Optimization of a cationic dye desorption from a loaded-lignocellulosic biomass: factorial design experiments and investigation of mechanisms

The sustainable management of loaded adsorbents with organic pollutants represents an important environmental challenge. The current research work investigates the regeneration process optimization of raw orange tree sawdust (ROS) loaded with methylene blue (MB) by using NaCl solutions as eluent. The MB desorption was assessed in static mode under different process variables, notably the desorbing NaCl solution’s pH and concentration and the MB-loaded biomass dose. A full factorial design composed of 24 experiments was employed to apprehend the statistical significance of each followed parameter. Experimental results showed that the maximum desorption yield was estimated to be about 82.4% for the following parameter’s values: aqueous pH $=$ 3, [NaCl] $=$ 0.2 M and MB-loaded-ROS dosage in the desorbing solution $=$ 1 g$\cdot$L$^{-1}$. The statistical study confirmed the good fit of the experimental data with the statistical model used as well as regression and adjusted regression coefficients of about 99.0% and 96.6%, respectively. Moreover, the ranking of the effect of each studied parameter in terms of standardized effect on the desorption efficiency of MB from ROS was assessed through ANOVA test. The desorption mechanisms involved were explored by using multiple analysis techniques. It appears that the MB molecules’ desorption from ROS’s particles is mainly driven by a counter chemisorption process based on cationic exchange with the sodium and hydronium ions present in the desorbing solutions

Enhancement of rhizocompetence in pathogenic bacteria removal of a constructed wetland system

Preprin

Slaughterhouse Wastewater Treatment: A Review on Recycling and Reuse Possibilities

Slaughterhouses produce a large amount of wastewater, therefore, with respect to the increasing water scarcity, slaughterhouse wastewater (SWW) recycling seems to be a desirable goal. The emerging challenges and opportunities for recycling and reuse have been examined here. The selection of a suitable process for SWW recycling is dependent on the characteristics of the wastewater, the available technology, and the legal requirements. SWW recycling is not operated at a large scale up to date, due to local legal sanitary requirements as well as challenges in technical implementation. Since SWW recycling with single-stage technologies is unlikely, combined processes are examined and evaluated within the scope of this publication. The process combination of dissolved air flotation (DAF) followed by membrane bioreactor (MBR) and, finally, reverse osmosis (RO) as a polishing step seems to be particularly promising. In this way, wastewater treatment for process water reuse could be achieved in theory, as well as in comparable laboratory experiments. Furthermore, it was calculated via the methane production potential that the entire energy demand of wastewater treatment could be covered if the organic fraction of the wastewater was used for biogas production.DFG, 414044773, Open Access Publizieren 2021 - 2022 / Technische Universität Berli

The hydropolitical challenges of domestic water conservation: Palestine and Tunisia case studies

Southern Mediterranean area, particularly the Middle East and North Africa (MENA), has been facing social, economic, environmental and political challenges related to the water scarcity and quality. Within the European SWMED project, a socio-economic survey was conducted in Palestine and Tunisia, in order to explore the water conditions, and the social and economic situations of local families. The article illustrates the research design and implementation, as well as the main results that were used to select the appropriate sustainable water management solutions to respond to the hydropolitical issues. Due to the huge use of water in agriculture and the difficulty of reducing the water consumption in this sector, fostering tools for domestic water saving may be a winning strategy for facing water scarcity in MENA region.Fil: Anzera, Giuseppe. Università degli studi di Roma "La Sapienza"; ItaliaFil: Belotti, Francesca. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Università degli studi di Roma "La Sapienza"; ItaliaFil: Bousselmi, Latifa. Centre des Recherches et des Technologies des Eaux; TúnezFil: Rabi, Ayman. Palestinian Hydrology Group; Palestina (ANP

Adopting Sustainable Water Management Solutions under Social and Climate Change in Med Region: Cases from Palestine and Tunisia

The Southern Mediterranean region and particularly Middle East and North Africa (MENA) region are probably one of those regions that face serious social, economic, environmental and political challenges. Among the most critical challenges are the increasing water scarcity and,thus, demand, resulting mainly from climate change and rapid population growth. Based on United Nations’ estimates in 2006, the population of the region will reach about 255 million inhabitants in 2025, out of which 179 million people will be living in urban centers in this region. The current paper summarizes the main findings of the socioeconomic survey conducted with the aim to collect baseline socio-economic information to be used in selecting the appropriate sustainable water management (SWM) solutions that can be implemented in various settlement typologies in the region, selected in the view of the main results of this survey. Data have shown that both, simple and advanced solutions (such as tools for regulating the water flow, shower diffusers, WC “Water Saving”, wastewater and greywater treatment and reuse systems, rainwater harvesting at household level, etc.), respond sufficiently to the multiple and different needs of the settlement typologies in the region and help them to improve their adaptive capacity toward any potential changes (especially climate and demographic ones)

The role of lanthanum in the enhancement of photocatalytic properties of TiO2 nanomaterials obtained by calcination of hydrogenotitanate nanotubes

SSCI-VIDE+CARE:ECI2D+MME:ATR:HKO:CGU:GBEInternational audienceThe influence of lanthanum on the thermal stability and photocatalytic activity of calcined hydrogenotitanate nanotubes (HNT) was hereinevaluated. HNT samples were prepared through the hydrothermal treatmentof TiO2 P25 in a concentrated NaOH solution (11.25 M) at 130 degrees Cduring 20 h followed by acid washing. La-doped titanates nanotubes(La-HNT) photocatalysts with optimum 1 wt% of La were then elaborated byincipient wetness impregnation method using lanthanum nitrate asprecursor. La HNT and HNT samples were then calcined at temperaturesvarying between 400 degrees C and 700 degrees C. Samples werecharacterized by means of nitrogen adsorption-desorption isotherms at77K, X-ray diffraction (XRD), Raman spectroscopy, diffuse reflectancespectroscopy (DRS), photoluminescence spectroscopy (PL), transmissionelectron microscopy (TEM), ICP analysis and photocurrent experiments.The photocatalytic activities of La-HNT and HNT derived nanomaterialswere then evaluated through the photocatalytic degradation of formicacid (FA).Main results reveal that lanthanum inhibits TiO2 crystallite growthand retards anatase transformation into the less active rutile phase.The addition of La ions to TiO2 results in a charge imbalance creating ahigh proportion of oxygen vacancies as evidenced by photocurrent,photoluminescence and Raman experiments.The photocatalytic experiments reveal that La-doped TiO2 helps tomaintain a high photocatalytic activity level even after calcination athigh temperatures contrary to La-free photocatalysts. The determinationof kinetic parameters reveals that the maintaining of a highphotocatalytic activity results from the synergetic effect betweenrestriction of TiO2 crystallite size growth and formation of a highproportion of oxygen vacancies