Red Earth Research Articles

Activation of peroxydisulfate by nanoscale zero-valent iron for sulfamethoxazole removal in agricultural soil: Effect, mechanism and ecotoxicity

In this study, peroxydisulfate (PDS) was successfully activated by nanoscale zero-valent iron (nZVI) for the degradation of sulfamethoxazole (SMX, antibiotic frequently detected in the environment) in agricultural soils. The results indicated that the degradation of SMX was affected by the nZVI dose, the ratio of SMX/PDS, the ratio of soil/water and reaction temperature, and in cinnamon soils 87.6% of SMX degradation can be achieved within 4 h at 30 °C when the initial nZVI dose was 0.03 g g−1 soil, the molar ratio of SMX/PDS = 1/75 and the soil/water = 1/1. The results of radical scavenger experiments and electron spin resonance (ESR) tests showed that hydroxyl radical (OH) was the dominant reactive species in this system. The ecotoxicity tests of the soil by germination test, luminescent bacteria experiment and enzyme activity test indicated that the ecotoxicity of soil after treatment was obviously lower than the contaminated soil. In addition, there was almost no effect on plant growth when compared with original soil. Furthermore, this system exhibited a great degradation capacity for SMX in different types of agricultural soils, and the degradation efficiencies of SMX in other four soils were 90.6% (yellow brown earths), 80.8% (brown earths), 86.5% (black soils) and 96.1% (red earths), respectively. This work provides an optional method for agricultural soil pollution control.

First Analytical Study on Second-Century Wall Paintings from Ulpia Traiana Sarmizegetusa: Insights on the Materials and Painting Technique

ABSTRACTThis article reports the first analytical study carried on some of the oldest surviving examples of Roman wall paintings, discovered so far on the Romanian territory. Dating back to the second century, these decorative polychrome wall painting fragments were found during an archaeological research carried at Ulpia Traiana Sarmizegetusa, and represent the first mural paintings ever found on site. A set of samples was analyzed using various non-destructive and micro-invasive techniques in order to investigate the material composition and explore the painting technique. The employed methodology allowed for an in-depth characterization of the color palette, generally based on mineral pigments such as red earth, celadonite, yellow ochre, calcite, and strontianite. The absence of organic binders and the possibility to differentiate specific spectral features infer the use of a fresco-secco technique. The results obtained provide important data regarding the artistic and technological skill of ancient painters in this part of the Roman Empire, and they significantly contribute to the research and conservation work carried out at this impressive archaeological site.

Landslides-oriented urban disaster resilience assessment—A case study in ShenZhen, China

With the increasing expansion of cities associated with rapid urbanization, the ecological environment is being severely damaged, exposing cities to frequent extreme weather events. Urban ecological ecosystems are under great threat. Research on urban disaster resilience is conducive to a better understanding of disaster prevention and mitigation capacity, and provides valuable references for resilient city construction. In this study, a typical city under rapid urbanization in China – Shenzhen – was chosen as the research area, including the city's 57 sub-districts. Urban disaster resilience to rainfall-induced landslides was conceptually framed into the dimensions of physical resilience and social resilience. Support vector machine (SVM) was applied to evaluate the physical resilience and a Delphi-analytic hierarchy process (Delphi-AHP) model was used to assess social resilience on a sub-district scale in 2016. The results show that the physical resilience and social resilience of Shenzhen demonstrate obvious spatial concentration trends. Areas with low physical resilience were located in sub-districts of Dapeng New District with intense rainfall and complex topography, as well as those in Guangming New District with lateritic red earth derived from arenaceous shale. Areas with low social resilience were mainly located in eastern Shenzhen, including sub-districts in Longgang District and Dapeng New District, with undeveloped economy, inadequate infrastructures and many vulnerable people. All sub-districts in the three districts of Pingshan New District, Dapeng New District and Guangming New District need attention because of their low comprehensive resilience. Comparison of the physical resilience and social resilience indicated that the performance of physical resilience was significantly better than that of social resilience; only 26% of the sub-districts of Shenzhen had a higher level of social resilience than of physical resilience. Therefore, the government should strengthen urban management of social services and physical infrastructure provision to improve social resilience to cope with urban disasters.

OBSERVATION AND REFLECTION OF THE COUNTRY PARK— NANCHANG RED EARTH HERITAGE PARK

Located in the suburb of Nanchang City in Jiangxi Province, the Nanchang Red Earth Heritage Park is positioned as a country park that features vast vermicular red earth and Pinus massoniana forest. The off-site review and on-site exploration suggested that the site was confronting with problems of severer soil erosion, biodiversity loss, and intensive human intervention. Both to preserve the symbolic red earth in the site and to reduce cost due to limited budget, a country park requiring low intervention and maintenance was proposed. The park would also engage citizens with geological and scientific education programs and create diverse interactive experience. The design strategies were optimized through continuous site observation and reflection, both with historical and existing data in a broader sense and individual feeling by on-site exploration. This way of dialogue and connection to the site finally gives birth to a natural country park that stays in harmony with nature.

There Are Always Two Deaths

There Are Always Two Deaths Pia Ghosh-Roy (bio) The retirement home was built by a group of Bengali doctors from London and Surrey who ran the South London Tagore Society. They sang Tagore’s songs, enacted his plays, and created a cooperative to build a cluster of cottages in India a few miles from Tagore’s summer house in Shantiniketan. It was a gated development, secure and landscaped, the cottages fitted with western comforts, each with its own patch of garden, a terra-cotta water feature gurgling on the side. This is where they would live—the doctors and their spouses—once their children were grown up and settled in the West. They’d go back to India, spend their retired life in better weather and the company of like-minded people, die in the country where they’d been born. A sound plan. Only none of them returned. Except Ma. Ma who had always kept a polite distance from the Tagoreans, said their songs put her to sleep, yet had signed into their cooperative. At the time, it had seemed to me like a whim, she was gifting herself a holiday cottage to escape the winters for a few weeks. I should’ve known better. After she retired from cardiothoracic surgery, she spent a year wrapping up her life in London, sold the house, and moved to Shantiniketan on her seventieth birthday. Put an ocean between us. ________ For the first few years, her days there were full. She wrote to me of the red earth of her new home, the dusty country roads that led her out of the city, winding past rice paddies to villages where Bauls sang their songs. She translated for me the words of these traveling minstrels, songs filled with questions and a wild sense of freedom. She appointed a rickshaw-wala named Hori to take her to the library on Tuesdays. She spent mornings chatting with Bashob, the maali, who filled her garden with orange marigolds and white dahlias. She enjoyed lengthy debates with the “bright young students” who came from the university [End Page 183] to read to the older residents. She visited Adivasi villages where she wrote prescriptions for medicines and taught the English alphabet to little children. “How could you let your mother move so far away from you?” some of her friends asked me. Their question made me smile. They didn’t know her at all. She was no one’s woman except her own. That is what I loved most about her, admired most about her. It was also what I resented most about her, when she left and I couldn’t make her stay. ________ When Ma left London, I left too. But we went in opposite directions. I moved to San Francisco, accepted the job at the Asian Art Museum I’d said no to before. It had been just the two of us for so long. Us against the world. She gave us a title the day I turned thirteen. Two-Woman Team of Terrible Trail-blazers. Which became T4. Which made me cringe-smile. Life in London would have felt strange without her, so I found a way to leave. Or maybe I found a way to show her that I could get myself a new life too, all on my own. Then I wouldn’t have to be the only one listening to stories of sun and change and the smells of a different place. Now here I am, in her sun. A red-eye from San Francisco to Singapore to Kolkata, a train to Bolpur, a taxi to Shantiniketan. In time to see her turn eighty-five on Christmas Eve. I’m here every year on her birthday, but this year she doesn’t know who I am. She’d always told me that her mind would go before her body did, that it ran in her family. She tried to prepare me for it, told me what to do if it happened. But nothing truly prepares you for your parent losing their memory of the only life you’ve ever known, of watching her trying to place who you are...

Preliminary investigation of late Mughal period wall paintings from historic monuments of Begumpura, Lahore

Deterioration of wall paintings caused by environmental pollution is a worldwide problem especially with reference to the present industrial era. The alarming incremental trend of pollution in Pakistan has threatened the cultural assets. The deposition of pollutants on historic fabric is the main source of chemical and mineralogical alterations of wall paintings. The present diagnostic study investigated the main deterioration mechanisms affecting wall paintings of the late Mughal period, in the Begumpura Complex, in Lahore. Micro samples were characterized by XRD and SEM-EDS to identify deterioration products and understand deterioration mechanisms prevalent at the heritage site. The results revealed that red ocher, green earth and calcium carbonate were initially used for red, green and white pigments, respectively. Sodium chloride (halite, NaCl) and gypsum (CaSO4·2H2O) were identified as the main deterioration products.

Energy efficient production of clay bricks using industrial waste

Clay brick manufacturing is a sector which involves a lot of firing processes requiring higher temperature. To maintain this temperature, large amount of fuel in the form of wood, coal, biomass etc. need to be burnt in the kiln causing serious issues of air pollution. Also, with the increase in the number of industries coming up, large amount of un-disposable waste gets accumulated. If suitable remedies are not adopted for its safe disposal, it may pollute the water bodies through runoff. This project is an effort to reduce the brick firing temperature in the kiln to about 600 °C thereby reducing the cost of production and making the whole process environmental friendly. This work will put forward a suitable alternative for the safe disposal of industrial debris like quarry dust and glass powder by incorporating them as a partial substitute for river sand which is one of the costly constituent of clay brick and thereby further reducing the cost of production. Experimental results showed higher compressive strength of 21.31 N/mm2when the brick was casted with mix proportion of Cement: Sand: Red earth: Glass Powder: Quarry Dust = 4:1:1:1.5:2.5. The strength measured at temperature 600 °C met the requirements of the National Standards.

Formation of environmentally persistent free radicals during the transformation of anthracene in different soils: Roles of soil characteristics and ambient conditions.

Transformation of PAHs, i.e., anthracene, and production of environmentally persistent free radicals (EPFRs) on seven types of representative soils were investigated, focusing on the influences of soil characteristics and ambient conditions on these reactions. The transformation rate of anthracene exhibits the order of red earth > yellow earth > latosol ∼ fluvo-aquic soil > brown earth > chernozem > calcic brown soil, which is positively correlated with Fe content in soils. Afterwards, batch reactions on pure representatives of soil minerals, including Fe2O3, Fe3O4, FeOOH, and MnO2, demonstrate that anthracene is prone to mineral-promoted transformation. The presence of higher amount of organic carbon lower the transformation rate of anthracene, whereas the formed EPFRs can be stabilized for a longer time. Subsequent experiments associated with the influences of environmental conditions on mineral-promoted reactions suggest that both anthracene transformation and EPFRs generation readily occur under dry condition. Light irradiation not only promotes the formation of EPFRs, but also greatly accelerates the decay of EPFRs and the 1/e lifetime decreases from 5 to 20 d in dark to approximately 1 d. Meanwhile, the anoxic condition is favorable for the persistence of EPFRs. The obtained results suggested the potential environmental risks association with EPFRs in PAHs-contaminated soils.

The “Exultet 1” of Bari: multi-methodological approach for the study of a rare medieval parchment roll.

A rare medieval parchment roll, called Exultet 1 (first half of XI Century), preserved in the Diocesan Museum of Capitolo Metropolitano of Bari (Italy) has been studied. Certainly, it is one of the highest literary and artistic expressions ever produced in Bari, one of a kind. It is also the very first among medieval European liturgical rolls, in which miniatures are painted upside-down in respect to the text. To analyse inorganic pigments, a mobile laboratory has been set up at the museum. The techniques used, for a non-invasive and non-destructive in situ analysis, were: VIS-NIR spectrophotometry in reflectance mode with optic fibres (FORS), X-Ray fluorescence spectrometry (XRF) and finally µ-Raman spectroscopy. Such multi-methodological approach allowed to acquire many data without causing any stress to the artwork. The mineral pigments have been identified mainly by FORS and they are: red earth and minium, lapis lazuli and azurite, green earth and copper resinate, orpiment and yellow earth. In some areas, traces of a residual gold leaf have been identified by XRF. The presence of rare and precious pigments as lapis lazuli and gold leaf underlines the sacredness and the importance of the parchment. This is the first scientific investigation performed on the Exultet 1 of Bari.

Micro-Raman analysis of mortars and wallpaintings in the Roman villa of Fuente Alamo (Puente Genil, Spain) and identification of the application technique

This paper reports results of ongoing research on wallpaintings in the Roman villa of Fuente Alamo (Puente Genil, Southern Spain). Wall decoration vestiges from an older building stage and a newer one subsequently erected on it were examined. The lack of information about wallpaintings in this villa led us to study the materials constituting the mortars and pigments, and to elucidate the painting technique used in order to facilitate optimal restoration. Paint layers exhibited a wide variety of colours but mainly red, ochre, blue, green, black and white. Pigments included high-quality materials such as Egyptian blue and other, more common elements of the Roman palette such as red and yellow earths, and lime white. The materials were characterized by X-ray diffraction and Raman microspectroscopy.

Ceramic Water Filters: A Point-of-Use Water Treatment Technology to Remove Bacteria from Drinking Water in Longhai City, Fujian Province, China

While provision of safe drinking water is considered a basic human right, there are major challenges in the developing world for its provision. The ability to deliver safe water using a cost-appropriate technology is a major aspect of the problem. One of the technologies that has the potential to contribute significantly is the ceramic water filter (CWF); however, as shown herein, there are significant differences between performance of CWFs in the laboratory and in field applications. The CWFs employed in this study (field and laboratory) have a pore fraction of 21.0 - 22.4% and an average maximum pore diameter of 5.7 - 15.2 μm. Field studies were completed in Longhai City, China, a rural community in southeastern China with red earth, high precipitation and intensive human/ domestic activities. During field trials, CWFs demonstrated an average removal efficiency of 94.7%, with values ranging from 75 - 100%, whereas in laboratory studies, average removal efficiency was determined to be 99.5%, with values ranging from 97.7 - 99.9%. Differences between the lab and field removal efficiencies are attributed to contamination of the filter element and receptacle by villagers during field utilization and cleaning. Effective technology transfer to the end-user is required to achieve the bacterial removal efficiency attainable by the technology itself.

Analysis on metallogenic mechanism of gold ores in western guizhou province

The metallogenic mechanism of gold ores in western Guizhou Province is analysed based on previous research data. These ores have been deeply explored in previous studies, which have suggested that Emeishan Basalt and source beds arising from the basalt eruption are major provenances of gold ores in south-western Guizhou Province. The source beds form under the impacts of paleogeography of land-ocean transitional facies/lithofacies, ores with special structures and hydrothermal sedimentation. The substances exposed on the surface of the earth are enriched on quaternary red earth after weathering. The times and time of cyclic hydrothermal alteration need to be further examined.

English

English

Effects of Long-term Fertilization Regimes on As Accumulation in Upland Red Earth and the Crops Growing on It

To investigate the effects of different long-term fertilization treatments on arsenic (As) accumulation in upland red earth and the crops growing on it, different fertilization treatments, including no fertilization (CK), fertilization with chemical fertilizers containing nitrogen, phosphorus and potassium (NPK), fertilization with swine manure (M), and fertilization with chemical fertilizers plus manure (NPKM), in a long-term fertilization site located in Qiyang County, Hunan Province, were selected.. The results showed that after 26 years of fertilization, both the total and available As concentrations in the soils were significantly improved in the fertilized soils (i.e., NPK, M, and NPKM) when compared to the CK soil. Meanwhile, NPK treatment had the highest As concentration (44.68 mg·kg-1), which was higher than the national standard value (40 mg·kg-1) in acidic soils. Fertilization practices had the biggest impacts on the non-specifically-absorbed As, followed by the residual As, and the well-crystallized hydrous oxides of Fe and Al absorbed As, but minor impacts on the amorphous and poorly-crystalline hydrous oxides of Fe and Al-absorbed As, and the specifically absorbed As. Furthermore, NPKM treatment significantly decreased the concentrations of As(Ⅲ) and As(Ⅴ) in the soils, when compared to the other treatments. Also, M treatment could cause the accumulation of As in the grains and straws in corn. In contrast, M treatment could not cause the accumulation of As in the grains and straws in wheat. Furthermore, correlative synchrotron-radiation-based FTIR and micro X-ray fluorescence spectromicroscopic analysis showed that As had a similar distribution pattern with clay -OH and C-OH.

Cadmium bioavailability well assessed by DGT and factors influencing cadmium accumulation in rice grains from paddy soils of three parent materials

High Cd resulted from natural background or agricultural activities in some of the paddy soils in South China is a concern. It is imperative to understand the relationship between Cd bioavailability in high Cd soils and Cd accumulation in rice grains. Therefore, our objectives are to explore the relationship between Cd accumulation in rice grains and Cd availability which was characterized with five different methods, and to investigate factors influencing Cd accumulation in rice. One hundred and twenty-two paired soil and rice plant samples were collected from paddy fields of three parent materials (sandshale, limestone, and Quaternary red earth) in Guangxi Province. Soil Cd availability was assessed using three chemical extractants (0.43 M HNO3, 0.01 M CaCl2, and 0.005 M DTPA) and compared with Cd in soil solution and that sampled by the diffusive gradients in thin films (DGT) method. A five-step sequential fractionation of Cd was also carried out. Random forest (RF) was employed for assessing factor relative importance in Cd accumulation in rice plants and grains in high Cd soils. All of the soil samples had a total Cd content exceeding the maximum permissible concentration (0.3 mg kg−1) for soils with the exchangeable fraction taking up 50, 56, and 39%, respectively. For the rice grains harvested from the soils derived from sandshale, limestone, and Quaternary red earth, 67, 95, and 28%, respectively, had a Cd content exceeding the maximum permissible concentration for grain (0.2 mg kg−1). The results demonstrated high Cd bioavailability in these areas and indicated potential health risk when people ingest the rice grains. Cd measured by DGT best reflected Cd bioavailability. The Cd in soil solution (Cdsoln), which is directly available, and CaCl2-extracted Cd were also significantly related to grain Cd content. Factor relative importance assessment based on random forest (RF) showed that soil pH was among the top two most important physicochemical factors of the three types of soils influencing Cd accumulation in rice grains. Besides, dissolved organic carbon (DOC), clay, and dithionite-citrate-bicarbonate-extracted Mn (MnDCB) was the other major influencing factor in the sandshale soils, limestone soils, and Quaternary red earths, respectively. The results indicated that DGT technique better predicted Cd bioavailability. Manipulating soil pH could be used to reduce Cd bioavailability and its accumulation in plants. However, manipulating soil DOC, clay and Fe/Mn content were soil-type-dependent.

Fe-oxide mineralogy of the Jiujiang red earth sediments and implications for Quaternary climate change, southern China

Diffuse reflectance spectrophotometry (DRS) is a new, fast, and reliable method to characterize Fe-oxides in soils. The Fe-oxide mineralogy of the Jiujiang red earth sediments was investigated using DRS to investigate the climate evolution of southern China since the mid-Pleistocene. The DRS results show that hematite/(hematite + goethite) ratios [Hm/(Hm + Gt)] exhibit an upward decreasing trend within the Jiujiang section, suggesting a gradual climate change from warm and humid in the middle Pleistocene to cooler and drier in the late Pleistocene. Upsection trends toward higher (orthoclase + plagioclase)/quartz ratios [(Or + Pl)/Q] and magnetic susceptibility values (χlf) support this inference, which accords with global climate trends at that time. However, higher-frequency climatic subcycles observed in loess sections of northern China are not evident in the Jiujiang records, indicating a relatively lower climate sensitivity of the red earth sediments in southern China.

Peanut straw biochar increases the resistance of two Ultisols derived from different parent materials to acidification: A mechanism study

The mechanisms for increasing soil pH buffering capacity (pHBC) and soil resistance to acidification by peanut straw biochar were investigated by undertaking indoor incubation and simulated acidification experiments using two Ultisols derived from tertiary red sandstone and quaternary red earth. The biochar increased the pHBC and resistance of the two Ultisols to acidification. The addition of 3% biochar increased the pHBC of the two Ultisols by 76% and 25%, respectively. The increased resistance of the soils to acidification led to the inhibition to decrease in soil pH and the activation of soil Al during acidification. The protonation of carboxyl groups on the biochar surface was the main mechanism responsible for resisting acidification of the Ultisols when the pH was between 4.5 and 7.0. The higher soil pH (>6.0) after biochar application and the large number of carboxyl groups on the biochar surface were essential if biochar was to significantly increase the resistance of soils to acidification.

Incorporation of corn straw biochar inhibited the re-acidification of four acidic soils derived from different parent materials.

The effect of corn straw biochar on inhibiting the re-acidification of acid soils derived from different parent materials due to increased soil pH buffering capacity (pHBC) was investigated using indoor incubation and simulated acidification experiments. The incorporation of the biochar increased the pHBC of all four soils due to the increase in soil cation exchange capacity (CEC). When 5% biochar was incorporated, the pHBC was increased by 62, 27, 32, and 24% for the Ultisols derived from Tertiary red sandstone, Quaternary red earth, granite, and the Oxisol derived from basalt, respectively. Ca(OH)2 and the biochar were added to adjust the soil pH to the same values, and then HNO3 was added to acidify these amended soils. The results of this simulated acidification indicated that the decrease in soil pH induced by HNO3 was lower for the treatments with the biochar added than that of the treatments with Ca(OH)2 added. Consequently, the biochar could inhibit the re-acidification of the amended acid soils due to the increased resistance of the soils to acidification when the pH of amended soil was higher than 5.5. The inhibiting effectiveness of the biochar on soil re-acidification was greater in the Ultisol derived from Tertiary red sandstone due to its lower clay and organic matter contents and CEC than the other three soils. The incorporation of the biochar also decreased the potentially reactive Al, i.e., exchangeable Al, organically bound Al, and sorbed hydroxyl Al, compared with the treatments amended with Ca(OH)2. Therefore, the incorporation of corn straw biochar not only inhibited the re-acidification of amended acid soils through increasing their resistance to acidification but also decreased the potential of Al toxicity generated during re-acidification.

“Art Should Make You Uncomfortable”: A Conversation with Vu Tran

Author of the noir novel Dragonfish, Vu Tran teaches English and fiction at the University of Chicago. Also a contributor to the collection of essays The Displaced: Refugee Writers on Refugee Lives, Tran left Vietnam at age four and grew up in Oklahoma, graduating from the University of Tulsa then obtaining an MFA from the University of Iowa and a PhD from the University of Nevada, Las Vegas. While visiting Oklahoma City to speak to students in Oklahoma City University's Red Earth MFA program, he sat down with WLT's managing and culture editor to discuss the best teacher he ever had (spoiler alert: she was tough), his work, the role of language in dehumanizing others, and why art should make you uncomfortable.

“Art Should Make You Uncomfortable”: A Conversation with Vu Tran

Author of the noir novel Dragonfish, Vu Tran teaches English and fiction at the University of Chicago. Also a contributor to the collection of essays The Displaced: Refugee Writers on Refugee Lives, Tran left Vietnam at age four and grew up in Oklahoma, graduating from the University of Tulsa then obtaining an MFA from the University of Iowa and a PhD from the University of Nevada, Las Vegas. While visiting Oklahoma City to speak to students in Oklahoma City University's Red Earth MFA program, he sat down with WLT's managing and culture editor to discuss the best teacher he ever had (spoiler alert: she was tough), his work, the role of language in dehumanizing others, and why art should make you uncomfortable.