Specific ion effects on the soil shear strength and clay surface properties of collapsing wall in Benggang.

Benggangs are a special type of soil erosion in the hilly granite regions of the tropical and subtropical areas of Southern China. They cause severe soil and water loss, which can severely deteriorate soil quality and threat to the local ecological environment. Soils (red soil, sandy soil and detritus soil) were collected from collapsing wall of a typical Benggang in Changting County of Fujian Province, and their physicochemical and mineralogical properties were analyzed.

Impact of soil surface properties on soil swelling of different soil layers in collapsing wall of Benggang.

Benggang is one of the most serious soil erosion problems in tropical and subtropical areas in southern China. Little work has been reported on the surface properties of soil colloidal particle and its influence on soil swelling of different soil layers in collapsing wall of Benggang. In this present work, the effects of sodium concentration on soil swelling, and the correlations between soil swelling rates and soil colloidal surface properties were comprehensively evaluated by carefully examining soil physicochemical properties and soil colloidal surface properties of red, sandy and detritus soil layers from a collapsing wall.

Mechanisms for potential Pb immobilization by hydroxyapatite in a soil-rice system.

This study aimed to investigate the mechanism of lead (Pb) immobilization by hydroxyapatite (HAP) in a soil-rice system, a pot experiment was conducted using Pb-contaminated soil amended with various rates of HAP and planted with rice (Oryza sativa L.). The Pb species in the soil and rice roots were determined using Pb L3-edge X-ray absorption near edge structure (XANES).

Soil Phosphorus Pools, Bioavailability and Environmental Risk in Response to the Phosphorus Supply in the Red Soil of Southern China.

Excess phosphorus (P) accumulation in the soil can change the bioavailability of P and increase the leaching risks, but the quantitative evaluation of these responses in acidic red soil is lacking. This study aimed to investigate the composition of soil P fractions under different phosphorus apparent balances (PAB) in acidic red soil and the bioavailability and the leaching change-points of different P fractions. Five phosphorus (P) fertilization rates were applied (0, 16.

Removal of heavy metals from contaminated paddy soils using chemical reductants coupled with dissolved organic carbon solutions.

General acid washing is commonly used to treat heavy metal-contaminated soils, but it is sometimes difficult to achieve remediation aims in severely polluted soils. If we expose the surfaces of Fe oxide minerals to reductive dissolution during washing treatment, more of the metals initially adsorbed to these surfaces will be liberated, which may encourage the removal of heavy metals. Initially, the metal extraction capabilities of nine chemical reductants were compared in ten soil samples polluted by Cr, Cu, Zn, and Ni.

Adsorption mechanisms of chromate and phosphate on hydrotalcite: A combination of macroscopic and spectroscopic studies.

Hydrotalcite (HT) is a layered double hydroxide (LDH), which is considered as a potential adsorbent to remove anion contaminants. In this study, adsorption of chromate (CrO) and phosphate (PO) on HT was conducted at various pH and temperatures. Related adsorption mechanisms were determined via the isotherm, kinetic, and competitive adsorption studies as well as the Cr K-edge X-ray absorption fine-structure (XAFS) spectroscopy.

Distribution and transformation of lead in rice plants grown in contaminated soil amended with biochar and lime.

This study aimed to investigate the effects of rice straw biochar and lime (RBL) on the remediation of lead (Pb)-contaminated soil and mitigation of Pb translocation in rice plants by using pot experiments. Lead-contaminated soil collected from a farmland near a Pb-zinc (Zn) mine, biochar, limestone powder, and indica rice (Oryza sativa L.) were used in the present study.

Removal of methylene blue from aqueous solution using sediment obtained from a canal in an industrial park.

Drainage canal sediments in an industrial park are generally dredged to landfill in Taiwan. The objective of this study was to evaluate feasibility employing the sediment as an adsorbent for removal of dye. The sediment contained approximately 10% of organic matter and little heavy metals.

Cadmium phytoextraction potential of king grass (Pennisetum sinese Roxb.) and responses of rhizosphere bacterial communities to a cadmium pollution gradient.

Screening for tolerant and high biomass producing plants is important for phytoextraction efforts in remediating agricultural soils contaminated by heavy metals. We carried out a greenhouse experiment involving a soil cadmium (Cd) concentration gradient (0.1, 0.

Bacillus praedii sp. nov., isolated from purplish paddy soil.

A Gram-stain-positive, rod-shaped, endospore-forming, aerobic bacterium, designated strain FJAT-25547T, was isolated from the purplish paddy soil collected from Linshan Township, Yanting Prefecture of Sichuan Province in PR China (31° 16' N 105° 27' E). Growth was achieved aerobically at temperatures between 15 and 40 °C (optimum 30 °C), with between 0 and 10.0 % NaCl (w/v) (optimum 4 %) and in the range of pH 5.

Biochar amendment immobilizes lead in rice paddy soils and reduces its phytoavailability.

This study aimed to determine effects of rice straw biochar on Pb sequestration in a soil-rice system. Pot experiments were conducted with rice plants in Pb-contaminated paddy soils that had been amended with 0, 2.5, and 5% (w/w) biochar.

Molecular Structures of Al/Si and Fe/Si Coprecipitates and the Implication for Selenite Removal.

Aluminum and iron oxides have been often used in the coagulation processes during water purification due to their unique surface properties toward anions. In the presence of silica, the coprecipitation of Al/Si or Fe/Si might decrease the efficiency of wastewater purification and reuse. In this study, surface properties and molecular structures of Al/Si and Fe/Si coprecipitates were characterized using spectroscopic techniques.

Effectiveness of lime and peat applications on cadmium availability in a paddy soil under various moisture regimes.

In paddy soils, amendments and moisture play important role in the immobilization of cadmium (Cd). The effects of applying lime, peat, and a combination of both on soil Eh, pH, and Cd availability in contaminated soils were investigated under wetted (80 ± 5 % of water holding capacity) and flooded (completely submerged) conditions. In wetted soils, there was little change in Eh, compared to flooded soils where Eh reduced rapidly.

Shifts in the pelagic ammonia-oxidizing microbial communities along the eutrophic estuary of Yong River in Ningbo City, China.

Aerobic ammonia oxidation plays a key role in the nitrogen cycle, and the diversity of the responsible microorganisms is regulated by environmental factors. Abundance and composition of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) were investigated in the surface waters along an environmental gradient of the Yong River in Ningbo, East China. Water samples were collected from three pelagic zones: (1) freshwaters in the urban canals of Ningbo, (2) brackish waters in the downstream Yong River, and (3) coastal marine water of Hangzhou Bay.

Reclamation of zinc-contaminated soil using a dissolved organic carbon solution prepared using liquid fertilizer from food-waste composting.

A liquid fertilizer obtained through food-waste composting can be used for the preparation of a dissolved organic carbon (DOC) solution. In this study, we used the DOC solutions for the remediation of a Zn-contaminated soil (with Zn concentrations up to 992 and 757 mg kg(-1) in topsoil and subsoil, respectively). We then determined the factors that affect Zn removal, such as pH, initial concentration of DOC solution, and washing frequency.

Mechanism of Arsenic Adsorption on Magnetite Nanoparticles from Water: Thermodynamic and Spectroscopic Studies.

Removal of arsenic (As) from water supplies is needed to reduce As exposure through drinking water and food consumption in many regions of the world. Magnetite nanoparticles (MNPs) are promising and novel adsorbents for As removal because of their great adsorption capacity for As and easy separation. This study aimed to investigate the adsorption mechanism of arsenate, As(V), and arsenite, As(III), on MNPs by macroscopic adsorption experiments in combination with thermodynamic calculation and microspectroscopic characterization using synchrotron-radiation-based X-ray absorption spectroscopy (XAS) and X-ray photoelectron spectroscopy (XPS).

Bacillus taiwanensis sp. nov., isolated from a soil sample from Taiwan.

A Gram-stain-positive, rod-shaped, endospore-forming, aerobic bacterium (FJAT-14571(T)) was isolated from a soil sample in Taiwan. Strain FJAT-14571(T) grew at 20-40 °C (optimum 35 °C), pH 6-10 (optimum pH 8) and 0-2% (w/v) NaCl (optimum 0%). Phylogenetic analyses based on 16S rRNA gene sequences showed that strain FJAT-14571(T) was a member of the genus Bacillus and was most closely related to Bacillus oceanisediminis DSM 24771(T) (96.

Kinetic and thermodynamic studies on removal of Cu(II) from aqueous solutions using soil nanoclays.

Soil clays (< 2,000 nm) (SC) and soil nanoclays (< 100 nm) (SNC) were used as adsorbents for removal of Cu(II) from aqueous solution. The experiments were conducted with variables including pH, interaction time, concentration of Cu(II) and temperature. Four kinetic models have been employed to investigate adsorption mechanisms, and the experimental data more closely resemble a second-order process of the kinetic model.

Bacillus cihuensis sp. nov., isolated from rhizosphere soil of a plant in the Cihu area of Taiwan.

A Gram-positive, moderately halotolerant, rod-shaped, spore forming bacterium, designated strain FJAT-14515(T) was isolated from a soil sample in Cihu area, Taoyuan County, Taiwan. The strain grew at 10-35 °C (optimum at 30 °C), pH 5.7-9.

Biogeochemical reductive release of soil embedded arsenate around a crater area (Guandu) in northern Taiwan using X-ray absorption near-edge spectroscopy.

This study investigates biogeochemical reductive release of arsenate from beudantite into solution in a crater area in northern Taiwan, using a combination of X-ray absorption near-edge structure (XANES) and atomic absorption spectrometry. Total arsenic (As) concentrations in the soil were more than 200 mg/kg. Over four months of laboratory experiments, less than 0.

Adsorption of Cu(II) from aqueous solution by wine processing waste sludge.

Wine processing waste sludge (WPWS) has been shown to be an effective sorbent for sorption of nickel, lead, and chromium, but the sorption of copper (Cu) in aqueous solution by WPWS has not been conducted. The objective of this study was to explore the sorption mechanism of WPWS for copper. Infrared analysis revealed carboxyl was the major functional group in WPWS.

Removal of methylene blue from aqueous solution using wine-processing waste sludge.

Dye wastewaters usually contain toxins and high chroma, making them difficult to treat with biological methods. The adsorption process plays an important role in removing dyes from wastewaters. This study aimed to explore the methylene blue (MB) adsorption mechanism by wine-processing waste sludge (WPWS).

Remediation of copper polluted red soils with clay materials.

Attapulgite and montmorillonite were utilized to remediate heavy metal polluted red soils in Guixi City, Jiangxi Province, China. The effects of clay minerals on availability, chemical distribution, and biotoxicity of Cu and Zn were evaluated. The results provided a reference for the rational application of clay materials to remediate heavy metal contaminated soils.

Biosorption of chromium, copper and zinc by wine-processing waste sludge: single and multi-component system study.

Wine-processing waste sludge (WPWS) has been shown to have powerful potential for sorption of some heavy metals (i.e., chromium, lead and nickel) in single-component aqueous solutions.

Removal of benzene and toluene by carbonized bamboo materials modified with TiO2.

Carbonized moso bamboo (Phyllostachys pubescens) was coated with TiO(2) nanoparticles to enhance its removal efficiency of harmful gases. Carbonized bamboo-TiO(2) composite (CBC) was prepared by heating mixtures of carbonized bamboo powder (CB) and TiO(2) nanoparticles, denoted as CBM, under nitrogen condition. TiO(2) nanoparticle and carbonized bamboo powder were mixed with the mass ratios of 1/1 and 2/1, respectively.