Heavy metals removal from contaminated sewage sludge by naturally fermented raw liquid from pineapple wastes

2007 ◽  
Vol 56 (7) ◽  
pp. 145-152 ◽  
Author(s):  
Dominica Del Mundo Dacera ◽  
Sandhya Babel
Keyword(s):  
Citric Acid ◽  
Sewage Sludge ◽  
Metal Removal ◽  
Animal Feed ◽  
High Protein Content ◽  
Waste Sludge ◽  
Metals Removal ◽  
Treatment Facilities ◽  
Pineapple Pulp ◽  
Digested Sewage Sludge

The large amount of unutilised pineapple wastes produced every year in tropical countries, particularly in Thailand, adds to the existing environmental pollution problems of the country. This study investigated the utilisation of pineapple wastes to treat another form of waste (sludge) from wastewater treatment facilities in Thailand. Laboratory scale studies were carried out to determine the potential of using naturally fermented raw liquid from pineapple wastes as a source of citric acid in the extraction of Cr, Cu, Pb, Ni and Zn from anaerobically digested sewage sludge. Results of the leaching study revealed its effectiveness in extracting Zn (at 92%) at pH 3.67 and a short leaching time of only 2 h, and Ni at almost 60% removal at the same leaching time. Chromium removal was also high at almost 75% at a longer leaching time of 11 days. Variation in metal removal efficiencies may also be attributed to the forms of metals in sludge, with metals predominantly in the exchangeable and oxidisable phases showing ease of leachability (such as Zn). Compared to citric acid, at pH approaching 4.0, naturally fermented raw liquid seemed to be more effective in the removal of Zn and Cu at the same leaching time of 2 h, and Cr at a longer leaching time of 11 days. The pineapple pulp, which is a by-product of the process, can still be used as animal feed because of its high protein content.

Heavy metal removal from sewage sludge under citric acid and electroosmotic leaching processes

2020 ◽  
Vol 242 ◽  
pp. 116822 ◽  
Author(s):  
Degang Ma ◽  
Meizhong Su ◽  
Jingjing Qian ◽  
Qian Wang ◽  
Fanyi Meng ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Citric Acid ◽  
Sewage Sludge ◽  
Metal Removal ◽  
Heavy Metal Removal

scholarly journals Assessment of heavy metal removal efficiencies by naturally fermented and a. niger fermented pineapple wastes from contaminated sewage sludge

2007 ◽  
pp. 429-438
Author(s):  
Dominica del Mundo Dacera ◽  
Sandhya Babel
Keyword(s):  
Citric Acid ◽  
Sewage Sludge ◽  
Metal Removal ◽  
Heavy Metal Removal ◽  
Extraction Procedure ◽  
Extraction Process ◽  
Chemical Extraction ◽  
Sequential Chemical Extraction ◽  
Removal Efficiencies

Heavy metals in sewage sludge can pose a long term environmental risk due to their toxicity,non-biodegradability and consequent persistence, This study assessed the efficiencies ofvarious organic extractants such as naturally fermented and A�pergillus niger (A. niger)fermented raw liquid from pineapple wastes, in the chemical extraction process, to extract Cr,Cu, Pb, Ni and Zn, from anaerobically digested sewage sludge in Thailand. Pineapple wastesare a good source of sugar and protein and have been utilized experimentally in theproduction of citric acid by fennentation with the fungus A. niger. Comparison of theextraction efficiencies of these extractants with commercial citric acid was also investigated attwo hours leaching time and pH 3 and greater. Results of the study revealed that at pHapproaching 4, A. niger fermented liquid seemed to exhibit the best removal efficiency forpractically all metals studied, attaining as much as 72% removal for Zn, 70% for Ni, 50% forCr and 37% for Cu, although effectivity of removal seemed to be less apparent for Pb. Themost readily solubilized metal seemed to be Zn with the most removal of 92% attained bynaturally fermented raw liquid, The effectivity of removal by A. niger fem1ented liquid maybe due to the presence of citric acid and other carboxylic acids as confirmed by the HPLC andIR studies of the fem1ented liquid, Moreover, variation in metal removal efficiencies may beattributed to the fonns of metals in the sludge, as evidenced by chemical speciation studiesusing sequential chemical extraction procedure, with metals predominantly in theexchangeable and oxidizable phases showing ease of leachability,

Enhanced heavy metals removal without phosphorus loss from anaerobically digested sewage sludge

2008 ◽  
Vol 58 (1) ◽  
pp. 201-206 ◽  
Author(s):  
A. Ito ◽  
K. Takahashi ◽  
J. Aizawa ◽  
T. Umita
Keyword(s):  
Heavy Metals ◽  
Hydrogen Peroxide ◽  
Sewage Sludge ◽  
Ferric Hydroxide ◽  
Ferric Sulphate ◽  
Combined Process ◽  
Phosphorus Loss ◽  
Heavy Metals Removal ◽  
Metals Removal ◽  
Digested Sewage Sludge

Heavy metals removal without phosphorus loss from anaerobically digested sewage sludge was investigated by conducting batch experiments using hydrogen peroxide and/or iron sulphate under acidified conditions at pH 3. The addition of hydrogen peroxide to the sludge improved the elution efficiencies of As, Cd, Cu and Zn with phosphorus loss from the sludge. The optimum initial concentrations of hydrogen peroxide were. Respectively. 0.1% for As, Cd, Mn and Zn and 0.5% for Cu and Ni. The combined process of 0.1% hydrogen peroxide and 1 g Fe/L ferric sulphate enhanced the initial elution rate of Cu and Cr compared to the addition of either ferric sulphate or hydrogen peroxide, indicating that oxidants stronger than hydrogen peroxide were produced in the sludge. Furthermore, the combined process immobilised phosphorus in the sludge due to co-precipitation with ferric hydroxide or precipitation as ferric phosphate. It was concluded that there is a possibility that the combined process could remove heavy metals effectively without phosphorus loss from anaerobically digested sewage sludge.

Bacterial Leaching of Heavy Metals From Anaerobically Digested Sewage Sludge

1983 ◽  
Vol 18 (1) ◽  
pp. 151-162 ◽  
Author(s):  
L. Wong ◽  
J.G. Henry
Keyword(s):  
Heavy Metals ◽  
Sewage Sludge ◽  
Agricultural Land ◽  
Metal Removal ◽  
Health Hazard ◽  
Dry Weight ◽  
Low Grade ◽  
Bacterial Leaching ◽  
Beneficial Reuse ◽  
Digested Sewage Sludge

Abstract Spreading of sewage sludges on agricultural land is an attractive sludge management option because it combines beneficial reuse and disposal at the same time. However, it is important to reduce the metal content in the sludge in order to minimize the health hazard associated with metal uptake by plants and its subsequent accumulation in the food chain. Treatment of sludge with acid for metal removal is not practical because a large amount of acid is required. Typically 0.5 to 0.8 g of H2SO4/g dry weight of sludge will be required to achieve over 70% removal of cadmium (Cd), zinc (Zn) and nickel (Ni). Lead (Pb) and copper (Cu) are not significantly removed. A biological process called bacterial leaching, which has been used commercially for extracting copper and uranium from low grade ores, was reviewed and its potential for removing heavy metals from anaerobically digested sewage sludge was investigated. Leaching experiments were conducted and the results showed that about 80 to 90% removal of cadmium, zinc and nickel, and 60 to 70% removal of copper were possible. The acid requirement was significantly reduced because only 0.15 g of H2SO4/g dry weight of sludge was needed.

Enhancing Efficiency of Full-Scale Ultrafiltration Membrane Treatment for Increased Capacity and Lower Operating Costs

2010 ◽  
Vol 5 (4) ◽  
Author(s):  
M.C. White PE ◽  
M.J. Kosterman
Keyword(s):  
Citric Acid ◽  
Water Treatment ◽  
Operating Costs ◽  
Percent Reduction ◽  
Chemical Cleaning ◽  
Optimization Program ◽  
Systematic Optimization ◽  
Percent Increase ◽  
Treatment Facilities ◽  
Membrane Treatment

At time of commissioning, the Racine, Wisconsin, USA ultrafiltration (UF) membrane treatment system fail short of meeting its operational goals concerning capacity and chemical cleaning intervals. The systematic optimization of this 189-million-litre-per-day (MLD) capacity UF system provided tangible operational benefits, which included a 30-percent reduction in power use, a 50-percent reduction in chlorine chemical use, a 36-percent reduction in citric acid use and a simultaneous 7-percent increase in net treatment capacity of the system. In addition, the optimization program reduced the level of buildup of foulants on the surface of the membranes. This paper summarizes the optimization procedures followed at Racine, discussing how similar measures may be applicable to other water treatment facilities.

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