努鲁儿虎贫困山区生态环境综合治理方略探讨

努鲁儿虎贫困山区虽经多年治理,生态环境仍恶化,严重地制约当地经济的发展。为改善生态环境,必须正视本区缺粮食、缺资本、缺人才的区情,绿化工程建设必须紧紧围绕解决当地人民脱贫致富这一中心才有生命力,才有持久的后劲;必须营造适合当地具有生态经济效益的树(草)种;必须坚持谁种谁有,谁经营谁得利的政策;必须改变以往造林中“输血”型投资,为“造血”型投资等一系列方略。     

Personal exposure to PM2.5-bound heavy metals associated with cardiopulmonary function in general population

Environmental Science and Pollution Research - To better understand the cardiopulmonary alterations associated with personal exposed PM2.5-bound heavy meals, we conducted a cross-sectional study in...     

Linear regression with Type I interval- and left-censored response data

Laboratory analyses in a variety of contexts may result in left- and interval-censored measurements. We develop and evaluate a maximum likelihood approach to linear regression analysis in this setting and compare this approach to commonly used simple substitution methods. We explore via simulation the impact on bias and power of censoring fraction and sample size in a range of settings. The maximum likelihood approach represents only a moderate increase in power, but we show that the bias in substitution estimates may be substantial.     

利用水泥处理垃圾渗滤液生物处理出水的研究

利用水泥的表面吸附和水化反应性质处理垃圾渗滤液生物处理出水可以取得很好的效果,COD的去除率可达69.5%.处理效果与水灰比、反应时间密切相关,低水灰比和较长反应时间对COD的去除更为有利.对处理前后水样的COD和TOC分析表明,水泥对非TOC贡献的COD有很强的去除效果.     

Integrated water resources management for emergency situations: A case study of Macau

Integrated urban water management (IUWM) is a useful tool that can be used to alleviate water resource shortages in developing regions like Macau, where 98% of the raw water comes from mainland China. In Macau, scarce water resources deteriorate rapidly in emergency situations, such as accidental chemical spills upstream of the supply reservoir or salty tides. During these times, only the water from the two freshwater reservoirs in Macau can be used. In this study, we developed urban water management optimization models that integrated the raw water supply from the two reservoirs with various proposed governmental policies (wastewater reuse, rainwater collection, and water saving). We then determined how various water resource strategies would influence the urban water supply in Macau in emergency situations. Our results showed that, without imported raw water, the water supply from only the two Macau reservoirs would last for 7.95 days. However, when all the government policies were included in the model, the supply could be extended to 13.79 days. Out of the three non-conventional water resources, wastewater reuse is the most beneficial for increasing the Macau water supply, and rainwater collection also has great potential.     

氯化汞对小鼠睾丸生殖细胞的DNA损伤作用

探索氯化汞对雄性小鼠生殖细胞毒性的分子遗传机制。分别以 0 .0 1、0 .10、1.0 0 mmol/L的氯化汞体外处理小鼠睾丸细胞和以 0 .5、1.0、5 .0 μmol/kg的氯化汞体内暴露小鼠 ,应用单细胞凝胶电泳技术检测生殖细胞 DNA的损伤。体外处理 3种剂量组小鼠睾丸生殖细胞 DNA损伤率显著高于阴性对照组 ( 0 mmol/L组 ,P<0 .0 0 1) ;0 .1、1.0 mmol/L剂量组慧星细胞迁移率显著高于阴性对照组 ( P<0 .0 0 1,P<0 .0 5 )。体内暴露 3种浓度氯化汞组小鼠睾丸生殖细胞 DNA损伤率显著高于阴性对照组 ( 0μmol/kg,P<0 .0 0 1) ,5 .0 μmol/kg组慧星迁移率显著高于阴性对照组 ( P<0 .0 5 )。一定剂量的氯化汞处理引起生殖细胞 DNA损伤作用可能是氯化汞细胞毒性的机制之一。     

A new prediction method of industrial atmospheric pollutant emission intensity based on pollutant emission standard quantification

● Established a quantification method of pollutant emission standard. ● Predicted the SO₂ emission intensity of single coking enterprises in China. ● Evaluated the influence of pollutant discharge standard on prediction accuracy. ● Analyzed the SO₂ emissions of Chinese provincial and municipal coking enterprises. Industrial emissions are the main source of atmospheric pollutants in China. Accurate and reasonable prediction of the emission of atmospheric pollutants from single enterprise can determine the exact source of atmospheric pollutants and control atmospheric pollution precisely. Based on China’s coking enterprises in 2020, we proposed a quantitative method for pollutant emission standards and introduced the quantification results of pollutant emission standards (QRPES) into the construction of support vector regression (SVR) and random forest regression (RFR) prediction methods for SO₂ emission of coking enterprises in China. The results show that, affected by the types of coke ovens and regions, China’s current coking enterprises have implemented a total of 21 emission standards, with marked differences. After adding QRPES, it was found that the root mean squared error (RMSE) of SVR and RFR decreased from 0.055 kt/a and 0.059 kt/a to 0.045 kt/a and 0.039 kt/a, and theR² increased from 0.890 and 0.881 to 0.926 and 0.945, respectively. This shows that the QRPES can greatly improve the prediction accuracy, and the SO₂ emissions of each enterprise are highly correlated with the strictness of standards. The predicted result shows that 45% of SO₂ emissions from Chinese coking enterprises are concentrated in Shanxi, Shaanxi and Hebei provinces in central China. The method created in this paper fills in the blank of forecasting method of air pollutant emission intensity of single enterprise and is of great help to the accurate control of air pollutants.     

Incorporating sorption/desorption of organic pollutants into river water quality model

Preliminary research was conducted about how to incorporate sorption/desorption of organic pollutants with suspended solids and sediments into single-chemical and one-dimensional water quality model of Jinghang Canal.Sedimentation-resuspension coefficient k3 was deduced; characteristics of organic pollutants, concentrations and components of suspended solids/sediments and hydrological and hydraulic conditions were integrated into k3 and further into river water quality model; impact of sorption/desorption of organic pollutants with suspended solids and sediments on prediction function of the model was discussed. Results demonstrated that this impact is pronounced for organic pollutants with relatively large Koc and Kow, especially when they are also conservative and foc of riversuspended solids/sediments is high, and that incorporation of sorption/ desorption of organic pollutants into river water quality model can improve its prediction accuracy.     

酰胺类除草剂对铜绿微囊藻的生长影响及氧化损伤效应

酰胺类除草剂的广泛使用对水生生态环境构成了潜在风险。为探究其对藻类的毒性作用,以铜绿微囊藻为对象,分别从藻类生长和氧化损伤效应角度探讨了甲草胺、乙草胺和丁草胺对铜绿微囊藻的毒性影响。实验结果显示,酰胺类除草剂对藻类的影响存在明显的滞后效应和剂量–效应关系,低浓度暴露组刺激藻类增长,高浓度表现为抑制作用;3种酰胺类除草剂增加了铜绿微囊藻的氧化压力,并随着暴露时间的延长和浓度的增加而增强。其中,藻体内过氧化脂质降解产物丙二醛(MDA)含量明显增加,同时超氧化物歧化酶(SOD)和过氧化物酶(POD)活性也显著增强。经96 h暴露后,甲草胺(32.0 mg·L~(-1))、乙草胺(32.0 mg·L~(-1))和丁草胺(15.0 mg·L~(-1))暴露溶液中相对MDA含量分别为138%、204%和154%,相对SOD活性分别为116%、87%和115%,相对POD活性分别475%、278%和627%。结合生物量及氧化损伤效应实验结果可知,3种除草剂对铜绿微囊藻的毒性大小顺序为丁草胺乙草胺甲草胺。     

Indicating landfill stabilization state by using leachate property from Laogang Refuse Landfill

Variation and evolution process of leachate can be applied as a reference for landfill stabilization phase. In this work, leachates with different ages were collected from Laogang Refuse Landfill, and characterized with 14 key parameters. Simultaneously, principal component analysis （PCA） was applied to develop a synthetic parameter-F based on these 14 parameters, and a logarithm equation was simulated for the landfill stabilization process finally. It was predicted that leachates would meet Class I and Class II in standard for pollution control on the landfill site of municipal solid waste （GB 16889-1997） after 32 years and 22 years disposal under the natural attenuation in the humid and warm southern areas of China, respectively. The predication of landfill state would be more accurate and useful according to the synthetic parameter F of leachate from a working landfill.