Distribution of elements in needles of Pinus massoniana (Lamb.) was uneven and affected by needle age

Macronutrients (P, S, K, Na, Mg, Ca), heavy metals (Fe, Zn, Mn, Cu, Pb, Cr, Ni, Cd,) and Al concentrations as well as values of Ca/Al in the tip, middle and base sections, and sheaths of current year and previous year needles of Pinus massoniana from Xiqiao Mountain were analyzed and the distribution patterns of those elements were compared. The results indicated that many elements were unevenly distributed among the different components of needles. Possible deficiency of P, K, Ca, Mn and Al toxicity occurred in needles under air pollution. Heavy metals may threaten the health of Masson pine. Needle sheaths were good places to look for particulate pollutants, in this case including Fe, Cu, Zn, Pb, Cr, Cd and Al.     

Heavy metals in bark of <Emphasis Type="Italic">Pinus massoniana</Emphasis> (Lamb.) as an indicator of atmospheric deposition near a smeltery at Qujiang,China

Goal, Scope and Background Rapid urbanization and the expansion of industrial activities in the past several decades have led to large increases in emissions of pollutants in the Pearl River Delta of south China. Recent reports have suggested that industrial emission is a major factor contributing to the damages in current natural ecosystem in the Delta area. Tree barks have been used successfully to monitor the levels of atmospheric metal deposition in many areas, but rarely in China. This study aimed at determining whether atmospheric heavy metal deposition from a Pb-Zn smeltery at Qujiang, Guangdong province, could be accurately reflected both in the inner bark and the outer bark of Masson pine (Pinus massoniana L.). The impact of the emission from smeltery on the soils beneath the trees and the relationships of the concentrations between the soils and the barks were also analyzed. Methods Barks around the bole of Pinus massoniana from a pine forest near a Pb-Zn smeltery at Qujiang and a reference forest at Dinghushan natural reserve were sampled with a stainless knife at an average height of 1.5 m above the ground. Mosses and lichens on the surface barks were cleaned prior to sampling. The samples were carefully divided into the inner bark (living part) and the outer bark (dead part) in the laboratory, and dried and ground, respectively. After being dry-ashed, the powder of the barks was dissolved in HNO₃. The solutions were analyzed for iron (Fe), manganese (Mn), copper (Cu), zinc (Zn), chromium (Cr), nickel (Ni) and cobalt (Co) by inductively coupled plasmas emission spectrometry (ICP, PS-1000AT, USA) and Cadmium (Cd) and lead (Pb) by graphite furnace atomic absorption spectrometry (GFAAS, ZEENIT 60, Germany). Surface soils (0–10 cm) beneath the sample trees were also collected and analyzed for the selected metals. Results and Discussion Concentrations of the selected metals in soils at Qujiang were far above their environmental background values in the area, except for Fe and Mn, whilst at Dinghushan, they were far below their background values, except for Cd and Co. Levels of the metals, in particular Pb and Zn, in the soils beneath the sample trees at Qujiang were higher than those at Dinghushan with statistical significance. The result suggested that the pine forest soils at Qujiang had a great input of heavy metals from wet and dry atmospheric deposition, with the Pb-Zn smeltery most probably being the source. Levels of Cu, Fe, Mn, Zn, Ni and Pb at Qujiang, both in the inner and the outer bark, were statistically higher than those at Dinghushan. Higher concentrations of Pb, Fe, Zn and Cu may come from the stem-flow of elements leached from the canopy, soil splash on the 1.5 m height and sorption of metals in the mosses and lichens growing on the bark, which were direct or indirect results from the atmospheric deposition. Levels of heavy metals in the outer barks were associated well with the metal concentrations in the soil, reflecting the close relationships between the metal atmospheric deposition and their accumulation in the outer bark of Masson pine. The significant (p<0.01) correlations of Fe-Cu, Fe-Cr, Fe-Pb, Fe-Ni, Pb-Ni, and Pb-Zn in the outer barks at Qujiang again suggested a common source for the metals. The correlation only occurred between Pb and Ni, Cd and Co in the outer barks at Dinghushan, which suggested that those metals must possibly have other uncommon sources. Conclusions Atmospheric deposition of the selected metals was great at Qujiang, based on the levels in the bark of Pinus massoniana and on the concentrations in the soils beneath the trees compared with that at Dinghushan. Bark of Pinus massoniana, especially the outer bark, was an indicator of metal loading at least at the time of sampling. Recommendations and Perspectives The results from this study and the techniques employed constituted a new contribution to the development of biogeochemical methods for environmental monitoring particularly in areas with high frequency of pollution in China. The method would be of value for follow up studies aimed at the assessment of industrial pollution in other areas similar with the Pearl River Delta.     

Highly efficient conversion of sugarcane bagasse pretreated with liquid hot water into ethanol at high solid loading

Liquid hot water (LHW), an environmental-friendly physico-chemical treatment, was applied to pretreat the sugarcane bagasse (SCB). Tween80, a non-ionic surfactant, was used to enhance the enzymatic hydrolysis of the pretreated SCB. It found that 0.125 mL Tween80 /g dry matter could make the maximum increase (33.2%) of the glycan conversion of the LHW-pretreated SCB. A self-designed laboratory facility with a plate-and-frame impeller was applied to conduct batch hydrolysis, fed-batch hydrolysis, and the process of high-temperature (50°C) fed-batch hydrolysis following low-temperature (30°C) simultaneous saccharification and fermentation (SSF) which was adopted to overcome the incompatible optimum temperature of saccharification and fermentation in the SSF process. After hydrolyzing LHW-pretreated SCB for 120 h with commercial cellulase, the total sugar concentration and glycan conversion obtained from fed-batch hydrolysis were 91.6 g/L and 68.3%, respectively, which were 9.7 g/L and 7.3% higher than those obtained from batch hydrolysis. With Saccharomyces cerevisiae Y2034 fermenting under the non-sterile condition, the ethanol production and theoretical yield obtained from the process of SSF after fed-batch hydrolysis were 55.4 g/L and 88.3% for 72h, respectively, which were 15.5 g/L and 24.7% higher than those from separate fed-batch hydrolysis and fermentation. The result of this work was superior to the reported results obtained from the LHW-pretreated SCB.     

Fe~(3+)和Cu~(2+)对饮用水氯消毒副产物三卤甲烷形成的影响

为了研究水中存在Br-的情况下,Fe3+和Cu2+对三卤甲烷(THMs)的生成及CHCl3、CHBr Cl2、CHBr2Cl、CHBr34种消毒副产物相对分布的影响,以腐殖酸模拟氯消毒过程中的前体物进行实验。结果表明,在p H为6、7和9 3种条件下,Fe3+抑制了THMs的生成,p H=6时只有CHCl3生成量随着Fe3+浓度的增加逐渐减少,其余3种消毒副产物均在增加,p H=7时4种消毒副产物浓度均减小并在Fe3+浓度为2 mg/L时生成量最低,p H=9时的生成趋势与p H=6时类似。Cu2+能促进THMs的生成,在p H为6、7和9时,当加入0.5 mg/L Cu2+时,THMs总量分别增加了16.7%、22.6%和2.5%,随着p H增加,THMs总量增加。在3种p H环境中,Cu2+对THMs生成的影响大于Fe3+,在偏酸性环境中,Fe3+影响THMs生成,产生的致癌风险高,当金属离子浓度为2.5 mg/L时,致癌风险相差最高为15%,在中性和偏碱性环境中,Cu2+影响THMs生成,产生的致癌风险高。     

不同培养条件下锰过氧化物酶(MnP)的合成及其对甲基橙的降解

高效、大规模、低成本合成木质素降解酶是直接采用其降解难降解有机污染物所必须解决的问题.对锰过氧化物酶(MnP)降解甲基橙和在非灭菌的反应器中连续合成MnP的可行性进行考察.结果表明,在采用2 mmol H2O2和1.5 mmol MnSO4的降解体系中,获最大脱色效果,且100、200和300 U/L的MnP可在8h内将甲基橙分别脱色18％、23％和35％;在非灭菌的反应器水平上实现了固定化培养的P.chrysosporium连续23 d合成MnP,但MnP酶活仅为2～ 23 U/L,难以酶解甲基橙;然而,在摇瓶培养条件下固定化的P.chrysosporium合成的MnP却能达1 152 U/L.因此,直接采用MnP对污染物进行降解以及在非灭菌的反应器中持续合成MnP是可行的,但就在非灭菌条件下如何提高MnP的合成量还有待开展深入的研究.     

赤泥制备含钛聚硅酸铝铁及亚甲基蓝溶液的混凝脱色

以拜耳法赤泥为原料、Na Cl为助溶剂,采用酸浸法溶出赤泥中的铁、铝元素,再与硅酸钠、硫酸氧钛反应制备出高效混凝剂含钛聚硅酸铝铁(T-PSAF),并将其用于模拟亚甲基蓝印染废水的脱色。实验结果表明:在硫酸浓度为8 mol/L、液固比(硫酸体积与干赤泥质量之比)为14 m L/g、酸浸温度为80℃、酸浸时间为80 min、Na Cl加入量为0.10 g/g(以干赤泥计)的优化酸浸条件下,铁、铝的浸出率分别为88.25%和73.21%;在n(Fe+Al)∶n(Ti)∶n(Si)=0.3∶0.3∶1、熟化p H为4~5、熟化时间为2 h、混凝剂加入量为25 m L/L的优化混凝条件下,初始亚甲基蓝质量浓度为10 mg/L的废水的脱色率可达87.1%,而当初始亚甲基蓝质量浓度增至150~200 mg/L时废水脱色率可达99%以上。     

Investigation of PM2.5 pollution during COVID-19 pandemic in Guangzhou, China

The COVID-19 pandemic has raised awareness about various environmental issues,including PM_2.5 pollution.Here,PM_2.5 pollution during the COVID-19 lockdown was traced and analyzed to clarify the sources and factors influencing PM_2.5 in Guangzhou,with an emphasis on heavy pollution.The lockdown led to large reductions in industrial and traffic emissions,which significantly reduced PM_2.5 concentrations in Guangzhou.Interestingly,the trend of PM_2.5     

复合污染状态下尾矿区有害化学品的迁移研究

用混合尾矿浆及尾矿渣淋溶柱,研究选矿药剂在尾矿渣及尾矿废水中的静态分布及其淋溶作用,结果表明:①选矿药剂对整个尾矿区都污染,即使是水溶性好的药剂,它们在尾矿渣中的静态分布也占有相当的比例,油溶性好的药剂多存在于尾矿渣中,尾矿污染为多种药剂的复合污染,各种药剂在尾矿渣及尾矿废水中的总浓度成倍加大;②用尾矿渣淋溶柱测得单一药剂的淋溶值:25号黑药>MIBC> CN->二号油>乙基黄药>丁基黄药>Y-89黄药.但多种药剂复合污染时,药剂的淋溶距离明显加大,其中CN-和Y-89黄药加大近一倍.复合药剂污染加大药剂的残留期,也加大它们向地下水及其它水源迁移的几率.     

多功能粉煤灰治理垃圾场渗滤液

以具絮凝、吸附、降解多功能粉煤灰污水处理材料,填充成絮凝沉降降解过滤箱,组合有鼓气、臭氧的连续式5级垃圾场渗滤液集成处理系统。垃圾渗滤液流量、鼓气量、臭氧量分别为40Lh、40L(m3·h)、15mgL的工艺条件下,渗滤液的悬浮物、色度、CODCr、BOD5、氨氮、硫化物等主要污染物指标分别降低93%、90%、96%、92%、86%和92%,达到垃圾场渗滤液二级控制标准。