Removal and transformation of organic matters in domestic wastewater during lab-scale chemically enhanced primary treatment and a trickling filter treatment

To find a simple and economical way for treating the domestic wastewater in small counties and towns, a process combining chemically enhanced primary treatment and a trickling filter (CEPT-TF, representing the physical and biological effects) was constructed and operated in laboratory conditions. The characteristic behaviors of dissolved organic matter in raw wastewater and effluents were examined during steady-state operation. Experimental results showed that the process of CEPT and TF in series was beneficial for the removal of hydrophobic and hydrophilic organics. Specially, the hydrophobic and aromatic materials could be preferentially removed in the CEPT unit, and the hydrophilic fraction in the TF. Structural changes of the organic fractions during the operation of the different units were also characterized via spectrum analysis.     

中国三个不同富营养化湖泊沉积物中Cu、Zn赋存特征及其与营养盐的相关性分析

对太湖、南四湖、白洋淀三个不同富营养化湖泊沉积物进行采样,采用Tessier连续提取法,测定了3个湖泊表层沉积物中Cu、Zn两种重金属的赋存形态,并初步探讨了重金属各形态与沉积物及上覆水中营养盐的相关关系。结果表明,沉积物中重金属总量以白洋淀最高,太湖最低,但重金属污染程度为太湖＆gt;南四湖＆gt;白洋淀,太湖Cu污染指数为1.34~1.6,白洋淀Cu污染指数仅为0.79~1.17。沉积物中重金属赋存形态Cu主要以残渣态和有机质结合态为主（二者之和占73%以上）, Zn则以残渣态和Fe-Mn氧化态占优（二者之和比例达83%以上）,含量最少的均为可交换态。不同湖泊沉积物重金属赋存形态差异较大,太湖残渣态重金属占总量的比例最小（Cu为43%~56%,Zn为49%~63%）,南四湖残渣态占的比例最大（Cu为59%~82%、Zn为64%~77%）;可交换态比重在太湖中最高（Cu占3.2%~5.6%,Zn为1.3%~1.5%）,在南四湖中最低（Cu为1.1%~2.9%,Zn未检出）。从“非稳定态”重金属（除残渣态外的四种形态之和）所占比例看,相较其它两个湖泊,太湖沉积物中重金属污染人为输入的活性态占较大比重,具有较高的二次释放风险。相关性分析得出,重金属Cu的可交换态与上覆水中总氮及总磷之间存在着极显著的正相关关系,碳酸盐结合态Cu与沉积物中营养盐呈现出显著的负相关性,说明水体的富营养化程度加剧可能会增强沉积物中Cu向水体释放的风险。     

共沸-分馏连续操作处理醇酮装置酸性废水

为了降低环己醇、环己酮生产装置产生的含甲酸废水的COD,使其达到排放标准,降低废水排放量,减少环境污染的目的,根据共沸-分馏间歇操作处理醇酮装置酸性废水研究获得的工艺参数,采用共沸-分馏连续操作处理该酸性废水,并从中回收甲酸。介绍了共沸-分馏连续操作处理醇酮装置酸性废水的工艺过程、操作方法,给出了共沸-分馏连续操作处理该废水并回收甲酸的实验数据,完成了间歇操作改连续操作过程的工艺研究,研究结论为进一步工业化生产装置设计奠定了基础。通过研究得出,采用共沸-分馏连续操作处理该酸性废水,废水的COD由1.6×105mg/L降至3.0×102mg/L以下,达此标准水为80%以上,废水的COD去除率达到99%以上,甲酸回收率80%,连续操作实验结果优于间歇操作。     

大气痕量挥发性有机物碳同位素分析研究进展

对于大气痕量挥发性有机物的研究,浓度测量方法在满足科学研究的要求方面尚有欠缺,相比之下,同位素测量方法具有测量精度高、对源解析准确和测量误差小的特点且发展迅速,该方法在大气痕量挥发性有机物的研究中所起到的作用日益显著;但由于同位素测量技术对大气样品质量的要求很高,故目前该方法在大气环境科学的研究领域中还不能普及,今后随...     

Distribution and Fractionation of Copper in Soils of Apple Orchards (5 pp)

Background Frequent application of Bordeaux mixture, which includes copper, as a fungicide in fruit and grape orchards may lead to copper accumulation in the soil, especially when orchard age and application times increase. The objectives of this study were: (i) to investigate the copper content and its spatial distribution in orchard soils; (ii) to identify the copper fractionation in soil and its relationship with plant uptake; (iii) to understand the characteristics of copper contamination in orchard soils. Materials and Methods Soil profile samples were taken in apple orchards with ages of 0, 5, 10, 20, 30 years and pot experiments were also carried out to study the effects of external copper input on copper fractionation. All soil samples were air-dried, ground and extracted with 0.43 mol L–1 HNO3 for the total absorbed copper. Fractionation determination was conducted following Tessier and Shuman sequential extraction methods, and copper was measured with AAS. Plant samples were first dry ashed, dissolved with 6 mol L–1 HCl and then copper and other elements were measured with ICP-MS.Results and Discussion Soil total Cu was higher in the apple orchards than that in non-orchard fields and was seen to have increased with orchard age. Soil Cu increased substantially with the average annual copper increase, ranging from 2.5 to 9 mg Cu kg–1. The distribution of copper in the soil profile was uneven, decreasing from surface to deeper layers, and the differences were significant, but the contents in every layer were also significantly correlated with those in the next layers. For all copper fractions, the organically bound, crystalline Mn oxide bound, and amorphous Fe bound fractions extracted with the Shuman method were much higher than the exchangeable and residual fractions. Using the Tessier method, organically bound, carbonate bound and Fe-Mn oxide bound fractions were much higher. With an increase in external copper input, the organically bound, crystalline Mn oxide bound and amorphous Fe bound fractions in the Shuman method and organically bound, carbonate bound and Fe-Mn oxide bound fractions in the Tessier method all increased significantly, while the changes in other fractions were not significant. Soil total copper and copper fractions were found to have good correlations with apple tree uptake. Copper in fruit flesh had significant correlations with soil total content in the 0–10 cm layer, all the copper fractions in the 0–5 cm layer, and some fractions in the deeper layers. Conclusion Copper content in orchard soils increased significantly with intensive application of Bordeaux mixtures and orchard age. Copper content decreased sharply from the topsoil to deeper soil layers. The copper contents in different layers also significantly correlated with those in the next layers. Dominant fractions of the copper in soil were mainly associated with organic matter, iron and manganese oxides and carbonates. A close relationship was found between the copper content in soils and in apple tree organs (which contained 8.9 to 66mg kg–1 Cu). Recommendation and Perspective Though most copper in the soil was specifically adsorbed or immobilized, and copper was mainly distributed in topsoil, which was essentially devoid of roots, the copper concentration of fruit still had significantly positive correlations with soil copper and most copper fractions. Therefore, measures must be taken to control copper accumulation in orchard soils and to make the apple fruit production sustainable.     

Assessing microbial degradation of o-xylene at field-scale from the reduction in mass flow rate combined with compound-specific isotope analyses

In recent years, natural attenuation (NA) has evolved into a possible remediation alternative, especially in the case of BTEX spills. In order to be approved by the regulators, biodegradation needs to be demonstrated which requires efficient site investigation and monitoring tools. Three methods--the Integral Groundwater Investigation method, the compound-specific isotope analysis (CSIA) and a newly developed combination of both--were used in this work to quantify at field scale the biodegradation of o-xylene at a former gasworks site which is heavily contaminated with BTEX and PAHs. First, the Integral Groundwater Investigation method [Schwarz, R., Ptak, T., Holder, T., Teutsch, G., 1998. Groundwater risk assessment at contaminated sites: a new investigation approach. In: Herbert, M. and Kovar, K. (Editors), GQ'98 Groundwater Quality: Remediation and Protection. IAHS Publication 250, pp. 68-71; COH 4 (2000) 170] was applied, which allows the determination of mass flow rates of o-xylene by integral pumping tests. Concentration time series obtained during pumping at two wells were used to calculate inversely contaminant mass flow rates at the two control planes that are defined by the diameter of the maximum isochrone. A reactive transport model was used within a Monte Carlo approach to identify biodegradation as the dominant process for reduction in the contaminant mass flow rate between the two consecutive control planes. Secondly, compound-specific carbon isotope analyses of o-xylene were performed on the basis of point-scale samples from the same two wells. The Rayleigh equation was used to quantify the degree of biodegradation that occurred between the wells. Thirdly, a combination of the Integral Groundwater Investigation method and the compound-specific isotope analysis was developed and applied. It comprises isotope measurements during the integral pumping tests and the evaluation of delta13C time series by an inversion algorithm to obtain spatially integrated mean isotope values at the control planes. It was shown that the Rayleigh equation is applicable to spatially integrated mean isotope values in order to obtain the mean biodegradation between the consecutive control planes. All three approaches yielded consistently a 98-99% degradation of o-xylene.     

黑柱石和水之间氢同位素平衡分馏的实验研究

在750-250℃温度范围内,对黑柱石-水之间的氢同位素平衡分馏进行了实验研究。研究中改进了氢同位素交换实验方法,从而保证了精度。研究结果表明,750-550℃温度范围内,黑柱石一水的分馏系数10~3lnα°_(黑柱石-水)=-30.51 10~6/T~2-59.86,550-350℃温度范围内,10~3lnα°_(黑柱石-水)与温度1/T~2间无依赖关系,其值为-105.0±0.7,.250℃时,交换率太低。文中讨论了黑柱石-水之间氢同位素分馏系数与温度、矿物晶体结构、矿物化学组成的关系及其地质意义。     

盐城凹陷凝析油地球化学特征

运用碳同位素、气相色谱、色谱 质谱、流体包裹体技术 ,研究了盐城凹陷凝析油地球化学特征 ,并与永安凹陷永 7井凝析油、下扬子海相原油进行了对比。该凝析油碳同位素为 -2 8 8‰～ 3 0 5‰ ,全油色谱中含有一定的长链正构烷烃 ,Pr/Ph为 1 5 6,三环萜烷含量高 ,伽玛蜡烷含量低 ,重排甾烷含量高 ,C2 9甾烷 >>C2 7甾烷 >C2 8甾烷。石蜡指数、庚烷值表明原油为高成熟凝析油 ,甲基菲指数MPI表明原油为未熟—低熟原油 ,C2 9甾烷 2 0S/ (2 0S+2 0R)值表明原油为成熟原油。这种成熟度的差异可能与不同成熟度原油的混合作用有关。油气主要充注时间为 6～ 1 5Ma。凝析油的主体可能源于泰州组烃源岩 ,凝析油的形成与蒸发分馏作用密不可分     

南方天然水体DOM的化学分级、变化特征及三卤甲烷生成势(THMFP)特性研究

采用XAD树脂吸附法,在春季内(3～5月)连续对南方深圳水库中的水体溶解性有机物(DOM)进行化学分级表征.结果表明,天然水体DOM的总量和单个化学分级组分含量在一个季节会发生一定的波动,但总的分布特征在季节内未发生根本变化,即憎水酸(HoA)和亲水部分(HiM)浓度始终较高,而憎水碱(HoB)、憎水中性物(HoN)、弱憎水酸(WHoA)浓度则相对较低.同时,选取代表性时间点对DOM各化学分级组分进行了消毒副产物三卤甲烷生成势(THMFP)的研究,发现三卤甲烷(THMs)的主要前驱物为憎水和弱憎水有机部分,对THMFP的贡献共占约80%.进一步研究发现,憎水中性物、憎水酸、弱憎水酸的THMs生成能力较强,总体上与紫外吸收能力基本一致;但弱憎水酸表现略有不同,其SUVA(100×UV254/DOC)值并不十分突出,但三卤甲烷生成能力却明显较高,说明DOM的紫外吸收特性不能完全作为THMFP特性的替代指标.亲水物质(HiM)的SUVA值也不高,但其THMs生成能力接近憎水酸部分,值得水处理工艺研究重点关注.     

Pb和Cd赋存形态与土壤理化性质相关性研究

选择我国14种具有代表性的重金属污染土壤,测定其主要理化性质（pH、阳离子交换量、有机质、粉粒和黏粒）,采用改进的BCR顺序提取法对其中的Pb和Cd进行形态分析,运用SPSS 20.0软件进行Pearson相关性分析,建立逐步回归模型,研究重金属赋存形态与理化性质的相关性。结果表明,Pb和Cd的酸可溶态与pH值呈极显著负相关,相关性系数r分别为-0.80和-0.78,与阳离子交换量呈显著正相关,r分别为0.54和0.61,与有机质、粉粒和黏粒无相关性;Cd的可还原态与有机质呈显著正相关,r=0.56,与其它理化性质无相关性;可氧化态与有机质和黏粒呈显著正相关,与其它理化性质无相关性;残渣态与主要理化性质均无显著相关性。由逐步回归模型发现,酸可溶态、可还原态、可氧化态与理化性质回归效果均较好。