沸石在废水处理中的应用研究进展

摘要：沸石资源分布广泛、储量大,廉价易得,而且可以通过再生重复利用。沸石结构上的独特性和资源上的分布优势及其可循环利用的特点使其已成为废水处理工艺中常用的水处理剂之一,沸石具有物理吸附和离子交换特性,广泛应用于废水中氨氮、重金属、有机物和放射性物质的去除,是常用水处理剂之一。本文就其在水处理方面的应用、吸附机理、改性方法及再生方法的国内外研究进展进行了综述、分析,对沸石今后的研究工作进行了展望。     

环保型吸水膨胀聚合物凝胶的合成与评价

吸水性聚合物用于三次采油的机理是依靠这种聚合物在高含水层孔道表面产生的吸附机理与在孔道中形成的动力捕集和物理堵塞作用,在水的浸泡下,吸水性聚合物形成凝胶膨胀体,对大孔道实行封堵,起到调整吸水剖面,提高驱油效率的目的。以丙烯酸(AA)、丙烯酰胺(AM)为原料合成高吸水性聚合物凝胶,研究合成条件对聚合物凝胶吸水性能的影响,确定最佳合成条件为:当丙烯酸含量达到总量的80%左右,交联剂用量占单体总固含量的0.4%、引发剂用量占单体总固含量的0.4%、pH为5~11。实验结果表明:该聚合物凝胶适用于高含水油田调剖堵水,且可以重复使用,对储层无伤害。     

Phytoremediation potential of indigenous plants from Thai Nguyen province, Vietnam

This study was focused on determining Arsenic (As), Lead (Pb), Cadmium (Cd) and Zinc (Zn) in 33 indigenous plants and 12 soil in-situ plant samples in Thai Nguyen Province, Vietnam. The results showed that the soils of surveyed mining areas contained 181.2- 6754.3 mg kg(-1) As, 235.5-4337.2 mg kg(-1) Pb, 0.8- 419 mg kg(-1) Cd and 361.8-17565.1 mg kg(-1) Zn depending on the characteristics of each mining site. These values are much higher than those typical for normal soil. The heavy metal uptake into shoots and roots of 33 indigenous plant species was also determined. Two species of the plants investigated, Pteris vittata L. and Pityrogramma calomelanos L. were As hyperaccumulators, containing more than 0.1% heavy metals in their shoots. Eleusine indica L., Cynodon dactylon L., Cyperus rotundus L. and Equisetum ramosissimum (Vauch) accumulate very high Pb (0.15-0.65%) and Zn (0.22-1.56%) concentration in their roots. Additional experiments to clarify the potential of six these plants as good candidates for phytoremediation of heavy metal pollution soil are being carried out in our laboratory.     

Soils and sediments of the Thua Thien-Hue Province (central Vietnam): recognizing trace element sources and the likely influence of natural events

Trace element concentrations have been measured in soil and sediment samples taken from the Thua Thien Hue (TT-H) Province and the Tam Giang-Cau Hai (TG-CH) Lagoon in 2002 and 2004. Results show that the lagoon is only slightly contaminated by elements such as Ag, Cd, Cr, Cu, Ni, Pb and Zn, whereas As, probably naturally enriched in this Asian region, reaches values above the lowest internationally accepted sediment quality guidelines. Concentrations in soils are ascribable to natural sources and distributions in the TG-CH Lagoon are mainly influenced by river inputs, with Ag and Cd undergoing estuarine desorption processes. However, concentration-depth profiles of most trace elements in sediments show a recent increasing trend that might be linked to the economic development of the area. The comparison of porosity and (210)Pb depth profiles (confirmed also by Cd and As) from repeated samplings of the same core locations in the TG-CH Lagoon seems to account for a loss of 5-10 cm of surficial sediment that took place during the time interval between the two samplings. It is hypothesized that extreme meteorological events (e.g. a major typhoon that hit the area in November 2003) could be responsible for such sediment displacement.     

Antibiotic and antiparasitic residues in surface water of urban rivers in the Red River Delta (Hanoi,Vietnam): concentrations,profiles, source estimation,and risk assessment

Environmental Science and Pollution Research - Antibiotic residues and antimicrobial resistance in surface water are issues of global concern, especially in developing countries. In this study, the...     

Insights of healthcare waste management practices in Vietnam

Environmental Science and Pollution Research - Nowadays, together with the economic development, public health activities have gained substantial attention with increasing number of hospitals...     

Enhanced degradation of reactive brilliant red X-3B by photocatalysis integrated with micro-electrolysis

Environmental Science and Pollution Research - The microwave electrodeless lamp UV photocatalysis (MWUV) integrated with iron carbon micro-electrolysis (ME) was applied to degrade reactive...     

SSF净化技术处理含油污水

SSF净化(suspended sludge filtration)是一种新兴的污水处理技术,其在处理量为1.8×104m3/d大型污水处理站的首次应用中,取得了较好的效果,可达到ρ(油)≤10 mg/L、ρ(SS)≤15 mg/L的指标,克服了常规流程二次沉降罐沉降分离效果差、处理效率低等问题。SSF净化装置投加混凝剂65.00 mg/L、助凝剂0.84 mg/L,药剂成本约0.31元/m3。该工艺流程短、运行成本低、投资省,适用于来水水量水质相对稳定的污水处理站。     

Effects of eggshell addition on calcium-deficient acid soils contaminated with heavy metals

The eggshell was used to remediate the contaminated soil by heavy metals. The eggshell addition decreased the available state of the heavy metals. The available calcium in the soil increased due to eggshell addition. The efficiency was investigated in different moisture conditions. In this study, effects of water conditions (flooded, wet, or dry) and eggshell dosages (0, 0.1, 1.0, and 10.0 g/kg soil, respectively) on pH variation, content of unavailable state of heavy metals, form of heavy metals, and available nutritious element calcium (Ca) in acid soils contaminated with heavy metals were investigated, respectively. The soil samples were continuously cultivated indoors and analyzed by toxicity characteristic leaching procedure and community bureau of reference (BCR) sequential extraction procedure. The results showed that the addition of eggshell could effectively improve the pH of acid soil and increase it to neutral level. Moreover, the contents of unavailable state of heavy metals Cu, Zn, and Cd increased significantly. Furthermore, when the soil was cultivated under the flooded condition with 1.0 g/kg eggshell, the unavailable state of Cu, Zn, and Cd increased the most, and these heavy metals were transformed into residual state. On the other hand, the amount of available state of Ca increased to 432.19 from 73.34 mg/kg with the addition of 1.0 g/kg eggshell, which indicated that the addition of eggshell dramatically improved the available state of Ca. Therefore, eggshell could ameliorate the soil environment as it led to the decrease of available heavy metals and improvement of fertilization effectively. In a word, this study indicates that the addition of eggshell would be a new potential method for remediation of acid field soils contaminated with heavy metals.     

Toxicity screening of biodegradable polymers. I. Selection and evaluation of cell culture test methods

A screening test method for potential toxicity of biodegradable plastics on humans and the environment was selected and evaluated with samples of cellulose acetate, Bionolle, polyhydroxybutyrate-co-valerate (Biopol), and polycaprolactone (Tone polymer). Among the standardin vitro tests using animal cell cultures for the evaluation of biomedical materials, the test by direct contact and the test with extract were examined. Qualitative and quantitative determinations of the cell viability and morphology indicate that the test with extracts can be easily performed, providing reproducible and comparable results for all materials. Using the cell culture test with the extract of sterile samples, an estimation of the toxicity of a new polymeric material can be obtained within a few weeks.