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Sanitary Landfill (SLF) is designed on the principle of waste control and is characterized by the presence of a liner and a leachate collection system to prevent groundwater contamination and a capping system to prevent air contamination. This paper aims to design a SLF for an enduring and sustainable Solid Waste Management (SWM) system in Jeetpur Simara Sub-Metropolitan City (JSSMC), assisting researchers and designers working in the field of waste management with an easy methodology of SLF design and encouraging municipalities for SLF practice. An area type SLF of dimension 80 m x 80 m with a mineral linear system and a capping system can accommodate Municipal Solid Waste (MSW) of this city for 15 years in an environmentally sound modus producing an achievable amount of 3,434 x 106 m³ of Landfill Gas (LFG) over the lifetime of the SLF. The total heat content value of this achievable LFG over the lifetime of the landfill is about 6.40 x 1013 KJ. [ABSTRACT FROM AUTHOR]

Objectives. To investigate race and poverty in areas where oil and gas wastewater disposal wells, which are used to permanently inject wastewater from hydraulic fracturing (fracking) operations, are permitted. Methods. With location data of oil and gas disposal wells permitted between 2007 and 2014 in the Eagle Ford area, a region of intensive fracking in southern Texas, we analyzed the racial composition of residents living less than 5 kilometers from a disposal well and those farther away, adjusting for rurality and poverty, using a Poisson regression. Results. The proportion of people of color living less than 5 kilometers from a disposal well was 1.3 times higher than was the proportion of non-Hispanic Whites. Adjusting for rurality, disposal wells were 2.04 times (95% confidence interval = 2.02,2.06) as common in areas with 80% people of color or more than in majority White areas. Disposal wells are also disproportionately sited in high-poverty areas. Conclusions. Wastewater disposal wells in southern Texas are disproportionately permitted in areas with higher proportions of people of color and residents living in poverty, a pattern known as "environmental injustice." [ABSTRACT FROM AUTHOR]

The article offers science news briefs. Managing fish stocks and fisheries have been found to reduce bycatches in commercial fishing, referencing an article by Burgess et al. The role that wastewater injection depth into the ground plays in inducing earthquakes, referencing an article by Hincks et al., is mentioned. Infants' visual behavior and gaze have been found to be related to cognition, referencing an article by Cesana-Arlotti et al.

Unconventional oil and gas production provides a rapidly growing energy source; however, high-production states in the United States, such as Oklahoma, face sharply rising numbers of earthquakes. Subsurface pressure data required to unequivocally link earthquakes to wastewater injection are rarely accessible. Here we use seismicity and hydrogeological models to show that fluid migration from high-rate disposal wells in Oklahoma is potentially responsible for the largest swarm. Earthquake hypocenters occur within disposal formations and upper basement, between 2- and 5-kilometer depth. The modeled fluid pressure perturbation propagates throughout the same depth range and tracks earthquakes to distances of 35 kilometers, with a triggering threshold of ~0.07 megapascals. Although thousands of disposal wells operate aseismically, four of the highest-rate wells are capable of inducing 20% of 2008 to 2013 central U.S. seismicity. [ABSTRACT FROM AUTHOR]

The life span of subsurface flow treatment wetlands is determined by the clogging of the substrate. Thus, the influent should undergo primary treatment to reduce loadings of suspended solids and dissolved organic matter. An-organic based substrate should be less prone to clogging because of its remarkably higher porosity and plasticity. Mulch obtained from branches of the Canarian palm tree (Phoenix canariensis) has been tested as substrate for mixed flow, intermittently fed treatment wetland mesocosms processing high strength urban wastewater. The effect of the presence of plants (Phragmites and Cyperus), influent pressure and hydraulic loading rate was studied. The best removals (SS: 89%, COD: 77%, turbidity: 82%) have been obtained with planted reactors treating highly concentrated influents at the lower hydraulic loading rates tested. The palm tree mulch units achieved similar removals of SS, COD and turbidity to one having gravel as substrate and planted with common reed. Mulch obtained from stems of giant reed (Arundo donax) provided similar removals of SS and turbidity but that of COD was lower. The combination of organic-based TWs with gravel-based ones provided high removals (SS: 95%, COD: 78%, turbidity: 95%) while the risk of clogging was strongly reduced. [Copyright &y& Elsevier]

The estrogens estrone (El), 17β-estradiol (E2), and 17α-ethynylestradiol (EE2) cause potent endocrine disruptive effects on aquatic wildlife. Currently, four sources of released estrogens exist in Shanghai: treated effluent from municipal wastewater treatment plants (WTPs); wastewater discharge from livestock farms; untreated or simply digested sewage from rural households; and runoff from farmland with livestock manure (LM) applied and irrigated with livestock wastewater (LW). A modified estimation method for estrogen release, in consideration of the difference in estrogen excretion rates between Caucasian and Oriental people and estrogen reduction in livestock wastes, was presented in the study. Based on the estimation method, we estimated the amount of estrogen release from humans and livestock and analyzed the spatially explicit distribution of estrogen loads. By comparing the four estrogen sources, the amount of estrogens released to water environments from livestock (56.8 g d-1), in terms of E2 equivalents (EEQ), was nearly twofold higher than the EEQ from humans (35.2 g d-1), which accounted for 61.0% of the total EEQ in Shanghai. Regarding the livestock EEQ, land-applied and irrigated EEQ via surface runoff to water environments (0.11 g d-1) was obviously low compared with the EEQ of LW directly released into adjacent waterways (56.7 g d-1). Therefore, the LW was the major contributor to estrogenic risk to the water environment in Shanghai. The spatial distribution of estrogen loads indicated that the highest EEQloads were in the southern region of Pudong New Area and the eastern and central regions of Fengxian District. [ABSTRACT FROM AUTHOR]

Irrigation of dairy shed effluent (DSE) onto land is an integral part of New Zealand's farming practice. The use of inappropriate soils can result in contamination of ground waters with microbes and nutrients. A gap in our knowledge is the ability of stony soils to safely treat DSE. Replicates of four stony soils were collected from the Canterbury region of New Zealand as intact soil lysimeters 460 mm in diameter and up to 750 mm deep. The soils had either stones to the surface or 300 to 600 mm fines over stones. To determine breakthrough characteristics, a pulse of DSE (25 mm depth) spiked with bromide (2000 mg L-1) was applied to the soil cores followed by continuous artificial rainfall, for one pore volume, at 5 mm h1. Leachate aliquots were analyzed for Escherichia coli, bromide, and NH4+-N. The lysimeters were then subjected to hoof pugging using a mechanical hoof, and the E. coli leaching characteristics of the soil were determined again. Escherichia coli breakthrough curves revealed that the potential for E. coli to leach through the soils was high for Selwyn very stony soil and low for other soils analyzed. After pugging, leaching of E. coli increased in Mackenzie soil with stones to the surface. For most other soil cores, E. coli concentrations in soil leachates were low. In soils where stones are close to the surface, especially where the soil matrix is sandy, we anticipate that shallow groundwater is vulnerable to microbial contamination under some land management practices. [ABSTRACT FROM AUTHOR]

Disposal of untreated olive mill waste waters (OMW) is a serious environmental problem in many Mediterranean countries. The aim of this work was to assess whether changes in soil properties have occurred due to direct disposal of raw OMW on soil and in evaporation ponds, and to investigate the potential fate and transport of pollutants after olive oil production had ceased. The results clearly showed that uncontrolled OMW disposal is a significant source of pollution to surface soil and waters. Disposal of OMW on soil greatly increased electrical conductivity (EC), available phosphorous (P), exchangeable potassium (K) and magnesium (Mg), organic matter, polyphenols, total and inorganic nitrogen (N), and available micronutrients mainly in surface soil layers. The presence of a high content of clay and carbonates in soil act as barriers and prevent downward transport of pollutants. Residual levels of total carbon (C), polyphenols, total and inorganic N, exchangeable K+, available P, iron (Fe), and copper (Cu) were also elevated even 8 years after mill closure. The long term disposal of OMW highlights the need to establish soil quality standards for soil parameters in order to identify soils affected by the disposal of OMW. [ABSTRACT FROM AUTHOR]

The present paper focuses on a largely unexplored field of landfill-site valorization in combination with the construction and operation of a centralized olive mill wastewater (OMW) treatment facility. The latter consists of a wastewater storage lagoon, a compact anaerobic digester operated all year round and a landfill-based final disposal system. Key elements for process design, such as wastewater pre-treatment, application method and rate, and the potential effects on leachate quantity and quality, are discussed based on a comprehensive literature review. Furthermore, a case-study for eight (8) olive mill enterprises generating 8700 m3 of wastewater per year, was conceptually designed in order to calculate the capital and operational costs of the facility (transportation, storage, treatment, final disposal). The proposed facility was found to be economically self-sufficient, as long as the transportation costs of the OMW were maintained at ≤4.0 €/m3. Despite that EU Landfill Directive prohibits wastewater disposal to landfills, controlled application, based on appropriately designed pre-treatment system and specific loading rates, may provide improved landfill stabilization and a sustainable (environmentally and economically) solution for effluents generated by numerous small- and medium-size olive mill enterprises dispersed in the Mediterranean region. [Copyright &y& Elsevier]

The attenuation of Escherichia coli and total coliform from secondary treated wastewater effluent under two 'at-grade' effluent distribution systems was evaluated in a sandy silt vadose zone in a cold climate. The two at-grade distribution lines had different designs and hydraulic loading rates. Effluent transport was examined using chloride as a tracer. Coliform fate was evaluated relative to the chloride using a combination of in situ pore water sampling and destructive soil sampling, combined with the observation of a dye tracer along excavation sidewalls. Although bacteria attenuation in the subsoil appeared to decrease during colder, winter temperatures (likely due to decreased viability and decreased predation), the subsoil provided about a four log reduction in E. coli over 90 cm of vertical transport. Horizontal transport of bacteria (up to 1.5 m from the line) was likely aided by flow on top of a microbial biomat observed at the soil surface. Both the subsurface dye patterns and the E. coli sampling suggested less preferential flow occurred below the lower loading rate design. At-grade distribution of secondary treated wastewater appears to be a viable alternative to conventional distribution fields at sites with similar climate and soils. [ABSTRACT FROM AUTHOR]

Introduction: Composting may enhance bioremediation of PAH-contaminated soils by providing organic substrates that stimulate the growth of potential microbial degraders. However, the influence of added organic matter (OM) together with the microbial activities on the dissipation of PAHs has not yet been fully assessed. Materials and methods: An in-vessel composting-bioremediation experiment of a contaminated soil amended with fresh wastes was carried out. Four different experimental conditions were tested in triplicate during 60 days using laboratory-scale reactors: treatment S (100% soil), W (100% wastes), SW (soil/waste mixture), and SWB (soil/waste mixture with inoculation of degrading microorganisms). Results and discussion: A dry mass loss of 35 ± 5% was observed in treatments with organic wastes during composting in all the treatments except treatment S. The dissipation of the 16 USEPA-listed PAHs was largely enhanced from no significant change to 50.5 ± 14.8% (for SW)/63.7 ± 10.0% (for SWB). More obvious dissipation was observed when fresh wastes were added at the beginning of composting to the contaminated soil, without significant difference between the inoculated and non-inoculated treatments. Phospholipid fatty acid (PLFA) profiling showed that fungi and G-bacteria dominated at the beginning of experiment and were probably involved in PAH dissipation. Subsequently, greater relative abundances of G + bacteria were observed as PAH dissipation slowed down. Conclusions: The results suggest that improving the composting process with optimal organic compositions may be a feasible remediation strategy in PAH-contaminated soils through stimulation of active microbial populations. [ABSTRACT FROM AUTHOR]

The management of dewatered wastewater sludge is a major issue worldwide. Sludge disposal to landfills is not sustainable and thus alternative treatment techniques are being sought. The objective of this work was to determine optimal mixing ratios of dewatered sludge with other organic amendments in order to maximize the degradability of the mixtures during composting. This objective was achieved using mixture experimental design principles. An additional objective was to study the impact of the initial C/N ratio and moisture contents on the co-composting process of dewatered sludge. The composting process was monitored through measurements of O2 uptake rates, CO2 evolution, temperature profile and solids reduction. Eight (8) runs were performed in 100 L insulated air-tight bioreactors under a dynamic air flow regime. The initial mixtures were prepared using dewatered wastewater sludge, mixed paper wastes, food wastes, tree branches and sawdust at various initial C/N ratios and moisture contents. According to empirical modeling, mixtures of sludge and food waste mixtures at 1:1 ratio (ww, wet weight) maximize degradability. Structural amendments should be maintained below 30% to reach thermophilic temperatures. The initial C/N ratio and initial moisture content of the mixture were not found to influence the decomposition process. The bio C/bio N ratio started from around 10, for all runs, decreased during the middle of the process and increased to up to 20 at the end of the process. The solid carbon reduction of the mixtures without the branches ranged from 28% to 62%, whilst solid N reductions ranged from 30% to 63%. Respiratory quotients had a decreasing trend throughout the composting process. [Copyright &y& Elsevier]

Passive co-treatment of high-strength acid mine drainage (AMD) and municipal wastewater (MWW) was examined in a laboratory-scale, four-stage continuous flow reactor system with a total residence time of 6.6 d. Synthetic AMD of pH 2.60 and an acidity of 1,870 mg/L (as CaCO) was mixed at a 1:2 ratio with raw MWW (pH 7.67, 288 mg/L alkalinity (as CaCO), and 265 mg/L BOD) from the City of Norman, Oklahoma and introduced into the system. Alkalinity generated by limestone dissolution and bacterial SO reduction (BSR) processes was sufficient to support various metal removal processes and produce an effluent with circumneutral pH (6.98) and a net alkalinity of 10.4 mg/L (as CaCO). Alkalinity generation from limestone dissolution was comparable with conventional AMD passive treatment systems. BSR proceeded at a relatively high rate (0.56 mol/m day) despite inhibitory pH and metals concentrations. Results indicate that the diverse electron donors in the MWW may be as suitable for BSR and their supporting microbial communities as commonly used substrates, presenting an opportunity to use a common waste as a resource for passive treatment. [ABSTRACT FROM AUTHOR]

Potentially hazardous trace elements such as Cd, Cu, Cr, Ni and Zn are expected to accumulate in biosolids–amended soil and remain in the soil for a long period of time. In this research, uptake of metals by food plants including cabbage, carrot, lettuce and tomato grown on soils 10 years after biosolids application was studied. All the five metals were significantly accumulated in the biosolids-amended soils. The accumulation of metal in soil did not result in significant increase in concentrations of Cu, Cr and Ni in the edible plant tissues. However, the Cd and Zn concentrations of the edible tissues of plants harvested from the biosolids receiving soils were significantly enhanced in comparison with those of the unaffected soils. The plant uptake under Greenfield sandy loam soil was generally higher than those under the Domino clayey loam soil. The metal concentration of edible plant tissue exhibited increasing trends with respect to the concentrations of the ambulated metals. The extents of the increases were plant species dependent. The indigenous soil metals were absorbed by the plants in much higher rates than those of the biosolids–receiving soils. It appeared that the plant uptake of the indigenous soil-borne metal and the added biosolids-borne metals are independent of one another and mathematically are additive. [ABSTRACT FROM AUTHOR]

Coffee wastewater (CWW) is rich in organic mater and nutrients, but if applied in high doses, CWW may affect the soil sorptive complex balance and contaminate water tables through leaching process. This paper aims to evaluate the leachate composition and the chemical changes of the soil after application of increasing CWW doses. Therefore, CWW was applied in 12 PVC columns with 100 mm diameter and 800 mm height filled up with Yellow Latosolic Argisoil at doses of 1070 (control, dose 1), 214 (dose 2), 642 (dose 3) and,1070 mL (dose 4), corresponding to 1, 3 and 5 times the necessity of K (80g K2O plants-1) required by coffee tree in production. After CWW application, two leaching depths were applied, at 60 (sheet 1) and 75 days (sheet 2), using water and collecting leachate for further analysis of OCD, EC and soluble K, Na, Ca and Mg. After the incubation period, soil samples were collected 0-15; 15-30; 30-45 and 45-60 cm deep for electric conductivity of saturate paste extract (ECs) and pH in water (1:2,5) determination, along with K, Na, Ca e Mg analysis. CWW application in the soil changed the chemical characteristics of pH, ECs, K and Na. In leachate, there was variation in CE, K, Na, Ca and Mg related to incubation time. [ABSTRACT FROM AUTHOR]

We present the development stage of the sanitary landfills in Brazil in the context of urban solid residue management, demonstrating the necessity and importance of the employment of economic models. In the article, a cost estimate model is proposed as the basis for studies to be applied by sector management, including the city council, companies, consultants and engineers, contributing to the choice of new areas, public bids, municipal consortia and private public partnerships. [ABSTRACT FROM AUTHOR]

The disposal of industrial and sewage water is a problem of increasing importance throughout the world. In India, and most of the developing countries untreated sewage and industrial wastes are discharged on land or into the running water streams which is used for irrigating crops. These wastes often contain high amount of trace elements which may accumulate in soils in excessive quantities on long term use and enter the food chain through absorption by the plants. Among the trace metals, Cd has received the greater attention because of its easy absorption and accumulation in plants and animals to levels toxic for their health. The objective of this study conducted in three industrially different cities viz., Ludhiana, Jalandhar and Malerkotla was to monitor the extent of Cd accumulation in soils and plants receiving untreated sewage water. Plant and soil samples were collected from sewage and tubewell irrigated areas. Soil samples were analysed for texture, pH, EC, organic carbon (OC), CaCO3, bioavailable DTPA–Cd and plant samples were analysed for total Cd. In sewage irrigated soils, the mean values of pH were lower but organic carbon and electrical conductivity were generally higher both in surface and sub-surface layers of all the three cities as compared to tubewell irrigated soils. The mean DTPA- extractable Cd in sewage irrigated soil was 6.3- and 4.36-fold in Ludhiana, 3.38- and 1.71-fold in Jalandhar and 3.35- and 6.67-fold in Malerkotla in 0–15 and 15–30 cm soil depth, respectively, compared with the values in tubewell irrigated soils. The accumulation of DTPA–Cd in sewage irrigated soils was restricted to 30 cm depth after which the values were generally close to values in tubewell irrigated soils. Soil pH, OC, CaCO3, clay and silt collectively accounted for 37.1%, 65.1% and 53.9% DTPA-extractable bioavailable Cd in soils of Ludhiana, Jalandhar and Malerkotla, respectively. Lower R2 values in Ludhiana suggest that factors other than the ones mentioned may be affecting Cd availability. At all sites plants receiving sewage irrigation had elevated levels of Cd as compared to the plants receiving tubewell irrigation. The mean Cd content of sewage irrigated plants irrespective of the city was 5.96 μg g − 1 dry matter as compared to 0.98 μg g − 1 dry matter in tubewell irrigated plants. The results suggest that the intake of Cd obtained from consumption of crops grown on sewage irrigated soils would be much higher than the tolerable limits set by WHO and may, therefore, prove potentially toxic leading to various health ailments to humans and animals. [ABSTRACT FROM AUTHOR]

Soil often becomes contaminated with a variety of chemicals due to leakage of under/aboveground chemical storage tanks, improper discharge of waste, or improper design of waste containment facilities. Contaminated soil water can influence the soil's behavior seriously. Mineralogical alterations play a vital role in such circumstances. This paper describes the impact of varying concentrations of sulfuric acid solutions on the swell behavior of expansive soil containing predominantly montmorillonite. Using the conventional oedometer tests, the swell behavior of soil compacted with water inundated with acid solutions was studied. The soil swell, which is about 2% in water, increases to about 9% with 1N and to 50% with 4N acid solutions. The induced swell in acid solutions is attributable to mineralogical changes. The formation of new minerals and their associated fabric changes are investigated by scanning electron microscopy, X-ray diffraction, and energy dispersive analysis of X-ray on soil samples treated with sulfuric acid. While minerals like gypsum and kornelite are formed in the presence of 1N sulfuric acid, aluminite and chloritoid are formed in the presence of 4N sulfuric acid. These types of alterations are known to occur in iron sulfate minerals and are also found on Mars. The mechanism of mineralogical alterations is presented. [ABSTRACT FROM AUTHOR]

There is a growing concern over the potential accumulation of heavy metals in soils owing to rapid industrial and urban development and increasing reliance on agrochemicals in the last several decades. These metals can infiltrate through the soil thereby causing groundwater pollution. Surface soil samples (5 to 15 cm) collected from southeastern part of Ranga Reddy district were analyzed for 14 heavy metals (As, Ba, Co, Cr, Cu, Mo, Ni, Pb, Rb, Sr, V, Y, Zn and Zr) using Philips PW 2440 X-ray fluorescence spectrometer. Results for heavy and trace elements are reported for the first time in soils for this region. The contamination of the soils was assessed on the basis of enrichment factor (EF), geoaccumulation index ( I geo), contamination factor and degree of contamination. The results reveal that variations in heavy element concentrations in the soil analyzed have both geogenic and anthropogenic contribution, due to the long period of constant human activities in the study area. The concentration of the metals Ba, Rb, Sr, V, Y and Zr were interpreted to be mainly inherited from parent materials (rocks) and the As, Co, Cr, Cu, Mo, Ni, Pb and Zn concentrations show contribution from geogenic and anthropogenic sources. The major element variations in soils are determined by the composition of the parent material predominantly involving granites. [ABSTRACT FROM AUTHOR]

Septic tank systems are an important source of NO3 − to many aquifers, yet characterization of N mass balance and isotope systematics following septic tank effluent discharge into unsaturated sediments has received limited attention. In this study, samples of septic tank effluent before and after transport through single-pass packed-bed filters (sand filters) were evaluated to elucidate mass balance and isotope effects associated with septic tank effluent discharge to unsaturated sediments. Chemical and isotopic data from five newly installed pairs and ten established pairs of septic tanks and packed-bed filters serving single homes in Oregon indicate that aqueous solute concentrations are affected by variations in recharge (precipitation, evapotranspiration), NH4 + sorption (primarily in immature systems), nitrification, and gaseous N loss via NH3 volatilization and(or) N2 or N2O release during nitrification/denitrification. Substantial NH4 + sorption capacity was also observed in laboratory columns with synthetic effluent. Septic tank effluent δ 15N–NH4 + values were almost constant and averaged +4.9‰±0.4‰ (1 σ). In contrast, δ 15N values of NO3 − leaving mature packed-bed filters were variable (+0.8 to +14.4‰) and averaged +7.2‰±2.6‰. Net N loss in the two networks of packed-bed filters was indicated by average 10–30% decreases in Cl−-normalized N concentrations and 2–3‰ increases in δ 15N, consistent with fractionation accompanying gaseous N losses and corroborating established links between septic tank effluent and NO3 − in a local, shallow aquifer. Values of δ 18O–NO3 − leaving mature packed-bed... [Copyright &y& Elsevier]

The present study was conducted to determine the heavy metal contamination in soil with accumulation in plants in waste water irrigated areas. Results revealed that waste water contained lower concentrations of Cr, Zn, Cu, and Pb except Cd (0.03) than the permissible limits prescribed by the World Health Organization. The maximum metal concentrations occurred in Brassica oleracea (Zn 63.80, Cu 12.25, Cr 10.65, Pb 3.63, and Cd 0.56 mg Kg-1).The metal enrichment (EF of Cd 1.9, Cr2.9, Zn 4.8, Cu 6.5, and Pb 15.5) and degree of contamination (CF of Cd 2.9, Cr 2.0, Zn 2.3, Cu 2.7, and Pb 2.2) showed that accumulation of the five toxic metals increased during sewage irrigation as compared with the reference values, other Indian regions and globally. However, based on WHO standards for heavy metal contamination of soil and irrigation water, our data does not ensure safe levels for food. [ABSTRACT FROM AUTHOR]

It is often assumed that soils are homogeneous when designing septic systems or modeling wastewater flow from their trenches. The main objective of this study was to assess water infiltration and movement from the trenches similar to the ones commonly used for on-site wastewater dispersal by septic systems. Four separate experiments, each using a small drainfield with four parallel trenches, were conducted at three sites with different soils. In two experiments the trenches were in the coarse-textured soil above a clayey Bt horizon. In the other two experiments the trenches were in the Bt horizon. For each experiment, 50 L of a solution containing potassium bromide and brilliant blue FCF (as a tracer dye) were applied once a day to each trench for 14 or 15 days. A sampling pit was dug perpendicular to the trenches after the tracer solution application, and the distribution of the tracer dye and Br- around the trenches on the two walls of the pit were assessed. Tracer solution infiltration from the trenches was not uniform in any of the experiments. Water flow in the Bt horizon was mainly through macropores. Further, water containing Br- and dye moved a substantial distance from the trenches through macropores when trenches were installed in the Bt horizon. When trenches were installed in the coarse-textured soil above the Bt horizon, most of the tracer solution moved away laterally from the drainfield through the zone above the Bt horizon. Overall, the results indicate that soil morphological properties and soil horizonations, as well as the nature of water movement from trenches must be considered when modeling water flow from septic system trenches or when designing septic system drainfields. [ABSTRACT FROM AUTHOR]

On-site wastewater systems (OWS) provide a sustainable method for disposing of residential wastewater. Large “cluster” OWS systems are now frequently being used to serve multiple-unit housing developments. Groundwater perching, mounding, and lateral flow can occur when the effluent application rate to an infiltration area exceeds the soil’s capacity to infiltrate the wastewater. This study addresses mounding of wastewater on a low hydraulic conductivity (K) layer in the vadose zone, and focuses on modeling tools available to design systems so that the potential for the occurrence of surface or side-slope breakout is minimized. In particular, we demonstrate how an existing analytical model developed by Khan et al. (1976) can be used for evaluating the mounding problem. The robustness and limitations of the analytical solution due to certain constraining assumptions are evaluated for a few realistic scenarios by comparing it to results of a numerical model that is not constrained by the assumptions. The height and extent of mounding depends on both the hydraulic conductivity of the soil below the infiltration field, as well as the K value of the low-permeability layer. The numerical modeling demonstrates that the analytical solution is more accurate for the case of a thick low-K layer, and for conditions that represent a deep water table, because these conditions are more closely aligned with the conceptual model that the analytical solution derivation is based on. The analytical solution is less accurate for cases of a shallow water table, or a thin low-K layer. Mounding is smaller for thin low-K layers and for deep water tables. In general, it is shown that the analytical model is a conservative predictor for mounding for several reasons. First, it does not consider the capacity of the vadose zone to conduct infiltrating water laterally. Second, nonuniformities in a low-permeability layer (e.g., breaks in the layer) tend to reduce the mounding compared to the uniform layer assumed by the analytical solution. Third, anisotropic soils, where the vertical K is less than the horizontal K (a typical case), exhibit a smaller mounding height and lateral extent of mounding than predicted by the analytical solution. Measurement or accurate estimation of hydraulic conductivity values for subsurface soil layers is necessary for both analytical and numerical models if an accurate assessment of mounding is desired. [ABSTRACT FROM AUTHOR]

Land application of wastes generated from concentrated animal feeding operations may result in accumulation of tetracyclines (TCs) and metals in agricultural soils. Adsorption of TCs and metals on soil minerals strongly affects their mobility. This study was conducted to evaluate the interaction between tetracycline (TC) and Cu(II) with regard to their adsorption and cosorption on montmorillonite as affected by solution pH. When solution pH was below 6.5, the presence of TC increased Cu(II) adsorption on montmorillonite, which could be due to increasing Cu(II) adsorption via the TC bridge, or due to the stronger affinity of TC-Cu(II) complex to the mineral than Cu2+ ion itself. Zeta potential of the montmorillonite significantly decreased after the adsorption of TC, suggesting a strong interaction between TC and montmorillonite. Addition of Cu(II) ions increased TC adsorption on the mineral in a wide range of pH. The experimental data were well fit with the weighted sum model. The complexes of TC and Cu(II) (CuH2L2+, CuHL+ and CuL) had higher sorption coefficients (Kd) than that of the corresponding TC species (H3L+, H2L, and HL-). Increasing adsorption of TC and Cu(II) on montmorillonite as they coexist in the normal pH environment may thus reduce their mobility. [ABSTRACT FROM AUTHOR]

The identification of uncontrolled landfills is a central environmental problem in all developed and developing countries, where several illegal waste deposits exist as a result of rapid industrial growth over the past century. Remote sensing can potentially provide crucial information for the identification of contaminated sites, but surprisingly there is a marked lack of rigorously validated approaches. In this paper we introduce and validate a method that uses remotely sensed information and a geographic information system (GIS) to identify unknown landfills over large areas. The method is applied to a study area located in NE Italy (part of the Venice lagoon watershed) using IKONOS satellite data. Soil contamination effects on the radiometric properties of vegetation, calibrated using spectral signatures of stressed vegetation from known illegal landfill sites, were used to define numerous candidate sites that are most likely to host waste materials. Distributed geographical information, such as the position of the road network, the population density, and historical aerial photographs, have then been used to select the most likely contaminated sites among the candidates identified through remote sensing. The importance of the integration of GIS and remote sensing is highlighted and represents a key instrument for environmental management and for the spatially distributed characterization of possible uncontrolled landfill sites. [ABSTRACT FROM AUTHOR]

Sewage sludge, also referred as biosolids, is a byproduct of sewage treatment processes. Land application of sewage sludge is one of the important disposal alternatives. Characteristics of sewage sludge depend upon the quality of sewage and type of treatment processes followed. Being rich in organic and inorganic plant nutrients, sewage sludge may substitute for fertilizer, but availability of potential toxic metals often restricts its uses. Sludge amendment to the soil modifies its physico-chemical and biological properties. Crop yield in adequately sludge-amended soil is generally more than that of well-fertilized controls. Bioavailability of metals increases in sludge amended soil at excessive rates of application for many years. Plants differ in their abilities to absorb sludge-derived metals from the soil. The purpose of this paper is to review the available information on various aspects of sewage sludge application on soil fertility and consequent effects on plant production to explore the possibility of exploiting this byproduct for agronomy and horticulture. [Copyright &y& Elsevier]

Abstract: The atmospheric concentrations and emission rates of CH4 and CO2 were studied at three sites of the Fu-Der-Kan closed landfill and after as the multi-use recreational park in northern Taiwan. Atmospheric CH4 and CO2 concentrations of closed landfill were 1.7–4.6 and 324–409ppm, respectively. CH4 and CO2 emission rates ranged from 8.8 to 163mgm−2 h−1 and from 495 to 1531mgm−2h−1, respectively. Diurnal variation was noted with higher values at night than those in daytime. After creation of the park, atmospheric CH4 and CO2 concentrations were 1.8–3.1 and 332–441ppm, respectively. CH4 and CO2 emission rates ranged from −1.1 to 2.3mgm−2 h−1 and from −135 to 301mgm−2 h−1, respectively. There were no notable diurnal variations in either atmospheric concentrations or emission rates. [Copyright &y& Elsevier]

Remediation for contaminated farm soil had become an important task in Taiwan for the authorities because many farms had been contaminated with heavy metals due to illegal discharges of industrial wastewater. A comprehensive and effective remediation methodology for heavy metal-contaminated farm soil was presented in Taiwan, which integrated assessment of soil contamination and environmental characteristics, remediation technology, and performance assessment. Turnover and attenuation method was chosen and applied in this study based on assessment criteria of social, technological, economical, and environmental feasibilities. However, there were some difficulties needed to be solved when turnover and attenuation method was applied because of great variation of environmental characteristics in Taiwan. A sustainable management framework based on Managing for Results method was therefore developed for guiding the accomplishment of the remediation tasks. Three contaminated sites had been successfully completed for the remediation tasks in this study by using the proposed integral methodology. The distribution of heavy metal concentrations in soils and environmental characteristics had been predicted using the proposed rule for determining adequate number and locations of sampling points and used to calculate the excavation depth for each area. The results of performance measurements showed that the farm lands had recovered their agricultural utility to meet the landowners' request, heavy metal concentrations in the soils had been reduced with proper attenuation ratio, remediation cost had been controlled in the range of the budget, and heavy metal concentrations in the soils and crops after remediation can meet the regulatory limits. The comprehensive and effective remediation methodology could be employed to assure the effectiveness and efficiency of the remediation tasks based on the principles of sustainable development, as observed from the analytical results of the three contaminated cases. [ABSTRACT FROM AUTHOR]

Leachate samples from a sanitary landfill of Araraquara city and composting usine of Vila Leopoldina, São Paulo, Brazil were lyophilized to remove the water content. TG/DTG curves at different heating rates were recorded. The second step of the thermal decomposition of leachate from the Araraquara landfill (CB1), from the composting usine from Vila Leopoldina (CB2) from the organic phase extracted (FO) and aqueous phase (FA) were all kinetically evaluated using the non-isothermal method. By Flynn-Wall isoconversional method the following values were obtained: E=234±3.65 kJ mol−1 and log A=29.7±0.58 min−1 for CB1; E=129±1.66 kJ mol−1 and log A=11.8±0.10 min−1 for CB2; E=51.6±1.35 kJ mol−1 and log A=6.09±0.09 min−1 for FO and E=76.91±6.33 kJ mol−1 and log A=8.88±0.7 min−1 for FA with 95% confidence level. Applying the procedures of Málek and Koga, SB kinetic model (Šesták-Berggren) is the most appropriate to describe the decomposition of CB1, CB2, FO and FA. [ABSTRACT FROM AUTHOR]

In this study, several columns of different lengths were filled with composite soils sampled from the field at corresponding depths and then loaded intermittently with influent of a high phosphorus concentration to evaluate phosphorus fate and transport in soil. The results indicate that the height of the mass transfer zone, solvent pore velocity, and soil's life expectancy for phosphorus removal increased with depth, while the retained phosphorus per kilogram of soil and the linear adsorption equilibrium coefficient, R, decreased with depth. An equation was developed to link liquidphase phosphorus with solvent traveling time and soil depth. The results of X-ray diffraction and washout tests indicate that calcium-phosphorus precipitation and/or crystal growth occurred in the columns. The new protocol is useful for evaluation of phosphorus fate and transport in other subsurface systems, because it allows flexible adjustments in hydraulic loadings, feed solution, and sampling schemes. Water Environ. Res., 79, 2343 (2007). [ABSTRACT FROM AUTHOR]

Among the most common non-conventional wastewater treatment techniques used in the Czech Republic are waste stabilisation ponds (WSP), subsurface horizontal flow constructed wetlands (CW) and vertical flow groundfilters (GF). These extensive systems can be advantageously used for treatment of waters coming from sewerages where the ballast weighting commonly makes more than half of dry-weather flow. The monitoring was focused at 14 different extensive systems. Organics removal efficiencies were favourable (CW-82%; GF-88%); in the case of WSP only 57% due to the algal bloom. Total nitrogen removal efficiencies were 43 and 47% for WSP and GF; in the case of CW only 32% due to often occurring anaerobic conditions in filter beds. Total phosphorus removal efficiencies were 37, 35 and 22% for WSP, GF and CW, respectively. Often occurring problems are the ice-blockage of surface aerators at WSP during wintertimes, the pond duckweed-cover or the algal bloom at WSP during summers; a gradual colmatage of filter systems; and the oxygen deficiency in beds of subsurface horizontal flow constructed wetlands. Czech legal regulations do not allow treated wastewater disposal into underground waters. There is only an exception for individual family houses. Up to now, knowledge gained by monitoring of a village (which uses the infiltration upon a permission issued according to earlier legal regulations) have not shown an unacceptable groundwater quality deterioration into the infiltration areas. [ABSTRACT FROM AUTHOR]

Surface soil samples were collected from 52 sites around Guanting Reservoir in Beijing, China, and contents of ‘total’ metals (Cu, Zn, Pb, Cd, As, Ni and Cr) were determined. The results indicate that the degree of heavy metal pollution in the soils declines in the order of Cd>Cr>Zn>As>Cu>Ni>Pb. Based on the results of a combination of multivariate statistics and geostatiscal analyses, it was concluded that land application of phosphate fertilizer, wastewater and sludge were the primary sources of Cd and Zn in soils. Whereas As, Cu, Cr and Ni in some soils were due to natural rock weathering. The sources of Pb in soils only partially originated from land application of phosphate fertilizer, but mainly from vehicle exhaust. The greatest concentrations of all metals, except for Pb, were found in Huailai County and the towns of Yanghedaqiao and Guanting. [Copyright &y& Elsevier]

Simple models based on the physical and biochemical processes occurring in septic tanks, pit and urine diversion latrines were developed to determine the nutrient flows in these systems. Nitrogen and phosphorus separation in different output materials from these on-site sanitation installations were thus determined. Moreover, nutrient separation in septic tanks was also assessed through literature values and by eliciting expert judgement. Use of formal expert elicitation technique proved to be effective, particularly in the context of developing countries where data is often scarce but expert judgement readily available. In Vietnam, only 5–14% and 11–27% of the nitrogen and phosphorus input, respectively, are removed from septic tanks with the faecal sludge. The remaining fraction leaves the tank via the liquid effluent. Unlike septic tanks, urine diversion latrines allow to immobilise most of the nutrients either in form of stored urine or dehydrated faecal matter. These latrines thus contribute to reducing the nutrient load in the environment and lowering consumption of energy and non-renewable resources for fertiliser production. [Copyright &y& Elsevier]

Contamination with heavy metals and microbes of roots of Valerian (Valeriana officinalis L.) grown in either unamended soil (US) or sewage sludge-amended soil (SSAS) were studied in two seasons in the UK. The concentrations of heavy metals found in the washed roots from SSAS were greater than the concentrations found in roots from the US plots by 480, 2800, 215, 1900, and 82% (in 2002) and 234,446, 187,426, and 450% (in 2004) for cadmium, chromium, copper, lead, and zinc, respectively. Drying reduced the levels of coliforms, and washing treatments also tended to reduce the levels of microorganisms (Clostridia, molds, Bacillus sp.) detected on dried roots. [ABSTRACT FROM AUTHOR]

In this study, the presence, composition, and concentrations of organic wastewater contaminants (OWCs) were determined in solid materials produced during wastewater treatment. This study was undertaken to evaluate the potential of these solids, collectively referred to as biosolids, as a source of OWCs to soil and water in contact with soil. Nine different biosolid products, produced by municipal wastewater treatment plants in seven different states, were analyzed for 87 different OWCs. Fifty-five of the OWCs were detected in at least one biosolid product. The 87 different OWCs represent a diverse cross section of emerging organic contaminants that enter wastewater treatment plants and may be discharged without being completely metabolized or degraded. A minimum of 30 and a maximum of 45 OWCs were detected in any one biosolid. The biosolids used in this study are produced by several production methods, and the plants they originate from have differing population demographics, yet the percent composition of total OWC content, and of the most common OWCs, typically did not vary greatly between the biosolids tested. The summed OWC content ranged from 64 to 1811 mg/kg dry weight. Six biosolids were collected twice, 3-18 months apart, and the total OWC content of each biosolid varied by less than a factor of 2. These results indicate that the biosolids investigated in this study have OWC compositions and concentrations that are more similar than different and that biosolids are highly enriched in OWCs (as mass-normalized concentrations) when compared to effluents or effluent-impacted water. These results demonstrate the need to better describe the composition and fate of OWCs in biosolids since about 50% of biosolids are land applied and thus become a potentially ubiquitous nonpoint source of OWCs into the environment. [ABSTRACT FROM AUTHOR]

Linear alkylbenzene sulphonates (LASs) are anionic surfactants commonly used in commercial detergents. A potential risk associated with the recycling of sewage waste materials is the presence of LASs and their primary degradation products, which could accumulate in sludge, especially during anaerobic processing. The long‐term accumulation of these contaminants in soils and especially the potential disturbance of soil functions need to be studied in more detail. In our study, the influence of the amendment added to an agricultural soil with different organic wastes containing LASs on organic matter content and nitrogen (N) content evolution and mineralization was studied in field conditions. A completely randomized 3×3 factorial arrangement, representing two sewage sludge types (composted and uncomposted) and three levels of LAS presence (0, 15, and 30 g/m2) in treated soils, was established using field plots (7×2 m); the results are compared with untreated plots. Statistical models based on covariance analysis were used to understand the dynamics of and the main factors influencing carbon (C) and N mineralization in sewage sludge amended–soils in the presence of LAS. LAS seemed to alter nitrogen mineralization, especially the nitrate dynamics. [ABSTRACT FROM AUTHOR]

Lead removal from water and contaminated soils was investigated using biosurfactant, anionic, and nonionic surfactants in continuously stirred batch reactors. Lead-contaminated water up to 100 mg/L and clay soil up to 3,000 mg/kg were used in this investigation. The surfactant concentration up to 10 critical micelle concentration was used. The speciation of lead into the micelles was quantified and the lead removal efficiency depended on the level of contamination, surfactant type, and concentration. Of the surfactants used, biosurfactant (produced from used vegetable oil) had the best removal efficiency (75%) at a lead contamination of 100 mg/L in water at pH of over 12. The Fourier-transformed infrared spectroscopy study showed that the carboxyl group in the biosurfactant was effective in removing the lead from the solution. Langmuir and Freundlich relationships were used to represent the micelle partitioning of lead in the surfactant solutions. Desorption of lead from contaminated kaolinite clay was represented using linear isotherms. The biosurfactant solution had a higher micelle partitioning for the lead from contaminated water and desorbing the lead from the contaminated soil compared to the other chemical surfactants. [ABSTRACT FROM AUTHOR]