大牛地气田污水预处理药剂加量研究

大牛地气田污水水质总体呈现高浊度、高矿化度、高腐蚀性、高含铁量及低pH值"四高一低"的特点。预处理阶段对后续处理过程起着重要的作用,试验确定了该阶段的加药量,提出了"一控二适量"的加药原则,选定JH-1、JH-2、JH-3的加量分别为300、50和2mg/L配合使用,使污水pH值控制在8.0～8.4之间,既节省了运行费用,又极大地缓解了处理过程中设备的结垢堵塞现象。     

生活垃圾焚烧飞灰水洗盐产生量预测及其对资源可持续利用的影响分析

针对水泥窑协同处置飞灰水洗预处理过程中水洗盐产生量不清,资源化利用潜力不明晰的问题,采用情景分析方法预测水洗盐产生量,评估其资源利用潜力。首先采用改进的灰色马尔科夫模型和产废系数法预测2021-2030年京津冀地区飞灰产生量;然后选择水泥窑协同处置比、厨余垃圾分拣率和塑料垃圾分拣率3个参数,利用组合情景预测协同处置和生活垃圾分类对水洗盐产生的影响。结果显示,到2030年,水洗盐产生量为9.2×10⁴~16.5×10⁴ t;在实现“十四五”时期飞灰资源化和生活垃圾分类发展要求的情景下,水洗盐产生量为12.7×10⁴ t,比低发展水平情景提高28.7%。提高垃圾分拣率,推进高效、低耗能分盐技术发展,可以降低水洗盐处理压力并提高氯化钾自给率,支持水洗盐资源可持续利用。     

污染区大气中多氯联苯的表征与分布研究初探

通过采集并分析污染区大气及大气颗粒物中PCBs的含量,揭示了污染区空气中PCBs的残留量,讨论了各样品中PCBs的组成及分布,气相样品中可检出的PCBs总浓度在19 1-641ng·m-3,颗粒物中可检出的PCBs同类物总浓度为0.191-0.373μg·g -1. 并对气相与颗粒物PCBs浓度的关系进行了初步探讨.对同类物分布的研究表明,无论气态还是大气颗粒物中低氯代的PCBs同类物都是其主要成份.     

Tank-dependence of the functionality and network differentiation of activated sludge community in a full-scale anaerobic/anoxic/aerobic municipal sewage treatment plant

● Environmental parameters affected functional bacteria and network associations. ● The structure and interactions of AS networks changed greatly within tanks. ● Anoxic co-occurrence network was more unstable and easily influenced. ● Composition of functional bacteria had a seasonal succession pattern. ● Tetrasphaera was the major PAO in spring and winter leading a better P removal. Understanding the structures and dynamics of bacterial communities in activated sludge (AS) in full-scale wastewater treatment plants (WWTPs) is of both engineering and ecological significance. Previous investigations have mainly focused on the AS communities of WWTP aeration tanks, and the differences and interactions between the communities in anaerobic and anoxic tanks of the AS system remain poorly understood. Here, we investigated the structures of bacterial communities and their inter-connections in three tanks (anaerobic, anoxic, and aerobic) and influent from a full-scale WWTP with conventional anaerobic/anoxic/aerobic (A/A/O) process over a year to explore their functionality and network differentiation. High-throughput sequencing showed that community compositions did not differ appreciably between the different tanks, likely due to the continuous sludge community interchange between tanks. However, network analysis showed significant differences in inter-species relationships, OTU topological roles, and keystone populations in the different AS communities. Moreover, the anoxic network is expected to be more unstable and easily affected by environmental disturbance. Tank-associated environmental factors, including dissolved oxygen, pH, and nutrients, were found to affect the relative abundance of functional genera (i.e., AOB, NOB, PAOs, and denitrifiers), suggesting that these groups were more susceptible to environmental variables than other bacteria. Therefore, this work could assist in improving our understanding of tank-associated microbial ecology, particularly the response of functional bacteria to seasonal variations in WWTPs employing A/A/O process.     

瑞利波法在检验复合地基效果中的应用

应用弹性波理论研究场地土物理特征,以瑞利波的基本原理与理论解释为基础,提出用瑞利波法测定场地土力学参数。该方法具有快速、经济、不受场地条件影响等特点,其成果与反映整个场地平面的原位测试结果几乎一致。实例分析说明了该法的实用性与可靠性,同时提出采用瑞利波法普查结合少数几组荷载板试验的方法,对整个场地的检测与评价将更为全面、准确和客观。     

不同菌糠生物炭对水体中Cu2+、Cd2+的吸附性能

以菌糠废弃物为原料,采用限氧裂解法在500℃条件下制备香菇菌糠、猴头菇菌糠和平菇菌糠生物炭(LEBC、HEBC和POBC).利用SEM、XRD和FTIR等方法对吸附剂进行了表征;通过吸附动力学、等温吸附、生物炭酸化实验探究了3种菌糠生物炭去除水溶液中Cu~(2+)、Cd~(2+)的效果及机理.结果表明,在溶液初始pH 2—3时,3种菌糠生物炭对溶液中Cu~(2+)、Cd~(2+)的吸附量急剧增加.LEBC、HEBC、POBC对Cu~(2+)、Cd~(2+)的吸附符合准二级动力学模型,对Cu~(2+)的吸附速率分别为10.15×10~(-3)、7.08×10~(-3)、0.69×10~(-3) mg·g~(-1)·min~(-1),对Cd~(2+)的吸附速率分别为6.53×10~(-3)、5.19×10~(-3)、0.26×10~(-3) mg·g~(-1)·min~(-1).不同浓度下LEBC、HEBC、POBC对Cu~(2+)的吸附符合Langmuir模型,最大吸附量依次为56.74、11.98、77.32 mg·g~(-1);而Cd~(2+)的吸附符合Freundlich模型,最大吸附量依次为74.26、36.49、70.2 mg·g~(-1).LEBC在较短的时间内能达到较大的吸附量,可作为去除水体中Cu~(2+)、Cd~(2+)的优质吸附剂.XRD和FTIR等分析结果表明生物炭对Cu~(2+)、Cd~(2+)的吸附机制包括物理吸附、阳离子-π作用、官能团络合及沉淀.3种生物炭经酸化处理后,对Cu~(2+)、Cd~(2+)的吸附能力显著下降,表明生物炭中碳酸盐引起的Cu~(2+)、Cd~(2+)表面沉淀在吸附过程中起重要作用.     

磷酸钙盐结晶除磷工艺性能研究

研究了主要工艺条件pH和Ca/P对磷酸钙盐结晶除磷工艺性能的影响。通过分批实验,建立了磷去除率与pH之间的指数函数关系以及磷去除率与Ca/P之间的对数函数关系。连续运试表明,在pH=9.0、Ca/P=2的条件下,磷酸钙盐结晶除磷反应器的容积负荷为1.10 kg P/(m3.d),磷去除率为51%。灵敏度分析表明,pH对磷去除率的影响大于Ca/P,将Ca/P提高至6,容积负荷提高至1.60 kg P/(m3.d),磷去除率提高至74.3%;将pH提高至10.0,容积负荷提高至1.80 kg P/(m3.d),磷去除率提高至83.5%。工艺操作上可选pH作为优先控制对象。     

Quantification of pesticide residues on plastic mulching films in typical farmlands of the North China

• Pesticide residuals on mulching film of Shandong, Tianjin and Hebei. • Detected 29 pesticides in soil and 30 in mulching film. • Pesticides on plastic films: 86.4‒22213.2 ng/g and in soil: 9.3‒535.3 ng/g. • Pesticides on plastic films 20 times higher than in soil. Plastic debris as new pollutants attracts much attention in the recent years. The plastic mulching films is one of the most important plastic debirs source in the environment. The aim of this work was to investigate the current status of pesticide residues on the plastic mulching films. Based on the QuEChERS method, multi-residue methods for detection of pesticide residues with gas chromatography tandem mass spectrum (GC-MS) and high performance liquid chromatography tandem mass spectrum (HPLC-MS) were developed for the analysis of the pesticides residues in plastic film and soil samples from Tianjin, Hebei and Shandong. The total concentrations of pesticide residues were in the range of 86.4‒22213.2 ng/g in plastic film debris, which was about 20 times higher than that in soil (9.3‒535.3 ng/g). Residual level of pesticides varied greatly in different samples. The historical usage and recent application of pesticides were the main sources for pesticide residues on plastic films and soil. In short, plastic mulching films could act as a sink for pesticides in farmland and the ubiquitous pesticide residues on plastic films should draw more attention.     

Diphenylarsinic acid sorption mechanisms in soils using batch experiments and EXAFS spectroscopy

• DPAA sorption data was found to fit the Freundlich equation. • K_f was significantly positive correlated with oxalate-extractable Fe₂O₃. • Ligand exchange was the main mechanism for DPAA sorption on soils. • Bidentate binuclear and monodentate mononuclear DPAA bonds were identified. Diphenylarsinic acid (DPAA) is a phenyl arsenic compound derived from chemical warfare weapons. Macroscopic and microscopic work on DPAA sorption will provide useful information in predicting the partitioning and mobility of DPAA in the soil-water environment. Here, batch experiments and extended X-ray absorption fine structure (EXAFS) spectroscopy were used to investigate the sorption mechanisms of DPAA. The DPAA sorption data from 11 soil types was found to fit the Freundlich equation, and the sorption capacity, K_f, was significantly and positively correlated with oxalate-extractable Fe₂O₃. The K_f values of eight of the 11 untreated soils (1.51–113.04) significantly decreased upon removal of amorphous metal (hydr)oxides (0.51–13.37). When both amorphous and crystalline metal (hydr)oxides were removed from the untreated soils, the K_f values either decreased or slightly increased (0.65–3.09). Subsequent removal of soil organic matter from these amorphous and crystalline metal (hydr)oxide-depleted samples led to further decreases in K_f to 0.02–1.38, with only one exception (Sulfic Aquic-Orthic Halosols). These findings strongly suggest that ligand exchange reactions with amorphous metal (hydr)oxides contribute most to DPAA sorption on soils. EXAFS data provide further evidence that DPAA primarily formed bidentate binuclear (²C) and monodentate mononuclear (¹V) coring-sharing complexes with As-Fe distances of 3.34 and 3.66 Å, respectively, on Fe (hydr)oxides. Comparison of these results with earlier studies suggests that ²C and ¹V complexes of DPAA may be favored under low and high surface coverages, respectively, with the formation of ¹V bonds possibly conserving the sorption sites or decreasing the steric hindrance derived from phenyl substituents.     

应用浮游植物对扎龙自然保护区水质的初步评价

通过对扎龙自然保护区水体中浮游植物调查及运用几种评价公式分析,评价结论为:扎龙水体浮游植物由8门60个属组成,数量在19 515×10~2～23 755×10~3个/升之间;水质属中污染型,同一年度污染情况为:8月>6月,北区>南区。