Uptake of PAHs by cabbage root and leaf in vegetable plots near a large coking manufacturer and associations with PAHs in cabbage core

Samples of ambient air (including gaseous and particulate phases), dust fall, surface soil, rhizosphere soil, core (edible part), outer leaf, and root of cabbage from eight vegetable plots near a large coking manufacturer were collected during the harvest period. Concentrations, compositions, and distributions of parent PAHs in different samples were determined. Our results indicated that most of the parent PAHs in air occurred in the gaseous phase, dominated by low molecular weight (LMW) species with two to three rings. Specific isomeric ratios and principal component analysis were employed to preliminarily identify the local sources of parent PAHs emitted. The main emission sources of parent PAHs could be apportioned as a mixture of coal combustion, coking production, and traffic tailing gas. PAH components with two to four rings were prevailing in dust fall, surface soil, and rhizosphere soil. Concentrations of PAHs in surface soil exhibited a significant positive correlation with topsoil TOC fractions. Compositional profiles in outer leaf and core of cabbage, dominated by LMW species, were similar to those in the local air. Overall, the order of parent PAH concentration in cabbage was outer leaf > root > core. Partial correlation analysis and multivariate linear stepwise regression revealed that PAH concentrations in cabbage core were closely associated with PAHs present both in root and in outer leaf, namely, affected by adsorption, then absorption, and translocation of PAHs from rhizosphere soil and ambient air, respectively.     

Effect of surfactants at low concentrations on the sorption of atrazine by natural sediment.

A series of experiments were carried out to determine the effect of surfactants at low concentrations on the sorption of atrazine by natural sediments. With surfactant concentrations ranging from 0 to 20 mg/ L, anionic and cationic surfactants appreciably reduce the adsorption of atrazine, while nonionic surfactant decreases the adsorption of atrazine at concentrations equal to or less than 1 mg/L and increases adsorption at higher concentrations. Desorption of atrazine in the presence of different sodium dodecylbenzene sulfonate (SDBS) concentrations shows that a portion of the bound pesticide resists desorption in the SDBS free system. However, the addition of SDBS accelerates the desorption of atrazine. Furthermore, the nature of sediment and the contacting sequence of SDBS, at 10 mg/L, with the sediment, also influence the adsorption of atrazine. The conclusions in this study could be explained partially by the effect of the type and concentration of surfactants and the characteristics of sediments.     

贵州草海湿地农田渠系水质空间分异特征及影响分析

为了解草海湿地农田渠系水质现状、空间分异特征及影响因素,于2011年秋季对草海湿地进行大空间尺度的采样,分析了氮磷等理化指标,采用单因子污染指数法和营养状态指数法分别对农田渠系水质和湖泊营养状态进行评价.结果表明,草海湿地农田渠系水质污染严重,多数水质为V类或劣V类,总氮和溶解氧是水体中的主要污染因子;上游水质劣于下游,尤其是上游靠近县城区域的水质最差;多等级排水渠系对氮磷具有一定的截留作用,干渠V级水质好于低级渠系水质;不同的土地利用方式对水质的影响不同,城镇用地>集中式村落>农田;草海湿地水体上、中、下游营养水平分别为中度富营养、轻度富营养和中营养,外源污染物的累积和湖泊营养水平的提高导致其沼泽化,而流域不合理的土地利用结构加剧了沼泽化的进程.     

纳米级铁粉脱氯降解四氯化碳

四氯化碳的生产和使用，给人类带来了较大危害。为此，采用纳米铁粉这一新方法对其进行脱氯处理。试验以纳米级铁粉对四氯化碳的脱氯率为考察指标，选用L25（5^6）正交试验方案，考察了降解介质的初始pH值、纳米铁粉的质量、降解温度、摇床转速和脱氯时间5个影响因素。结果表明，pH值这一因素有极显著影响；在得出的纳米铁粉对四氯化碳脱氯的最佳工艺条件下，获得了99．5％的脱氯率，为有机氯化物脱氯开辟了一条新途径。     

可交易水污染许可证发展现状与应用前景

可交易排污许可证在传统的排污许可证基础上，引入市场机制。不但对企业选择污染控制手段赋予更大的灵活性，而且可以大大节约水污染控制费用、剌激企业开发并建设更加经济有效的污染控制技术。国外十多年的研究和实践证明可交易排污许可证是一种经济而有效的环境管理手段。水污染排放许可证制度在我国的应用已有一定基础。在条件具备的地区可以引进可交易水污染物排放许可证制度，本文回顾了“可交易水污染许可证制度”的理论分析和国外实践，进而探讨在中国的应用前景     

植物对Cd-B[α]P复合污染土壤的修复

为了研究植物对Cd-B[α]P复合污染土壤的修复效果,本研究采取实验室模拟实验的方法,通过种植黑麦草、芥菜、苜蓿和高羊茅,进行Cd、B[α]P污染土壤修复植物的筛选。结果表明,芥菜和黑麦草对土壤中有效态Cd均有富集能力。黑麦草对B[α]P污染土壤修复效果比苜蓿、高羊茅的修复效果强,75 d时,平均富集系数最高为1.1。在Cd-B[α]P复合污染土壤植物修复效果的研究中,选择在土壤中种植黑麦草,结果表明,黑麦草对Cd-B[α]P复合污染土壤中Cd和B[α]P 有良好地去除作用,75 d时,分别达到58.55%和89.95%。     

Synthesis of cellulose-fatty acid esters for use as biodegradable plastics

Long-chain fatty acid carbohydrate esters (FACE) were synthesized by the acid chloride-pyridine reaction to different degrees of substitution (DS). The hydrolyzed soybean oil was used as the source of unsaturated fatty acids. High molecular weight FACE polymers are insoluble in common solvents, such as benzene, toluene, THF, etc., and are highly water resistant. However, FACE polymers of hydrolyzed cellulose (MW 180 kD) are soluble/swellable in toluene and can be cast into tough, flexible films. FACE polymer properties of tensile strength and clasticity vary with degree of substitution and polymer size.Paper presented at the Bio/Environmentally Degradable Polymer Society—Third National Meeting, June 6–8, 1994, Boston, Massachusetts.     

煤矿综采放顶煤工作面高浓度粉尘的综合防治

煤矿综采放顶煤工作面开采强度大、产尘尘源多、粉尘浓度高,因而对尘毒的治理难度大。为此,提出了治理的总体思路、防治方案并在几十个煤矿综采放顶煤工作面推广,取得了很好的效果。     

粗铜酞菁颜料生产中的三废治理

粗铜酞菁生产尾气中的氨可用硫酸吸收制硫酸铵,粉尘可用捕集器回收,废水采用物化与生化相结合的治理工艺,效果好,投资少,运行费用低,并可回收铜。     

The role of condensed organic matter in the nonlinear sorption of hydrophobic organic contaminants by a peat and sediments

This study examines the effect of soil organic matter heterogeneity on equilibrium sorption and desorption of phenanthrene, naphthalene, 1,3,5-trichlorobenzene (1,3,5-TCB), and 1,2-dichlorobenzene (1,2-DCB) by soils and sediments. Two estuary sediments, a Pahokee peat (PP; Euic, hyperthermic Lithic Haplosaprist), and two subsamples (base- and acid-treated peat [TP] and acid-treated peat [FP]) of the peat were used as the sorbents. The contents of black carbon particles were quantified with a chemical extraction method. Petrographical examinations revealed the presence of the condensed soil and sediment organic matter (SOM) in Pahokee peat. The Freundlich isotherm model in two different forms was used to fit both sorption and desorption data. The results show that the sorption and desorption isotherms are generally nonlinear and that the apparent sorption-desorption hysteresis is present for phenanthrene and TCB. Detailed analysis of sorption data for the tested sorbent-sorbate systems indicates that black carbon is probably responsible for sorption isotherm nonlinearity for the two sediments, whereas the humic substances and kerogen may play the dominant role in nonlinear sorption by the peat. This investigation suggests that the microporosity of SOM is important for the hydrophobic organic contaminant (HOC) sorption capacity on the peat.