氢氧化镁-壳聚糖复合絮凝剂对印染废水的脱色研究

使印染废水脱色是废水处理的重要问题,利用无枳／有机复合絮凝剂可取得优良的脱色效果。采用氢氧化镁一壳聚糖复合絮凝剂对印染废水进行脱色处理,研究了pH值、壳聚糖投加量、复合絮凝剂加入量等对脱色效果的影响。结果表明氢氧化镁一壳聚糖复合絮凝剂比单独使用氢氧化镁絮凝剂脱色效果好。壳聚糖是一种天然高分子化合物,是甲壳素的脱乙基产物。来源丰富,且具有无毒副作用、易降解等优点。利用壳聚糖作为复配剂制备的复合絮凝减少了镁盐的使用量,有效降低了废水处理成本,避免引起二次污染。     

论述造纸行业控制可吸附有机卤化物的必要性

造纸业漂白过程会带来可吸附有机卤化合物的污染,这是一类含有包括二恶英在内的多种有毒有机物。随着全球贸易进程,控制造纸业可吸附有机卤化合物的排放已经刻不容缓。控制造纸行业可吸附有机卤化物应从工艺技术、排放标准执行、监测等方面着手。     

关于灾害管理学的几点想法

随着社会经济的发展,我国各种自然灾害的发生有规模大、损失严重的趋势,加强灾害管理对于建立和谐社会意义重大.本文在总结前人工作的基础上,阐述了灾害管理的含义、灾害管理系统的自组织性和协同性,概括了灾害管理的一般方法,指出灾害管理是发展管理.     

Distribution and temporal trends of butyltins monitored by molluscs along the Chinese Bohai coast from 2002 to 2005

Thirteen areas around the Chinese Bohai coast, individuals including ten kinds of bivalves and two kinds of snails were collected during the period of 2002-2005 for the investigation of spatial distribution and temporal variations of butyltin compounds (BTs). BTs including tributyltin (TBT) and its derivates, dibutyltin (DBT) and monobutyltin (MBT) were quantified by gas chromatography/flame photometric detection after extraction and Grignard derivatization. BTs compounds were widely existed in the samples and TBT was the dominant composition, indicating recent TBT input along Bohai coast. As a whole, BTs concentration remained high during the sampling years except a slightly decreased in samples from several sites in 2005. The contamination characteristics of BTs in different sampling sites were analyzed using principal component analysis (PCA) method, and the species specific bioaccumulation of BTs was also identified using cluster analysis.     

The spatial-temporal differentiation of green land use in Beijing–Tianjin–Hebei urban agglomeration

ABSTRACT

As the space carrier of the construction of ecological civilization, land’s green and efficient utilization is an important guarantee for realizing national sustainable development. Based on traditional land evaluation, this paper scientifically defines the green land use, puts land as one of the production factors, and brings energy consumption, environmental pollution, etc. into the input-output system to measure the green land utilization efficiency of the urban construction land of Beijing-Tianjin-Hebei Urban Agglomeration from 2006 to 2016. The study shows that the overall efficiency variation of the urban agglomeration is related with the land and environment policies. Efficiency of 2016 is higher than that of 2006, and energy and environment are the principal factors affecting the green land use. The efficiency of each city is positively correlated with its economic development, negatively correlated with the construction land expansion. Efficiency gaps in different cities are expanding. There is positive correlation with overall weak space between cities, and the partial spatial agglomeration phenomenon appears. Therefore, the green land use efficiency could be improved by improving land utilization efficiency, coordinating economic growth of construction land utilization with environmental protection and taking feasible ways to transregional renovation of the stock ecological land utilization, etc.     

新民居建设中农村环境教育的发展思路

新民居建设是建设社会主义新农村的重要举措,发展农村环境教育能有效促进农村环境的改善。我国农村环境教育目前存在重视程度不够、教育主体和方式相对单一以及缺乏必要的教育目标等问题。在发展农村环境教育方面明确受教育的主体,并从扩大教育实施主体、开展直接教育和间接教育以及增加政府财经投入等方面入手,才能实现经济发展与农村环境改善的协调发展。     

沼液对甘蓝连作土壤生物学性质的影响

以施用化肥225 kg/hm2为对照,设置两种不同的沼液用量(以纯氮计):沼液I(168 kg/hm2)和沼液II(225 kg/hm2),通过连续3 a的甘蓝种植试验,研究沼液对甘蓝连作土壤微生物区系、土壤酶活性以及土壤养分与土壤酶活性之间的相关性.结果表明:1)施用沼液显著改善了连作土壤的微生物区系,溶磷细菌、解钾细菌、氨化细菌、固氮菌和放线菌的数量显著增加;同时抑制了真菌的富集.两种不同用量的沼液处理较化肥处理的土壤细菌/真菌(B/F)值分别提高了142.7%和202.3%.2)在225 kg/hm2等氮水平下,施用沼液显著提高了土壤的蔗糖酶、磷酸酶和蛋白酶活性,较之化肥处理分别提高了63.96%、137.61%和139.66%;同时显著降低了土壤过氧化氢酶和多酚氧化酶活性.3)土壤养分与土壤酶活性相关性分析表明,有机质含量与土壤脲酶、磷酸酶、蔗糖酶和蛋白酶活性呈显著正相关,与过氧化氢酶活性呈显著负相关,而与多酚氧化酶活性无明显相关性;磷酸酶活性与土壤速效磷含量呈显著正相关;蛋白酶活性与土壤碱解氮、全氮含量呈显著正相关.表4参24     

Occurrence and behaviour of nonylphenol and octylphenol in Nanming River, Guiyang City, China

Occurrence, variation and behaviour of nonylphenol (NP) and octylphenol (OP) were studied in surface water and groundwater in Guiyang, Guizhou Province, southwestern China. Discharge of wastewater from Guiyang City was the main source of alkylphenols (APs) entering the aquatic environment. The concentrations of NP and OP in river water ranged from 40 to 1582 ng L(-1) and from below the lowest limit of detection (LOD) to 67 ng L(-1), respectively. NP and OP were also detected in groundwater. Both NP and OP exhibited spatial and temporal variations in river water and groundwater. It was found that concentrations of NP and OP in river water was low upstream and dramatically increased downstream, and higher concentration of NP was found in winter compared to that in summer. Proportions of NP and OP were trapped by suspended particulate matter (SPM), which accounted for 7.6-50.0% and 3.4-25.6% of their total concentration in the river water system, respectively. Seasonal changes in water flow were responsible for the temporal variations of APs. To determine the behaviour of APs along the river, a mass balance equation based on chloride was used. The results showed that a mixing process was the predominant factor to determine upstream APs concentrations; while the discharge of wastewater controlled the concentrations of APs downstream. Considering the adverse effect of APs on organisms, combined effect modeling was used to assess the toxicity to fish. It was found that the predicted mixture effect for APs in river water on fish vitellogenin induction was low upstream and medium downstream, respectively.     

Incidence of organochlorine pesticides in soils of Shenzhen, China

To determine the incidence of organochlorine pesticides (OCPs) in soil in a rapid urbanization region, soil samples from various land use types in Shenzhen were collected in winter, 2007. The concentration of dichlorodiphenyltrichloroethanes (DDTs) and hexachlorocyclohexanes (HCHs) ranged from non-detected to 149 ng g(-1) and 19 to 88 ng g(-1), respectively. The highest levels of OCPs were observed in soil from traffic and industry areas, reflecting that intensive human disturbance make the soil pollution accumulation more disperse. HCHs and DDTs profiles revealed that the sources were associated mainly with lindane and technical DDTs, respectively, while HCHs in the soil of Shenzhen might originate from both recent and historical sources. The loss of OCPs by soil erosion will enter surface runoff and impose impact on the water environment. Non-dietary exposure estimation indicates that children were the most sensitive group. The average daily exposure to OCPs for males was more serious than for females. Non-dietary exposure to DDTs and HCHs in residential blocks of Shenzhen were far below the acceptable daily intake recommended by the Food and Agriculture Organization/World Health Organization.