Chloride and Organic Chlorine in Soil

Chloride is ubiquitous in soil, but the past years of research have revealed that organic matter also contains chlorine, in amounts similar to that of phosphorus. Hence, one of the major constituents of soil organic matter has previously been overlooked, and still very little is known about the turnover of organic chlorine in soil. In spite of the obvious connection between chloride and organic chlorine, organic chlorine rarely is considered when the biogeochemical cycling of chloride is in focus, and chloride rarely is taken into account when the occurrence and formation of natural organic chlorine compounds are in focus. The aim of the paper is to review ten years of research concerning the biogeochemical cycling of organic chlorine in soil, and to tie the biogeochemical cycling of organic chlorine to that of chloride.     

Migration of total chromium and chloride anion in the Rocha River used for estimating degradation of agricultural soil quality at the Thiu Rancho zone

The Rocha River is a receptor to receive wastewater from household, hospital and industry, from where contaminants are transported in the river, affecting biodiversity and the ecosystem of the area. In this paper we estimated the maximum transport of total chromium and chloride anion by applying the analytical model of Ogata & Banks (1961), and the results obtained are grouped into three zones: Contaminated, transition, and uncontaminated. The analytical model was applied with 13 samples collected from the river piezometers installed near Rocha, where they are arranged in two lines, i.e. RH-1 to RH-6 as the first line and RH-9 to RH-12 as the second line. The total chromium concentrations range from 0.16 mg/L (RH-1) and 0.11 mg/L (RH-9) at the closest points to Rocha River, to 0.13 mg/L (RH-7) and 0.03 mg/L (RH-12) at the most remote points to the river. The advance of the pollutants does not exceed 50 meters with respect to the axis of the Rocha River.     

Spatial and temporal variation of groundwater recharge in shallow aquifer in the Thepkasattri of Phuket,Thailand

Whether groundwater resources can be sustainably utilized is largely determined and characterized by hydrogeological parameters.Estimating the groundwater recharge is one of the essential parameters for managing water resources and protecting water resources from contamination.This study researched the spatial and temporal variation of groundwater recharge in the Thepkasattri sub-district through integrating chloride mass balance(CMB)and water table fluctuation(WTF)methods.The chloride content of representative rainfall and groundwater samples was analyzed.Besides,WTF method was adopted from groundwater level data from 2012 to 2015.According to the CMB method,the mean recharge was estimated to be 1172 mm per year,accounting for 47%of the annual rainfall.Moreover,the estimated recharge from the WTF method took 26%of annual rainfall in 2015.The recharge was underestimated according to the WTF method,because of the uncertainty in specific yield estimates and the number of representative wells in the study area.Moreover,the correlation between rainfall and water table fluctuation data indicated the positive linear relationship between two parameters.The spatial recharge prediction indicated that recharge was higher(1200-1400 mm/yr)in the eastern and western catchment,while that in the central floodplains was between 800 mm/yr and 1100 mm/yr.In addition,low recharge value between 450 mm/yr and 800 mm/yr was observed in the south-west part of Thepkasattri.The spatial variation of recharge partly reflects the influences of land use and land cover of the study area.     

褐牙鲆鳃氯细胞的超微结构研究

利用透射电镜技术，研究了褐牙鲆(Paralichthys olrvaceus)鳃氯细胞的超微结构特征。研究表明，褐牙鲆鳃氯细胞主要分布于鳃小叶基部，具有微细小管系统和分泌腔。有丰富的线粒体，细胞核基位。根据氯细胞结构的不同，将其分为4种类型：I型氯细胞、Ⅱ型氯细胞、Ⅲ型氯细胞和Ⅳ型氯细胞。I型氯细胞胞体较大，细胞基质密度较低。微细小管系统发达呈细管状；Ⅱ型氯细胞外形不规则。胞体较大，细胞基质密度较高，微细小管系统主要呈粗网状；Ⅲ型氯细胞外形不规则，细胞基质具有很高的电子密度，微细小管系统不发达，胞内存在大量线粒体，分泌腔小；Ⅳ型氯细胞为扁平状，细胞体积较小，具有较大的分泌腔，但微细小管系统不发达。褐牙鲆鳃氯细胞系统是主要的渗透压调节系统。     

Leaching of an oxide gold ore with chloride/hypochlorite solutions

An oxide gold ore was subjected to chloride/hypochlorite leaching at room temperature. The effects of three factors, including Ca(OCl)₂ vs. NaOCl, OCl⁻ concentration, and HCl concentration on gold leaching performance were investigated. Due to formation of CaOCl⁺ complex in solution and hence less reactivity, calcium hypochlorite produces a sluggish gold leaching kinetics, taking twice the time (46 h) to achieve maximum gold recovery of 58% compared to sodium hypochlorite. 10 g/L of total initial hypochlorite species in solution produces reasonable gold recoveries. The amount of added HCl and hence the initial pH was found to have a major effect on gold leaching kinetics and maximum gold recovery. A high level of 9 g/L of added HCl causes HClO to be very reactive, producing very fast kinetics, reaching 67% gold extraction in 4 h. It also causes a faster consumption of hypochlorous acid, through catalytic decomposition (by NiO and CuO) and disproportionation. Hypochlorous acid reactions with sulfide and ferrous content of ore proceed very slowly in the pH range of 4–11. Gold–chloro complexes are strongly adsorbed on quartz component of ore. To minimize this undesirable adsorption of gold–chloro species, the aging time must be limited to a few hours only.     

天山南坡科契卡尔巴西冰川物质平衡初步研究

基于2003—2005年考察期间观测的气温与降水资料,运用度日物质平衡模型模拟了天山南坡科契卡尔巴西冰川近期的物质平衡变化状况.结果表明:度日物质平衡模型模拟的冰川物质平衡值与实测值的变化趋势基本一致,模型模拟结果较为理想;2003/2004年度和2004/2005年度两个物质平衡年的平均物质平衡值分别为-494和-384 mm,平衡线高度(ELA)比20世纪70年升高了300 m左右.由此可见,在由暖干向暖湿转型的气候背景下,尽管降水增加显著,但强烈的升温导致科契卡尔巴西冰川处于强烈的物质亏损状态.     

Size of anal papillae in chironomids: Does it indicate their salinity stress?

Salinity of inland waters is affected by a range of human activities and is regarded as a major environmental contaminant in many parts of the world. Changes in salinity are well known to be associated with changes in macroinvertebrate communities of flowing waters. However, as many environmental factors co-vary with salinity, it is not known whether, and if so how, salinity causes communities to change. Being able to measure the osmoregulatory stress that individual stream macroinvertebrates are experiencing would be useful to understand if and how salinity affects their populations and thus communities. Additionally, inferring salinity stress in individual invertebrates could provide a valuable biomonitoring tool to detect the initial effects of salinity before major ecological changes have occurred. Osmoregulation in larval Chironomidae (Diptera) takes place in the anal papillae and their size is believed to be associated with osmoregulatory stress. In two laboratory experiments and a field survey in southern Victoria, Australia, we determine if the size of the anal papillae of larva chironomids is a useful biomarker of salinity stress. Experiments with Chironomus oppositus showed that the surface area of the anal papillae was similar in larva hatched across 5 egg masses collected from 3 sites but were affected by salinity treatments. Furthermore, the (transformed) ratio of this surface area to the body length of the larva was independent of the size of C. oppositus. However, for Chironomus cloacalis, this surface area differed between larva hatched from egg masses collected from the same site. The expected trend in surface area of the anal papillae relative to the size of larva (Chironomu alternans, C. cloacalis, Dicrotendipes sp., Criptochironomus sp. and Tanypodinae) was not duplicated in the field survey. It would appear that unknown factors, other than salinity, are affecting the size of the anal papillae of chironomids in southern Victoria.     

氯氧镁胶凝材料中总氯离子的测定：（I）预处理方法

氯氧镁胶凝材料的总Cl-含量是衡量产品吸潮、返卤和泛霜性能的关键指标之一。讨论了样品粉碎方式及硝酸酸溶浸取条件对样品中总Cl-测定的影响,并用优化后的预处理方法和台湾标准CNS14164方法对样品中总Cl-含量进行了分析。结果表明,手工研磨样品比机械粉碎样品中的总Cl-测定值偏高0.37%,相对偏差为3.91%;硝酸浓度对总Cl-的浸取有一定影响。经优化后的预处理方法为,取1 g用机械粉碎至88μm的粉末样品,用40 mL体积比为15/85的稀硝酸浸取20 min,再过滤洗涤得到待分析液。优化预处理方法后,测定Cl-的相对误差在0.44%以内,且有利于后续的滴定分析操作,精密度和准确度均优于CNS14164方法。     

Statistical Assessment of Unidirectional Propagation of a Leachate Contamination Plume

The leachate produced by the Municipal Solid Waste Landfill of São Pedro da Aldeia (State of Rio de Janeiro, Brazil) flows almost entirely in one direction guided by a natural ditch in the bottom of a gentle valley. This landfill has been in operation with no concern to environmental protection, such as containment systems or leachate drainage and treatment. This inadequate operation causes severe damage to flora, wildlife and local farmers, due to continuous propagation of contaminants in the groundwater. Field and laboratory measurements of ionic concentrations of several contaminants found in the groundwater adjacent the landfill are presented and interpreted in this paper. Several farms are located adjacent to the landfill, comprising about 1,000 inhabitants that use the ground water for personal use and land farming activities. The main purpose of this paper is to assess the environmental hazard to the surrounding properties as the landfill is still in operation. This is accomplished by estimating the maximum distance travelled by the leachate plume based on the statistical interpretation of the measured ionic concentration of several contaminants found commonly in landfills. The main recommendation coming from the statistical assessment is that safe groundwater consumption should be limited to a minimum distance of 400 m from the contamination source, provided that the quality of ground water is continuously monitored while the MSW landfill is still in operation.     

N—P—K复肥四元体系KCl—KH_2PO_4—CO（NH_2）_2—H_2O在

基于Ｎ—Ｐ—Ｋ三元复肥的物理化学基础．首次测定了四元体系ＫＣｌ—ＫＨ２ＰＯ４—ＣＯ（ＮＨ２）２在２９８．２Ｋ时的溶度及饱和溶液的折光率，绘制了体系的溶度图和折光率──组成图。该体系的溶度图属低共饱型，平衡固相为组份化合物，低共饱点组成为：１００ｇ饱和溶液中．ＫＣｌ１３．３１ｇ，ＫＨ２ＰＯ４３．３３ｇ，ＣＯ（ＮＨ２）２４７．２６ｇ，Ｈ２Ｏ３６．１０／１０ｇ。