Treatment of rinsing water from electroless nickel plating with a biologically active moving-bed sand filter (original) (raw)
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Nickel removal from nickel plating waste water using a biologically active moving-bed sand filter
Biometals, 2003
Efficient removal of dissolved nickel was observed in a biologically active moving-bed 'MERESAFIN' sand filter treating rinsing water from an electroless nickel plating plant. Although nickel is fully soluble in this waste water, its passage through the sand filter promoted rapid removal of approximately 1 mg Ni/l. The speciation of Ni in the waste water was modelled; the most probable precipitates forming under the conditions in the filter were predicted using PHREEQC. Analyses of the Ni-containing biosludge using chemical, electron microscopical and X-ray spectroscopic techniques confirmed crystallisation of nickel phosphate as arupite (Ni 3 (PO 4 ) 2 .8H 2 O), together with hydroxyapatite within the bacterial biofilm on the filter sand grains. Biosorption contributed less than 1% of the overall sequestered nickel. Metabolising bacteria are essential for the process; the definitive role of specific components of the mixed population is undefined but the increase in pH promoted by metabolic activity of some microbial components is likely to promote nickel desolubilisation by others.
Environmental Processes, 2021
Α pilot scale packed-bed bio lm reactor was set up and monitored for the treatment of wastewater originating from the hydrometallurgical recovery of metals from printed circuit boards (PCBs). The wastewater is characterized by: (a) low pH, (b) residual soluble metal species and (c) elevated concentrations of nitrate and chloride originating from the use of nitric and hydrochloric acid as leaching agents. Such wastewater could be treated in a bioreactor capable for the simultaneous removal of metals and nitrates, through complete denitri cation, in presence of elevated chloride concentrations. However, the possible inhibitory effects of metals as well as the metals bioprecipitation should be investigated experimentally. Biological denitri cation was studied under extreme conditions in the bioreactor inoculated with Halomonas denitri cans: at (a) pH 3-8; (b) metal content (Cu, Ni, Zn and Fe) at 50 mg/L and 100 mg/L, respectively (c) nitrate concentration 750-5,750 mg/L NO 3 and (d) chloride concentration 5%-10% as NaCl. According to the results, denitri cation proceeds rapidly through the formation of nitrite as intermediate which is sequentially reduced completely to nitrogen. The presence of metals does not affect the denitri cation process. Iron, zinc, copper and nickel are sequestered from the wastewater via bioprecipitation. Both goals, namely metals removal and complete reduction of nitrate in presence of elevated concentrations of chloride, were successfully achieved by the treatment scheme. The proposed simple, robust and low-cost biological treatment unit is advantageous compared to the conventional wastewater treatment, based on metal precipitation via chemical neutralization, where the problem of nitrate removal remains unresolved.
During the last decade, considerable volume of work has been carried out by Institutes, Universities and private corporations on the development of novel biotechnological processes for the advanced treatment of metallurgical and mining liquid effluents. Reactors that can support the development and maintenance of biofilms, such as, static beds, fluidized beds, moving bed sand filters and rotating biological contactors (RBC), provide a variety of liquid effluent advanced treatment options for the above categories of effluents. Biofilm reactors, both in pilot and industrial scale, have been tested and the available results on pollutant sequestering are very promising. The successful development of biofilm reactors has been based both on the research advances on the characteristics of microbial biomass species and on the elucidation of the likely mechanisms of interaction between the microbial biomass and the targeted pollutants which include toxic metals, radionuclides and metalloid oxyanions. Microbial biomassmetals interactions occur through a variety of mechanisms. These mechanisms can be classified in two principal categories: the metabolically active (biomineralization, biotransformation, bioprecipiation) and metabollically passive (biosorptive) processes. Metabolic interactions between microbial biomass and metals or oxyanions in liquid effluent solutions may lead to metals precipitation (bioprecipitation), metals reduction (bioreduction) etc. Passive microbial biomass-metal/metalloids interactions include extracellular, intracellular sequestering, chemical bonding, complexation and ion exchange mechanisms. This variety of metals sequestering mechanisms by microbial biomass, together with the low amounts of energy and materials required for their scale up and application, make biotechnological processes promising for efficient metal 280 removal and recycling at waste water polishing stage. The present paper summarizes the main process characteristics and some of the results available both in pilot and in industrial scale applications, including a list of references for further study on the subject.
Biofilm reactors, both in pilot and industrial scale, have been recently developed and tested for the advanced treatment of metallurgical and mining effluents.The successful development of biofilm reactors has been based both on the research advances on the characteristics of microbial biomass species and on the elucidation of the likely mechanisms of interaction between the microbial biomass and the targeted pollutants which include toxic metals, radionuclides and metalloid oxyanions. Microbial biomassmetals interactions occur through a variety of mechanisms. These mechanisms can be classified in two principal categories: the metabolically active (biomineralization, biotransformation, bioprecipiation) and metabollically passive (biosorptive) processes. Metabolic interactions between microbial biomass and metals or oxyanions in liquid effluent solutions may lead to metals precipitation (bioprecipitation), metals reduction (bioreduction) etc. Passive microbial biomass-metal/metalloids interactions include extracellular, intracellular sequestering, chemical bonding, complexation and ion exchange mechanisms. This variety of metals sequestering mechanisms by microbial biomass, together with the low amounts of energy and materials required for their scale up and application, make biotechnological processes promising for efficient metal removal and recycling at waste water polishing stage. Two examples of biofilm reactors applicable to the treatment of mining and metallurgical effluents as well as the biological mechanisms taking place during their operation are briefly presented in this paper.
Bioremediation of metal contamination
Environmental monitoring and assessment, 2003
A study was initiated to evaluate the use of the fungus Aspergillus niger for bioleaching and then to determine the effect of process steps, the tailings concentration and type of substrate. An oxidized mining tailing containing mainly copper (7240 mg kg(-1) tailings) was studied. A sucrose and mineral salts medium was initially used to produce citric and gluconic acids by A. niger at various concentrations of tailings ( 1, 5, 7, 10 and 15% w/v). Maximal removal of up to 60% of the copper was obtained for the 5% tailings when the organic acid supernatant was added to the tailings. In a single step process, A. niger was then grown in the presence of mining tailings at various concentrations. Maximum copper solubilization (63%) occurred with 10% mining tailings using sucrose as the substrate. Other substrates were then evaluated including molasses, corn cobs and brewery waste (10% mining tailings). Sucrose gave the best results for copper removal, followed by molasses, corn cobs and b...
INTERNATIONAL CONFERENCE ON SCIENCE AND APPLIED SCIENCE (ICSAS) 2019, 2019
Electroplating industry is a producer of heavy metal waste such as nickel. When disposed of directly in the waters, it will cause water pollution. The methods of sewage treatment have been done in a variety of chemical and biological ways. Chemical methods include adsorption, precipitation, electrodialysis, electrocoagulation, while biological methods include biosorption and bioremediation. Bioremediation is a waste treatment process using microbes that aims to degrade pollutants in the environment. Bioremediation of heavy metal nickel in electroplating industrial wastewater is done by adding Bacillus subtilis bacteria so that it can reduce the level of nickel in it. In this research, industrial liquid waste samples of electroplating were initially processed using electrocoagulation. The initial sample still contained a nickel level of 2.1425 ppm. Subsequently, bioremediation was carried out using Bacillus subtilis with varying concentrations of 10 2.5 cells/ml and 10 5 cells/ml and incubated for 24 hours. The nickel heavy metal content is further determined by the atomic absorption spectrophotometry (AAS). Results showed that bioremediation using 10 2.5 cells/ml and 10 5 cells/ml of Bacillus subtilis could lower nickel levels at the rate of 85.61% and 75.24% respectively. Concentrations of 10 2.5 cells/ml Bacillus subtilis decreases significantly higher nickel levels to the concentration of 10 5 cells/ml Bacillus subtilis.
Opportunities and Challenges in Bio Treatment of Industrial Waste Water
2019
Microorganisms have a tremendous influence on their environment through the transfer of energy, charge, and materials across a complex biotic mineral–solution interface. The bio-modification of mineral surfaces involves the complex action of microorganism on the mineral surface. The manner, in which bacteria affect the surface reactivity and the mechanism of adsorption and accumulation of the primary data in this area are only starting. Bio-Processing involves the selective removal of undesirable mineral constituents from an ore through microbe-mineral interactions in the processes such as selective flotation and flocculation. At the same time, bio-sorption has made a considerable progress in moving from theory to industrial practice as it is not only environmental useful but also more economical than many other processes. The bioflotation, bio-flocculation and bio-sorption processes concern the mineral response to the bacterium presence, which is essentially interplay between micro...
The Use of Industrial Waste for the Bioremediation of Water Used in Industrial Processes
Water Chemistry [Working Title], 2019
Recently the interest in the remediation of liquid effluents from industries such as paint manufacturing, leather tanning, etc. has increased, because the quality of the water used in these processes is highly compromised and is generally discarded without any process of purification, causing an inadequate use of water and contributing to the hydric stress of the planet. Therefore, it is necessary to find alternatives for the remediation of water used in industrial processes; one of the methods that has been widely accepted given its high efficiency, low cost, and versatility compared to others is the bioadsorption using materials derived from various processes used for the elimination of metals such as Cr, Co, Cu, Ni, etc. from liquid effluents. Among the materials used for this purpose are rice husk, orange, and wheat as well as apatite (hydroxyapatite and brushite), derived from animal bones, which have shown good capacity (>90%) to adsorb metals from aqueous solutions. Through the characterization by DRX, FTIR, and SEM, of the brushite and studies in equilibrium and kinetics of adsorption, it has been demonstrated that this material has a good capacity to remove metals present in water.