Yangcheng Lake, a typical fishery lake in the middle and lower reaches of the Yangtze River, is threatened by eutrophication. As the main performers of biogeochemical cycles, microorganisms affect the ecological stability of the lake. To study the structural characteristics of the microbial community in Yangcheng Lake and rivers entering Yangcheng Lake and the response relationship with environmental factors, the microbial community was categorized based on the contour of Yangcheng Lake, the major rivers entering Yangcheng Lake, and the pollution sources. The distribution characteristics of seven physicochemical indices were analyzed, including total organic carbon (TOC), total nitrogen (TN), total phosphorus (TP), water temperature (WT), pH, dissolved oxygen (DO), and ratio of total nitrogen to total phosphorus (TN/TP). Characterization of microbial community structure based on 16S rRNA high-flux sequencing technology and ANOSIM analysis were used to explore the differences in the relative abundance of microorganisms at each sampling point in the lake and rivers, and redundancy analysis (RDA) was used to analyze the relationship between the microbial community and physicochemical factors. The results showed that the dominant phyla, genera of microorganisms, and the total number of OTUs in the lake and rivers were similar. The dominant phyla included Proteobacteria, Actinobacteria, Bacteroidetes, Cyanobacteria, and Verrucomicrobia; the dominant genera included the hgcI clade, CL500-29 marine group, Microcystis PCC-7914, Chloroplast_norank, Clade III_norank, and Flavobacterium . ANOSIM analyses revealed that the microbial community of Yangcheng Lake exhibited an association with geographical space, while the microbial community in the rivers that was linked to the type of pollution source. Redundancy analysis (RDA) indicated that dissolved oxygen (DO), total nitrogen (TN), and pH were significantly correlated with the dominant phyla in Yangcheng Lake ( p < 0.05), while total nitrogen (TN), water temperature(WT), and the ratio of total nitrogen to total phosphorus (TN/TP) were significantly related with the dominant genera in Yangcheng Lake ( p < 0.05). Total nitrogen (TN) was also significantly linked to the dominant phyla and genera of the tributaries ( p < 0.05). Despite the structural similarities in microbial communities between Yangcheng Lake and its inflowing rivers, environmental factors demonstrated significant associations with these communities, providing crucial data support for pollution prevention and the ecological restoration of Yangcheng Lake.
Taking an improved A~2/O process in northern China(with a design scale of 6×10~4 m~3·d -1 ) as an example, the relationship between carbon source storage and biological nitrogen and phosphorus removal was investigated based on the operation data of a whole year, and the utilization efficiency of carbon source and energy consumption was analyzed. The results showed that from July to September, the comprehensive utilization efficiency of carbon source reached 53%～55%, which proved that more than 50% consumed carbon source was used for biological nitrogen and phosphorus removal. Denitrifying bacteria were more sensitive to environmental changes than phosphorus accumulating bacteria. The extension cost of additional carbon source accounted for 20.5% of the direct cost. It was pointed out that the sewage treatment plant should fully consider the influence of the change of inlet and outlet water quality and environmental conditions on the effective utilization of carbon sources, so as to provide technical guidance and reference for the regulation and operation of municipal wastewater treatment plant with A~2/O process and other conventional processes.
In order to effectively deal with a large number of intermittent VOCs generated in the production process of the pharmaceutical industry, a direct catalytic combustion process of multi-effect heat recovery composed of heat storage, heat exchange, heat recovery and heat supplement was constructed. Combined with the fuzzy PID temperature control strategy, 500 g·m -3 platinum-palladium alloy plated on honeycomb ceramic carrier was used as a catalyst to treat intermittent organic waste gas discharged from a pharmaceutical industry.As a result, the feasibility of this technology in processing intermittent organic waste gas discharged from the pharmaceutical industry was verified. The results showed that under the condition that the mass concentration of VOCs emitted by the pharmaceutical industry fluctuated greatly from 22 mg·m -3 to 6 293 mg·m -3 , the multieffect heat recovery in catalytic combustion process could stably and effectively purify the organic waste gas emitted by the pharmaceutical industry, and the VOCs emitted after purification. The concentration was less than 20 mg·m -3 , and the comprehensive treatment efficiency was more than 97%. with the increase of VOCs mass concentration, the treatment efficiency was close to 100%. Using this technology, the average annual operating cost of this process was 357 200 yuan, which was reduced by more than 27% compared with the traditional process. In conclusion, the multi-effect heat recovery in catalytic combustion process could effectively treat intermittent VOCs in the pharmaceutical industry, and this study can provide a reference for the treatment of intermittent VOCs in the pharmaceutical industry, and also for other industries.
Sewage treatment to meet the demand of recycled water quality is increasing, and the technology suitable for the situation in our country has yet to be optimized as it gradually explores limit of technology（LOT） of sewage nutrition removal. This paper constructs an improved system readiness level（SRL） evaluation method based on the existing technology readiness level（TRL） and algorithm matrix, and relies on the LOT alternative technology combinations related to the national "Water Pollution Control and Treatment Science and Technology Major projects" during the “11th Five-Year Plan”, “12th Five-Year Plan” and “13th Five-Year Plan” and other domestic and foreign alternative technology combinations that meet the requirements of LOT.By comprehensive quantitative evaluation of TRL and improved SRL, the current situation of the development of LOT technologies in our country is sorted out and 12 candidate technologies combinations are selected.Among the 12 selected LOT alternative technology combinations, the SRL value of “A~2O+Deep-Bed Denite Filters Technology ”, “A~2O+MBBR+Coagulation Technology ” and “A~2O+Self-acctive Denitrification Technology+BAF” can reach 0.8～1, reaching the stage of production, operation and maintenance, which can be directly applied in production and generate high application benefits in the market. While the cost of TN and TP per unit mass removal of the three technology combinations is high, and the core functional processes are mainly traditional reactor technologies. Most of the single technology TRL levels are above 7, and most of the improved SRL values are between 0.6 and 0.8, which are in the stage of system development and verification. The relevant technology combinations are improving product stability for real market promotion. And most alternative technology combinations make the great use of the properties of ecological technologies such as plants and wetlands, which not only realizes strong synchronous nitrogen and phosphorus removal, but also has the market advantage of low operation and maintenance cost, which has the potential to be popularized.. The LOT alternative technology combinations basically realize the cost optimization and low carbon and low consumption technology operation mode, and meets the needs of waste water reclamation and the improvement of ecological environment.
A novel configuration of micro-aerobic/aerobic reactor at a pilot scale of 3 000 m~3·d -1 （series Ⅰ and Ⅱ） was developed based on the original anaerobic tank of a sewage treatment plant in Hebei Procince. Aerobic granular sludge was successfully cultivated in continuous flow mode with low-concentration municipal sewage as substrate, and the morphology, structural characteristics, pollutant removal performance and microbial community structure changes of granular sludge were studied. Results showed that the granular sludge formed by the pilot system had clear outline, regular spherical and ellipsoidal shape, and the average diameter increased from 28.9 μm to 90.1 μm. Granules with diameters greater than 100 and 200 μm accounted for 47.8% and 9.4%,respectively. Moreover, the mechanical strength of granular sludge cultured in pilot system was much higher than that of inoculated sludge. The average NH 4 + -N concentrations in effluent of series Ⅰ and Ⅱ were 1.3 and1.0 mg·L -1 , respectively, and the average TN concentrations in effluent of series Ⅰ and Ⅱ were 9.9 and 9.1 mg·L -1 ,respectively. Thus the system had a satisfactory nitrogen removal performance. Furthermore, the highthroughput pyrosequencing showed a significant enrichment of Methylophilaceae and Methylotenera at genus level, implying that aerobic denitrification pathway might play an important role in nitrogen removal.
In order to explore the practical effect of low-carbon denitrification phosphorus removal process,the start-up study of the process was carried out in sequencing batch reactor （SBR）.The substrate flow acceleration rate was adjusted according to the substrate reaction rate under a condition of a temperature of （20±2）°C,a pH of （7.5±0.2）,and a dissolved oxygen （DO） content of 0.Denitrifying bacterial community that could use both nitrite and nitrate as electron acceptors was enriched and added into an anaerobic-anoxic-oxic （A~2/O） process to stimulate the denitrifying bacteria to play the biological phosphorus removal function in the reactor.The results revealed that after adding denitrifying bacterial this A~2/O process had obvious denitrification and phosphorus removal reaction,and the system ran stably.The average load of TP removal by denitrifying phosphorus removal was around 0.014 8 kg·（m~3·d） -1 .The average concentration in the anaerobic effluent reached 11.95mg·L -1 ,and the average ratio of anoxic phosphorus uptake amount to aerobic phosphorus uptake amount reached 2.40,that is the average denitrifying phosphorus removal rate was as high as 73.34%.This indicated tha the start-up of denitrifying phosphorus removal was achieved in this single-sludge A~2/O process,thus demonstrating the biological strengthening effect of denitrifying bacterial,and the comparative advantages of denitrifying phosphorus removal bacteria including Dechloromonas,Rhodobacter,Thermomonas,etc.This work proposed an available choice to take better advantage of DPAOs in a traditional activated sludge system to accomplish low-carbon biological nitrogen and phosphorus removal.
Anaerobic environment in drainage pipeline can produce methane（CH 4 ） and hydrogen sulfide（H 2 S）,while aerobic and anoxic environments will induce nitrous oxide（N 2 O）. Chemical oxygen demand（COD）,nitrogen（N） and sulfates(SO 2- 4 ) contained in wastewater are the major sources of these gases. The production mechanism of three kinds of harmful gases was systematically reviewed, and the effects of pollutants in wastewater, microorganisms in pipeline and pipeline environment on the production of harmful gases were identified. Based on this, the control strategies of these gaseous pollutants were respectively proposed.Among them, the inhibition measures of CH 4 and H 2 S were focused on adding chemical agents to the pipeline to limit the source control of production. However, the addition of NO - 3 /NO - 2 agents and oxygen injection might lead to large production of N 2 O, which was a kind of greenhouse gas. Therefore, it is necessary to fully understand the interaction between the complicated controlling factors in the dainage pipeline, so as to achieve the control of harmful pollution gases and chieve the goal of carbon reduction.
In this study, the heat modified water purification sludge(WTS 400-4 ) was prepared by 400 ℃ and 4 h pyrolysis using water treatment sludge as raw material. The adsorption characteristics of phosphate in water and the effects of different dosage（2.5%, 5%, 10%） on the controlled release and the form of phosphate in the sediment were discussed. At the same time, combining with SEM, BET and other characterization methods, the stabilization mechanism of WTS 400-4 on phosphorus in sediment was explored. The results showed that WTS 400-4 had more developed pore structure and specific surface area than WTS, which strengthened the phosphate adsorption capacity. The adsorption process conformed to the quasi-second-order kinetic model. Freundlich model was more suitable to describe the phosphate adsorption process on WTS 400-4 , the parameter n higher than1 indicated that the WTS 400-4 was easy to adsorb phosphate. The addition of WTS 400-4 could cause the transformation of the weakly adsorbed phosphorus（NH 4 Cl-P）, redox-sensitive phosphorus（BD-P）,organophosphorus（Org-P） and other readily released phosphorus to stable metal oxide bound phosphorus（NaOH-rP） in sediment, and the conversion amount increased with the increase of WTS 400-4 dosage, which could contribute to inhibiting the release of phosphorus from the sediment. In addition, the addition of WTS 400-4 could reduce the contents of WSP（water-soluble phosphorus） and Olsen-P（sodium bicarbonate extractable phosphorus） in the sediment. Adding WTS 400-4 to the sediment, on the one hand, could reduce the contents of potential active phosphorus and bioavailable phosphorus in the sediment and reduce the risk of endogenous phosphorus release from the sediment to the overlying water. On the other hand, the phosphorus in interstitial water could be directly removed through the adsorption on WTS 400-4 , so as to reduce the phosphorus concentration gradient between overlying water and interstitial water and inhibit the release of phosphorus from interstitial water to overlying water. The results showed that WTS 400-4 could be used as a sediment amendment to control the phosphorus content in water and sediment.
In order to explore the pollution status of FQs in marine sediments,a method was developed for the determination of 13 target fluoroquinolones antibiotics （FQs） in marine sediments by liquid chromatographytriple quadruple tandem mass spectrometry coupled with solid phase extraction （SPE-LC-MS/MS）.All FQs were isolated and quantified by LC-MS/MS under multi-reaction monitoring （MRM） mode.Results showed tha under the optimal conditions,the mass concentrations of all 13 targets were 0.5～100μg·L -1 ,and a good linear relation occurred between above concentration and the peak area ratio of target compound to internal contro standard compound with correlation coefficients higher than 0.99,the detection limit （MDL） of this method was0.003～0.03μg·kg -1 .The average recovery rates of blank spiking were in the ranges of 73.5%～124.6%and67.5%～118.5%with the relative standard deviations （RSDs） from 1.0%to 9.7%（n=7） with two spiked levels of1.0 and 10μg·kg -1 .The average recoveries of 13 FQs with spiking in the marine sediments in the Pearl River estuary samples were 67.7%～142.4%with RSDs＜10.2%（n=6）.This method was used to detect 13 kinds of FQs residues in marine sediment of a bay area in Guangzhou,pefloxacin showed the highest mass fraction of1.6μg·kg -1 ,ofloxacin,ciprofloxacin and enrofloxacin were following with the mass fraction of 0.7μg·kg -1 .The method could rapidly and accurately detect 13 kinds of FQs in marine sediments at the same time,and was suitable for the determination of 13 FQs in marine sediments.The research results can provide data basis and technical support for marine ecological environment protection.
To explore the effect of micro-nano aeration combined with Vallisneria natans（MAVS） on the remediation of polluted water bodies and the mechanism of microbial population regulation, a polluted water body in Hefei National Wetland Park was used as a remediation object, and the restoration effect of landscape water body by MAVS and the dynamic change rule of water quality and microbial population structure of this water body were investigated with the demonstration project experiment. The results showed that after MAVS remediation, the water quality of the polluted landscape water body was significantly improved, its DO increased gradually, and the COD, NH 4 + -N, TN, and TP decreased by about 50%, 85%, 75%, and 75%,respectively; the structural diversity of the substrate microbial community increased with the remediation process, and the structural composition of the dominant microbial population remained relatively stable, but its abundance changed with the remediation process. At the phylum classification level, the dominant phyla were Proteobacteria, Bacteroidetes, Acidobacteria, and Chloroflexi, of which the abundance of Proteobacteria and Bacteroidetes decreased with the restoration process, while the abundance of Acidobacteria and Chloroflexi increased gradually; at the genus classification level, the dominant genera were Rhodocyclus＿uncultured,Xanthomonadales Incertae Sedis＿uncultured, Alcaligenes uncultured and Bacteroidetes vadin HA17＿norank,their abundance decreased with the remediation process, and gradually increased after the remediation process stopped. With the remediation process, the abundance of the dominant microbial community in the substrate of polluted landscape water bodies showed the same trend as COD and the opposite trend of DO, but it had a certain time lag. It can be seen that the microbial community structure of the remediated water body changed with the remediation process and water quality characteristics, and COD was the largest contributor to the change of microbial community structure and abundance, DO and TP also had some influence on this change.The micro-nano aeration combined with Vallisneria natans could effectively remediate polluted water bodies and regulate the microbial population structure of the water body substrate, which has good value of popularization and application.
In view of the low utilization rate of O 3 in the treatment of phenol containing wastewater by the advanced oxidation technology at current, UV/O 3 /PS coupling system is proposed to improve the content of strong oxidizing substances in the reaction system and strengthen the degradation and mineralization of phenol substances in the wastewater; On the basis of exploring the phenol degradation rate, TOC removal rate, reaction influencing factors and active substances of various coupling systems, the potential and advantages of this system in degrading phenolic wastewater were further studied. The results showed that the UV/O 3 /PS system could completely degrade phenol within 15 minutes. Compared with the single UV/O 3 method or UV/PS method, the mineralization rate of phenols in water increased by 47.36% and 39.93%, respectively. Through analysis of various influencing factors, the appropriate dosages of O 3 and PS in the UV/O 3 /PS system were determined. It was found that the UV/O 3 /PS system had a wide range of adaptability to pH and HCO 3 - , which implied that this system had an extensive application value in the treatment of refractory wastewater. In addition,ESR analysis showed that the coupling system produced more ·OH and ·SO 4 - under the catalysis of UV than the single system, which had a promoting effect. Thus, the UV/O 3 /PS coupling process had a better performance on phenols degradation in a wide range of applications. The research results can provide a theoretical reference for the degradation of phenolic wastewater by UV/O 3 /PS coupling process.
To investigate the influence of the photosensitive properties of anthraquinone on the removal efficiency of anthraquinone-based Reactive Blue 19（RB19） by photocatalytic degradation, the graphitic phase carbon nitride/bismuth bromide oxide（g-C 3 N 4 /BiOBr） was used as the photocatalytic material, and light（vis）together with peroxydisulfate（PS） were introduced, and a synergistic catalytic oxidation system was built. The formation of semiquinone radicals（Q - ·） during the degradation process, and the mechanism of their participation and enhancement of the oxidation capacity were investigated. The effect of Q - ·-enhancement effect was investigated by single factor（material dosing, initial pH, initial mass concentration of RB19, PS dosing, and light intensity） analysis method. The toxicity of the degraded wastewater was assessed by the degradation kinetics method and LC/MS. The results showed that the formation of Q - · not only accelerated the activation of PS, but also enhanced the photocatalytic effect of the material due to its cyclic action with hydroquinone（H2Q）and quinone（Q）. Under the simulated sunlight（300 W）, at the catalyst dosage of 0.1 g·L -1 and the PS dosage of400 mg·L -1 , the long chain radical reaction initiated by Q - · in the process of deriving other free radicals enabled the system to completely degrade RB19 with initial concentration of 40 mg·L -1 within 80 min. The influence of the four factors followed the order: material dosage ＞ initial pH ＞ RB19 initial concentration ＞ light intensity.The significant reduction of wastewater toxicity after the reaction was mainly attributed to the formation of semi-quinone radical intermediates, which could effectively increase the content of free radicals in the system. In conclusion, the self-degradation, self-cycling and long-chain radical effect induced by Q - · within the system was the main reason for achieving an efficient degradation of RB19. The results of this study can provide a reference for the development and practical application of anthraquinone dyestuff wastewater treatment technology.
Ceramic membrane has been widely used in the field of oilfield produced water treatment in recent years because of its high mechanical strength, good chemical stability and other advantages. Aiming at the core issue of membrane pollution control in oilfield produced water treatment by ceramic membrane, the small-scale experiment and model analysis were used to deeply conduct the optimization research on the operation control of ceramic membrane treatment system. Combined with microscopic characterization, the membrane pollution mechanism in oilfield produced water treatment by ceramic membrane was clarified. The results showed that the optimal operating control conditions for oilfield produced water treatment by ceramic membrane were: initial membrane flux of 80 L·（m~2·h） -1 , filtering time of 10 min, backwashing time of 30 s, aeration intensity of 3 L·min -1 . Under above conditions, the ceramic membrane could maintain an average membrane flux of27.82 L·（m~2·h） -1 . The characterization results of raw water and pollution layer showed that amine or amide,hydrocarbon, carboxylic acid, aromatic, alcohol and other organic compounds were the main organics causing ceramic membrane pollution, and inorganic salt ions such as Si, Fe, Ca, Mg, Ba were also important components of membrane pollution; In the filtration process, both the resistances in the membrane pore and in the gel layer play a leading role in the formation of ceramic membrane fouling.
In this study, the efficiency of carbon source released from sludge by a ball milling-thermal alkali coupling method was investigated, and the feasibility of directly replacing the external carbon source with the cracking solution for denitrification was further explored, as well as the effect of this method on sludge reduction. The results showed that, for the sludge with concentrated water content of 93.8%, at the water bath temperature of 80 ℃, the compound alkali dosage of 154 mg·g -1 （calculated by sludge VS dry weight）, SCOD and COD in the cracking solution reached 2.013×104 mg·L -1 and 4.725×104 mg·L -1 after reaction for 24 h,respectively. As indicated by three-dimensional fluorescence spectra, the fluorescent organic substances in the sludge cracking solution were dominated by easily biodegradable tryptophan and microbial metabolic byproducts. Before and after sludge treatment, the TS decreased from 61.7 g·L -1 to 15.6 g·L -1 , and some ultrafine particles were recycled with the upper turbidity solution, and the sludge reduction degree reached 74.7%.VS decreased from 30.4 g·L -1 to 4.6 g·L -1 , and the removal rate of volatile organic matter reached 84.7%. As suggested by the particle size analysis results, the median particle size of the original sludge decreased from28.1 μm（ before pretreatment） to 12.6 μm, and fine particles with a particle size of about 2.5 μm were produced and suspended in the cracking solution. Subsequently, the upper turbidity solution after sludge cracking sedimentation was directly used as the carbon source. In the simulated denitrification experiment（with the potassium nitrate added externally as the nitrogen source）. Moreover, the removal rate of NO3--N was higher than 97.0% after continuous and stable operation of the reactor. As demonstrated by the above experimental results, the ball milling-thermal alkali coupling method is a tremendously efficient sludge reduction method.Aside from that, the cracking solution can be effectively used as the denitrification carbon source owing to the satisfactory effects of sludge reclamation and reduction. Altogether, it is a considerably promising sludge treatment and disposal method.
The Yangtze River basin, with 21% of its land area supporting more than 40% of China’s population and economic aggregate, plays an important role. The temporal and spatial trends of dissolved oxygen（DO） and oxygen consuming pollutants(COD Mn and NH 3 -N) of the Yangtze River Basin were studied, and the process of water quality restoration was analyzed through statistics and correlation analysis. The results showed that from2008 to 2018, the overall water quality of the Yangtze River Basin showed an improvement trend year by year.The total proportion of class Ⅰ～Ⅲ water quality in key sections increased to 95.9%, increasing by 3.4%.Among them, the annual average concentration of DO in key sections increased, and the number of sections greater than 7.5 mg·L -1 accounted for 85.7% in 2018, with the most obvious increase in the upstream. The annual average concentration of COD Mn was stable within the limit of class Ⅲ water. The average annual concentration of NH 3 -N showed a downward trend, and the proportion of sections lower than 0.5 mg·L -1 reached95.2%, with the most obvious decrease（13%） in the downstream. Correlation analysis showed that DO was negatively correlated with COD Mn and NH 3 -N, with correlation coefficients of-0.40 and-0.44, respectively.COD Mn was positively correlated with NH 3 -N, and the correlation coefficient was 0.36. NH 3 -N had become the main oxygen consumption pollutant in the water body of the Yangtze River Basin. Water DO recovery in the Yangtze River Basin was closely related to the reduction of oxygen consumption pollutants, especially the control of high concentration of NH 3 -N. Investment in urban environmental infrastructure in the Yangtze River Basin has accounted for more than 50% of the total country emission on average for many years. In 2018, urban sewage discharge in the Yangtze River Basin was 37.9% higher than that in 2008, the average sewage treatment rate increased by 23.3 percent, and the amount of untreated sewage decreased by 77.8 percent. Therefore, with the progress of water pollution control and treatment in China, oxygen pollution in the main water bodies of the Yangtze River basin has been effectively controlled and water quality has shown gradual improvement accordingly.
In order to prepare a kind of anode material with high conductivity, good biocompatibility and corrosion resistance, and improve the electricity generation performance of microbial fuel cells（MFC）, the reduced graphene oxide/stainless steel fiber felt（RGO/SSFF） was prepared using stainless steel fiber felt（SSFF）as the base by hydrothermal reaction method. Furthermore, the titanium dioxide/reduced graphene oxide/stainless steel fiber mat（TiO 2 /RGO/SSFF） was prepared by using powder sintering method of loading nano titanium dioxide（TiO 2 ） onto RGO/SSFF. SSFF（control）, RGO/SSFF and TiO 2 /RGO/SSFF were used as the anodes of MFC（the corresponding MFCS were named as MFC-CK, MFC-RG and MFC-TRG, respectively） to explore the effects of modified materials on the removal of oxygen-consuming organic matter and electricity generation performance of MFC in water. The results showed that: Compared with SSFF, RGO/SSFF and TiO 2 /RGO/SSFF had larger capacitance（Q were 413.9 and 446.9 mF, respectively）, smaller interfacial transfer resistance(R ct were 19.65 and 18.16 Ω, respectively), and higher exchange current density(i 0 were 1.56×10 -5 and 2.07×10 -4 mA, respectively); The maximum COD removal rate of MFC-TRG was 929.62 mg·（L·d） -1 . The stable output voltages of MFC-RG and MFC-TRG were 245 mV and 280 mV, respectively, which were 88.5% and 115.4% higher than that of MFC-CK. The power density outputs of MFC-RG and MFC-TRG were 337.50mW·m -2 and 472.03 mW·m -2 , respectively, which were 163.9% and 233.9% higher than that of MFC-CK. In conclusion, the modified RGO/SSFF and TiO 2 /RGO/SSFF anodes successfully improved the electricity generation performance of MFC, which can provide a reference for the subsequent research on MFC anode modification.
This work investigated the Pb and Zn migration and transformation of municipal solid waste incineration（MSWI） fly ash during the combination of dechlorination by water washing with cement kiln incineration.The samples from the combination of dechlorination by water washing with cement kiln incineration was analyzed according to HJ 781-2016 and HJ 657-2013.Results showed that 0.15%Pb and 0.015%Zn entered crystalline salt and 94.05%Pb and 93.17%Zn remained in the washed fly ash without changing their state after water washing.Combining water washing with cement kiln incineration,a small part of Pb and Zn entered the kiln formed an internal circulation in the kiln and preheater system.93.84%Pb and 81.38%Zn entered cement clinker.0.002 7%Pb released in the flue gas,and 0.001 4%Pb and 0.001 1%Zn remained into the kiln dust.Pb mainly existed in the forms of PbO and PbSiO 3 ,and Zn mainly existed in the forms of ZnO,ZnFe 2 O 4 and ZnAl 2 O 4 according to thermodynamic equilibrium calculation.The flue gas emission Index and the performance Index of cement clinker could fulfill the requirements of relevant technical specifications and standards,indicating that Pb and Zn could be well fixed in clinker by cement kiln incineration and the environmental risk could be well controlled.This work could provide some referential values for the optimization design of co-processing of fly ash by cement kiln.
为探究电化学阳极氧化技术降解水中甲萘威的效率和能耗,通过电化学氧化-自掺杂还原法制备了高活性亚氧化钛纳米管(Ti/Ti4O7-NTA)阳极,比较了其与Ti/Ti4O7、Ti/Ti4O7-PbO2-Ce阳极电化学降解甲萘威活性;考察了电流密度、甲萘威初始质量浓度、电解质种类、溶液初始pH等参数对甲萘威降解率的影响;分析了甲萘威电化学反应能耗和电流效率.结果表明:Ti/Ti4O7-NTA阳极电化学活性较高,电化学降解甲萘威效率和溶液总有机碳去除率可达96.1％和80.2％;在pH为3～11时,甲萘威降解率为88.8％～92.1％,降解率随电流密度增大而增大,随初始质量浓度增大而减小;甲萘威电化学反应能耗和电流效率分别为215.3 kWh和66.1％.由此可知,Ti/Ti4O7-NTA阳极应用于电化学氧化处理有机农药废水具有良好潜力.本研究成果可为电化学氧化技术处理有机农药废水提供参考.
In order to control the pollution of chlorinated hydrocarbons in groundwater, NH 2 -MCM-41 was prepared by copolymerization with 3-aminopropyltriethoxysilane（APTES） as the modifier. The structure of NH 2 -MCM-41 was characterized by XRD, SEM, TEM, BET and FT-IR, and its adsorption behavior towards1,2-DCA in water was studied. The results showed that amino groups substituted part of silicon hydroxyl groups, resulting in the rough pores, while slight change on the hexagonal stacking structure of NH 2 -MCM-41occurred. After modification, the specific surface area, pore volume and pore diameter decreased by about 10%,25% and 26%, respectively. The introduction of amino groups enhanced the affinity and adsorption capacity of NH 2 -MCM-41 toward 1,2-DCA, and the adsorption capacity increased from 11.75 mg·g -1 to 15.59 mg·g -1 with an increase rate of 32.68%. The kinetic fitting showed that at the initial stage, NH 2 -MCM-41 adsorbing 1,2-DCA was controlled by physical adsorption, and it was mainly controlled by chemical adsorption during the subsequent process. The fitting of particle internal diffusion showed that the particle internal diffusion process was the main speed control step. Isothermal adsorption fitting showed that the adsorption sites of NH 2 -MCM-41were evenly distributed, and monolayer and multilayer adsorption coexisted in the adsorption process. At 20 ℃and pH 7, NH 2 -MCM-41 presented the best adsorption toward 1,2-DCA. Humic acid（HA） and coexisting anions inhibited the adsorption of 1,2-DCA on NH 2 -MCM-41. Thus, NH 2 -MCM-41 could effectively adsorb1,2-DCA in water. The research results can provide a relevant reference for the treatment of polluted groundwater by chlorinated hydrocarbon.
In order to reduce the energy consumption and improve the nitrogen removal efficiency of biological nitrogen removal system for urban sewage, a new type of aeration-power lateral internal-circulation reactor（ALIR） was used to treat artificial urban sewage, and the nitrogen removal pathway and performance of the reactor was investigated. 16 S rRNA gene high-throughput sequencing technology was used to analyze microbial community structure. The results showed that at A/O ratio of 1:1, hydraulic retention time of 9 h,sludge age of 20 d and sludge return ratio of 100%, the effluent concentrations of ammonia and total nitrogen（TN） were as low as（3.20±0.93） mg·L -1 （92.29%, ammonia removal efficiency） and（11.68±1.31） mg·L -1 （71.81%, TN removal efficiency） after long-term operation for over 90 days, respectively, and the simultaneous nitrification and denitrification（SND） rate was 26.49%. The results of the high-throughput sequencing showed that the dominant phyla in the inoculated sludge and the activated sludge on the 80 th day were Proteobacteria and Bacteroidetes. Compared with the inoculated sludge, the relative abundances of denitrifying bacteria in the activated sludge on the 80 th day, such as Pseudomonas and Sulfuritalea, showed a decreasing tendency, while these of Acinetobacter and Hyphomicrobium with an aerobic denitrifying function increased significantly. Thus,the aeration dynamic transverse internal circulation reactor had a good nitrogen removal performance without the energy consumption of internal circulation under the experimental operating conditions. This will provide a reference for the application of this reactor in practical engineering.
