[Long-term Impacts of TiO Nanoparticles on the Stability of an Anaerobic Granular Sludge Bioreactor].

In the present study, the fate and long-term effect of TiO nanoparticles (NPs) on anaerobic granular sludge (AGS) was evaluated in an anaerobic methanogenic system. In the short-term experiment, the methane production rate decreased when the dosage of TiO NPs was greater than 150 mg·g. However, no significant difference in the products of acidification and methanation between the control and 150 mg·g(as VSS) of TiO NPs assays was observed, indicating low bacteria cytotoxicity of TiO NPs on AGS in dark anaerobic digestion.

[Acute Toxic Effects of Bromate on Aquatic Organisms].

Acute toxic effects of potassium bromate, sodium bromate and potassium bromide on luminescent bacteria, water flea, green alga and zebrafish were studied using standard toxic testing methods. The results showed that the pollutants had no effect on the luminous intensity of luminescent bacteria. The 96 h EC5.

[Effects of Bromate on the Growth and Physiological Characteristics of ].

The effects of bromate on the growth and physiological characteristics of were investigated via the static exposure experiments and tested by flow cytometry. The results showed that when was continuously exposed to bromate for 96 h at 8 mmol·L, the specific growth rates and cell membrane integrity decreased significantly, while the esterase activity, mitochondrial membrane potential and reactive oxygen species (ROS) increased significantly. The membrane-damaged cells could be found from the scanning electron microscopy analysis.

Study on the factors affecting simultaneous removal of ammonia and manganese by pilot-scale biological aerated filter (BAF) for drinking water pre-treatment.

It was demonstrated that simultaneous removal of ammonia and manganese could be accomplished by biological aerated filter (BAF) with low-cost lava as media. Long-term operation performance and impact factors were systematically studied. DGGE analysis demonstrated that ammonia oxidizing bacteria (AOB), manganese oxidizing bacteria (MOB) and simultaneous ammonia and manganese oxidizing bacteria (SAMOB) co-existed in the bio-film.

[Removing efficiency study on Cyclops cooperating with water treatment process by alternative oxidants].

The synergic removal effect on Cyclops was studied with 4 kinds of dosages of pre-oxidants such as chloramines, chlorine, O3 and potassium permanganate composite followed by different sets of clarification treatment process pilot systems. The removal mechanisms of Cyclops in different treatment units were analyzed. The experiments results show that the inactivation rate of chlorine (25%) is the highest compared with the chloramines (21%), potassium permanganate composite (8%) and O3 (9%) in the pre-oxidation stage, while the removal rate is changed after the filtration and the sequence is chloramines (90%) > chlorine (88%) > O3 (83%) > potassium permanganate composite (80%).

[Effectiveness and characteristics of treating algae-laden raw water by stocking silver carp].

To reduce the negative effect of algae on conventional water treatment, a full-scale research of removing algae from algae-laden raw water by stocking filter-feeding silver carp was processed. After the pretreatment in a presedimentation tank with silver carp, the concentration of phytoplankton, the biomass of cyanobacteria and Microsystis flos-aquae in algae-laden raw water with Microsystis flos-aquae its dominant species decreased 61.8%, 76.

[Toxicity and influencing factors of chlorine dioxide to chironomid larvae].

The toxic effect of chlorine dioxide to the different instar larvae of chironomid was studied using raw water as test sample. Furthermore, the effect of temperature and contact time on toxicity of chlorine dioxide was observed. It was found that chlorine dioxide possessed significantly toxic effect, and the LC50 value of chlorine dioxide to the 4th instar larvae was 0.

[Preparation of a composite coagulant from fly ash and its application in domestic wastewater treatment].

Fly ash was investigated as a raw material for the preparation of a composite coagulant with sulfuric acid. Types of acid solution, H2SO4 concentration, ratio of H2SO4 to fly ash and stirring time were respectively examined as factors that influenced the efficiency of converting the iron and aluminum components into a composite coagulant and coagulation performance on domestic wastewater. The coagulant was attained at the condition of H2SO4-fly ash ratio of 5 mL/g, H2SO4 of 2 mol/L, stirring time of 4h and stabling time of 30 min, and contained Fe3+ of 0.

Reuse of carwash wastewater with hollow fiber membrane aided by enhanced coagulation and activated carbon treatments.

The particles from carwash wastewater were separated by a hollow fiber membrane aided by a enhanced coagulation and activated carbon. This study demonstrated that the addition of KMnO(4) to coagulant (PAC) could enhance the efficiency of coagulation, which helped reduce clogging of the ultrafiltration membrane and activated carbon. The existence of LAS can loosen the gel layer on the membrane and improve the flux.

[Inactivation and removal of chlorine dioxide on cyclops of zooplankton].

Comparative experiments on the inactivation of cyclops by chlorine dioxide and chlorine were conducted. Batch experiments were performed in order to analyze the influence of pH value, organic precursor concentration on the rate of inactivation of cyclops with chlorine dioxide. In addition, the synergistic effect of different pre-oxidation followed by coagulation process on removal of cyclops in raw water was evaluated.

Biological control experiment of excess propagation of Cyclops for drinking water security.

Cyclops of zooplankton propagated excessively in eutrophic water body and could not be effectively inactivated by the conventional disinfections process like chlorination due to its stronger resistance to oxidation. In this study, an ecological project was put forward for the excess propagation control of Cyclops by stocking the filter-feeding fishes such as silver carp and bighead carp under the condition of no extraneous nutrient feeding. The results of experiments with different stocking biomass showed that the propagation of Cyclops could be controlled effectively, and the water quality was improved simultaneously by impacting on nutriment level and plankton community structure at proper stocking density of 30 g/m3 of water.

[Study on the technology of treating low temperature and low turbidity water by membrane bioreactor].

For the purpose of solving the problem of low temperature and low turbidity water treatment, a pilot study was made on the treatment of Songhuajiang River raw water with low temperature and low turbidity by using membrane bioreactor (MBR) process, and the removal effects of organic pollutants and turbidity and membrane filtration period were also investigated. The results showed that the effluent turbidity was lower than 1 NTU and its removal efficiency was over 90%. The removal efficiency of permanganate index and UV254 were about 40% - 50% and 30% - 45%, respectively.

Removal effect on Mesocyclops leukarti and mutagenicity with chlorine dioxide.

Mesocyclops leukurti of zooplankton propagates excessively in eutrophic water body and it cannot be effectively inactivated by the conventional drinking water treatment process. In order to tackle this problem, a study of removal effect on Mesocyclops leukarti with chlorine dioxide in a waterworks was performed. The results showed that Mesocyclops leukarti could be effectively removed from water by 1.

Inactivation of Chironomid larvae with chlorine dioxide.

In this paper, comparative experiments on the inactivation of Chironomid larvae by chlorine dioxide and chlorine were conducted. In addition, batch experiments were performed in order to analyze the influence of pH value, organic precursor concentration and temperature on the inactivation efficiency of Chironomid larvae with chlorine dioxide. Based on it, removal effect of different pre-oxidation followed by coagulation process on Chironomid larvae in raw water was evaluated.

Study of removal effect on Mesocyclops leukarti with oxidants.

Cyclops of zooplankton propagates prolifically in eutrophic waterbody and it cannot be exterminated by conventional disinfection process. The mutagenicity of Mesocyclops leukarti and its extermination with oxidants in a drinking waterworks in China were studied. Among five oxidants for use in bench-scale, chlorine dioxide is the most effective and the potassium permanganate is the weakest against Mesocyclops leukarti under the same conditions.

[Toxicity and influencing factors of liquid chlorine on chironomid larvae].

The excessive propagation of Chironomid larvae (red worm) in the sedimentation tanks is a difficult problem for the normal function of waterworks. The toxic effect of liquid chlorine on the different instar larvae of Chironomid was studied using distilled water as test sample. Furthermore, the effect of pH value, organic matter content, ammonia nitrogen, and algae content on toxicity of liquid chlorine was observed.

[O3/H2O2 oxidation processes of cyclops of zooplankton inactivation in water].

The inactivation effects of ozone, hydrogen peroxide, O3/H2O2 processes on Cyclops of zooplankton were discussed. It was found that O3/H2O2 possessed more favorable inactivation effect on Cyclops compared with the others, in distilled water with 1.0 mg/L of O3 and 4 mg/L of H2O2 the inactivation effect was 100% after 30 min contacting; ozone also had favorable inactivation effect, the inactivation effect is 80% by 1.

Removal of disinfection by-products formation potential by biologically intensified process.

The removal of disinfection by-products formation potential (DBPFP) in artificially intensified biological activated carbon (IBAC) process which is developed on the basis of traditional ozone granular activated carbon was evaluated. By IBAC removals of 31% and 68% for THMFP and HAAFP were obtained respectively. Under identical conditions, the removals of the same substances were 4% and 32% respectively only by the granular activated carbon (GAC) process.

Full-scale study of removal effect on Cyclops of zooplankton with chlorine dioxide.

Cyclops of zooplankton propagated excessively in eutrophic water body and could not be effectively inactivated by the conventional disinfections process like chlorination due to its stronger resistance to oxidation. In this paper, a full-scale study of chlorine dioxide preoxidation cooperating with routine clarification process for Cyclops removal was conducted in a waterworks. The experimental results were compared with that of the existing prechlorination process in several aspects: including the Cyclops removal efficiencies of water samples taken from the outlets of sedimentation tank and sand filter and the security of drinking water and so on.

Study on coagulation property of metal-polysilicate coagulants in low turbidity water treatment.

In order to remove the low turbidity present in surface water, a novel metal-polysilicate coagulant was used to treat the raw water taken from Tanjiang River in Guangdong Province. This study on the effects of Al/Fe molar ratio on the performance of a complex compound formed by polysilicic acid, aluminium and ferric salt (PAFS) showed that PAFS with Al/Fe ratio of 10:3 seemed to have the best coagulation performance in removing turbidity and color. Experimental results showed that under the conditions of polymerization time of 15 d, sedimentation time of 12 min, and pH of 6-8, PAFS with Al/Fe molar ratio of 10:3 had the best coagulation efficiency and lowest residual Al concentration.