ON-LINE MONITORING AND CONTROL OF THE TEXTILE WASTEWATER COLOR REMOVAL PROCESS

1994 ◽  
Vol 30 (3) ◽  
pp. 265-274 ◽  
Author(s):  
Cheng-Nan Chang ◽  
Ruey-Fang Yu ◽  
Allen C. Chao ◽  
Seishu Tojo

On-line monitoring of the wastewater color and ORP values is used to carry out laboratory studies for collecting data to assist in formulating model equations that can be used to achieve better control and automation of the oxidation process for color removal from textile finish wastewaters. Laboratory studies show that the ORP value, the solution pH, the chemical dosage applied and the resulting color of the treated samples are well correlated by linear relationships. Additionally, the ORP value of the solution that is highly related to the color or the ADMI value of the sample being oxidized can be used as a control parameter of the oxidation process. Nernst equation is modified to generalize the findings and the reaction kinetics can be delineated by Ct = In (ADMIo/ADMIt). The term Ct is a function of ORP, pH and reaction time while ADMIt and ADMI, are the color of the raw wastewater and the treated effluent, respectively. Using the model, the dosage requirement, the color removal efficiency, and the time required to complete the oxidation reaction can be calculated. On-line monitoring and automatic control of the de-coloring process to achieve a more efficient and better cost-effective color removal can be made practical.

2019 ◽  
Vol 22 (1) ◽  
pp. 31-36
Author(s):  
Forqan Mohammed ◽  
Khalid M. Mousa

In this study sunlight and UV radiation were used to compare the efficiency of decolorization of textile wastewater containing brilliant reactive red dye K-2BP (λmax = 534 nm) by the advanced oxidation process (AOP) using (H2O2/sunlight, H2O2/UV, H2O2/TiO2/sunlight, and H2O2/TiO2/UV). The results studied the effect of solution pH, applied H2O2 concentration, TiO2 concentration (nanoparticle), and initial dye concentration were studied. The experimental results showed that decolorization percentage with H2O2/sunlight and TiO2/H2O2/sunlight under the following conditions: - reaction time 150 of minutes, [ 500 ppm] H2O2, [100 ppm] TiO2, pH=3, initial dye concentration =15 ppm and at ambient temperature were 95.7% and 98.42% respectively. For the same conditions using H2O2/UV, H2O2/TiO2 /UV, the percentage of decolorization were 97.85% and 96.33% respectively. The results also indicated that the sunlight is more economic and cost-effective than UV radiation.


2014 ◽  
Vol 12 (24) ◽  
pp. 7-14
Author(s):  
Denise Alves FUNGARO ◽  
Sueli Ivone BORRELY ◽  
Marcela HIGA

Treatment of wastewater is one of the biggest problems faced by textile and dyestuff manufacturers. The purpose of the present study was to investigate the suitability of using zeolitic materials as low cost media for removal of color from dye effluents. Zeolite synthesized from cyclone ash (ZCA) was modified with hexadecyltrimethylammonium bromide and the adsorption efficiencies for unmodified and surfactant-modified zeolite (SMZCA) were studied using a batch equilibration method. SMZCA presented higher color removal efficiency than ZCA, removing 60-100% of color for textile effluents and around 39% for effluent of dyestuff manufacturing industry. The effects of dilution on color removal were evaluated. The pH values of the treated effluent were according to the Brazilian legislation. It can be concluded that surfactant modified-zeolite from cyclone ash is a promising low-cost adsorbent for color removal from textile wastewater.


Author(s):  
Teklit Gebregiorgis Ambaye ◽  
Kiros Hagos

Abstract In this study, the discoloration of wastewater containing azo dyes by chemical oxidation process combined with a biological treatment was evaluated and applied to real textile wastewater generated from one Ethiopian industrial site. The use of TiO2 as photocatalyst and the effect of the addition of H2O2 on color removal was first investigated. Photocatalysis was followed by aerobic biological treatment, and their combination resulted in a high extent of color removal (93.3%) and chemical oxygen demand (COD) reduction (90.4%). This was reached without pH correction and with low energy consumption compared to the implementation of AOPs alone. This study performed with real textile wastewater allows the direct extrapolation of the data for the design of a cost-effective and applicable treatment procedure at a pilot scale. Graphic abstract


2013 ◽  
Vol 8 (3-4) ◽  
pp. 469-478 ◽  
Author(s):  
Sandip S. Magdum ◽  
Gauri P. Minde ◽  
Upendra S. Adhyapak ◽  
V. Kalyanraman

The aim of this work was to optimize the biodegradation of polyvinyl alcohol (PVA) containing actual textile wastewater for a sustainable treatment solution. The isolated microbial consortia of effective PVA degrader namely Candida Sp. and Pseudomonas Sp., which were responsible for symbiotic degradation of chemical oxidation demand (COD) and PVA from desizing wastewater. In the process optimization, the maximum aeration was essential to achieve a high degradation rate, where as stirring enhances further degradation and foam control. Batch experiments concluded with the need of 16 lpm/l and 150 rpm of air and stirring speed respectively for high rate of COD and PVA degradation. Optimized process leads to 2 days of hydraulic retention time (HRT) with 85–90% PVA degradation. Continuous study also confirmed above treatment process optimization with 85.02% of COD and 90.3% of PVA degradation of effluent with 2 days HRT. This study gives environment friendly and cost effective solution for PVA containing textile wastewater treatment.


2021 ◽  
Vol 2 (1) ◽  
pp. 95
Author(s):  
Luca Dassi ◽  
Marco Merola ◽  
Eleonora Riva ◽  
Angelo Santalucia ◽  
Andrea Venturelli ◽  
...  

The current miniaturization trend in the market of inertial microsystems is leading to movable device parts with sizes comparable to the characteristic length-scale of the polycrystalline silicon film morphology. The relevant output of micro electro-mechanical systems (MEMS) is thus more and more affected by a scattering, induced by features resulting from the micro-fabrication process. We recently proposed an on-chip testing device, specifically designed to enhance the aforementioned scattering in compliance with fabrication constraints. We proved that the experimentally measured scattering cannot be described by allowing only for the morphology-affected mechanical properties of the silicon films, and etch defects must be properly accounted for too. In this work, we discuss a fully stochastic framework allowing for the local fluctuations of the stiffness and of the etch-affected geometry of the silicon film. The provided semi-analytical solution is shown to catch efficiently the measured scattering in the C-V plots collected through the test structure. This approach opens up the possibility to learn on-line specific features of the devices, and to reduce the time required for their calibration.


Author(s):  
Xueqiang Zhu ◽  
Lai Zhou ◽  
Yuncong Li ◽  
Baoping Han ◽  
Qiyan Feng

Cost-effective zero valent iron (ZVI)-based bimetallic particles are a novel and promising technology for contaminant removal. The objective of this study was to evaluate the effectiveness of CCl4 removal from aqueous solution using microscale Ag/Fe bimetallic particles which were prepared by depositing Ag on millimeter-scale sponge ZVI particles. Kinetics of CCl4 degradation, the effect of Ag loading, the Ag/Fe dosage, initial solution pH, and humic acid on degradation efficiency were investigated. Ag deposited on ZVI promoted the CCl4 degradation efficiency and rate. The CCl4 degradation resulted from the indirect catalytic reduction of absorbed atomic hydrogen and the direct reduction on the ZVI surface. The CCl4 degradation by Ag/Fe particles was divided into slow reaction stage and accelerated reaction stage, and both stages were in accordance with the pseudo-first-order reaction kinetics. The degradation rate of CCl4 in the accelerated reaction stage was 2.29–5.57-fold faster than that in the slow reaction stage. The maximum degradation efficiency was obtained for 0.2 wt.% Ag loading. The degradation efficiency increased with increasing Ag/Fe dosage. The optimal pH for CCl4 degradation by Ag/Fe was about 6. The presence of humic acid had an adverse effect on CCl4 removal.


2014 ◽  
Vol 41 (6) ◽  
pp. 499 ◽  
Author(s):  
David J. Will ◽  
Karl J. Campbell ◽  
Nick D. Holmes

Context Worldwide, invasive vertebrate eradication campaigns are increasing in scale and complexity, requiring improved decision making tools to achieve and validate success. For managers of these campaigns, gaining access to timely summaries of field data can increase cost-efficiency and the likelihood of success, particularly for successive control-event style eradications. Conventional data collection techniques can be time intensive and burdensome to process. Recent advances in digital tools can reduce the time required to collect and process field information. Through timely analysis, efficiently collected data can inform decision making for managers both tactically, such as where to prioritise search effort, and strategically, such as when to transition from the eradication phase to confirmation monitoring. Aims We highlighted the advantages of using digital data collection tools, particularly the potential for reduced project costs through a decrease in effort and the ability to increase eradication efficiency by enabling explicit data-informed decision making. Methods We designed and utilised digital data collection tools, relational databases and a suite of analyses during two different eradication campaigns to inform management decisions: a feral cat eradication utilising trapping, and a rodent eradication using bait stations. Key results By using digital data collection during a 2-year long cat eradication, we experienced an 89% reduction in data collection effort and an estimated USD42 845 reduction in total costs compared with conventional paper methods. During a 2-month rodent bait station eradication, we experienced an 84% reduction in data collection effort and an estimated USD4525 increase in total costs. Conclusions Despite high initial capital costs, digital data collection systems provide increasing economics as the duration and scale of the campaign increases. Initial investments can be recouped by reusing equipment and software on subsequent projects, making digital data collection more cost-effective for programs contemplating multiple eradications. Implications With proper pre-planning, digital data collection systems can be integrated with quantitative models that generate timely forecasts of the effort required to remove all target animals and estimate the probability that eradication has been achieved to a desired level of confidence, thus improving decision making power and further reducing total project costs.


Sign in / Sign up

Export Citation Format

Share Document