bluuebunny/crossref_metadata_2025 huggingface dataset:
Parametric method used for mapping the groundwater vulnerability to contamination
Authors: Buta C , Maftei C , Mihai G , Stănescu M
Published: November 2019

Groundwater is a natural resource indispensable for life and for most economic activities. Due to its presentation in time and space, groundwater becomes vulnerable to hazardous phenomena of different origin, natural or anthropogenic, that can produce disturbances in some water systems or default situations. Parametric models can be used to model the groundwater vulnerability and with the help of Geographical Information System (GIS) we can make the results of a complicated parametric model more clearly through visual representation. To achieve the above objective, the empirical model known as “DRASTIC” developed in USA by the Environmental Protection Agency (EPA) [1] as a way to produce a relative-risk scale of potential groundwater vulnerability to pollution that could be applied to a large area was adopted and tested with GIS to identify areas from Dobrogea Region (Romania) where the groundwater is more or less susceptible to pollution.
D8 flow model for pollutants dispersion: A case study at Bogdalen watershed between the Raudfjell and Kvitfjell wind farm, North of Norway
Authors: Bui M T , Lu J M
Published: November 2019

Investments in wind power are booming in Norway. Several wind power plants have been constructed to exploit the wind energy. However, construction of wind farms has potential impacts on the surrounding environment. Particularly, waste from construction site or activities of workers, leakage of oil and chemical would spread into the nearby waterbodies by runoff or infiltrating into ground. Hence, quality of surface water and ground water would be degraded. Raudfjell and Kvitfjell is the biggest on-shore wind power project in the north of Norway and is underconstruction. However, water quality around these two wind farms has been reported to be seriously polluted. The pollutants in the water are expected to disperse to surrounding area by runoff and accumulate at certain accumulation areas in the watershed. Therefore, it is of great importance to identify the directions of pollutants transportation and the potential vulnerable areas that may be affected by the pollution. This paper built up a D8 flow model to investigate pollutants dispersion at the small-scale watershed Bogdalen located between Raudfjell and Kvitfjell wind farm area. The model identified in detail possible single-flow directions on each cell of ground surface and detected the potential pathways where pollutants are expected to transport to and accumulate. The results stated that the model has provided promising results for pollution management.
Pb2+ biosorption on Sargassum ilicifolium in the presence of Na+ and quaternary ammonium cations
Authors: Caparanga A R , Roque M B M , Alday L M , Santos N D
Published: November 2019

Quaternary ammonium cations (or quats) and Na+ were used as model interfering ions that could possibly influence the uptake of Pb2+ in wastewater by dead algal biomass of Sargassum ilicifolium. This biosorption study consisted of four sets of batch experiments: Pb2+; Pb2+/Na+; Pb2+/quats; Pb2+/Na+/quats. The effect of the presence of ions other than Pb2+ on the maximum extent of adsorption on the biomass was determined. Equilibrium data gathered suggested that improved Pb2+ adsorption could occur in the presence of quats. On the other hand, the presence of Na+ lowered the maximum extent of adsorption of Pb2+, particularly at low initial concentrations of Pb2+. In the presence of both Na+ and quats, more Pb2+ were adsorbed than when only one type of interfering ions was present.
Dispersion and diffusivity of halloysite and bentonite nanoclays in aqueous Pb (II): Effect of particle concentration, temperature, and pH
Authors: Tagalog C J L , Caparanga A R , Millare J C
Published: November 2019

This study investigates the influence of particle concentration, temperature, and pH to the dispersion properties and diffusivity of nanoparticles – halloysite and bentonite nanoclays in water, with and without the presence of lead (II) ions. Light scattering analyses were conducted to observe the changes on hydrodynamic radius, zeta potential, and diffusion coefficient of the nanoparticles. Results showed that with the increase of particle concentration and as pH increases, the average hydrodynamic radii for the two nanoclays seems to decrease, and were much smaller in the presence of Pb (II) ions. Conversely, the size of the nanoparticles appears to increase as temperature increases for the halloysite sample while the opposite was found for the bentonite dispersion. Sizes increase and decrease even more upon Pb (II) additions for the halloysite and bentonite dispersions respectively. In terms of zeta potential, both lead-free nanoparticles showed a more negative surface net charge as concentration and pH increases indicating an improvement in suspension stability. This was not the case with respect to temperature changes where halloysite dispersions become more unstable. Pb (II)–bentonite samples on the other hand exhibit a rather unpredictable trend in the zeta potential as the temperature increases but were both more stable than pure bentonite. Lastly, the diffusion coefficients were obtained and data suggest that temperature has the highest influence among all parameters while the addition of Pb (II) ions increases the overall diffusivities except for low-zeta potential dispersions.
Degradation of methylene blue utilizing cobalt-impregnated zeolite beta via sulfate radical-based advanced oxidation process
Authors: Osias J M L , Chen Y C , Lin D Y , Shih Y C , Caparanga A R , Chen B H
Published: November 2019

Sulfate radical-based oxidation process (SRAOP) is an efficient way to completely degrade toxic dyes from wastewater. The purpose of this study is to utilize zeolite beta to support cobalt ions as a catalyst for such application. Zeolite beta was synthesized hydrothermally with SiO2/Al2O3 ratio of 30. Cobalt was impregnated into zeolite beta via wet impregnation method, with cobalt loading of 2wt% and 5wt% Co2+/zeolite beta. Catalyst characterization was done by XRD, ICP, SEM-EDS, FT-IR, BET, and TPD. Methylene blue was used as model dye to investigate the catalytic capability of the catalyst. The set up for the batch reaction was a 500 mL beaker containing 200 mL of 100 ppm dye mechanically stirred at 300 rpm. Oxone concentration was 2mM and the catalyst loading was varied with concentrations of 0.1, 0.5 and 1 g/L. UV-vis was employed to determine the concentration of dye remaining in the solution. Catalyst particle size ranged from 150 to 300 nm with BET surface area of 576.2 m2/g. The dye exhibited adsorption activity to the zeolite, where 92.4% of the dye were adsorbed after 2 hours. Degradation capability of the catalyst was satisfactory, reaching 100% removal after 45 minutes. The study showed that utilization of zeolite beta as a support for cobalt shows promising results for SRAOP application.
Adsorptive removal of Ni2+ ions in wastewater using electrospun cellulose acetate / iron-modified nanozeolite nanostructured membrane
Authors: Tolentino M S , Aquino R R , Tuazon M R C , Basilia B A , Llana M J , M C Cosico J A
Published: November 2019

Release of heavy metal contaminated wastewater is one of the major problems being encountered by many industries due to its hazardous effect on the ecosystem, specifically its negative impacts on human health. Although essential in small quantities, nickel (Ni) and other heavy metals could be very dangerous to human health when uptaken at high concentrations. In this regard, this undertaking focused on the fabrication of nanofibers of cellulose acetate (CA) with varying concentrations (0, 1.0, 1.2 and 1.4 wt%) of iron-modified nanozeolite (Fe-MNZ) through electrospinning technique for the adsorption of Ni2+ ions in simulated wastewater. The membranes produced underwent different characterization techniques to determine the effect of Fe-MNZ addition on the nanofibers. FTIR result showed changes in the broadness of some bank peaks which signifies the interaction between CA and Fe-MNZ. SEM results showed increasing fiber diameter with increasing Fe-MNZ concentration having an 848.08 nm maximum diameter. Lastly, Freundlich isotherm and pseudo-first order kinetics govern the adsorption of the Ni2+ ions, with the highest adsorption capacity of 7.46 mg Ni2+ / g membrane.
Environmental capacity assessment for Amoni and TSS in Dung Quat Bay, Viet Nam
Authors: Bui L T , Ho K P T , Vuong T A T
Published: November 2019

Vietnam has a more than 3,260 km coastline. It discharges anually to the marine about 847 billion m3 of water and over 250 million tons of sediment, accompanied by a large amount of nutrients and pollutants. However, the general assessment problem environmental capacity and carrying capacity of water bodies are still not paid attention in. In this study, carrying out an assessment of environmental capacity in Dung Quat Bay where many economic activities are taking place and negatively impact on the coastal environment. The combination of calculating the environment capacity proposed by Group of Experts on the Scientific Aspects of Marine Environmental Protection (GESAMP) and tissue hydrodynamics and water quality modeling pakegae Mike21 has conducted environmental capacity assessment according to two typical seasons of the study area. The results show that, in the dry season, if compared with the standards of aquaculture, aquatic conservation, NH4
+ is no longer able to bear the load; however, compared to water standards for beaches and water sports, NH4
+ still has the capacity to bear the load of 0.029 (ton/day) and 2,231 (tons/day) at low and high tide, respectively. With TSS, it can withstand about 7 tons to 370 tons per day corresponding to low tide and high tide in the dry season. Moreover, in the rainy season, NH4
+ is no longer able to bear the load in all cases; TSS also has environment capacity of about 160 (tons/day) at the low tide and 660 (tons/day) at the high tide.
River flow pattern and heavy metals concentrations in Pasig River, Philippines as affected by varying seasons and astronomical tides
Authors: Paronda G R A , David C P C , Apodaca D C
Published: November 2019

This study explored the transport of metal pollutants in Pasig River, an important source of water for different uses in the National Capital Region of the Philippines. In particular, the study investigated the effect of varying seasons and varying levels of tides on the flow pattern and heavy metals concentrations in Pasig River. Pasig River is one of the main outlets which drain directly into the Manila Bay and Laguna de Bay. Four sampling sites were chosen along the 27 km-stretch of Pasig River which includes the following: Delpan, Lambingan, Guadalupe and Kalawaan sampling locations. Series of water samplings were conducted during the months of April, 2007 copping the dry season and November 2007 covering the wet season. Sampling design was primarily based on the height of tide at Manila Bay. Flow rate as computed from surface flow velocity was measured at each station. Concentration of heavy metals such as cadmium, copper, lead and nickel, were also measured. Results indicate that an observable backflow occurred during the dry season when the tide was high, that is, saline water from Manila Bay, intruding into the Pasig River. Further, this study established that the highest flow rate was noted during the wet season at low tide, particularly at the Kalawaan station. On the other hand, low flow rate was observed during the dry season when the tide was high. With regard to the levels of heavy metals, concentrations were found to be elevated during the dry season and also, when high tide occurs. Water samples collected from Delpan station yielded high metal concentrations with lead (Pb) as the dominant heavy metal among the four metals analysed in this study. Variability in the metal concentration due to seasonal changes, varying flow patterns and tide may indicate water quality problems not only in Pasig River but also to coastal areas such as Manila Bay.
Ammonia removal mechanism by the combination of air stripping and ultrasound as the function of pH
Authors: Wu C-Q , Zhang Y , Chen X
Published: November 2019

Ammonia removal mechanism by the combination of airstripping and ultrasound (AU) as the function of pH was investigated. The synergistic effects were observed for air stripping and ultrasound, which was obviously enhanced with the decrease in pH. Ammonia degradation and ammonia stripping were the ammonia removal pathways by AU. Ammonia degradation was the main ammonia removal pathway at the pH of lower than 8, but at a higher pH, ammonia stripping was the main pathway. Air stripping strengthens ammonia degradation by ultrasound in two ways of providing reactive radicals and more cavitation bubbles for pyrolysis. Ammonia degradation depended on the oxidation of radicals at a pH of lower than 8 and did on pyrolysis at a higher pH. Ultrasound also strengthens ammonia stripping by increasing mass transfer coefficient and accelerating the shift of the equilibrium of free ammonia and ammonium ions, which resulted in more strongly strengthening effect at a lower pH.
Optimal allocation of water resources through artificial fish swarm algorithm: A case study in Haixing, China
Authors: Liu M Y , Luan Q H , Liu M , Gong A X , Hu H J
Published: November 2019

North China is a typical developing region where the conflict between large water demand and little natural water resources exist. Thus, scientifically optimizing the allocation of regional water resources is particularly significant in this area. In this study, Haixing County, China was selected as the research region. Then, regional optimization model of water resource allocation was established, of which the objective function aims at the maximum integrated benefit of regional social and economy. In this model, two forbidden red lines of water use amount and water use efficiency were considered as the constraints, and Artificial Fish Swarm Algorithm was applied to calculate the optimization of water resource allocation. In 2020, the p = 50% total water shortage is forecast as 0.747 × 106 m3 or 2.1%. The results show that the efficiency and benefits have been improved, which illustrates that the optimization allocation of water resources through Artificial Fish Swarm Algorithm is reasonable. The research could provide a crucial technical support for regional water resource management.
Monitoring and health evaluation of stormwater runoff processes: A case study of Handan metropolis, North China
Authors: Pei M T , Zhou Y Y , Luan Q H , Xiao W H , Wang F Q
Published: November 2019

Metropolitan areas are facing increasing environmental risks of urban flooding under changing climate and intensified human activities. Therefore, it is of vital importance to evaluate the health of processes of stormwater runoff in changing environment. In this paper, the health evaluation was conducted using an indices system integrating the Analytic Hierarchy Processes (AHP) and Key Performance Indices (KPI) methods. This system consists of four dimensions, i.e. rainfall, runoff generation, runoff routing and river retention, and 12 indicating indices, considering the impacts of urban development on water cycling processes. Case study was conducted in Handan metropolis, North China. Particularly, an extreme stormwater runoff event, i.e. "2017.06.21 Stormwater Event", one of the most severe and typical urban stormwater events recently, was analysed. Results showed that the processes of stormwater runoff in this study rest in a sub-health state. The production processes is the most critical link in the urban water cycling health assessment. This result maps out the problem of poor infrastructure construction in Handan metropolis. Methods and results of this study could help better understanding of urban stormwater management and could serve as a reference for health evaluation of urban flooding in other metropolitan areas.
Estimating urban suitable ecological land based on the minimum cumulative resistance model: A case study in Nanjing, China
Authors: Ye Y P , Wang S N
Published: November 2019

Intense transformation and conflicts between different land use types has occurred in the past decades and will still exist in the coming decades in China. Ascertaining the quantity and pattern optimization of urban ecological land is critical to guaranteeing urban ecological security and realizing urban sustainable development. In this study, Nanjing, a very famous city in the Yangtze River Delta in China, was selected as the case study to explore the land use changes from 1995 to 2017 and calculate the suitable amount of ecological land to meet the needs of its socioeconomic development. From 1995 to 2015, the proportion of ecological land in Nanjing dropped from 84.41% to 59.15%. Based on the minimum cumulative resistance model (MCRM), we designed four alternate scenarios to explore the optimal quantity and pattern of ecological land in Nanjing. By comparing the current land use status with the model simulation results, we proposed the suitable ecological land area for Nanjing should be no less than 3963km2, which is 56% of the total area of Nanjing. The land use strategies and the measures to protect ecological land in this study can provide a reliable reference for sustainable development of other highly urbanized regions in China.
Changes in intracellular and extracellular free polyamines during the growth cycle of Prorocentrum donghaiense
Authors: Liu Y , Zhao W H , Dong B , Li B , Yang X H
Published: November 2019

We used HPLC to measure the concentrations of free putrescine, spermidine, and spermine in cells and culture medium during the growth of Prorocentrum donghaiense. Spermine was the main intracellular free polyamines in Prorocentrum donghaiense. The intracellular concentration of free polyamines kept increasing during the growth cycle and the ratio of spermine to putrescine increased with cell density. Changes in the ratios of spermine/spermidine in Prorocentrum donghaiense, however, occurred before changes in cell density, suggesting that polyamines can regulate cell growth and replication. Putrescine was the most abundant free polyamine in the culture medium, followed by spermine and spermidine. Changes to the media polyamines contents implied that Prorocentrum donghaiense could absorb free polyamines from the culture solution as well as release free polyamines into the medium during different growth periods, especially during the decline phase. These results suggest that masses of dead algae in the population decline phase would release abundant free polyamines into the environment.
Study on water resources management in Henan Province based on principal component analysis
Authors: Li L J , Li S Y
Published: November 2019

This paper selects 11 indicators from three aspects of water resources environment, economy and society to construct the water resources management evaluation system, and uses the principal component analysis method for analysis. Through the comprehensive evaluation of the water resources management level of Henan province in the past three years, the water resources management level of Henan province is compared to promote its management level and improve the efficiency of water resources utilization. The results show that: 1. The water resource utilization level in Henan province is stable and improving. 2. Cities with best water resource management include Zhengzhou, Luoyang, Xinxiang and Nanyang, while cities with good water resource management include Kaifeng, Pingdingshan, Anyang, Jiaozuo and Xinyang. 3. The water resources management level and the economic development level correlation degree is big, and the social development level correlation degree is small.
Application of remote sensing time series for characterizing interactions between the vegetation and hydro-geomorphology in the high-latitude arid region floodplains
Authors: Ablat X , Liu G H , Liu Q S , Huang C
Published: November 2019

Floodplain hydro-geomorphology is the major factor for vegetation growth and biomass. Characterizing interaction between the vegetation and hydro-geomorphology is essential to better understanding river ecosystems in arid regions. In this study, considering the various hydro-geomorphological dynamics of floodplains, the study area was divided into four functional zones and spatialized lateral variations of the floodplain fluvial disturbance intensity, sediment erosion and deposition process, moisture dynamics and vegetation growth condition through Landsat and daily Moderate Resolution Imaging Spectroradiometer (MODIS) time series between 2010-2015. And analyzed the various interactions between floodplain vegetation and hydro-geomorphology in different floodplain lateral zones. Results shows that the highest vegetation NDVI values (>0.4) are distributed in the regularly static floodplain area where characterized regular flood inundation and has moderate moisture ability. Vegetation NDVI values in the frequency inundation, wet and highly dynamic floodplain area are mainly less than 0.2. Results indicate that different hydro-geomorphological processes dominated in floodplains, therefore plants and hydro-geomorphology interact each other in different ways from river to floodplain margins. Using remote sensing time series can be better characterizing the different interactions between floodplain vegetation and hydro-geomorphology. This study can help to better management of river ecosystems in the arid region floodplains.
Photodegradation of organic pollutants in wastewater with different morphologies of silver phosphate nanocatalysts
Authors: Niu J F , Zhang Z Q , Wang K , Shi W J , Yu X J
Published: November 2019

Photocatalyst can use the sunlight to photodegrade the environmental pollutants. In this article, AgNO3 and Na2HPO4 were used as raw materials to prepare different morphology Ag3PO4 nanocatalyst with different methods. They are solid phase method, hydrothermal method, conversion precipitation method and direct precipitation method. Four kinds of photocatalysts are donated as Ag3PO4-GX, Ag3PO4-SR, Ag3PO4-ZJ and Ag3PO4-ZH, respectively. The obtained materials were characterized by XRD, UV-VIS DRS, SEM and BET.XRD analyse results showed that the Ag3PO4 prepared by four methods have good crystallinity form sharp diffraction peak. UV-VIS DRS results showed that the band gap of four samples are 1.66 eV (Ag3PO4-GX), 1.91eV (Ag3PO4-ZJ), 2.13 eV (Ag3PO4-ZH) and 3.37 eV (Ag3PO4-SR), respectively. SEM results showed that the samples prepared by direct precipitation method and hydrothermal method make Ag3PO4 particles more uniform and the samples have better morphology, more porous and uniform distribution of particles. The surface area of the samples prepared by the four methods is in the range of 20-35 m2/g. The photocatalytic capacity of four Ag3PO4 were investigates by methyl orange, methyl blue and ofloxacin. The photodegradation experiment showed that the Ag3PO4 photocatalyst prepared by direct precipitation method exhibited best degradation efficiency under the visible light irradiation. The mechanism of the remarkable photocatalysis was also explored by determining the role of active radicals. The results showed that h+ was the main active oxidation species in the presence of aerobic degradation of levofloxacin, while ⋅OH active species had little effect on the degradation of pollutants.
Bioplastic production from wastewater sludge and application
Authors: Liu F , Li J , Zhang X L
Published: November 2019

Plastic is considered as one of the most useful materials in the world. Plastic products are utilized in almost any field such as industry, manufacturing, agriculture, and service. Although plastic products can meet the needs of human beings, they also cause environmental problems such as white pollution. The current utilized plastic is non-biodegraded. It suggests that they would remain in long time in the environment when they are Activated sludge (sludge is called for short) is generated during the wastewater treatment process in large quantity. Its management gradually becomes a great problem. The problem of difficult recycling of plastic waste has attracted more and more attention. Recycling technology is an effective but incomplete measure to address these environmental issues. Based on this, bioplastics can solve this problem as a new material. Studies have found that high temperature lysates of sludge can be used to produce biodegradable plastic poly-3-hydroxybutyrate (PHB). And acetic acid produced by the anaerobic fermentation sludge thermal cracking solution can replace glucose as a carbon source to support the growth of microorganisms. In this way, the use of sludge thermal cracking fluid to produce bioplastic PHB can be achieved. In this paper, the development of bioplastics is introduced in the context of understanding the development of bioplastics. This paper also introduces the various types of bioplastics widely used at present, discusses the principle of producing bioplastics from activated sludge, and prospects the application prospects of bioplastics.
Radiation synthesis and heavy metal ions removal of cellulose microsphere based adsorbent
Authors: Du J F , Dong Z , Zhao L
Published: November 2019

A novel cellulose-based adsorbent was successfully prepared by radiation induced grafting of glycidyl methacrylate onto the surface of cellulose microspheres, followed by epoxy ring-opening reaction to introduce iminodiacetic acid disodium (IDA). The characterization of the obtained adsorbent was investigated in detail. To evaluate the adsorption performance of the novel adsorbent in comparison with commercial adsorbent D850, batch and column mode adsorption experiments against Cu (II) and Ni (II) were conducted. The equilibrium time for Cu (II) and Ni (II) were 20 and 30 min, which is much shorter than that of commercial adsorbent. The adsorption capacity of the adsorbent for Cu (II) and Ni (II) reached 96.90 and 111.11 mg/g, respectively. Applicability of the novel adsorbent on the actual wastewater generated from electroplating plants was also investigated. It was found that the novel adsorbent possessed a higher adsorption/desorption velocity and broadly similar adsorption capacity with the commercial adsorbent, signifying the effective adsorption performance of the developed grafted adsorbent.
Population exposure to large-scale heatwaves in China for 1961-2015
Authors: Zhao G N , Li B Z , Kong P , Xia L J , Zhan M J
Published: November 2019

According to the observed daily maximum temperature data from 756 climate stations in China during 1961–2015, the frequency, intensity, impacted area, and population exposure of the large scale heatwaves (HWs) are calculated by the Intensity-Area-Duration method. During 1961–2015, averagely 24.6 HWs happened every year with an average intensity of 34.4°C, impacting 4.71 million km2, around 49.1% of the territory of China. In 2000s, the HW frequency and impacted area have increased by 1.5 times and the intensity has increased by 0.3°C. The largest population exposure is in Central China. There are three stable high value centers of population exposure in China: Northwest China, Central China and North China. The northwest high-value-center is almost stable and isolated. As the north and central high-value-centers are becoming larger, they are likely to merge into one. In 2013, the abnormally strong and stable western Pacific subtropical high and the equally stable Qinghai-Tibet high are the main reasons for the severest HWs in the middle and lower reaches of the Yangtze River. Moreover, North China has started to be invaded by HWs. At the same time, the expansion of the central and north HW centers may involve more populated and developed areas with the threat of HWs. These will affect the social stability, the human health and sustainable development of the national economy.
Conceptual framework of hierarchical water demand
Authors: Hou B D , Yang R X , Wang J H , Xiao W H , Zhao Y , Wang H
Published: November 2019

Water resources demand analysis is one of the basic and core contents of water resources planning, allocation and management. Its mechanism analysis is the focus, hot spot and difficult point of future social water cycle research. Aiming at the problems of lack of mechanism of water resources demand analysis and the large forecasting results, Maslow’s hierarchical theory of demand is introduced into the field of water resources demand. Based on the characteristics of individual water demand mechanism, the mechanism and characteristics of human demand for water resources in the process of life, production and ecological construction are analyzed, and the hierarchical theory of water resources demand is established accordingly. The theory divides water demand from low to high into three levels: rigid demand, elastic demand and luxury demand, and combines water demand at each level into three levels: basic water demand, reasonable water demand and representational water demand. Finally, based on this theory, the water demand forecasting method is discussed. The research results enrich the theory and method of water demand prediction, and lay a theoretical foundation for scientific prediction of future water demand.
Study of high tide level changes in estuary area in response to coastline deformation in Wenzhou Bay
Authors: Huang S C , Liu X , Zhao X
Published: November 2019

Wenzhou Bay, which is located in the southern coast of China with rich tidal flat resources, is frequently influenced by human activities, leading coastline deformation and high tide level changes in estuary area. A two-dimensional tidal numerical model of high resolution including Wenzhou Bay and East China Sea was established based on the MIKE21 FM model. The model was calibrated with field data and then was employed to predict high tide level changes under the development plan of coastline deformation. According to the simulating results, high tide level and tidal range in the Ou River and the Feiyun River estuary area will decrease about 0.01~0.13 m and 0.01~0.18 m, whether in dry season or flood season. Further analysis from tide wave point illustrates that weaken of the tidal system outside estuary area will occur after the coastline deformation. The direction of tidal propagation will change from vertical to parallel to coastline, causing weaken reflection, leading to the decreases of tidal range and high tidal level.
Characteristic on pollutant removal and extracellular polymeric substances distribution in different periods of an up-flow biological aerated filter
Authors: Ren J H , Cheng W , Wan T , Meng T , He M X , Wang M
Published: November 2019

The up-flow biological aerated filter (UBAF) reactor was established to explore the pollutant removal and the extracellular polymeric substances (EPS) distribution at the initial stage of biofilm, maturity of biofilm, and stable operation periods. The parallel factor (PARAFAC) model was applied to analyze the three-dimensional fluorescence characteristics of EPS. Canonical correlation analysis (CCA) was used to study the correlation between the distribution of EPS and pollutant removal. The results showed that the removal efficiency of chemical oxygen demand (COD), ammonia nitrogen (NH4
+-N), and total phosphorus (TP) at the maturity of biofilm were higher than other periods, and reached to 95.68%±0.87%, 73.48%±4.32%, and 63.80%± 14.27%, respectively. The operation period had a significant correlation with EPS distribution. All of biofilm samples detected four kinds of fluorescent substance of tryptophan-like (C1), protein-like (C2), humilic acid (C3), and humic acids-like (C4). The CCA result showed that NH4
+-N removal had a very significant positive correlation with EPS concentration and composition (R≥0.9261).
Analysis of runoff variation characteristics in Yishuhe River Basin
Authors: Zhao Y H , Yu B K , Qu P , Li S , Zhan D Q , Wang X Q
Published: November 2019

Yishuhe River Basin is located in the northeast of the Yishusi River Basin, with the watershed area of about 18200 km2. It is necessary to analyze the variety characteristics of runoff in Yishuhe River Basin, and it will provide technical support for flood control and drought relief. Based on the past continuous 60 years’ data of runoff measured at 2 hydrometric stations and precipitation at 23 precipitation stations in Yishuhe River Basin, this study analyzed the monthly and annual variation characteristics of the runoff in Yishuhe River Basin using some indexes and methods such as complete regulation coefficient and nonuniformity coefficient, concentration ratio, concentration period, Man-Kendall trend test and mutation detection, and so on. The research results indicate that the distribution of annual runoff in Yishuhe River Basin is uneven, the monthly maximum precipitation occurs in August generally, and the continuous four months’ runoff even accounts for 80% of that of the year. The annual runoff shows a decreasing trend with time at Linyi station in Yihe River and Daguanzhuang station in Shuhe River, and the tendency of runoff reduction is significant in Yihe River with an abrupt point happening in 1966 and 2013.
Extraction of protein from excess sludge by thermal pretreatment assisted enzymatic hydrolysis
Authors: Gao J L , Wang Y C , Yan Y X , Yue Q C
Published: November 2019

In this paper, the hydrolysis conditions to extract protein from excess sludge by thermal pretreatment assisted enzymatic were studied. The optimum technological conditions were the sludge moisture content of 95%, thermal pretreatment temperature of 100 °C, heating time of 3h, initial pH of enzymolysis sludge of 11, enzyme dosage of 3000U/g dry sludge, enzymolysis temperature of 55°C and time of 3h. Up to 52.8% of the protein content of the sludge was extracted, and the dehydration performance of the hydrolyzed sludge was 87.46% higher than that of the original sludge. Therefore, thermal pretreatment-assisted enzymolysis can effectively extract protein from excess sludge and improve its dewatering performance.
Effect of wall normal velocity on velocity distribution in unsteady flow
Authors: Huang Y Q , Han Y , Chen J , Qiu L C , He X L
Published: November 2019

The effect of wall normal velocity on velocity distribution in unsteady flow has been investigated. We established a modified log-law model by adding the wake-term by Coles and deviation term together to depict the velocity deviation caused from classic log-low model. An empirical formula for deviation-correction factor α has been determined based on the present experimental data, and it yields a good agreement with other published experimental data. Experimental measurements of velocity distributions in unsteady open channel flows have been performed to prove this model.The cause of this addition was discussed and explained, and the theoretical velocity images from the improved model have been compared with the present data, they are well correlated.
Research on the emergency management pattern and adjustment system for urban waterlogging
Authors: Yang S Y , Jiang R G , Xie J C , Yu X , Liang J C , Lian Y N
Published: November 2019

Urban waterlogging events have become more frequent in big cities, causing a considerable economic loss and casualties. Waterlogging disasters exert increasingly severe influences on cities, which has become a research hotspot under changing environment. In view of that problem of insufficient information in the waterlogging emergency management, it is necessary to build emergency management pattern to adapt to the changing environment of urban waterlogging and design support emergency management pattern implementation of adjustment system. Through the process of "pre-event, in-event and after-event", a set of emergency pattern is designed to face the urban waterlogging event, which ensures that the management personnel could grasp the state of the occurrence of the event at each stage of the event and take countermeasures for the occurrence of the event quickly. The digitalization and visualization of urban waterlogging emergency management can be realized by using customized components, drawing knowledge map and designing adjustment system. According to the urban waterlogging emergency management pattern, the Beijing emergency plan component and the component based on similar historical case analysis are customized, and the functions of the components are realized through the integrated adjustment system. The application shows that emergency management adjustment system of urban waterlogging can realize the quick use of information, offer users customized waterlogging emergency management services, and provide the management with the support of effective emergency management decision. The results can provide conceptual and technical support for urban emergency management. It can also improve the timeliness of urban response and the level of urban flood control.
Fabrication of Ag/TiO2/Fe2TiO5 nanofibers by electrospinning and their enhanced photocatalytic activity
Authors: Yang F , Yu X J , Zhang T , Niu J F , Li J , Nie J K , Li J P , Yao B H
Published: November 2019

Herein, Ag/TiO2/Fe2TiO5 nanofiber composites with different contents of Ag were prepared using electrospinning with a calcining process. The structure and morphology of Ag/TiO2/Fe2TiO5 were characterized by TG-DTA, FT-IR, XRD, and SEM. The results shown that the organic template was completely decomposed at about 670°C. It can also find the rutile and anatase TiO2 coexisted in TiO2 nanofibers, but the peaks of anatase TiO2 disappeared in Fe2TiO5/TiO2. In addition, when Ag added in the Fe2TiO5/TiO2, the peaks of Fe2TiO5 and TiO2 have been strengthened greatly. It can conclude that the Fe3+ and Ag+ have an opposite effect on the crystal growing of the sample. In addition, the Ag nanoparticles (AgNPs) were well distributed in the surface of TiO2/Fe2TiO5. The UV-Vis DRS and electrochemical tests indicated that the light absorption and carries separation of Ag/TiO2/Fe2TiO5 were enhanced obviously. Since the surface plasmon resonance effect of AgNPs and synergistic effect, the as-prepared composite (the content of Ag was 3% mol) show a higher photocatalytic performance in degradation of Rhodamine B (RhB 99.6%) than that of pure-TiO2 and TiO2/Fe2TiO5.
Analysis of factors affecting small-scale farmland water conservancy construction based on the perspective of farmers’ subdivision
Authors: Xu L , Chen J
Published: November 2019

This paper uses the survey data of Baoying and Shuyang counties in Jiangsu Province to analyze the investment intentions and behavioral orientations of different types of farmers on the construction of small-scale farmland water conservancy facilities, and constructs a Logit measurement model to explain the factors affecting the farmers’ willingness to invest. The results show that: Farmers’ willingness to invest is positively correlated with whether they are village cadres or not, household agricultural income, block arable land area, demand for farmland water conservancy facilities, evaluation of village cadres, comparison with surrounding village water conservancy facilities, and whether there are government involvement projects. It is also negatively related to the age of the farmer, the proportion of the working population, and whether or not he/she participated in the investment.
Monitoring the internet public opinion of mountain flood disaster using big data analysis
Authors: Cao R J , Jiang R G , Xie J C , Wang J , Shi T L , Wen C C
Published: November 2019

The mountain torrent disasters have caused severe damage and loss of life and property to the society and the economy, which attract the public’s attention. Timely monitoring the characteristics and evolution of internet public opinion in mountain torrents is of significant impact on the emergency response and management. The primary objective of the paper is to analyze the time and spatial characteristics, attention key points, emotional trend and participants of the public opinion in mountain torrent disasters using big data and statistical analysis. The current situation is investigated and a prediction method using correlation analysis is proposed, which provides reference for decision makers to formulate response plans according to public opinion from internet. The data mining method is used to obtain relevant data based on microblog API interface, and the data is processed by statistical methods. Combined with the content analysis method, the characteristics of public opinion in mountain torrents are comprehensively analyzed, and the hotspots of public concern and the trends of public opinion are obtained. The results show that the eruption time of the public opinion coincides with the disaster occurrence time. From spatial characteristics analysis, the flood disasters in China mainly occur in the North China Plain, the middle and lower reaches of the Yangtze River, the Pearl River Basin, the Sichuan Basin, and the Northeast Plain. The public opinion attention degrees are highly positive correlated with the occurrence of mountain torrent disasters, and the correlation coefficient is 0.96. Citizens not only pay attention to the disaster situation and rescue work, but also focus on the improvement of the disaster prevention work. Public emotional trend is mainly based on expressing hope for a safe life, pity and sympathy for the victims, panic about the severity of the disaster, objective evaluation of the situation, as well as admiration and concern for rescuers, and suggestions on early warning education. As an opinion leader, People Daily has great influence on the internet public opinion. At different stages, participants should work together to maintain a healthy public opinion environment.
Molecular dynamic simulations and DFT calculations on the effects of four inhibitors on the scaling of CaCO3 molecules
Authors: Li C J , Zhang C Y , Liao K X , Zhang W P
Published: November 2019

Molecular dynamic simulations and DFT (with GGA and PBE functional) calculations were used to study two effects of four inhibitors on the scaling of CaCO3. The first effect studied was the determination of the occurrence of the occupation of a position of a CaCO3 molecule by an inhibitor molecule in the scaling of pipes. This phenomenon was shown to occur by the minimum distance between the scaling surface and the free molecules (the CaCO3 or the inhibitors). The binding energy between the surfaces and free molecules showed that the intensity of adsorption of the inhibitors on the surfaces is stronger than the adsorption of CaCO3 on the surfaces. The main connection mode between the inhibitor and the surfaces is an induction force (when the molecules are adsorbed on a Fe surface) or an electrostatic force and a hydrogen bond force (when molecules are adsorbed on a Fe2O3 and a calcite surface). The second effect studied in this work was the interaction between CaCO3 molecule and the carboxyl of the inhibitor molecules. The values of the binding energy illustrate that this adsorption can occur spontaneously. The calcium ion of the CaCO3 connects to the oxygen atom of the carbonyl of the carboxyl by a coordination bond. The carbonate ion of CaCO3 connects to the hydrogen atom of the carboxyl by a hydrogen bond.
Research on groundwater system identification in use of hydrological signals processing technique
Authors: Luo C M , Zhu B , Wu J H
Published: November 2019

Filtering techniques can be applied in processing hydrological signal identifying groundwater system. A series of groundwater table observation sequences in a coalmine was dealt with by use of recursive (IIR, Infinite Impulse Response) and non-recursive (FIR, Finite Impulse Response) filtering. The responding characteristics and dynamic patterns on the groundwater system were recognized by the correlation analysis. An identification model based on the Hammerstein-Wiener was applied to fit the data of measurement. The study shows that: (1) Three types of aquifer are divided according to their corresponding characteristics to the precipitation. Comparing the IIR and FIR filtering, the features of different scale filtering are summerized. (2) In nonlinear Hammerstein-Wiener model, the best fitting between simulation and measurement is up to 94.9%. The application of signals processing technique is a efficient approach to identify the groundwater system’s characteristics and patterns.
Experiences from wastewater treatment in the hilly areas in Sichuan
Authors: Liu X , Guo Y
Published: November 2019

In recent years, measures have been taken against rural environmental problems, and remarkable achievements have been made in the construction of sewage treatment facilities, but there are still some problems. This paper takes three small sewage treatment facilities in the hilly areas of Sichuan as the research object, through field research and data collection, statistical analysis and analysis of various facilities, combined with actual use, the corresponding optimization development proposals are summed up to optimize the utilization efficiency of the facilities and improve the living environment in the rural areas. The results show that the combination of A2O+MBBR is more suitable for the economy and performance at Sichuan hilly areas, but other options can be selected according to different situations to achieve the best results. At the same time, this paper points out some problems and provides reasonable corresponding suggestions for rural small-scale sewage treatment facilities from the aspects of technical mode selection, planning and design, construction and operation, etc., and provides a more practical and feasible optimization plan and reference for the region to control rural water pollution.
Self-adaptive improved PSO algorithm to solve optimal operation of cascade reservoir systems
Authors: Xiang Y Q , Mo L
Published: November 2019

The optimal scheduling problem of cascade reservoirs is an optimal control problem for a dynamic complex nonlinear system with a large number of constraints, which has not been satisfactorily solved so far. This paper presents a new improved particle swarm optimization (PSO) algorithm, which based on self-adaptive improvement of relative progress, to solve the problem of optimal scheduling of cascade reservoirs. The results obtained by the improved PSO algorithm are found to be encouraging when compared with PSO algorithm under similar test condition.
Synergetic effects of iron-carbon micro-electrolysis integrating with other technologies
Authors: Zheng S M , Wang X Y , Chen C H , Kong H
Published: November 2019

The combination of iron-carbon micro-electrolysis (ICME) technology and other technologies is an important development direction for the treatment of refractory wastewater, which could overcome the disadvantages of each technology and combine the advantages of each technology. The synergetic effects of ICME combined with Fenton process not only save the cost of adding reagents, but also significantly improve the efficiency of the combination treatment. The advantage from the combination of ICME with ozone is due to plenty of hydroxyl radicals coming from ozone decomposition, which enhances the complex contaminants removal. The synergetic effects of ICME integrated with biological process include mainly two respects. One is that the galvanic cells produced around the ICME could readily convert complex organic compounds to biodegradable substrates, which is conducive to the degradation of pollutants by microbes. Another one is that the iron ions released from ICME possess great capability to promote the performance of the microbes to treat wastewater, for instance, mineral nutrients for microbes, electron transfer mediator, and vital components of enzymes. Accordingly, the integration of ICME with other technologies has great application prospect for refractory wastewater.