2011 Vol. 1, No. 2

Water Pollution Control Technology and Resource Utilization
UV-assisted Electrochemical Treatment of Landfill Leachate in a Continuous Flow Reactor
XIAO Shu-hu, SONG Yong-hui, WAN Dong-jin, ZHAO Xu, XIAO Hong-kang
2011, 1(2): 95-100. doi: 10.3969/j.issn.1674-991X.2011.02.016
Abstract(5480) PDF(757KB)(1711)
Abstract:
A magnified continuous-flow integrated reactor was developed and UV-assisted electrochemical (UAE) oxidation was adopted to treat leachate from a municipal sanitary landfill after biological process. The effects of hydraulic retention time and applied electric current density on the removal of CODCr and NH3-N were investigated, and UAE process and single electrochemical process compared to observe the synergetic effect. Based on analysis of UV-vis spectra (200~500 nm) and GC/MS, it was found that many small organic molecules such as organic carboxylic acids were generated in the process, which could be responsible for the improvement of biodegradability. The results showed that UAE process could treat landfill leachate effectively. Without pH adjustment and electrolyte addition, 74.3% of CODCr and 94.9% of NH3-N could be degraded in the UAE process at a retention time of 85 min and electric current density of 21.2 mA/cm2. Simultaneously, the BOD5/CODCr of leachate could reach at about 0.6, and its biodegradability increased by about 12 times.
Degradation of Acetophenone in Wastewater by Electro-Fenton Process
DOU Lian-feng, SONG Yu-dong, ZHOU Yue-xi, QIN Hong-ke, LAN Mei, XU Ji-xian
2011, 1(2): 101-105. doi: 10.3969/j.issn.1674-991X.2011.02.017
Abstract(5201) PDF(552KB)(1747)
Abstract:
Electro-Fenton process with activated carbon fiber as the cathode and Ti/SnO2-Sb2O3 as the anode was used in the treatment of acetophenone wastewater. Effects of Fe2+ concentration and electric current density on acetophenone degradation were investigated. It was indicated that the phenyl in acetophenone molecular could be destroyed by electro-Fenton process and chemical oxygen demand (CODCr) of the wastewater decreased significantly. Compared with traditional two-dimensional electrode process in which no Fe2+ was added, the pollutant removal efficiency and current efficiency by electro-Fenton process were both higher. Current density has significant influences on the pollutant removal. Higher current density raised pollutant removal efficiency while lowering current efficiency. Under the conditions of electric current density 10.0 mA/cm2, Fe2+ 0.1 mmol/L and initial pH 4.0, the removal efficiencies of CODCr and acetophenone at 180 min were 58.96% and above 90%, respectively.
High-temperature Enhanced Electrochemical Treatment of Fosfomycin Sodium Pharmaceutical Wastewater
XIAO Hong-kang, XIAO Shu-hu, SONG Yong-hui, ZHANG Guo-fang, ZENG Ping, SHAO Hong, LI Hui
2011, 1(2): 106-110. doi: 10.3969/j.issn.1674-991X.2011.02.018
Abstract(6089) PDF(581KB)(1822)
Abstract:
The effect of electrochemical treatment for fosfomycin sodium pharmaceutical wastewater using RuO2/Ti as anode was investigated. The influences of temperature, NaCl concentration, initial pH and electric current on the degradation of CODCr and organic phosphorus were studied in details. The results showed that under the conditions of reaction temperature 80 ℃, concentration of NaCl 0.2 mol/L, initial pH 3.42 and electric current 4.0 A, the concentration of CODCr and organic phosphorus could degrade from 12 086 and 1 375 mg/L to 4 278 and 502 mg/L, with the removal rates of CODCr and organic phosphorus being over 64.7% and 63.5%, respectively. The biodegradability of wastewater was improved significantly with the BOD5/CODCr ratio increasing from 0.19 to 0.34.
Study on the Treatment of Wastewater Containing High-concentration Ammonia Nitrogen with Aerobic Denitrifying Bacteria
JIU Wei-jing, WANG Ping, YUE Jian-wei
2011, 1(2): 111-117. doi: 10.3969/j.issn.1674-991X.2011.02.019
Abstract(6307) PDF(912KB)(2067)
Abstract:
The treatment of simulated wastewater containing high-concentration (up to 700 mg/L) ammonia nitrogen with heterotrophic nitrification-aerobic strains in Sequencing Batch Reactor (SBR) was studied. Four influencing factors of SBR including the temperature, dissolved oxygen concentration, pH and hydraulic retention time were studied and the optimal operating conditions obtained. The results indicated that the efficiency of simultaneous nitrification and denitrification by seeding sludge and dominant bacteria could be enhanced after cultured for forty-five operational cycles in SBR. Under the optimal conditions of temperature 23~25 ℃, dissolved oxygen concentration 2 mg/L, pH 6.8-8.0 and hydraulic retention time 78 h, when the chemical oxygen demand was 2 500 mg/L and the ammonia nitrogen was 700 mg/L in the influent, the chemical oxygen demand removal efficiency could reach 88%-93%, while the ammonia nitrogen and total nitrogen removal efficiency could achieve as high as 98%~99% and 86%-93% respectively.
Optimization the Parameters of UZBAF for Treatment of Rural Sewage
LIU Jin, NAN Guo-ying, YANG Tian-xue
2011, 1(2): 118-122. doi: 10.3969/j.issn.1674-991X.2011.02.020
Abstract(5515) PDF(605KB)(1788)
Abstract:
The water pollution was increasingly serious recently in China, and the rural sewage pollution accounted for high proportion. The up-flow biological aerated filter (UZBAF) with inner diameter of 185 cm and with 54 L of built-in natural zeolite filter sand was used in the demonstration base for harmless treatment of rural sewage. The results showed that under the conditions of hydraulic loading 2 m3/h and residence time 1.0 h, when the gas-water ratio increased from 2∶1 to 4∶1, CODCr average removal rate increased from 75.2% to 83.4%, BOD5 removal rate increased by 5.9%; turbidity removal rate increased from 91.9% to 94.8%, NH4+-N average removal rate increased from 82.6% to 98.1%, NH4+-N average concentration of the effluent fell from 3.3 mg/L to 0.28 mg/L; the removal rate of TN, TP, alkalinity and conductivity was 56.2%, 26.7%, 27.5% and 10.8%, respectively; and the removal rate of bacteria and ascaris eggs was 99.9% and 100%, respectively. The effluent could reach the target of the first-grade discharge standard of Synthetical Draining Standard of Sewage (GB 8978-1996). It was concluded that under the conditions of hydraulic loading 2 m3/h and residence time 1.0 h, UZBAF devices could realize harmless treatment of rural sewage.
Control and Management of Water Toxicity
Bacterial Diversity of the Combined Ozonation-ASBR/SBR Sludge Reduction with Simultaneous Nitrogen and Phosphorus
ZHAO Lin-lin, WANG Hai-yan, YANG Hui-fen, HE Zan, ZHOU Yue-xi, ZHANG Le, PANG Zhao-hui
2011, 1(2): 123-130. doi: 10.3969/j.issn.1674–991X.2011.02.021
Abstract(5924) PDF(1018KB)(1851)
Abstract:
The bacterial diversity in the ASBR and SBR of the combined process, i.e. combined ozonation-ASBR/SBR sludge reduction with simultaneous nitrogen and phosphorus removal process was studied by molecular biological PCR-DGGE method before and after sludge reduction. The results indicated that the dominant bacterial communities in the ASBR were Firmicutes bacterium, β-proteobacterium, γ-proteobacterium and Bacteroidetes bacterium. The bacterial richness in SBR after sludge reduction was slightly increased compared with that before sludge reduction, but with high similarity (85%). The dominant bacteria diversity of SBR was not influenced significantly by the ozone dosage for sludge reduction. There were Firmicutes bacterium, Candidate division TM7, ammonia-oxidizing bacterium, Bacteroidetes bacterium, β-proteobacterium, Denitrifying bacterium, Pseudomonas sp and Nitrosococcus halophilus Nc4 in SBR both before and after sludge reduction. However, the number of Bacteroidetes bacterium, β-proteobacterium, Denitrifying bacterium and Nitrosococcus halophilus Nc4 in SBR after sludge reduction was slightly higher than that before sludge reduction.
Study on Isolation and Identification of a Strain Heterotrophic chlorella and its Growth Characteristics
LI Ao-bo, WANG Ping, ZHANG Zheng-jie, JIU Wei-jing, LI Jin-sui
2011, 1(2): 131-136. doi: 10.3969/j.issn.1674-991X.2011.02.022
Abstract(4936) PDF(759KB)(1993)
Abstract:
A heterotrophic WLZ-H strain growing fast was screened from natural waters. The cell morphology of the alga strain was analyzed with scanning electron microscope and, in combination with 16S rDNA molecular biology identification method, it was preliminarily conclude that the WLZ-H strain belonged to Chlorella sorokiniana.Single environmental factor test on the WLZ-H strain showed that the concentration of KNO3 and glucose had significant effects on WLZ-H strain growth; too high temperature would decrease enzyme activity of WLZ-H strain and consequently decrease its growth; pH would change with the growth of WLZ-H strain and reach the suitable value in different growth phase.The optimal growth conditions of WLZ-H strain were:initial pH 7.0, KNO3 content 1.5 g/L, glucose content 40 g/L, temperature 31 ℃.
Research on Chemical Experiment for Leptomitus lacteus Symboint Control
LI Tao, WANG Hai-yan, MENG Fan-jun, SUN Chun-bo, SONG Bo, ZHou Yue-xi, WANG Ye-yao
2011, 1(2): 137-144. doi: 10.3969/j.issn.1674-991X.2011.02.023
Abstract(5108) PDF(1055KB)(1345)
Abstract:
The chemical agents of potassium permanganate, chlorine dioxide, copper sulfate and caustic lime were used to study their effects on the growth activity of Leptomitus lacteus symbiont. The variation of microbial biomass of Leptomitus lacteus symbiont before and after dosing the chemical agents was used to reflect the control effect. The water quality variation in water solution of Leptomitus lacteus symbiont before and after dosing the chemicals and the cost of them were analyzed. The results show that the four chemical agents all have some control effects on Leptomitus lacteus symbiont, and when their dosage were 1.5,1.5,2.0 and 40 mg/L, the maximum decrease rate of Leptomitus lacteus symbiont were obtained, being 68.0%,63.1%,67.0% and 76.8%,respectively. According to comprehensive comparison of the control effect on Leptomitus lacteus symbiont, the cost and the water quality variation before and after dosing the chemical agents, the sequence of the four chemicals for emergency from good to bad is chlorine dioxide>potassium permanganate>copper sulfate>caustic lime; while the sequence of treating after collection is caustic lime> potasslum permanganate>copper sulfate>chlorine dioxide.
Research on Change of Biotic Community Structure in A/O MBR Process
CHEN Xiao-gang, ZHANG Hong-lin, YU Bing, ZHU Qiong-fang, ZHANG Juan, ZHAO Xiao-feng
2011, 1(2): 145-150. doi: 10.3969/j.issn.1674-991X.2011.02.024
Abstract(4244) PDF(806KB)(1458)
Abstract:
An anoxic-oxic membrane bioreactor (MBR) combination technology was used for treating campus domestic sewage. The sludge samples were collected every 24 hours to analyze the structure of biotic community and species composition in different periods. Meanwhile, the indicators of the sewage effluent and sludge quality were monitored and the relationship between biotic community structure and the removal rates of CODCr, NH4+-N and TP were studied. The results showed that during the running time, the flocculate structure of activated sludge changed among close-loose-tight-bulking, and the number of filamentous bacteria gradually increased, changing from 0 level, ±level, + level to ++ level.The change of the fauna community-Vorticellidae,Rotifera,Epistylis insects was found to have relation with sludge structure, and so the fauna community could be used as the indicator of sludge bulking as well as the time point of sludge discharging. The population size of microfauna and dominant fauna varied with the water quality, and the population of Sessile Vorticellidae,Cyst and Epistylis could be used as the bioindicator of CODCr concentration of the effluent.The dynamic relationship between the removal rates of NH4+-N,TP and microfauna community structure was not significant.
Air Pollution Control Technology and Usage of Clean Energy
Process Study of Molybdenite Roasting in Pure Oxygen Pressure Reactor
DU Ji-jun, TIAN Gang, ZENG Ping, LIU Yu, SHI Ying-jie, ZHANG Fan
2011, 1(2): 151-156. doi: 10.3969/j.issn.1674-991X.2011.02.025
Abstract(4807) PDF(667KB)(1850)
Abstract:
In an oxygen enriched pressure reactor, it was very important to present the molybdenite oxidation process using the curve about temperature and pressure. However, the measured temperature value could not reflect the gas temperature in reactor because of the influence of radiation and temperature rising. It was thus necessary to make a calibration to get the real gas temperature in reactor. An equation relating with environmental temperature, measured temperature and calibration temperature was set up based on the thermal equilibrium and general gas law. The parameters A and B were calculated through the empty reactor roasting experiment. As a result, the method of calibration temperature decided by the change of environmental temperature and the top measurement temperature of reactor was set up. The results showed that the equation fitted well with the real gas temperature. The relationship parameter R2 was 0.915 in empty reactor roasting experiment. The molybdenite roasting process in an oxygen enriched pressure reactor was analyzed by this calibration method. The oxygen temperature was found to decrease during molybdenite oxidation in an oxygen enriched pressure environment. The reaction started obviously when the pressure was 0.262~0.276 MPa and temperature was 456~481 K.
Study on the Process of Roasting Vulcanized Molybdenum to Produce Molybdenum Oxide with Pure Oxygen in the Obturation Dry Condition
TIAN Gang, DU Ji-jun, ZHANG Fan, LIU Yu, SHI Ying-jie
2011, 1(2): 157-161. doi: 10.3969/j.issn.1674-991X.2011.02.026
Abstract(5526) PDF(561KB)(1933)
Abstract:
Molybdenum oxide is an important raw material for steel and chemical industry. The conventional molybdenum oxide producing processes include reverberatory furnace roasting technology, rotary kiln roasting technology, multiple hearth furnace roasting technology, fluidized-bed roasting technology. In these conventional processes, the product quality was low with high concentration of SO2 (up to 2%) which was hard to be utilized and disposed, and could result in serious environmental pollution. An effective technology of roasting vulcanized molybdenum to produce molybdenum oxide with pure oxygen in the obturation dry condition was introduced, which could reduce the environmental pollution of SO2 and improve the quality of reaction product. Pure oxygen and molybdenum sulfide were roasted in the obturation dry reactor, with heating temperature less than 650 ℃ in the bottom part, the gas pressure in the reactor less than 0.4 MPa, the oxidizing reaction time between 35 and 50 minutes, and with the highest gas temperature 255 ℃.The results showed that the content of MoO3 in reaction product reached 93%, higher than that of the reaction product with the common productive technology (80%-85%), and the concentration of SO2 in flue gas was above 50% (in weight), thus having great practical value for utilization. The experiment proved that the new technology was feasible for MoO3 and SO2 recovery.
Comparison of the Absorption and Desorption Characters of Activated Carbon Fiber and Granular Activated Carbon on Benzene, Toluene and Xylene Mixed Gas
ZHANG Zhi-hong, CHEN Ning, YE Cui-ping, XIE Hua-qing, DAI Run-sheng
2011, 1(2): 162-167. doi: 10.3969/j.issn.1674-991X.2011.02.027
Abstract(7141) PDF(663KB)(2755)
Abstract:
The atmospheric pollution and indoor environment pollution generated from benzene, toluene and xylene (BTX) of widely used in paint and coating had been widely concerned with. Adsorption and recycling treatment technologies as effective means of pollution control and solvent recovery were still the research focus. To explore simple, low-energy consuming and easy-to-disseminate test means for evaluating absorption and regeneration performance of adsorption materials was in favour of their industrial applications and dissemination in indoor air cleansing. Based on the simple, low-energy consuming and easy-to-disseminate principle, the experiment used self-made glass adsorption tube to perform tube adsorption and thermal desorption, and to carry out comparative tests on desorption and regeneration characters of BTX mixture with Viscose-based activated carbon fiber (VACF) and Granular coconut-shell activated carbon (GAC) as the adsorptive material, in combination with the analysis of thermal desorption and gas chromatography. The results showed that under room temperature, the adsorption rate of VACF was much better than that of GAC, with the usage of VACF less than that of GAC. Under constant temperature 120 ℃ and nitrogen purge rate of 50mL/min, the VACF showed a superior desorption rate with Benzene and Toluene than GAC. Moreover, it showed a lower desorption rate of Xylene from VACF than that from GAC.
Solid Waste Pollution Prevention and Recycling Technology
Disposal and Management of Waste TFT-LCD
GUO Yu-wen, LIU Jing-yang, QIAO Qi, LIANG Ji-jun, YANG Dong-mei, REN Qian
2011, 1(2): 168-172. doi: 10.3969/j.issn.1674-991X.2011.02.028
Abstract(5312) PDF(642KB)(3591)
Abstract:
The main parts of thin film transistor liquid crystal display (TFT-LCD) and environmental toxicity of liquid crystal materials were summarized. The toxicity characteristics of waste LCD in their leaching procedure, the route of their recycling and reuse, and the pollution problems were analyzed. Disposal technologies of waste TFT-LCD and related policies on their recycling and management both at home and abroad were reviewed, and on this basis the suggestions on waste TFT-LCD disposal and management were put forward.
Pollution Control Technology Evaluation and Planning
Factors Analysis of Gas Lift Height from Cooling Tower
DING Feng, LI Shi-bei, XING Ke-jia
2011, 1(2): 173-180. doi: 10.3969/j.issn.1674–991X.2011.02.029
Abstract(6147) PDF(814KB)(2017)
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Based on the atmospheric dispersion model from VDI3784 guidelines of Germany, the influencing factors of plume rising height from Cooling Tower according to the meteorological and source emission parameters were analyzed. The results showed that compared to the wind speed, atmospheric stability had more important influence on the plume rising height. With the stability changing from strong unstabitily (A class) to strong stabitily (F class), the plume rising height gradually decreased, and the average range was 764 meters. With the wind speed changing from small calm wind (1 m/s) to the strong wind (20 m/s), the average plume rising height reduced 509 meters. The different source parameters’ effect on the maximum rising height was very small, and the rising height was likely to reach the maximum in certain weather conditions. But the effects of source emission parameters on the average rising height and minimum height were more obvious. The most influential parameters were temperature and gas flow rate, and the average range was 418 meters and 213 meters, respectively. But the variation effect of relative humidity and liquid water content in the flue gas on the average rising height was not significant.
Discussion on the Criterion of the Evaluation Level in the water Environment Impact Assessment in Water Conservancy and Hydropower Project
XUE Lian-fang, CHEN Kai-qi, CAO Xiao-hong, LUO Yun-hong
2011, 1(2): 181-184. doi: 10.3969/j.issn.1674-991X.2011.02.030
Abstract(5189) PDF(527KB)(1480)
Abstract:
According to the characteristic of the water environment impacts, and combined with the engineering characteristic water-shed scale and functional requirements, the criterion of the evaluation levels in the water environment impact assessment in water conservancy and hydropower project was put forward, which was checked in different types and scales of hydropower projects. The results showed that the evaluation levels recommended by the criterion in the water environment impact assessment conformed to the actual requirements. The research could provide reference for effectively applying technical guidelines in surface water environmental impact assessment.