Total and hexavalent chromium removal in a subsurface horizontal flow (h-SSF) constructed wetland operating as post-treatment of textile wastewater for water reuse

2011 ◽  
Vol 64 (4) ◽  
pp. 826-831 ◽  
Author(s):  
D. Fibbi ◽  
S. Doumett ◽  
I. Colzi ◽  
E. Coppini ◽  
S. Pucci ◽  
...  
Keyword(s):  
Hexavalent Chromium ◽  
Constructed Wetland ◽  
Water Reuse ◽  
Textile Wastewater ◽  
Trivalent Chromium ◽  
Post Treatment ◽  
Chromium Removal ◽  
Treatment Efficiency ◽  
Reed Bed

In this study we investigated total and hexavalent chromium removal in an h-SSF constructed wetland (CW) planted with Phragmites australis and operating as post-treatment of effluent wastewater from an activated sludge plant serving the textile industrial district of Prato (Italy). Two measurement campaigns were carried out in 2006 and 2008–2010 in which more than 950 inlet and outlet samples were analyzed. When inlet and outlet concentrations were compared one to the other, the latter were found to be significantly lower than the former (p < 0.001); during the entire period of investigation, removal of hexavalent chromium equal to about 70% was achieved. Outlet concentrations ranged between values lower than the quantification limit (0.5 μg L−1) and 4.5 μg L−1, and in all cases were therefore lower than the limit indicated for hexavalent chromium in the Italian regulation for water reuse (5 μg L−1). The comparison of the removal efficiencies achieved for hexavalent and trivalent chromium during the two campaigns suggested that the removal of the former can be sustained in the long term, while for the latter, the treatment efficiency is more sensitive to the age of the CW, being that it is it based on trivalent chromium retention in the reed bed.

scholarly journals effectiveness of indigenous local microorganisms in degrading hexavalent chromium (Cr(VI)) in Batik liquid waste

2021 ◽  
Vol 1 (1) ◽  
pp. 19-29
Author(s):  
Reza Fauzi Dwisandi ◽  
Frista Mutiara ◽  
Elsa Nurfauziah ◽  
Vita Meylani
Keyword(s):  
Hexavalent Chromium ◽  
High Efficiency ◽  
Waste Treatment ◽  
Liquid Waste ◽  
High Growth ◽  
Textile Wastewater ◽  
High Growth Rate ◽  
Gram Negative Bacteria ◽  
Small And Medium Industry

The batik industry in Indonesia has an IKM (Small and Medium Industry) scale so that it does not yet have adequate waste treatment. In the long term, waste is disposed of directly into the environment which can damage aquatic ecosystems and harm human health. Textile wastewater has a complementary picture and has a deep color. One of the most dangerous heavy metals contained in textile waste is hexavalent chromium (Cr(VI)). Several ways can be done to reduce hexavalent chromium (Cr(VI)) by bioremediation. Based on the results of the literature review, it shows that the bioremediation agents from single isolate microorganisms that are most effective in degrading chromium with high efficiency are Bacillus subtilis and Pseudomonas aeruginosa. The most effective consortium servers with constant reduction rates are the consortium of bacteria genus Mesophilobacter, Methylococcus, Agrobacterium, Neisseria, Xanthobacter, Deinococcus, Sporosarcina, and Bacillus by reducing BOD levels by 85.71%. The hexavalent chromium-degrading microorganisms are characterized by the presence of chromate reductase enzymes, mostly gram-negative bacteria, and a high growth rate.

Constructed wetland treatment system in textile industry and sustainable development

2008 ◽  
Vol 58 (10) ◽  
pp. 2017-2023 ◽  
Author(s):  
L. C. Davies ◽  
I. S. Pedro ◽  
R. A. Ferreira ◽  
F. G. Freire ◽  
J. M. Novais ◽  
...  
Keyword(s):  
Constructed Wetland ◽  
Textile Industry ◽  
Water Reuse ◽  
Textile Wastewater ◽  
Vertical Flow ◽  
Efficient Treatment ◽  
Effluent Quality ◽  
Treated Effluent ◽  
Wetland Treatment ◽  
In Series

This study focuses on the evaluation of the adequacy and sustainability of a constructed wetland (CW), with vertical flow (VF) design to treat a strongly coloured textile wastewater. Secondly an accidental AO7 overloaded discharge (700 mg l−1) was studied. A set of three similar VFCW beds (3 × 1 m2), operating in series, allowed also the efficient treatment of the AO7 heavy loaded wastewaters. The treated effluent quality enables water reuse for irrigation purposes or within the process.

Influence of Dissolved Oxygen on Trivalent Chromium Removal from Wastewater by GQSS

2012 ◽  
Vol 251 ◽  
pp. 416-420
Author(s):  
Jun Guo Li ◽  
Yan Shi ◽  
Ling Hong Wei
Keyword(s):  
Dissolved Oxygen ◽  
Redox Potential ◽  
Significant Influence ◽  
Steel Slag ◽  
Trivalent Chromium ◽  
Post Treatment ◽  
Chromium Removal ◽  
Lower Content ◽  
Solution Ph ◽  
Gas Quenching

Gas quenching steel slag (GQSS) without any post treatment and modification could be utilized to remove Cr(III) from wastewater. Due to lower content of reductive material in GQSS, it was suggested that dissolved oxygen in solution should be declined slightly to the minimum with libration time, and then increased as the testing centrifuge tubes without lids because of dissolution of oxygen from atmosphere. Dissolved oxygen chromium original have significant influence on redox potential in solution. pH increased with the increasing of libration time because of dissolution of alkaline material in GQSS. But dissolution oxygen has little influence on pH in solution. It was suggested that Cr(III) removal percentage when the solution was sealed from atmosphere was slightly higher than that as the soltuion without seal, which was related with the influence of dissolved oxygen on pH and redox potential in solution.

Key issues to consider when using alum sludge as substrate in constructed wetland

2015 ◽  
Vol 71 (12) ◽  
pp. 1775-1782 ◽  
Author(s):  
Xiaohong Zhao ◽  
Yaqian Zhao ◽  
Wenke Wang ◽  
Yongzhe Yang ◽  
Akintunde Babatunde ◽  
...  
Keyword(s):  
Constructed Wetland ◽  
Low Cost ◽  
High Strength ◽  
Dry Weight ◽  
Treatment Efficiency ◽  
Aluminium Sulphate ◽  
Key Issues ◽  
Alum Sludge ◽  
Biofilm Development

Globally, alum sludge is an easily, locally and largely available by-product from water treatment plants where aluminium sulphate is used as the coagulant for raw water purification. Owing to the high content of Al ions (29.7 ± 13.3% dry weight) in alum sludge and the strong affinity of Al ions to adsorb various pollutants especially phosphorus (P), alum sludge (in the form of dewatered cakes) has been investigated in recent years as a low-cost alternative substrate in constructed wetland (CW) systems to enhance the treatment efficiency especially for high strength P-containing wastewater. Long-term trials in different scales have demonstrated that the alum sludge-based CW is a promising technique with a two-pronged feature of using ‘waste’ for wastewater treatment. Alum sludge cakes in CW can serve as a medium for wetland plant growth, as a carrier for biofilm development and as a porous material for wastewater infiltration. After the intensive studies of the alum sludge-based CW system, this paper aims to address the key issues and concerns pertaining to this kind of CW system. These include: (1) Is alum sludge suitable for reuse in CWs? (2) Is Al released from the sludge a concern? (3) What is the lifespan of the alum sludge in CWs? (4) How can P be recovered from the used alum sludge? (5) Does clogging happen in alum sludge-based CW systems and what is the solution?

Membrane Treatment of Secondary Textile Effluents for Direct Reuse

1999 ◽  
Vol 40 (4-5) ◽  
pp. 409-416 ◽  
Author(s):  
A. Rozzi ◽  
M. Antonelli ◽  
M. Arcari
Keyword(s):  
Membrane Fouling ◽  
Water Reuse ◽  
Textile Wastewater ◽  
Pilot Scale ◽  
Post Treatment ◽  
Economical Analysis ◽  
Textile Dyeing ◽  
High Concentrations ◽  
Membrane Treatment

Post-treatment of secondary textile wastewater was tested at pilot scale on membrane modules (microfiltration MF, nanofiltration NF and reverse osmosis RO) for the direct reuse of polished effluent within the dyeing processes. The main polluting parameters monitored in the post-treatment were: organic compounds (COD), colour, surfactants and salinity (as conductivity). The first treatment scheme was made of ceramic MF followed by NF. Aluminium polychloride was added at high concentrations (of the order of 70 mg Al/L) to avoid MF membrane fouling. The quality of the final permeate, produced by NF fed on the MF permeate, was acceptable for water reuse. Clariflocculation (CF) plus multimedia filtration (MMF) followed by low-pressure RO was also tested. This process performed quite well: the RO module (p = 4 bar) ran for relatively long cycles (up to 80 hours) with 5% reduction of the permeate flow rate at a 10 L m−2 h−1 fluxes. A techno-economical analysis on the experimental data indicate that a high quality effluent (COD < 10 mg/l; conductivity < 40 μS/cm; negligible residual colour), to be recycled in the textile dyeing industry, may be produced at affordable costs (less than 0.25 ECU) from secondary textile wastewater.

Sign in / Sign up

Export Citation Format

Share Document