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1

Modeling the ecosystem response to summer coastal upwelling in the northern South China Sea

Jiang R., Wang Y.-S.

Oceanologia

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2018

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No. 60 (1)

32--51

EN

A coupled three-dimensional physical model and a nitrogen-based nutrient, phytoplankton, zooplankton, and detritus (NPZD) ecosystem model were applied to simulate the summer coastal upwelling system over the continental shelf of northern South China Sea (NSCS) and its impact on hydrographic conditions and ecosystem. The simulated results were comprehensively validated against field and satellite measurements. The model results show that the near shore ecosystem of NSCS has significant responses to the summer coastal upwelling system. The Shantou Coast to the Nanri Islands of Fujian province (YD) and the east of the Leizhou Peninsula (QD) are two main regions affected by NSCS summer coast upwelling. During summer, these two coastal areas are characterized by nearshore cold and high salinity upwelling current. Further, the summer coastal upwelling serves as a perfect nutrient pump, which lifts up and advects nutrient-rich current from deep to surface, from inner shelf to about 30 km outer shelf. This nutrient source reaches its maximum in the middle of July and then begins to decrease. However, the maximum phytoplankton and chlorophyll a do not coincide with the maximum nutrients and delay for about 10 days. Because of the intensive seasonal thermocline and the complicated current transporting through Qiongzhou strait, the ecological responding of QD is less pronounced than YD. This study has a better understanding of the physically modulated ecological responses to the NSCS summer coastal upwelling system.

2

Capillary column coated with geminal ionic liquids as stationary phases for gas chromatographic separation

Jiang R., Yang S., Luo A.

Acta Chromatographica

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2017

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Vol. 29, no. 1

25--43

EN

Four geminal ionic liquids (GILs), namely, 1,4-bis(1,1′-butyl-3,3′- methylene- imidazolium)-benzene bis[(trifluoromethyl)sulfonyl]imide (BBMIB-NTf2), 1,4- bis(1,1′-butyl-3,3′-methylene-imidazolium)-benzene tetrafluoroborate (BBMIB-BF4), 1,4- bis(1,1′-butyl-3,3′-methylene-imidazolium)-benzene hexafluophosphate (BBMIB-PF6), and 1,4-bis(1,1′-methyl-3,3′-methylene-imidazolium)-benzene bis[(trifluoromethyl) sulfonyl] imide (BMMIB-NTf2), were synthesized. They were statically coated onto the inner walls of fused-silica capillary columns and used as stationary phases for gas chromatography. The evaluation of BBMIB-NTf2, BBMIB-BF4, BBMIB-PF6, and BMMIB-NTf2 as stationary phases is reported here for the first time. These new stationary phases exhibit efficiencies of at least 2.3 × 103 plates per meter. Abraham solvation parameter model was used to evaluate the solvation characteristics. The system constants indicated that the dipolarity/polarizability and the hydrogen-bond basicity play a major role among five molecular interactions between stationary phases and solute molecules. A fundamental understanding into the solvation characteristics of these GILs can be used as a guide to choosing the appropriate geminal ionic liquids for specific applications in various fields. The chromatographic separation performance was evaluated by a Grob test mixture, n-alkanes, alcohols, and aromatic isomers. Furthermore, the thermal stability was tested. The present results demonstrate that these geminal ionic liquids stationary phases possess excellent chromatographic separation performance and good thermal stability (at least up to 270 °C) and may be applicable as gas chromatography stationary phases for more application.

3

Estimation of phosphorus recovery by struvite crystallization from animal manure wastewater in China

Fang C., Zhang T., Czechowska-Kosacka A., Pawlowski A., Łagód G., Jiang R., Wang Q.

Environment Protection Engineering

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2015

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Vol. 41, nr 4

195--207

EN

Intensive farming is main industry which produces large amount of animal manure wastewater with high content of phosphorus. Its discharging to surface water leads to eutrophication. On the other hand, phosphorus is vital for plant growth and its natural reserves are rapidly exhausted. Therefore, recovering phosphorus from animal manure wastewater can achieve two important goals: prevention of eutrophication and recovery of non-renewable phosphorus compounds. The method of struvite precipitation has been presented for phosphorus recovery from animal manure wastewater. Based on scenario study, 8.76 million tons of struvite could be produced from animal manure wastewater in China.

4

Application of struvite process for nutrient recovery from anaerobic digesters of livestock wastewater

Zhang T., Fang C., Li P., Jiang R.

Environment Protection Engineering

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2014

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Vol. 40, nr 3

29--42

EN

Process of struvite (Mg4NH4PO4·6H2O) precipitation is a promising method for phosphorus recycling. The use of cheap magnesium ore for precipitation struvite as phosphate recovery has been examined. The optimal conditions for precipitation are pH 9.0 and Mg2+: NH4 +: PO4 -3 molar ratio 1.1:30.7:1. Linear correlation of experimental data is in qualitative agreement with modelling calculation. Surface characterization analysis demonstrates that struvite is the dominant component of precipitate. Fertility value tests show that struvite precipitate could be available as slow-release fertilizer.

5

Phosphate recovery from animal manure wastewater by struvite crystallization and CO2 degasification reactor

Zhang T., Li P., Fang C., Jiang R.

Ecological Chemistry and Engineering. S

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2014

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Vol. 21, nr 1

89--99

EN

The problem of phosphorus discharge is related to environmental protection and food security. Struvite crystallization is a useful technology for phosphate recovery from wastewater. In the research, struvite crystallization process with CO2 degasification continuous U-shape reactor (CUSR) was application for phosphate recovery from animal manure wastewater. The result indicated PO43--P recovery ratio could achieve 47-53% without magnesium addition when CUSR hydraulic retention time controlled at 60 min. With extra magnesium addition, PO43--P recovery ratio could significant achieve 80-86% at magnesium addition amount 57.5 mg/dm3. PHREEQC modeling predictions trend of struvite crystallization was close to CUSR experimental results. The modeling calculation can provide a theoretical guide for operational parameters design. For seeding technology, high phosphate recovery efficiency was obtained and preformed struvite was the most effective seeding material. Surface characterization analysis demonstrated the dominant composition of chemical solids was struvite. Water extraction analysis indicated chemical solids recovery from animal manure wastewater could release PO43--P slowly and be available as slow-release fertilizer.

PL

Problem uwalniania fosforu jest związany z ochroną środowiska i bezpieczeństwem żywności. Krystalizacja struwitu jest przydatną technologią odzysku fosforanów ze ścieków. W opisanych badaniach proces krystalizacji struwitu zastosowano do odzyskiwania fosforanów z gnojowicy, do tego celu wykorzystano reaktor ciągłego odgazowywania CO2 w kształcie litery U (CUSR). Wyniki wskazują, że wskaźnik odzysku PO43- może osiągnąć 47-53% P bez dodatku magnezu, gdy kontrolowany, hydrauliczny czas retencji CUSR wynosi 60 min. Po wprowadzeniu magnezu w ilości 57,5 mg/dm3 wskaźnik odzysku PO43- może osiągnąć 80-86% P. Przewidywania modelu PHREEQC dotyczące krystalizacji struwitu był bliskie wynikom doświadczalnym CUSR. Obliczenia teoretyczne z wykorzystaniem modelu mogą stanowić wskazówkę do ustalania rzeczywistych parametrów eksploatacyjnych. Struwit otrzymany z gnojowicy może mieć zastosowanie w nasiennictwie. Analiza ekstrakcyjna wykazała, że materiał ten może powoli uwalniać PO43-P i dzięki temu znajduje zastosowanie jako nawóz.

6

Podejście nieparametryczne do modelowania przyrostu niezawodności złożonych systemów naprawialnych

Jiang R.

Eksploatacja i Niezawodność

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2009

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nr 3

78-81

PL

W złożonym systemie naprawialnym, przyczyny uszkodzeń zidentyfikowane przez program do badania przyrostu niezawodności nie zawsze są usuwalne. Duże wyzwanie stanowi ocena niezawodności systemu na podstawie obserwacji z badań oraz działań naprawczych. Niniejszy artykuł przedstawia nieparametryczną metodę oceny niezawodności systemu. Proponowane podejście uwzględnia informacje o częściowej skuteczności działań naprawczych. Wykorzystanie tych częściowych informacji pozwala na zrewidowanie obserwowanego zestawu danych oraz późniejsze włączenie ich do modelu rozkładu. Średni czas pomiędzy uszkodzeniami (MTBF) ocenia się na podstawie dopasowanego modelu. Proponowane podejście zilustrowano przykładem.

EN

For a complex repairable system, the identifi ed failure modes during a reliability growth test program are not always fi xable. It is a challenging issue to estimate the reliability of the system based on the test observations and corrective actions. This paper presents a non-parametric approach for evaluating the system reliability. The proposed approach incorporates partial information about the effectiveness of corrective actions. Using the partial information, the observed data set is revised, which is then fi tted into a distribution model. The MTBF is estimated based on the fi tted model. The proposed approach is illustrated by an example.