The study of operating variables in soil washing with EDTA

This study discusses the operating variables for removal of metals from soils using EDTA, including the type of EDTA, reaction time, solution pH, dose, temperature, agitation, ultrasound and number of extractions. For As, Cd, Cu, Pb and Zn, the removal efficiency order was: H₄-EDTA > Na₂EDTA > (NH₄)₂EDTA. At low EDTA concentrations the removal increased progressively with increasing dose while above 0.4 mmol/g only small increases in extraction efficiency were observed. EDTA induced a two-step process including a rapid desorption within the first hour, and a gradual release in the following hours. The extraction efficiency of metals decreased with increasing pH in the range of 2-10. Consecutive extractions using low concentrations were more effective than a single extraction with concentrated EDTA if the same dose of EDTA was used.     

农药生产废水处理方法与资源化技术

综述了农药生产废水的常用处理方法和资源化技术 ,认为在处理废水的同时 ,应尽可能地回收和利用废水中有用物质 ;同时 ,要合理采用综合处理技术 ,以期达到最佳的处理效果     

The impact of eutrophication on the biogeochemical cycling of mercury species in a reservoir: a case study from Hongfeng Reservoir, Guizhou, China

The mercury distribution and speciation in the water column were investigated from November 2003 to September 2004. The distribution and concentrations of total mercury (THg) and particulate mercury (PHg) showed that algae had a large capacity to bind mercury in late spring (e.g. in May). It is shown that dissolved gaseous mercury (DGM) concentrations may also be affected by algae activities. The MeHg profile in the water column at a highly eutrophied site in Hongfeng Reservoir demonstrated that most of the MeHg was produced in the hypolimnion, whereas the MeHg profile pattern at another site with less eutrophication indicated that MeHg in water was largely ascribed to release from sediment. In September, the outflow of the reservoir was enriched with MeHg, which was 5.5 times higher than that in the inflows. The discharge of MeHg-concentrated water from the anoxic hypolimnion in the reservoir may pose a risk to downstream fauna.     

聚铁硅型混凝剂的形态分析及性能研究

以水玻璃和聚合硫酸铁为原料制备不同碱化度(B)及不同Fe/Si摩尔比的系列聚合硫酸铁硅混凝剂(PFSS)并对其形态进行分析。采用FeFerron逐时络合比色法发现随熟化时间延长,Fe(a)和Fe(b)的含量逐渐减少,Fe(c)的含量逐渐增多,而碱化度越大,PFSS中铁越易从Fe(a)向Fe(c)转化。采用显微电泳实验发现PFSS随着投加量增加,Zeta电位升高。采用超滤法测定了制备的PFSS分子量的分布情况,并将其与PFS进行了比较,结果发现,PFSS的分子量明显比PFS的分子大。     

遥测台网尾波持续时间震级公式探讨

本文用回归方法探讨建立用尾波持续时间τ确定震级的经验公式,以安徽省无线遥测台网的资料为例用lg~aτ和震中距Δ作为自变量,选择较佳形式。本文比较了使用τ的平均值(?)和各台各自持续时间的方法,也考虑了台站的校正值问题,最后提出了适合安徽台网的公式。M_D=0. 573lg~2τ+0. 00025Δ+0. 581+δ_i     

Environmental contamination of heavy metals from zinc smelting areas in Hezhang County, western Guizhou, China

Total heavy metal (Cd, Cr, Cu, Pb and Zn) concentrations were evaluated in smelting waste, soil, crop and moss samples collected from the Hezhang artisanal zinc smelting areas, Guizhou, China. Soil samples from the cornfield near the smelting sites contained extremely high Cd (5.8-74 mg kg(-1)), Pb (60-14,000 mg kg(-1)) and Zn (260-16,000 mg kg(-1)) concentrations. Elevated heavy metal concentrations were also found in corn plants and total Pb (0.80-1.5 mg kg(-1)) and Cd (0.05-0.76 mg kg(-1)) concentrations in corn grain have totally or partially exceeded the national guidance limits for foodstuff. Thus, the soil-to-crop transfer of heavy metals might pose a potential health risk to the local residents. Similar to the high heavy metal levels in soil and corn, Cd, Cr, Cu, Pb and Zn concentrations in moss samples collected from the smelting sites ranged from 10 to 110, 10 to 55, 26 to 51, 400 to 1200 and 330 to 1100 mg kg(-1), respectively, exhibiting a local spatial pattern of metals deposition from the atmosphere. Based on examination of Zn/Cd and Pb/Cd ratios of the analyzed samples, we have distinguished between the flue gas dust derived and smelting waste derived metals in different environmental compartments.     

珠江三角洲北江饮用水源地新污染物的非靶向筛查与生态风险评估

为探究北江饮用水源地新污染物(ECs)的时空分布特征和评估生态风险水平,采用超高效液相色谱-质谱联用技术进行1a(2022年6月至2023年5月)的非靶向筛查,并对8种典型ECs的浓度进行定量检测.结果表明:非靶向筛查共识别出346种污染物,其中工业材料、药品和农药是最主要的污染物,总共占比88.2％;8种典型ECs的检出浓度范围在n.d(未检出)～180 ng·L-1,6种检出率在80％以上,内分泌干扰物类:双酚A(BPA)、4-壬基酚(4-NP)以及农药类阿特拉津(ATZ)、异丙草胺(PPS)是其中浓度较高的污染物(中值8.12～35.58 ng·L-1);ATZ、PPS、罗红霉素(ROX)和布洛芬(IBU)春季浓度显著高于其他3个季节(P＜0.05);采样点1(S1)与采样点3(S3)的ATZ和洛美沙星(LOM)以及采样点2(S2)的4-NP生态风险水平较高(RQ＞1),4-NP和ATZ因其高检出率与较高的生态毒性,需要引起关注.由于ATZ主要来源于农业领域,其浓度水平随季节变化显著,建议在春季时期加强管控.该研究为加强对该区域ECs的认识提供了有价值的参考.     

安全投资技术经济分析的研究

在分析安全投资项目特殊性的基础上，提出了较为完整的安全投资技术经济分析方法，为企业进行安全投资决策提供了充分的依据。     

济南市大气污染防治三区划定研究

根据《山东省区域性大气污染物综合排放标准》(DB37/2376-2013)实施要求,开展济南市市域范围大气污染防治三区划定。划定过程以地理信息系统空间分析技术为手段,根据各区域大气环境承载力、人口密度分布和生态环境敏感程度三个因素的空间分布差异,实现三区划分,形成划定初步方案。同时,结合相关规划和重点企业/工业园区空间布局状况,对初步划定方案进行调整,形成三区划定最终方案,并在此基础上提出各分区大气污染控制措施。