Showing papers on "Wastewater published in 2002"
1,798 citations
TL;DR: The aqueous solubility data for the APE metabolites indicate that the concentration in water combined with the high partition coefficients will provide a significant reservoir (load) in various environmental compartments and indicate that they will partition effectively into sediments following discharge from STPs.
1,039 citations
TL;DR: Very high concentrations of BPA and phthalates were confirmed in waste dump water and compost water samples as well as in the liquid manure samples.
920 citations
TL;DR: In this article, the removal of poisonous Cr(VI) from industrial wastewater by different low-cost abundant adsorbents was investigated, including wool, olive cake, sawdust, pine needles, almond shells, cactus leaves and charcoal were used at different adsorbent/metal ion ratios.
884 citations
TL;DR: In this article, the authors identified 900 different XOCs potentially present in grey wastewater by the use of tables of contents of household chemical products and found that the levels of heavy metals are in the same concentration range.
839 citations
TL;DR: The measured vertical concentration profile of triclosan in a lake sediment core of lake Greifensee reflects its increased use over 30 years, and the measured concentrations in surface waters are in the range of the predicted no effect concentration of 50 ng/L.
Abstract: Triclosan is used as an antimicrobial agent in a wide range of medical and consumer care products. To investigate the occurrence and fate of triclosan in the aquatic environment, analytical methods for the quantification of triclosan in surface water and wastewater, sludge, and sediment were developed. Furthermore, the fate of triclosan in a wastewater treatment plant (biological degradation, 79%; sorption to sludge, 15%; input into the receiving surface water, 6%) was measured during a field study. Despite the high overall removal rate, the concentration in the wastewater effluents were in the range of 42−213 ng/L leading to concentrations of 11−98 ng/L in the receiving rivers. Moreover, a high removal rate of 0.03 d-1 for triclosan in the epilimnion of the lake Greifensee was observed. This is due to photochemical degradation. The measured vertical concentration profile of triclosan in a lake sediment core of lake Greifensee reflects its increased use over 30 years. As the measured concentrations in sur...
763 citations
TL;DR: The risk quotients obtained suggest a low probability for adverse effects of the occurring FQs, either on microbial activity in WWTPs or on algae, daphnia, and fish in surface waters, following the recommendations of the European guidelines or draft documents.
Abstract: The mass flows of fluoroquinolone antibacterial agents (FQs) were investigated in the aqueous compartments of the Glatt Valley Watershed, a densely populated region in Switzerland. The major human-use FQs consumed in Switzerland, ciprofloxacin (CIP) and norfloxacin (NOR), were determined in municipal wastewater effluents and in the receiving surface water, the Glatt River. Individual concentrations in raw sewage and in final wastewater effluents ranged from 255 to 568 ng/L and from 36 to 106 ng/L, respectively. In the Glatt River, the FQs were present at concentrations below 19 ng/L. The removal of FQs from the water stream during wastewater treatment was between 79 and 87%. During the studied summer period, FQs in the dissolved fraction were significantly reduced downstream in the Glatt River (15-20 h residence time) (66% for CIP and 48% for NOR). Thus, after wastewater treatment, transport in rivers causes an additional decrease of residual levels of FQs in the aquatic environment. Refined predicted environmental concentrations for the study area compare favorably with the measured environmental concentrations (MEC) obtained in the monitoring study. Total measured FQ concentrations occurring in the examined aquatic compartments of the Glatt Valley Watershed were related to acute ecotoxicity data from the literature. The risk quotients obtained (MEC/PNEC < 1) following the recommendations of the European guidelines or draft documents suggest a low probability for adverse effects of the occurring FQs, either on microbial activity in WWTPs or on algae, daphnia, and fish in surface waters.
482 citations
TL;DR: The combination of partial nitritation to produce nitrite in a first step and subsequent anaerobic ammonium oxidation in a second reactor was successfully tested on a pilot scale and limited the overall maximum rate of nitrogen elimination.
462 citations
TL;DR: Investigation of the fate and removal of triclosan (TCS), an antimicrobial agent used in a variety of household and personal-care products, in wastewater treatment systems suggests that TCS is readily biodegradable under aerobic conditions, but not under anaerobic conditions.
Abstract: The objective of this study was to investigate the fate and removal of triclosan (TCS; 5-chloro-2-[2,4-dichloro-phenoxy]-phenol), an antimicrobial agent used in a variety of household and personal-care products, in wastewater treatment systems. This objective was accomplished by monitoring the environmental concentrations of TCS, higher chlorinated derivatives of TCS (4,5-dichloro-2-[2,4-dichloro-phenoxy]-phenol [tetra II]; 5,6-dichloro-2-[2,4-dichloro-phenoxy]-phenol [tetra III]; and 4,5,6-trichloro-2-(2,4-dichloro-phenoxy)-phenol [penta]), and a potential biotransformation by-product of TCS (5-chloro-2-[2,4-dicholoro-phenoxy]-anisole [TCS-OMe]) during wastewater treatment. These analytes were isolated from wastewater by using a C18 solid-phase extraction column and from sludge with supercritical fluid CO2. Once the analytes were isolated, they were derivatized to form trimethylsilylethers before quantitation by gas chromatography-mass spectrometry. Recovery of TCS from laboratory-spiked wastewater samples ranged from 79 to 88% for influent, 36 to 87% for final effluent, and 70 to 109% for primary sludge. Field concentrations of TCS in influent wastewater ranged from 3.8 to 16.6 microg/L and concentrations for final effluent ranged from 0.2 to 2.7 microg/L. Removal of TCS by activated-sludge treatment was approximately 96%, whereas removal by trickling-filter treatment ranged from 58 to 86%. The higher chlorinated tetra-II, tetra-III, and penta closans were below quantitation in all of the final effluent samples, except for one sampling event. Digested sludge concentrations of TCS ranged from 0.5 to 15.6 microg/g (dry wt), where the lowest value was from an aerobic digestion process and the highest value was from an anaerobic digestion process. Analysis of these results suggests that TCS is readily biodegradable under aerobic conditions, but not under anaerobic conditions. The higher chlorinated closans were near or below the limit of quantitation in all of the digested sludge samples. Based on results from this study, the chlorinated analogues and biotransformation by-product of TCS are expected to be very low in receiving waters and sludge-amended soils.
450 citations
TL;DR: The sources of sewage water from households are still poorly understood or that known sources are underestimated, and in the case of stormwater, the estimated contributions are rather well in agreement with measured contributions, although uncertainties are large for both estimations and measurements.
447 citations
TL;DR: In this paper, a 3.0-l upflow reactor was used to investigate individual effects of hydraulic retention time (HRT), chemical oxygen demand (COD) concentration in wastewater (14- 36 g COD/l), pH (4.5-6.0), and temperature (20-55°C) on bio-hydrogen production from the wastewater.
TL;DR: The first full-scale constructed wetland (CW) for wastewater treatment was built in the Czech Republic in 1989 and by the end of 1999, about 100 CWs were put into operation as mentioned in this paper.
TL;DR: In this paper, the use of low-cost adsorbent has been investigated as a replacement for the current expensive methods of removing dyes from wastewater for fly ash generated in National Thermal Power plant.
Abstract: The use of low-cost adsorbent has been investigated as a replacement for the current expensive methods of removing dyes from wastewater. As such, fly ash generated in National Thermal Power plant w...
TL;DR: The pilot-scale wastewater treatment system consisting of a free water surface (FWS) and a subsurface flow (SSF) constructed wetlands arranged in series was operated for around 8 months to examine system start-up phenomena and evaluate system performance in removing inorganic nitrogen and phosphate from aquaculture wastewater under various hydraulic loading rates.
TL;DR: The studies showed that the palm seed coat carbon can be used as an efficient adsorbent material for the removal of phenolics from water and wastewater.
TL;DR: Effect of dyes and salts present in textile wastewater on methanogenesis was evaluated based on maximum methane production and methanogenic activity and it was observed that the black dye concentration of 400 mg/l seemed to cause inhibition of meethanogenesis.
TL;DR: It was demonstrated that only with an efficient filtration step one can meet stringent standards such as the California Title 22 criteria, and the standard drinking water model failed to match the experimental data obtained on real wastewater effluents.
TL;DR: The germination index indicated the reduction of phytotoxicity during composting and the use of maize straw or cotton waste as bulking agents in the composting of olive mill wastewater sludge was compared.
TL;DR: The feasibility of combining microalgae and macrophytes for bioremediation of recalcitrant industrial wastewater is demonstrated, and L. minuscule was able to grow in the treated wastewater, precipitated the microalgal cells, and reduced other organic matter and color after an additional 6 days of incubation.
TL;DR: This study demonstrated that the pre-treated biomass of Padina sp.
TL;DR: Five rapid direct toxicity assessment methods were used in three European partner countries to determine the toxicity of single toxicants, mixed toxicants and real industrial wastes to protect microbial degradation of organic wastes in biological treatment processes and hence enhance the quality of treated effluents to be discharged to the environment.
TL;DR: In this paper, the performance of an integrated activated sludge bioreactor-membrane microfiltration system was investigated, and the results reveal that the smaller particles played a more important role in membrane fouling.
TL;DR: In this article, the authors present the investigations carried out by numerous researchers on the use of different kinds of adsorbents and their adsorption capacities for the removal of specific dyes from textile wastewater.
Abstract: Textile wastewater presents a challenge to conventional physico-chemical and biological treatment methods. Liquid-phase adsorption has been shown to be highly efficient for the removal of dyes and other organic matters from process or waste effluent. Many different types of adsorbent are used to remove colour from wastewater among which the most widely used material is activated carbon. Since activated carbon is expensive and necessitates regeneration, attempts have been made to substitute alternatives that are biodegradable, low cost and/or waste materials. This article presents the investigations carried out by numerous researchers on the use of different kinds of adsorbents and their adsorption capacities for the removal of specific dyes from textile wastewater.
TL;DR: In this article, the potential of Arundo donax stems, Brazil nutshells, sugarcane bagasse, and sawdust from a native wood species (Prosopis ruscifolia) to sequester trace metals from wastewater was comparatively examined using dilute aqueous solutions of Cd(II)/Ni(II) ions as models.
Abstract: The potential capability of Arundo donax stems, Brazil nutshells, sugarcane bagasse, and sawdust from a native wood species (Prosopis ruscifolia) to sequester trace metals from wastewater was comparatively examined using dilute aqueous solutions of Cd(II) or Ni(II) ions as models. Brazil nutshells showed the best effectiveness (>90%) for the uptake of both metals from solutions of 20 mg/L initial concentration for dosages larger than 0.2−0.4 mg/L, even superior to those obtained for a commercial activated carbon and/or red marine algae (Corallinales) used for comparison under identical conditions. Equilibrium isotherms of cadmium on the lignocellulosic and algae samples and of nickel on the nutshells were determined and properly described by the Langmuir model. The highest maximum sorption capacity of Cd(II) ions was obtained for the nutshells (Xm = 19.4 mg/g) among the lignocellulosic samples. The trend in the estimated Xm values was found to be consistent with their contents of lignin and total surface ...
Book•
29 Jul 2002TL;DR: In this article, the authors present a survey of the characteristics of water and wastewater in the United States, including the following: 1) Water and Wastewater Physical-Chemical Treatment of Water and Wastewater Unit Operations and Unit Processes Coverage Clean Water Act Safe Drinking Water Act Relationship of This Book to the Acts Glossary Background Chemistry and Fluid Mechanics Units Used in Calculation General Chemistry Fluid mechanics Glossary Problems Bibliography PART I: CHARACTERISTICS of WATER and WASTEWATER QUANTITY OF WATER AND WASTewATER Probability
Abstract: BACKGROUND PREREQUISITES Introduction Wastewater Physical-Chemical Treatment of Water and Wastewater Unit Operations and Unit Processes Coverage Clean Water Act Safe Drinking Water Act Relationship of This Book to the Acts Glossary Background Chemistry and Fluid Mechanics Units Used in Calculation General Chemistry Fluid Mechanics Glossary Problems Bibliography PART I: CHARACTERISTICS OF WATER AND WASTEWATER QUANTITY OF WATER AND WASTEWATER Probability Distribution Analysis Quantity of Water Types of Wastewater Sources and Quantities of Wastewater Population Projection Derivation of Design Flows of Wastewaters Deriving Design Flows of Wastewaters from Field Survey CONSTITUENTS OF WATER AND WASTEWATER Physical and Chemical Characteristics Normal Constituents of Domestic Wastewater Microbiological Characteristics PART II: UNIT OPERATIONS OF WATER AND WASTEWATER TREATMENT FLOW MEASUREMENTS AND FLOW AND QUALITY EQUALIZATIONS Flow Meters Miscellaneous Flow Meters Liquid Level Indicators Flow and Quality Equalizations PUMPING Pumping Stations and Types of Pumps Pumping Station Heads Pump Characteristics and Best Operating Efficiency Pump Scaling Laws Pump Specific Speed Net Positive Suction Head and Deep-Well Pumps Pumping Station Head Analysis SCREENING, SETTLING, AND FLOTATION Screening Settling Flotation MIXING AND FLOCCULATION Rotational Mixers Criteria for Effective Mixing Pneumatic Mixers Hydraulic Mixers Flocculators CONVENTIONAL FILTRATION Types of Filters Medium Specification for Granular Filters Linear Momentum Equation Applied to Filters Head Losses in Grain Filters Backwashing Head Loss in Granular Filters Cake Filtration ADVANCED FILTRATION AND CARBON ADSORPTION Electrodialysis Membranes Pressure Membranes Carbon Adsorption AERATION, ABSORPTION, AND STRIPPING Mass Transfer Units Interface for Mass Transfer, and Gas and Liquid Boundary Layers Mathematics of Mass Transfer Dimensions of the Overall Mass Transfer Coefficients Mechanics of Aeration Absorption and Stripping PART III: UNIT PROCESSES OF WATER AND WASTEWATER TREATMENT WATER SOFTENING Hard Waters Types of Hardness Plant Types for Hardness Removal The Equivalent CaCO(3) Concentration Softening of Calcium Hardness Softening of Magnesium Hardness Lime-Soda Process Order of Removal Role of CO(2) in Removal Excess Lime Treatment and Optimum Operational pH Summary of Chemical Requirements and Solids Produced Sludge Volume Production Chemical Species in the Treated Water Relationships of the Fractional Removals Notes on Equivalent Masses Typical Design Parameters and Criteria Split Treatment Use of Alkalinity in Water Softening Calculations WATER STABILIZATION Carbonate Equilibria Criteria for Water Stability at Normal Conditions Recarbonation of Softened Water COAGULATION Colloid Behavior Zeta Potential Colloid Destabilization Coagulation Process Chemical Reactions of Alum Chemical Reactions of the Ferrous Ion Chemical Reactions of the Ferric Ion Jar Tests for Optimum pH Determination Chemical Requirements Chemical Requirements for pH Adjustments Alkalinity and Acidity Expressed as CaCO(3) Sludge Production REMOVAL OF IRON AND MANGANESE BY CHEMICAL PRECIPITATION Natural Occurrences of Iron and Manganese Modes of Removal of Iron and Manganese Chemical Reactions of the Ferrous and the Ferric Ions Chemical Reactions of the Manganous Ion [Mn(II)] Oxidation of Iron and Manganese Unit Operations for Iron and Manganese Removal Chemical Requirements Alkalinity Expressed in OH(-) and Acidity Expressed in H(+) Chemical Requirements for pH Adjustments Sludge Production REMOVAL OF PHOSPHORUS BY CHEMICAL PRECIPITATION Natural Occurrence of Phosphorus Modes of Phosphorus Removal Chemical Reaction of the Phosphate Ion with Alum Chemical Reaction of the Phosphate Ion with Lime Chemical Reaction of the Phosphate Ion with the Ferric Salts Comments on the Optimum pH Ranges Effect of the K(sp)'s on the Precipitation of Phosphorus Unit Operations for Phosphorus Removal Chemical Requirements Sludge Production REMOVAL OF NITROGEN BY NITRIFICATION-DENITRIFICATION Natural Occurrence of Nitrogen To Remove or Not to Remove Nitrogen Microbial Thermodynamics Oxidation-Reduction Reactions of Nitrogen Foods Modes of Nitrogen Removal Chemical Reactions in Nitrogen Removal Total Effluent Nitrogen Carbon Requirements for Denitrification Alkalinity Production and Associated Carbon Requirement Reaction Kinetics ION EXCHANGE Ion Exchange Reactions Unit Operations of Ion Exchange Sodium, Hydrogen Cycle, and Regeneration Production of "Pure Water" Active or Exchange Zone Design of Ion Exchangers Head Losses in Ion Exchangers DISINFECTION Methods of Disinfection and Disinfectant Agents Used Factors Affecting Disinfection Other Disinfection Formulas Chlorine Disinfectants Dechlorination Disinfection Using Ozone Disinfection Using Ultraviolet Light APPENDICES INDEX Each chapter contains: Glossary, Symbols, Problems and Bibliography
TL;DR: The results indicate that functionally stable wastewater treatment bioreactors have stable microbial community structures under normal operating conditions but are able to adapt in response to perturbations to sustain high effluent quality.
TL;DR: The equilibrium adsorption capacity of rubber seed coat activated carbon for phenol removal was obtained by using linear Freundlich isotherm and the suitability of RSCC for treating phenol based resin manufacturing industry wastewater was tested.
TL;DR: Results obtained by gas chromatography analyses and toxicity tests with Artemia salina showed that a significant improvement in the effluent's quality was achieved after treatment by the combined (microfiltration/biological) process.
TL;DR: In this article, photo-degradation and biodegradability have been studied for three different families of non-biodegradable textile dyes (Intracron reactive dyes, Direct dyes and Nylanthrene acid dyes) using VUV photolysis.
Abstract: Photo-degradation and biodegradability have been studied for three different families of non-biodegradable textile dyes (Intracron reactive dyes, Direct dyes and Nylanthrene acid dyes) and a textile wastewater, using VUV photolysis. Ninety percent of color removal of dye solutions and wastewater is achieved within 7 min of irradiation. Biological oxygen demand (BOD) was found to increase during discoloration process while chemical oxygen demand (COD) decreased. The biodegradability index (BOD5/COD) increases up to 0.40 for most of the dye solutions when total discoloration is obtained. It implies that VUV photolysis tends to enhance the biodegradability of dye containing solutions. Thus, this technique could be used as a pre-treatment step for conventional biological wastewater treatment.
TL;DR: In this article, a novel approach in the treatment of olive mill wastewater is presented, based on a preliminary rheological characterization of the waste and on the evaluation of permeation efficiency that was analyzed as a function of several parameters such as the importance of pre-treating wastewater, the effects of localized turbulence, promoted by UF module geometry, and of the main operating variables (transmembrane pressure and feed flow rate).