Synergistic effects of combining ozonation, ceramic membrane filtration and biologically active carbon filtration for wastewater reclamation.

In this study, we proposed to apply an integrated process which is comprised of in situ ozonation, ceramic membrane filtration (CMF) and biologically active carbon (BAC) filtration to wastewater reclamation for indirect potable reuse purpose. A pilot-scale (20 m/d) experiment had been run for ten months to validate the prospect of the process in terms of treatment performance and operational stability. Results showed that the in situ O + CMF + BAC process performed well in pollutant removal, with chemical oxygen demand, ammonia, nitrate nitrogen, total phosphorus and turbidity levels in the treated water being 5.

Acidogenic phosphorus recovery from the wastewater sludge of the membrane bioreactor systems with different iron-dosing modes.

A novel acidogenic phosphorus recovery (APR) process was developed in combination with Fe(III)-based chemical phosphorus removal and a membrane bioreactor (MBR) for enhanced wastewater treatment and effective P recovery. Two different system configurations were evaluated: Fe-dosing MBR (Fe-MBR), with the Fe-dosing into the MBR, and Fe-enhanced primary sedimentation followed by the MBR (FeP-MBR). The results show that both systems performed well for enhanced nutrient (N and P) removals and P recovery, with approximately 50% of the total P recovered from the municipal wastewater in the form of vivianite.

Topochemical synthesis and photocatalytic activity of 3D hierarchical BaTiO microspheres constructed from crystal-axis-oriented nanosheets.

Novel BaTiO hierarchical porous microspheres were achieved by using HTiO·HO (HTO) hierarchical microspheres as a precursor template via a facile solvothermal method. Interestingly, the BaTiO microspheres were constructed with two-dimensional (2D) nanosheets, which were composed of many order nanocrystals with crystal-axis-orientation. The special hierarchical structure, which is both macroporous and mesoporous, exhibits a large specific surface area and a high total pore volume.

Comprehensive evaluation of pharmaceuticals and personal care products (PPCPs) in typical highly urbanized regions across China.

This study evaluated the occurrence of 36 PPCPs in urban river water samples collected from Beijing, Changzhou and Shenzhen. Twenty-eight compounds were detected. Compounds found with highest median concentrations included: sulfadimethoxine (164 ng/L), sulpiride (77.

[Direct removal of typical endocrine disruptors from heavily polluted river water by ozonation].

Ozone was applied to study the removal of conventional pollutants and typical endocrine disrupters (EDs), including bisphenol A (BPA), 4-n-nonylphenol(NP), 4-tert-octylphenol (OP), estrone (E1), estradiol (E2), 17alpha-estradiol (17alpha-E2), estriol (E3) and ethinylestradiol (EE2) , from heavily polluted river water. The O3 dose was designed at 28 mg x L(-1) for 30 min and 42 mg x L(-1) for 80 min. Pollutants in terms of chemical oxygen demand (COD) and ammonia nitrogen can not be removed efficiently, ranged from 3% to 7%.

Assimilation of 17α-ethinylestradiol by sludge and its stress on microbial communities under aerobic and anaerobic conditions.

The efficiency of 2 common types sludge, activated sludge and digesting sludge, to biodegrade ethinylestradiol (EE2) under aerobic and anaerobic conditions, and the impacts of EE2 on microbial community structure were investigated. The results showed that 75%-88% EE2 were removed under aerobic conditions and the values were 75%-84% under anaerobic conditions. The diversity of microbial species in the tested sludge decreased when exposed to EE2 and the shift of microbial community structures was dependent on both sludge types and process conditions.

Thermodynamics and photochemical properties of alpha, beta, and gamma-hexabromocyclododecanes: a theoretical study.

The thermodynamics and photochemical properties of -alpha, +beta, and -gamma-hexabromocyclododecanes (HBCDs) have been investigated by density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations. The optimized geometries of HBCDs are in agreement with recently published X-ray crystallographic data. The thermodynamic properties of three HBCDs indicate that alpha-HBCD is the most stable one.

[Dynamic experiment on controlling of Microcystis aeruginosa by UV-C irradiation].

A plug-flow UV-C reactor equipped with low pressure UV lamp was utilized to study the suppression effect after UV-C irradiation under the dynamic conditions on Microcystis aeruginosa, a typical cyanobacterium in algae blooms in China. The culture fluid of Microcystis aeruginosa was exposed to UV-C irradiation when pumped through the reactor. After that, the fluid was incubated under the normal culture condition, and sampled at 2 h, 1 d, 3 d, 5 d, 7 d, 9 d for determination of cell density using the inverted system fluorescence microscope.

[Water quality safety of ozonation and biologically activated carbon process in application].

Ozonation and biologically activated carbon process, one of advanced treatment technologies, has been applied in many places at home and abroad. However, some emerging water quality problems appeared in operation. Drinking water treatment plant (6 x 10(5) m3/d) with ozonation and biologically activated carbon process (O3-BAC process) was investigated systematically, including microbial safety, the excessive growth of aquatic microorganism and chemical stability of water quality.

[Effects of fractal structure on settling velocities of flocs].

Fractal structures of kaolin and humic flcos by the mass-size method based on the microbalance and free-settling method based on particle image velocimetry technique were investigated. The results showed that kaolin and humic flocs were characterized by fractal structure. The three-dimensional fractal dimensions of Fe flocs with more compact structure ranged from 2.

[Numerical simulation of TP transport after overflow of rainwater into urban lake].

Based on the three-dimensional advection-diffusion-reflection equation, a two-dimensional TP transport equation was deduced to simulate TP distribution and transport after overflow rainwater into urban lake from storm sewer system during rainstorm. The model has a good agreement with a group of monitor data at Lake Lichee in Shenzhen, China. The model was applied to compute the scenario in Lake Lichee under the design rainstorm, and analyse the fate of TP.

[Treatment effect of eutrophication restoration project for Lichee Lake in Shenzhen].

Based on 9-month monitoring field data, this paper analyzes the variation of chlorophyll-a (Chl-a), total phosphorus (TP), total nitrogen (TN) and transparency (SD) in different sub-lake districts in order to study the treatment effect of eutrophication restoration project in Lichee Lake in Shenzhen. The statistical results show that, the average of TP and TN for whole lake were below 0.1 mg x L(-1) and 1.

[Pollutant loading analyses and TP model calculation for eutrophication in Lichee Lake in Shenzhen].

Based on 9-month consecutive in situ monitoring data, this paper investigated the pollutant sources and loadings of eutrophication in Lichee Lake in Shenzhen. The external source mainly comes from overflow of storm sewer system, which will deteriorate water quality in lake. Total phosphorus concentration was measured with a maximum of 0.

[Three-dimensional fluorescence fingerprint for source determination of dissolved organic matters in polluted river].

Fluorescence fingerprint technique was used to characterize dissolved organic matter (DOM) in river from different sources. The results showed that two types of DOM fluorescence signals were observed in river water: a humic-like fluorescence with three maxima at lambda(ex)/lambda(em) = 250/460 nm(A1), 220/400 nm(A2) and 325/420 nm(C); and a protein-like fluorescence with two maxima at lambda(ex)/lambda(em) = 230/360 nm(T2) and 285/357 nm(T1). The intensity of both of protein-like fluorescence distinctly increased because of the domestic wastewater drainage in the tributary stream.

[Study on the effects of organic removal by traditional purification process with three-dimensional excitation emission matrix fluorescence spectroscopy].

Fluorescence spectroscopy is widely used to elucidate the origin and structure of organic matters in water substance. Due to its high sensitivity, good selectivity and nondestructive nature, fluorescence technique is suitable to the study of chemical and physical properties of organic matters. Three-dimensional excitation emission matrix fluorescence spectroscopy (3DEEM) was applied to analyze the effects of organic removal by traditional purification process.

[Characteristics of anaerobic sequencing batch reactor for the treatment of high-solids-content waste].

Based on the experiments of digestion of thermo-hydrolyzed sewage sludge in both mesophilic and thermophilic anaerobic sequencing batch reactors (ASBRs) with 20, 10, 7.5, 5d hydraulic retention time (HRT), operating characteristics of ASBR for treatment of high-solids-content waste were investigated. ASBR can efficiently accumulates suspended solids and keep high concentration solids, however there exists a "critical point" of ASBR, which means the maximum capability to accumulate suspended solids without negative effects on ASBR stability, and beyond which the performance deteriorates.

[Study of sonochemical degradation of microcystins].

Sonochemical degradation of microcystins (MC) produced by microcystis in water and the influence of various ultrasonic parameters were studied. The results show that microcystins could be effectively degraded in ultrasonic fields. 150 kHz is the best ultrasound frequency for microcystins degradation, and the removal ratio of microcystins reached 70% after 20 min ultrasonic irradiation at 150 kHz and 40 W.

Modification on the conventional procedure to measure AOC in drinking water.

Additional phosphorus will be introduced to water sample if the conventional procedure is used to measure assimilable organic carbon (AOC) in drinking water. It has been shown that there are the cases that phosphorus is the limiting nutrient for microbial growth in drinking water. The measured value of AOC would not be able to indicate appropriately the regrowth potential of bacteria in this case.

[Streaming current of waterworks sludge].

The applicability of streaming current in waterworks sludge treatment as indicator of coagulant dosage and pH control was investigated in this study. Experiments were conducted on sludge settling behaviors and dewatering processes. At the aspect of sludge settleability research showed the theoretical optimal dosage, pH was 8.

[Comparison on the performance of biostyr and bio-ceramic filter used for biological pretreatment of raw water].

A new biological filter called biostyr using biostyrene as media to purify raw water was compared with the widely studied bio-ceramic filter. The raw water was taken from a reservoir located in Northern China. It was shown this new biological filter could obviously improve the raw water quality.

[Movement and transformation of nitrate in soil by non-uniform electrokinetics].

Movement and accumulation of nitrate in soil and groundwater has become a serious threat in many cities and agricultural areas. At the same time, application of nitrate as bacterial nitrogenous nutrient in the in-situ bioremediation of some organics-polluted sites is often required. Laboratory experiments were conducted to examine the feasibility of using non-uniform electrokinetics (NUEK) to control the movement of nitrate in unsaturated soil-water system.

Phosphorus limitation on bacterial regrowth in drinking water.

Assimilable organic carbon (AOC) test and bacterial regrowth potential (BRP) analysis were used to investigate the effect of phosphorus on bacterial regrowth in the drinking water that was made from some raw water taken from a reservoir located in northern China. It was shown that AOC of the drinking water samples increased by 43.9%-59.