小城镇固体废弃物处理调查研究

我国小城镇固体废弃物污染问题日趋严重,从小城镇实际情况出发,提出切实可行的固体废弃物处理办法和技术是当务之急.本文采用典型调查的方式,对我国7个典型小城镇进行实地调查,总结出了我国小城镇固体废弃物的特点,固体废弃物处理现状以及固体废弃物处理方面的规划,指出了我国小城镇在固体废弃物处理方面存在的问题,并就如何改善小城镇固体废弃物处理提出了建议.调查结果为小城镇固体废弃物的处理办法和技术研究提供了依据.     

半刚性路面基层环境影响评价研究

采用输人输出模型,通过清单分析和归一化处理对我国典型的路面基层材料水泥稳定粒料与石灰稳定粒料以及几种工业固体废弃物路面基层材料的环境影响进行了研究并和水泥混凝土进行了对比.结果表明,工业固体废弃物路面基层对资源能源消耗量少,生产过程中固体废弃物、温室气体、酸雨气体的排放量小.和我国目前广泛使用的水泥稳定粒料相比,其环境影响较小,而且可以被再循环用作水泥生产的混合材,是一类典型的生态建筑材料.     

内循环流化床烟气脱硫装置结构及流化性能

提出了开发一种新型内循环流化床烟气脱硫装置的设想,通过不同型式床顶、床底结构的试验,确定了实现这一构想的最佳流化床结构型式;研究了冷态条件下该装置内床料流化的状态及固含率轴向分布情况,初步考察了其流体力学性质.实验结果表明,气速在2.5～5m/s时,装置能实现大量固体颗粒的内循环,床料在床内的运动呈"环-核"结构,床内固体颗粒物浓度高于传统等径流化床,可将其用于烟气脱硫工艺.     

Hazardous waste management in educational and research centers: a case study

The hazardous waste management (HWM) practice at Tehran University of Medical Sciences Central Campus, Iran, was investigated in this study. Four schools were selected and the required information such as type and amount of wastes, temporary storage methods, waste discharge frequency, and final waste disposal methods using sampling, questionnaires, interviews with laboratory staff, and reference to available documents were gathered. The quantity of hazardous waste generation per year excluding the uncontrolled wastewater was found to be 2.072 tons per year. The obtained results show that wastes having features of being infectious, toxic, ignitable, carcinogenic, corrosive, and reactive were present at 32%, 28%, 16%, 14%, 8%, and 2%, respectively. In the central campus, hazardous solid wastes managed with household solid wastes and hazardous liquid waste were discharged into the sinks without any kind of control; improper HWM practices are evident from the point of waste production to final disposal.     

Oxidized multiwalled carbon nanotubes modified with 2-(2-hydroxy-5-nitrophenyl)-4,5-diphenyl imidazole for solid phase extraction and preconcentration of some metal ions

In this work, a new procedure for the enrichment of the trace amount of Cu²⁺, Ni²⁺, Co²⁺, Pb²⁺, Fe²⁺, and Zn²⁺ ions based on the utilization of multiwalled carbon nanotubes (MWCNT) modified with 2-(2-hydroxy-5-nitrophenyl)-4,5-diphenyl imidazole as chelating agent prior to their determination by flame atomic absorption spectrometry has been described. The influence of effective parameters including pH, amount of ligand and MWCNT, composition of eluent, and coexisting ions on recoveries of understudy metal ions was examined. At the optimum pH of 5.0, all metal ions were quantitatively sorbed onto the proposed solid phase and completely desorbed with 8?mL of 5.0?mol?L^?1 HNO₃. The detection limit of Cu²⁺, Co²⁺, Ni²⁺, Pb²⁺, Fe²⁺, and Zn²⁺ ions was 1.7, 2.4, 2.3, 2.9, 2.8, and 1.4?µg?L^?1, while the preconcentration factor was 63 for Cu²⁺ and 94 for the other metal ions and relative standard deviations between 1.8 less than 3.0%. The proposed procedure was applied for the analysis of various samples.     

Determination of cadmium in water and herbal medicine by Penicillium chrysogenum immobilized on silica gel for flame atomic absorption spectroscopy

Penicillium chrysogenum was immobilized on silica to develop a simple and cost effective method for solid phase extraction of Cd(II) and determination using flame atomic absorption spectrometry (FAAS). The sorbent was characterized by Fourier transform infrared spectroscopy and packed into a column. The conditions for quantitative sorption and desorption of Cd(II) were optimized. The preconcentration factor was 100 while detection limit was 0.61 µg L^?1 with a relative standard deviation of 1.0%. The method was applied for determination of Cd in herbal medicine and tap water.     

Measurement of the leaching behaviour of granular solid wastes

Leaching of granular solids can be described in terms of specific mass transfer functions of a simple mathematical form.

The parameters can be determined by column leaching experiments under well known flow conditions.

Initially available concentrations are obtained from batch experiments at high dilution. Total concentrations in the solids are determined independently to calculate the available fractions.

The determination of the flow pattern is done by radiotracer measurements. Leachates are analyzed by various analytical methods including AAS and INAA. Total concentrations in the solids are determined by INAA preferably.     

Cleanup by solid‐phase extraction and HPLC of organochlorine insecticides and PCBS in various nonfatty and fatty samples

An accurate, simple and cheap extraction and cleanup procedure for capillary GC analysis of organo‐chlorine insecticides (OCs) in vegetables (cabbage and carrots) at the ng/g level, and for soil at the μg/g level is presented. The cleanup is carried out on solid‐phase extraction (SPE) cartridges, filled with 500 mg silica, 1 g of deactivated Florisil (10% w/w water), and 100 mg of anhydrous sodium sulphate. Recoveries >90% are obtained. The cleanup of OCs in fatty samples on an HPLC LiChrosorb Si 100 column is evaluated for subsequent capillary GC analysis. Fractionation of OCs and Aroclor 1254 and 1260 on an HPLC Nucleosil 100 column appears to be satisfactory.     

Evaluation of linear alkylbenzenesulfonate (LAS) biodegradability in sediment by solid‐phase extraction and HPLC analysis

The linear alkylbenzenesulfonate (LAS) sorption on environmental sediments has been known long ago. Their high concentrations reflect the massive input of these chemicals from household and industrial uses. However few attempts were made to identify biodegradation metabolites of LAS in sediment. In this report, a method for the determination of these compounds in sediment samples by high‐performance liquid chromatography (HPLC) is described. The first step of our work was performed by solid‐phase extraction with octadecyl‐bonded silica (C18) mini‐columns and provided a suitable recovery of LAS (90 ± 5%) and most metabolites. Furthermore, laboratory investigations led to study the behaviour of LAS in sediment. The environmental samples used for this purpose were collected from a pond (named étang de Bolmon) located in the French Mediterranean coast. Our results were in agreement with an aerobic biodegradation process of LAS that occurred only with high values of sediment redox potential and needed the samples to be vigorously shaken to ensure adequate mixing and suspension of particulate material. In a stagnant sediment or under anaerobic conditions, LAS is not degraded. p‐Sulfophenylacetic acid and p‐sulfocinnamic acid were evidenced as predominant metabolites and were found not to be persistent.     

Industrial ecology flows of agriculture and food industry in Finland: utilizing by-products and wastes

Although half of the administrative units in China are said to have implemented their local Agenda 21, the promotion of sustainable communities is not pervasive. In this paper, we adopted a relatively untried mode of analysis and a socio-economic context to illustrate the potentials and failures of China's grassroots local government bodies in achieving sustainable waste management. Our study shows that, among the three main functions of sustainable waste management (ensuring environmental hygiene, provision of recycling logistics and changing the consumption pattern of the local community) for local governments, grassroots local government bodies in mainland China are only able to do the minimum, i.e. ensuring environmental hygiene and handling complaints. One of the reasons for the failure is that, despite the emphasis on capacity building in China's Agenda 21, the reality is that no action is taken to empower grassroots local government. Despite the high profile accorded by the Chinese central government to motivating local governments to formulate their own Agenda 21, local sustainability and waste management performance have little relevance to the appraisal systems of these government agents.