Comparison between UV and VUV photolysis for the pre- and post-treatment of coking wastewater

In this study, ultraviolet (UV) and vacuum ultraviolet (VUV) photolysis were investigated for the pre-treatment and post-treatment of coking wastewater. First, 6-fold diluted raw coking wastewater was irradiated by UV and VUV. It was found that 15.9%-35.4% total organic carbon (TOC) was removed after 24 hr irradiation. The irradiated effluent could be degraded by the acclimated activated sludge. Even though the VUV photolysis removed more chemical oxygen demand (COD) than UV, the UV-irradiated effluent demonstrated better biodegradability. After 4 hr UV irradiation, the biological oxygen demand BOD₅/COD ratio of irradiated coking wastewater increased from 0.163 to 0.224, and its toxicity decreased to the greatest extent. Second, the biologically treated coking wastewater was irradiated by UV and VUV. Both of them were able to remove 37%-47% TOC within 8 hr irradiation. Compared to UV, VUV photolysis could significantly improve the transparency of the bio-treated effluent. VUV also reduced 7% more ammonia nitrogen (NH₄⁺-N), 17% more nitrite nitrogen (NO₂^--N), and 18% more total nitrogen (TN) than UV, producing 35% less nitrite nitrogen (NO₃^--N) as a result. In conclusion, UV irradiation was better in improving the biodegradability of coking wastewater, while VUV was more effective at photolyzing the residual organic compounds and inorganic N-species in the bio-treated effluent.     

Comparison between UV and VUV photolysis for the pre- and post-treatment of coking wastewater

In this study, ultraviolet (UV) and vacuum ultraviolet (VUV) photolysis were investigated for the pre-treatment and post-treatment of coking wastewater. First, 6-fold diluted raw coking wastewater was irradiated by UV and VUV. It was found that 15.9%–35.4% total organic carbon (TOC) was removed after 24 hr irradiation. The irradiated effluent could be degraded by the acclimated activated sludge. Even though the VUV photolysis removed more chemical oxygen demand (COD) than UV, the UV-irradiated effluent demonstrated better biodegradability. After 4 hr UV irradiation, the biological oxygen demand BOD₅/COD ratio of irradiated coking wastewater increased from 0.163 to 0.224, and its toxicity decreased to the greatest extent. Second, the biologically treated coking wastewater was irradiated by UV and VUV. Both of them were able to remove 37%–47% TOC within 8 hr irradiation. Compared to UV, VUV photolysis could significantly improve the transparency of the bio-treated effluent. VUV also reduced 7% more ammonia nitrogen (NH₄⁺–N), 17% more nitrite nitrogen (NO₂⁻–N), and 18% more total nitrogen (TN) than UV, producing 35% less nitrite nitrogen (NO₃⁻–N) as a result. In conclusion, UV irradiation was better in improving the biodegradability of coking wastewater, while VUV was more effective at photolyzing the residual organic compounds and inorganic N-species in the bio-treated effluent.     

Evaluation of the effectiveness of horizontal subsurface flow constructed wetlands for different media

Two media bed (gravel and Filtralite NR) were tested in a mesocosm to evaluate the removal of organic matter (as chemical oxygen demand (COD)),ammonia (NH4-N),nitrite,nitrate and solid matter (as total suspended solids (TSS)) for a synthetic wastewater (acetate-based) and a domestic wastewater.The use of Filtralite allowed average removal rates (6–16.8 g COD/(m2·day),0.8–1.1 g NH4-N/(m2·day) and 3.1 g TSS/(m2·day)) and removal effciencies (65%–93%,57%–85% and 78% for COD,NH4-N and TSS,respectively),higher than that observed in the experiments with gravel.The applied loads of COD,ammonia,nitrate and TSS seem to influence the respective removal rates but only for the treatment of domestic wastewater with higher correlation coefficients for Filtralite.Regardless the type of media bed and the type of wastewater,nitrate was completely removed for nitrogen loading rates up to 1.3 g NO3-N/(m2·day).There was no evidence of the influence of nitrate loads on the removal of organic matter.     

Evaluation of the e ectiveness of horizontal subsurface flow constructed wetlands for di erent media

Two media bed (gravel and Filtralite NR) were tested in a mesocosm to evaluate the removal of organic matter (as chemical oxygen demand (COD)), ammonia (NH4-N), nitrite, nitrate and solid matter (as total suspended solids (TSS)) for a synthetic wastewater (acetate-based) and a domestic wastewater. The use of Filtralite allowed average removal rates (6–16.8 g COD/(m2 day), 0.8–1.1 g NH4-N/(m2 day) and 3.1 g TSS/(m2 day)) and removal e ciencies (65%–93%, 57%–85% and 78% for COD, NH4-N and TSS, respectively), higher than that observed in the experiments with gravel. The applied loads of COD, ammonia, nitrate and TSS seem to influence the respective removal rates but only for the treatment of domestic wastewater with higher correlation coe cients for Filtralite. Regardless the type of media bed and the type of wastewater, nitrate was completely removed for nitrogen loading rates up to 1.3 g NO3-N/(m2 day). There was no evidence of the influence of nitrate loads on the removal of organic matter.     

活性炭吸附处理锂电池厂含酯废水及微波再生实验

采用活性炭吸附的方法对锂电池产生的含酯废水进行预处理,研究了吸附时间、初始pH值和活性炭投加量对废水COD去除的影响.吸附饱和后的活性炭用微波进行再生,考察了辐照时间、微波功率及再生次数对活性炭再生效果的影响.结果表明,当活性炭投加量为10g/L时,吸附60min,含酯废水的COD去除率为69.5%,可生化性从原水的0.05提高到0.25.当微波功率为420W、辐照时间为6min时,活性炭可被有效地再生,再生效率高达98.0%,活性炭损失率约为5.2%.再生前后活性炭的红外光谱图表明,活性炭表面官能团发生了变化,促进活性炭对污染物质的吸附.     

微波强化Fenton体系处理制药废水研究

为了实现高浓度制药废水的处理,采用微波强化Fenton氧化体系对污水进行预处理,考察了微波功率、微波辐照时间、催化剂用量和氧化剂用量对高浓度有机废水中有机物去除效果的影响。来水COD 39 760 mg/L,B/C为0.254,控制微波功率为200 W、微波辐照时间11 min,加入0.6 mol/L的Fe(NO_3)_3催化剂、30%H_2O_2 4 mL/L氧化剂,COD去除率可达62.41%,B/C由0.254升至0.619。实现有机物去除,提高污水可生化性。     

Achieving biodegradability enhancement and acute biotoxicity removal through the treatment of pharmaceutical wastewater using a combined internal electrolysis and ultrasonic irradiation technology

Actual pharmaceutical wastewater was treated using a combined ultrasonic irradiation (US) and iron/coke internal electrolysis (Fe/C) technology. A significant synergetic effect was observed, showing that ultrasonic irradiation dramatically enhanced the chemical oxygen demand (COD) removal efficiencies by internal electrolysis. The effects of primary operating factors on COD removal were evaluated systematically. Higher ultrasonic frequency and lower pH values as well as longer reaction time were favorable to COD removal. The ratio of biochemical oxygen demand (BOD) and COD (B/C) of the wastewater increased from 0.21 to 0.32 after US-Fe/C treatment. An acute biotoxicity assay measuring the inhibition of bioluminescence indicated that the wastewater with overall toxicity of 4.3 mg-Zn²⁺·L⁻¹ was reduced to 0.5 mg-Zn²⁺·L⁻¹ after treatment. Both the raw and the treated wastewater samples were separated and identified. The types of compounds suggested that the increased biodegradability and reduced biotoxicity resulted mainly from the destruction of N,N-2 dimethyl formamide and aromatic compounds in the pharmaceutical wastewater.     

Treatment of oilfieid produced water by anaerobic process coupled with micro-electrolysis

Treatment of oilfield produced water was investigated using an anaerobic process coupled with micro-electrolysis (ME), focusing on changes in chemical oxygen demand (COD) and biodegradability. Results showed that COD exhibited an abnormal change in the single anaerobic system in which it increased within the first 168 hr, but then decreased to 222 mg/L after 360 hr. The biological oxygen demand (five-day) (BOD5)/COD ratio of the water increased from 0.05 to 0.15. Hydrocarbons in the wastewater, such as pectin, degraded to small molecules during the hydrolytic acidification process. Comparatively, the effect of ME was also investigated. The COD underwent a slight decrease and the BOD5/COD ratio of the water improved from 0.05 to 0.17 after ME. Removal of COD was 38.3% under the idealized ME conditions (pH 6.0), using iron and active carbon (80 and 40 g/L, respectively). Coupling the anaerobic process with ME accelerated the COD removal ratio (average removal was 53.3%). Gas chromatography/mass spectrometry was used to analyze organic species conversion. This integrated system appeared to be a useful option for the treatment of water produced in oil fields.     

微波诱导催化氧化处理废光盘回收废水的研究

采用微波催化氧化处理废光盘回收废水,探讨了微波功率等因素对废光盘回收废水处理效果的影响,获得了最佳工艺条件:100mLCOD为4217mg/L的废水(初始pH=4)在微波功率为800W,辐射10min,活性炭用量1g,H_2O_2用量1mL,FeSO_4用量为0.08g的条件下,COD去除率达到93.7%。     

Treatment of oilfield produced water by anaerobic process coupled with micro-electrolysis

Treatment of oilfield produced water was investigated using an anaerobic process coupled with micro-electrolysis (ME), focusing on changes in chemical oxygen demand (COD) and biodegradability. Results showed that COD exhibited an abnormal change in the single anaerobic system in which it increased within the first 168 hr, but then decreased to 222 mg/L after 360 hr. The biological oxygen demand (five-day) (BOD5)/COD ratio of the water increased from 0.05 to 0.15. Hydrocarbons in the wastewater, such as pectin, degraded to small molecules during the hydrolytic acidification process. Comparatively, the e ect of ME was also investigated. The COD underwent a slight decrease and the BOD5/COD ratio of the water improved from 0.05 to 0.17 after ME. Removal of COD was 38.3% under the idealized ME conditions (pH 6.0), using iron and active carbon (80 and 40 g/L, respectively). Coupling the anaerobic process with ME accelerated the COD removal ratio (average removal was 53.3%). Gas chromatography/mass spectrometry was used to analyze organic species conversion. This integrated system appeared to be a useful option for the treatment of water produced in oilfields.     

一种复合菌制剂对富营养化污水的净化作用研究

以高效去除COD为主要指标,从南昌市区富营养化的鱼塘淤泥水和猪场废水混合液中分离筛选出4株目的菌株,发现其中以NCG1菌株的去除活性最好.经生理生化鉴定和16SrRNA序列分析,初步鉴定NCG1为施氏假单胞菌(Pseudomonas stutzeri).同时,采用另一株具有高效去除无机盐氮能力的菌株C-4与菌株NCG1复合培养,建立了两株菌的复合培养方法.结果表明,与单菌相比,复合菌综合了单菌的优良去除活性,在对合成废水的处理中,72h后废水中NH4+-N、NO3--N和COD的去除率分别达84.4%、86.91%和81.36%.研究表明,生产的复合菌剂在对富营养化池塘污水样品的处理中显示出良好的效能.     

餐厨垃圾水解酸化液作碳源的脱氮效果研究

针对餐厨垃圾水解酸化液作外加碳源的反硝化脱氮效果进行研究,考察了人工配水条件下水解酸化液反硝化处理的适宜COD/NO3--N比范围,在适宜COD/NO3--N比条件下与甲醇、乙酸钠的反硝化效果进行对比,并验证了水解酸化液对于生活污水的反硝化效果.结果表明,人工配水条件下利用水解酸化液作碳源的适宜COD/NO3--N比为4.9~6.0,反硝化速率最高可达25.0mg NO3--N/(gVSS·h).反应过程存在2个不同的硝态氮去除速率阶段,并出现了亚硝氮积累.餐厨垃圾水解酸化液为含多种VFA成分的混合物,其反应过程中硝态氮的去除速率比甲醇、乙酸钠等纯物质做碳源时的硝态氮去除速率快.将餐厨垃圾水解酸化液用于生活污水脱氮处理,当COD/NO3--N比为6时,水中的硝态氮以及亚硝氮均能够得到较为彻底的去除.     

The integration of methanogenesis with denitrification and anaerobic ammonium oxidation in an expanded granular sludge bed reactor

ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅＵＡＳＢｒｅａｃｔｏｒａｎｄｉｔｓｖａｒｉｏｕｓｍｏｄｉｆｉｃａｔｉｏｎｓｈａｖｅｂｅｅｎｓｕｃｃｅｓｓｆｕｌｌｙａｐｐｌｉｅｄｔｏｔｈｅｔｒｅａｔｍｅｎｔｏｆｖａｒｉｏｕｓｋｉｎｄｓｏｆｗａｓｔｅｗａｔｅｒ(ｈｉｇｈｔｏｌｏｗｓｔｒｅｎｇｔｈ ,ｉｎｄｕｓｔｒｉａｌａｎｄｄｏｍｅｓｔｉｃ)ｕｎｄｅｒｐｓｙｃｈｒｏｐｈｉｌｉｃ ,ｍｅｓｏｐｈｉｌｉｃａｎｄｔｈｅｒｍｏｐｈｉｌｉｃｃｏｎｄｉｔｉｏｎｓ(Ｌｅｔｔｉｎｇａ ,1995 ) .Ｍｏｄｅｒｎａｎａｅｒｏｂｉｃｒｅａｃｔｏｒｓ…     

纳米ZnO光催化剂的制备及性能研究

以Zn(CH3COO)2·H2O和NH4HCO3为原料,以室温固相反应和微波辐射技术相耦合的方法制备出粒径在19nm左右的ZnO光催化剂,同时以活性艳兰KN-R为模拟染料废水考察了所制备纳米ZnO的光催化性能。结果表明,所制备纳米ZnO具有良好的光催化活性,在适宜的操作条件下,活性艳兰KN-R的脱色率在96%以上,COD的去除率在69%以上。此外,在染料的浓度为30～100mg/L时,ZnO/UV体系光催化降解活性艳兰KN-R符合一级反应动力学模型。     

序批式移动床生物膜反应器内同步短程硝化反硝化的控制

在序批式移动床生物膜反应器(SBMBBR)内,对进水COD较低的条件下,模拟生活污水的亚硝化及脱氮性能进行了研究.结果表明,缺氧时间、进水COD、NH44 -N浓度、pH值以及溶解氧对亚硝化过程有明显影响.在进水COD为100mg·L-1NH4 4-N浓度为50mg·L-1时,调控溶解氧、pH,出水的亚硝化率可到99.7%,总氮去除率可达66.4%,表明系统中发生了同步短程硝化反硝化.     

Feasibility and advantage of biofilm-electrode reactor for phenol degradation

The new biofilm-electrode method was used for the phenol degradation, because of its low current requirement. The biofilm-electrode reactor consisted of immobilized degrading bacteria on Ti electrode as cathode and Ti/PbO2 electrode as anode. With the biofilmelectrode reactor in a divided electrolytic cell, the phenol degradation rate could achieve 100% at 18 h which was higher than using traditional methods, such as biological or electrochemical methods. Chemical oxygen demand (COD) removal rate of the biofilmelectrode reactor was also greater than that using biological and electrochemical method, and could reach 80% at 16 h. The results suggested that the biofilm-electrode reactor system can be used to treat wastewater with phenol.     

活性炭吸附-微波催化氧化处理番茄酱加工有机废水

采用活性炭吸附-微波催化氧化技术处理番茄酱加工有机废水,考察了活性炭添加量、H2O2用量、辐射时间以及微波功率对废水处理效果的影响。确定微波催化氧化条件为:微波功率630w、辐射时间15min、H2O2用量0.9mL、活性碳用量1.5g/100mL。在此条件下对废水进行处理,废水的COD、TOC和BOD去除率分别为87.3%,84.4%和82.3%,处理时间由2h缩短为15min。结果表明,该方法是一种快速有效的处理番茄酱加工有机废水的方法。     

微波协同活性炭处理甲基橙废水的研究

以粉末活性炭为催化剂,建立了微波协同氧化工艺,对模拟甲基橙废水进行处理。微波协同氧化、活性炭吸附和单纯微波辐射3种不同工艺的对比实验表明,微波诱导氧化工艺具有明显的优越性．考察了甲基橙浓度、微波功率、辐射时间、活性炭用量对甲基橙去除率的影响。在甲基橙质量浓度为305mg／L、微波功率580W、辐射时间10min、活性炭用量1．2g/L的条件下,甲基橙色度去除率为99．63％,COD的去除率为95．8％。     

The integration of methanogenesis with denitrification and anaerobic ammonium oxidation in an expaned granular sludge bed reactor

The integration of methanogenesis with denitrification and anaerobic ammonium oxidation (ANAMMOX) was studied in an expanded granular sludge bed (EGSB) reactor in this work. Experimental results from the continuous treatment of wastewater with nitrite and ammonium, which lasted for 107 days, demonstrated that wastewater with high nitrite and ammonium could be anaerobically treated in an expanded granular sludge bed reactor. More than 91% to 97% of COD were removed at up to about 3.9 g COD/(L x d) of COD volumetric loading rate. More than 97% to 100% of nitrite was denitrified at up to about 0.8 g NO2(-) -N/(L x d), which is 16 times higher than that in a conventional activated sludge system with nitrification/denitrification (0.05 gN/(L x d)). No dissimilatory reduction of nitrite to ammonium occurred in the process. However, maximum of about 40% ammonium was found to be lost. Batch tests of 15 days with sludge from the reactor showed that 100% of nitrite was denitrified completely, and about 3% of ammonium was removed when only ammonium (34.3 mg/L) and nitrite (34.3 mg/ L) were added into the sludge suspension medium. Furthermore, about 15% of ammonium amounts were lost with organic COD addition. It suggested that the methanogenesis in the system could enhance ANAMMOX because of intermediate hydrogen produced during methanogenesis.     

间歇曝气对硝化菌生长动力学影响及NO_2~-积累机制

采用间歇曝气方法处理低氨氮浓度生活污水,在SRT 10、 5、 2.5和1.25 d条件下,SBR反应器出水中NO-2含量(以N计,下同)为18、 19、 14和5 mg/L,积累率达到73%、 85%、 91%和78%,而连续曝气SBR仅为14%、 21%、 31%和34%;同时氨氮去除率维持在97%、 95%、 76%和39%,与连续曝气SBR的92%、 97%、 71%和47%相当.对硝化菌的生长动力学分析表明,在间歇曝气硝化系统中,氨氧化菌(AOB)可以通过产率系数(YAOB)的增加来提高自身在反应器中的绝对生物量,并补偿因间歇曝气引起的比底物利用速率下降,从而使比增殖速率(μm)和NH+4的氧化速率不变.与此相反,亚硝酸盐氧化菌(NOB)却不具备这种补偿特性,导致其μm和对NO-2氧化速率降低,引起了NO-2在出水中积累.