分子筛催化剂生产废水的生物处理

采用氨化—硝化—反硝化三段联合生物工艺处理分子筛催化剂生产过程中产生的含有机胺废水。实验结果表明：在氨化过程中,当进水COD稳定为1 200~1 600 mg/L时,出水COD低于300 mg/L,COD去除率稳定在80%左右,当进水ρ（有机氮）为100~160 mg/L时,出水ρ（有机氮）均低于30 mg/L,有机氮去除率大于80%,在整个氨化过程中,出水ρ（氨氮）较进水ρ（氨氮）提高了35~200 mg/L;硝化过程中,当进水ρ（氨氮）小于等于300 mg/L时,出水ρ（氨氮）最终稳定在15 mg/L以内,氨氮去除率大于90%;在反硝化过程中,亚硝酸盐氮去除率基本稳定在98%以上,最终出水COD低于80 mg/L,出水ρ（总氮）低于25 mg/L。     

初级基质对降解菌Pseudomonas putida共代谢苯扎贝特的影响

通过对3,5-二硝基水杨酸(DNS)法测定还原糖含量各影响因素的筛选,优化确定了显色时间8 min,稳定时间10 min,最佳波长490 nm下进行吸光度测定的检测方法;分析分别以葡萄糖和麦芽糖作为外加碳源时,降解菌Pseudomonas putida B-31的生长情况和共代谢降解典型药物苯扎贝特(BZF)的过程。结果表明,降解菌只有在外加碳源的条件下才可正常生长,而且其在葡萄糖环境中生长得更好;拟合得到的葡萄糖、麦芽糖和BZF代谢动力学结果显示,葡萄糖对BZF去除的促进作用更为明显,同时从葡萄糖培养基中降解菌所提取的酶比活力要高于麦芽糖培养基,分析原因可能是葡萄糖所诱导的降解菌关键酶活力更强,而且还可能会产生不同的蛋白质点位。     

微波强化Fenton/活性炭工艺处理制药废水的影响因素

为了研究微波强化Fenton/活性炭工艺处理高浓度制药废水的影响因素,以阜新某集团公司生产制药原料排出的废水为研究对象,利用静态实验,采用混凝-微波强化Fenton/活性炭工艺对高浓度制药废水进行实验。实验用水为100 mL、COD为576~1 440 mg/L的制药废水,当活性炭投加量为2 g,H2O2投加量为3/4Qth,pH值为5,微波辐照功率和时间分别为500 W和7 min时,COD去除率可达到92.6%,出水COD在42.6~106.6 mg/L范围内。实验结果表明,活性炭的投加量、H2O2的投加量、pH值、微波辐照功率和辐照时间对微波强化Fenton/活性炭工艺的处理效果影响都较显著。     

应用自动识别和定量系统评价两种污水再生工艺对微量有机污染物的去除效果

采用气质联用分析,并结合自动识别与定量系统(AIQS-DB)考察2种再生水厂采用的深度处理工艺对微量有机污染物的去除效果。结果表明,以污水为原水的膜生物反应器(MBR)+臭氧氧化+生物活性炭滤池(BAC)工艺用于再生水生产,MBR工艺对有机污染物的去除起主要作用;城市污水厂二级出水为原水的混凝沉降+浸没式超滤(SMF)/连续微滤(CMF)+部分反渗透(RO)+臭氧氧化工艺用于再生水生产,其SMF和CMF工艺段的膜截留作用均可有效消减有机污染物含量,SMF的效果优于CMF;2种工艺中采用的臭氧技术都能进一步加强部分物质的去除效果。气质联用结合AIQS-DB可用于再生水中污染物的筛查和不同污水再生工艺对微污染物消减效果的评价。     

添加天然沸石和石灰对土壤镉形态转化的影响

采用土壤培养实验,研究镉污染土壤中添加沸石、石灰及两者配施对土壤pH值和土壤镉形态变化的影响。结果表明,土壤pH值随沸石用量的增加而增加,随培养时间呈现先增加后下降并逐渐趋于稳定的趋势,但均高于对照。高剂量石灰的处理对土壤pH的影响最大,与对照相比土壤pH提高了3.33个单位。在土壤5~50 d培养过程中,石灰处理的土壤交换态镉含量呈现先逐渐降低而后略有升高的趋势,其余处理均呈下降趋势。培养50 d后,高剂量的沸石、石灰及高剂量沸石与石灰配施处理的土壤交换态镉含量从5 d时的67.54、61.95和55.56 mg/kg降低至54.65、49.93和45.96mg/kg。相关分析表明,不同培养时期交换态镉含量与土壤pH值呈负相关关系。在10个处理中,L2Z3(石灰2 g/kg土和沸石60 g/kg土)组合处理效果最好,使土壤交换态镉含量下降了34.68%,碳酸盐结合态镉含量上升了4.30%,铁锰氧化结合态镉含量上升了16.97%,有机结合态镉含量上升了1.31%,残渣态镉含量上升了12.11%。     

Concentrations and distributions of 18 organochlorine pesticides listed in the Stockholm Convention in surface sediments from the Liaohe River basin,China

Organochlorine pesticides (OCPs) were analyzed in 26 surface sediment samples from the Liaohe River basin, and the distributions of and potential environmental risks posed by OCPs in the basin were evaluated. Eighteen OCPs listed in the Stockholm Convention were determined using isotope-dilution gas chromatography–high resolution mass spectrometry. This is the first study of hexachlorobenzene (HCB) in the Liaohe River basin sediments. The total OCP concentrations were 0.39–68.06 ng g^?1 dry weight. The total α-, β-, γ-, and δ-hexachlorocyclohexane (HCH), the total dichlorodiphenyltrichloroethane (DDT – p,p′-dichlorodiphenyldichloroethane (DDD), p,p′-dichlorodiphenyldichloroethylene (DDE), o,p^'-DDT, and p,p′-DDT), and the HCB concentrations in the sediment samples were 0.1–28.48 ng g^?1 (mean 4.01 ng g^?1), 0.08–6.52 ng g^?1 (mean 3.07 ng g^?1), and 0.18–24.8 ng g^?1 (mean 4.38 ng g^?1), respectively. The HCB concentrations were higher than the concentrations of the other OCPs, and the HCHs and HCB together were the dominant OCPs. β-HCH was the most abundant HCH isomer. The concentrations of DDTs and other OCPs were relatively low, and the (DDE+DDD)/DDT ratios (>0.5) and DDD/DDE ratios (<1) indicated that no recent DDT inputs had occurred in the Liaohe River system. The main sources of HCHs were probably the historical production and agricultural use of HCH in the study area. The DDT and HCH concentrations were generally below or similar to the concentrations that have been found in other parts of the world. An ecotoxicological evaluation indicated that HCHs in surface sediments pose slight risks to human and ecological health in the Liaohe River basin.     

The Wind-Frequency Allocation Method on Discharge Loading of Function Zones

Abstract

This paper introduces a new allocation method on discharge loading of each function zone in a total emission control region. The wind frequency, the position of each district, and the pollutant’s influence area were taken into account in this new method. The concept of “average downwind distance” was brought forward in this paper. The method here is more reasonable than the original method of area distribution, which was proposed by the “A-value” method in regulation of total emissions in China, by means of the simulation of annual average concentration in the total emission control region.     

Sources of Fine Particulate Species in Ambient Air over Lake Champlain Basin,VT

Abstract

This study is a part of an ongoing investigation of the types and locations of emission sources that contribute fine particulate air contaminants to Underhill, VT. The air quality monitoring data used for this study are from the Interagency Monitoring of Protected Visual Environments network for the period of 2001–2003 for the Underhill site. The main source-receptor modeling techniques used are the positive matrix factorization (PMF) and potential source contribution function (PSCF). This new study is intended as a comparison to a previous study of the 1988–1995 Underhill data that successfully revealed a total of 11 types of emission sources with significant contributions to this rural site. This new study has identified a total of nine sources: nitrate-rich secondary aerosol, wood smoke, East Coast oil combustion, automobile emission, metal working, soil/dust, sulfur-rich aerosol type I, sulfur-rich aerosol type II, and sea salt/road salt. Furthermore, the mass contributions from the PMF identified sources that correspond with sampling days with either good or poor visibility were analyzed to seek possible correlations. It has been shown that sulfur-rich aerosol type I, nitrate aerosol, and automobile emission are the most important contributors to visibility degradation. Soil/dust and sea salt/road salt also have an added effect.     

Winter Soil Respiration from Different Vegetation Patches in the Yellow River Delta, China

Vegetation type and density exhibited a considerable patchy distribution at very local scales in the Yellow River Delta, due to the spatial variation of soil salinity and water scarcity. We proposed that soil respiration is affected by the spatial variations in vegetation type and soil chemical properties and tested this hypothesis in three different vegetation patches (Phragmites australis, Suaeda heteroptera and bare soil) in winter (from November 2010 to April 2011). At diurnal scale, soil respiration all displayed single-peak curves and asymmetric patterns in the three vegetation patches; At seasonal scale, soil respiration all declined steadily until February, and then increased to a peak in next April. But, the magnitude of soil respiration showed significant differences among the three sites. Mean soil respiration rates in winter were 0.60, 0.45 and 0.17 μmol CO(2) m(-2) s(-1) for the Phragmites australis, Suaeda heteroptera and bare soil, respectively. The combined effect of soil temperature and soil moisture accounted for 58-68 % of the seasonal variation of winter soil respiration. The mean soil respiration revealed positive and linear correlations with total N, total N and SOC storages at 0-20 cm depth, and plant biomass among the three sites. We conclude that the patchy distribution of plant biomass and soil chemical properties (total C, total N and SOC) may affect decomposition rate of soil organic matter in winter, thereby leading to spatial variations in soil respiration.