分类前后苏州市生活垃圾管理的环境效益比较

为系统认识生活垃圾分类对城市环境效益的提升,基于2017~2021年苏州市推行分类前后生活垃圾的处置数据,核算整个收运-处置过程的环境影响潜值,预测苏州市到2035年生活垃圾全过程管理的环境效益. 苏州市自2019年底全面实施生活垃圾分类后,单位质量生活垃圾的环境影响潜值（以PET₂₀₀₀计,下同）由2017年的2.34×10^-13 t^-1降至2021年的1.91×10^-13 t^-1,降幅18.38%,分类可改善生活垃圾全过程管理的环境效益. 以苏州市2021年生活垃圾清运情况为基准,设定不同前端分类效果-后端分质处置规模情景测算,发现生活垃圾前端分类效果梯度提升且末端分质处置能力相应配套后环境效益进一步提升,厨余垃圾分出率和纯度分别提高至40%和95%且实现“垃圾零填埋”的规划处置能力情景下,单位质量垃圾环境影响潜值和碳排放总量较2021年实际情况分别减少23.96%和30.73%. 建立基于苏州市人口规模及经济发展水平的线性模型,预计到2035年苏州市的生活垃圾清运量达696.50万t. 在苏州市生活垃圾前端分类不断改善及环境卫生持续优化的背景下,基于苏州市末端处置能力现状,至2035年分类效果提高后单位质量生活垃圾环境影响潜值为1.54×10^-13 t^-1,总环境影响潜值1.05×10^-6,碳排放总量达到380.17万t;在垃圾末端分质处置规模扩大、原生生活垃圾“零填埋”、厨余垃圾充分资源化的理想情景下,2035年单位质量生活垃圾环境影响潜值为1.28×10^-13t^-1,总环境影响潜值和碳排放总量分别为8.69×10^-7和322.57万t,分别较2021年实际情况减少约5.65%和1.23%. 统筹推进分类收运和分质处置的协同,能更好地控制生活垃圾管理过程的潜在环境影响和碳排放.     

大气颗粒物酸缓冲能力来源解析技术与应用

建立了大气颗粒物酸缓冲能力的表征方法,测定了天津市区不同源类的酸缓冲能力;建立了基于二重源解析技术(NCMB)的TSP酸缓冲能力来源识别技术,阐述了其技术原理,并在天津城区加以应用.结果表明,大气中颗粒物浓度和降雨量是影响天津城区降雨pH值的关键因素;颗粒物的酸缓冲能力主要来源于城市扬尘、建筑水泥尘和土壤风沙尘等开放源.开放源污染是现阶段决定天津城区酸雨发展的关键因素之一.     

动力波洗涤器脱硫试验研究

采用动力波洗涤器冷模试验装置,在不加脱硫剂的情况下,考察各操作参数(液气比、pH值)及液柱喷射方式(逆喷、顺喷)对脱硫效率的影响,并对不同水质的清水(自来水、去离子水)的脱硫效率进行对比分析。结果表明:自来水的脱硫效率随液气比的增加而增大;逆喷时的脱硫效率明显高于顺喷;液气比>7时,逆喷的脱硫效率在75%以上;自来水的脱硫效率较去离子水要高;撞击流有强化吸收的特性。     

ARTIFICIAL NEURAL NETWORKS FOR SUBSURFACE DRAINAGE AND SUBIRRIGATION SYSTEMS IN ONTARIO,CANADA1

ABSTRACT: Artificial neural network (ANN) models were developed to simulate fluctuations in midspan water table depths (WTD) given rainfall, potential evapotranspiration, and irrigation inputs on a Brookston clay loam in Woodslee, Ontario, having a dual‐purpose subsurface drainage/subirrigation setup. Water table depths and meteorologic data collected at this site from 1992 to 1994 and from 1996 to 1997 were used to train the ANNs. The ANNs were then used for real‐time control and time series simulations. The lowest root mean squared errors (RMSE) for the various ANNs were 60.6 mm for real‐time control simulation, and 88.4 mm for time‐series simulation of water table depths. It was possible to simulate WTD for the different modes of water table management in one network by incorporating an indicator for switching from one to the other. The ANN simulations were quite good even though the training data sets had irregular measurement intervals. With fewer input parameters and small network structures, ANNs still provided accurate results and required little time for training and execution. ANNs are therefore easier and faster to develop and run than conventional models and can contribute to the proper management of subsurface drainage and subirrigation systems.     

天津局部大气颗粒物上多环芳烃分布状态

通过对天津市内的几个典型地区大气颗粒物进行测定,检测出58种多环芳烃,并对11种多环芳烃进行定量测定。其结果表明,所涉及 的区域在采暖期内大多数点位的苯并(a)芘超标,超标倍数在1.1～4.6之间;交通繁忙地区的多环芳烃的污染程度高于其他地区;笔者还对多 环芳烃在不同粒径颗粒物上的分布特征、苯并(a)芘与大气颗粒物进行相关性分析和评价。      

Distribution of aromatic amines,phenols, chlorobenzenes,and naphthalenes in the surface sediment of the Dianchi Lake,China

• The total organic pollutant concentrations in sediment were 27.4-1620 ng/g. • The phenol concentrations were relatively high in the sediment of the Dianchi Lake. • Average total concentrations decreased as follows: Caohai>Waihai>Haigeng Dam. • 1,4-dichlorobenzene, 3- or 4-methylphenol, 1,2,4-trichlorobenzene might be risks. Organic pollutants are widespread environmental pollutants with high toxicity, persistence, and bioaccumulation. Our aim was to investigate the distribution of aromatic amines, phenols, chlorobenzenes, and naphthalenes in the surface sediment of the Dianchi Lake, China. Nineteen surface sediment samples were collected from the Dianchi Lake, and 40 types of organic pollutants were analyzed via gas chromatography–mass spectrometry. The total organic pollutant concentrations in the surface sediment of the Dianchi Lake varied from 27.4 to 1.62 × 10³ ng/g. The concentrations of phenols were much higher than those in other water bodies but still within a controllable range, whereas the concentrations of the other organic pollutant classes were similar or even lower. The detection ratio of 3- or 4-methylphenol was the highest (100.00%) among the pollutants. The average total organic pollutant concentrations decreased in the following order: Caohai (540 ng/g)>the middle of Waihai (488 ng/g)>the edge of Waihai (351 ng/g)>Haigeng Dam (90.4 ng/g). Pearson analysis showed a strong correlation among 1-methylnaphthalene, 2-methylnaphthalene, 1,3-dinitronaphthalene, and 1,4-dinitronaphthalene (p<0.01). Caohai, the north lakeshore of Waihai and the south of Waihai showed higher risk because of high concentration; meanwhile, 1,4-dichlorobenzene, 3- or 4-methylphenol and 1,2,4-trichlorobenzene were more likely to cause risks.     

响应面法优化袋式除尘器脉冲清灰性能

基于计算流体动力学的方法采用三维、可压缩、非稳态流动数学模型对袋式除尘器脉冲清灰过程进行了数值模拟,得到了滤袋内外压差,并与文献实验值进行了比较,验证了仿真模型的可靠性。基于响应面法研究了喷吹压力、喷吹高度、滤袋直径和滤袋长度对脉冲清灰性能的影响,得到这4个影响因子的二次多项式预测模型,并进行优化。结果表明,喷吹压力为0.3 MPa,喷吹高度为0.2 m,滤袋直径为0.16 m,滤袋长度为6 m时,内外压差峰值最优,优化结果与仿真模拟结果相差小于3%。研究结果为袋式除尘器脉冲清灰系统的设计与优化提供了重要参考。     

Characterization of Cd-, Pb-, Zn-resistant endophytic Lasiodiplodia sp. MXSF31 from metal accumulating Portulaca oleracea and its potential in promoting the growth of rape in metal-contaminated soils

The aim of this study was to characterize the features of a Cd-, Pb-, and Zn-resistant endophytic fungus Lasiodiplodia sp. MXSF31 and to investigate the potential of MXSF31 to remove metals from contaminated water and soils. The endophytic fungus was isolated from the stem of Portulaca oleracea growing in metal-contaminated soils. The maximum biosorption capacities of MXSF31 were 3.0?×?10³, 1.1?×?10⁴, and 1.3?×?10⁴ mg kg^?1 for Cd, Pb, and Zn, respectively. The biosorption processes of Cd, Pb, and Zn by MXSF31 were well characterized with the pseudo-second-order kinetic model. The biosorption isotherm processes of Pb and Zn by the fungus were fitted better with the Langmuir model, while the biosorption processes of Cd was better fitted with the Freundlich model. The biosorption process of MXSF31 was attributed to the functional groups of hydroxyl, amino, carbonyl, and benzene ring on the cell wall. The active biomass of the strain removed more Cd, Pb, and Zn (4.6?×?10⁴, 5.6?×?10⁵, and 7.0?×?10⁴ mg kg^?1, respectively) than the dead biomass. The inoculation of MXSF31 increased the biomass of rape (Brassica napus L.), the translocation factor of Cd, and the extraction amount of Cd by rape in the Cd?+?Pb-contaminated soils. The results indicated that the endophytic fungus strain had the potential to remove heavy metals from water and soils contaminated by multiple heavy metals, and plants accumulating multiple metals might harbor diverse fungi suitable for bioremediation of contaminated media.     

巢湖入湖河流沉积物中有机磷的形态分级研究

为识别巢湖流域污染物的特征、来源及其沉积物有机磷各形态分布与富营养化的关系,测定了7条巢湖入湖河流沉积物中有机磷各形态的含量,分析不同污染类型人湖河流沉积物中有机磷各形态分布的差异及与其他因素间的相关性。研究发现,不同污染类型人湖河流沉积物中水土保持控制型河流沉积物中有机磷各组分的相对含量顺序为残渣态Po〉富里酸-Po〉HCl-Po〉胡敏酸-Po〉NaHCO3-Po,平均的相对比例为7．5：3．1：1．9：1．5：1．0,而城市污染控制型和面源污染控制型河流沉积物中有机磷各组分的相对含量顺序恰好相同,面源污染控制型河流沉积物Po各形态含量低于城市污染控制型和水土保持控制型河流。中活性P。和OM、TP、Pi、Po、TN、NaHCO3-Pi、NaOH—Pi呈正相关,非活性Po与Po、NaOH-Pi呈显著正相关关系,反映了中活性Po很容易转化为生物可利用磷和非活性Po,且非活性Po仍然具有潜在的生物活性。