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1.
In this article, for the treatment of two specific pharmaceutical waste solvents the resource consumption of an on-site distillation process is evaluated and compared with an off-site incineration process. Both techniques are evaluated based on a thermodynamic quantitative method. The exergy approach and the cumulative exergy extracted from the natural environment (CEENE) are envisaged in order to evaluate the overall resource intake at different levels. Scenarios are constructed to make a fair comparison of both techniques. Two waste solvents, toluene (TOL) and dichloromethane (DCM), from the pharmaceutical industry which are frequently sent to distillation were evaluated. The functional unit for the comparison of both treatment alternatives is the treatment of 1 kg waste solvent + the incineration of W kg low calorific hazardous waste + the delivery of X kg “recovered” solvent + the production of Y MJ heat and Z MJ electricity. W, X, Y and Z depend on the waste solvent properties. In terms of resource requirements, distillation requires 17% (TOL) and 66% (DCM) less resources than incineration. It can be concluded that the waste solvent properties, the efficiency of the distillation process and the efficiency of the fresh solvent production process are of major importance on the resource consumption and the final choice between incineration and distillation. For a full environmental impact analysis of both treatment options, also the emissions should be taken into account. It also has to be stressed that in practice, only solvents go to incineration which cannot be distilled due to the type and degree of pollution/composition of the solvent. If distillation is not feasible, then such solvents are sent to incineration with energy recovery, according to the EU directive 2006/12/EG.  相似文献   

2.
Separation of water for reuse is essential in an effluent treatment system, especially in activities with high water consumption, such as a pig production system. The objective of this work was to evaluate the efficiency of Tanfloc SG® coagulant tannin/organic flocculant used to treat effluent generated during the intensive rearing of swine. For the evaluation, laboratory and in situ tests (field test) were performed. The laboratory tests were performed to define the concentration (1 and 16%), dosage (0, 0.1, 0.2, 0.3, 0.4, 0.5, 1.0, 2.0, 4.0, 8.0, and 16.0 milliliters of the solution), and time (24, 48, 72, and 96 hours) of coagulation/flocculation treatment of the solid portion of the effluent. The parameters pH, turbidity, oxidation reduction potential, dissolved oxygen, and electroconductivity (in microsiemens per centimeter) were evaluated using a multiparameter probe and the parameters ammonia (NH3), nitrate (NO3), and nitrite (NO2) in the laboratory, in relation to the coagulation/flocculation time of the solid part of the effluent. The use of tannin as a coagulant/flocculant of plant origin in the treatment of swine effluents was effective in reducing turbidity and concentrations of ammonia, nitrite, and nitrate, and it allowed separation of the solid–liquid phase in approximately 68% as liquid phase.  相似文献   

3.
ABSTRACT: A laboratory boat designed to investigate toxic effects on site and its use as a bioassay tool in the study of a refinery effluent discharged into the Schuylkill River, a tributary of the Delaware River, is described. Three-hundred thirty-six-hour continuous-flow bioassay s exposing the bluegill sunfish, the channel catfish, the tadpole snail, the grass shrimp, and the sheephead minnow to concentrations of refinery effluent in Schuylkill, Delaware River, and Delaware Bay water, with and without the addition of sediment were performed. Results indicated that the toxicity (lethality) of fresh samples tested aboard the boat (refinery effluent, dilution water, sediment) were considerably higher (i.e., refinery effluent at full strength was 2.2X as lethal to the bluegill, 1.4X as lethal to the channel catfish, 1.5X as lethal to the sheep-head minnow and 100X as lethal to the grass shrimp) than the same test material collected from the refinery outfall and brought to a central laboratory for testing. Chemical analysis and bioassay data is presented showing the effects of aging and irradiation upon the refinery effluent.  相似文献   

4.
This study tested the hypotheses that (1) exposure to treated Water Reclamation Plant (WRP) effluent will induce biological effects in exposed fish that are consistent with environmental estrogen (EE) exposure; and (2) seasonal differences in effluent composition will moderate biological effects. We conducted seven on‐site exposures using a mobile laboratory. Total estrogenicity of effluents was 10‐ to 20‐fold higher during spring than in fall. Common EEs including steroid estrogens, alkylphenols, and bisphenol‐A were ubiquitous. An unusual spike in total estrogenicity identified a combined sewer overflow event. Fathead minnows (Pimephales promelas) responded to exposure with subtle changes in vitellogenin concentrations and secondary sex characteristics. An opportunity to assess a common carp (Cyprinus carpio) population permanently sustained inside the Stickney WRP revealed pronounced exposure effects, but also the resilience of biological organisms even under long‐term exposure. In contrast to other studies, no histopathological changes were found. The mobile exposure laboratory proved capable of maintaining U.S. Environmental Protection Agency‐recommended exposure conditions while providing flexibility for rapid deployment at multiple sites with minimal operational disruption. Further studies using this platform hold promise to resolve the convoluted interactions between complex effluents and inherent biological complexity.  相似文献   

5.
Recycling and conservation efforts for water are the need of the day because of the lack of new water sources and the ever-increasing demand for drinking water. Seedlings of Acacia nilotica L. were irrigated with: canal water (T1, control); municipal effluent (T2); textile effluent (T3); steel effluent (T4); textile + municipal effluent in 1:1 ratio (T5); steel + municipal effluent in 1:2 ratio (T6); steel + textile in 1:2 ratio (T8) and steel + municipal + textile in 1:2:2 ratio (T7) with views to observe effluents effect on the seedlings and its adaptability and to recommend safe disposal of these effluents. Seedlings in T6, T7 and T8 showed 50% lesser height and collar diameter than those in control. Seedlings in T2 attained greatest height, collar diameter, numbers of branches and produced 140 g dry biomass seedling−1. Highest concentration of manganese (Mn), iron (Fe), copper (Cu) and zinc (Zn) and lowest concentration of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca) and magnesium (Mg) in the seedlings of T4, T6, T7 and T8 resulted in nutritional imbalance, mineral toxicity and reduction in photosynthetic (Pn) and transpiration (E) rates and caused seedling mortality. Seedlings of T3 had highest sodium concentration and low concentration of Ca, Mg and micronutrients resulting in nutritional imbalance, augmented chlorosis and reduced gas exchange and biomass by half as compared to control. Increased growth, Pn and E and biomass in seedlings of T5 over T3 and survival period in T6, T7 and T8 seedlings suggested a beneficial effect of effluents mixing. Unscientific disposal should be avoided and toxic concentration of metal ions␣may be reduced for long-term application and harmless disposal of effluents in afforestation and urban development.  相似文献   

6.
The use of domestic effluents for the irrigation of crops has been widespread in Israel for the past 30 years. The sodium adsorption ratio (SAR) of the standardized domestic effluents ranges between 4 and 6. According to the literature, when soils with SAR levels of 4 to 6 are exposed to direct raindrop impact they are subjected to enhanced aggregate disintegration, leading to sealing processes of the soil surface and subsequent increased runoff and soil erosion. However, these phenomena were not observed in the laboratory and field experiments of this study. On the other hand, a rapid decrease of the soil SAR to its initial values was observed, in laboratory and fieldwork, once the soil was subjected to a simulated rainstorm of distilled water (laboratory) or natural rainstorms (field plots). We can conclude that the process of SAR increase during irrigation with standardized effluent water is reversible. Further investigation in this direction can lead to recommendations regarding the necessary levels of domestic sewage water purification in correlation with soil types, climatic conditions, and hazards to tap water aquifers.  相似文献   

7.
Sewage effluent for land application is becoming an increasingly important source of irrigation water in many semi-arid regions of the world. Two main approaches to the use of sanitation to upgrade effluent for reuse in agriculture were analyzed: (i) sanitizing to the level required for each crop; or (ii) upgrading all effluent to the sanitary level mandated for unrestricted irrigation (<10 fecal coli/100mL). The first approach was authorized by the Israeli health authorities, who consider irrigation with secondary effluent to be complementary to the treatment process. The other approach was conceived mainly by the agricultural and environmental establishments, which debited the additional financial burden to the urban sector and/or the 'general public'. We show that upgrading all effluents in Israel to 'unrestricted irrigation quality' would cost $69 million each year for upgrading alone, in addition to the costs of treatment to the sanitary level required for each individual crop and of observing all the necessary additional precautions and boundaries. This difference in cost stems from the fact that most effluent is used for the irrigation of non-edible crops, for which partial pathogen removal is sufficient. Thus, upgrading to the sanitary level required by the most sensitive crops would be rather wasteful.  相似文献   

8.
Wood processing effluents contain different types of phenolic compounds, from simple monomers to high molecular weight (MW) polyphenolic polymers, that can inhibit wastewater treatment. This work presents a comparative study of the methanogenic toxicity produced by three wood processing effluents (hardboard, fiberboard and BKME (kraft mill effluent)) using Pinus radiata, Eucalyptus and Tepa as feedstock (the last one being a native Chilean tree species). This study evaluates the influence of non-adapted granular and adapted flocculent sludge on forest industrial wastewater treatment as well as continuous anaerobic biodegradation of hardboard processing effluent using the upflow anaerobic sludge blanket (UASB). The adapted biomass (flocculent sludge) did not show any lag-phase signs. The 50% IC (the concentration causing 50% inhibition of methanogenic activity) was 4.3 g COD-effluent (chemical oxygen demand (COD)-of the effluent)/l and 2.8 g COD-effluent/l for the flocculent sludge and the granular sludge, respectively. The UASB system worked at low organic load rates (0.1-0.4 g COD/l d) with the COD removal ranging between 10 and 30%, and color removal did not occur under anaerobic conditions due to high MW. Indeed, the MW analysis indicates the presence of phenolic compounds over 25,000 Da in the anaerobic effluent.  相似文献   

9.
Tannery effluents and relevant ground water and soil samples collected from various tanning industries of Peshawar were analyzed for Na, Ca, K, Mg, Fe, Mn, Cr, Co, Cd, Ni, Pb and Zn by the AAS method. The metal concentration data for the three media are reported in terms of basic statistical parameters, metal-to-metal correlations and linear regression analyses. Metal distributions in the three media were quite divergent and showed non-normal distributions with high standard deviation and skewness parameters. Sodium exhibited the highest mean levels of 1,277mg/L, 881mg/L and 12,912mg/kg in the effluent, ground water and soil samples, respectively. Among other metals, Cr concentrations were 410mg/L, 0.145mg/L, 100mg/kg and Ca, 278mg/L, 64.8mg/L, and 2,285mg/kg in the effluent, ground water and soil samples, respectively. Some significant correlations were observed between effluent and soils in terms of Na, Cr, Ni, Co and Pb. The ground water-soil interrelationship suggested that Na levels in the soil and ground water were significantly correlated with each other (r=0.486, P<0.01). Similarly, Cr in the soil is strongly correlated with Ca in ground water (r=0.486, P<0.01). These results were duly supported by the linear regression analysis of data. The source identification studies conducted using Principal Component Analysis (PCA) and Cluster Analysis (CA) evidenced that ground water and soil were being contaminated by the toxic metals emanating from the tannery effluents.  相似文献   

10.
 Effluents from pigment manufacturing operations contain highly toxic substances. These substances in their pure form are highly valuable industrial raw materials and their loss in the effluents is not only a pollution problem but also one implying economic loss. This article describes an approach, which highlights a policy that can allow elimination of a pollution problem with simultaneous economic benefits through recovery of the pollutants in readily marketable forms. This approach converts serious "liabilities into substantial assets" and is worth adopting in many cases. The case considered here is that of the effluent from a plant manufacturing the pigment, phthalocyanine green (PG). This effluent is highly acidic and contains copper and aluminium in chloride form. There is a serious disposal problem concerning this effluent. The work reported here was focussed on recovering the metal values in this effluent in a form which can be readily marketed. Particularly important is the fact that the aluminium value can be recovered in the form of zeolite 4A, which is an environment friendly additive in modern detergent formulations. Received: 1 July 1998 / Accepted: 30 September 1998  相似文献   

11.
Color and chemical oxygen demand (COD) in bleach plant effluents are of concern. Acidified flyash can effectively remove both color and COD from caustic bleach plant effluents. Equally effective, but quicker and easier, is to acidify the effluent to approximately pH 1 and use untreated flyash. Based on maximum color removal, the required contact time is short, about 10 min, and the optimum ash dosage is that amount which raises the pH of the final effluent to about 5. Sufficient color removal is obtained to easily meet Maine's color regulations. Preliminary tests on samples of deionized water spiked with two arochlors of PCB showed high removal efficiency.The major cost of implementing and operating the cleanup procedure will be the cost of the required acid. This might be minimized by using some of the acidic (chlorine) effluent to lower the pH of the caustic effluent. This will, however, lead to less color reduction, and an unknown effect on the COD.  相似文献   

12.
Phytoremediation of dairy effluent by constructed wetland technology   总被引:1,自引:0,他引:1  
Constructed wetlands are artificial wastewater treatment systems consisting of shallow ponds or channels which have been planted with aquatic plants and which rely upon natural microbial, biological, physical and chemical process to treat wastewater and are gaining acceptance in the recent years as a viable option for the treatment of industrial effluents and removal of toxic components. In this study, an attempt was made to compare the efficiency of aquatic macrophytes like Typha sp., Eichhornia sp., Salvinia sp., Pistia sp., Azolla sp. and Lemna sp. to treat the effluents from dairy factory, under laboratory conditions in constructed wetlands. The biological oxygen demand and chemical oxygen demand of dairy effluent were reduced up to 65.4–83.07% and 70.4–85.3%, respectively, after treatment with constructed wetland technology.  相似文献   

13.
ABSTRACT: In 1983, the City of Indianapolis, Indiana, completed construction of advanced wastewater treatment (AWT) systems to enlarge and upgrade its existing Belmont Road and South port Road secondary treatment plants. A nonparametric statistical procedure, a modified form of the Wilcoxon-Mann-Whitney rank-sum test, was used to test for trends in water quality at two upstream and two downstream sites on White River and at the two treatment plants. Results comparing the pre- (1978–1980) and post- (1983–1986) AWT periods show statistically significant improvements in the quality of the treated effluent and of the White River downstream from the plants. Water quality at sites upstream from the city was relatively constant during the period of study. Total ammonia (as N) decreased 14.6 mg/L and BOD5 (five-day biochemical oxygen demand) decreased 10 to 19 mg/L in the two effluents. Total ammonia in the river downstream from the plants decreased 0.8 to 1.9 mg/L and BOD5 decreased 2.3 to 2.5 mg/L. Nitrate (as N) increased 14.5 mg/L in the plant effluents and 2.0 to 2.4 mg/L in the river because of in-plant nitrification. Dissolved oxygen concentration in the river increased about 3 mg/L because of reduced oxygen demand for nitrification and biochemical oxidation processes.  相似文献   

14.
Hospital effluents are loaded with pathogenic microorganisms, partially metabolized pharmaceutical substances, radioactive elements, and other toxic substances. Such effluents if not treated properly can damage the natural environment and create a biological imbalance. This paper points out the areas of concern for hospital wastewater disposal and reports the findings of a limited physico-chemical study of treatment options for hospital effluents conducted at Christian Medical College and Hospital, Vellore, Tamil Nadu. The effluent collected was checked for conventional parameters and subjected to coagulation experiments. The raw and settled effluents were coagulated with FeCl(3), filtered and disinfected. Physico-chemical treatment seems to be an attractive option for the cost-effective disposal of hospital effluents. The results of this study call for further detailed study in this area.  相似文献   

15.
Recycling of kitchen garbage is an urgent task for reducing public spending and environmental burdens by incineration and/or landfill. There is an interesting regional effort in Ogawa, Saitama prefecture, Japan, in which source-separated kitchen garbage is anaerobically fermented with a biogas plant and the resultant effluent is used as a quick-release organic fertilizer by surrounding farmers. However, scientific assessments of fertilizer values and risks in the use of the effluent were lacking. Thus, a field experiment was conducted from 2003 to 2004 in Tohoku National Agricultural Research Center to grow spinach (Spinacia oleracea L.) and komatsuna (Brassica rapa var. perviridis L. H. Bailey) for evaluating the fertilizer value of the kitchen garbage effluent (KGE), nitrate, coliform group (CG), Escherichia coli, fecal streptococci (FS), and Vibrio parahaemolyticus concentrations of KGE and in the soil and the plant leaves. A cattle manure effluent (CME) and chemical fertilizers (NPK) were used as controls. Total nitrogen (N) and ammonium N concentrations of the KGE were 1.47 and 1.46 g kg(-1), respectively. The bacteria tested were detected in both biogas effluents in the order of 2 to 3 log CFU g(-1), but there was little evidence that the biogas effluents increased these bacteria in the soil and the plant leaves. At the rate of 22 g N m(-2), yield, total N uptake, apparent N recovery rate, and leaf nitrate ion concentration at harvest of spinach and komatsuna in the KGE plot were mostly comparable to those in the NPK and CME plots. We conclude that the KGE is a quick-release N fertilizer comparable to chemical fertilizers and does not cause contamination of CG, E. coli, FS, or V. parahaemolyticus in the soil and spinach and komatsuna leaves.  相似文献   

16.
Correlation curves were developed relating nephelometric turbidity units (NTU) with total suspended solids (TSS) for diked upland dredged material placement site effluents of three US Army Corps of Engineers (COE) maintenance dredging projects in the Chesapeake Bay, Maryland. The procedure was developed in an effort to ensure compliance with Maryland's 400 milligrams per liter (mg/l) TSS standard for COE dredging projects. Samples of the sediments to be dredged were collected and analyzed, correlating turbidity readings with TSS determined by standard gravimetric techniques. The correlation curves were provided to the COE inspectors to measure the effluent with a turbidity meter and to extract a TSS concentration from the correlation curve. Samples collected and analyzed after initiation of the dredging indicated that the correlation curves were an overestimate of the actual TSS concentrations of the effluent discharges. The procedure, endorsed by the State of Maryland, provided immediate on-site TSS analysis eliminating the previously encountered delays in obtaining gravimetric analysis of effluent discharges and potential contract management problems.  相似文献   

17.
Treatment of chemical industrial wastewater from building and construction chemicals factory and plastic shoes manufacturing factory was investigated. The two factories discharge their wastewater into the public sewerage network. The results showed the wastewater discharged from the building and construction chemicals factory was highly contaminated with organic compounds. The average values of chemical oxygen demand (COD) and biochemical oxygen demand (BOD) were 2912 and 150 mgO2/l. Phenol concentration up to 0.3 mg/l was detected. Chemical treatment using lime aided with ferric chloride proved to be effective and produced an effluent characteristics in compliance with Egyptian permissible limits. With respect to the other factory, industrial wastewater was mixed with domestic wastewater in order to lower the organic load. The COD, BOD values after mixing reached 5239 and 2615 mgO2/l. The average concentration of phenol was 0.5 mg/l. Biological treatment using activated sludge or rotating biological contactor (RBC) proved to be an effective treatment system in terms of producing an effluent characteristic within the permissible limits set by the law. Therefore, the characteristics of chemical industrial wastewater determine which treatment system to utilize. Based on laboratory results engineering design of each treatment system was developed and cost estimate prepared.  相似文献   

18.
This experimental study was conducted to evaluate a membrane sequencing batch reactor (MSBR) with mixed culture photosynthetic bacteria for dairy wastewater treatment. The study was undertaken in two steps: laboratory and pilot scale experiments. In the first step, kinetics analysis of the MSBR was carried out in a laboratory scale experiment with influent COD concentration of 2500 mg/L. The pilot scale experiment was conducted to investigate the performance of the MSBR and checked the suitability of the kinetics for an engineering design. The kinetic coefficients Ks, k, kd, Y and μm were found to be 174-mg-COD/L, 7.42/d, 0.1383/d, 0.2281/d and 1.69/d, respectively. There were some deviations of COD removal efficiency between the design value and the actual value. From the kinetics estimation, COD effluent from the design was 27 mg/L while the average actual COD effluent from the experiment was 149 mg/L. Due to the different light source condition, the factors relating to light energy (i.e. Lf and IR%) must be incorporated into engineering design and performance prediction with these kinetic coefficients of the photosynthetic MSBR.  相似文献   

19.
ABSTRACT: A stochastic programming framework is developed to evaluate the economic implications of reliability criteria and multiple effluent controls on nonpoint source pollution. An integrated watershed simulation model is used to generate probability distributions for agricultural effluents in surface and ground water resulting from agricultural practices. Results from the planning model indicate that reliability and multiple effluent constraints significantly increase the cost of nonpoint controls but the effects vary by control alternative. The analysis indicates that an evaluation of multiple water quality objectives can be an important planning tool for designing nonpoint source controls for innovative programs to promote cost-effective water quality regulation.  相似文献   

20.
Bentonites are widely used for waste repository systems because of their hydrodynamic, surface and chemical-retention properties. MX 80 bentonite (bentonite of Wyoming) contains approximately 85% Na/Ca-montmorillonite and 15% accessory minerals. The dominant presence of Na/Ca-montmorillonite in this clay mineral could cause it to perform exceptionally well as an engineered barrier for a radioactive waste repository because this buffer material is expected to fill up by swelling the void between canisters containing waste and the surrounding ground. However, the Na/Ca-montmorillonite could be transformed to other clay minerals as a function of time under repository conditions. Previous modelling studies based on the hydrolysis reactions have shown that the Na/Ca-montmorillonite-to-Ca-montmorillonite conversion is the most significant chemical transformation. In fact, this chemical process appears to be a simple cation exchange into the engineered barrier. The purpose of the present study was two-fold. Firstly, it was hoped to predict the newly formed products of bentonite-fluid reactions under repository conditions by applying a thermokinetic hydrochemical code (KIRMAT: Kinetic Reactions and Mass Transport). The system modelled herein was considered to consist of a 1-m thick zone of water-saturated engineered barrier. This non-equilibrated system was placed in contact with a geological fluid on one side, which was then allowed to diffuse into the barrier, while the other side was kept in contact with iron-charged water. Reducing initial conditions ( [P(O)2 approximately equals 0] ; Eh=-200 mV) and a constant reaction temperature (100 degrees C) were considered. Secondly, it was hoped to estimate the influence of inter-layer cations (Ca and Na) on the swelling behaviour of the MX 80 bentonite by using an isothermal system of water vapour adsorption and an environmental scanning electron microscope (ESEM) coupled with a digital image analysis (DIA) program. Here, the MX 80 bentonite was previously treated with concentrated solutions (1N) of calcium and sodium chlorides. The results confirmed that the Na/Ca-montmorillonite-to-Ca-montmorillonite conversion was the main chemical transformation in the bentonite barrier under repository conditions. A simplified method (based on volume balance) has shown that the swelling capacity of the engineered barrier would be slightly affected after 1000 years of diffusion-reaction because the volume of neo-formed swelling clays is almost directly proportional to the volume of transformed initial-montmorillonite. Minimal neo-formation of saponites, vermiculites and chlorites was also observed. In addition, an isothermal system of water adsorption and ESEM-DIA methods showed that in the raw-bentonite-to-Ca-bentonite exchange there is a small decrease in the amount of adsorbed water and the swelling potential.  相似文献   

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