Field demonstration and evaluation of the Passive Flux Meter on a CAH groundwater plume

This study comprises the first application of the Passive Flux Meter (PFM) for the measurement of chlorinated aliphatic hydrocarbon (CAH) mass fluxes and Darcy water fluxes in groundwater at a European field site. The PFM was originally developed and applied to measurements near source zones. The focus of the PFM is extended from near source to plume zones. For this purpose, 48 PFMs of 1.4 m length were constructed and installed in eight different monitoring wells in the source and plume zone of a CAH-contaminated field site located in France. The PFMs were retrieved, sampled, and analyzed after 3 to 11 weeks of exposure time, depending on the expected contaminant flux. PFM evaluation criteria include analytical, technical, and practical aspects as well as conditions and applicability. PFM flux data were compared with so-called traditional soil and groundwater concentration data obtained using active sampling methods. The PFMs deliver reasonable results for source as well as plume zones. The limiting factor in the PFM applicability is the exposure time together with the groundwater flux. Measured groundwater velocities at the field site range from 2 to 41 cm/day. Measured contaminant flux data raise up to 13 g/m²/day for perchloroethylene in the plume zone. Calculated PFM flux averaged concentration data and traditional concentration data were of similar magnitude for most wells. However, both datasets need to be compared with reservation because of the different sampling nature and time. Two important issues are the PFM tracer loss during installation/extraction and the deviation of the groundwater flow field when passing the monitoring well and PFM. The demonstration of the PFM at a CAH-contaminated field site in Europe confirmed the efficiency of the flux measurement technique for source as well as plume zones. The PFM can be applied without concerns in monitoring wells with European standards. The acquired flux data are of great value for the purpose of site characterization and mass discharge modeling, and can be used in combination with traditional soil and groundwater sampling methods.     

Experimental investigation on water absorption capacity of RHA-added cement concrete

Environmental Science and Pollution Research - In the recent past, partial replacement of cement by rice husk ash (RHA) in concrete is a prime focus of global researchers for sustainable...     

植物仿生与化学淋洗联合修复Cd污染土壤

采用植物仿生与化学淋洗联合修复技术对重金属Cd污染的工业场地进行修复,使用H2O、1%乳酸、5%乳酸和0.03 mol·L-1 EDTA溶液作为化学淋洗剂进行原位淋洗,通过改变土壤重金属存在形态以增加植物仿生修复技术的效率。同时研究了植物仿生修复装置大小及修复装置填料组成对植物仿生修复技术效率的影响。结果表明,经过3个月的修复,3块实验田Cd含量的降低率分别为81.97%、82.67%和67.67%,均达到国家土壤环境质量标准（GB15618-1995）规定的Cd三级标准。四种淋洗剂中,以EDTA的联合修复效率最高,为82.33%,其余联合修复效率依次为5%乳酸溶液（74.33%）、1%乳酸溶液（71.67%）、H2O（67.67%）。相关性分析表明,土壤Cd含量与乳酸呈负相关,差异显著;与EDTA呈负相关,差异极显著。植物仿生修复3个月后φ=5.0 cm的植物仿生修复装置的修复效率较φ=2.5 cm的高1.21倍;填料中增加5%赤泥对植物仿生修复效率无明显影响。     

不同填料对反应器充氧能力影响的比较研究

填料是生物接触氧化工和进气量的情况下DO的变化,分析填料对曝气池DO的转移速率有无影响.实验结果表明:对悬浮式填料而言,选择合适的曝气量,投加率在一定的范围内时,随着投加率的增加,曝气池充氧能力增强;对悬挂式填料而言,弹性立体填料的放射状细条结构对气泡起到较强的切割作用,提高了充氧效率.曝气池充氧能力受填料投加率的影响程度顺序为:弹性立体填料＞立体块式悬浮填料＞内置悬浮球形填料＞盾式填料.     

U.S. EPA SITE demonstration of AWD Technologies' AquaDetox/SVE system.

Under the Superfund Innovative Technology Evaluation (SITE) Program, a technology developed by AWD Technologies, Inc. was demonstrated in September 1990. This paper presents the major results of the SITE demonstration of AWD Technologies' AquaDetox/SVE treatment system designed for simultaneous on-site treatment of contaminated groundwater and soil-gas. The groundwater and soil at the demonstration site were contaminated with trichloroethylene (TCE) and tetrachloroethylene (PCE). The AWD technology was evaluated on the basis of the removal efficiencies of TCE and PCE from the contaminated groundwater and soil-gas. The conclusions drawn from these evaluations are: (1) the system achieved removal efficiencies as high as 99.99 percent for groundwater and 99.9 percent for soil-gas; (2) the effluent groundwater was in compliance with the regulatory discharge requirements of 5 micrograms/L each for TCE and PCE for all test runs; (3) the demonstrated 1,000 gpm system has an estimated capital cost of $4.3 million and annual operating and maintenance cost of approximately $820,000.     

Fluoride effects on the mulberry-silkworm system

Absorption and accumulation of fluoride (F) from ambient air by mulberry leaves, and its transfer and effects on silkworm development, were examined. When the concentration of F in air exceeded 1.5 microg dm(-2). day (-1), using lime filter papers as static monitors, the F content of mulbery leaves was more than 30 ppm, the threshold for injury to silkworm larvae. Fluoride-polluted mulberry leaves inhibited growth and development of silkworms. Leaves containing more than 80 ppm F severely inhibited cocoon production. Fluoride was absorbed from the atmosphere by the mulberry leaf and was transferred to the silkworm, soil, water, and back to the atmosphere, forming a cycle.     

高效代谢解偶联剂的筛选及对SBR系统综合运行效能的影响

活性污泥法是最常用的污水处理技术,但它同时会产生大量的剩余污泥,需要进行额外的处理和处置.活性污泥的解偶联代谢能有效地减少剩余污泥的产量.比较了5种代谢解偶联剂,即2,4-二硝基苯酚(DNP)、邻氨基苯酚(AP)、2,4,6-三氯苯酚(TCP)、3,3',4,5-四氯水杨酰苯胺(TCS)、丙二酸的污泥减量效果和对COD去除能力的影响.结果表明,当它们在各自的最佳质量浓度20、1 5、4、1.2、15 mg/L时,污泥的表观增长系数分别降低了62.39%、63.75%、59.40%、34.58%和53.75%,而COD去除率仅有轻微下降.重点研究了15 mg/L的丙二酸和4 mg/L的TCP对SBR系统运行效能和污泥沉降性能的影响.发现在长期运行过程中,两者都能有效降低系统的污泥产量,而对COD去除率的影响较低,但使用丙二酸6 d后极大地影响了污泥的沉降性能,而TCP对污泥的沉降性能影响很小.     

Assessing the sustainability and adaptive capacity of the gooseneck barnacle co-management system in Asturias,N. Spain

The gooseneck barnacle fishery in Asturias (N. Spain) has undergone three important changes: (1) the early implementation of a co-management system based on Territorial User Rights for Fishing, (2) a change in management measures (due to a decrease in landings), and (3) an economic crisis. This has allowed us to analyze the systems’ sustainability in time through examining five critical variables: landings, effort, catch per unit effort (CPUE), mean market prices, and annual revenue. Additionally, we used focus groups and questionnaires to determine the response of the system to these three changes. Co-management has succeeded in maintaining or increasing CPUE throughout all management areas and produced stable mean market prices. This was achieved through flexible management policies and adaptive strategies adopted by the fishers, such as increased selectivity and diversification. The analysis of this fishery provides important lessons regarding the need to understand the evolutionary dynamics of co-management and the importance of embracing adaptive capacity.

Electronic supplementary material

The online version of this article (doi:10.1007/s13280-015-0687-z) contains supplementary material, which is available to authorized users.     

大田条件下施加组配改良剂对蔬菜吸收重金属的影响

通过向湘南某矿区周边重金属污染的农田施加不同添加量(0、2、4和8 g/kg)的组配改良剂HS(海泡石+石灰石),分析农田土壤理化性质变化和土壤重金属及其交换态含量的影响、空心菜和辣椒可食部位和根部位重金属含量的影响。结果表明,施用2~8 g/kg组配改良剂HS能使2种蔬菜土壤pH值和CEC含量显著增加,使交换态重金属含量大幅降低,且不同程度地降低了空心菜和辣椒可食部位及根部位的重金属含量。与对照相比,空心菜和辣椒可食部位重金属Pb、Cd、Cu、Zn的降幅分别为:21.1%~47.5%、6.5%~31.0%、57.7%~80.0%、65.3%~92.0%和27.3%~74.5%、29.8%~62.0%、55.4%~76%、37.8%~77.1%;根部位的重金属含量也有明显降低。当添加量为8 g/kg时,2种蔬菜可食部位和根部位重金属含量降低幅度最大。由此可知,组配改良剂HS的施用对2种蔬菜吸收土壤重金属起到有效的抑制作用。     

Combined effects of carbon nanotubes and cadmium on the photosynthetic capacity and antioxidant response of wheat seedlings

Environmental Science and Pollution Research - A detailed study of nanomaterials has revealed their broad application prospects. However, the presence of carbon nanotubes (CNTs) in the environment...     

Effects of reduced return activated sludge flows and volume on anaerobic zone performance for a septic wastewater biological phosphorus removal system.

Enhanced biological phosphorous removal (EBPR) performance was found to be adequate with reduced return-activated sludge (RAS) flows (50% of available RAS) to the anaerobic tank and smaller-than-typical anaerobic zone volume (1.08 hours hydraulic retention time [HRT]). Three identical parallel biological nutrient removal pilot plants were fed with strong, highly fermented (160 mg/L volatile fatty acids [VFAs]), domestic and industrial wastewater from a full-scale wastewater treatment facility. The pilot plants were operated at 100, 50, 40, and 25% RAS (percent of available RAS) flows to the anaerobic tank, with the remaining RAS to the anoxic tank. In addition, varying anaerobic HRT (1.08 and 1.5 hours) and increased hydraulic loading (35% increase) were examined. The study was divided into four phases, and the effect of these process variations on EBPR were studied by having one different variable between two identical systems. The most significant conclusion was that returning part of the RAS to the anaerobic zone did not decrease EBPR performance; instead, it changed the location of phosphorous release and uptake. Bringing less RAS to the anaerobic and more to the anoxic tank decreased anaerobic phosphorus release and increased anoxic phosphorus release (or decreased anoxic phosphorus uptake). Equally important is that, with VFA-rich influent wastewater, excessive anaerobic volume was shown to hurt overall phosphorus removal, even when it resulted in increased anaerobic phosphorus release.     

Assessing the nature of the combined effects of copper and zinc on estuarine infaunal communities

Elevated levels of copper and zinc in sediment have been shown to adversely affect estuarine infauna. We investigated the additivity of the combined effects of copper and zinc on infaunal recolonisation through a manipulative field experiment in Orewa estuary, New Zealand, using defaunated sediment discs treated with these metals. The nature of their combined effects varied among infaunal taxa and the particular variables being examined. Additive effects were detected for species richness, for the mean log abundances of the polychaetes Prionospio sp. and Scoloplos cylindrifer and for the multivariate response of the community as a whole. Antagonistic effects were detected for the mean log abundances of total infauna and the polychaete Heteromastus sp. Characterising the potentially interactive nature of the combined effects of multiple heavy metals is essential in order to build predictive models of future environmental impacts of metal accumulation in estuarine sediments.     

Influence of detergent formulation on nutrient movement through sand columns simulating mound and conventional septic system drainfields

The effects of phosphate (P) and zeolite (Z) -built detergents on leaching of N and P through sand columns simulating septic system drainfields were examined in laboratory columns. To simulate mound septic system drainfields, paired sets of columns were dosed intermittently with septic tank effluent from households using P- or Z-built detergent. Two other paired sets of columns were flooded with P- or Z-effluent to simulate new conventional septic system drainfields; after clogging mats or “crusts” developed at infiltration surface, the subsurfaces of the columns were aerated to simulate mature (crusted) conventional septic system drainfields. NO₃ loading in leachate was 1.1 times higher and ortho-P loading was 4.3 times lower when columns were dosed with Z- than with P-effluent. Dosed columns removed P poorly; total phosphorus (TP) loading in leachate was 81 and 19 g m⁻² yr⁻¹ with P- and Z-effluent, respectively. In flooded columns 1.3, 2.0 and 1.8 times more NH₄, organic nitrogen (ON) and total nitrogen (TN) respectively, were leached with Z- than with P-effluent; NO₃ leaching was similar. Flooded columns removed P efficiently; TP leached through flooded systems was 2.5 and 1.4 g m⁻² yr⁻¹ with P- and Z effluent, respectively. Crusted columns fed Z-effluent leached 1.2, 2.6, 1.4 and 2.1 times more NH₄, NO₃, ON and TN, respectively, than those with P-effluent but 1.8 times less TP. Crusted columns removed P satisfactorily: 8.2 and 4.6 g m⁻² yr⁻¹ TP with P- and Z-effluent, respectively. The P-built detergent substantially improves the efficiency of N removal with satisfactory P removal in columns simulating conventional septic system drainfield. Simultaneous removal of N and P under flooded conditions might be explained by precipitation of struvite-type minerals. Dosed system drainfields were less efficient in removing N and P compared to flooded and crusted system drainfelds.     

EPA SITE demonstration of the BioTrol soil washing process.

A pilot-scale soil washing process, patented by BioTrol, Inc., was demonstrated on soil contaminated by wood treating waste, primarily pentachlorophenol (PCP) and creosote-derived polynuclear aromatic hydrocarbons (PAHs). Although soil washing was the main object of this demonstration, the treatment train that was evaluated included two other BioTrol technologies for treatment of waste streams from the soil washer. The three technologies were: The BioTrol Soil Washer (BSW)--a volume reduction process, which uses water to separate contaminated soil fractions from the bulk of the soil. The BioTrol Aqueous Treatment System (BATS)--a biological water treatment process. The Slurry Bioreactor (SBR)--a BioTrol biological slurry treatment process conducted in an EIMCO BIOLIFT reactor. The sandy soil at the site, consisting of less than 10 percent of fines, was well suited for treatment by soil washing. The soil washer was evaluated in two tests on soil samples containing 130 ppm and 680 ppm of PCP, respectively. The BSW successfully separated the feed soil (dry weight basis) into 83 percent of washed soil, 10 percent of woody residues, and 7 percent of fines. The washed soil retained about 10 percent of the feed soil contamination while 90 percent of the feed soil contamination was contained within the woody residues, fines, and process water. The soil washer achieved up to 89 percent removal of PCP and 88 percent of total PAHs, based on the difference between their levels in the as-is (wet) feed soil and the washed soil.(ABSTRACT TRUNCATED AT 250 WORDS)     

Field and laboratory investigations on the effects of road salt (NaCl) on stream macroinvertebrate communities

Field and laboratory experiments were conducted to examine the effects of road salt (NaCI) on stream macroinvertebrates. Field studies investigated leaf litter processing rates and functional feeding group composition at locations upstream and downstream from point source salt inputs in two Michigan, USA streams. Laboratory studies determined the effects of increasing NaCl concentrations on aquatic invertebrate drift, behavior, and survival. Field studies revealed that leaves were processed faster at upstream reference sites than at locations downstream from road salt point source inputs. However, it was sediment loading that resulted in partial or complete burial of leaf packs, that affected invertebrate activity and confounded normal leaf pack colonization. There were no significant differences that could be attributed to road salt between upstream and downstream locations in the diversity and composition of invertebrate functional feeding groups. Laboratory drift and acute exposure studies demonstrated that drift of Gammarus (Amphipoda) may be affected by NaCl at concentrations greater than 5000 mg/l for a 24-h period. This amphipod and two species of limnephilid caddisflies exhibited a dose response to salt treatments with 96-h LC50 values of 7700 and 3526 mg NaCl/l, respectively. Most other invertebrate species and individuals were unaffected by NaCl concentrations up to 10,000 mg/l for 24 and 96 h, respectively.     

Modelling the effects of water diversion and combined sewer overflow on urban inland river quality

In order to assist and optimize the operation of a clean water diversion project for the medium-sized inland rivers in Chaohu, China, an integrated hydrodynamic and water quality model was used in this study. Sixteen diversion scenarios and five sewage interception scenarios were defined to assess the improvement of water quality parameters including ammonia nitrogen (NH₃-N), total phosphorus (TP) and chemical oxygen demand (COD) under different diverted water flows, diverting times, diverting points, diverting routines and sewage interception proportions. An index of pollutant removal rate per unit diverted water flow (PRUWF) was proposed to evaluate the effect of the clean water diversion. Results show that operating conditions played important roles in water quality improvement of medium-sized inland rivers. The optimal clean water diversion was operated under the conditions of a flow rate of 5 m³/s for 48 h with an additional constructed bridge sluice. A global sensitivity analysis using the Latin Hypercube One-Factor-at-a-Time (LH-OAT) method was conducted to distinguish the contributions of various driving forces to inland river water restoration. Results show that sewage interception was more important than diverted water flow and diverting time with respect to water quality improvement, especially for COD.     

污泥干化焚烧联用系统最佳运行工况研究

污泥干化焚烧联用系统将污泥焚烧产生的能量用于污泥干化,可实现污泥处理的节能降耗。对于污泥干化焚烧联用系统的运行,进厂污泥负荷、初始含水率、热值、污泥干化目标含水率是最大的影响因素。为实现污泥干化焚烧联用系统的低能耗和安全稳定运行,结合国内某污泥干化焚烧处理工程,建立了污泥干化焚烧联用系统能量和物料平衡模型,在此基础上研究了变工况条件下污泥干化焚烧联用系统的运行模式,分析了运行负荷、污泥热值、进厂污泥含水率、入炉污泥含水率发生波动时,对污泥干化单元和污泥焚烧单元所产生的影响,并提出了对应的运行策略。     

Investigation of retardation effects on the titanium dioxide photodegradation system

The photocatalytic bleaching of dyes using TiO2 has appeared promising in laboratory studies, but little attention has been focused on whether other species such as might be found in wastewater have a deleterious effect on the photobleaching. This study describes the effects that result from the presence of ionic species, organic solvents and humic substances on the photobleaching of several dyes. The manner in which the photobleaching was affected by the presence of adventitious materials was carefully examined with an eye toward elucidating the mechanistic origin of the loss of the photochemical efficiency in the reaction. The overall retardation effects can be attributed to the combination of light attenuation, inhibition and competition effects.     

Novel semi-decentralised mobile system for the sanitization and dehydration of septic sludge: a pilot-scale evaluation in the Jordan Valley

Environmental Science and Pollution Research - The provision of effective sanitation strategies has a significant impact on public health. However, the treatment of septic sludge still presents...     

Genotoxic effects and molecular docking of 1,4-dioxane: combined protective effects of trans-resveratrol

Environmental Science and Pollution Research - In this study, the protective effects of trans-resveratrol (t-resv) against 1,4-dioxane-induced toxicity in meristematic cells were investigated. For...