采用强酸型阳离子交换树脂分离铝离子和磷酸盐

三氯硫磷作为重要的农药中间体,在生产过程中可能产生高浓度Al~(3+)与磷酸盐共存的强酸性废水,有效分离Al~(3+)与磷酸盐并进一步分别对其回收利用具有重要意义。围绕上述问题,选择001×7强酸型苯乙烯系阳离子交换树脂,研究了Al~(3+)与磷酸盐在单一和共存体系下的动态吸附交换行为。研究发现,该树脂对Al~(3+)有良好的吸附性能,Al~(3+)穿透曲线表现为典型的"S"型,采用Thomas模型可以很好地模拟Al~(3+)吸附过程。当初始Al~(3+)浓度([Al~(3+)]0)为1 000 mg·L~(-1)且流速为4、6和10 BV·h~(-1)时,穿透交换容量(Al~(3+)平衡浓度为10 mg·L~(-1))分别为14.08、12.16和11.09 mg·g~(-1);磷酸盐的存在促进了Al~(3+)的交换,当体系存在4 300 mg·L~(-1)磷酸盐时,穿透交换容量分别提高了16.50%、9.61%和6.37%。对于吸附饱和的树脂,采用4%HCl溶液可达到98.3%再生率。采用阳离子交换树脂分离Al~(3+)与磷酸盐共存废水,这可能是实现二者分离与后续回收的有效手段之一。     

破络-Fenton法处理化学镀镍废水并回收水中的磷酸盐

以电镀厂化学镀镍的混合清洗水为处理对象,采用CaO破络吸附联合Fenton氧化的多级物化技术去除废液中的镍离子和磷酸盐,研究CaO投加量和反应时间对镍离子去除效率的影响以及Fenton试剂投加量、反应初始pH对废液中磷处理效果的影响。结果表明,通过两段式反应,当CaO投加量为2 g·L~(-1)、反应时间1 h;反应初始pH为4、H_2O_2投加量9.18 mg·L~(-1)、m(H_2O_2)/m(Fe~(2+))为5∶1、反应时间180 min时,镍离子和总磷(TP)含量由原来的64.6和90.2 mg·L~(-1)分别降低至0.43和0.46 mgl·L~(-1),均达到国家《污水综合排放标准》(GB 8978-1996)。处理后沉淀物经测试符合Fe_2(PO_4)_3晶体及其形貌特征,达到了资源回收的目的。     

CPB改性沸石对磷酸盐的吸附-解吸性能研究

采用溴化十六烷基吡啶(CPB)对天然沸石进行改性,并考察了CPB改性沸石对磷酸盐的吸附-解吸性能。结果表明,CPB改性沸石对磷酸盐具备一定的吸附能力,且吸附行为满足Langmuir等温吸附模型;粒径、改性剂投加量、反应温度、pH值及共存阴离子等因素均会影响CPB改性沸石对磷酸盐的吸附能力;减小粒径和降低反应温度均有利于CPB改性沸石对磷酸盐的吸附去除;粒径≤0.18 mm CPB改性沸石吸附磷酸盐较优的改性剂投加量为250 mmol/kg;当溶液的初始pH值位于4~10之间时CPB改性沸石对磷酸盐的吸附能力随pH值的增加而增强;SO42-的存在会明显降低CPB改性沸石对磷酸盐的吸附效率,而提高溶液的pH值有助于消除SO42-存在对CPB改性沸石吸附磷酸盐的负面影响;HCO3-的存在会一定程度上抑制CPB改性沸石对磷酸盐的吸附去除,而提高溶液的pH值无法消除HCO3-存在对CPB改性沸石吸附磷酸盐的负面影响;CPB改性沸石吸附磷酸盐后一定条件下可以重新解吸出来,且随着解吸液SO42-浓度的增加解吸率明显增大。     

2种磷酸盐生长环境对同步去除与富集磷酸盐工艺的影响

针对同步去除与富集磷酸盐溶液的问题,研究了在低磷环境和低磷高磷交替环境下悬浮填料生物膜反应器的除磷能力和释磷能力,采用扫描电子显微镜(SEM)和高通量测序对第0、45和95天的污泥进行了表征。结果表明:低磷环境下好氧出水磷酸盐浓度稳定在0.5 mg·L~(-1)以下,厌氧阶段的最大释磷量为6.05 mg·L~(-1);在低磷高磷交替环境中,好氧出水磷酸盐浓度基本在0.5 mg·L~(-1)以下,富磷溶液浓度最高可达63 mg·L~(-1)。SEM结果表明,同步去除与富集磷酸盐的悬浮填料生物膜反应器中的主要微生物是杆状菌。高通量测序结果表明:第0、45和95天的变形菌门(Proteobacteria)的相对丰度分别为48.3%、57.1%和89.1%,占主导地位;而红环菌科(Rhodocyclaceae)的相对丰度分别为18.1%、19.0%和30.8%,是反应器中的优势菌科;动胶菌属(Zoogloea)是同步去除与富集磷酸盐的悬浮填料生物膜工艺中的主要功能菌。在悬浮填料生物膜工艺中,低磷高磷交替的生长环境下培养的聚磷生物膜能够使好氧出水的磷酸盐浓度达到国家排放标准,并在厌氧阶段得到高浓度的磷酸盐富集溶液,且这种生长环境更适合聚磷微生物的生长。     

FeCl_3改性柚子皮吸附去除水中的砷

以生物质废弃物柚子皮为主要原料,通过在柚子皮粉中加入FeCl_3进行改性,将该改性产物用于吸附去除水中的砷。该改性柚子皮的制备条件为柚子皮粉:FeCl_3质量比为50∶1,常温下加水混合均匀,在(85±2)℃条件下烘24 h后粉碎。当水中砷离子浓度为1.5~30 mg·L~(-1),pH值为2~9,吸附剂投加量为10 g·L~(-1),吸附反应温度为20℃的条件下,吸附反应30 min后达到平衡,去除率最高达到96.19%,单位吸附量q最大值为1.86 mg·g~(-1)。该吸附反应符合Freundlich等温方程,该去除机制可能以金属沉淀、静电吸附、絮凝作用和共沉淀作用为主。研究表明该改性吸附材料可自动调节废水pH值,操作简单,无二次污染,考虑用作中等浓度含砷废水的预处理,有利于生物质废弃物的资源化利用。     

改性高炉渣对甲基橙的吸附

以盐酸和十六烷基三甲基溴化铵对包钢高炉渣进行表面改性,通过XRD、SEM和N_2吸附-脱附测试研究其微观结构和孔径分布,并以阴离子型染料甲基橙溶液为模拟染料废水研究其吸附性能,进而探索最佳改性制备条件。研究结果表明:有机改性高炉渣主要化学成分为SiO_2,表面有明显的孔道结构,比表面积高达394.5 m~2·g~(-1),平均孔径为12.4 nm;有机改性高炉渣对甲基橙溶液均具有较强的吸附性能,最佳改性条件为加入改性剂盐酸浓度为3 mol·L~(-1)、十六烷基三甲基溴化铵的最终投加浓度为8 g·L~(-1)、水热温度160℃和16 h,此时所制备的有机改性高炉渣吸附性能最强,吸附率为98.06%,最大吸附量达357.14 mg·g~(-1)。等温吸附实验表明,有机改性高炉渣对甲基橙溶液的吸附属于多分子层吸附。     

改性沸石对水中微量汞的吸附性能

为了更好的去除水体中微量汞,研究了采用二氧化锰和壳聚糖对天然斜发沸石进行改性,着重考察了pH、温度、离子强度、Hg~(2+)初始浓度和时间对改性前后沸石吸附Hg~(2+)的影响,并研究了其吸附机理。结果表明,改性沸石受pH、温度和离子强度影响较小,在pH、温度、离子强度和初始浓度为6、25℃、0.05 mol·L~(-1)和50μg·L~(-1)时,二氧化锰+壳聚糖改性沸石(ZCM)对Hg~(2+)的去除率高达99%,符合国家饮用水标准,并且二氧化锰+壳聚糖改性沸石(ZCM)具有更好的解吸再生性。3种沸石均较好的符合Langmuir等温吸附模型和假二级动力学模型,其中改性沸石对汞的吸附主要为离子交换和表面官能团的络合作用,二氧化锰+壳聚糖改性沸石(ZCM)和壳聚糖改性沸石(ZC)饱和吸附量由1.43 mg·g~(-1)提高到5和3.3 mg·g~(-1),吸附平衡时间由10 h减少至1和4 h,为治理汞微污染地表水提供一定的理论支持。     

酒糟生物炭负载铝对饮用水中氟的去除

以酒糟生物碳为原料,采用负载Al(OH)_3改性制得生物吸附剂(CDGB)。通过静态吸附实验研究吸附剂用量、初始浓度、吸附时间、pH值和共存离子对CDGB吸附氟能力的影响。结果表明:CDGB具有非常宽的最适pH值范围,在pH值为5.0~9.0范围内CDGB均能有效地去除饮用水中的氟离子;并且在氟初始浓度为10 mg·L~(-1),吸附时间40 min,CDGB的添加量为2 g·L~(-1)时氟的去除率可达90%以上,且吸附后水中氟离子含量低于1 mg·L~(-1),符合国家饮用水标准;溶液中常见的共存离子(硝酸根、氯离子和硫酸根)对吸附剂吸附没有显著影响;CDGB对氟离子吸附过程符合Langmuir吸附等温线模型和伪二级吸附动力学模型,理论饱和吸附容量为18.05 mg·g~(-1)。     

有机改性蒙脱石负载巯基修复汞污染土壤

以蒙脱石作为原始材料,对其进行有机改性,将巯基基团负载在有机改性的蒙脱石上制备出重金属汞的稳定剂以稳定化修复汞污染土壤。考察稳定化时间、稳定剂添加量、浸出液pH及有机质含量对稳定化效果的影响,探究稳定化前后土壤汞形态变化。通过XRD、FTIR和SEM分析了蒙脱石、有机改性蒙脱石(Mont-OR)和负载巯基有机改性蒙脱石(Mont-OR-SH)的物理化学特征,通过原子吸收法测定汞浓度。稳定化修复结果表明,稳定化时间为30 d,稳定剂添加量为9%时,汞浸出浓度为0.066 mg·L~(-1),稳定率为98.3%,达到GB 5085.3-2007规定的汞限值0.10 mg·L~(-1)。添加不同质量的小麦秸秆作为有机质的来源,均对整个稳定化有促进作用,其中添加量为6%时,促进作用最明显,改变浸出液pH,在强酸性和强碱性条件下,利用此稳定剂对汞的稳定作用降低。TESSIER五步提取法结果表明,负载巯基的有机改性蒙脱石的添加导致可交换态汞、碳酸盐结合态汞、铁锰氧化物结合态汞含量下降,而有机结合态汞、残渣态汞含量增加。实验结果证明有机改性蒙脱石负载巯基能够有效地应用于汞污染土壤修复。     

改性谷壳生物炭负载磁性Fe去除废水中Pb~(2+)的效果及机制

将谷売生物炭用酸改性后负载磁性Fe_3O_4,得到一种新的吸附材料(BC~Fe)。通过单因素吸附实验,研究了时间、pH、添加量、浓度以及温度等参数对BCTe吸附废水中Pb~(2+)的影响,并对其进行比表面积及傅里叶红外光谱分析,探讨该磁性生物炭对Pb~(2+)的吸附机理。结果表明对Pb~(2+)的吸附能在2 h内基本达到平衡。在Pb~(2+)溶液初始浓度为100mg·L~(-1),pH=5.0温度为25℃,分別添加0.1g和0.15 g的BC-Fe于50 mL Pb~(2+)溶液中,单位质量的BC-Fe对溶液中Pb~(2+)的吸附量分别为40.6 mg·g~(-1)和33.2 mg·g~(-1)去除率分别为81.3%和99.9%。该吸附过程符合拟二级动力学模型,理论平衡吸附量为43.9 mg·g~(-1)。用Langmuir等温吸附方程能够很好地描述其吸附行为;热力学研究表明对Pb~(2+)的吸附过程是自发的吸热过程。     

Optimization of Height of Release of Air Pollutants

A number of key projects in the Environmental Protection Agency (EPA) particulate R&;D program having applicability to industry are presented. For electrostatic precipitators (ESP) there is presented the result of work on large diameter discharge electrodes which provide a decrease in penetration of up to a factor of 4 when compared to conventional small diameter electrodes. Also discussed is the multistage ESP which provides a collection efficiency that would require a collecting plate area 4 or 5 times larger with conventional ESP technology. The E-SOX technology makes use of the multistage concept to free up space in the ESP for SO₂ removals of up to 90%. Electrostatically augmented fabric filtration provides a reduction in pressure drop of about 5 0% as compared to conventional fabric filtration. Wind tunnel modeling of windbreaks for material storage piles indicates a potential for providing engineering design data that would allow significant emission reduction caused by wind erosion     

Investigation of the characteristics of the reflectivity of clouds

This paper investigates some of the reflectivity characteristics that clouds (when modelled as solid bodies) must exhibit to be compatible with observations that the reflecting surface of a cloud (i) appears almost equally bright across its face, (ii) is brightest when the cloud is opposite to the Sun but decreases in brightness as the cloud moves to other positions and (iii) increases in brightness with increasing optical thickness of the cloud in the observer's line of sight. These observations, respectively, are shown to imply that the peak value of the bidirectional total reflectivity from a cloud surface (i) increases in inverse proportion to the cosine of the angle between the Sun and the normal to the cloud surface, as the incident angle increases, (ii) appears to be directed back in the direction of the incident radiation, and (iii) increases as optical thickness of the cloud in the observer's line of sight increases. The results could have application in many fields (e.g. modelling diffuse radiance distributions for cloudy skies).     

次氯酸钠发生器的研制

介绍了电解法生产次氯酸钠的原理 ,并在原有生产工艺的基础上进行了重新设计和对设备的重新选择、改造 ,得出了各个工艺参数的最佳值 ,生产出高品质的次氯酸钠     

Estimation of uncertainty of sampling for analysis of pesticide residues

Abstract

A computer model was used to take random samples from primary sample populations obtained from field trials to simulate the uncertainty of sampling for residue analysis of plant commodities and soil. The results indicate about 40%, 30% and 20% relative uncertainty when random samples of size 5, 10 and 25 are taken respectively, from a single lot. Therefore the sample size should be the same for establishing and enforcing legal limits.     

扬中生态环境建设的思考与实践

结合扬中生态环境的基本情况和存在的不足，进行了具体分析，对扬中未来生态建设的发展方向提出了建议及实施措施。     

实验室质量管理体系内部审核的策划

在实施ISO／IEC 17025：1999标准《检测和校准实验室能力的通用要求》过程中，通过实验室质量管理体系内部审核的实践与系统分析，识别出内部审核策划阶段的关键环节，提出审核范围确定、审核计划和抽样方案制订的质量控制要求，为有序高效地实施内部审核提供了技术方法。     

实验室质量管理体系内部审核的实施

在实施ISO／IEC17025：1999标准《检测和校准实验室能力的通用要求》过程中，通过实验室质量管理体系内部审核的实践与系统分析，识别出内部审核实施阶段的关键环节，提出召开首次会议、收集审核证据、确定审核发现和召开末次会议的技术方法，对提高内部审核的质量和有效性、获得可靠的审核结论具有重要意义。     

Comparison of methods for evaluation of activity of photocatalytic films

Objective

This work aims to investigate the correlation between the photocatalytic activity determined by methylene blue bleaching (DIN 52980), stearic acid degradation, and degradation of acetone in gas phase.

Method

The photocatalytic TiO₂ coatings included in this investigation ranged from thin commercially available coatings (Activ^TM and BioClean^TM) and ready to use suspensions (Nano-X PK1245) to lab-produced PVD and sol?Cgel coatings. XRD analysis of the photocatalytic coatings showed that all the coatings consisted of nanocrystalline anatase, although the thickness and porosity varied considerably.

Results

The study showed that the reproducibility of the activity measurements was good. However, more importantly, the investigation showed that there is a good correlation between the activities determined by the different methods even though the characteristics of the photocatalytic coatings and the organic probe molecules varied considerably.

Conclusion

The overall findings of this work suggest that there is a good correlation between the investigated methods. These results are promising for the future work concerning standardization of methods for determination of the activity of photocatalytic films.     

Impact of overexploitation of shellfish: northeastern coast of India

India has a very extensive coastline of about 7515 km, rich in diverse living resources. These resources continue to deteriorate with rampant harvesting or are altered for other uses such as aquaculture and fisheries. The present paper deals with degrading coastal habitats in northeastern India, and projects the intensity of the stress arising from the collection of tiger prawn seeds (Penaeus monodon) for aquacultural farms and molluskan shells for poultry feed and edible lime. Indiscriminate exploitation of these resources leads to a heavy reduction of the species concerned and other associated marine communities. The magnitude of such destruction has been quantified. The impacts of biodiversity loss and their after-effects on the ecobalance of this coastal system have become a matter of great concern to ecologists to maintain security and sustainability. The authors propose a public awareness program on themes relating to the importance of biodiversity for human livelihoods.