Water Resources and Industry最新文献

Sugarcane bagasse (SB) was used to produce a new bioadsorbent (STEA), drawing on circular economy concepts. STEA was synthesized using a two-step one-pot reaction, employing epichlorohydrin and triethylamine in the presence of N,N-dimethylformamide, without the use of a petroleum-based catalyst. The structure and surface of STEA were characterized by elemental C, H, N, and Cl analysis, X-ray diffraction, infrared spectroscopy, ¹³C solid-state nuclear magnetic resonance spectroscopy, thermogravimetric analysis, specific surface area and pore size distribution determination, and point of zero charge measurement. Batch adsorption and desorption tests were performed with the model dye Remazol Golden Yellow (RGY) RNL, a reactive anionic azo dye widely used in textile industry, to evaluate the potential reuse and application of STEA in a fixed-bed column for wastewater treatment. For batch adsorption, the best dose and agitation speed were 0.2 g L⁻¹ and 50 rpm, respectively. STEA effectively removed RGY over a wide range of pH (2.00–10.00). The equilibrium time, maximum adsorption capacity (Q_max), and desorption efficiency (E_des) were 720 min, 369 mg g⁻¹ (0.71 mmol g⁻¹), and 49.5 %, respectively. The fixed-bed column fed with a spiked aqueous RGY solution could be operated for 415 min, with Q_max of 422 mg g⁻¹ (0.81 mmol g⁻¹) and E_des of 58.9 %. Batch and continuous experiments using real textile industry wastewater containing reactive azo dyes showed high color removal efficiency by STEA, with no interference of other compounds present in wastewater on adsorption of the reactive azo dyes (overshooting effect). The technology was validated in a relevant environment and achieved technology readiness level 5, showing potential to be upscaled. Therefore, STEA proved to be an efficient bio-based technology for application in tertiary treatment of real textile plant wastewater to remove reactive anionic azo dyes.

Pulp and paper mill effluents represent a significant environmental concern due to the presence of various toxic organic and inorganic pollutants, posing risks even at low concentrations. With the paper production process consuming approximately 200 tons of water per ton of paper and generating effluents containing over 250 different chemicals, effective treatment methods are essential to mitigate the environmental impact of the pulp and paper (PP) industry. This study presents a comprehensive evaluation of the efficacy of heterogeneous and homogeneous photocatalytic treatments for PP industry-derived effluents, targeting reductions in major pollutant concentrations below environmental standards. A thorough review of the literature on pollutant removal from PP effluents using photocatalytic treatment, particularly employing UV/TiO₂ and UV/ZnO photocatalysts, reveals significant removal rates. Doped photocatalysts have shown enhanced performance, achieving removal percentages of 98 % for BOD and COD, and 99 % for color and lignin. Additionally, Fenton and photo-Fenton treatment techniques have demonstrated high removal efficiencies for BOD, COD, color, and lignin.

Seawater desalination has become an accessible option for augmenting freshwater supplies worldwide. In the countries of the Gulf Cooperation Council (GCC), it has been practiced for decades as the main source for domestic water use. Sustainable desalination requires addressing environmental impacts including damage to ecosystems from the high volumes of brine in the Gulf. This paper examines challenges related to environmental regulation of brine management in the Arab Gulf countries using the example of Qatar. It analyzes the brine challenge through infrastructure planning policies and stakeholders’ perceptions. The brine issue has been identified as a major environmental concern that requires action through discharge infrastructure, brine management technologies, and regulatory approaches based on quality thresholds and monitoring systems. Although there is a high level of agreement on the solvability of the brine issue, there are limitations with regard to the high reliance on desalination rendered through large-scale infrastructure. These limitations necessitate complementary water supply infrastructure for storage or the development of other sources through water reuse and storage. While water security considerations require prioritization of protection and supply continuity through desalination, incremental change through a stepwise dual approach of brine management and regulation is still possible.

Sequencing batch moving bed biofilm reactors have been widely used in commercial wastewater treatment facilities for organic carbon and nitrogen removal. However, these reactors can remove low phosphorus (P) levels. Therefore, this study investigated the potential of SB-MBBRs for maximizing simultaneous nitrification-denitrification and P removal (SNDPR) potential from P-rich municipal wastewater impacted by industrial discharges. A series of experiments were carried out to investigate the effect of external volatile fatty acid (VFA) dosing, airflow rate, and temperature on SNDPR using pilot-scale SBMBBRs. Stable and robust SNDPR was achieved with an optimum acetic acid supply of 150 mg SCOD/L, at 20 ^oC and 2.5 L air/min. A low airflow rate (AFR) and high-temperature conditions affected P release and uptake kinetics. Efficient PHA storage, dissolved oxygen (DO) transfer (outer layer), DO diffusion limitation (inner layer) of biofilm, and conversion of NH₄-N to NO₂-N/NO₃-N enhanced SNDPR in the two pilot SB-MBBRs.

Natural manganese oxides (n-MnOx) widely exist in the nature and may contribute to the elimination of organic contaminants. The present study investigated the degradation of frequently detected fluoroquinolone antibiotic enrofloxacin (EFX) and the degradation kinetics were analyzed. During the reaction, the valence of Mn in n-MnOx changed with the release of Mn ions. It was also found that combing manganese oxidizing bacteria with n-MnOx can enhance the degradation of EFX and alter the degradation pathway as well. The transformation products of EFX were analyzed with UPLC-MS/MS, which revealed seven products. Based on them, it is proposed that the degradation may start with the dehydrogenation from the piperazine moiety that was further broken down. Respirometry tests demonstrated that the degradation with n-MnOx significantly reduced the toxicity of EFX. This study proved the oxidation with n-MnOx as a simple and effective technology to remediate the contamination of enrofloxacin and other fluoroquinolones and the potential of combing the special capacity of microorganisms.

A comparative study of the results obtained from using Fenton and electro-Fenton processes in textile wastewater treatment is presented. Global indicators, color, COD, TOC, and BOD₅ were employed to investigate the treatments. Examination of the representative by-products gave new insights into Fenton. Even though the color removal was higher for classical Fenton (almost 100% color removal) than for electro-Fenton, the overall purification effect was not directly advantageous for Fenton. We found that electro-Fenton removed COD and TOC more efficiently. The biodegradability BI (BOD₅/COD) parameter was investigated, where the textile wastewater was hardly biodegradable (BI was 0.12 ± 0.007). BI of Fenton was also low (0.044 ± 0.006). Electro-Fenton yielded a considerably more promising result, where BI was 0.83 ± 0.15, and proved more bio-friendly than classical Fenton. Additionally, electro-Fenton was more efficient in by-product removal, especially the naphthalic component, with 90% removal (while Fenton removed 50%). The by-products influenced the after-treatment toxicity assessment of V. fischeri. The EC₅₀ values were below 2% and even lower for electro-Fenton. The results of the color matching parameters (DE_CMC) of re-dyeing were unacceptable using after-Fenton water at 8.66. DE_CMC results were between 1.01 and 2.71 after electro-Fenton treatment and had a recycling perspective.

In the present study, to minimize water consumption and reduce wastewater production in an oil refinery, a technique called water pinch analysis (WPA) was used with two single and double pollutant approaches. Total dissolved solids (TDS) and chemical oxygen demand (COD) were selected as the index pollutants. The results showed that the use of WPA has reduced the overall consumption of freshwater in the refinery on average between 79 m³/h (45%) in the single pollutant approach (77 m³/h for COD and 81 m³/h for TDS) and 99 m³/h (56%) in the double pollutant approach. It was also found that the volume of produced oily and sanitary effluents decreased between 31 and 52 m³/h. These findings show that WPA is a useful tool that can help make strategic decisions to minimize water consumption and modify consumption patterns in industries, and by reducing effluent production environmental risks will be reduced.

Anomalous water-consumption events (AEs) can significantly impact the functioning of water distribution networks, and their prompt identification can improve the service provided by water utilities. This study proposes a new methodology for AE detection and pre-localization in water distribution networks relying exclusively on pressure-data collected in the field, which are exploited to evaluate differential-pressure trends for all possible pressure-sensors couples located in the WDN. In greater detail, AEs are detected and pre-localized by analysing differential-pressure trends over time. The level of deviation of these trends from the standard is considered to provide information about (i) AE alert levels and (ii) the area of the network where the AE is most likely to occur. The application of the methodology to two real case studies featuring different characteristics in terms of residential and industrial users demonstrated method effectiveness in detecting and pre-localizing individual and simultaneous AEs of different magnitude and occurring at different times of the day, providing useful information about the presence of AEs without the need for hydraulic models, and allowing the evaluation of their effects in terms of piezometric head alteration in the different areas of the system.

The efficacy of magnesium oxide (MgO)-bentonite clay nanocomposite particles (MgO nanoparticles embedded in powdered bentonite clay) for water and wastewater treatment applications is examined herein. Congo red (CR), a widely used azo dye, was used as the model contaminant. For CR concentrations ≤120 mg/L, the optimum nanocomposite dosage was ≤1 g/L, achieving CR removal ≥99% for contact times (mixing durations) ≤10 min, whereas temperature and pH had no significant effect on the treatment process. The removal of CR dye followed the pseudo-second-order model than the first order model. Furthermore, adsorption isotherms followed the Langmuir adsorption isotherm rather than the Freundlich adsorption isotherm (R² ≥ 0.99), hence confirming monolayer homogenous adsorption. The surface morphological and physicochemical characteristics of the nanocomposite were also identified, and results suggest that CR removal was governed by electrostatic attraction between the protonated hydroxyl groups (i.e., -OH²⁺), embedded on the nanocomposite surface, and the negatively charged –SO₃-groups of the CR dye. When used for the treatment of real printing ink wastewater, CR was practically removed (⁓100%), whereas for real printing and dyeing wastewater (PDW), a more challenging effluent that also contains salts and other contaminants, CR removal was ≥80%. Overall, the produced MgO-bentonite clay nanocomposite hold great promise for sustainable CR removal, a typical contaminant that is released by many industries including printing, tannery and textile, paper, plastic, and paint and coatings.

This study explores a new governance mechanism aimed at regional integration and explains how this mechanism can achieve optimal governance of water resources through the division of labour in politics and the economy. This study adopts political economic geography as the research approach. The data used in the analysis were obtained from official documents, interviews and field investigations, and its authenticity was interactively checked via triangulation. The results show that ‘spatial shifts’ were the driving force behind water redistribution. The division of labour between politics and the economy eliminates obstacles to water distribution through the mutual adjustment and division of underground rhizomes; ‘creative destruction’ and ‘destructive creation’ are alternately used to achieve dialectical progress. This study concludes that in this case, the process of regional integration simultaneously generates circular mechanisms in which political power and economic productivity are consolidated.