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Effect of transpiration on plant accumulation and translocation of PPCP/EDCs
2015
Dodgen, Laurel K. | Ueda, Aiko | Wu, Xiaoqin | Parker, David R. | Gan, Jay
The reuse of treated wastewater for agricultural irrigation in arid and hot climates where plant transpiration is high may affect plant accumulation of pharmaceutical and personal care products (PPCPs) and endocrine disrupting chemicals (EDCs). In this study, carrot, lettuce, and tomato plants were grown in solution containing 16 PPCP/EDCs in either a cool-humid or a warm-dry environment. Leaf bioconcentration factors (BCF) were positively correlated with transpiration for chemical groups of different ionized states (p < 0.05). However, root BCFs were correlated with transpiration only for neutral PPCP/EDCs (p < 0.05). Neutral and cationic PPCP/EDCs showed similar accumulation, while anionic PPCP/EDCs had significantly higher accumulation in roots and significantly lower accumulation in leaves (p < 0.05). Results show that plant transpiration may play a significant role in the uptake and translocation of PPCP/EDCs, which may have a pronounced effect in arid and hot climates where irrigation with treated wastewater is common.
Show more [+] Less [-]Advanced Oxidation Processes (AOPs) in Wastewater Treatment
2015
Deng, Yang | Zhao, Renzun
Advanced oxidation processes (AOPs) were first proposed in the 1980s for drinking water treatment and later were widely studied for treatment of different wastewaters. During the AOP treatment of wastewater, hydroxyl radicals (OH·) or sulfate radicals (SO₄ ·⁻) are generated in sufficient quantity to remove refractory organic matters, traceable organic contaminants, or certain inorganic pollutants, or to increase wastewater biodegradability as a pre-treatment prior to an ensuing biological treatment. In this paper, we review the fundamental mechanisms of radical generation in different AOPs and select landfill leachate and biologically treated municipal wastewater as model wastewaters to discuss wastewater treatment with different AOPs. Generally, the treatment efficiencies rely heavily upon the selected AOP type, physical and chemical properties of target pollutants, and operating conditions. It would be noted that other mechanisms, besides hydroxyl radical or sulfate radical-based oxidation, may occur during the AOP treatment and contribute to the reduction of target pollutants. Particularly, we summarize recent advances in the AOP treatment of landfill leachate, as well as advanced oxidation of effluent organic matters (EfOM) in biologically treated secondary effluent (BTSE) for water reuse.
Show more [+] Less [-]Use of Bamboo Powder Waste for Removal of Bisphenol A in Aqueous Solution
2015
Hartono, Maria R. | Assaf, Ali | Thouand, Gérald | Kushmaro, Ariel | Chen, Xiaodong | Marks, Robert S.
The scarcity of clean water affecting many parts of the world encourages efforts to improve water reclamation processes, which rely on their capability to remove diverse types of water pollutants and contaminants. Thus, this study reports the application of bamboo fiber powders as potential low-cost sorbent for removal of noxious organic compounds in aqueous solution. Bisphenol A, a biorefractory endocrine disruptor compound, was chosen as model compound in order to easily follow the separation process. Principal component analysis of the FTIR spectra and BET surface area measurements were performed on treated bamboo fiber powders. Treatment of the raw powders with alkali, ionic and non-ionic surfactants appeared to improve the bisphenol A removal performance of the bamboo fiber powders with the best removal efficiency reached at 39 % for a sorbent dosage of 4 g L⁻¹ gained after a bamboo treatment using the cationic surfactant. Effects of contact time, sorbent dosage, and particle sizes (55, 300, and 1000 μm) of cationic surfactant-treated bamboo fiber powders towards removal of bisphenol A were further assessed in a batch system with an optimum removal observed for 55 μm in particle size.
Show more [+] Less [-]Pathogen Inactivation and the Chemical Removal of Phosphorus from Swine Wastewater
2015
Viancelli, A. | Kunz, A. | Fongaro, G. | Kich, J. D. | Barardi, C. R. M. | Suzin, L.
Inactivation of pathogens present in animal manure prior to land application has justified the use of advanced technologies. However, some alternatives are expensive or not effective due to the organic material and suspended solids present in the effluent (e.g., ozone, UV light). The use of hydrated lime (calcium hydroxide, Ca(OH)₂) is an attractive wastewater treatment option due to the ability of lime to kill pathogens and to extract phosphorus from manure at an alkaline pH. The present study aimed to evaluate the soluble phosphorus removal and pathogen inactivation (Escherichia coli, Salmonella enterica serovar typhymurium and Porcine circovirus type 2), in the liquid fraction and in the solid generated after Ca(OH)₂ addition in swine wastewater, exposed for 3 and 24 h at different pH conditions: 9.0, 9.5, and 10.0. The results showed the efficiency of pH elevation with Ca(OH)₂ in the removal of soluble P at pH 9.0 and the total inactivation of E. coli, Salmonella, and P. circovirus type 2 at pH 10.0. The liquid fraction (reuse water) could be safely used for cleaning the swine production facilities, and the solid fraction (precipitated P) could be used as a secondary product and fertilizer.
Show more [+] Less [-]Alkylphenols and Phthalates in Greywater from Showers and Washing Machines
2015
Deshayes, Steven | Eudes, Véronique | Droguet, Christine | Bigourie, Magali | Gasperi, Johnny | Moilleron, Régis
Paris conurbation is a heavily urbanized but weakly industrialized catchment. Recently, it has been shown at the scale of Paris that alkylphenols (AP) and phthalates (PAE) are not rejected by the industry, but they originate from domestic wastewater at more than 95 %. However, the contribution of the different types of greywater to the pollution by alkylphenols and phthalates was not addressed. This work aims at providing new insights on this particular point. Hence, the concentration of four phthalates (diethyl phthalate (DEP), di-n-butyl phthalate (DnBP), benzyl butyl phthalate (BBP), and di(2-ethylhexyl)phthalate (DEHP)) and two alkylphenols (octylphenols (OP) and isomers of nonylphenol (NP)) were followed in greywater. For each sample, analyses were carried out on both the dissolved and particulate phases. Moreover, water quality parameters were also monitored, in order to find out whether or not any correlation exists between the concentration of the investigated contaminants and the quality of water. Water quality parameters studied are pH, total suspended solids (TSS), dissolved and particular organic carbon (DOC and POC), chemical and biochemical oxygen demands (COD and BOD5), total Kjeldahl nitrogen (TKN), and anionic detergents (methylene blue active substance or MBAS). This paper presents the methodology used to monitor two greywater with the most important volumes: showers and washing machines. These greywater showed high variability with regard to water quality parameters. Moreover, AP and PAE concentrations are given for the first time for these two types of greywater. All compounds except OP were observed in almost all samples in at least one of the two monitored phases. The concentrations varied between limit of quantification for OP and 102 μg/l for DEHP. The levels measured in washing machines were higher than those for showers for all compounds. For instance, median NP concentration in washing machines was 3.59 μg/l against 1.09 μg/l in showers, DEHP was observed at 102 μg/l in washing machines against 16.6 μg/l in showers. Variability of the results was explained by habits of individuals (shower time, number of products used…) but also by differences in product composition. However, each type of water exhibited the same distribution. NP was the most abundant AP (about 85 % of the total amount) while DEHP represented the two thirds of the PAE compounds. The partition coefficients (Kd in l/kg) were evaluated. The results showed that log Kd ranged between 2.1 (DEP) and 4.8 (DEHP). Log Koc presented similar trends lying in the 2.4 (DEP)-5.0 (DEHP) range. Finally, with regard to greywater quality, the application for greywater reuse is discussed.
Show more [+] Less [-]Occurrence and fate of acrylamide in water-recycling systems and sludge in aggregate industries
2015
Junqua, Guillaume | Spinelli, Sylvie | Gonzalez, Catherine
Acrylamide is a hazardous substance having irritant and toxic properties as well as carcinogen, mutagen, and impaired fertility possible effects. Acrylamide might be found in the environment as a consequence of the use of polyacrylamides (PAMs) widely added as a flocculant for water treatment. Acrylamide is a monomer used to produce polyacrylamide (PAM) polymers. This reaction of polymerization can be incomplete, and acrylamide molecules can be present as traces in the commercial polymer. Thus, the use of PAMs may generate a release of acrylamide in the environment. In aggregate industries, PAM is widely involved in recycling process and water reuse (aggregate washing). Indeed, these industries consume large quantities of water. Thus, European and French regulations have favored loops of recycling of water in order to reduce water withdrawals. The main goal of this article is to study the occurrence and fate of acrylamide in water-recycling process as well as in the sludge produced by the flocculation treatment process in aggregate production plants. Moreover, to strengthen the relevance of this article, the objective is also to demonstrate if the recycling system leads to an accumulation effect in waters and sludge and if free acrylamide could be released by sludge during their storage. To reach this objective, water sampled at different steps of recycling water process has been analyzed as well as different sludge corresponding to various storage times. The obtained results reveal no accumulation effect in the water of the water-recycling system nor in the sludge.
Show more [+] Less [-]Influence of microbubble in physical cleaning of MF membrane process for wastewater reuse
2015
Lee, Eui-Jong | Kim, Yŏng-hun | Kim, Hyŏng-su | Jang, Am
Currently, there is a growing emphasis on wastewater reclamation and reuse all over the world due to restricted water resources. Among a variety of wastewater reuse technologies, the use of microfiltration membranes (MF) is one of the popular processes because it has the ability to successfully eliminate particulates and colloidal matters. However, successful fouling control is not easy because effluents from the activated sludge process still contain small particulates and colloidal matters such as extracellular polymeric substance (EPS) and soluble microbial products (SMP). On the other hand, microbubbles have advantageous properties compared to common bubbles, but there hasn’t been reporting of the use of microbubbles in physical cleaning instead of aeration. Encouraging results were obtained herein through the application of microbubbles for physical cleaning. In evaluation of the cleaning efficiency, the efficiency of microbubbles was observed to be twice as high as that of aeration, except during the course of the initial 30 min. Total organic carbon (TOC) concentration of the membrane tank after treatment with microbubbles was more than twice as high as that after aeration for physical cleaning. The membrane cleaned with microbubbles also had the smoothest surface, with a roughness of 42.5 nm. In addition, microbubbles were found to effectively remove EPS and make the structure of the gel layer loose. In particular, the microbubbles had the ability to remove proteins through the effect of pyrolytic decomposition. Therefore, in FT-IR spectra of the membrane surfaces taken before and after physical cleaning, while each treatment showed similar peak positions, the peak values of the membrane treated with microbubbles were the lowest. Through various analyses, it was confirmed that microbubbles can remove foulants on the gel layer in spite of their very low shear force. This means that microbubble cleaning has full potential for use as a physical cleaning method in the wastewater reclamation process.
Show more [+] Less [-]Global sensitivity analysis for an integrated model for simulation of nitrogen dynamics under the irrigation with treated wastewater
2015
Sun, Huaiwei | Zhu, Yan | Yang, Jinzhong | Wang, Xiugui
As the amount of water resources that can be utilized for agricultural production is limited, the reuse of treated wastewater (TWW) for irrigation is a practical solution to alleviate the water crisis in China. The process-based models, which estimate nitrogen dynamics under irrigation, are widely used to investigate the best irrigation and fertilization management practices in developed and developing countries. However, for modeling such a complex system for wastewater reuse, it is critical to conduct a sensitivity analysis to determine numerous input parameters and their interactions that contribute most to the variance of the model output for the development of process-based model. In this study, application of a comprehensive global sensitivity analysis for nitrogen dynamics was reported. The objective was to compare different global sensitivity analysis (GSA) on the key parameters for different model predictions of nitrogen and crop growth modules. The analysis was performed as two steps. Firstly, Morris screening method, which is one of the most commonly used screening method, was carried out to select the top affected parameters; then, a variance-based global sensitivity analysis method (extended Fourier amplitude sensitivity test, EFAST) was used to investigate more thoroughly the effects of selected parameters on model predictions. The results of GSA showed that strong parameter interactions exist in crop nitrogen uptake, nitrogen denitrification, crop yield, and evapotranspiration modules. Among all parameters, one of the soil physical-related parameters named as the van Genuchten air entry parameter showed the largest sensitivity effects on major model predictions. These results verified that more effort should be focused on quantifying soil parameters for more accurate model predictions in nitrogen- and crop-related predictions, and stress the need to better calibrate the model in a global sense. This study demonstrates the advantages of the GSA on a more complete analysis of model input parameters and their interactions on the model output for nitrogen modeling.
Show more [+] Less [-]The application of advanced oxidation technologies to the treatment of effluents from the pulp and paper industry: a review
2015
Hermosilla, Daphne | Merayo, Noemí | Gasco Sidro, Antonio J. (Antonio José) | Blanco, Angeles
The paper industry is adopting zero liquid effluent technologies to reduce freshwater use and meet environmental regulations, which implies closure of water circuits and the progressive accumulation of pollutants that must be removed before water reuse and final wastewater discharge. The traditional water treatment technologies that are used in paper mills (such as dissolved air flotation or biological treatment) are not able to remove recalcitrant contaminants. Therefore, advanced water treatment technologies, such as advanced oxidation processes (AOPs), are being included in industrial wastewater treatment chains aiming to either improve water biodegradability or its final quality. A comprehensive review of the current state of the art regarding the use of AOPs for the treatment of the organic load of effluents from the paper industry is herein addressed considering mature and emerging treatments for a sustainable water use in this sector. Wastewater composition, which is highly dependent on the raw materials being used in the mills, the selected AOP itself, and its combination with other technologies, will determine the viability of the treatment. In general, all AOPs have been reported to achieve good organic removal efficiencies (COD removal >40 %, and about an extra 20 % if AOPs are combined with biological stages). Particularly, ozonation has been the most extensively reported and successfully implemented AOP at an industrial scale for effluent treatment or reuse within pulp and paper mills, although Fenton processes (photo-Fenton particularly) have actually addressed better oxidative results (COD removal ≈ 65–75 %) at a lab scale, but still need further development at a large scale.
Show more [+] Less [-]Ten key research issues for integrated and sustainable wastewater reuse in the Middle East
2015
Shomar, Basem | Dare, Anne
Wastewater management is not limited to the technology used to collect and treat wastewater. It begins with the early planning phase of building a society and includes considerations of how that society will grow. Therefore, history, culture, religion, and socioeconomy are important components to include in any relevant and integrated studies of wastewater management and reuse. Engineering, health, chemistry, biology, food production, cultural heritage, and the needs of people of all ages should be considered together when making management decisions regarding issues so intimately tied with humanity as water and sanitation. Other escalating challenges such as poverty, food, and water scarcity, migration and instability, flooding and catastrophes, diseases and mortality, etc. should also be considered as part of wastewater management and reuse planning. Emerging contaminants could be associated with the urbanization, modernization, and industrialization of several countries. Several arid countries have developed water security strategies where wastewater reuse is a major component. The existing wastewater treatment technologies in these countries are, in most cases, unable to remove such contaminants which may affect irrigation waters, industrial products, groundwater, etc. People would have to accept that the food on their tables could be irrigated with treated wastewater that they generated a few months ago, even if very advanced technologies were used to treat it. The purpose of this review is to highlight multidisciplinary areas of research on wastewater and to propose applicable and affordable mechanisms by which we may consider wastewater as a legitimate resource.
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