**15. Application of biosorption for real wastewaters/effluents**

Efforts have been devoted to apply the process of biosorption as a waste treatment method. Instead of aqueous metal solutions, the experiments involved the effluents collected from various polluted sources. Various studies have reported high removal efficiencies.

However, the removal efficiency attained with real effluents may be comparable with single

Application of Biosorption for Removal of Heavy Metals from Wastewater

http://dx.doi.org/10.5772/intechopen.77315

95

Gooseberry fruit (*Emblica officinalis*) waste was used as the biosorbent for the removal of Cu from the real electroplating wastewater (50 ml), containing various metals including Cu, from the local electroplating plant in Aligarh city. The wastewater (pH 3.0) was freed of suspended matter, diluted 10 times to the final concentration of Cu (II) of 38 mg and the pH was then adjusted to pH 4.2 before biosorption. The efficiency of metal removal was 98.07% in the column process (1 ml/min) and 65% in batch experiments. The removal efficiency (as calculated from the data given) for mono-metallic solution batch experiments was comparable [215].

In another study, wastewater having heavy metals and textile dyes was collected from the local metal, and the textile processing industry in Turkey was treated with *Punica granatum* L. peels. Under optimum experimental conditions the removal of Pb (II) was 98.07%. Simulated water containing interfering ions also showed a removal efficiency of 98.18%. This was compared well with removal efficiencies (94% as calculated from the data) with mono-metal solutions under optimal conditions. Thus, other components of wastewater such as different

The effluent discharged from the battery industries located in the Northern region of Kolkata was treated by *Aspergillus versicolor* biomass to remove Pb (II) ions. It was observed that the efficiency for the removal of Pb (II) ions was found to be 86% which was almost similar to the value obtained by the mono-metallic synthetic system. Hence the study suggests that the presence of additional cations or anions present in the effluent does not affect the biosorption

Modification to the process conditions with real wastewaters may be necessary to achieve

A *Spirogyra* granule packed column was employed for treating various industrial effluents which was done by passing wastewaters (1 L, 0.6 ml/min) from different industries namely the carpet industry, paper mill industry, and electroplating industry near Varanasi, India. The packed column achieved removal efficiency of >90% for Cu, Cd, Zn, Ni, Pb, and Cr from the three industrial wastewaters. However, this required the reduction of pH from 7.8 to 4.5 (for metals other than

Neem sawdust was employed as the biosorbent in a column bioreactor for the removal of Cr (VI) at 94 mg/L from 1.5 L of raw tannery wastewater collected from a common effluent treatment plant in India. The results revealed that the biosorbent of 20 g was sufficient for the removal of chromium with the removal efficiency of 99%. Batch experiments were conducted

In spite of the advantages over other conventional techniques, there is a glaring lack of adoption of biosorption as a waste treatment technology. Few commercial ventures offering

Cr) and 2 (for Cr) although the optimum pH of 5.0 was used with metal solutions [218].

at 2 g/L dosage at initial concentrations of 150 mg/L in 100 ml shake flasks [219].

**16. Commercialization and adoption of biosorption as waste** 

removal efficiencies comparable to those obtained with mono-metal solutions.

or simulated synthetic metal solutions.

metallic salts and dyes did not interfere with removal [216].

efficiency of the biomass used in the experiment [217].

**treatment technology**

The electroplating waste containing Cu (II), (6 mg/L) along with other ions (Zn, Cr (VI), Na, Ca, K), was treated with different agro-waste/natural biosorbents at the optimum conditions (pH −6.0, determined by batch experiments). Removal efficiency for Cu ranged from 77 to 95%. Other metals in the effluents were also removed to various extents [211].

Industrial effluent samples were collected from El-Fayoum for chemical production company outfalls in Egypt to decontaminate Co (II), Cd (II), Cr (III), and Pb (II) by using four red seaweeds namely *Corallina mediterranea, Galaxaura oblongata, Jania rubens* and *Pterocladia capillacea*. The biosorption efficiencies of the four biomasses were within the range from 57 to 94% and the highest efficiency was observed with *Galaxaura oblongata* biomass followed by *Corallina mediterranea, Pterocladia capillacea* and *Jania rubens* with mean biosorption efficiencies of 84, 80, 76, and 72%, respectively. The study demonstrates that the four seaweeds can be promising, cheap, efficient, and biodegradable biosorbents for lowering of metal ion pollution from the environment [212].

In related study, the efficacy of sugarcane bagasse (the immobilized and native form) for the removal of chromium from wastewater collected from the local tanning plant (Kasur, Pakistan) was evaluated. At a biosorbent dose of 0.1 g and pH of 2.0, the biosorption efficiency was found to be 411 mg/g of biomass which is equivalent to 73% of total chromium present in the wastewater. This highest efficiency was observed with the immobilized form of the biomass when compared with the other forms (native and chemically treated). At the batch level, the maximum uptake was 80.6 and 41.5% in batch mode for Cr (VI) and Cr (III) [213].

The removal efficiency with real effluents can be affected due to the presence of other components like other metals, organic matter, anions, and so on which can compete for the binding sites. The fungal biosorbent *Pleurotus ostreatus* was used for the treatment of wastewater collected from the main drain of the local electroplating industrial units situated at Shahdra, Lahore, Pakistan. A slight wane in the biosorption efficiency when the biomass was used for real wastewater treatment was observed. In case of a real effluent, the metal removal efficiencies for Cu (II), Ni (II), Zn (II), and Cr (VI) were 46.01, 59.22, 9.1, and 9.4%, respectively, while for the single synthetic metal solution, it was 52, 63.52, 10.9, and 11.8%, respectively. This moderate to slight decrease in the removal efficiency of biosorbent might be due to the competition of various contaminants for binding sites as reported in many other studies. Another compounding factor is high COD which also causes reduction in biosorption [121].

The potential of seaweed (*Sargassum)* biomass was used to decontaminate heavy metal ions from urban real storm water runoff. The biosorbent was able to remove metal ions but the efficiency was slightly lesser (90, 65, 50, and 40%) than the single synthetic solute system (80, 50, 15, and 10%) of Pb, Cu, Zn, and Mn, respectively, under similar conditions. The other contaminants like anions, organics, and other trace metals present in the runoff may compete with the existing binding sites of the biosorbent resulting in a decrease in the efficiency of biosorption [214].

However, the removal efficiency attained with real effluents may be comparable with single or simulated synthetic metal solutions.

**15. Application of biosorption for real wastewaters/effluents**

als in the effluents were also removed to various extents [211].

environment [212].

94 Biosorption

various polluted sources. Various studies have reported high removal efficiencies.

Efforts have been devoted to apply the process of biosorption as a waste treatment method. Instead of aqueous metal solutions, the experiments involved the effluents collected from

The electroplating waste containing Cu (II), (6 mg/L) along with other ions (Zn, Cr (VI), Na, Ca, K), was treated with different agro-waste/natural biosorbents at the optimum conditions (pH −6.0, determined by batch experiments). Removal efficiency for Cu ranged from 77 to 95%. Other met-

Industrial effluent samples were collected from El-Fayoum for chemical production company outfalls in Egypt to decontaminate Co (II), Cd (II), Cr (III), and Pb (II) by using four red seaweeds namely *Corallina mediterranea, Galaxaura oblongata, Jania rubens* and *Pterocladia capillacea*. The biosorption efficiencies of the four biomasses were within the range from 57 to 94% and the highest efficiency was observed with *Galaxaura oblongata* biomass followed by *Corallina mediterranea, Pterocladia capillacea* and *Jania rubens* with mean biosorption efficiencies of 84, 80, 76, and 72%, respectively. The study demonstrates that the four seaweeds can be promising, cheap, efficient, and biodegradable biosorbents for lowering of metal ion pollution from the

In related study, the efficacy of sugarcane bagasse (the immobilized and native form) for the removal of chromium from wastewater collected from the local tanning plant (Kasur, Pakistan) was evaluated. At a biosorbent dose of 0.1 g and pH of 2.0, the biosorption efficiency was found to be 411 mg/g of biomass which is equivalent to 73% of total chromium present in the wastewater. This highest efficiency was observed with the immobilized form of the biomass when compared with the other forms (native and chemically treated). At the batch level, the maximum uptake was 80.6 and 41.5% in batch mode for Cr (VI) and Cr (III) [213]. The removal efficiency with real effluents can be affected due to the presence of other components like other metals, organic matter, anions, and so on which can compete for the binding sites. The fungal biosorbent *Pleurotus ostreatus* was used for the treatment of wastewater collected from the main drain of the local electroplating industrial units situated at Shahdra, Lahore, Pakistan. A slight wane in the biosorption efficiency when the biomass was used for real wastewater treatment was observed. In case of a real effluent, the metal removal efficiencies for Cu (II), Ni (II), Zn (II), and Cr (VI) were 46.01, 59.22, 9.1, and 9.4%, respectively, while for the single synthetic metal solution, it was 52, 63.52, 10.9, and 11.8%, respectively. This moderate to slight decrease in the removal efficiency of biosorbent might be due to the competition of various contaminants for binding sites as reported in many other studies. Another

compounding factor is high COD which also causes reduction in biosorption [121].

The potential of seaweed (*Sargassum)* biomass was used to decontaminate heavy metal ions from urban real storm water runoff. The biosorbent was able to remove metal ions but the efficiency was slightly lesser (90, 65, 50, and 40%) than the single synthetic solute system (80, 50, 15, and 10%) of Pb, Cu, Zn, and Mn, respectively, under similar conditions. The other contaminants like anions, organics, and other trace metals present in the runoff may compete with the existing binding sites of the biosorbent resulting in a decrease in the efficiency of biosorption [214].

Gooseberry fruit (*Emblica officinalis*) waste was used as the biosorbent for the removal of Cu from the real electroplating wastewater (50 ml), containing various metals including Cu, from the local electroplating plant in Aligarh city. The wastewater (pH 3.0) was freed of suspended matter, diluted 10 times to the final concentration of Cu (II) of 38 mg and the pH was then adjusted to pH 4.2 before biosorption. The efficiency of metal removal was 98.07% in the column process (1 ml/min) and 65% in batch experiments. The removal efficiency (as calculated from the data given) for mono-metallic solution batch experiments was comparable [215].

In another study, wastewater having heavy metals and textile dyes was collected from the local metal, and the textile processing industry in Turkey was treated with *Punica granatum* L. peels. Under optimum experimental conditions the removal of Pb (II) was 98.07%. Simulated water containing interfering ions also showed a removal efficiency of 98.18%. This was compared well with removal efficiencies (94% as calculated from the data) with mono-metal solutions under optimal conditions. Thus, other components of wastewater such as different metallic salts and dyes did not interfere with removal [216].

The effluent discharged from the battery industries located in the Northern region of Kolkata was treated by *Aspergillus versicolor* biomass to remove Pb (II) ions. It was observed that the efficiency for the removal of Pb (II) ions was found to be 86% which was almost similar to the value obtained by the mono-metallic synthetic system. Hence the study suggests that the presence of additional cations or anions present in the effluent does not affect the biosorption efficiency of the biomass used in the experiment [217].

Modification to the process conditions with real wastewaters may be necessary to achieve removal efficiencies comparable to those obtained with mono-metal solutions.

A *Spirogyra* granule packed column was employed for treating various industrial effluents which was done by passing wastewaters (1 L, 0.6 ml/min) from different industries namely the carpet industry, paper mill industry, and electroplating industry near Varanasi, India. The packed column achieved removal efficiency of >90% for Cu, Cd, Zn, Ni, Pb, and Cr from the three industrial wastewaters. However, this required the reduction of pH from 7.8 to 4.5 (for metals other than Cr) and 2 (for Cr) although the optimum pH of 5.0 was used with metal solutions [218].

Neem sawdust was employed as the biosorbent in a column bioreactor for the removal of Cr (VI) at 94 mg/L from 1.5 L of raw tannery wastewater collected from a common effluent treatment plant in India. The results revealed that the biosorbent of 20 g was sufficient for the removal of chromium with the removal efficiency of 99%. Batch experiments were conducted at 2 g/L dosage at initial concentrations of 150 mg/L in 100 ml shake flasks [219].
