Co-treatment of landfill leachate and municipal wastewater using the ZELIAC/zeolite constructed wetland system.

Constructed wetland (CW) is a low-cost alternative technology to treat wastewater. This study was conducted to co-treat landfill leachate and municipal wastewater by using a CW system. Typha domingensis was transplanted to CW, which contains two substrate layers of adsorbents, namely, ZELIAC and zeolite. Response surface methodology and central composite design have been utilized to analyze experimental data. Contact time (h) and leachate-to-wastewater mixing ratio (%; v/v) were considered as independent variables. Colour, COD, ammonia, nickel, and cadmium contents were used as dependent variables. At optimum contact time (50.2 h) and leachate-to-wastewater mixing ratio (20.0%), removal efficiencies of colour, COD, ammonia, nickel, and cadmium contents were 90.3%, 86.7%, 99.2%, 86.0%, and 87.1%, respectively. The accumulation of Ni and Cd in the roots and shoots of T. domingensis was also monitored. Translocation factor (TF) was >1 in several runs; thus, Typha is classified as a hyper-accumulator plant.

Martial recycling from renewable landfill and associated risks: A review.

Landfill is the dominant disposal choice for the non-classified waste, which results in the stockpile of materials after a long term stabilization process. A novel landfill, namely renewable landfill (RL), is developed and applied as a strategy to recycle the residual materials and reuse the land occupation, aim to reduce the inherent problems of large land occupied, materials wasted and long-term pollutants released in the conventional landfill. The principle means of RL is to accelerate the waste biodegradation process in the initial period, recover the various material resources disposal and extend the landfill volume for waste re-landfilling after waste stabilized. The residual material available and risk assessment, the methodology of landfill excavation, the potential utilization routes for different materials, and the reclamation options for the unsanitary landfill are proposed, and the integrated beneficial impacts are identified finally from the economic, social and environmental perspectives. RL could be draw as the future reservoirs for resource extraction.

Application of hydration reaction on the removal of recalcitrant contaminants in leachate after biological treatment.

Leachate contains amounts of non-biodegradable matters with COD range of 400-1500mg/L after the biological treatment, and should be removed further to attain the Chinese discharge standards. Hydration reaction has the potential to combine and solidify some recalcitrant substances, and thus could be applied as the advanced leachate treatment process. It was found that COD and NH3N decreased from 485 to<250mg/L and 91 to 10mg/L, with the removal rate over 50% and 90% in the first 6d, respectively, and COD and NH3N removal capacity were around 23.7 and 9.2mg/g under the test conditions. The percentage of the substances with low Mn range of<1000 decreased from 32.9% to 3.2% in leachate after hydration reaction. Tricalcium aluminate, tricalcium silicate and dicalcium silicate were the most activity compounds successively for the pollutant removal in leachate, and hydration reaction could be the option for the advanced wastewater treatment process thereafter.

Rapid identification of chemical components in Artemisiae argyi folium by RRLC-TOFMS / 药学实践杂志

Objective To identify the chemical components in Artemisiae argyi folium by rapid resolution liquid chromatog-raphy-time of flight mass spectrometry (RRLC-TOFMS).Methods The separation was performed on an Agilent Eclipse C18 column (2.1 mm ×100 mm,1.8 μm ).The mobile phase consisted of acetonitrile (A) and 0.1% formic acid (B) were in gradient elu-tion.The flowing rate was 0.35 ml/min, the injection volume was 1μl and the temperature of column was 40℃.Time of flight mass spectrometer ( TOFMS) with electro spray ion source ( ESI) was applied to qualitative analysis under the positive ion mode, and mass scan range was m/z 100-1 500 .Results 31 chemical compounds in Artemisiae argyi folium were identified unequivocally .Conclu-sion A rapid and efficient RRLC-TOFMS approach for identifying the chemical constituents of Artemisiae argyi folium had been suc-cessfully established,which paved a way for quality control and further in vivo studies of Artemisiae argyi folium.

Overview of the research on drug impurity / 药学实践杂志

As special commodities , drugs had closely relationships with human beings′health and life safety .Impurity, which would influence the stability and efficacy of drugs , was closely related to the quality , safety and efficacy of drugs .With more and more attendance had been attached to the impurity′s control in the development of drugs , researchers turned their attentions to the analysis of trace impurity .In this paper , related progresses in recent 10 years were summarized , including guiding principles in impurity re-search, technologies in qualitative research and general approaches in quantitative research .

Source reduction of the landfill leachate strength in a functional layer embedded landfill (FLEL).

In order to reduce the leachate strength from landfill at source, a novel landfill, functional layer embedded landfill, was developed through the introduction of the functional layers, and a comparative study was conducted between the functional layer embedded landfill (FLEL, R1) and the conventional landfill (CL, R2). It was found that the pollutant in leachate effluent from R1 was 20-50%, 14-43% and 33-75% of that from R2, in terms of COD, TN and NH(3)-N. The cumulative movement of waste settlement was about 16.4 and 13.1cm in R1 and R2 under the test period of 1 years, resulting in 13.7% and 10.9% of the original landfill height. Therefore, FLEL could save the land area and the cost of the leachate treatment process due to the reduction of leachate strength, and more waste could be disposed in landfill through the acceleration of the MSW degradation process, comparing to the CL.

Comparative analysis of essential oils found in Rhizomes Curcumae and Radix Curcumae by gas chromatography-mass spectrometry / 药物分析学报

A comparison of the volatile compounds in Rhizomes Curcumae (Ezhu) and Radix Curcumae (Yujin) was undertaken using gas chromatography-mass spectrometry (GC-MS).Ultrasonic extraction and GC-MS methods were developed for the simultaneous determination of five sesquiterpenes,namely,α-pinene,β-elemene,curcumol,germacrone and curdione,in Ezhu and Yunjin.Good linearity (r＞0.999) and high inter-day precision were observed over the investigated concentration ranges.The validated method was successfully used for the simultaneous determination of five sesquiterpenes in Ezhu and Yujin.The quantitative method can be effectively used to evaluate and monitor the quality of Chinese curcuma in clinical use.

Comparative analysis of essential oils found in Rhizomes Curcumae and Radix Curcumae by gas chromatography-mass spectrometry / 药物分析学报

A comparison of the volatile compounds in Rhizomes Curcumae （Ezhu） and Radix Curcumae （Yujin） was undertaken using gas chromatography mass spectrometi-y （GC-MS）. Ultrasonic extraction and GC-MS methods were developed for the simultaneous determination of five sesquiterpenes, namely, α-pinene, β-elemene, curcumol, germacrone and curdione, in Ezhu and Yunjin. Good linearity （r〉0.999） and high inter-day precision were observed over the investigated concentration ranges. The validated method was successfully used for the simultaneous determination of five sesquiterpenes in Ezhu and Yujin. The quantitative method can be effectively used to evaluate and monitor the quality of Chinese curcuma in clinical use.

Characteristics of environmental factors and their effects on CH4 and CO2 emissions from a closed landfill: an ecological case study of Shanghai.

To elucidate the influence of landfill gas (LFG) emission on environmental factors, an ecological investigation that was primarily concerned with the characteristics of vegetation, cover soil, and solid waste in the landfill was carried out. Temporal and spatial variations in vegetation diversity and coverage and their effects on reducing the emission of methane in the landfill were investigated. The results showed that both vegetation coverage and diversity increased with elapsed landfill closure time. The transition trend of the vegetation species was from perennial plant (Phragmites australis) to annual plants. Perennial vegetation was the dominant type of vegetation during the early closure period, and annual vegetation coverage increased with closure time. Vegetation preferentially appeared in areas of comparatively high depth of cover soil, which was characterized by high moisture retentiveness that enabled vegetation growth. The concentrations of methane and carbon dioxide in the cover soil significantly decreased with increasing closure time. The concentrations of methane and carbon dioxide from bare cover soil were higher than those from vegetated cover soil whereas the CO(2) flux of bare cover soil was less than that of vegetated cover soil.

From diagnosis to treatment: the research progresses of quantum dots in biomedicine / 国际生物医学工程杂志

Quantum Dots (QDs) with its unique optical properties including broad-range excitation, sizetunable narrow emission spectra and the adjustable emission wavelength by changing the size of core composition, is widely applied in biomedicine as a fluorescent marker in recent years. This paper focuses on the review of the characteristic of ODs, the prospects of its applications in biological and medical areas and the latest research development.Moreover,key issues including the potential toxicity of ODs are discussed.

Rapid analysis of components in Rhizoma Anemarrhenae by HPLC-DAD-MS and HPLC-DAD-TOFMS / 药物分析学报

A global quality control method based on high performance liquid chromatography (HPLC) coupled with diode array detection (DAD), single quadrupole mass spectrometry (MS) and time-of-flight mass spectrometry (TOFMS) was developed for simultaneous determination of seven major components (mangiferin, neomangiferin, timosaponin E1, timosaponin E, timosaponin BⅡ, timosaponin BⅢ, and timosaponin AⅢ) and identification of most components in extracts of Rhizoma Anemarrhenae (RA). HPLC analysis was performed on an Agilent SB-C18 column (4.6 mm×150 mm, 5 μm) by gradient elution using acetonitrile and water-acetic acid(100∶0.05, v/v) as the mobile phase. Seven major components in RA were successfully separated. This quantitative method was fully validated in respect of the following performance criteria: linearity, precision, repeatability, stability, accuracy, limits of detection (LOD) and quantification (LOQ). A formula database of known compounds in RA was established, against which, most of the reported components in this herbal extract were identified effectively based on the extract masses acquired by TOFMS. This qualitative and quantitative method was successfully used to analyze the components in 10 batches of RA samples collected from different regions in China. This global quality control method, which consisted of HPLC-DAD-MS assay of seven major components and unambiguous identification of nineteen components, is suitable for routine quantification and comprehensive quality control of RA.

Natural attenuation and characterization of contaminants composition in landfill leachate under different disposing ages.

Chemical Oxygen Demand (COD) composition in landfill leachate would vary as the disposal time extended. Leachates with different ages were collected from Laogang Refuse Landfill of Shanghai, the largest landfill in China with a placement scale of 7600 t refuse per day. To characterize COD composition in leachate, samples were size-fractioned into suspended fractions (>0.45 microm), colloid fraction (0.45 microm

Hydrophobic organic chemicals (HOCs) removal from biologically treated landfill leachate by powder-activated carbon (PAC), granular-activated carbon (GAC) and biomimetic fat cell (BFC).

Biological pretreatment efficiently remove organic matter from landfill leachate, but further removal of refractory hydrophobic organic chemicals (HOCs) is hard even with advanced treatment. In this work, three-stage-aged refuse bioreactor (ARB) efficiently removed chemical oxygen demand (COD) and biochemical oxygen demand (BOD) of fresh leachate produced in Shanghai laogang landfill, from 8603 to 451 mg L(-1) and 1368 to 30 mg L(-1), respectively. In downstream treatment, 3 g L(-1) powder-activated carbon (PAC), granular-activated carbon (GAC) and biomimetic fat cell (BFC) removed 89.2, 73.4 and 81.1% HOCs, but only 24.6, 19.1 and 8.9% COD, respectively. Through the specific HOCs accumulation characteristics of BFC, about 11.2% HOCs with low molecular weight (<1000 Da) in the biologically treated leachate were concluded. Since HOCs are competitively trapped by dissolved organic matters (DOM), the ultimate removal of HOCs from leachate is unreachable by activated carbon or BFC. It was also found that the biologically treated leachate effluent exhibited a wide molecular weight distribution (34-514,646 Da). These constitutes are derived from both autochthonous and allochthonous matters as well as biological activities.

Size-fractionation and characterization of refuse landfill leachate by sequential filtration using membranes with varied porosity.

Fresh leachate and effluents samples were collected from the holding tank, anaerobic, anoxic, and aerobic lagoons at Shanghai Laogang Refuse Landfill, the largest landfill in China with a placement scale of 9000 t refuse per day. To characterize the difference in leachate along the treatment processes, especially the information about size distribution of colloids in those leachate, the organic matters were size-fractioned into suspended particles (SP, >1.2 microm), coarse colloids (CC, 1.2-0.45 microm), fine colloids (FC, 0.45 microm to 1 kDa MW, 1 Da=1/16 O atomic mass unit), and dissolved organic matters (DM, <1 kDa MW) using micro-filtration and ultra-filtration membranes in order. The parameters, such as COD (chemical oxygen demand), TOC (total organic carbon), TS (total solid), pH, TP (total phosphate), TN (total nitrogen), FS (fixed solid), NH4+, IC (inorganic carbon), TC (total carbon), color, turbidity and conductivity in the filtrates resulting from sequential filtration of leachate, were then determined, and quantitative relationships between these parameters and the membrane molecular sizes used were established. Typically, the total removal of COD, NH4+, conductivity and P were found to be 75%, 75%, 42% and 85%, respectively, after the biological treatment processes used at Laogang Refuse Landfill. Dissolved fractions were predominant in fresh leachate and in effluents from treatment processes in terms of TOC with a content of over 47%. The molecular weight (MW) percentage distribution in leachate varied as the leachate was treated in the biological treatment stages. The percentages of TOC of fine colloid fractions increased from 6% to 38% while those of dissolved fractions decreased from 78% to 47%. TN in leachate also predominated in the dissolved fraction, occupying over 58%, while those TP in leachate were combined with the SS and CC fractions. The ratios of ortho-phosphate/TP and NH4+/TN in leachate and effluents were over 50% and 80%, respectively.

Ultrasonic condition for extraction of flavone from Radix Astragali by orthogonal design / 第二军医大学学报

Objective:To ascertain the optimized ultrasonic condition for extraction of flavone from Radix Astragali by orthogonal design. Methods: The contents of calycosin-7-O-?-D -glucoside and formononetin were taken as the indices and were determined. The ultrasonic time (10 min, 20 min, and 30 min), concentrations of methanol (50%, 75% and 100%) and times of extraction (1, 2, and 3) were analyzed by orthogonal design; the best ultrasonic condition was ascertained and compared with those of soak extraction and Soxhlet extraction. Results: Ultrasonic with 100% methanol twice (20 minutes each time) was the optimized condition for extraction of flavone from Radix Astragali. The efficiency of ultrasonic extraction was better than those of soak extraction and Soxhlet extraction. Conclusion: Compared with other methods, the ultrasonic extraction of flavone from Radix Astragali is efficient, quick and simple.

Determination of loureirin A and B in home-made resina draconis by RP-high-pressure liquid chromato- graphy / 第二军医大学学报

Objective: To determine loureirin A and B in different brands of home made resina draconis,providing basis for new quality control method.Methods: A high pressure liquid chromatography(HPLC) method has been developed. UV detector wavelength was set at 270 nm.The mobile phase was acetonitrile acetic acid solution (40∶60).The flow rate was 1.0 ml/min and the column was at room temperature.Results: A good linear correlation was found in the range of 4 to 24 ?g/ml of loureirin A.The regression equation obtained was Y =855.8+803 7.1 X ( r =0.999 9); A good linear correlation was found in the range of 20 to 120 ?g/ml of loureirin B.The regression equation obtained was Y =219.3+808 1.8 X ( r =0.999 9).Conclusion: The quantities of loureirin B in all brands are lower than the limit of quality standard.The quantities of loureirin A are higher than that of loureirin B in the same sample.