Evolution of China’s water issues as framed in Chinese mainstream newspaper

There is an urgent need globally to trigger fundamental societal changes in water management away from existing unsustainable paradigms. This paper attempts to understand the evolution of newspaper coverage of water issues in China by analyzing water-related articles in a major national newspaper, the People’s Daily, over the period 1946–2012 using a content analysis approach. The major findings include the following: (1) water issues were in relatively prominent positions in the newspaper; (2) the reporting of water issues in China experienced three stages: 1946 to the middle of 1980s—flood and drought control and water for food production, the middle of 1980s to 1997—water for economic development, and 1998 to the present—water for the environmental sustainability and economic development; (3) the reporting of water issues in the People’s Daily clearly reflected China’s top-down water resources management system, and no “real” public opinions on water were reported during the study period; and (4) the People’s Daily is just a wind vane of Chinese mainstream values and policies on water. The findings supported the realist assumption that the societal value changes on water issues in China were triggered by a range of factors including biophysical pressure (floods and droughts), political campaign (the Cultural Revolution), macro-economic reform (Reform and Opening-up), water institutional arrangement (the Water Law), and water management reform (the No. 1 Central Document on water reform). While there are similarities and differences between this study and other studies, important implications for more sustainable water management are a need to strengthen academic specialists’ and NGO’s voices in the newspaper to create a better informed public, and to stimulate practices toward sustainable water use.     

Accumulation of Cr,Cd, Pb,Cu, and Zn by plants in tanning sludge storage sites: opportunities for contamination bioindication and phytoremediation

Tanning sludge enriched with high concentrations of Cr and other metals has adverse effects on the environment. Plants growing in the metalliferous soils may have the ability to cope with high metal concentrations. This study focuses on potentials of using native plants for bioindication and/or phytoremediation of Cr-contaminated sites. In the study, we characterized plants and soils from six tanning sludge storage sites. Soil in these sites exhibited toxic levels of Cr (averaged 16,492 mg kg^?1) and other metals (e.g., 48.3 mg Cu kg^?1, 2370 mg Zn kg^?1, 44.9 mg Pb kg^?1, and 0.59 mg Cd kg^?1). Different metal tolerance and accumulation patterns were observed among the sampled plant species. Phragmites australis, Zephyranthes candida, Cynodon dactylon, and Alternanthera philoxeroides accumulated moderate-high concentrations of Cr and other metals, which could make them good bioindicators of heavy metal pollution. High Cr and other metal concentrations (e.g., Cd and Pb) were found in Chenopodium rubrum (372 mg Cr kg^?1), Aster subulatus (310 mg Cr kg^?1), and Brassica chinensis (300 mg Cr kg^?1), being considered as metal accumulators. In addition, Nerium indicum and Z. candida were able to tolerate high concentrations of Cr and other metals, and they may be used as preferable pioneer species to grow or use for restoration in Cr-contaminated sites. This study can be useful for establishing guidelines to select the most suitable plant species to revegetate and remediate metals in tanning sludge-contaminated fields.     

超声辅助乳化液相微萃取分析绿茶饮料和番茄汁中有机磷农药残留

农药施用于田间,必然会残留于环境中。农药残留的分析方法多种多样。为探究灵敏度高、重现性好的样品前处理方法,建立了超声辅助乳化液相微萃取,结合气相色谱和火焰光度检测器测定绿茶饮料和番茄汁中5种有机磷农药的方法,对萃取条件进行了优化,如萃取溶剂种类和体积、超声频率和时间、盐效应。在优化后的萃取条件下,5种有机磷农药实现良好分离,空白添加实验结果表明在0.1~10μg·L-1之间,线性相关系数在0.9985~0.9994之间,检测限在0.005~0.020μg·L-1之间,相对标准偏差(n=5)在4.3%~9.4%之间。在绿茶饮料和番茄汁实际样本检测中,目标分析物含量均低于检出限。样本添加回收试验的回收率均大于88.5%,相对标准偏差(n=3)在2.2%~9.8%之间,结果表明该方法用于液体样本中农药残留检测真实可靠。     

土地资源错配及经济效率损失研究

长期以来,政府主导下的土地资源配置模式为中国的城镇化、工业化快速发展提供了强有力的支撑,但同时也伴随着土地制度和政策不完善引致的土地资源配置扭曲,不同用地单位之间土地资源配置效率差异较大,不同用地单位之间的土地资源错配致使总体经济效率损失巨大。调研组通过实地随机抽样问卷调查,获取了四大产业不同类型的607个样本企业生产经营活动相关的投入产出数据,基于C-D生产函数理论,构建土地资源配置及经济效率损失测度模型,测算不同类型企业的土地资源要素错配程度及由此导致的经济效率损失。测算结果显示,环保、生物和高端装备制造产业的土地资源要素投入的相对扭曲系数都大于1,光电子信息产业系数小于1;土地资源错配造成光电子信息产业总体上经济效率损失达10.23%,高端装备制造产业达13.82%,生物产业和环保节能产业都超过了20%。研究表明,不同类型企业之间的土地资源要素投入对企业总体经济产出的贡献率存在显著差异性;同类型企业的土地资源要素配置的相对扭曲系数不同,即土地资源的错配程度不同;从用地规模大小角度分析,同类型企业用地规模大的土地资源要素的相对扭曲系数要明显高于用地规模小的企业,用地规模越大土地资源错配程度越严重;从土地资源错配造成企业经济效率损失测算结果来看,土地资源要素投入相对扭曲系数越大的企业,土地资源错配导致总体经济效率损失越大;在各类型企业的技术和规模效率不变的条件下,不增加资源要素投入,通过纠正企业的土地资源错配,能够有效地提升企业的经济效率。     

污泥热解气化技术的研究进展

通过热解气化等热化学转化方式将污泥转变为液体或气体燃料是极具前景的污泥利用方式之一。从污泥的资源化利用方面着手,阐述了污泥热解气化技术的研究进展,分析了现有污泥热解气化工艺的优缺点和主要影响因素,并对该技术的发展趋势进行了展望。指出:高湿污泥与生物质混合进行共热解可以提高原料的转化率和整个系统的热效率;高效污泥热解气化装置的研发是目前污泥热解气化技术领域亟待解决的问题。     

Historical trend of nitrogen and phosphorus loads from the upper Yangtze River basin and their responses to the Three Gorges Dam

Excessive inputs of nitrogen and phosphorus (N and P) degrade surface water quality worldwide. Impoundment of reservoirs alters the N and P balance of a basin. In this study, riverine nutrient loads from the upper Yangtze River basin (YRB) at the Yichang station were estimated using Load Estimator (LOADEST). Long-term load trends and monthly variabilities during three sub-periods based on the construction phases of the Three Gorges Dam (TGD) were analyzed statistically. The dissolved inorganic nitrogen (DIN) loads from the upper YRB for the period from 1990 to 2009 ranged from 30.47?×?10⁴ to 78.14?×?10⁴ t, while the total phosphorus (TP) loads ranged from 2.54?×?10⁴ to 7.85?×?10⁴ t. DIN increased rapidly from 1995 to 2002 mainly as a result of increased fertilizer use. Statistics of fertilizer use in the upper YRB agreed on this point. However, the trend of the TP loads reflected the combined effect of removal by sedimentation in reservoirs and increased anthropogenic inputs. After the TGD impoundment in 2003, decreasing trends in both DIN and TP loads were found. The reduction in DIN was mainly caused by ammonium consumption and transference. From an analysis of monthly loads, it was found that DIN had a high correlation to discharges. For TP loads, an average decrease of 4.91 % in October was found when the TGD impoundment occurred, but an increase of 4.23 % also occurred in July, corresponding to the washout from sediment deposited in the reservoir before July. Results of this study revealed the TGD had affected nutrient loads in the basin, and it had played a role in nutrient reduction after its operation.     

Origin and vertical variation of the bound fatty acids in core sediments of Lake Dianchi in Southwest China

Based on the molecular distribution of bound fatty acid (BFA) compound classes in core sediments of Lake Dianchi combined with the compound-specific δ¹³C values of the straight-chain BFAs, origin and vertical changes of organic matters in the sediments were investigated. The results indicated a significant change of BFA sources over the past 700 years. Contrast to the low concentrations of the terrestrial BFAs, the abundance of BFAs derived from the plankton/bacteria in the top sections (1944–recent) was more than 80 %. The increasing proportions of the branched and unsaturated BFAs in total fatty acids were closely correlated with the heavy eutrophication and the frequent algal blooms in the decades. Furthermore, the positive shift of δ ¹³C of C16 and C18 (~2?‰) in the upper section might be an indicator of the excess phytoplankton productivity. However, it was found that the plankton/bacteria-derived BFAs were more easily degraded during the early diagenetic process. The special compound carbon isotopic compositions of the long straight-chain BFAs (C24 and C26) in the sediments showed a depletion of heavier δ ¹³C values (ca. ?30?‰) in the midsections (1559–1787), reflecting a relatively growing contribution of C3 plants to C4 plants or that C4 plant growth was inhibited in cold and arid climates during the period.     

Citrobacter sp. CK3对活性红KN-3B的脱色反应动力学研究

采用脱色菌Citrobacter sp. CK3,以活性红KN-3B染料为处理对象,在厌氧批式反应条件下,系统考察了pH值,温度和染料浓度对脱色反应速度的影响;通过动力学模拟及反应过程中染料的UV-Vis扫描图分析,探讨了脱色反应机理。结果表明：Citrobacter sp. CK3对活性红KN-3B的脱色反应的适宜pH为7～9;脱色反应速度在温度为32℃时达到最大。染料初浓度从57 mg/L逐渐增大到458 mg/L时脱色率逐渐降低。脱色过程中染料的偶氮键发生断裂,脱色反应符合二级反应动力学。     

Effects of different methods of DNA extraction for activated sludge on the subsequent analysis of bacterial community profiles

The effect of different DNA extraction protocols on activated sludge DNA yield and bacterial community composition was evaluated by temperature gradient gel electrophoresis (TGGE). Nine different procedures to extract DNA were compared-sonication (30s), sonication (40s), sonication (50s), freezing-thawing, bead milling, sodium dodecyl sulfate (SDS)-lysozyme, SDS-proteinase K, SDS-lysozyme-proteinase, and a commercial extraction kit. It was found that the TGGE profiles and the DNA band numbers made significant differences via various extraction methods. The yield and purity of DNA extracted by sonication and other physical methods were not satisfactory, while the DNA purity extracted by SDS and other chemical-biological methods were better. Crude DNA extracts isolated by sonication and other physical methods passed the polymerase chain reaction, despite the absence of purification and acquired affluent DNA bands in TGGE. The affluence of bands in TGGE was not consistent with the yield and purification of DNA, but was correlative with extraction protocols. To analyze the activated sludge bacterial community by TGGE fingerprint, it is necessary to make a synthesis of the TGGE fingerprint profiles of chemical and physical DNA extraction methods to overcome the representative bias.