基于高铁酸钾同步氧化-絮凝技术在污水处理中的研究进展

Fe(Ⅵ)具有较高的氧化还原电位,Fe(OH)3具有良好的絮凝效果,废水处理中高铁酸钾发挥同步氧化和絮凝作用。介绍高铁酸钾处理各种难降解废水的机理,同时分析高铁酸钾投加量、pH、反应温度、反应时间等因素对各种废水去除效果的影响。并提出基于高铁酸钾同步氧化絮凝技术处理污水的局限性和未来的发展方向。     

重金属离子与依诺沙星相互作用的荧光光谱法研究

荧光分析法是利用物质的荧光性质对物质进行分析的方法,文章应用荧光法研究了不同温度下重金属离子Cu2+、Pb2+及Mn2+与喹诺酮类药物依诺沙星(ENX)的相互作用。结果表明:Cu2+、Pb2+及Mn2+对ENX内源荧光的猝灭机制属于形成复合物所引起的静态猝灭,利用Stern-Volmer关系式计算了ENX与重金属离子Cu2+、Pb2+及Mn2+之间的猝灭常数KSV及结合位点数,根据热力学参数(自由能变ΔG、焓变ΔH、熵变ΔS)确定了ENX与重金属离子之间的主要作用力类型为静电作用力。该研究为探讨环境中重金属离子与ENX的作用机理和环境效应提供了理论依据。     

氨基硫脲改性山竹壳对Cd2+. Pb2+的吸附

采用氨基硫脲改性山竹壳,制备新型的改性山竹壳吸附剂,研究其对Cd2+、Pb2+的吸附性能。结果表明,吸附Cd2+、Pb2+的适宜条件为:pH 6.0,吸附时间120 min。改性后山竹吸附剂对Cd2+、Pb2+的吸附容量能有了很大程度的提高,Cd2+、Pb2+最大吸附量分别达到39.37、57.14mg/g。吸附过程可以很好地用准二级动力学方程描述,吸附等温线用Langmuir方程的拟合效果优于Freundlich方程。     

基于Kriging插值的路旁土壤重金属含量空间分布 ——以310国道郑州-开封段为例

分别在G310国道郑州-开封段的杏花营路段两侧150m×150m范围内布设7条垂直于公路的采样子断面,从路肩向两侧每隔10m采集1个表土混合样,共采集226个样品（包括2个对照样品）.用ICP-MS测定了土壤重金属（Pb、Cu、Zn、Cd、Cr和Ni）含量,并用Universal Kriging插值法分析路旁土壤重金属空间分布特征.结果表明,路旁土壤重金属呈与道路平行的带状分布,表明6种重金属含量均受公路交通影响,属于公路源重金属.土壤Cr和Cu含量在路基处含量最高,向两侧逐渐下降,呈指数分布;土壤Pb、Zn、Cd和Ni含量在距路基30～50m处出现峰值,呈偏态分布.路旁土壤Pb、Cu、Zn、Cd、Cr和Ni均为交通源重金属.     

象山港养殖区缢蛏和泥蚶的Cu、Cd、Pb含量及其健康风险评价

根据2010年全年4个季节象山港5个养殖区(大佳何、郭巨、咸祥、桐照、西店)两种贝类(缢蛏、泥蚶)体中的3种重金属(Cu、Cd、Pb)的检测结果,分析和比较了象山港内贝类体中的重金属含量,并应用两种评价模型进行了健康风险评价.结果为:所测得Cu、Pb、Cd在5个不同的养殖区的缢蛏和泥蚶体中的含量分别在2.89～4.99、0.24～0.39、0.12～0.22mg.kg-1和0.79～1.05、0.10～0.38、2.17～4.60mg.kg-1范围,其中大佳何的缢蛏体内的Cu、Pb含量要高于其他4个养殖区,郭巨的泥蚶体内的Cd含量高于其他4个区;其次,同一种重金属Cu、Pb、Cd在两种贝类中的含量分别为1.52～10.48和0.66～1.20mg.kg-1,0.08～0.68和0.02～1.01mg.kg-1,及0.04～0.50和0.74～4.43mg.kg-1范围,Cu在缢蛏体中的含量远远大于泥蚶,而Cd在泥蚶中的含量远远大于缢蛏;所得结论为:不同养殖区内,同一种重金属在同种贝类体内的含量存在明显的差异;同一种重金属在不同种类贝类中的含量也存在明显的差异;贝类的不同养殖规格及不同年龄间Cu、Pb、Cd的含量基本相同,无明显差异;采用USEPA和PMTDI两种健康风险评价模型得出相同的结果:除泥蚶体中Cd可能存在致癌健康风险外,其他对人体均不存在健康风险.     

三种磺酰脲类除草剂在土壤中的降解及吸附特性

采用室内模拟试验方法,研究了氟胺磺隆、氯吡嘧磺隆和磺酰磺隆3种磺酰脲类除草剂在5种不同种类土壤(江西红壤、太湖水稻土、东北黑土、南京黄棕壤、陕西潮土)中的降解及吸附特性.结果表明,这3种磺酰脲类除草剂在这5种不同土壤中的降解速率均比较快,且降解过程均遵循一级动力学方程,土壤pH值是影响土壤降解速率的主要因素.3种磺酰脲类除草剂在土壤中的吸附均符合Frendlich模型,且具有较低的吸附容量.3种磺酰脲类除草剂在不同土壤中的吸附自由能变化均小于40kJ.mol-1,吸附主要以物理吸附为主,吸附常数随土壤pH值的增大而逐渐减小.     

垃圾焚烧灰性质分析及控制方法

随着焚烧技术在垃圾处理方式中普遍采用,焚烧产生的灰渣数量也日益增加。灰渣与飞灰中有毒的重金属及有机物质会污染土壤与地下水,对人类健康造成极大的影响。本文对各类垃圾焚烧灰渣的物理化学性质及重金属浸出特性进行了详细的阐述,介绍了灰渣的毒性分析与控制方法。通过分析可知:为了避免灰渣二次污染应该重点控制铬、镉、铍、铅等重金属和二恶英、呋喃等有机物的污染;处置后的灰渣有害离子浸出能力降低,根据灰渣物理和工程性质,可以成为再生资源充当填充材料和混凝土与沥青路面骨料等。     

Heavy metal phytoextraction by Sedum alfredii is affected by continual clipping and phosphorus fertilization amendment

Improving the efficacy of phytoextraction is critical for its successful application in metal contaminated soils. Mineral nutrition affects plant growth and metal absorption and subsequently the accumulation of heavy metal through hyper-accumulator plants. This study assessed the effects of di-hydrogen phosphates (KH₂PO₄, Ca(H₂PO₄)₂, NaH₂PO₄ and NH₄H₂PO₄) application at three levels (22, 88 and 352 mg P/kg soil) on Sedum alfredii growth and metal uptake by three consecutive harvests on aged and Zn/Cd combined contaminated paddy soil. The addition of phosphates (P) significantly increased the amount of Zn taken up by S. alfredii due to increased shoot Zn concentration and dry matter yield (DMY) (P<0.05). The highest phytoextraction of Zn and Cd was observed in KH₂PO₄ and NH₄H₂PO₄ treatment at 352 mg P/kg soil. The amount of Zn removed by phytoextraction increased in the order of 1st clipping<2nd clipping<3rd clipping, and for Cd extraction the order was 2nd clipping<1st clipping<3rd clipping. These results indicate that the application of P fertilizers coupled with multiple cuttings can enhance the removal of Zn and Cd from contaminated soils by S. alfredii, thus shortening the time needed for accomplishing remediation goals.     

Biological sulfate removal from acrylic fiber manufacturing wastewater using a two-stage UASB reactor

A two-stage UASB reactor was employed to remove sulfate from acrylic fiber manufacturing wastewater. Mesophilic operation (35±0.5℃) was performed with hydraulic retention time (HRT) varied between 28 and 40 hr. Mixed liquor suspended solids (MLSS) in the reactor was maintained about 8000 mg/L. The results indicated that sulfate removal was enhanced with increasing the ratio of COD/SO₄^2-. At low COD/SO₄^2-, the growth of the sulfate-reducing bacteria (SRB) was carbon-limited. The optimal sulfate removal efficiencies were 75% when the HRT was no less than 38 hr. Sulfidogenesis mainly happened in the sulfate-reducing stage, while methanogenesis in the methane-producing stage. Microbes in sulfate-reducing stage performed granulation better than that in methane-producing stage. Higher extracellular polymeric substances (EPS) content in sulfate-reducing stage helped to adhere and connect the flocculent sludge particles together. SRB accounted for about 31% both in sulfate-reducing stage and methane-producing stage at COD/SO₄^2- ratio of 0.5, while it dropped dramatically from 34% in sulfate-reducing stage to 10% in methane-producing stage corresponding to the COD/SO₄^2- ratio of 4.7. SRB and MPA were predominant in sulfate-reducing stage and methane-producing stage respectively.     

温州市售贝类中重金属含量的分析与评价

调查了温州市售贝类中重金属(Cu、Pb、Cd、Cr、As、Hg)的含量,并采用《农产品安全质量无公害水产品安全要求》(GB 18406.4-2001)对检测结果进行评价。检测结果显示:温州市售贝类中Cu:1.23~10.67 mg/kg,Pb:ND~0.47 mg/kg,Cd:0.055~0.579 mg/kg,Cr:0.24~4.12mg/kg,As:0.39~2.95 mg/kg,Hg:0.014~0.036 mg/kg。市售贝类中Cu、Pb、Hg含量低于限量标准,但Cd、As、Cr有超标。说明温州市售贝类存在食用风险,应引起足够的重视。