A pilot scale anoxic/oxic membrane bioreactor(A/O MBR) for woolen mill dyeing wastewater treatment

A pilot scale(10 m 3/d) anoxic/oxic membrane bioreactor(A/O MBR) was tested for dyeing wastewater treatment of woolen mill without wasting sludge in 125 days operation. Results showed that the effluent quality was excellent, i.e. effluent COD less than 25 mg/L, BOD 5 under 5 mg/L, turbidity lower than 0 65 NTU, and colour less than 30 DT, and met with the reuse water standard of China. The removal rates of COD, BOD 5, colour, and turbidity were 92 4%, 98 4%, 74% and 98 9%, respectively. Constant flux operation mode was carried out in this study, and backwash was effective for reducing membrane fouling and maintaining constant flux. Membrane fouling had heavy impact on energy consumption. More attention should be paid on pipe selection and design for the sidestream MBR system, too.

Organising a juvenile ratio monitoring programme for 10 key waterbird species in the Yangtze River floodplain:analysis and proposals

Background:In the face of continued degradation and loss of wetlands in the Yangtze River floodplain(YRF),there is an urgent need to monitor the abundance and distribution of wintering waterbirds.To understand fully observed annual changes,we need to monitor demographic rates to understand factors affecting global population size.Annual reproduction success contributes to dynamic changes in population size and age structure,so an assessment of the juvenile ratio(i.e.first winter birds as a proportion of total number aged)of overwintering waterbirds can be an important indicator of the reproductive success in the preceding breeding season.Methods:During 2016-2019,we sampled juvenile ratios among 10 key waterbird species from the wetlands in the YRF.Based on these data,we here attempt to establish a simple,efficient,focused and reliable juvenile ratio monitoring scheme,to assess consistently and accurately relative annual breeding success and its contribution to the age structure among these waterbird species.Results:We compared juvenile ratio data collected throughout the winter and found that the optimal time for undertaking these samples was in the early stages of arrival for migratory waterbirds reaching their wintering area(early to mid-December).We recommend counting consistently at key points(i.e.those where>1%biogeographical flyway population were counted)at sites of major flyway importance(Poyang Lake,East Dongting Lake,Shengjin Lake,Caizi Lake,Longgan Lake and Chen Lake).Based on this,the error rate of the programme(155 planned points,the count of 10 waterbird species is 826-8955)is less than 5%.Conclusions:We established a juvenile ratio monitoring programme for 10 key waterbird species in the wetlands of the YRF,and discuss the feasibility and necessity of implementing such a future programme,and how to use these data in our monitoring and understanding of the population dynamics of these waterbird populations.

Chemical forms of cobalt and nickel extracted by M1,M3 and CaCl_(2)-DTPA

Mehlich 1(M1),mehlich 3(M3)and CaCl_(2)-DTPA have been used to predict the available micronutrient in soil.However,the forms of micronutrient extractable by these extractants are not known.In the present study,ten soils,collected from five provinces and the capital of China,representing a wide range of chemical and physical properties,were analyzed by sequential extraction to isolate five forms of cobalt and nickel,they are exchangeable,carbonate bound,Fe Mn oxide bound,organically bound and residual forms.The chemical forms extracted by M1,M3 and CaCl_(2)-DTPA were also investigated.The results show strong correlation between the carbonate bound or organically bound forms of Co or Ni and the amounts of extractable by any of the above three extractants.The main forms extracted by these extractants are carbonate and organically bound forms.The ranking of these three extractants for extraction of Co and Ni are M1>M3=CaCl_(2)-DTPA and M1=M3>CaCl_(2)-DTPA,respectively.

Rate constants for the reaction of hydroxyl radicals with HFC-134a

Rate constants for the reaction of hydroxyl radicals with HFC 134a (CH 2FCF 3) have been measured by the discharge flow resonance fluorescence (DF RF) technique over the temperature range 288—370 K. The derived Arrhenius equation is: k″ =(1.27±0.16)×10 -12 exp(-(1662±41)/ T )cm 3/(mol·s). The tropospheric lifetime of HFC 134a is estimated to be 10.5 years, which is in excellent agreement with the most recent results.

Utilization of human excrement in pre-modern China,its theoretical interpretations and ecological significance

The use of human excrement as fertilizer is a characteristic of traditional Chinese agriculture..The application of excrement from urban residents in agriculture since the Song Dynasty has ensured the cleanliness and hygiene of ancientChinesecities.As early as the Ming Dynasty,the Chinese people defined the principle of fertilizing fields with human excrement from the perspective of materialcirculation.The concept Peri-URban ecosystems(PURE)provides inspiration forurban-rural symbiosis regarding circulareconomy.The use of human excrement in fertilization is a major attribute differentiating the Chinese traditional agriculture from the agriculture in other regions around the world.Despite the fact that the exact record showing that human excrement was used as fertilizer in China emerged in the Western Han Dynasty(B.C.202-A.D.8),such records did not become prevalent until the Southern Song Dynasty(A.D.1127-1279).In the Ming and Qing eras(A.D.1368-1912),human excrement was even considered"top-class fertilizerand servedas themost essential fertilizerin farmland fertilization.The importance of human excrement in the Ming and Qing was mainly reflected by farmers'purchase of human excrement from urban areas.As fertilization practices became increasingly popular during the period,men of letters built a localized theoretical system centering on human excrement.Although the use of human excrement had both positive and negative impacts on public health and the ecological environment,the positive overshadowed the negativeas a whole.Today,it is worth pondering on how the utilization of human excrement as an agricultural resource can be improved so that a material cycle system can be rebuilt to re-connect the urban and rural areas.

Degradation induces changes in the soil C:N:P stoichiometry of alpine steppe on the Tibetan Plateau

Due to the Tibetan Plateau’s unique high altitude and low temperature climate conditions,the region’s alpine steppe ecosystem is highly fragile and is suffering from severe degradation under the stress of increasing population,overgrazing,and climate change.The soil stoichiometry,a crucial part of ecological stoichiometry,provides a fundamental approach for understanding ecosystem processes by examining the relative proportions and balance of the three elements.Understanding the impact of degradation on the soil stoichiometry is vital for conservation and management in the alpine steppe on the Tibetan Plateau.This study aims to examine the response of soil stoichiometry to degradation and explore the underlying biotic and abiotic mechanisms in the alpine steppe.We conducted a field survey in a sequent degraded alpine steppe with seven levels inNorthern Tibet.The plant species,aboveground biomass,and physical and chemical soil properties such as the moisture content,temperature,pH,compactness,total carbon(C),total nitrogen(N),and total phosphorus(P)were measured and recorded.The results showed that the contents of soil C/N,C/P,and N/P consistently decreased along intensifying degradation gradients.Using regression analysis and a structural equation model(SEM),we found that the C/N,C/P,and N/P ratios were positively affected by the soil compactness,soil moisture content and species richness of graminoids but negatively affected by soil pH and the proportion of aboveground biomass of forbs.The soil temperature had a negative effect on the C/N ratio but showed positive effect on the C/P and N/P ratios.The current study shows that degradation-induced changes in abiotic and biotic conditions such as soil warming and drying,which accelerated the soil organic carbon mineralization,as well as the increase in the proportion of forbs,whichwere difficult to decompose and input less organic carbon into soil,resulted in the decreases in soil C/N,C/P,and N/P contents to a great extent.Our results provide a sound basis for sustainable conservation and management of the alpine steppe.

Size matters: wintering ducks stay longer and use fewer habitats on largest Chinese lakes

Background:Evidence suggests that wintering waterbirds have become conspicuously more concentrated at two largest lakes of the Yangtze River Floodplain,East Dong Ting Lake(Hunan Province,29°20′N,113°E)and Poyang Lake(Jiangxi Province,29°N,116°20′E),relative to other lakes,despite the establishment of reserves elsewhere.While this relationship is likely due to greater extent of undisturbed habitats in larger lakes,we understand little of the drivers affecting individual behaviours behind this tendency.Methods:We tracked wintering movements of three duck species(Eurasian Wigeon Mareca penelope,Falcated Duck M.falcata and Northern Pintail Anas acuta)using GPS transmitters,examining differences between the two largest lakes and other smaller lakes in ducks’habitat use,duration of stay at each lake and the daily distances moved by the tagged birds while at these sites.Results:The Eurasian Wigeon and Falcated Duck stayed five times longer and almost exclusively used natural habitat types at the two large lakes(91‒95%of positions)compared to length of stay time at smaller lakes,where they spent 28‒33 days on average(excluding the capture site)and exploited many more different habitats(including c.50%outside lakes).Conclusions:Our study is the first to show that shorter length of stay and more varied habitat use by ducks at small lakes may contribute to explaining the apparent regional concentration of numbers present of these and other species at the largest lakes in recent years.This compares with their declining abundance at smaller lakes,where habitat loss and degradation has been more manifest than on the larger lakes.

Effect of land-use and land-cover change on nutrients in soil in Bashang area,China

The Bashang area is a water source area and ecological barrier zone for Beijing and Tianjin. The area is located at 200 km from Beijing and Tianjin and is a typical agriculture pasture interlacing zone, in which the eco environment is vulnerable and hence it is sensitive to environmental change. The area is relatively lagged in social and economic development, where the traditional cultivation mode is predominated in agriculture and animal husbandry, but the disturbance by human activity is relatively small. Therefore, in order to reveal the interrelation between eco environmental change in the area and environmental change in Beijing and Tianjin area, it is fairly necessary to study the effect of land use and land cover change on nutrients in soil in this area. According to the actual situation of changed land use for the limited time period, five series of changed land plots were selected and 4 samples were collected from each series for the study. The samples were collected from different soil forming levels at the same site in different time. Analysis of the collected samples indicates that in the process of change of land use and land cover, the nutrients in soil, such as organic matter, total N, total P, total K, and available N, P, K, and B, Mo, Mn, Zn, Cu, and Fe, have regularly changed. When the land had changed from grassland and non irrigated farmland into woodland, and from non irrigated farmland into irrigated field, the nutrients in soil totally increased. But there exists some exception, i.e. quick acting N, P, K, and some microelements have appeared to be inconsistent with the mentioned above regularity in some cases.

Preparation of ultrahigh-surface-area sludge biopolymers-based carbon using alkali treatment for organic matters recovery coupled to catalytic pyrolysis

In this work,we employed waste activated sludge(WAS)as carbon source to prepare ultrahigh specific surface area(SSA)biopolymers-based carbons(BBCs)through alkali(KOH)treatment coupled to pyrolysis strategy.Before the pyrolysis process,the involvement of KOH made a great recovery of soluble biopolymers from WAS,resulting in highly-efficient catalytic pyrolysis.The Brunner-Emmett-Teller and pore volume of BBCs prepared at 800℃(BBC800)reached the maximum at 2633.89 m2·g-1 and 2.919 m3·g-1,respectively.X-ray photoelectron spectroscopy suggested that aromatic carbon in the form of C=C was the dominant fraction of C element in BBCs.The N element in BBCs were composed of pyrrolic nitrogen and pyridinic nitrogen at 700℃,while a new graphitic nitrogen appeared over 800℃.As a refractory pollutant of wastewater treatment plants,tetracycline(TC)was selected to evaluate adsorption performance of BBCs.The adsorption behavior of BBCs towards TC was conformed to the pseudo-second-order kinetic and the Langmuir models,signifying that chemisorption of monolayers was dominant in TC adsorption.The adsorption capacity of BBC800 reached the maximum at 877.19 mg·g-1 for 90 min at 298 K.Thermodynamic analysis indicated that the adsorption process was endothermic and spontaneous.Hydrogen bonding andπ-πstacking interaction were mainly responsible for TC adsorption,and interfacial diffusion was the main rate-control step in adsorption process.The presence of sol-uble microbial products(SMPs)enhanced TC removal.This work provided a novel strategy to prepare bio-carbon with ultrahigh SSA using WAS for highly-efficient removal of organic pollutants.

Cyclical helping hands: seasonal tailwinds differentially affect migrating Oriental Storks (Ciconia boyciana) travel speed

Background:The Oriental Stork(Ciconia boyciana)breeds in southeastern Siberia and parts of northeast China,and winters mainly in southeast China.Although the autumn migration pattern of Oriental Storks has been previ-ously described,differences between spring and autumn migration travel speed in relation to wind assistance were unknown.Methods:Using GPS/GSM transmitters,we tracked the full migrations of 18 Oriental Storks during 2015-2018 to compare differences in autumn and spring migration patterns,and combined the satellite telemetry data with the National Center for Environmental Prediction Reanalysis data to explain the relationship between 850 mbar wind vec-tors and seasonal differences in travel speed.Results:Differences in tailwinds contributed to significant differences in daily average Oriental Storks travel speed in spring(258.11±64.8 km/day)compared to autumn(172.23±49.7 km/day,p<0.001).Storks stopped significantly more often in autumn than spring(1.78±1.1 versus 1.06±0.9,p<0.05),but stopover duration(15.52±12.4 versus 16.30±15.1 days,respectively,p=0.3)did not differ significantly.Tailwinds at 850 mbar pressure level(extracted from the National Center of Environmental Prediction Reanalysis data archive)significantly affected daily flying speed dur-ing spring and autumn migration.Tailwind conditions in spring(mean 4.40±5.6 m/s)were always more favourable than in autumn when they received no net benefit(0.48±5.6 m/s,p<0.001).Despite mean spring migration dura-tion being less than autumn(27.52±15.9 versus 32.77±13.4 days,p=0.17),large individual variation meant that this duration did not differ significantly from each other.Conclusions:For long distance migratory soaring birds(such as storks),relative duration of spring and autumn migration likely relates to the interaction between imperative for earliest arrival to breeding grounds and seasonal meteorological conditions experienced en route.

Distribution of atrazine in a crop-soil-groundwater system at Baiyangdian Lake area in China

In this paper, the concentration distribution and environmental fate of atrazine in a crop soil groundwater system at Baiyangdian Lake area of North China were studied. The concentration of the herbicide in spatial and vertical soils, and in roots, stem, leaf, corncob and kernel of corn, and in groundwater were measured by HPLC. The results showed that the variation of spatial concentration of atrazine in soil can be described by first order kinetics equation which has a half life of 360 days and a rate constant of 0.0019d -1 . The vertical variation of atrazine concentration with soil depth follows the exponential decay law. After 120 days following atrazine application, the mass distributions of this herbicide in crop soil groundwater system are 71% in soil, 20% in groundwater and 1% in crop respectively, and 8% due to loss by degradation or often removal processes. The order of atrazine concentration in every part of corn crop is in roots>in corncob>in kernel of corn>in leaf.

Optimization of experimental conditions in studies on metabolism of 4-nitrobiphenyl

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Dynamic simulation and modeling of PCP transport between sediment and water

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Control effects of pε and pH on the generation and stability of chlorine dioxide

A new method, without assistance of activity ratio diagram, was applied to construct the p ε \|pH diagrams for chlorine system. The optimal pH range for generation of ClO_(2) by contacting Cl 2(g) directly with ClO^(-) _(2) solution is within pH 1.35-1.94, particularly within pH 1 35-4 00 only if minimizing the formation of Cl_(2) It is unachievable to synthesize pure ClO_(2) from the reaction of Cl_(2) and ClO^(-)_(2). Conversely, ClO_(2) may be present a variation of stability in different waters owing to the changed p ε and pH. ClO_(2) could be relatively stable if not disproportionate into ClO^(-)_(3), coexisting with ClO^(-) _(2) (p ε 17 63 and pH>9 68), Cl_(2) (pH≤0.92) or Cl^(-)(pH 0.92-9.68). When chlorine system has already reached the ultimate equilibria, ClO_(2) is a stable species in strongly acid media. As the acidity decreases, ClO 2 disproportionates into ClO^(-)_(3) and Cl_(2) Aqueous ClO_(2) is unstable within the normal pH range. This work initially, theoretically elucidates the generation and stability of ClO_(2) by way of the p ε pH diagrams.

Integrated assessment of urban environment in China

The principles and procedures for integrated environmental assessment(IEA) based on the specific urban conditions and Chinese characteristics have been developed. The development processes and the general principles and procedures are presented in this paper. Indicators and methods for IEA may vary from case to case, but guidelines for selection of indicators and methods may be applicable for a specific case, so they are also introduced. Although great progress has been made in IEA, there is still a lot for future development. Prospects are presented as follows: (1) IEA at strategic level; (2) mechanisms for public involvement; (3) post project analysis; (4) cumulative impact assessment; and (5) application of new approaches such as expert system and GIS in IEA.

Assay of some volatile compounds in human exhalation

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Mercury consumption and contamination of environment in gold mining in China

Amalgamation (sluice methods) used in the extraction of golds from ores and concentrates causes mercury contamination of the environment, which is increasingly concerned in China. The mercury specific consumption in the technical procedures has been evaluated based on the investigation of 33 mines. The average consumption of Hg is 14.6 g/ton raw ores, the ratio of Hg to gold is 6.35 g(Hg)/g(Au), total consumption of Hg in 1995 was 80 tons. The mercury amount entering into environment was 20 tons/a. Up to now 13.26% total gold produced in China is still using amalgamation, although prohibition of amalgamation since 1985 was officially proclaimed. At present, the amalgamation usage tendds to go up in some companies becasue of the benefic promotion. The irreversible mercury consumption was dispersed in the air(50%), tailing (23%) and partly(27%) entered into the downward products in the production, such as ore concentrates which was refined in the plants and caused pollution of environment near the smelter.

Arrayed Cobalt Phosphide Electrocatalyst Achieves Low Energy Consumption and Persistent H2 Liberation from Anodic Chemical Conversion

Electrochemical reduction of water to hydrogen(H2) offers a promising strategy for production of clean energy,but the design and optimization of electrochemical apparatus present challenges in terms of H2 recovery and energy consumption.Using cobalt phosphide nanoarrays(Co2 P/CoP NAs) as a charge mediator,we effectively separated the H2 and O2 evolution of alkaline water electrolysis in time,thereby achieving a membrane-free pathway for H2 purification.The hierarchical array structure and synergistic optimization of the electronic configuration of metallic Co2 P and metalloid CoP make the Co2 P/CoP NAs high-efficiency bifunctional electrocatalysts for both charge storage and hydrogen evolution.Theoretical investigations revealed that the introduction of Co2 P into CoP leads to a moderate hydrogen adsorption free energy and low water dissociation barrier,which are beneficial for boosting HER activity.Meanwhile,Co2 P/CoP NAs with high capacitance could maintain a cathodic H2 evolution time of 1500 s at 10 mA cm^(-2) driven by a low average voltage of 1.38 V.Alternatively,the energy stored in the mediator could be exhausted via coupling with the anodic oxidation of ammonia,whereby only 0.21 V was required to hold the current for 1188 s.This membrane-free architecture demonstrates the potential for developing hydrogen purification technology at low cost.

Sustainable urban systems:from landscape to ecological processes

Our world is experiencing unprecedented land cover and land use changes(LCLUC)due to population growth,economic development,and global climate change.Urbanization,one major form of LCLUC,has received growing attention for its significant role in changing ecological processes and functions of urban landscapes.There is a growing need,from both the academic and the policy-making communities,for science-based information and evidence to enhance our understanding of the urban ecological processes and societal needs because of the rapid urbanization over the past few decades across the world.Such information is key to informing the development of best practices for improved landscape and urban planning.

Study of Tea Digitized Chromatographic Fingerprint Spectra Using Micellar Electrokinetic Chromatography

This paper described the principle of digitized chromatographic fingerprint spectrum and established digitized chromatographic fingerprint spectra of ten brands of Chinese famous tea by the micellar electrokinetic chromatography. This work was done using a 25 mmol·L -1 sodium dodecylsulfate in a 20 mmol·L -1 borate (pH 7 0) solution as running buffer, 20 kV applied potential and detection at 280 nm. The chromatographic fingerprint spectra were digitized by the relative retention value ( α ) and the relative area ( S r), and were analyzed to identify the tea samples. In the absence of the standard samples, the present method was easy setup and inexpensive, and provided the applicable information for the quality assessment of teas.