[Identification and PAC Adsorption of Foulants Responsible for Irreversible Fouling During Ultrafiltration of Dongjiang River Water].

Foulants responsible for hydraulic irreversible fouling in Dongjiang River water were identified by ultrafiltration process and their removal by powdered activated carbon (PAC) adsorption treatment was investigated using fluorescent excitation emission matrix and parallel factor analysis (EEM-PARAFAC). A correlation analysis was then carried out for samples between the maximum fluorescence intensities () of three PARAFAC components after PAC adsorption and the surface properties of corresponding PAC samples. The results showed that two humic-like (C1 and C3) and one tryptophan-like fluorescent components were obtained through PARAFAC analysis, in which tryptophan-like component C2 was found to be the main substance in hydraulic irreversible foulants extracted from fouled membrane.

[Effects of Pretreatment on Hydraulic Irreversible Membrane Fouling During Ultrafiltration Short Process: A Pilot Study].

Pilot-scale performances for ultrafiltration of Dongjiang river water without and with micro-coagulation and coagulation-adsorption-sedimentation pretreatments were conducted to investigate the effects of pretreatments on hydraulic irreversible fouling of ultrafiltration short processes. Scanning electron microscope (SEM) imaging, high performance size exclusion chromatography (HPSEC) and fluorescence excitation-emission matrix (EEM) were employed to identify foulants responsible for irreversible fouling during ultrafiltration with and without pretreatments. The results showed that the hydraulic irreversible fouling rate was 0.

Fouling of ultrafiltration membrane by algal-rich water: effect of kalium, calcium, and aluminum.

Algae are commonly aquatic plants showing generally negatively charged. The fouling behavior of hollow-fiber ultrafiltration membrane by algal-rich water could be therefore influenced by various cations (K(+), Ca(2+), and Al(3+)) and their doses. Microcystis aeruginosa solution was used as the feed solution to study the fouling in detail.

Measuring the activity of heterotrophic microorganism in membrane bioreactor for drinking water treatment.

In order to quantify the activity of heterotrophic microorganism in membrane bioreactor (MBR) for drinking water treatment, biomass respiration potential (BRP) test and 2,3,5-triphenyl tetrazolium chloride-dehydrogenase activity (TTC-DHA) test were introduced and modified. A sludge concentration ratio of 5:1, incubation time of 2h, an incubation temperature that was close to the real operational temperature, and using a mixture of main AOC components as the substrate were adopted as the optimum parameters for determination of DHA in drinking water MBR. A remarkable consistency among BDOC removal, BRP and DHA for assessing biological performance in different MBRs was achieved.

Effect of enhanced coagulation by KMnO(4) on the fouling of ultrafiltration membranes.

Pre-coagulation enhanced by KMnO(4) before ultrafiltration (KCUF) was compared with normal pre-coagulation by alum (CUF) in the ultrafiltration of water from the Songhua River, China. The trans-membrane pressure (TMP) with KCUF was much lower than that when alum alone was used. With KCUF a slower increment of TMP occurred, even under conditions of high river water turbidity.

Characteristics of adsorbents made from biological, chemical and hybrid sludges and their effect on organics removal in wastewater treatment.

Meso-macropore adsorbents were prepared from biological sludge, chemical sludge and hybrid sludge of biological and chemical sludges, by chemically activating with 18.0 M H(2)SO(4) in the mass ratio of 1:3, and then pyrolyzing at 550 °C for 1 h in anoxic atmosphere. The physical and chemical characteristics of the sludge-based adsorbents were examined in terms of surface physical morphology, specific surface area and pore size distribution, aluminum and iron contents, surface functional groups and crystal structure.

Consecutive chemical cleaning of fouled PVC membrane using NaOH and ethanol during ultrafiltration of river water.

Chemical cleaning of fouled hollow-fiber polyvinyl chloride (PVC) membrane with the consecutive use of NaOH and ethanol during ultrafiltration of river water was investigated in the study. Results showed that through the chemical cleaning with 1% NaOH for 30min, a negative cleaning efficiency of -14.6% was observed for the PVC membrane.

Hybrid process of BAC and sMBR for treating polluted raw water.

The hybrid process of biological activated carbon (BAC) and submerged membrane bioreactor (sMBR) was evaluated for the drinking water treatment from polluted raw water, with the respective hydraulic retention time of 0.5 h. The results confirmed the synergetic effects between the BAC and the subsequent sMBR.

[Oxidization characteristic of chlorine on the biofilm in simulated drinking water distribution system].

In the article, the inactivation effect of chlorine on E. coli biofilm and the influence of chlorine oxidization on the contents of assimilable organic carbon (AOC), microbially available phosphorus (MAP) and bacterial regrowth potential (BRP) was investigated in the simulated drinking water distribution system. Results showed that chlorine resulted in more efficient reduction on suspended E.

[Mechanism of natural organic matter removal by potassium permanganate composite enhanced coagulation].

Streaming current technique, fluctuation of transmitted light technique, molecular weight distribution and XAD resin adsorption technique were used to study the mechanism of natural organic matter removal by potassium permanganate composite (PPC) enhanced coagulation. Results showed that natural organic matter removal efficiency increased 13% by 0.75 mg/L potassium permanganate composite enhanced coagulation compared with that of alum coagulation alone.

[Effect of chloramines disinfection for biofilm formation control on copper and stainless steel pipe materials].

Two rotating annular bioreactors (RABs) with copper and stainless steel pipe materials were adopted in the study, the effects of these two pipe materials and chloramines disinfection on biofilms formation in drinking water distribution system were evaluated. The maximum viable bacterial number in biofilm of copper and stainless steel reached 5.5 x 10(3) CFU/cm2 and 2.

Membrane coagulation bioreactor (MCBR) for drinking water treatment.

In this paper, a novel submerged ultrafiltration (UF) membrane coagulation bioreactor (MCBR) process was evaluated for drinking water treatment at a hydraulic retention time (HRT) as short as 0.5h. The MCBR performed well not only in the elimination of particulates and microorganisms, but also in almost complete nitrification and phosphate removal.

[Mechanism and promotion effect of K+ on yield of Fe(VI)].

The mechanism and promotion effects of K+ on the yield of Fe(VI) were studied during the reaction of forming ferrate. The experiment results showed that K+ is far better than Na+ for the preparation of Fe(VI) at temperatures higher than 50 degrees C. The optimal temperature for the preparation of Fe(VI) with K+ is 65 degrees C.

[Characteristic of natural organic matter removal by ferric and aluminium coagulation].

Natural organic matter removal efficiency and characteristic by ferric chloride and aluminium sulphate were studied. Results showed that ferric chloride was effective in natural organic matter removal when coagulant dosage was higher than 15 mg/L, while aluminium was effective at lower dosage. The TOC of water was reduced to 4.

[Study on adsorption of bisphenol A from aqueous solution on modified activated Carbons].

A commercial activated carbon (WV A1100) was modified with nitric acid, sodium hydroxide and thermal treatment in an atmosphere of N2. Several techniques were used to characterize the physicochemical properties of these materials including BET, XPS, pH(PZC) and Boehm titration. The results indicated that the specific surface area of the W20 remarkably decreased after oxidized by nitric acid.

Salicylate-spectrophotometric determination of inorganic monochloramine.

On the basis of classical Berthelot reaction, a simple salicylate-spectrophotometric method was developed for quantitative determination of inorganic monochloramine in water samples. With the catalysis of disodium pentacyanonitrosylferrate(III), inorganic monochloramine reacts with salicylate in equimolar to produce indophenol compound which has an intense absorption at 703nm. Parameters that influence method performance, such as pH, dosage of salicylate and nitroprussiate and reaction time, were modified to enhance the method performance.

[Ozonation of representative endocrine disruptors (EDs) in water].

The effects of ozone dose, bicarbonate concentration and pH on endocrine disruptors(EDs) removal, such as E1, E2, EE2, DES and 4-n-NP, were investigated through batch experiment. The results indicated that the removal rates were enhanced by increasing ozone dose, and O3 exposures of only 63.6 microg/L were calculated to achieve > or = 92.

[Image and coagulation behavior of colloidal hydrated manganese dioxide flocculate particles].

The structure and image of colloidal hydrated manganese dioxide flocculate particles and the electrical charge characteristic of colloidal hydrated manganese dioxide were studied by transmission electron microscope (TEM) and zeta potential (ZP) measurement. The surface chemistry characteristic of colloidal hydrated manganese dioxide was characterized by IR spectra and XRD technology etc. Then the coagulating property and behavior of the colloidal hydrated manganese dioxide produced by KMnO4 were also studied by jar test.

[Effects of potassium permanganate on natural organic matter chlorination activity].

Effects of potassium permanganate (PP) oxidation on natural organic matter(NOM) chlorination activity was studied in the article. Natural organic matter was separated into humic acid (HA), fulvic acid(FA), hydrophilic acid(HPIA) and non-hydrophilic acid (HPI-NA) fraction four fractions by XAD resin adsorption technique. Potassium permanganate oxidation alone increased HA and HPIA chlorination activity and decrease that of FA and HPI-NA.

[Characteristics and chlorination activity of natural organic matter in water].

XAD resin adsorption technique is used to separate natural organic matter in the water into four fractions, namely: humic acid fraction, fulvic acid fraction, hydrophilic acid fraction and hydrophilic non acid fraction. Trihalomethane formation velocity and chlorination activity of each fraction are studied. Results show that fulvic acid is the main components which contained 50.

[Effectiveness and mechanism of permanganate enhancing arsenite co-precipitation with ferric chloride].

The effectiveness and mechanism of permanganate enhancing arsenite (As(III)) co-precipitation with ferric chloride is investigated. Effects of parameters such as pH, natural organic matter (NOM) on As removal are studied. Permanganate significantly enhances As(III) removal for ferric co-precipitation (FCP) process.

Effects of chlorine content and position of chlorinated phenols on their oxidation kinetics by potassium permanganate.

Chlorine content and position of chlorinated phenols have many significant effects on the reactivity of oxido-reduction. The effects of chlorine content and position of chlorinated phenols on their oxidation kinetics by potassium permanganate were evaluated through different kinetics studies. Since chlorine was an electron withdrawing atom, the substitution of chlorine on the aromatic ring decreased the oxidation rate constant by sigma-electron withdrawing conductive effect.