Transfer of metals from soil to vegetables in an area near a smelter in Nanning, China

A field survey was conducted to investigate the metal contamination in soils and vegetables, and to evaluate the possible health risks to local population through foodchain transfer near a smelter in Nanning, southern China. Contamination levels in soils and vegetables with cadmium (Cd), lead (Pb), zinc (Zn) and copper (Cu) were measured, and transfer factors (TF) from soils to vegetable plants and its health risk (risk index, RI) were calculated accordingly. Results showed that both soils and vegetables from villages 1 and 2 (V1 and V2, 1500 m and 500 m from the smelter) were heavily contaminated, compared to a village 50 km from the smelter. Geometric mean of Cd and Pb concentrations in vegetables for V1 and V2, respectively, were 0.15 and 0.24 mg Cd kg(-1) and 0.45 and 0.38 mg Pb kg(-1) (on fresh weight basis). Oral intake of Cd and Pb through vegetables poses high health risk to local residents. Risk indices for V1 and V2, respectively, were 3.87 and 7.42 for Cd, and 1.44 and 13.5 for Pb. The complexity of metal contamination and their health risks are also discussed.     

长沙市夏季大气颗粒物中重金属的形态及其源解析

对长沙市高开区、经开区、开福区以及马坡岭4个采样点夏季的大气颗粒物(TSP)浓度以及颗粒物中的重金属元素Cu、Zn、Mn、Pb和Cd的浓度和形态分布进行了研究分析,利用污染因子(Cf)对重金属元素的可保持能力进行了评价,并利用因子分析方法(PCA)分析TSP中重金属元素的主要来源。结果显示长沙市夏季TSP平均浓度为220.7μg/m3,表明长沙市颗粒物污染较严重。TSP中重金属元素浓度大小顺序为:ZnPbCuMnCd。从形态分布来看,大约63.3%~89.0%的Cu主要存在于可氧化态(F3),而Mn在这一态中分布最少。元素Zn、Cd则主要分布在弱酸提取态,分别占了70%和35%。Pb主要分布在残渣态,大约为24%~43%。由污染因子计算可知Cu、Cd和Zn比Mn、Pb有更高的迁移性。     

Experimental study on the control of black smoke pollution from the ceramic kilns based on the mechanism of the surfactant and coagulant

Aiming at the characteristics of carbon black, a new method of controlling the black smoke from the industrial coal-burning ceramic kilns by wetting was brought forward. The carbon black in the flue of coal-burning ceramic kiln was collected for the experiments, and its physical and chemical properties were studied in detail. In order to change the sedimentation and wettability state of the carbon black, the complex solution of the coagulant and surfactant was applied. After a series of orthogonal experiments, the complex solutions with better effects were chosen. Then, the sedimentation percentage of carbon black treated by the selected complex solutions was measured. The optimized complex solutions included Na₂SO₄ (100 mmol/L), sodium dodecyl benzenesulfonate (SDBS) (1.2 mmol/L) and polyacrylamide (PAM) (40 mg/L). After carbon black was absorbed, the complex solutions were clear and colorless. The complex solutions can be recycled, and the sedimentation percentage of carbon black is 94%.     

Status and changes of water quality in typical near-city zones of three East African Great Lakes in Tanzania

Environmental Science and Pollution Research - Tanzania is the only country bordering all three transboundary East African Great Lakes, i.e., Lake Victoria, Lake Tanganyika, and Lake Nyasa (Lake...     

An investigation on the promoting effect of Pr modification on SO2 resistance over MnOx catalysts for selective reduction of NO with NH3

Environmental Science and Pollution Research - Pr-modified MnOx catalyst was synthesized through a facile co-precipitation process, and the results showed that MnPrOx catalyst exhibited much better...     

The effect and its critical window for ambient temperature and humidity in pregnancy on term low birth weight

Environmental Science and Pollution Research - As common meteorological factors in daily life, there is limited evidence for the effect of ambient temperature and humidity during pregnancy on the...     

Effect of Brown-Rotted Spruce as Lignin-Enriched Filler on the Properties of Reinforced Polyurethane Foam

Journal of Polymers and the Environment - The study investigated the effect of lignocellulosic biomass filler decayed by brown-rot fungi on the preparation and properties of polyurethane (PU) foam....     

Air pollution and urban road transport: evidence from the world’s largest low-emission zone in London

Environmental Economics and Policy Studies - Low-emission zones (LEZs) have been implemented widely in Europe to tackle air pollution sourced from vehicular emissions. We quantify the effectiveness...     

基于微生物新陈代谢过程的污泥原位减量技术进展

解决剩余污泥问题的关键是将污泥原位减量技术(过程处理)与剩余污泥处理处置技术(末端处理)相结合,对污泥实施联合处理。污泥原位减量技术是在保证出水达标的前提下,尽量促进微生物降解有机物产能用于热逸散而非增殖的一种污水处理技术,其(非生物捕食)主要通过溶胞-隐性生长、解耦联代谢和维持代谢等方式影响污泥中微生物的增殖、衰亡和水解,进而降低剩余污泥产量。为系统了解当前污泥减量技术的驱动机制及关键问题,在分析污泥增殖和微生物新陈代谢途径的基础上,梳理了减量技术对微生物生长(电子受体、代谢解偶联及维持能)、衰减(饥饿、噬菌体、温度、辐射、极端环境及生物抗性)及水解(水解及水解强化)的影响机制及内部驱动,明确了基于微生物代谢过程的减量技术的不足及其对污水处理效果的影响;在总结各类原位减量技术利弊的基础上,展望了污泥原位减量技术的应用前景。     

WILLINGNESS TO PAY FOR FLOOD RISK REDUCTION AND ITS DETERMINANTS IN JAPAN1

ABSTRACT: This study aimed to clarify public preferences for flood control measures in Japan, willingness to pay (WTP), and the main factors involved in WTP by applying the contingent valuation method. Findings showed that most residents surveyed expected some flood control measures, and revealed a diversity of interest in river management. WTP levels for different measures ranged from a mean of ¥2,887 to ¥4,861 and from a median of ¥1,000 to ¥2,000. However, WTP for additional flood risk reduction beyond initial levels was found to be zero. This was considered to be because WTP for flood risk reduction must be determined within a multi‐risk context. WTP for flood control measures may increase with per capita income, individual preparedness, and/or experience with flooding, but may decrease with distance from a river, acceptability of flood risk, and provision of environmental information. Furthermore, perception of flood risk may increase WTP, while perception of other risks may decrease it. Methods of dealing with environmental risk that were proposed in the survey may have affected WTP levels.