Chromium is a common groundwater pollutant originating from industrial processes such as metal plating, leather tanning and pigment manufacturing. Permeable reactive barriers (PRBs) have proven to be viable and cost-effective systems for remediation of chromium contaminated groundwater at many sites. The purpose of this research presented in this thesis is to focus on two parameters that affect the performance of PRB on chromium removal, namely the concentration of reactive media and groundwater flux by analyzing the data obtained from laboratory column studies. Laboratory scale columns packed with different amounts of iron powder and quartz sand mixtures were fed with 20 mg/l chromium influent solution under different fluxes. When chromium treatment efficiencies of the columns were compared with respect to iron powder/quartz sand ratio, the amount of iron powder was found to be an important parameter for treatment efficiency of PRBs. The formation of H2 gas and the reddish-brown precipitates throughout the column matrix were observed, suggesting the reductive precipitation reactions. SEM-EDX analysis of the iron surface after the breakthrough illustrated chromium precipitation. In addition to chromium / calcium and significant amount of iron-oxides or -hydroxides was also detected on the iron surfaces. When the same experiments were conducted at higher fluxes, an increase was observed in the treatment efficiency in the column containing 50% iron. This suggested that the precipitates may not be accumulating at higher fluxes which, in turn, create available surface area for reduction. Extraction experiments were also performed to determine the fraction of chromium that adsorbed to ironhydroxides. The analysis showed that chromium was not removed by adsorption to oxyhydroxides and that reduction is the only removal mechanism in the laboratory experiments. The observed rate of Cr(VI) removal was calculated for each reactive mixture which ranged from 48.86 hour-1 to 3804.13 hour-1. These rate constants and complete removal efficiency values were thought to be important design parameters in the field scale permeable reactive barrier applications.

Clinoptilolite samples obtained from two deposits in Turkey were tested for their potential in removing cadmium from aqueous solutions. Preliminary experiments in batch mode revealed inferior cadmium uptake at low pH. Particle size was found to have no effect on cadmium removal efficiency suggesting the use of exchangeable cations found in the internal/available sites. Increasing temperature yielded positive, whereas prewashing had no effect on cadmium removal using both clinoptilolite samples. The Langmuir model fitted the equilibrium data for both samples better than the Freundlich model. The capacity reached after conditioning represents about 4 and 3 fold increase for G&ouml / rdes and Bigadi&ccedil / samples, respectively. The relatively poor performance of Bigadi&ccedil / clinoptilolite was due to low clinoptilolite/high impurity contents. Further studies were carried out only with G&ouml / rdes clinoptilolite. The performance of the G&ouml / rdes samples conditioned with various chemicals were NaCl&gt / KCl&gt / As-received&gt / CaCl2&gt / HCl. 20BV of NaCl solution was found to be sufficient with no pH adjustment or water quality requirement during column conditioning. In column experiments, among the tested flowrates 5, 10 and 15 BV/hr, highest flowrate indicated inferior utilization of the removal capacity. No significant difference by decreasing particle size indicated pore diffusion resistance not to be a limiting factor. In five conditioning and regeneration cycles, clinoptilolite exhibited 36% increase in operating capacity. Cadmium removed by clinoptilolite in progressing cycles was concentrated by about 7 times. Overall, this study shows that Manisa-G&ouml / rdes clinoptilolite is advantageous for the removal of cadmium ions from aqueous solutions and hold great potential to be used in practical applications.

In the present study, the recovery of the indigo dyeing rinsing wastewater originating from a denim textile mill to the degree of reuse quality, which generally requires nanofiltration (NF), was investigated. In order to control flux decline and hence to maintain an efficient NF / coagulation, microfiltration (MF) and sequential MF plus ultrafiltration (UF) pretreatment process alternatives were tested. All pretreatment alternatives were optimized to reduce chemical oxygen demand (COD) and color load to NF. Coagulation process was investigated using the coagulants, aluminum sulfate (Al2(SO4)3.18H2O) and ferric chloride (FeCl3.6H2O) by running a series of jar tests. The results showed that coagulation process did not provide an effective and efficient pretreatment due to high dose of coagulant requirement. MF tests run by using 0.45, 2.5 and, 8 &micro / m membranes indicated that MF through 0.45 &micro / m pore-sized membrane is the best process providing 64% color and 29% COD removals, leading to a color value of 2493 Pt-Co and COD of 892 mg /L in the permeate. Application of sequential MF+UF filtration provided a significant benefit over single MF in terms of rejections and also permeate flux. UF applied after MF provided additional 62% color and 4% COD removals leading to 960 Pt-Co color and 856 mg/L COD. NF tests conducted using pretreated wastewater via single MF and sequential MF+UF indicated that single MF is the best pretreatment to NF and this treatment scheme provided 99% color, 97% COD and 80 % conductivity removals and satisfied reuse criteria.

Rapid urbanization and population growth have represented a great challenge to water resources management, since wastewater generated in urban areas forms a non-conventional source, wastewater reuse is being recognized as a sustainable water management approach. This study focuses on with the potential and practibility of implementing wastewater reuse techniques in Izmir region, especially with the aim to use treated wastewater and nutrient for agriculture. To this end, qualititative and quantitative agricultural water demand were considered. This thesis introduces a wastewater reuse planning model and optimization method with an emphasis on the wastewater treatment technology used as well as the agricultural demand in the area of the study. The model was developed with considerations over water quality, wastewater treatment and discharge. The objective of the model is to upgrade existing wastewater treatment plants or to design new treatment plants in regard to reuse wastewater in agriculture. The model is also capable of comparing treatment technologies from the point of design and cost. Three case studies were represented so as to demonstrate the modeling process and optimization studies for agricultural irrigation.

M. Tech. Chemical Engineering. / Discusses the HybridICE filter as a new but economical device for separating the ice from the slurry in freeze desalination processes. There is no direct information in the literature on the filter so there is a need to describe the principles behind the operation. There is also a need to investigate the filtering process in order to increase yield and purity of the ice produced. No design method exists for the filter. A design method has to be established so that when the required flow-rate is determined, the dimensions of the filter can be calculated.

A membrane based treatment scheme was developed for the recovery of the print dyeing wastewaters (PDWs) and the acid dye bath wastewaters (ADBWs) of carpet manufacturing industry. The treatment schemes were developed by selecting the best pre-treatment and treatment processes among the alternatives of chemical precipitation (CP), microfiltration (MF), ultrafiltration (UF) and nanofiltration (NF). The best process train for PDW was CP+NF, where organic matter, color, turbidity and total hardness were removed at &gt / 95%. The alternative process train CP+UF also removed color and turbidity almost completely, however organic matter rejection was low, being 25% at highest. The quality of NF permeates were suitable for dyeing of light colors whereas UF permeates were suggested for washing of the printed carpets or dyeing of the dark colors. The best process train for ADBW was MF (1.0 mm)+NF, where organic matter rejection increased from 65% to 97% due to pH neutralization. Alternatively, sequential NF was required up to three stages in order to achieve similarly high rejections at the acidic pH of ADBW. Therefore, pH neutralization was realized to be a very important operational parameter affecting the treatment scheme. Although pH neutralization increased the flux declines by almost 5%, chemical cleaning was very effective to restore the original fluxes. Finally, ADBW was mixed with PDW, which already had a pH around neutral, so that the pH of ADBW would rise towards neutral without chemical consumption. The results suggested that these wastewaters could be treated together as long as they were mixed up to equal volumes at pH around neutral. Therefore, a final treatment scheme, which involved single NF for the mixture of PDW and ADBW, following their individual pre-treatment stages, was proposed as the most efficient process train.

SILVA, Francisco Leandro Barbosa da . Respostas de plantas de feijão-de-corda à aplicação de biofertilizantes via foliar, sob condições de baixa e alta salinidade. 2011. 64 f. : Dissertação (mestrado) - Universidade Federal do Ceara, Centro de Ciências Agrárias, Departamento de Engenharia Agrícola, Programa de Pós-Graduação em Engenharia Agrícola, Fortaleza-CE, 2011. / Submitted by demia Maia (demiamlm@gmail.com) on 2016-07-04T12:39:21Z No. of bitstreams: 1 2011_dis_flbsilva.pdf: 1294765 bytes, checksum: b251b7430c83296db4d9b68caf60b016 (MD5) / Approved for entry into archive by demia Maia (demiamlm@gmail.com) on 2016-07-04T12:39:44Z (GMT) No. of bitstreams: 1 2011_dis_flbsilva.pdf: 1294765 bytes, checksum: b251b7430c83296db4d9b68caf60b016 (MD5) / Made available in DSpace on 2016-07-04T12:39:44Z (GMT). No. of bitstreams: 1 2011_dis_flbsilva.pdf: 1294765 bytes, checksum: b251b7430c83296db4d9b68caf60b016 (MD5) Previous issue date: 2011 / Faced with the need to seek higher yields and lower costs in saline areas, the use of organic fertilizers has been widely used in agriculture, as is the case of bovine biofertilizer, but studies show that its use as a minority of the adverse effects of salinity, has been little studied. The objective of this study was to evaluate the responses of cowpea to foliar application of biofertilizer under salinity conditions. The survey was conducted at the experimental farm Vale of Curu, at Pentecoste, Ceará, from november 2010 to january 2011. The plants were arranged in a split plot arrangement in a randomized block design with four blocks. The plot consisted of four different concentrations of salts in irrigation water via drip (0.5, 2.2, 3.6 and 5.0 dS m-1) and the subplots consisted of four levels of biofertilizers, corresponding to 0 , 15, 30 and 45% of the volume applied. The irrigation with saline water was dripping through and salts used to prepare the treatments were: NaCl, CaCl 2 .2H 2 O, MgCl 2 .6H 2 O in the proportion 7:2:1. In biofertilizer preparation was used fresh cattle manure and water in proportion (1:1). The doses of biofertilizers were applied weekly until the beginning of flowering. During the experiment were made manual weeding to control weeds and application of pesticides to control pathogens. In conducting the experiment were checked gas exchange, vegetative growth and assessed at the end of the pods were collected to assess productivity. Salinity influenced gas exchange (photosynthesis, stomatal conductance and internal CO 2 concentration), growth (dry matter and total), production (grain weight and yield) and nutrients (K / Na), without influence in other levels of minerals, nor the accumulation of salts in the soil. The influence of low salinity in the variables occurred due to high levels of rainfall (233.0 mm) during the experiment. Generally no significant effect was observed in the foliar application of biofertilizer, showing that application does not lessen the effect of saline irrigation. Due to the low influence of the biofertilizer the salinity of the water, it can be stated that the application can not be recommended for cultivation, requiring more studies, both in the form of application, as in proportion to be applied. / Diante da necessidade de se buscar altas produtividades e menores custos em áreas salinizadas, o uso de fertilizantes orgânicos vem sendo muito utilizado na agricultura, como é o caso do biofertilizante bovino, entretanto estudos mostram que sua utilização, como minorador dos efeitos adversos da salinidade, vem sendo pouco estudada. Objetivou-se com esse trabalho avaliar as respostas de plantas de feijão-de-corda à aplicação foliar de biofertilizante, sob condições de salinidade. A pesquisa foi realizada na fazenda experimental do Vale do Curu, em Pentecoste, Ceará, entre novembro de 2010 a janeiro de 2011. As plantas foram dispostas em um arranjo de parcelas subdivididas, no delineamento em blocos ao acaso, com quatro blocos. As parcelas consistiram de quatro diferentes concentrações de sais na água de irrigação, via gotejamento (0,5, 2,2, 3,6 e 5,0 dS m -1) e as subparcelas consistiram de quatro níveis de biofertilizante, correspondendo a 0, 15, 30 e 45% do volume aplicado. A irrigação com água salina foi via gotejamento e os sais utilizados para preparar os tratamentos foram: NaCl, CaCl 2 .2H 2 O, MgCl 2 .6H 2 O, na proporção 7:2:1. No preparo do biofertilizante foi usado esterco bovino fresco e água na proporção (1:1). As doses de biofertilizantes foram aplicadas semanalmente, até o inicio da floração. Durante o experimento foram feitas capinas manual, para o controle de ervas daninhas e aplicação de defensivos no controle de patógenos. Na condução do experimento foram verificadas trocas gasosas, avaliada o crescimento vegetativo e ao final foram coletas as vagens para avaliação da produtividade. A salinidade influenciou as trocas gasosas (fotossíntese, condutância estomática e concentração interna de CO 2 ), crescimento (matéria seca e total), produção (peso de grãos e produtividade) e nutrientes (relação K/Na), sem influência nos demais teores de minerais, nem tampouco no acúmulo destes sais no solo. A baixa influência da salinidade nas variáveis analisadas ocorreu, devido aos elevados índices de chuva (233,0 mm), durante o experimento. De um modo geral não foi observado efeito significativo na aplicação do biofertilizante via foliar, mostrando que aplicação não minorou o efeito da salinidade de irrigação. Devido à baixa influência do biofertilizante à salinidade da água, pode-se afirmar que, a aplicação pode não ser a recomendada para a cultura, necessitando de mais estudos, tanto na forma de aplicação, quanto na proporção a ser aplicado.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / Diante da necessidade de se buscar altas produtividades e menores custos em Ãreas salinizadas, o uso de fertilizantes orgÃnicos vem sendo muito utilizado na agricultura, como à o caso do biofertilizante bovino, entretanto estudos mostram que sua utilizaÃÃo, como minorador dos efeitos adversos da salinidade, vem sendo pouco estudada. Objetivou-se com esse trabalho avaliar as respostas de plantas de feijÃo-de-corda à aplicaÃÃo foliar de biofertilizante, sob condiÃÃes de salinidade. A pesquisa foi realizada na fazenda experimental do Vale do Curu, em Pentecoste, CearÃ, entre novembro de 2010 a janeiro de 2011. As plantas foram dispostas em um arranjo de parcelas subdivididas, no delineamento em blocos ao acaso, com quatro blocos. As parcelas consistiram de quatro diferentes concentraÃÃes de sais na Ãgua de irrigaÃÃo, via gotejamento (0,5, 2,2, 3,6 e 5,0 dS m -1) e as subparcelas consistiram de quatro nÃveis de biofertilizante, correspondendo a 0, 15, 30 e 45% do volume aplicado. A irrigaÃÃo com Ãgua salina foi via gotejamento e os sais utilizados para preparar os tratamentos foram: NaCl, CaCl 2 .2H 2 O, MgCl 2 .6H 2 O, na proporÃÃo 7:2:1. No preparo do biofertilizante foi usado esterco bovino fresco e Ãgua na proporÃÃo (1:1). As doses de biofertilizantes foram aplicadas semanalmente, atà o inicio da floraÃÃo. Durante o experimento foram feitas capinas manual, para o controle de ervas daninhas e aplicaÃÃo de defensivos no controle de patÃgenos. Na conduÃÃo do experimento foram verificadas trocas gasosas, avaliada o crescimento vegetativo e ao final foram coletas as vagens para avaliaÃÃo da produtividade. A salinidade influenciou as trocas gasosas (fotossÃntese, condutÃncia estomÃtica e concentraÃÃo interna de CO 2 ), crescimento (matÃria seca e total), produÃÃo (peso de grÃos e produtividade) e nutrientes (relaÃÃo K/Na), sem influÃncia nos demais teores de minerais, nem tampouco no acÃmulo destes sais no solo. A baixa influÃncia da salinidade nas variÃveis analisadas ocorreu, devido aos elevados Ãndices de chuva (233,0 mm), durante o experimento. De um modo geral nÃo foi observado efeito significativo na aplicaÃÃo do biofertilizante via foliar, mostrando que aplicaÃÃo nÃo minorou o efeito da salinidade de irrigaÃÃo. Devido à baixa influÃncia do biofertilizante à salinidade da Ãgua, pode-se afirmar que, a aplicaÃÃo pode nÃo ser a recomendada para a cultura, necessitando de mais estudos, tanto na forma de aplicaÃÃo, quanto na proporÃÃo a ser aplicado. / Faced with the need to seek higher yields and lower costs in saline areas, the use of organic fertilizers has been widely used in agriculture, as is the case of bovine biofertilizer, but studies show that its use as a minority of the adverse effects of salinity, has been little studied. The objective of this study was to evaluate the responses of cowpea to foliar application of biofertilizer under salinity conditions. The survey was conducted at the experimental farm Vale of Curu, at Pentecoste, CearÃ, from november 2010 to january 2011. The plants were arranged in a split plot arrangement in a randomized block design with four blocks. The plot consisted of four different concentrations of salts in irrigation water via drip (0.5, 2.2, 3.6 and 5.0 dS m-1) and the subplots consisted of four levels of biofertilizers, corresponding to 0 , 15, 30 and 45% of the volume applied. The irrigation with saline water was dripping through and salts used to prepare the treatments were: NaCl, CaCl 2 .2H 2 O, MgCl 2 .6H 2 O in the proportion 7:2:1. In biofertilizer preparation was used fresh cattle manure and water in proportion (1:1). The doses of biofertilizers were applied weekly until the beginning of flowering. During the experiment were made manual weeding to control weeds and application of pesticides to control pathogens. In conducting the experiment were checked gas exchange, vegetative growth and assessed at the end of the pods were collected to assess productivity. Salinity influenced gas exchange (photosynthesis, stomatal conductance and internal CO 2 concentration), growth (dry matter and total), production (grain weight and yield) and nutrients (K / Na), without influence in other levels of minerals, nor the accumulation of salts in the soil. The influence of low salinity in the variables occurred due to high levels of rainfall (233.0 mm) during the experiment. Generally no significant effect was observed in the foliar application of biofertilizer, showing that application does not lessen the effect of saline irrigation. Due to the low influence of the biofertilizer the salinity of the water, it can be stated that the application can not be recommended for cultivation, requiring more studies, both in the form of application, as in proportion to be applied.

No description available.

Freshwater scarcity is a dire problem for exposed human societies and natural ecosystems—a problem expected to grow worse with anticipated climate change. Reverse osmosis (RO) desalination is currently the most energy-efficient and ubiquitous desalination process used for freshwater production in water-scarce regions. The synergy of high solar radiation and significantly reduced costs in photovoltaics (PV) creates the opportunity for PV to become a dominant and sustainable solution for powering the energy-intensive process of desalination and reducing greenhouse gas emissions.While photovoltaic-powered reverse osmosis (PVRO) is a promising technological solution, several significant challenges must be further addressed to sustain high RO performance. First, the inherently intermittent nature of solar energy generation can adversely affect the freshwater conversion process and thereby decrease water recovery and quality. Furthermore, global desalination capacity is dominated by large-scale plants, whereas PVRO systems are currently limited to small-scale systems. Thus, to truly integrate renewable energy with desalination systems in an impactful way, there is a need to explore pathways for modifying the RO process to enable flexible operation on a large-scale, in response to power variability. Furthermore, the techno-economic feasibility of flexible, renewable-powered RO processes and the potential benefits that could be provided to variable renewable energy (VRE) plants and the electric grid warrants investigation. Brine minimization is another major challenge for sustainable desalination. Brine management is especially an issue for inland desalination plants. Novel approaches that are less costly and less energy intensive are needed to facilitate minimal and zero liquid discharge. To enable high-salinity desalination, several variations of osmotically assisted RO, which each surpass the pressure limitation of conventional RO, have been proposed in the literature but require further assessment. The promise of these enhanced RO approaches entails a reduction in energy consumption when compared with thermal desalination methods. The primary deliverables and novel contributions of this thesis include the development of (i) design, simulation, and cost optimization models for variable-powered, variable-salinity RO systems, (ii) module-scale, cost-optimization models for enhanced RO technologies that reduce transmembrane osmotic pressure to enable high-salinity desalination and brine minimization, (iii) examining the effects of cyclic reverse osmosis on inorganic scaling mitigation, and (iv) quantifying the availability of unconventional, alternative water sources to alleviate local water scarcity in the contiguous US. First, the techno-economic feasibility of PV-powered RO desalination plants in the Gulf region was assessed using Hybrid Optimization Model for Electric Renewables (HOMER) and Desalination Economic Evaluation Program (DEEP) to model both the power system and desalination system, respectively. Subsequently, an hourly simulation model for desalination was developed to replace the use of DEEP in the workflow. Grid-connected and off-grid cases with combinations of PV, batteries, and diesel generators were evaluated primarily by the levelized cost of electricity (LCOE) and levelized cost of water (LCOW). The shortcoming of conventional and PV-powered RO is that variable power compromises cumulative water production, which in turn increases water costs. Thus, we proposed the concept of active-salinity-control reverse osmosis (ASCRO) which enables control of the transmembrane osmotic pressure and water production in response to variable power. The ASCRO system dynamically controls energy consumption by operating across a range of feed salinity, allowing it to shift over a wide range of pump feed flows and pressures. To accomplish this, ASCRO utilizes feedwater from both low- and high-salinity sources. Enabling a dynamic power consumption profile can enhance demand-response capabilities, compensating for stressors on the grid. Moreover, ASCRO can improve the integration of renewable energy (RE) by responding to power fluctuations without compromising permeate production. This system can include on-site RE and energy storage to power the ASCRO plant and provide services to the grid. We considered the following grid-connected scenarios: 1) ASCRO, 2) ASCRO and battery storage, 3) ASCRO and photovoltaics (PV), and 4) ASCRO, battery storage, and PV. The LCOW was minimized by providing load-shifting and regulation capacity services in the California Independent System Operator (CAISO) market. We quantified that the ASCRO plant can ramp from minimum to maximum load within 84 seconds, which is adequate for participation in fast-timescale markets. The LCOW for these scenarios ranged from 49 – 59 cents/m³. We also present sensitivity analyses showing the effects of capital cost, CAISO market prices, and PV size on LCOW. To investigate alternative pathways to minimal and zero liquid discharge, low-salt rejection reverse osmosis (LSRRO), cascading osmotically mediated reverse osmosis (COMRO), and osmotically assisted reverse osmosis (OARO) were comparatively assessed via module-scale, cost optimization models to gain an accurate perspective of the performance differences between each of these configurations. We quantified the optimal LCOW of each technology for the case of desalinating feedwater at 70 g/L at 75% recovery, which would result in a brine concentration near 250 g/L, a level that allows further treatment with crystallizers. For baseline scenarios, LCOW results for OARO, COMRO, and LSRRO were 5.14, 7.90, and 6.63 $/m³ of product water, respectively, while the corresponding specific energy consumption (SEC) values were 10.31, 12.77, and 28.90 kWh/m³. A sensitivity analysis is also presented. Additionally, we sought to examine the possibility of whether adaptive RO operation could provide the added benefit of fouling mitigation. Using the Pitzer model, nucleation theory, and dissolution kinetics to guide a set of bench-scale fouling experiments, CaSO₄-NaCl solution, supersaturated with respect to gypsum, was fed through a membrane test cell to determine nucleation induction times, rates of flux decline, and scale reversal. Lastly, a geospatial analysis was conducted to estimate volumes of water deficits and potential alternative water sources for the contiguous US. Namely, wastewater effluent, brackish groundwater, agricultural drainage water, and produced water were considered in this analysis as alternatives for alleviating water scarcity. We formulated a conservative estimate of groundwater availability based on environmental flow limits. Additionally, agricultural drainage volumes were estimated based on USGS water use data. Overall, the results showed that water deficits amounted to an equivalent daily capacity of 149 million m³/day—nearly 50% more than the desalination capacity of the world in 2020. Furthermore, the total availability of alternative water sources was estimated to be between 192 – 240 million m³/day, but most of this volume was not in the same location as deficits. Thus, 58 – 65% of national water deficits would have to be alleviated via long-range transport. Additionally, the potential for integrating desalination and water reuse by interconnecting existing RO plants with wastewater treatments plants was also assessed.