Absorption and translocation of sulfometuron-methyl in sugarcane (Saccharum officinarum L.) at different growth stages

ABSTRACT

In Brazil, weed management in sugarcane fields is mainly done with the use of selective herbicide formulations. For many years, diuron+hexazinone was one of the main herbicide mixture formulations used in sugarcane. Later, sulfometuron-methyl was included in the same mixture, which was marketed as a new herbicide formulation for residual in-season weed control in sugarcane. The mixture diuron+hexazinone+sulfometuron-methyl has been widely used in commercial sugarcane fields in Brazil. However, recent field observations have shown that sugarcane plants at different growth stages varied in their phytotoxicity levels after treatment with diuron+hexazinone+sulfometuron-methyl. Greenhouse and laboratory studies were conducted to determine ¹⁴Csulfometuron-methyl absorption and translocation, as well as ¹⁴C distribution in sugarcane at two growth stages, 2 to 3 leaves and 5 to 6 leaves. ¹⁴Csulfometuron-methyl absorption by sugarcane did not differ between the two growth stages. Different patterns of ¹⁴C accumulation were observed, which may explain variations in sulfometuron-methyl phytotoxic responses observed in the field.     

Fabrication of novel bio-adsorbent and its application for the removal of Cu(II) from aqueous solution

Environmental Science and Pollution Research - As eco-friendly adsorption material, hydroxyapatite (Ca5(PO4)3OH, HA) has been extensively applied to the removal of heavy metal ions. However,...     

A conflict measure model and its application to supplier evaluation under environmental uncertainty

As environmental issues are of increased concern, many enterprises have participated in some forms of green-purchasing initiatives. Beside the traditional criteria, the supplier's environmental consciousness, environmental mission, advances in developing environmentally friendly goods, etc., should be evaluated. The attitude difference among supply chain partners will create potential problems for their cooperation and collaboration. A conflict evaluation method is proposed based on measuring their inconsistent attitudes toward important issues such as the environmental ones. A model is built for discovering weight parameters from experience. A pre-qualification process is suggested for screening the suppliers by eliminating those conflicts with the buyer firm.     

A novel approach to predict aquatic toxicity from molecular structure

The main aim of the study was to develop quantitative structure-activity relationship (QSAR) models for the prediction of aquatic toxicity using atom-based non-stochastic and stochastic linear indices. The used dataset consist of 392 benzene derivatives, separated into training and test sets, for which toxicity data to the ciliate Tetrahymena pyriformis were available. Using multiple linear regression, two statistically significant QSAR models were obtained with non-stochastic (R2=0.791 and s=0.344) and stochastic (R2=0.799 and s=0.343) linear indices. A leave-one-out (LOO) cross-validation procedure was carried out achieving values of q2=0.781 (scv=0.348) and q2=0.786 (scv=0.350), respectively. In addition, a validation through an external test set was performed, which yields significant values of Rpred2 of 0.762 and 0.797. A brief study of the influence of the statistical outliers in QSAR's model development was also carried out. Finally, our method was compared with other approaches implemented in the Dragon software achieving better results. The non-stochastic and stochastic linear indices appear to provide an interesting alternative to costly and time-consuming experiments for determining toxicity.     

Green preparation of a novel red mud@carbon composite and its application for adsorption of 2,4-dichlorophenoxyacetic acid from aqueous solution

This study reports the eco-friendly preparation of a novel composite material consisting of red mud and carbon spheres, denoted as red mud@C composite, and its application for the removal of 2,4-dichlorophenoxyacetic acid herbicide (2,4-D) from aqueous solution. The preparation route has a green approach because it follows the low-energy consuming one-step hydrothermal process by using starch as a renewable carbon precursor and red mud as a waste from aluminum production industry. Characterization of the red mud@C composite was performed by FT-IR, TGA, SEM, TEM, BET, XRD, and Raman microscopy analyses. The batch adsorption studies revealed that the red mud@C composite has higher 2,4-D adsorption efficiency than those of the red mud and the naked carbon spheres. The maximum removal at initial pH of 3.0 is explained by considering the pKa of 2,4-D and pH of point of zero charge (pH_pzc) of the composite material. The adsorption equilibrium time was 60 min, which followed the pseudo-second-order kinetic model together with intra-particle diffusion model. The isotherm analysis indicated that Freundlich isotherm model better represented the adsorption data, with isotherm parameters of k [15.849 (mg/g) (mg/L)^?1/n] and n (2.985). The prepared composite is reusable at least 5 cycles of adsorption-desorption with no significant decrease in the adsorption capacity.

     

Production of granular activated carbon from food-processing wastes (walnut shells and jujube seeds) and its adsorptive properties

Commercial activated carbon is a highly effective absorbent that can be used to remove micropollutants from water. As a result, the demand for activated carbon is increasing. In this study, we investigated the optimum manufacturing conditions for producing activated carbon from ligneous wastes generated from food processing. Jujube seeds and walnut shells were selected as raw materials. Carbonization and steam activation were performed in a fixed-bed laboratory electric furnace. To obtain the highest iodine number, the optimum conditions for producing activated carbon from jujube seeds and walnut shells were 2 hr and 1.5 hr (carbonization at 700°C) followed by 1 hr and 0.5 hr (activation at 1000°C), respectively. The surface area and iodine number of activated carbon made from jujube seeds and walnut shells were 1,477 and 1,184 m²/g and 1,450 and 1,200 mg/g, respectively. A pore-distribution analysis revealed that most pores had a pore diameter within or around 30–40 Å, and adsorption capacity for surfactants was about 2 times larger than the commercial activated carbon, indicating that waste-based activated carbon can be used as alternative.

Implications:Wastes discharged from agricultural and food industries results in a serious environmental problem. A method is proposed to convert food-processing wastes such as jujube seeds and walnut shells into high-grade granular activated carbon. Especially, the performance of jujube seeds as activated carbon is worthy of close attention. There is little research about the application of jujube seeds. Also, when compared to two commercial carbons (Samchully and Calgon samples), the results show that it is possible to produce high-quality carbon, particularly from jujube seed, using a one-stage, 1,000°C, steam pyrolysis. The preparation of activated carbon from food-processing wastes could increase economic return and reduce pollution.     

剩余污泥制备活性炭及其应用研究

以城市污水处理厂二沉池排出的剩余污泥为原料,采用不同活化方法制备活性炭,同时对比活化效果,研究了制备工艺条件对污泥活性炭吸附性能及产率的影响。结合比表面积、孔径分布和扫描电镜表征分析,对制备的污泥活性炭的性能进行评价,并探讨了污泥活性炭作为水处理吸附剂的去除效果。结果表明,以ZnCl2为活化剂制备的活性炭性能较好,其最佳制备条件为：活化温度550℃,活化时间45 min,ZnCl2浓度40％,固液比1∶2。制得的污泥活性炭的碘吸附值为496 mg/g,产率为51.8％,比表面积为301.4 m2/g,孔体积为0.37 mL/g,微孔体积为0.08 mL/g,平均孔径为5.78 nm。将该产品用于处理城市污水,投加量为0.8％,吸附平衡时间约为60 min时,对COD的去除率为81％,吸附容量为42.53 mg/g。     

改性凹凸棒土的优化定向制备及对腐殖酸的吸附效果

以天然凹凸棒土为原料,以去除以腐殖酸为代表的天然有机物为目的,研究酸活化、热处理和十八烷基三甲基氯化铵(OTAC)有机改性3种改性方法,进行定向筛选。进一步比较3种方法联合改性凹土后对腐殖酸的吸附效果,确定最优定向改性方法。结果表明,先酸处理后OTAC改性凹土对腐殖酸的吸附效果最好,改性凹土投药量为0.7 g/L时,腐殖酸的去除率可达97%。利用正交实验确定凹土改性的最佳工艺条件、钠化时间和有机改性剂的用量对改性凹土吸附腐殖酸的能力影响显著。改性的最佳工艺条件为:酸浓度3 mol/L,氯化钠浓度0.5 mol/L,钠化时间2 h,改性剂用量为凹土质量的3%,微波改性时间为9 min。单独投加改性凹土时pH值对腐殖酸的吸附效果有重要影响。该方法制备的改性凹土在水处理工艺有良好的应用前景。     

Synthesis, characterization and application of a novel chemical sand-fixing agent-poly(aspartic acid) and its composites

A novel sand-fixing agent-poly(aspartic acid) and its composites were synthesized to improve sand particles compressive strength and anti-wind erosion properties. The relationship between the concentration of sand-fixing agent and the sand-fixing properties was studied by three kinds of aging tests. Some composites were choose to improve the sand-fixing property and the composition of 40% xanthan gum and 60% ethyl cellulose were chosen to compare sand-fixing property with lignosulfonate. The results showed that the sand-fixing and water-retaining properties of xanthan gum and ethyl cellulose composites were better than that of lignosulfonate. The biodegradability experiment showed that the PASP and its composites were environment-friendly products and the field test showed that the PASP composites could improve wind erosion disturbance.     

Monoclonal antibody produced by heterologous indirect enzyme-linked immunosorbent assay and its application for parathion residue determination in agricultural and environmental samples

A heterologous indirect enzyme-linked immunosorbent assay (ELISA) was developed, which was based on monoclonal antibody (Mab) to determine parathion residue in agricultural and environmental samples. Eight Mabs were produced by introducing the heterologous indirect ELISA into the screening procedure. It was shown that these Mabs had more broad-reactivity with twenty competitors than that of 5H7 (Mab produced by homologous screening). So it became much easier using these new Mabs to develop heterologous immunoassays. In addition, all the developed heterologous ELISAs could be used to determine parathion residue in semiquantitative or quantitative level, and their detection limitation (LOD) was around 2 ng/mL. Compared with the previous heterologous ELISA (hapten 11/5H7) with IC₅₀ of 13.3 ng/mL, a better heterologous ELISA (hapten 11/1E1) was obtained with IC₅₀ of 3.8 ng/mL, which improved the sensitivity 3.5 times. Finally, the latter was applied to parathion residue determination in spiked agricultural and environmental samples without extraction or cleanup. The average recoveries of parathion added to water, soil, cucumber, Chinese cabbage and carrot were between 80.4 % and 111.8 %. The LOD for water and soil samples was 5 ng/mL, and the LOD for cucumber, rice and corn samples was 10 ng/mL.     

A context-intensive approach to imputation of missing values in data sets from networks of environmental monitors

Although networks of environmental monitors are constantly improving through advances in technology and management, instances of missing data still occur. Many methods of imputing values for missing data are available, but they are often difficult to use or produce unsatisfactory results. I-Bot (short for “Imputation Robot”) is a context-intensive approach to the imputation of missing data in data sets from networks of environmental monitors. I-Bot is easy to use and routinely produces imputed values that are highly reliable. I-Bot is described and demonstrated using more than 10 years of California data for daily maximum 8-hr ozone, 24-hr PM_2.5 (particulate matter with an aerodynamic diameter <2.5 μm), mid-day average surface temperature, and mid-day average wind speed. I-Bot performance is evaluated by imputing values for observed data as if they were missing, and then comparing the imputed values with the observed values. In many cases, I-Bot is able to impute values for long periods with missing data, such as a week, a month, a year, or even longer. Qualitative visual methods and standard quantitative metrics demonstrate the effectiveness of the I-Bot methodology.Implications: Many resources are expended every year to analyze and interpret data sets from networks of environmental monitors. A large fraction of those resources is used to cope with difficulties due to the presence of missing data. The I-Bot method of imputing values for such missing data may help convert incomplete data sets into virtually complete data sets that facilitate the analysis and reliable interpretation of vital environmental data.     

Isolation and characterization of novel phorate-degrading bacterial species from agricultural soil

Based upon 16S rDNA sequence homology, 15 phorate-degrading bacteria isolated from sugarcane field soils by selective enrichment were identified to be different species of Bacillus, Pseudomonas, Brevibacterium, and Staphylococcus. Relative phorate degradation in a mineral salt medium containing phorate (50 μg ml^?1) as sole carbon source established that all the bacterial species could actively degrade more than 97 % phorate during 21 days. Three of these species viz. Bacillus aerophilus strain IMBL 4.1, Brevibacterium frigoritolerans strain IMBL 2.1, and Pseudomonas fulva strain IMBL 5.1 were found to be most active phorate metabolizers, degrading more than 96 % phorate during 2 days and 100 % phorate during 13 days. Qualitative analysis of phorate residues by gas liquid chromatography revealed complete metabolization of phorate without detectable accumulation of any known phorate metabolites. Phorate degradation by these bacterial species did not follow the first-order kinetics except the P. fulva strain IMBL 5.1 with half-life period (t½) ranging between 0.40 and 5.47 days.     

A novel application of H2O2-Fe(II) process for arsenate removal from synthetic acid mine drainage (AMD) water

Batch experiments were carried out to investigate the influences of H₂O₂/Fe(II) molar ratio, pH, sequence of pH adjustment, initial As(V) concentration, and interfering ions on As(V) removal in H₂O₂-Fe(II) process from synthetic acid mine drainage (AMD). The optimum H₂O₂/Fe(II) molar ratio was one for arsenate removal over the pH range of 4-7. Arsenate removal at pH 3 was poor even at high Fe(II) dosage due to the high solubility of Fe(III) formed in situ. With the increase of Fe(II) dosage, arsenate removal increased progressively before a plateau was reached at pH 5 as arsenate concentration varied from 0.05 to 2.0 mg L⁻¹. However, arsenate removal was negligible at Fe/As molar ratio <3 and then experienced a striking increase before a plateau was reached at pH 7 and arsenate concentration ≥1.0 mg L⁻¹. The co-occurring ions exerted no significant effect on arsenate removal at pH 5. The experimental results with synthetic AMD revealed that this method is highly selective for arsenate removal and the co-occurring ions either improved arsenate removal or slightly depressed arsenate removal at pH 5-7. The extended X-ray absorption fine structure (EXAFS) derived As-Fe length, 3.27-3.30 Å, indicated that arsenate was removed by forming bidentate-binuclear complexes with FeO(OH) octahydra. The economic analysis revealed that the cost of the H₂O₂-Fe(II) process was only 17-32% of that of conventional Fe(III) coagulation process to achieve arsenate concentration below 10 μg L⁻¹ in treated solution. The results suggested that the H₂O₂-Fe(II) process is an efficient, economical, selective and practical method for arsenate removal from AMD.     

厨余垃圾短程发酵产物的性质及其反硝化性能

针对厨余垃圾的短程自由发酵过程,考察了不同初始固体浓度在60 h内对发酵过程和发酵产物的影响,结果表明,短程自由发酵是一种不完全的水解酸化过程,初始固体浓度为（13±0.5）%时有机酸（以COD计）产量最高（16.56 g·L-1）。短程发酵液是以碳水化合物为主,同时也包含了乳酸、乙酸、蛋白质和丁酸等的混合物碳源。发酵液的反硝化性能通过硝酸盐利用速率（NUR）实验来验证,结果表明COD/N=6是最优条件,该条件下的反硝化速率vDN=12.89 mg·（g·h）-1（以VSS计）和反硝化能力PDN=0.174 g·g-1（以COD计）,同时短程发酵液中快速降解有机物组分为58.35%。     

Layered double hydroxides functionalized by carbonaceous materials: from preparation to energy and environmental applications

Environmental Science and Pollution Research - Along with the exponential demand for energy and pollution-free-environment, layered double hydroxides (LDHs) have gained extensive explorations...     

Mitigating environmental degradation with institutional quality and foreign direct investment (FDI): new evidence from asymmetric approach

Environmental Science and Pollution Research - Chile is currently rated among the performing countries towards the achievement of the global goals of reducing carbon emission. It is on recorded...     

新型环保型自来水絮凝剂的研制及应用

根据“有机-无机”絮凝剂相复合协同增效的原则,研制出一种高效的复合环保型自来水絮凝剂,使其处理效果与传统絮凝剂比较,浊度下降0．65％,药剂成本下降9．29％,出水铝离子浓度比传统下降77．3％,无论从产品的性价比还是从环境友好等方面均明显优于传统的自来水絮凝剂,具有明显的经济与环境效益。     

Hierarchical eco-restoration: A systematical approach to removal of COD and dissolved nutrients from an intensive agricultural area

A systematical approach based on hierarchical eco-restoration system for the simultaneous removal of COD and dissolved nutrients was proposed and applied in a complex residential-cropland area in Kunming, China from August 2006 to August 2008, where the self-purifying capacity of the agricultural ecosystem had been lost. The system includes four main parts: (1) fertilizer management and agricultural structure optimization, (2) nutrients reuse, (3) wastewater treatment, and (4) catchment restoration. The results showed that the average removal efficiencies were 90% for COD, 93% for ammonia, 94% for nitrate and 71% for total dissolved phosphorus (TDP) when the hierarchical eco-restoration agricultural system was in a relatively steady-state condition. The emergence of 14 species of macrophytes and 4 species of zoobenthos indicated that the growth conditions for the plankton were improved. The results demonstrated that this promising and environmentally benign hierarchical eco-restoration system could decrease the output of nutrients and reduce downstream eutrophication risk.     

The preparation of calcium phosphate adsorbent from natural calcium resource and its application for copper ion removal

Environmental Science and Pollution Research - Using the hen eggshells (biowaste) as a source of calcium and an environmentally friendly approach, the nanopowder composed of 74% of hydroxyapatite...     

基于废弃桑枝的新型絮凝剂的制备及应用研究

针对栽桑养蚕过程中废弃桑枝的综合利用,以废弃桑枝和十六烷基三甲基溴化铵为原料,经微波辐射加热制备高分子絮凝剂。通过单因素实验确定了制备絮凝剂的最佳工艺条件,并采用该絮凝剂处理造纸废水。结果表明,制备絮凝剂的最佳工艺条件为:NaOH溶液浓度为8%,碱化温度为室温,碱化时间为30 m in,Fe2+/H2O2的加入量为14 mmol/L,桑枝粉与十六烷基三甲基溴化铵的质量比为1∶1,微波功率为500 W,反应温度为90℃,反应时间为60 m in。制备的絮凝剂对造纸废水具有高效絮凝性能,在造纸废水pH值为10,絮凝剂投加量为100 mg/L的条件下,COD和浊度去除率分别达48.2%和81.4%。该絮凝剂对造纸废水的絮凝效果明显优于氯化铝,与聚合氯化铝相当,但其用量明显低于氯化铝和聚合氯化铝。