热解温度对污泥生物炭的表面特性及重金属安全性的影响

以一套中试干燥热解一体化处理设备,采用热解工艺,在300~600℃范围内对污水处理厂产生的剩余污泥进行了批处理,得到了系列污泥生物炭产品,并对其表面电荷、FT-IR图谱等进行了测试,对污泥及生物炭的重金属总量和DTPA可提取态进行了比较分析。研究表明,热解温度会影响生物炭表面电荷分布,而且在400℃时表面电荷分布最均匀。经热解反应后,污泥中的重金属总量虽然得到了一定程度的富集,但Pb,Zn,Cu,Fe和Mn 5种重金属的DTPA-可提取态的含量大幅度降低,因此,污泥生物炭中的重金属被惰性化,降低了环境风险。     

Why are Prices in Wild Catch and Aquaculture Industries so Different?

Through a comparative analysis of prices in capture fisheries and aquaculture sectors, the objectives of this paper are a) to investigate three the trends in prices of forage catches to feed the aquaculture species, b) to analyze the amount of fish species need to feed aquaculture species in order to assess the level of efficiency in resource use, and c) to examine the degree of economic concentration either in wild-catch industry and aquaculture sectors. The results show that prices of cultivated species are higher than prices of the same species when harvested from the sea. We explain this fact by the interplay of three forces. First, the amount of wild fish to feed aquaculture species continues to improve over time. Second, the pressure of fishing activities has not been reduced since catches of most forage fishes are declining, which induce higher prices of capture species that feed aquaculture production. Third, the level of seafood market concentration is significantly higher in aquaculture than in wild catches, which generates higher prices in aquaculture.     

Growth and photosynthetic responses to copper in wild grapevine

The present study evaluates the tolerance and accumulation potential of Vitis vinifera ssp. sylvestris under moderate and high external Cu levels. A greenhouse experiment was conducted in order to investigate the effects of a range of external Cu concentrations (0–23 mmol L⁻¹) on growth and photosynthetic performance by measuring gas exchange, chlorophyll fluorescence parameters and photosynthetic pigments. We also measured the total copper, nitrogen, phosphorus, sulphur, calcium, magnesium, iron, potassium and sodium concentrations in the plant tissues. All the experimental plants survived even with external Cu concentrations as high as 23 mmol L⁻¹ (1500 mg Cu L⁻¹), although the excess of metal resulted in a biomass reduction of 35%. The effects of Cu on growth were linked to a reduction in net photosynthesis, which may be related to the effect of the high concentration of the metal on photosynthetic electron transport. V. vinifera ssp. sylvestris survived with leaf Cu concentrations as high as 80 mg kg⁻¹ DW and growth parameters were unaffected by leaf tissue concentrations of 35 mg Cu kg⁻¹ DW. The results of our study indicate that plants of V. vinifera ssp. sylvestris from the studied population are more tolerant to Cu than the commercial varieties of grapevine that have been studied in the literature, and could constitute a basis for the genetic improvement of Cu tolerance in grapevine.     

Pharmaceuticals and personal care products found in the Great Lakes above concentrations of environmental concern

The monitoring of pharmaceuticals and personal care products (PPCPs) has focused on the distribution in rivers and small lakes, but data regarding their occurrence and effects in large lake systems, such as the Great Lakes, are sparse. Wastewater treatment processes have not been optimized to remove influent PPCPs and are a major source of PPCPs in the environment. Furthermore, PPCPs are not currently regulated in wastewater effluent. In this experiment we evaluated the concentration, and corresponding risk, of PPCPs from a wastewater effluent source at varying distances in Lake Michigan. Fifty-four PPCPs and hormones were assessed on six different dates over a two-year period from surface water and sediment samples up to 3.2 km from a wastewater treatment plant and at two sites within a harbor. Thirty-two PPCPs were detected in Lake Michigan and 30 were detected in the sediment, with numerous PPCPs being detected up to 3.2 km away from the shoreline. The most frequently detected PPCPs in Lake Michigan were metformin, caffeine, sulfamethoxazole, and triclosan. To determine the ecological risk, the maximum measured environmental concentrations were compared to the predicted no-effect concentration and 14 PPCPs were found to be of medium or high ecological risk. The environmental risk of PPCPs in large lake systems, such as the Great Lakes, has been questioned due to high dilution; however, the concentrations found in this study, and their corresponding risk quotient, indicate a significant threat by PPCPs to the health of the Great Lakes, particularly near shore organisms.     

泥石流运动饱和浓度和流量的实验研究

对泥石流饱和浓度的研究具有重要和普遍意义。目前泥石流饱和浓度的研究还不能解释泥石流运动的一些物理含义,也不能完全反映泥石流饱和和运动的浓度规律。本文通过对两种颗粒在水槽中运动的饱和浓度和流量的研究,给出了泥石流的饱和浓度计算公式。该公式有较好的物理含义,与有关的实验资料对比有较好的一致性。文中还给出了泥石流流量的计算公式,与野外资料对比,所给公式能覆盖这些野外资料数据。     

洪涝灾害灾情时间变化特性分析：以中国1736—1911年主要大江大？…

利用已经建立的全国１７３６￣１９１１年洪涝灾害时间序列,拟合各个区域的洪涝灾害长期变化趋势,并通过功率谱分析了时间序列的波动规律;同时,分析了气温、降水等自然因素的变化和人口总量变化、人口空间迁移以及土地利用变化等人文因素变化与灾害增减之间的关系。结果表明,洪涝灾害的波动主要由气候变化等自然因素的波动所引起,而人类活动增强并不断向高风险区扩展是洪涝灾害持续增长的主要原因,最终使洪涝灾害表现为波动中     

差示分光光度法在水质监测中的应用

通过测定高浓度氨氮标准品(GSBZ20005—88)的试验,验证了差示分光光度法在测定高浓度样品时的准确度和精密度,说明差示分光光度法在一定情况下能减少多次稀释所带来的误差,可以快速测定高浓度样品。     

乌鲁木齐市煤改气工程对采暖期 SO2和 NO2浓度变化的影响分析

通过对乌鲁木齐市2011-2013年采暖期SO2、NO2、PM10的年均浓度、月均浓度、日均浓度的变化比较,分析了乌鲁木齐市煤改气工程实施前后大气环境发生的变化趋势,论证了乌鲁木齐市煤改气工程对城市大气环境的改善作用,为该工程今后的推广与发展得到了可靠的实践依据。     

兰州市大气颗粒物污染特征分析

对兰州市2011—2012年大气颗粒物污染状况进行了研究,在主导风向上设置采样点,分别连续监测PM10、TSP、风速、能见度。结果表明,兰州市颗粒物浓度的峰值出现在2—4月,TSP浓度最大值可达到2.465 mg/m3,PM10最大值可达到2.079 mg/m3;颗粒物污染的季节性强,以3、4月出现的频率最高,发生时间具有随机性;2012年兰州市全年颗粒物(PM10和TSP)平均小时浓度值低于2011年,沙尘天气发生频次较2011年有所降低,环境空气质量有所改善。     

各国环境空气质量评价中污染物浓度表示方法比较

对不同国家在环境空气质量评价中主要污染物浓度表示方法进行了比较和分析,发现各国对于气态污染物浓度的表示方法主要有体积比浓度和质量浓度2种方法,对于颗粒物浓度的表示方法则普遍采用了质量浓度;颗粒物的质量浓度有标况浓度和实况浓度2种表示方法,在中国标况浓度和实况浓度的数值存在较大差异,在不同地区和不同季节此差异大小亦不同,一般情况下,实况浓度低于其标况浓度,且实况浓度能够更加客观反映颗粒物污染状况;建议修订中国环境空气质量标准中颗粒物浓度的表示方法,使用实际状况下的质量浓度来表示空气中颗粒物的浓度,以保证中国与其他国家之间监测数据的可比性。