改性生物炭对弱碱性Cd污染土壤钝化修复效应和土壤环境质量的影响

通过大田示范试验,研究了钙基改性生物炭对弱碱性Cd污染土壤的钝化修复效应及对土壤理化性质、团聚体结构、土壤酶活性和玉米体内Cd累积特征的影响.结果表明,向弱碱性土壤中添加改性生物炭提高了土壤pH值、有效态阳离子交换量和有机质含量.与对照相比,添加钙基改性生物炭后土壤有效态Cd（DTPA-Cd）含量的降幅达到12.0%~30.2%,且Cd赋存形态由活性较高的可交换态和可还原态向更稳定的残渣态转变.改性生物炭的施加明显降低了Cd在植物体内富集的风险,玉米根、茎、叶和籽粒中Cd含量明显受到抑制,3种玉米品种籽粒中Cd含量较对照分别下降了52.65%~72.56%（郑单958）、37.54%~50.80%（蠡玉16）和23.60%~51.20%（三北218）.添加改性生物炭在一定程度上改善了土壤环境质量,土壤过氧化氢酶、脲酶和碱性磷酸酶活性随着改性生物炭施加量的增加呈逐渐升高的趋势.改性生物炭处理下,5~8 mm和2~5 mm粒级团聚体所占比例增加,而≤ 0.25 mm粒级团聚体占比有所下降,团聚体平均几何直径（GMD）和平均质量直径（MWD）分别增加了10.35%~29.34%和13.20%~27.03%,显示土壤团聚体稳定性增加.玉米籽粒中（郑单958）Cd含量与土壤有效态Cd含量呈显著负相关关系（p<0.01）.研究表明,钙基改性生物炭在钝化修复弱碱性Cd污染土壤和改善土壤环境质量方面具有一定的研究前景和可行性.     

Electronic elasticity-toxicity relationships for polychlorinated dibenzo-p-dioxin congeners

SCF-MO computations have been performed on tetra- to octa-chlorinated dibenzo-p-dioxin congeners (PCDD) using an MNDO-PM3 Hamiltonian. Qualitative relationships were developed between empirical, international-toxic equivalence factors for PCDD congeners and their relative (specific) polarizabilities and mean values of second hyperpolarizabilities estimated using finite-field theory.     

Influence of the structure and composition of Fe–Mn binary oxides on rGO on As(III) removal from aquifers

Fe–Mn binary oxide (FMBO) possesses high efficiency for As(III) abatement based on the good adsorption affinity of iron oxide and the oxidizing capacity of Mn(IV), and the composition and structure of FMBO play important roles in this process. To compare the removal performance and determine the optimum formula for FMBO, magnetic graphene oxide (MRGO)–FMBO and MRGO–MnO₂ were synthesized with MRGO as a carrier to improve the dispersity of the adsorbents in aquifers and achieve magnetic recycling. Results indicated that MRGO–FMBO had higher As(III) removal than that of MRGO–MnO₂, although the ratios of Fe and Mn were similar, because the binary oxide of Fe and Mn facilitated electron transfer from Mn(IV) to As(III), while the separation of Mn and Fe on MRGO–MnO₂ restricted the process. The optimal stoichiometry x for MRGO–FMBO (Mn_xFe_3-xO₄) was 0.46, and an extraordinary adsorption capacity of 24.38 mg/g for As(III) was achieved. MRGO–FMBO showed stable dispersive properties in aquifers, and exhibited excellent practicability and reusability, with a saturation magnetization of 7.6 emu/g and high conservation of magnetic properties after 5 cycles of regeneration and reuse. In addition, the presence of coexisting ions would not restrict the practical application of MRGO–FMBO in groundwater remediation. The redox reactions of As(III) and Mn(IV) on MRGO–FMBO were also described. The deprotonated aqueous As(III) on the surface of MRGO–FMBO transferred electrons to Mn(IV), and the formed As(V) oxyanions were bound to ferric oxide as inner-sphere complexes by coordinating their “–OH” groups with Mn(IV) oxides at the surface of MRGO–FMBO. This work could provide new insights into high-performance removal of As(III) in aquifers.     

象山港流域入湾河流水体中重金属风险评价及其来源解析

本文根据丰水期象山港8种溶解态重金属的浓度调查,通过单因子污染指数(P_i)、内梅罗综合污染指数(P_n)和重金属污染指数(HPI)评价方法研究了重金属流域内入湾河流中重金属的污染.基于流域内土地利用类型与重金属浓度的相关性,结合实地走访调查,对重金属的来源进行了解析.结果表明,区域内重金属平均浓度大小表现为:FeMnZnCuAsCrPbCd;除Mn和Fe外,其余6种重金属浓度均符合《地表水环境质量标准》中的Ⅰ类水标准;区域内重金属风险较低,无污染现象,但存在沾污情况;以水产养殖为代表的农业面源污染是区域内重金属出现沾污的主要因素.为了合理规避区域内城镇化发展进程中的重金属风险,重点在于加强以农业面源为主的污染源监管.     

Developing a sustainable operational management system using hybrid Shapley value and Multimoora method: case study petrochemical supply chain

Environment, Development and Sustainability - In this research, a new method to determine the supply chain performance based on its sustainable strategies is proposed. This method consists of a...     

Recycling of spent mushroom compost using earthworms Eisenia foetida and Eisenia andrei

A 90-day study conducted to explore the potential of epigeic earthworms Eisenia foetida and Eisenia andrei to transform the different types of agricultural wastes and spent mushroom compost into value-added product, i.e., vermicompost. Vermicomposting resulted in significant reduction in C:N ratio, pH, electrical conductivity, total organic carbon, TK; and increase in total Kajeldahl nitrogen, TP, and various micro and macronutrients compared to those in the worm feed. Our trials demonstrated that the vermicomposting could be considered as an alternate technology for recycling and environmentally safe disposal/management of the mushroom cultivation complexes’ residues mixed with different types of agricultural waste using epigeic earthworms E. foetida and E. andrei.     

Saving Energy and Reducing Emission When Recycling Acetone dudng the Production of Soy Phospholipid

Acetone,which is volatile,flammable,toxic,expen- sive and causing serious air pollution,is often used as extracting solvent in the production of powdery soy phospholipid.Recycling and reusing acetone is the key of reducing the cost of production. Therefore,saving energy and reducing emission when recycling acetone are the most important technologies during the production of phospholipid.On the basis of the productivity of powdery phospholipid being 2.4 t every day,43.2 t acetone is reused every 8 h and t...     

Manual Material Handling Assessment Among Workers of Iranian Casting Workshops

Manual material handling (MMH) tasks can be found in most workplaces and they may constitute a risk factor for work-related musculoskeletal disorders (WMSDs). This study was conducted to determine the prevalence of WMSDs and to compare MMH loads with the acceptable weight and force limits among Iranian casting workers. Data were collected from 50 workers of casting workshops who performed MMH tasks. The Nordic musculoskeletal disorders questionnaire and the Snook tables were used as tools for data collection. Hand/ wrist symptoms were the most prevalent problems among the workers (84%). The results of the Snook tables showed that the loads in lifting (84%), lowering (86%), carrying (66%), pushing with initial (43%) and sustained force (59%), and pulling tasks with initial (48%) and sustained force (93%) exceeded recommended limits. WMSDs occurred in high rates among the workers and, thus, ergonomics interventions should focus on decreasing WMSDs and redesigning MMH tasks.     

Assessment of food-energy-environmental pollution nexus in Iran: the nonlinear approach

Environmental Science and Pollution Research - Iran’s agricultural production has expanded significantly in recent years. Environmental pollution caused by the use of energy and chemical...     

Using artificial intelligence to make sustainable development decisions considering VUCA: a systematic literature review and bibliometric analysis

Environmental Science and Pollution Research - Sustainable development emergent subfields have been rapidly evolving, and their popularity increased in recent years. Sustainable development is a...