一步法烟气浸锰-脱硫的工艺参数及机理

应用一步法烟气浸锰-脱硫的新工艺,考察烟气流量、烟气SO2浓度、吸收时间、液固比及浸出时间等工艺参数对烟气氧化脱硫效果的影响,并运用溶液化学原理,对SO2及Mn2 在溶液中的组分进行了计算,研究Mn2 液相催化氧化烟气脱硫的机理.在吸收液pH值5-6时,锰主要以Mn2 形态存在,Mn2 的存在强化了从HSO-3开始发生的SO2氧化反应.采用菱锰矿为原料,能有效地脱除含SO2烟气中的硫,在实现烟气脱硫的同时自动调节溶液的pH值,并可从浸出液中回收高价值的硫酸锰.在最佳的工艺条件下,仅一步吸收过程,取得了锰浸出率85%,含SO2烟气脱硫率70%以上的效果.     

基于因子-聚类分析的地下水中阳离子来源研究

于2020—2021年对某市20个监测井80份地下水样本进行了调查。采用因子分析和聚类分析法以地下水中阳离子浓度为研究对象进行溯源分析。结果表明,地下水中阳离子浓度会受到不同程度、不同类别的人类活动影响,其阳离子的来源呈现多样化的特点,其中铅、铜、铝、锰为农业面源来源,铵、钠、总硬度是工业来源,另外,砷、铁及锌等为自然来源,而在自然来源中出现的砷、铁阳离子的富集现象,很明显是受到了城镇化及工业化的影响。锌与氢离子可能是地下水中pH值受到人类活动的影响,或者是地表水的侧向补给带来的影响。     

Leaching behavior of Pb and Zn in air pollution control residues and their modeling prediction

Increasing attention has been paid to air pollution control （APC） residues in China recently due to the rising proportion of waste incineration and the hazardous characteristics of the residues, among which heavy metal leaching toxicity plays an important role. Leaching behavior and potential risk of Pb and Zn in the APC residues from a Shanghai municipal solid waste （MSW） incinerator was studied, based on the leaching tests under different conditions and theoretical calculation using a geochemical thermodynamic equilibrium model MINTEQA2. Results showed that, extractant species and liquid to solid （L/S） ratio predominantly controlled the leaching toxicity of Pb and Zn, while ionic strength, vibration method and leaching time had less effect on the metals release. Leachate/final pH determined the metal leaching behavior, which changed the speciation of heavy metals in the extraction system. The equilibrium aqueous speciation, precipitation-dissolution of Pb and Zn was investigated according to the model computation, which was well in agreement with the experimental results.     

苎麻脱胶废水喷淋锅炉烟气除尘脱硫降碱的实验研究

利用苎麻脱胶碱性废水喷淋锅炉烟气,可降低烟气中的粉尘、SO₂;采用中和碱性废水可节省原水膜除尘所耗的自来水。结果表明,碱性废水喷淋烟气对SO₂的脱除率是自来水喷淋效果的40倍,粉尘去除率高于自来水喷淋的33％,COD下降18％。为造纸、制药、印染等企业提供了碱性废水前处理新工艺。     

多批次生物沥浸对猪粪重金属脱除及养分和脱水性的影响

猪粪重金属脱除及脱水性提升对其资源化利用具有重要意义.本研究以氧化亚铁硫杆菌(Acidithiobacillus ferrooxidans,A.f)作为生物沥浸微生物,探究了多批次生物沥浸对猪粪重金属脱除及养分和脱水性的影响.研究表明,当A.f菌液与原始猪粪(含固率为3.5％)体积比为1∶1时,生物沥浸进程缓慢,而将猪...     

酸性淋溶对铅锌尾矿金属行为的影响及植物毒性

露天存放的铅锌尾矿受到自身酸化和酸雨的双重影响,从而加剧尾矿对环境的影响。因此,研究尾矿在酸性条件下的重金属行为及其植物毒性,对植物在铅锌尾矿地的自然定居有非常重要的意义。将铅锌尾矿砂装柱,用pH2～7溶液淋溶50天的结果表明,酸度的提高可以显著地增加尾矿砂中重金属（Pb、Zn、Cu和Cd）的溶出。而随着时间的延长,Zn的溶出量明显增高,Pb和Cu的溶出则逐渐降低。在pH值＜3时,Cd的溶出逐渐升高,pH值＞3时,Cd的溶出也呈下降趋势。酸度对重金属溶出的影响由大至小依次为Zn＞Cd＞Cu＞Pb。渗滤液对植物的毒性随着起始淋溶酸度的提高与时间的推移而加剧     

The Impact of Scrubber Sludge on Ground Water Quality at an Abandoned Mine Site

A sulfate-rich flue gas desulfurization scrubber sludge was used as a substitute backfill material in reclamation of an abandoned coal strip mine. The site was surrounded by monitor wells and the material was characterized for leaching behavior using open column experiments. A drain was placed directly beneath the 45 000 ton fill to enable sampling before dilution or attenuation. The column studies indicated that the scrubber sludge would adsorb manganese, iron, aluminium, cobalt, nickel, thallium and zinc contaminants from the water. Changes in pH appear inadequate to explain the removal by precipitation. The groundwater cleaning phenomenon has been confirmed on a field scale by the drain samples. Boron and molybdenum leach from the fly ash was used to fix the scrubber sludge and serve as marker elements enabling calibration of the dispersivity in computer models of the groundwater system at the site. The leachate front appears to be diluted by a factor of 8 : 1 within the first 15 meters. Since boron and molybdenum release are associated only with the first flush, environmental impacts will be minimal. Columns appear to create a time compression effect on the duration of leaching phenomenon. The effect for this site appears to be at least 5 : 1. The columns were effective in predicting which elements would leach or adsorb in the field and in predicting the actual source concentrations. Other shake tests such as the TCLP and the ASTM shake test were found to be less effective at predicting which elements would leach and were not helpful in predicting field concentrations.     

全自动淋洗-智能蒸馏联合技术检测土壤中阳离子交换量

针对土壤中阳离子交换量检测国标方法的不足,介绍了一种全自动淋洗法结合自动智能一体化蒸馏的联合技术。通过对实际样品和6种土壤标样的比较实验,表明,淋洗时间设置为20 min、乙醇洗涤次数设置为4次、蒸馏液质量设置为130 g较佳,在该条件下,土壤标样及实际样品的相对标准偏差(0.87%~1.07%)远小于行业标准方法的标准偏差(3.87%~5.18%),方法准确度也均在保证值范围内。该方法自动化程度高、可操作性强且检测结果的准确度、精密度及重现性都符合标准规定,可满足大批量土壤样品分析要求。     

Leaching and sorption of neonicotinoid insecticides and fungicides from seed coatings

Seed coatings are a treatment used on a variety of crops to improve production and offer protection against pests and fungal outbreaks. The leaching of the active ingredients associated with the seed coatings and the sorption to soil was evaluated under laboratory conditions using commercially available corn and soybean seeds to study the fate and transport of these pesticides under controlled conditions. The active ingredients (AI) included one neonicotinoid insecticide (thiamethoxam) and five fungicides (azoxystrobin, fludioxonil, metalaxyl, sedaxane thiabendazole). An aqueous leaching experiment was conducted with treated corn and soybean seeds. Leaching potential was a function of solubility and seed type. The leaching of fludioxonil, was dependent on seed type with a shorter time to equilibrium on the corn compared to the soybean seeds. Sorption experiments with the treated seeds and a solution of the AIs were conducted using three different soil types. Sorption behavior was a function of soil organic matter as well as seed type. For most AIs, a negative relationship was observed between the aqueous concentration and the log K_oc. Sorption to all soils tested was limited for the hydrophilic pesticides thiamethoxam and metalaxyl. However, partitioning for the more hydrophobic fungicides was dependent on both seed type and soil properties. The mobility of fludioxonil in the sorption experiment varied by seed type indicating that the adjuvants associated with the seed coating could potentially play a role in the environmental fate of fludioxonil. This is the first study to assess, under laboratory conditions, the fate of pesticides associated with seed coatings using commercially available treated seeds. This information can be used to understand how alterations in agricultural practices (e.g., increasing use of seed treatments) can impact the exposure (concentration and duration) and potential effects of these chemicals to aquatic and terrestrial organisms.     

污泥厌氧消化液中碳酸盐对回收磷的影响

为探讨污泥厌氧消化液中碳酸盐对以磷酸钙盐形式回收磷的影响,以粉煤灰浸出液为钙源,考察了消化液中的碳酸盐对磷回收过程和磷回收产物性质的影响。实验结果表明,在反应pH为10、反应钙磷摩尔比为1.67、反应时间为10 m in的条件下,消化液碳酸盐浓度为2 400 mg/L(以CaCO3计)时,磷的回收率为78.53%,回收产物中磷含量(以P2O5计)为28.93%;对消化液进行盐酸预酸化使pH达到4及以下时,磷回收率接近100%,回收产物中磷含量(以P2O5计)达到43.08%。消化液中碳酸盐的存在易形成碳酸钙沉淀,从而降低了磷回收率、回收产物中磷含量以及回收产品的纯度;预酸化能够有效地去除消化液中的碳酸盐并降低了其对磷回收的不利影响。