Showing papers on "Wastewater published in 2010"
TL;DR: The results of this study suggest that growing algae in nutrient-rich centrate offers a new option of applying algal process in MWTP to manage the nutrient load for the aeration tank to which the centrate is returned, serving the dual roles of nutrient reduction and valuable biofuel feedstock production.
Abstract: The objective of this study was to evaluate the growth of green algae Chlorella sp. on wastewaters sampled from four different points of the treatment process flow of a local municipal wastewater treatment plant (MWTP) and how well the algal growth removed nitrogen, phosphorus, chemical oxygen demand (COD), and metal ions from the wastewaters. The four wastewaters were wastewater before primary settling (#1 wastewater), wastewater after primary settling (#2 wastewater), wastewater after activated sludge tank (#3 wastewater), and centrate (#4 wastewater), which is the wastewater generated in sludge centrifuge. The average specific growth rates in the exponential period were 0.412, 0.429, 0.343, and 0.948 day(-1) for wastewaters #1, #2, #3, and #4, respectively. The removal rates of NH4-N were 82.4%, 74.7%, and 78.3% for wastewaters #1, #2, and #4, respectively. For #3 wastewater, 62.5% of NO3-N, the major inorganic nitrogen form, was removed with 6.3-fold of NO2-N generated. From wastewaters #1, #2, and #4, 83.2%, 90.6%, and 85.6% phosphorus and 50.9%, 56.5%, and 83.0% COD were removed, respectively. Only 4.7% was removed in #3 wastewater and the COD in #3 wastewater increased slightly after algal growth, probably due to the excretion of small photosynthetic organic molecules by algae. Metal ions, especially Al, Ca, Fe, Mg, and Mn in centrate, were found to be removed very efficiently. The results of this study suggest that growing algae in nutrient-rich centrate offers a new option of applying algal process in MWTP to manage the nutrient load for the aeration tank to which the centrate is returned, serving the dual roles of nutrient reduction and valuable biofuel feedstock production.
970 citations
TL;DR: This work explores process innovations that can speed up the anammox process and use all organic matter as much as possible for energy generation.
Abstract: Organic matter must be removed from sewage to protect the quality of the water bodies that it is discharged to. Most current sewage treatment plants are aimed at removing organic matter only. They are energy-inefficient, whereas potentially the organic matter could be regarded as a source of energy. However, organic carbon is not the only pollutant in sewage: Fixed nitrogen such as ammonium (NH4+) and nitrate (NO3−) must be removed to avoid toxic algal blooms in the environment. Conventional wastewater treatment systems for nitrogen removal require a lot of energy to create aerobic conditions for bacterial nitrification, and also use organic carbon to help remove nitrate by bacterial denitrification (see the figure). An alternative approach is the use of anoxic ammonium-oxidizing (anammox) bacteria, which require less energy ( 1 ) but grow relatively slowly. We explore process innovations that can speed up the anammox process and use all organic matter as much as possible for energy generation.
968 citations
TL;DR: The first experiments using wetland macrophytes for wastewater treatment were carried out in Germany in the early 1950s and since then, the constructed wetlands have evolved into a reliable wastewater treatment technology for various types of wastewater as discussed by the authors.
Abstract: The first experiments using wetland macrophytes for wastewater treatment were carried out in Germany in the early 1950s. Since then, the constructed wetlands have evolved into a reliable wastewater treatment technology for various types of wastewater. The classification of constructed wetlands is based on: the vegetation type (emergent, submerged, floating leaved, free-floating); hydrology (free water surface and subsurface flow); and subsurface flow wetlands can be further classified according to the flow direction (vertical or horizontal). In order to achieve better treatment performance, namely for nitrogen, various types of constructed wetlands could be combined into hybrid systems.
869 citations
TL;DR: In a long term study, a total of 84 samples from seven WWTP located in the main cities along the Ebro river Basin as well as receiving river waters were analyzed to assess the occurrence of 73 pharmaceuticals covering several medicinal classes, results indicated that pharmaceuticals are widespread pollutants in the aquatic environmental.
781 citations
TL;DR: Preliminary growth studies indicated both fresh water and marine algae showed good growth in wastewaters, and further studies on anaerobic digestion and thermochemical liquefaction are required to make this consortium approach economically viable for producing algae biofuels.
756 citations
TL;DR: The study suggests that wastewater irrigation led to accumulation of heavy metals in food stuff causing potential health risks to consumers, and heavy metal contamination in the wastewater irrigated site presented a significant threat of negative impact on human health.
728 citations
TL;DR: The role of engineered nanomaterials in (pressure driven) membrane technology for water treatment, to be applied in drinking water production and wastewater recycling, is reviewed.
719 citations
TL;DR: The effectiveness of a range of processes including tertiary media filtration, ozonation, chlorination, UV irradiation, activated carbon adsorption, and NF/RO filTration has been reviewed and semi-quantitative estimations of antibiotics removals have been provided.
668 citations
TL;DR: The present review attempts to link various compartmentalization aspects of the nanoparticles, their physical properties and toxicity in wastewater and wastewater sludge through simile drawn from other environmental streams.
615 citations
TL;DR: In this paper, a combination of source control, and farm-level and post-harvest measures can be used to protect farm workers and consumers from adverse impacts from wastewater irrigation in developing countries.
609 citations
TL;DR: Protein and lipids content analysis suggest that, from a practical point of view, immobilized systems could facilitate the separation of the biomass from the treated wastewater although in terms of nutritional value of the microalgae, immobilization systems do not represent an advantage over free-cell systems.
TL;DR: This field-scale study provides for the first time nanoparticle-level information of the Ag(2)S present in sewage sludge products, and further suggests the role of wastewater treatment processes on transformation of Ag nanoparticles and ionic Ag potentially released from them.
Abstract: Nanosized silver sulfide (α-Ag2S) particles were identified in the final stage sewage sludge materials of a full-scale municipal wastewater treatment plant using analytical high-resolution transmission electron microscopy. The Ag2S nanocrystals are in the size range of 5−20 nm with ellipsoidal shape, and they form very small, loosely packed aggregates. Some of the Ag2S nanoparticles (NPs) have excess S on the surface of the sulfide minerals under S-rich environments, resulting in a ratio of Ag to S close to 1. Considering the current extensive production of Ag NPs and their widespread use in consumer products, it is likely that they are entering wastewater streams and the treatment facilities that process this water. This study suggests that in a reduced, S-rich environment, such as the sedimentation processes during wastewater treatment, nanosized silver sulfides are being formed. This field-scale study provides for the first time nanoparticle-level information of the Ag2S present in sewage sludge produc...
TL;DR: In this article, the authors reviewed the fundamentals of agricultural irrigation using treated municipal wastewater and the status of municipal wastewater reuse in Greece and Spain with studies related to the effects on soils and plants.
01 Dec 2010
TL;DR: In this article, the importance of Electrode Material in the Electrochemical Treatment of Wastewater Containing Organic Pollutants for Wastewater Treatment has been discussed, including the use of both anode and cathode reactions in wastewater treatment.
Abstract: Basic Principles of the Electrochemical Mineralization of Organic Pollutants for Wastewater Treatment.- Importance of Electrode Material in the Electrochemical Treatment of Wastewater Containing Organic Pollutants.- Techniques of Electrode Fabrication.- Modeling of Electrochemical Process for the Treatment of Wastewater Containing Organic Pollutants.- Green Electroorganic Synthesis Using BDD Electrodes.- Domestic and Industrial Water Disinfection Using Boron-Doped Diamond Electrodes.- Drinking Water Disinfection by In-line Electrolysis: Product and Inorganic By-Product Formation.- Case Studies in the Electrochemical Treatment of Wastewater Containing Organic Pollutants Using BDD.- The Persulfate Process for the Mediated Oxidation of Organic Pollutants.- Electrocoagulation in Water Treatment.- Electroflotation.- Electroreduction of Halogenated Organic Compounds.- Principles and Applications of Solid Polymer Electrolyte Reactors for Electrochemical Hydrodehalogenation of Organic Pollutants.- Preparation, Analysis and Behaviors of Ti-Based SnO2 Electrode and the Function of Rare-Earth Doping in Aqueous Wastes Treatment.- Wet Electrolytic Oxidation of Organics and Application for Sludge Treatment.- Environmental Photo(electro)catalysis: Fundamental Principles and Applied Catalysts.- Solar Disinfection of Water by TiO2 Photoassisted Processes: Physicochemical, Biological, and Engineering Aspects.- Fabrication of Photoelectrode Materials.- Use of Both Anode and Cathode Reactions in Wastewater Treatment.
TL;DR: A review of plant-based coagulant sources, processes, effectiveness and relevant coagulating mechanisms for treatment of water and wastewater is presented in this article, where nirmali seeds (Strychnos potatorum), Moringa oleifera, tannin and cactus.
TL;DR: The ozonation and microfiltration/reverse osmosis processes employed in two WWTPs were very effective to remove them, showing their main contributions to the removal of such micro-pollutants in wastewater treatment.
TL;DR: In this sense, advanced oxidation processes are possibly one of the most effective methods for the treatment of wastewater containing organic products (effluents from chemical and agrochemical industries, the textile industry, paints, dyes, etc.).
Abstract: The protection and conservation of natural resources is one of the main priorities of modern society. Water is perhaps our most valuable resource, and thus should be recycled. Many of the current recycling techniques for polluted water only concentrate the pollutant without degrading it or eliminating it. In this sense, advanced oxidation processes are possibly one of the most effective methods for the treatment of wastewater containing organic products (effluents from chemical and agrochemical industries, the textile industry, paints, dyes, etc.). More conventional techniques cannot be used to treat such compounds because of their high chemical stability and/or low biodegradability. This article describes, classifies, and analyzes different types of advanced oxidation processes and their application to the treatment of polluted wastewater.
TL;DR: The results demonstrate that the main advantages of using temperature-phased, in-series MFC configurations for domestic wastewater treatment are power savings, low solids production, and higher treatment efficiency.
TL;DR: Overall, the sewer system appears to be a defined environment with both infiltration of rainwater and stormwater inputs modulating community composition, and microbial sewage communities represent a combination of inputs from human faecal microbes and enrichment of specific microbes from the environment to form a unique population structure.
Abstract: The release of untreated sewage introduces non-indigenous microbial populations of uncertain composition into surface waters. We used massively parallel 454 pyrosequencing of hypervariable regions in rRNA genes to profile microbial communities from eight untreated sewage influent samples of two wastewater treatment plants (WWTPs) in metropolitan Milwaukee. The sewage profiles included a discernible human faecal signature made up of several taxonomic groups including multiple Bifidobacteriaceae, Coriobacteriaceae, Bacteroidaceae, Lachnospiraceae and Ruminococcaceae genera. The faecal signature made up a small fraction of the taxa present in sewage but the relative abundance of these sequence tags mirrored the population structures of human faecal samples. These genera were much more prevalent in the sewage influent than standard indicators species. High-abundance sequences from taxonomic groups within the Beta- and Gammaproteobacteria dominated the sewage samples but occurred at very low levels in faecal and surface water samples, suggesting that these organisms proliferate within the sewer system. Samples from Jones Island (JI--servicing residential plus a combined sewer system) and South Shore (SS--servicing a residential area) WWTPs had very consistent community profiles, with greater similarity between WWTPs on a given collection day than the same plant collected on different days. Rainfall increased influent flows at SS and JI WWTPs, and this corresponded to greater diversity in the community at both plants. Overall, the sewer system appears to be a defined environment with both infiltration of rainwater and stormwater inputs modulating community composition. Microbial sewage communities represent a combination of inputs from human faecal microbes and enrichment of specific microbes from the environment to form a unique population structure.
TL;DR: Data from two different harvests suggest that the uptake from soil to root and translocation from root to leaf may be rate limited for triclosan and triclocarban and metabolism may occur within the plant for carbamazepine.
Abstract: Many pharmaceuticals and personal care products (PPCPs) are commonly found in biosolids and effluents from wastewater treatment plants. Land application of these biosolids and the reclamation of treated wastewater can transfer those PPCPs into the terrestrial and aquatic environments, giving rise to potential accumulation in plants. In this work, a greenhouse experiment was used to study the uptake of three pharmaceuticals (carbamazepine, diphenhydramine, and fluoxetine) and two personal care products (triclosan and triclocarban) by an agriculturally important species, soybean (Glycine max (L.) Merr.). Two treatments simulating biosolids application and wastewater irrigation were investigated. After growing for 60 and 110 days, plant tissues and soils were analyzed for target compounds. Carbamazepine, triclosan, and triclocarban were found to be concentrated in root tissues and translocated into above ground parts including beans, whereas accumulation and translocation for diphenhydramine and fluoxetine w...
TL;DR: N(2)O formation was shown to be always positive, yet highly variable across the seven full-scale BNR wastewater treatment plants (WWTP), but with many competing and parallel nitrogen transformation reactions occurring, it was very difficult to clearly identify the predominant mechanism of N( 2)O production.
TL;DR: Future challenges and frontiers in wastewater management posed by PPCPs are addressed including analytical needs for their real-time measurement, energy demands associated with advanced treatment technologies, and byproducts arising from transformation of PPCP during treatment.
Abstract: Pharmaceuticals and personal care products (PPCPs) represent pollutants of emerging concern, originating in surface and drinking waters largely from their persistence in wastewater effluent. Accordingly, a wealth of recent investigations has examined PPCP fate during wastewater treatment, focusing on their removal during conventional (e.g., activated sludge) and advanced (e.g., ozonation and membrane filtration) treatment processes. Here, we compile nearly 1500 data points from over 40 published sources pertaining to influent and effluent PPCP concentrations measured at pilot- and full-scale wastewater treatment facilities to identify the most effective series of technologies for minimizing effluent PPCP levels. Available data suggest that at best a 1-log10 concentration unit (90%) of PPCP removal can be achieved at plants employing only primary and secondary treatment, a performance trend that is maintained over the range of reported PPCP influent concentrations (ca. 0.1–105 ng L−1). Relatively few compounds (15 of 140 PPCPs considered) are consistently removed beyond this threshold at facilities using solids removal and conventional activated sludge (CAS), and most PPCPs are removed to a far lesser extent. Further, increases in CAS hydraulic retention time or sludge retention time do not appreciably increase removal beyond this limit. In contrast, plants employing advanced treatment methodologies, particularly ozonation and/or membranes, remove the vast majority of PPCPs beyond 1-log10 concentration unit and oftentimes to levels below analytical detection limits in effluent. Data also indicate that passive approaches for tertiary treatment (e.g., wetlands and lagoons) represent promising options for PPCP removal. We conclude by addressing future challenges and frontiers in wastewater management posed by PPCPs including analytical needs for their real-time measurement, energy demands associated with advanced treatment technologies, and byproducts arising from transformation of PPCPs during treatment.
TL;DR: The study demonstrates that sampling uncertainty can range from "not significant" to "far greater than the uncertainty due to chemical analysis", which is site- and compound-specific and depends on the (in)accuracy of the analytical method.
Abstract: The aim of this study was to assess uncertainties associated with different sampling modes when evaluating loads of pharmaceuticals and personal care products (PPCPs) in sewers and influents to sewage treatment plants (STPs). The study demonstrates that sampling uncertainty can range from “not significant” to “far greater than the uncertainty due to chemical analysis”, which is site- and compound-specific and depends on the (in)accuracy of the analytical method. Conventional sampling devices operated in common time- or flow-proportional sampling modes, and applying traditional sampling intervals of 30 min or longer can result in the collection of nonrepresentative samples. At the influent of a STP, wastewater may appear as a continuous stream, but it is actually composed of a number of intermittently discharged, individual wastewater packets from household appliances, industries, or subcatchments in pressurized sewer systems. The resulting heterogeneity can cause significant short-term variations of pollu...
TL;DR: Surfactants in the Environment Surfactants are a diverse group of chemicals that are best known for their wide use in detergents and other cleaning products and most of them end up dispersed in different environmental compartments such as soil, water or sediment.
Abstract: Surfactants are a diverse group of chemicals that are best known for their wide use in detergents and other cleaning products. After use, residual surfactants are discharged into sewage systems or directly into surface waters, and most of them end up dispersed in different environmental compartments such as soil, water or sediment. The toxic effects of surfactants on various aquatic organisms are well known. In general, surfactants are present in the environment at levels below toxicity and in Croatia below the national limit. Most surfactants are readily biodegradable and their amount is greatly reduced with secondary treatment in wastewater treatment plants. The highest concern is the release of untreated wastewater or wastewater that has undergone primary treatment alone. The discharge of wastewater polluted with massive quantities of surfactants could have serious effects on the ecosystem. Future studies of surfactant toxicities and biodegradation are necessary to withdraw highly toxic and non-biodegradable compounds from commercial use and replace them with more environmentally friendly ones.
TL;DR: Toxicity tests with Vibrio fisheri showed that degradation of the compounds in real effluent wastewater led to toxicity increase, but is relatively independent of pH, the type of acid used for release of hydroxyl radicals scavengers and the initial H(2)O( 2) concentration used.
TL;DR: The research which might accelerate the progress towards sustainable wastewater treatment using MFCs is reviewed: system control and modelling and the understanding of the ecology of the microbial communities that catalyse the generation of electricity are reviewed.
TL;DR: Assessment of the removal of organic micropollutants and the concurrent reduction of their biological activity in a full scale reclamation plant treating secondary effluent found that the main ozonation formed oxidation by-products but decreased the level of non-specific toxicity and other specific toxic modes of action.
TL;DR: In this article, the quest to find an economically viable substitute to active carbon adsorbent to remove toxic metal ions was described, and a brief discussion of design of batch and column adsorption experiments, development of inexpensive adsorbents, and experimental conditions of metal ions removal by batch or column procedures is included.
Abstract: Due to overgrowth in population, industrialization and civilization, demands for water are increasing geometrically. Therefore, alternative sources of water are required and wastewater treatment and recycling may serve this purpose. Among various water treatment technologies, adsorption onto activated carbon is in the front line due to its universal nature. Activated carbon is the best adsorbent able to capture inorganic, as well as organic, pollutants that contaminate water resources. Inorganic pollutants, especially metal ions, are more dangerous due to their toxic and possibly carcinogenic natures. Also they are most often persistent and difficult to biodegrade. The present article describes the quest to find an economically viable substitute to active carbon adsorbent to remove toxic metal ions. A brief discussion of design of batch and column adsorption experiments, development of inexpensive adsorbents, and experimental conditions of metal ions removal by batch and column procedures is included. Eff...
TL;DR: This research shows that the wastewater treatment HRAPs with CO(2) addition achieved a mean algal productivity of 16.7 g/m(2)/d, which is higher than the maximum algae productivity for the HRAP(4d) (4 d HRT), and higher bacterial composition and the larger size of algal/bacterial flocs of theHRAP(8d) biomass increased harvestability.
TL;DR: In this article, the ozone-based advanced oxidation processes (O3, O3/UV and O 3/UV/H2O2) on the treatment of winery wastewater were investigated in a pilot-scale bubble column reactor.