Water and sediment quality in Qinghai Lake,China: a revisit after half a century

Qinghai Lake, situated on the Qinghai–Tibet plateau, is the largest lake in China. In this study, the water and sediment quality were investigated in Qinghai Lake, three sublakes, and five major tributaries. Both Na⁺ and Cl^? were found to be the major ions present in Qinghai Lake and the three sublakes, while Ca²⁺ and HCO^3? dominated the tributaries. Compared with historical data from the 1960s, the concentrations of NH₄ ⁺, NO₃ ^?, and soluble reactive silica have increased considerably, likely caused by increased human activities in the area. Compared to the historical data, chemical oxygen demand has increased and lake water transparency has decreased, likely related to an increase in nutrient levels. Relatively high concentrations of total nitrogen (TN) and total phosphorus (TP) were observed in Qinghai Lake sediments, although P fraction types and low water concentrations of these two indicate low possibility of transfer into the water column. The ratios of C/N suggest that the organic matter in the sediments are primarily from autochthonous sources. TN and total organic carbon in the sediment cores increased slowly up the core while TP and total inorganic carbon have been fairly constant.     

超临界水氧化法处理高浓度有机发酵废水

对酒精废水和乙酰螺旋素废水进行了超临界氧化降解的研究,结果表明,超临界水氧化法是处理高浓度有面废水的一种有效方法,在实验的条件范围内,废水ＣＯＤ的去除率最高可达９９．２％。     

餐厨废弃物的环境昆虫处理途径及资源化利用探讨

餐厨废弃物的不当处理,不但直接影响城市容貌、污染地下水、食品安全及人们身体健康,同时造成巨大的资源浪费.餐厨废弃物的处理已经成为政府及社会广为关注的重大问题.介绍了餐厨废弃物处置管理的意义,分析了目前几种生物处理技术的现状,提出了利用环境昆虫进行餐厨废弃物资源化利用的有关建议.     

Xia Futou's public bathhouse--a sustainable urbanization experiment in a Chinese village

Xia Futou, a small Chinese village with a unique cultural landscape, consists of two unbalanced parts, an old village up the hill and a new one down the hill. In order to upgrade and preserve the unique cultural landscape of the older village and rebalance the dislocation of the two parts, a small public bathhouse project has been carried out according to sustainable architecture principles. Based on the current cultural landscape of the bathhouse and its surroundings, this approach is attempting to localize an informed, balance-seeking, design process in the village and in so doing develop a series of diverse possibilities and beneficial paths. The experiment of the public bathhouse's design and construction led to two key conceptual questions that need to be examined, the one is to research a village with a dynamic system conception instead of a static one; the other is to research a village with a self-organizing system conception1 instead of an organized one. Furthermore, we can give the sustainable path for the future that such naturally evolved Chinese villages evolve into sustainable towns and cities.     

铁改性竹炭去除水中的As(Ⅲ)和As(Ⅴ)

利用竹炭负载铁氧化物制备了复合吸附剂,并用粉末X射线衍射对负载的铁进行了表征。通过静态吸附实验,对比研究了改性竹炭对水溶液中As(Ⅲ)和As(Ⅴ)阴离子的吸附特性。结果表明,载铁竹炭对As(Ⅲ)和As(Ⅴ)的最佳吸附pH分别为8和2。改性竹炭对砷阴离子的吸附过程可符合准二级动力。Freundlich等温方程式能很好地描述As(Ⅲ)和As(Ⅴ)在改性竹炭上的吸附。在相同初始浓度和吸附剂投加量下,改性竹炭对As(Ⅴ)的吸附量大于As(Ⅲ)。     

冬季不同生境下菹草的水质净化效果研究

在室外通过人工构建静态模拟生态系统,研究冬季不同底质、水深、水质条件下,菹草对水体营养盐的吸收净化效果。结果表明,在不同水深或水质污染程度的相应组实验中,添加土壤改良剂的各组实验的TN、TP、NO3--N、高锰酸盐指数去除率均高于相应的未添加组,而NH4+-N去除情况相反;添加土壤改良剂有助于菹草对水体营养盐的综合去除,菹草在水深较深且营养盐负荷较高的水体中对营养盐的去除效果更好;水深35cm比水深25cm更适宜菹草的生长;菹草在实验设计的水质条件下能正常生长和对水质进行高效净化,适合在冬季运用于一般河道的水体修复。     

Activation of peroxymonosulfate by catalysts derived from water treatment plant sludge for the simultaneous removal of Disperse Blue 56 and phosphates

Environmental Science and Pollution Research - In this study, calcined water treatment plant sludge (C-WTPS) was used as a catalyst for peroxymonosulfate (PMS) activation to simultaneously remove...     

Structure relationship for catalytic dechlorination rate of dichlorobenzenes in water

Three isomers of dichlorobenzene (o-, m- and p-DCB) were dechlorinated by Pd/Fe catalyst in aqueous solutions through catalytic reduction. The dechlorination reaction took place on the surface site of the catalyst via a pseudo-first-order kinetics, and resulted in benzene as the final reduction product. The rate constants of the reductive dechlorination for the three dichlorobenzenes (DCBs) in the presence of Pd/Fe as a catalyst were measured experimentally. In all cases, the reaction rate constants were found to increase with the decrease in the Gibbs free energy of the formation of DCBs. The reaction rate constant for o-, m- and p-DCBs in the presence of 0.020% (w/w) Pd/Fe at 25 °C was determined to be 0.0213, 0.0223, and 0.0254 min⁻¹, respectively. While the activation energy of each dechlorination reaction was measured to be 102.5, 96.6 and 80.0 kJ mol⁻¹ for o-, m- and p-DCBs, respectively. The results demonstrated that p-DCBs were reduced more easily than o- or m-DCBs, and the order of the tendency of the dechlorination was p-DCB > m-DCB > o-DCB. The presented data show the catalytic reduction using Pd/Fe as a catalyst is a fast and easy approach for the dechlorination of DCBs.     

废铁屑处理难生物降解染料废水

研究了用废铁屑处理难生物降解的染料废水，考察了进pH值、曝气时间、固液比、铁屑粒度对废水处理效果的影响，并确定了适宜实验条件。实验证明，该法可以有效去除染料废水的色度和CODcr，在实验考察范围内，脱色率和CODcr去除率分别可达90％、61.7%。同时废水可生化性也得到了改善，BOD5／CODcr从19.6%上升到29.5%，提高了50％,有利于后续生化处理。该法以废治废，是一种很有实用价值的废水处理方法。