This article provides a critical review of the environmental chemistry of inorganic antimony (Sb) in soils, comparing and contrasting findings with those of arsenic (As). Characteristics of the Sb soil system are reviewed, with an emphasis on speciation, sorption and phase associations, identifying differences between Sb and As behaviour. Knowledge gaps in environmentally relevant Sb data for soils are identified and discussed in terms of the limitations this imposes on understanding the fate, behaviour and risks associated with Sb in environmental soil systems, with particular reference to mobility and bioavailability.

The present work investigated the adsorption of Sb(III) and Sb(V) on five sediment samples (Pearl River, Yangtze River, Yellow River, Yongding River, and Liao River) from typical water systems in China and the adsorption of Sb(V) on Pearl River sediment with different organic carbon (OC) fractions using batch experiments. In order to assess the contributions of sedimentary organic components to the overall adsorption of pentavalent Sb on sediments, one sediment sample was treated by commonly used chemical and physical methods to remove different organic components. Experimental data of Sb(III) and Sb(V) adsorption on five sediments were successfully modeled using the Freundlich (r2 > 0.96) isotherm. In general, the sediments with high Fe and Al oxide contents and total organic carbon (TOC) had higher Sb(III) and Sb(V) adsorption than the sediments containing small amounts of Fe and Al oxides and TOC. Dissolved organic carbon (DOC) in sediment promoted the adsorption of Sb(V), and humin fractions and black carbon-like material in sediment had a high affinity for Sb(V).

The present work investigated the adsorption and mobility (desorption) of Sb(V) on kaolinite using batch experiments. The adsorption of Sb(V) on kaolinite was studied as a function of contact time, pH, ionic strength, humic acid (HA), initial Sb(V) concentration and temperature. Kinetic studies suggest that the equilibrium is achieved within 24 h. The adsorption of Sb(V) was strongly affected by changes in I at low ionic strength and unaffected at high ionic strength. The adsorption is weakly dependent on the presence of humic acid, but is strongly dependent on pH. Within the range tested, the optimal pH for Sb(V) adsorption is 3.6, and close to 75% removal can be achieved. Desorption is dependent on the original suspension pH. The addition sequence of Sb(V)/HA do not influence the adsorption of Sb(V) on kaolinite. The adsorption data fit both the Freundlich and Langmuir isotherm. The thermodynamic parameters (ΔH0, ΔS0 and ΔG0) were calculated from the temperature dependence, and the results suggest the endothermic and spontaneous nature of the process.

The increasing interest in urban agriculture highlights the crucial question of crop quality. The main objectives for environmental sustainability are a decrease in chemical inputs, a reduction in the level of pollutants, and an improvement in the soil's biological activity. Among inorganic pollutants emitted by vehicle traffic and some industrial processes in urban areas, antimony (Sb) is observed on a global scale. While this metalloid is known to be potentially toxic, it can transfer from the soil or the atmosphere to plants, and accumulate in their edible parts. Urban agriculture is developing worldwide, and could therefore increasingly expose populations to Sb. The objective of this review was in consequences to gather and interpret actual knowledge of Sb uptake and bioaccumulation by crops, to reveal investigative fields on which to focus. While there is still no legal maximal value for Sb in plants and soils, light has to be shed on its accumulation and the factors affecting it. A relative absence of data exists about the role of soil flora and fauna in the transfer, speciation and compartmentation of Sb in vegetables. Moreover, little information exists on Sb ecotoxicity for terrestrial ecosystems. A human risk assessment has finally been reviewed, with particular focus on Sb bioaccessibility.

The experiment of artificial afforestation combining with soil amendment was carried out to investigate the effects of soil amendment on antimony (Sb) chemical forms, and its bioavailability in Chinese antimony mining. This research provides the technical basis for ecological remediation of Sb contaminated soils. The results showed that the soil pH values increased with the increasing of discharging amount of soil amendment. While using 300 g soil amendment on each plant, the soil pH value changed from acidic to alkaline. Soil amendment had significant effect in 0-20 and 40-60 cm soil layers on carbonate-bound Sb and had very significant effect in 20-40 cm soil layer, and very significant effect on residual form in 40-60 cm. The FeMn oxide- and organic-bound and residual forms mainly exist in 0-20 cm and 20-40 cm depth of soils in antimony mining. However, organic- and FeMn oxide-bound Sb exist in 40-60 cm depth of soil. The amendment addition increased Sb bioavailability by 18.92-24.23%, and decreased Sb potential bioavailability and Sb non-bioavailability by 17.55-18.92% and 0.95-6.03%, respectively.

In order to investigate the phenomenon of bioaccumulation of heavy metals in Broussonetia papyrifera, we selected plants which grew in the forests with or without serious heavy metal (Sb, As, Cd and Hg) contamination. Our findings showed no difference in the biomass and structures of various organs between the Broussonetia papyrifera plants in the heavy-metal contaminated locations in the antimony mine area and uncontaminated. The accumulation amounts of Sb, Pb, Cd, Hg, As, Cu and Zn in the roots, branches, stems and leaves of Broussonetia papyrifera plants showed very significant difference between the contaminated and uncontaminated locations. Broussonetia papyrifera is a woody plant that has a strong capacity for accumulating various heavy metals such as Sb, Zn, Pb and As. The sequence in which the heavy metals such as Sb, As and Pb accumulate in Broussonetia papyrifera in the contaminated locations was leaves>branches>stems>roots, and the sequence of Zn-accumulation was leaves>branches>roots>stems. The amounts of Sb, Zn, Pb and As accumulated by whole plants of Broussonetia papyrifera in the contaminated locations were 155.85, 150.12, 37.56 and 18.9033 mg kg -1 , respectively. Of these amounts, 85% of heavy metals were accumulated in the aerial parts of Broussonetia papyrifera, and more than 60% in the leaves. These findings showed that Sb, Zn, Pb and As accumulate mainly in the leaves and branches of Broussonetia papyrifera. Broussonetia papyrifera could be the ideal candidate for ecological and vegetation restorations in the locations contaminated by heavy metals in antimony mines.

Five British former mining and smelting sites were investigated and found to have levels of total Sb of up to 700 mg kg(-1), indicating high levels of contamination which could be potentially harmful. However, this level of Sb was found to be biologically unavailable over a wide range of pH values, indicating that Sb is relatively unreactive and immobile in the surface layers of the soil, remaining where it is deposited rather than leaching into lower horizons and contaminating ground water. Sb, sparingly soluble in water, was unavailable to the bacterial biosensors tested. The bioluminescence responses were correlated to levels of co-contaminants such as arsenic and copper, rather than to Sb concentrations. This suggests that soil contamination by Sb due to mining and smelting operations is not a severe risk to the environment or human health provided that it is present as immobile species and contaminated sites are not used for purposes which increase the threat of exposure to identified receptors. Co-contaminants such as arsenic and copper are more bioavailable and may therefore be seen as a more significant risk.

Environmental context. Soil contamination by antimony (Sb) has become an environmental problem of much concern in recent years, because increasing mining and industrial use has led to widespread soil contamination by this biologically unessential, but potentially carcinogenic element. We reviewed the available literature and found that Sb is generally taken up by terrestrial plants in proportion to the concentration of soluble Sb in soil over a concentration range covering five or more orders of magnitude, a finding that is relevant in particular for the assessment of environmental and health risks arising from Sb-contaminated soils. But very little is known about the mechanisms of Sb uptake by plants. Abstract. Soil contamination by antimony (Sb) due to human activities has considerably increased in the recent past. We reviewed the available literature on Sb uptake by plants and toxicity risks arising from soil contamination by Sb and found that Sb is generally taken up by terrestrial plants in proportion to the concentration of soluble Sb in soil over a concentration range covering five or more orders of magnitude. However, very little is known about the mechanisms of Sb uptake by plants. Also the deposition of resuspended soil particles on the surfaces of aerial plant surfaces can result in high plant Sb concentration in the vicinity of Sb-contaminated sites. Although soil pollution by Sb may be rarely so severe as to cause toxicity problems to humans or animals consuming plants or food derived from plants grown on Sb-contaminated sites, such risks may arise under worst-case conditions.

Environmental context. Concern over the presence of antimony (Sb) in the environment because of chemical similarities with arsenic (As) has prompted a need to better understand its environmental behaviour and risks. The present study investigates the bioaccumulation and uptake of antimony in a highly contaminated stream near the Hillgrove antimony–gold mine in NSW, Australia, and reports high Sb (and As) concentrations in many components of the ecosystem consisting of three trophic levels, but limited uptake into aboveground parts of riparian vegetation. The data suggest that Sb can transfer into upper trophic levels of a creek ecosystem, but that direct exposure of creek fauna to creek sediment and soil, water and aquatic autotrophs are more important metalloid uptake routes than exposure via riparian vegetation. Abstract. Bioaccumulation and uptake of antimony (Sb) were investigated in a highly contaminated stream, Bakers Creek, running adjacent to mining and processing of Sb–As ores at Hillgrove Mine, NSW, Australia. Comparisons with arsenic (As) were included owing to its co-occurrence at high concentrations. Mean metalloid creek rhizome sediment concentrations were 777 ± 115 μg g–1 Sb and 60 ± 6 μg g–1 As, with water concentrations at 381 ± 23 μg L–1 Sb and 46 ± 2 μg L–1 As. Antimony and As were significantly elevated in aquatic autotrophs (96–212 μg g–1 Sb and 32–245 μg g–1 As) but Sb had a lower uptake efficiency. Both metalloids were elevated in all macroinvertebrates sampled (94–316 μg g–1 Sb and 1.8–62 μg g–1 As) except Sb in gastropods. Metalloids were detected in upper trophic levels although biomagnification was not evident. Metalloid transfer to riparian vegetation leaves from roots and rhizome soil was low but rhizome soil to leaf As concentration ratios were up to 2–3 times greater than Sb concentration ratios. Direct exposure to the rhizosphere sediments and soils, water ingestion and consumption of aquatic autotrophs appear to be the major routes of Sb and As uptake for the fauna of Bakers Creek.

Environmental context Scientific knowledge is continuously built up based on research results, and relies on their efficient and accurate dissemination. Using antimony as an example, a system is proposed that combines ease of access with focussed reviews while keeping track of all published work. This system, termed BUKI (Building Up Knowledge Initiative) is a collaborative approach based on the combination of a web-based platform and the elaboration of systematic reviews. Abstract The increasing difficulties experienced by the scientific community in efficiently constructing knowledge from the flood of data being continuously produced are discussed and a concrete solution – a BUKI (Building Up Knowledge Initiative) – proposed for research on the environmental chemistry of antimony. A BUKI is a collaborative approach based on the combination of a web-based platform and the elaboration of systematic reviews. The antimony BUKI described here aims to improve our knowledge of antimony in environmental systems but also to stir up discussion about how research works nowadays and to provide a model for the development of other BUKIs.

Antimony occurs widely in the environment as a result of natural processes and human activity. Although antimony is similar to arsenic in chemical properties and toxicity, and a pollutant of priority interest to the USEPA and the EU, its environmental behaviors, control techniques, and even solution chemistry, are yet barely touched. In this study, antimony removal from drinking water with coagulation-flocculation-sedimentation (CFS) is comprehensively investigated with respect to the dependence of both Sb(III) and Sb(V) removal on the initial contaminant-loading level, coagulant type and dosage, pH and interfering ions. The optimum pH for Sb(V) removal with ferric chloride (FC) was observed at pH 4.5-5.5, and continuously reduced with further pH increase. Over a broad pH range from 4.0 to 10.0, effective Sb(III) removal with FC was obtained. Contrary to the effective Sb removal with FC, the degree of both Sb(III) and Sb(V) removal with aluminum sulfate (AS) was very low, indicating the impracticability of AS application for antimony removal. The presence of phosphate and humic acid (HA) markedly impeded Sb(V) removal, while exhibited insignificant effect on Sb(III) removal. The effects of coagulant type, Sb species and pH are more pronounced than the effects of coagulant dose and initial pollutant concentration. After preliminarily excluding the possibility of precipitation and the predominance of coprecipitation, the adsorption mechanism is used to rationalize and simulate Sb/FC coagulation with good result by incorporating diffuse-layer model (DLM).

Antimony (Sb) pollution has been of growing environmental concern. Little information is available on biosorption of Sb. In the present study, biosorption behavior and mechanisms of Sb(III) to the cyanobacterium Synechocystis sp. cells were investigated by batch experiments and FTIR analysis. Our study shows that Synechocystis sp. cells are a good adsorbent for Sb(III) with a sorption capacity of 4.68 mg·g -1 dry weight adsorbent. The isothermal sorption data can be described by the Langmuir Isotherm and the Freundlich Isotherm. Several mechanisms were involved with biosorption of Sb to Synechocystis sp. cells and sorption to binding sites might be dominant. The sorption kinetics followed the pseudo-second order model. The adsorbed Sb is mainly located in extracellular polysaccharides (EPS) and within the cell, and a small proportion was adsorbed onto the cell wall. The proteins and polysaccharides in EPS and the polysaccharides on the cell are the main functional groups that are responsible for adsorption of Sb to Synechocystis sp. cells.

Antimony (Sb) is ubiquitous throughout the environment as a result of natural processes and human activities. In China, superlarge-, large and medium-sized Sb deposits are concentrated in the Guangxi (34.4%), Hunan (21.2%), Yunnan (12.2%) and Guizhou (10.2%) provinces. Due to Sb mining and smelting processes, large quantities of Sb have been released resulting in serious Sb contamination of the local environments. Furthermore, coal combustion and Sb products consumed by the domestic market are also important potential Sb contamination sources. Here, an integrated overview of the current knowledge on the distribution of Sb in Chinese environments and the human health risk with respect to Sb contamination in Chinese mining and smelting areas are presented. The average Sb concentrations found in soils were divided into three groups. Group 1 had lower Sb concentrations of 0.5-1.5mgkg(-1), Group 2 had medium concentrations of 1.5-2mgkg(-1), and Group 3 had relatively high concentrations of over 2mgkg(-1). Soils from the Yunnan, Guangxi, Guizhou and Hunan provinces were extremely enriched in Sb. Data on the sediment and water mainly came from the Yangtze River water systems and some mining and smelting areas. The Sb concentrations in sediments were of the order of a few mgkg(-1). In water, Sb was mainly concentrated in the particle matter. Higher concentrations in water (up to 29.4mgL(-1)) and sediments (up to 1163mgkg(-1)) were mainly limited to the proximity of mining and smelting areas than the faraway places (<5.00mgL(-1) for water and <3.00mgkg(-1) for sediments, respectively). Plants growing in these contaminated soils accumulated high levels of Sb (up to 143.7mgkg(-1)) and exceeded the tolerable concentration (5mgkg(-1)), thus threatening the health of local inhabitants. The local environments around Sb mining and smelting areas were seriously contaminated.

Antimony (Sb) has received increasing attention recently due to its toxicity and potential human carcinogenicity. In the present work, drinking water, fish and algae samples were collected from the Xikuangshan (XKS) Sb mine area in Hunan, China. Results show that serious Sb and moderate arsenic (As) contamination is present in the aquatic environment. The average Sb concentrations in water and fish were 53.6 + or - 46.7 microg L(-1) and 218 + or - 113 microg kg(-1) dry weight, respectively. The Sb concentration in drinking water exceeded both Chinese and WHO drinking water guidelines by 13 and 3 times, respectively. Antimony and As concentrations in water varied with seasons. Fish gills exhibited the highest Sb concentrations but the extent of accumulation varied with habitat. Antimony enrichment in fish was significantly lower than that of As and Hg.

Abstract This research attempted to study the adsorption of Sb(III) and Sb(V) on bentonite using batch experiments. The effects of reaction time, temperature, initial Sb concentration, and competitive anions at different concentrations on the adsorption of Sb(III) and Sb(V) were investigated. Kinetic studies suggested that the adsorption equilibriums for both Sb(III) and Sb(V) were reached within 24 h. The desorption of Sb adsorbate on the bentonite was observed following Sb(III) adsorption, probably due to the oxidation of Sb(III) on the bentonite surface and subsequent desorption of Sb(V). In addition, oxidation of Sb(III) can occur in the solution medium also, which decreases the concentration of Sb(III) in the solution thereby driving the equilibrium in the direction of desorption from the surface. The adsorption data at three temperatures were successfully modeled using Langmuir (r2 > 0.82) and Freundlich (r2 > 0.99) isotherms. The thermodynamic parameters (ΔG0, ΔH0, and ΔS0) were calculated from the temperature dependence, suggesting that the adsorption process of Sb(III) is spontaneously exothermic, while the adsorption process of Sb(V) is spontaneously endothermic. Competitive anions such as NO 3 − , SO 4 2 − , and PO 4 3 − hardly affected the Sb(III) adsorption on bentonite, while SO 4 2 − and PO 4 3 − could compete with Sb(OH) 6 − for adsorption sites. The competition between PO 4 3 − and Sb(OH) 6 − on adsorption sites was presumably due to the formation of surface complexes and the surface accumulation or precipitation of PO 4 3 − on bentonite surface.

Abstract Many crops cultivated in mining areas have been found to accumulate high levels of antimony (Sb) in their edible parts, thereby causing potential risks to human health. Understanding the behaviours of Sb in plants is important, particularly the mechanisms involved in its uptake, toxicity, detoxification and accumulation in crops. Many factors affect the uptake of Sb in plants, including water management, Sb speciation and some coexisting ions in soils. At present, the mechanisms of Sb uptake by plants have not been fully elucidated so far. The uptake of Sb has been proposed to occur mainly through the passive pathway; however, it is possible that an active pathway exists as well. Antimony can damage plants, including growth retardation, inhibition of photosynthesis, decreases in the uptake of certain essential elements and decreases in the synthesis of certain metabolites. Plants often have defence mechanisms to alleviate Sb toxicity; e.g., a highly efficient antioxidative system and the ability to immobilise Sb in the cell wall or compartmentalise Sb in the cytosol. Such mechanisms have been widely reported in Sb-tolerant and Sb-accumulating plants. In view of the above knowledge, several questions remain: (1) What is the actual uptake pathway of Sb in plants? (2) Does Sb participate in redox reactions within plants? (3) What is the role of metabolic reactions of Sb in Sb toxicity to plants? (4) Can Sb be methylated, and if so, how? (5) How does Sb induce bursts of reactive oxidative species (ROS)?

Abstract Antimony, a pollutant of priority interest by United States Environment Protection Agency (USEPA) and Europe Union (EU), is detected in soil and water with elevated concentration due to its extensive use in a variety of industries. However, antimony purification from liquid system is yet poorly documented. In this study, effect of competing ions on antimony (III/V) removal by ferric chloride (FC) coagulation was comprehensively investigated. At lower FC dose (2× and 4 × 10 −4  mol/L of Fe), the percentage of Sb(V) removal showed a significant and continued decrease with the increasing presence of competing ions, including bicarbonate, sulfate, phosphate, and humic acid (HA). In contrast to Sb(V), Sb(III) removal remained highly effective, and was only slightly affected by the presence of HCO 3 − and SO 4 2− . Phosphate and HA considerably decreased Sb(III) removal at lower coagulant dose. However, with coagulant dose reaching 6 × 10 −4  mol/L of FC, Sb(III) removal became independent of phosphate and HA effect. The mechanism of antimony (III) adsorption onto hydrous ferric oxide (HFO) formed during FC coagulation, combined with a coprecipitation approach of anomalous incorporation of Sb(III) into HFO nanocrystaline, was proposed to interpret the effective Sb(III) removal under various suboptimal conditions. The predominance of Sb(V) adsorption onto HFO, including both surface and internal adsorption, can satisfactorily explain the Sb(V) removal with high sensitivity to competing ion effect.

Abstract Antimony (Sb) pollution has been of a great environmental concern in some areas in China. Sb enters human body via drinking water, inhalation and food chain, unavoidably interacts with human serum albumin (HSA) in blood plasma, and consequently does harm to human health. The harmful effects of Sb on human health depend on the Sb species and their binding ability to HSA. In the present study, binding of three forms of Sb with HSA was investigated by excitation-emission matrix (EEM) spectroscopy. All of antimony potassium tartrate, antimony trichloride and potassium pyroantimonate quenched fluorescence of HSA. Values of conditional stability constant Ka (×105/M) for Sb and HSA systems were 8.13–9.12 for antimony potassium tartrate, 2.51–4.27 for antimony trichloride and 3.63–9.77 for potassium pyroantimonate. The binding constant Kb (×104/M) values of HSA with antimony potassium tartrate, antimony trichloride and potassium pyroantimonate were 0.02–0.07, 3.55–5.01, and 0.07–1.08, respectively. There was one independent class of binding site for antimony trichloride towards HSA. There was more than one Sb binding site and negative cooperativity between multiple binding sites for potassium pyroantimonate and antimony potassium tartrate towards HSA. The binding ability of HSA to complex Sb followed the order: antimony trichloride>potassium pyroantimonate>antimony potassium tartrate.