Mud-Dominated Storm Deposits From A Lower Carboniferous Ramp

The Lower Carboniferous Pen-y-Holt Limestone of South Wales comprises about 300m of interbedded wackestones and lime mudstones. The wackestones are interpreted as relatively distal ‘turbidite-like’ storm-generated deposits and the lime mudstones as background deposits. The storms had a periodicity of about one per 9000–18000 years. They were deposited in a deep-ramp carbonate environment at least 20–30km from the ancient shoreline and in about 100m water depth, and therefore probably below wave base. The ramp is estimated to have had an average slope angle of 0·5–1·0 degree. Unlike other previously described carbonate or siliciclastic storm deposits, the Pen-y-Holt Limestone storm deposits are totaly mud-supported and generally lack internal sedimentary structures, yet contain large bioclasts such as crinoid ossicles. The simultaneous deposition of lime mud and crinoid ossicles from a storm-generated turbidity current is hydrodynamically untenable. Thin-section evidence however, suggests that the lime mud may have originally been deposited as peloids which have since been largely destroyed during diagenesis. Peloids and crinoid ossicles, it is suggested, could have been transported by the same current.     

温郁金的石灰土栽培及其营养元素动态变化初步研究

为探索原产浙江温州地区的药用植物温郁金是否能在石灰土上生长,通过盆栽试验对比研究了温郁金在石灰土和红壤上生长及其生长过程中N、P、K、Ca、Mg、Fe 6种元素含量的动态变化。结果表明: 温郁金不但可以在石灰土上生长,而且其药用部位(莪术之一)的产量、莪术油的含量及莪术油中主要药用组分β -榄香稀等的含量都较大;石灰土上生长的温郁金在生长前期较快地表现出老叶明显发黄的缺肥症状,而红壤植株在追加N、P、K 3种大量元素后功能叶子呈现黄白色,且夹带有褐色斑点的缺肥症状;石灰土中Fe元素有效态含量比红壤低一个数量级,但在石灰土上种植的温郁金植株其Fe元素含量并不比红壤上的低。由此认为: ( 1)温郁金基本可以在石灰土上引种栽培;石灰土种植温郁金对施加化肥诱发的土壤元素缺乏具有较强的抵抗性; ( 2)温郁金元素的吸收受地质背景制约。      

Compressibility behaviour of lime-treated marine clay

The necessity to tap natural marine resources from the ocean beds represents a considerable challenge for the construction of offshore structures on weak marine deposits. The use of lime to improve the behaviour of soft clays is not new. The present investigation examines lime-induced changes in the compressibility of marine clay. The test results indicate a reduction of 1/2 to 1/3 in the compressibility of the soil system within 30 to 45 days of treatment. The formation of various cementation compounds due to soil–lime reactions improves the soil characteristics with time. The results encourage the application of lime column and lime injection techniques to improve the engineering behaviour of soft marine clayey deposits. However, one has to be cautious in applying the lime technique to marine clays that contain sodium sulfate.     

Operational Cost Comparison of Several Pre‐Treatment Techniques for OMW Treatment

Olive mill wastewaters (OMWs), which are known to have deep impacts on the receiving water bodies due to their high‐strength contents of organic materials and color, must be treated before discharge. For this reason; a number of research studies have been available in current literature related to the treatment of OMWs. However, no widely accepted treatment alternatives have been proposed yet. The common results of these studies suggest that OMWs must be pretreated prior to final purification processes. This study focuses on the comparison of alternative pre‐treatment processes in the aspect of chemical oxygen demand (COD) removal and costs of operation. Centrifuging, lime precipitation, acid cracking, and electrocoagulation processes were performed to compare removal efficiencies and operational costs. The COD removal efficiencies for centrifuging, lime precipitation, acid cracking, and electrocoagulation processes were determined to be 30.1, 24.1, 20.0, 53.7%, respectively, with operational costs being $0.30, $0.37, $1.42, and $11.60 per cubic meter of wastewater treated, respectively. The centrifuging process was concluded to be the most appropriate one according to the COD removal efficiency and cost of operation.     

水泥与生石灰处理吹填土对比试验研究

吹填土是由水力吹填形成的,颗粒很细,固结性能差,吹填以后要经过很长时间才能自然沉积固结,待表面形成硬壳后方可进行加固处理,因此,缩短沉积固结时间,使吹填土尽快地从泥浆状态转变为具有一定承载力的地基,是亟待解决的问题。在室内进行模拟加固方法的沉降柱试验,对吹填土加添固化剂以加速其沉积固结。固化剂主要选用水泥和生石灰,对两种添加方式的机理及固结效果进行详尽的分析和研究,初步找出加固效果产生差异的原因,从而揭示其固化机理,为吹填土地基的加固提供一种更加经济可行的方法。