research on Operation Efficiency and Membrane Fouling of A/O-MBR in Reclaimed Water Treatment.

Taking the public building domestic wastewater as an example, the combination of the MBR (membrane bioreactor) process and the traditional A/O (anaerobic-anoxic-oxic) process was established and analyzed in terms of the removal effect of the pollutants, the impact of the microbial community changes on the process, the MBR membrane fouling, the cleaning methods, and the cleaning performance. The results indicated that the effluent water quality of the domestic wastewater treated with the A/O-MBR process was stable and met the emission requirement to the natural water body. There was good microbial diversity in raw water, the anaerobic tank, the anoxic tank, the aerobic MBR tank and the disinfection tank, and the aerobic MBR tank has a wide variety of aerobic microorganisms, which elevates the removal of organics and the nitrification of ammonia nitrogen and ensures the qualification of nitrogen and phosphorus indexes of the system effluent water.

Effects of the Structure of TiO Nanotube Arrays on Its Catalytic Activity for Microbial Fuel Cell.

To enhance the microbial fuel cell (MFC) for wastewater treatment and chemical oxygen demand degradation, TiO nanotubes arrays (TNA) are successfully synthesized on Ti foil substrate by the anodization process in HF and NHF solution, respectively (hereafter, denoted as TNA-HF and TNA-NF). The differences between the two kinds of TNA are revealed based on their morphologies and spectroscopic characterizations. It should be highlighted that 3D TNA-NF with an appropriate dimension can make a positive contribution to the high photocatalytic activity.

Highly Ordered Hierarchical Pt and PtNi Nanowire Arrays for Enhanced Electrocatalytic Activity toward Methanol Oxidation.

Highly ordered hierarchical Pt and PtNi nanowire arrays were prepared using CdS hierarchical nanowire arrays (HNWAs) as sacrificial templates and demonstrated high electrochemical active surface areas. For the resulting Pt HNWAs sample, the peak current for methanol oxidation at +0.74 V was almost 1 order of magnitude higher than that of Pt solid nanowire arrays prepared in a similar manner but without the use of CdS template, and the addition of a Ni cocatalyst effectively enhanced the tolerance against CO poisoning.

The membrane fouling mechanisms of the PAC/BPAC-UF combined process used to treat the secondary effluent from municipal wastewater treatment plant.

The combined processes of powdered activated carbon/biological powdered activated carbon- ultrafiltration (PAC/BPAC-UF) were used to treat secondary effluent. In this study, the effect of PAC and BPAC on membrane flux, membrane resistance and the removal of different molecular weight organic compounds were investigated. In addition, the structure characteristics of the microorganisms of the BPAC were analyzed.

The removal of typical pollutants in secondary effluent by the combined process of powdered activated carbon-ultrafiltration.

This paper focused on the effects of powdered activated carbon (PAC) dosage on ultrafiltration (UF) membrane flux caused by natural organic matter (NOM). Three model foulants, humic acid (HA), bovine serum albumin (BSA) and sodium alginate (SA), were adopted to represent different NOM fractions in secondary effluent treated by the combined process of PAC-UF. Moreover, the membrane fouling resistance and fouling mechanism were also analyzed.

Using reclaimed water as make-up water for a district heating system: a case study in Beijing.

Make-up water used for a district heating system in Beijing is about 63 kg/m(2).a, so the total quantity of make-up water is over 10 million m(3) per year. Water deficiency is very serious in Beijing.