Physicochemical and biological treatability studies of urban solid waste leachate

In this research, physical, chemical and biological treatability of Tehran solid waste leachate was studied. Results indicate that the amount of COD for the fresh raw leachate of Tehran is equal to 66,608 mg/l. The leachate is transferred to an equalization tank for storage and pH control process. After neutralization, leachate is introduced to an up flow and down flow anaerobic reactor. The effluent of anaerobic reactor is conducted to a sequencing batch reactor. Sequence batch reactor (SBR) effluent was pumped in to sand and activated carbon filters, after chemical coagulation and clarification. Results showed that anaerobic reactor with detention time of 3 days had a 35% COD removal and increasing the detention time to 4.5 days would improve the COD removal to 45%. Nutrient adjustment with phosphorus and nitrogen increased the initial 23% efficiency of sequence batch reactor to 44%. The effluent COD of SBR reactor was 21,309 mg/l. Recycling of aerobic reactor effluent with incoming feed to anaerobic reactor reduced the anaerobic reactor influent COD to 20,000 mg/l and this caused 53% and 57% COD removal in the anaerobic and aerobic effluent, respectively. The total systems COD performance increased to 80% and SBR effluent COD eventually reduced to 4,000 mg/l. Coagulation, flocculation and sedimentation processes were practiced to make the 4,000 mg/l effluent COD comply with environmental standards of Iran. The optimum coagulant found to be ferric chloride with the dosage of 50 mg/l at pH of 12, which reduced 10% of COD to an amount of 3,676 mg/l. The effluent was stored in a tank and then pumped in to pressure sand filter and afterwards to activated carbon filter. The COD removal was three and 90% for sand and activated carbon filters, respectively. The total process reduced the remaining COD to 36 mg/l, which is in compliance with environmental standards of Iran.     

Possible impact of shallow interfluve traps on groundwater remediation

Shallow stratigraphic traps exist in certain geologic environments, which might complicate groundwater remediation efforts. Too often, pump-and-treat remediation wells are installed in geometric patterns designed to maximize cleanup operations. If, however, shallow stratigraphic traps are present, certain contaminants may be locally trapped and thus missed during cleanup operations. Alternatively, if shallow stratigraphic traps are delineated prior to location of cleanup wells, fewer wells may be needed for remediation. For example, a single well located at the trap apex, coupled with a single injection well, might be sufficient if: (1) all contaminants were contained in the trap, and (2) the trap was not laterally extensive. Interfluve stratigraphic traps are formed when braided outwash sands are subsequently covered by backswamp or lacustrine clay deposits. Such traps are common near-surface features of the valley train deposits of the Lower Mississippi River Valley and have relief of a few tens of centimeters to perhaps in excess of 10 m. Interfluve traps are also expected to commonly occur in many glaciated regions. Due to channel migration during backswamp clay deposition, and differing thicknesses of clay cover, it is unlikely that all interfluve traps can be delineated by a single method. Therefore, several geological techniques that might be useful in delineating shallow interfluve traps are briefly discussed here, as well as potential complications in using the described methods.     

前陆盆地斜坡带勘探丛式平台优选评价——以厄瓜多尔奥连特盆地TW区块为例

针对南美前陆盆地斜坡带圈闭规模小、热带雨林地貌勘探投资大、丛式平台优选难的问题,以厄瓜多尔奥连特盆地TW区块为例,在圈闭地质风险评价后,进行平台控圈闭群经济性评价,最终实现丛式平台优选评价。评价方法流程包括：1）圈闭地质风险评估和圈闭资源量评价（传统六要素评价）;2）丛式平台经济评价,设计N个平台（每个平台控制圈闭不同）,对单一平台控制范围内的圈闭进行经济性评价,包括投资（钻井、平台建设、道路及管线建设、射孔费用、地表植被复原费等）和收益（原油出售）,剔除没有经济价值的圈闭后重新对单一圈闭的经济性进行评价,直至单一平台内所有圈闭均具有经济价值;3）丛式平台和圈闭优选：根据单一平台控制圈闭总经济价值大小,优选出最优的丛式平台,按照经济价值大小对最优平台控制圈闭进行优选获得圈闭排序;4）新一轮平台和圈闭优选,删除已选出的圈闭后重新进行步骤2）-3）,最终获得研究区的平台及圈闭优选排序。运用该方法提出TW区块平台建设和圈闭钻探建议,实施效果良好。     

Monsoonal changes inferred from the Middle to Late Holocene sediments off Landfall Island,North Andaman

In this paper, sediment texture, clay mineral composition, and δ ¹⁸O data on Globigerinoides ruber of a sediment core collected from a water depth of 250 m near Landfall Island, Bay of Bengal, is presented to understand paleoenvironmental shifts during the Mid–Late Holocene period. From the sediment core, five organic carbon-rich samples were radiocarbon dated and the reservoir-corrected ages range from 6,078 to 1,658 years BP. The marine sediment core is represented dominantly by clayey silt with incursions of coarser components that occur around 6,000, 5,400, and 3,400 years BP. The sedimentation of the coarser detritus is due to strengthened southwest monsoon (SWM) since 6,500 to 5,400 years BP. Clay minerals are represented by smectite, illite, kaolinite, and chlorite in varying amounts. High kaolinite content and K/C ratio indicate intense SWM and strong bedrock weathering from the hinterland (~6,500–5,400 years BP). Incidence of smectite (48.82 to 25.09 %) and chlorite/illite (C/I) ratio (0.56 to 0.28) indicate an overall weakened southwest monsoon since 6,000 to 2,000 years BP with a brief incursion of extremely reduced SWM around 4,400 to 4,200 years BP. This is corroborated with the oxygen isotope on G. ruber that reveals a significant shift in the isotopic values ~4,300 years BP (?3.39?‰), indicating weakening in SWM. Subsequently, fluctuations in the intensity of SWM are observed since 2,000 years to present.     

Comparison of biostimulation and bioaugmentation for remediation of soil contaminated with spent motor oil

Aerobic fixed bed bioreactors were used to study and compare biostimulation and bioaugmentation for remediation of soil contaminated with spent motor oil. Bioaugmentation using consortium of bacteria and biostimulation using inorganic fertilizer and potassium dihydrogen orthophosphate were investigated. The bioremediation indicators used were the oil and grease content removals, total heterotrophic bacteria counts and carbon dioxide respiration rates. Results showed that biodegradations were very effective with 50, 66 and 75 % oil and grease content removal efficiencies for control, bioaugmentation and biostimulation respectively after ten weeks. Carbon dioxide respiration followed similar pattern as the oil and grease content removals. Biostimulation option has the highest carbon dioxide generation (6 249 mg/kg) and the control with the least (4 276 mg/kg). Therefore, the biostimulation option can be used to develop a realistic treatment technology for soils contaminated with spent motor oil.     

Sampling characteristics and biases of enclosure traps for sampling fishes in estuaries

We evaluated the sampling characteristics of enclosure traps in estuaries in southern California, USA. Using enclosure traps that sampled 0.25, 0.5, and 1-m² footprints, we found that enclosure trap size significantly affected estimates of fish density and the precision of these estimates. The highest estimates were produced by the 0.5-m² trap and the lowest by the 0.25-m² trap. Precision of the density estimates improved with increasing trap size, while the proportion of zero values in the data sets decreased and estimates of species richness increased. The largest trap was difficult to use in the field and often did not function properly; thus we concluded that intermediate enclosure trap sizes offered the best compromise between statistical and logistical considerations. By examination of burrows in sediment cores taken in fished out enclosure traps, we found no evidence to support the widely held view that burrow-dwelling fishes evaded capture by hiding in burrows. We also used mark-recapture techniques to estimate recovery efficiency in 0.43-m² enclosure traps. Recovery efficiency averaged 91% and did not differ significantly among estuaries or sampling stations within estuaries. Based on extensive netting within enclosure traps, we determined that in areas with dense fish populations (>90 fish 0.43-m⁻²), netting could be ceased after the first sweep that captured no fish with only a trivial effect on the estimate of density. In more sparsely populated areas, netting had to continue until 2–3 sweeps had captured no fish in order to obtain estimates of density that were within 90% of the actual values present. Overall, we found enclosure traps to be effective tools for sampling small, abundant fishes in shallow estuaries in southern California, but we recommend that care be taken when choosing trap size and sampling (netting) effort within traps in order to optimize their sampling characteristics.     

Feasibility study of water purification using vertical porous concrete filter

Cheapest and simplest techniques of filtration systems are required for rural water treatment in developing countries. Using a filter made of blocks for the water treatment enables us to make porous concrete filter and use it vertically. It is expected that the required area would decrease by more than 70 % if porous concrete filters were used vertically. The operation and backwash mode would be simpler than using horizontal sand filters as filters made of blocks would be used instead. The feasibility study focused on finding adequate materials, compositions and methods of making a block with enough resistance to water pressure, sufficient porosity for water transformation and using inexpensive and available materials. A pilot study was performed to determine an appropriate thickness of filter. Testing the porous filter in another pilot study using the low overflow rate of river water showed biological growth in that media and an adequate efficiency of about 90–100 % was obtained for decreasing the coliform bacteria. The required backwash water was 2.9 % of total treated water.     

Amino acid composition of suspended particles,sediment-trap material,and benthic sediment in the Potomac Estuary

Sediment trap deployments in estuaries provide a method for estimating the amount of organic material transported to the sediments from the euphotic zone. The amino acid composition of suspended particles, benthic sediment, and sediment-trap material collected at 2.4 m, 5.8 m, and 7.9 m depths in the Potomac Estuary was determined in stratified summer waters, and in well-mixed oxygenated waters (DO) in late fall. The total vertical flow, or flux, of material into the top traps ranged from 3 g m^?2 d^?1 in August to 4.9 g m^?2 d^?1 in October. The carbon and nitrogen fluxes increased in the deepest traps relative to the surface traps during both sampling periods, along with that of the total material flux (up to 47.3 g m^?2 d^?1 in the deepest trap), although the actual weight percent of organic carbon and organic nitrogen decreased with depth. Amino acid concentrations ranged from 129 mg g^?1 in surface water particulate material to 22 mg g^?1 in particulate material in 9-m-deep waters and in the benthic sediment. Amino acid concentrations from 2.4-mg-depth sediment traps averaged 104±29 mg g^?1 in stratified waters and 164±81 mg g^?1 in well-mixed waters. The deep trap samples averaed, 77.3±4.8 mg g^?1 amino acids in summer waters and 37±16 mg g^?1 in oxygenated fall waters. Amino acids comprised 13% to 39% of the organic carbon and 12% to 89% of the orgnaic nitrogen in these samples. Analysis of the flux results suggest that resuspension combined with lateral advection from adjacent slopes can account for up to 27% of the material in the deep traps when the estuary was well-mixed and unstratified. When the estuary was stratified in late summer, the amino acid carbon produced by primary productivity in the euphotic zone decreased by 85% (86% for total organic carbon) at the pycnocline at 6 m depth, leaving up to 15% of the vertical organic flux available for benthic sediment deposition.     

Prediction of water quality from simple field parameters

Water quality parameters like temperature, pH, total dissolved solids (TDS), total suspended solids (TSS), dissolved oxygen (DO), oil and grease, etc., are calculated from the field while parameters like biological oxygen demand (BOD) and chemical oxygen demand (COD) are interpreted through the laboratory tests. On one hand parameters like temperature, pH, DO, etc., can be accurately measured with the exceeding simplicity, whereas on the other hand calculation of BOD and COD is not only cumbersome but also inaccurate many times. A number of previous researchers have tried to use different empirical methods to predict BOD and COD but these empirical methods have their limitations due to their less versatile application. In this paper, an attempt has been made to calculate BOD and COD from simple field parameters like temperature, pH, DO, TSS, etc., using Artificial Neural Network (ANN) method. Datasets have been obtained from analysis of mine water discharge of one of the mines in Jharia coalfield, Jharkhand, India. 73 data sets were used to establish ANN architecture out of which 58 datasets were used to train the network while 15 datasets for testing the network. The results show encouraging similarity between experimental and predicted values. The RMSE values obtained for the BOD and COD are 0.114 and 0.983 %, respectively.     

固定化生物技术在合成染料废水处理中的应用

在多级折流板反应器生物处理装置中,采用活性炭为载体人工固定化生物处理合成染料废水,出水水质稳定, 出水中的烷烃肽链变短;其对COD_Cr和BOD₅的去除率可达96.46%、99.77% ;对SO^2-₄和钙镁总量的去除效率超过80.37%、78.66%;折流板反应器的容积负荷率N_v可达2.8 kg COD/(d•m³)。活性炭经生物固定化后,不仅不会影响它的处理效果,还会延长活性炭的使用寿命;当冲击性有机负荷发生时,固定化生物活性炭能够承受并能很快恢复。     

Bioadsorption by sugarcane bagasse for the reduction in oil and grease content in aqueous effluent

Several techniques have been used to reduce the oil and grease content in aqueous streams; one excellent is bioadsorption. With a view to provide a sustainable method for the treatment of oily effluents, the aim of this study was to evaluate sugarcane bagasse as bioadsorbent to reduce the oil and grease content of aqueous effluents. Analysis of the material was performed, and the adsorption experiments were in a batch system, using a synthetic effluent. The results showed that the kinetic equilibrium occurred in 0.08 h of contact. The study of influence of pH of the aqueous phase and the temperature showed that the adsorption capacity was proportional to the pH value, but inversely proportional to the temperature. The adsorption isotherm was obtained at a temperature of 298.15 K using the Langmuir and Langmuir–Freundlich models, and the maximum adsorption capacity obtained was 6.65 kg of hydrocarbon per kg of bioadsorbent. It was verified that sugarcane bagasse represents an excellent material for application in the treatment of oily aqueous effluents, since it is associated with low cost and a high adsorption capacity. The variation in the adsorption capacity observed as a function of pH of the aqueous phase was not found to be significant. This is an important characteristic of the material in terms of its industrial application, verifying the possibility for its implementation in any treatment process, demonstrating the great potential of sugarcane bagasse for use as a sustainable alternative in the reduction in oil and grease in aqueous effluents.     

山西运城水井建设中无棕滤水井管的设计与应用

通过运城地区水井的开凿,表明无棕结构的滤水管具有拦砂、滤水、增大出水量、提高成井率和延长水井寿命等优点。无棕滤水管的设计应当考虑多种影响因素:如滤料的选择、滤水管的孔隙率、滤水管的井径和缠丝间距等。对无棕滤水管工艺施工的水井的观测,井龄已满20年、井深140米的水井,其单位涌水量仍达6.14吨/小时·米,比采用有棕滤水管工艺施工的水井水量增大了93%,而且水质符合要求。     

Assessment of heavy metal accumulation in macrophyte, agricultural soil, and crop plants adjacent to discharge zone of sponge iron factory

The present study deals with the characterization of effluent released from sponge iron industries and distribution of heavy metals in soil and macrophytes near to effluent discharge channel. Apart from this, accumulation of heavy metals in nearby soil and vegetation system irrigated with effluent-contaminated water is also the subject of this study. Physico-chemical analysis of effluent reveals that the concentration of total suspended solids (TSS), total hardness (TH), iron (Fe²⁺), and oil and grease are greater than the IS (1981) norms for discharge of water into inland water body. The soil along the sides of the effluent channel also shows higher concentration of heavy metals than the background soil. The enrichment of the heavy metals are in the order of Chromium (Cr) > Iron (Fe) > Manganese (Mn) > Zinc (Zn) > Copper (Cu) > Cadmium (Cd). Macrophytes growing along the sides of the effluent channel also show significant accumulation of heavy metals almost in the same order as accumulated in soil. Higher uptake of heavy metals by these varieties reveals that these species can be used for future phytoremediation. The effluent as well as contaminated water is extensively used for irrigation for growing vegetables like tomato (Lycopersicon esculatum) in the surrounding areas. Heavy metal accumulation in this agricultural soil are in the sequence of Cr > Fe > Mn > Zn > Cu > Cd. More or less similar type of accumulation pattern are also found in tomato plants except Fe and Zn exceeding Cr and Mn. Transfer Factor of heavy metals from soil to tomato plants (TF_S) shows average value of <1, suggesting less uptake of heavy metals from soil. Among the plant parts studied, fruit shows least accumulation. Although tomato plants show some phenotypic changes, the survival of tomato plants as well as least accumulation of metals in fruit reveals their tolerance to heavy metals. Therefore it may be suggested that this plant can be grown successfully in the heavy metal contaminated soil. Further research work on in situ toxicity test will be necessary in order to identify the most resistive variety on this particular type of contaminated site.     

深盆气藏地质特征与研究意义——以鄂尔多斯盆地为例

深盆气藏位于构造下倾部位或盆地中央，上部含水，是具有特殊成藏地质条件的非常规气藏，深盆气藏具以下特征；气在水在上的气水倒置，气藏流体压力低于静水压力，烃源岩与气藏紧密伴生，源岩生气量大供气充足，油气热演化程度高，储层具低孔隙度低渗透率，单井产量低但地质储量大等，本以我国鄂尔多斯盆地为例进一步阐明深盆气藏的特征，国外对深盆气藏研究极为重视，天然气的产量也占有很大比重，在我国研究程度较低，深盆气的深入研究对我国天然气的勘探开发有重要意义。     

Treatment of polluted river water by a new constructed wetland

A new constructed wetland was built to purify one polluted river in Taiwan, and this study was conducted to evaluate the treatment efficiency of the wetland. Due to the very limitation of available budget, several water quality items, which were stipulated by Taiwan’s Environmental Protection Administration for rivers, in the influent and effluent of wetland were analyzed and evaluated. These items included water temperature, pH, DO, BOD₅, TSS, and NH₄ ⁺-N. The results showed that the average removal rates of total (unfiltered) BOD₅, TSS and NH₄ ⁺-N were 36.9 %, 71.8 % and 47.1%, respectively. With the HRT more than 3.4 days, the wetland could treat the polluted river water effectively. Longer HRT in this wetland appeared no obvious improvement on the removal rate of TSS or NH₄ ⁺-N. However, BOD removal rate increased while the HRT (Hydraulic Retention Time) increased to about 5 days. In this wetland, the calculated mean first-order reaction rate constant (k_T) for BOD₅ was 0.15/day with a standard deviation of 0.13/day and for NH₄ ⁺-N was 0.24/ day with a standard deviation of 0.18/day. It is also concluded that there is a linear proportional relationship between BOD concentrations in the effluent of wetland and its influent mass loading rates, with the coefficient of determination (R²) of 0.6511. Similar result was seen for NH₄ ⁺-N as well, with the coefficient of determination (R²) of 0.5965. TSS removal rate was found to be linearly proportional to its influent mass loading rate, with the coefficient of determination (R²) of 0.4875.     

Removal of contaminants from landfill leachates by filtration through glauconitic greensands

Passing landfill leachate through glauconitic greensand filters reduces the heavy metal cation content, lessens the unpleasant odor, and diminishes the murkiness of the leachate. The capability of the greensand to trap metal cations is increased by prolonging the contact time between the leachate and the greensand. Flushing the charged greensand filter with water does not cause significant release of cations back into solution, suggesting that polluted greensand might be disposed of at landfill sites without endangering the quality of either ground or surface water.     

移动平台全张量重力梯度数据的噪声抑制

全张量重力梯度仪器测量数据中包含了大量的白噪声和有色噪声。传统的数字滤波器只能滤除某一频段外的噪声,对于混叠在重力梯度有用信号频段范围内的有色噪声不能很好的对其进行分离。为了同时滤除白噪声和有色噪声,笔者利用卡尔曼滤波器采用增广矩阵法将全张量重力梯度数据中的有色噪声进行估计,在抑制白噪声的同时将有用信号和有色噪声分离,并利用数字滤波器与卡尔曼滤波器的优点,将其结合生了更好的滤波效果,得到了更高质量的梯度信号。通过模型试验验证了本方法对噪声的滤波能力,并满足高精度重力梯度数据处理要求。     

A method for the measurement of bedload sediment transport and passive faunal transport on intertidal sandflats

A simple and inexpensive sampler to measure bedload sediment transport in shallow subtidal or intertidal areas is described. The cylindrical sub-sediment trap with an aspect ratio of 20 (height: diameter) is an improvement over conventional bedload samplers which are difficult to use in shallow areas or fail to collect the biological material associated with bedload. Traps deployed on a low-energy intertidal sandflat for six months provided daily estimates of bedload transport (quartz grains: 0.001–40 kg m^?1 d^?1), passive infaunal transport (e.g., the bivalveMya arenaria, max: 800 ind m^?1 d^?1), and organic detrital flux (e.g., macrophyte fragments, max: 400 g dry wt m^?1 d^?1). Bedload rates estimated with traps were compared to predictions from a numerical bedload model to evaluate the trap’s collection and retention efficiency. A significant linear regression between observed (trap) and predicted (model) rates (r²=0.65, p<0.001, n=97) indicated that the traps were useful for the measurement of high- and low-frequency variability in bedload transport. Potential applications of the traps in benthic oceanography include recruitment and recolonization studies.     

相-势-源复合控油气成藏机制物理模拟实验研究*

含油气盆地的地质相、流体势、烃源灶是影响圈闭含油气性的决定性因素, 三者缺一不可。在各要素满足控藏临界条件下, 优相-低势-近源复合指数(FPSI) 越高, 圈闭含油气性越好。基于相-势-源复合控油气成藏机制开展物理模拟实验研究, 结果表明:“源”控制着油气成藏的物质来源, “相”控制着油气成藏的孔隙空间、“势”控制着油气成藏的运移动力, 当三者联合作用时能够形成油气藏。实验结果还表明, 圈闭外部(盖层)岩相和圈闭内部(储集层)岩相粒径差别越大, 越有利于油气在毛细管力作用下从细粒低孔渗的围岩之中进入到粗粒高孔渗的储集层之内聚集成藏, 临界条件是：圈闭外部围岩颗粒粒径较圈闭内部储集层颗粒粒径小2倍以上, 或外部毛细管力较之内部大2倍以上, 也即外部界面势能较内部高2倍以上;圈闭外部烃源岩含油气饱和度越高, 越有利油气进入圈闭内部储集层中聚集成藏, 临界条件是外部源岩的含油气饱和度达到和超过5％。     

Lead removal from wastewater using faujasite tuff

The Jordanian chabazite-phillipsite tuff and faujasite-phillipsite tuff have suitable mineralogical and technical properties that enable them to be used for ion-exchange processes. These include suitable grain size and total cation exchange capacity, acceptable zeolite content, good attrition resistance and high packed-bed density. The chabazite-phillipsite tuff (ZE1 and ZE2) has an excellent efficiency to remove Pb and an acceptable efficiency to remove Fe, Cu, Zn and Ni from effluent wastewater of a battery factory and other industries. The faujasite-phillipsite tuff (ZE3) is 6.97 times more efficient than the ZE1 and ZE2. A bed of ZE3 (1,000 kg) loaded in a 1.17-m³ column is capable of cleaning about 2,456 m³ of the effluent from the factory at a cost of US $200/ton. The wastewater is contaminated with 20 ppm Pb in the presence of competing ions including Ca (210 ppm), Na (1,950 ppm) and Fe (169 ppm). This quantity of wastewater is equivalent to 120 working days of effluent discharge from the factory at a flow rate of 20 m³/day.