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Open Access Journal of Waste Management & Xenobiotics Research Article 30 min read

Advanced Techniques for Wastewater Treatment: A Review

Kunal, Rajput S and Yadav S*
* Corresponding author
ISSN: 2640-2718  10.23880/oajwx-16000126  Received: July 24, 2019  Published: August 28, 2019
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Keywords
Wastewater Treatment Membrane Filtration Heavy Metals Removal
Abstract

Freshwater in lake and pond are often found to be polluted by heavy metals such as As, Zn, or Pb which are toxic in nature and non-biodegradable. Heavy metals are readily consumed by both aquatic flora and fauna present in the freshwater environment. It also polluted the air, water, and soil. Thus, they have adverse impact on the entire ecosystem. These heavy metals also enter the human systems through food consumed. This review discusses the methods and their mechanism used to reduce the amount of such heavy metals The methods which are in practice are Electrochemical Treatment (Electrocoagulation, Electro-Floatation, and Electro-Deposition), Physicochemical Process (Chemical Precipitation, Ion-Exchange, and Adsorption), Membrane Filtration (Nanofiltration, Reverse Osmosis, Microfiltration, Ultrafiltration, and Electro-Dialysis),and Photo-Catalysis and Nanotechnology Treatment.

Introduction

Fresh clean water is a necessity for all living organisms and often there is scarcity due to draughts, industrialization, and growing population. The treated wastewater can be used to fill this scarcity by treating them through certain processes in order to eliminate the toxic heavy metals as well as other pollutants to make it safe for domestic or industrial reuse. Some of the common toxic heavy metals present in waste water are Co, Cu, Ni, As, Cr, Pb, Zn and Hg [1, 2, 3]. In higher concentration, heavy metals are fatal when consumed by humans through foods and drinks. In fact, water is the apex origin of all diseases caused by pathogens [4, 5, 6]. There are many treatments available to purify the wastewater from its toxic elements but the most preferred are the ones which are Economical, Environment friendly, and feature no alternative pollutants. The two main types of methods for treatment include biological methods and physical/chemical methods; however, biological methods are not as applicable as chemical method for eliminating heavy metals. This article will discuss the physical and chemical treatment methods for eliminating heavy metals from wastewater as well as analyze their procedures, applications, advantages, and disadvantages.

Current Methods for Treating Wastewater

The different options for eliminating heavy metals effectively are Electrochemical Treatment (electrocoagulation, electroflotation, and electro- deposition), Physicochemical Process (chemical precipitation, ion-exchange, and adsorption), Membrane Filtration (nanofiltration, reverse osmosis, microfiltration and ultrafiltration, and electro-dialysis), Photo-Catalysis and Nanotechnology Treatment. The methods, their limitations, and scope for their improvement are discussed below.

**Electrochemical Treatment**

Electrochemical treatments are the least studied methods as they are the most expensive ones. However, electrochemical treatment offers better efficiency and required less space than all other treatments [7, 8, 9, 10]. The electrochemical treatments to be known are Electrocoagulation (EC), Electroflotation (EF), and Electro-Deposition (ED).

Electro-Floatation (EF): Recently Electroflotation (EF) method has gained attraction in wastewater treatment to remove heavy metal pollutants as the other methods were not as efficient with dilute solutions [11, 12, 13]. EF was used for the first time in 1904 to remove mineral ores. It gained widespread usage due to its adaptability, low expense, and ease of operation. EF is currently used in the industries such as food processing for wastewater treatment [14]. EF dissociates pollutants by floating them to the top of the liquid and all this occur in 3 phases. First, the pollutants were drawn to a cell that has 2 electrodes and a power supply. The reaction for this phase is:

The heavy metals stick to O₂ and H₂ molecules and are destabilized to form flocs. The second step is the separation by settling or flotation of generated foam and settled flocs. The third step is removing collected pollutants by filtration method. Pollutant removal efficiency depends upon the size of the bubbles created during electrolysis. The energy consumed depends on the cell design, electrode materials, and operating conditions. It is common practice in wastewater treatment to combine EC and EF in order to decrease the limitations mentioned above. Combining the two method leads to higher efficiency than using them isolated [15].

Electrocoagulation (EC): EC is a straightforward method that is generally considered unreliable; however, due to improved technology, many pollutants are now eliminated with this method [16, 17, 18, 19]. EC works by supplying low electric current to the wastewater and thereby the electrical charge keeps the heavy metals together are negative charged and the metals are coagulated from the aqueous phase to come together in the mass (called the sludge or floc). The floc developed by EC is more stable, larger, and can be easily taken out by normal physical filtration system [20, 21, 22]. EC is usually conducted with Al or Fe electrodes. The main reaction for Al electrodes is:

$$Al^{3+} + 3OH^- \quad Al(OH)_3$$

The Al(OH)₃ formed becomes a substance that can trap the heavy metal ions and separated them from the rest. Experimental results indicated as an optimum removal efficiency of 98.2% was achieved by using the Al anode at current density of 0.2 Adm⁻². Previous studies had demonstrated the removal efficiency of 97.2% with current density of 0.5 Adm⁻² and pH value 7 using 2 mg/l of Mg [23, 24]. In an earlier study, 30 iron and stainless-steel rods of 50 mm length and 5 mm diameter were utilized. Results from this experiment indicated that at the current densities of 6 and 8 mAcm⁻³ the Pb amount is reduced by 96.7% and 95.2% respectively. These results demonstrate that how removal efficiency is directly proportional to the current density used as a result of increase in the rate of formation of hydroxide and steel flocs [25]. EC is also an ecofriendly method for removing waste since it utilizes electrons instead of adding additional chemicals. However, EC cannot remove particles that are infinitely soluble.

Electro deposition (ED): Electro-deposition (ED) is a convenient and economical method for removing the heavy metals present in wastewater. This method is better because no other reagents are needed, and no sludge is formed during the whole process. ED works by changing dissolved metal ions from liquid state to solid state by depositing on ionic conductor in order to protect them from decay. ED reduces and oxidizes the heavy metal ions in a single step in a cell that includes one anode, one cathode, one electrolyte cell, and a current source [15, 26, 27, 28, 29, 30, 31]. The metal reduced, and electroplated on the cathode. The ultimate size of electrodeposite depends upon the nucleation of deposits, and their growth. Anodes must be insoluble in water in order to avoid disrupting the process. Competing reactions do occur during the process; which includes hydrogen turning into a gaseous state.

The productivity of the ED method depends upon the heavy metal's concentration in the initial waste product solution, temperature, pH level, and the presence of any complex and chelating agents [26, 27]. This method is of great advantage due to its ability to be used with non-aqueous solutions or those containing chelating agents. ED can be used with aqueous solution as well and it often contains chelating agents such as EDTA, NTA, and citrate [32, 33, 34]. Chelating agents are very helpful since they bind with heavy metal cations to decrease the formation of insoluble salts thereby improving removal efficiency very effectively.

**Physicochemical Processes**

Ion-Exchange: The ion-exchange method was established on a reversible interchange of ions between solid and liquid state. The process starts with ion-exchange reaction followed by the physical absorption of heavy metal ions, which produces the complex by the counter-ion and the functional group. Finally, hydration occurs at the surface of the solution or pores of the adsorbent. The ion exchange method is affected by numerous variables including: pH, anion concentration, temperature, initial concentration of adsorbent and sorbate, and the contact time [35, 36, 37, 38]. This technique utilizes a resin which removes the ions from the electrolytic solution to release other ions with similar electrical charges. During the metal ions capture, the following interaction occurs:

$$nRSO_3^- - H^+ + Mn^+ \rightarrow nRSO_3^- - Mn^+ + nH^+$$

$n$ is a constant connected to the oxidation state of metal ions. Ion-exchange method is more preferred to methods such as chemical precipitation as it offers many advantages like limited cost, high metal recovery levels, high selectivity, and increased efficiency. The resins that are favored for the use in ion-exchange processes are synthetic polymers such as styrene-divinyl-benzene or other gel options such as macropore. Gel option offers the benefit on cost efficiency and stability [35, 39, 40, 41].

Adsorption: Adsorption is a common technique to remove heavy metals from wastewater that has had significant result in reducing the amount of heavy metals. Adsorption is a transfer between the liquid phase and solid phase (adsorbent). Adsorption comprises of three stages 42-45]. First, the pollutant is penetrated from the bulk solution onto the adsorbent surface. Then, the pollutant is adsorbed on the adsorbent surface. Lastly, the penetration in the adsorbent structure. Adsorbent provides a high surface area and high adsorption ability. Adsorbents can easily be found in agricultural waste, industrial by-products, or other materials found in nature. Commonly used adsorbents include activated carbon, carbon nanotubes, and [44].

Activated Carbon

When potassium carbonate (K$_2$CO$_3$) is used, the activated carbon (AC) is produced from agricultural by-products. Their surface area ranges from 1266-3256 m$^2$g$^{-1}$. AC is commonly used for adsorption methods to take out the toxic metal from wastewater [43, 46, 47]. Previous research indicates that activated carbon prepared at 900 $^\circ$C is highly efficient at eliminating Ni from a liquid solution with an adsorbent concentration of 0.25g. pH values may also affect adsorption method and adsorption is best when the pH level is between 2 and 5 [43, 48, 49].

Carbon Nanotubes

Carbon nanotubes (CNTs) are known for having properties which make absorbent extremely effective in taking out heavy metals from wastewater [50, 51, 52]. However, CNTs are immobilized by calcium alginate to limit the risks created when CNTs are discharged into water. Previous studies show that a pH of 5 is optimal for using CNTs to eliminate heavy metals.

Wood Sawdust

Wood sawdust is a waste product that is produced after mechanical wood processing in plant and can be utilized as a cheap adsorbent for heavy metals removal. Sawdust can be used due to its lignocellulosic composition. Sawdust is made up of cellulose and lignin which both display the ability to bind metal cations. Recently, this interest has arisen to search for more environment friendly techniques to eliminate heavy metals from wastewater and sawdust is one such good option [53, 54]. In addition, modified cotton, waste wool, tree barks, and nuts waste are all good alternatives for heavy metals adsorption. Previous studies have shown that sawdust is more effective in removing Cu, Zn, and Cd through adsorption method [55, 56, 57].

Chemical Precipitation: Chemical precipitation is a straightforward and an easy treatment method for removing heavy metals from wastewater [58, 59, 60]. Chemical precipitation requires a significant amount of chemicals in order to decrease heavy metal ions to an adequate limit for safe disposal. However, it may fail to reach that point and chemicals added may themselves pose a pollution threat. In this process, chemical agents react with metal ions and transform them into insoluble particles. The solid phase is then separated from the solution by sedimentation or filtration. pH is significant to this process with basic condition (pH=11) favored to improve the removal of heavy metals. After creating the ideal pH levels, the soluble metal ions are transformed to the dissolved solid by reacting with a precipitant agent [61].

Sulfide Precipitation

Sulfide precipitation is similar to hydroxide precipitation, since both soluble and insoluble can be used to precipitate metal ions. Sulfide is utilized to precipitate the heavy metal ions as metal sulfides and the resultant sludge formed can be taken out of the solution by gravity settling or filtration [38, 62, 63]. Sulfide precipitation requires pre& post treatment, and proper control of reagent additions because of the toxicity of the sulfide ions and H$_2$S. The precipitation methods are performed by adjusting the composition and other parameters so that the ionic elements of the metals can be removed by differentiated from a soluble phase to a solid phase [64, 65, 66]. Heavy metal ions generally precipitate in the form of hydroxide:

$$M^{2+} + 2OH^- \quad M(OH)_2$$

$M^{2+}$ and OH$^-$ are the metal ions and the precipitant respectively. The ones most often utilized are lime (CaO) and Ca(OH)$_2$, both are commonly available. CaO requires a significant dosage as well as offers low metal removal efficiency due to inadequate settling and dissolution of precipitates. Past research indicates that sulfide precipitation was successful in eliminating Cu, Zn, Cr, and Pb from wastewater [65, 67, 68].

• Hydroxide Precipitation
Hydroxide precipitation integrates coagulant such as iron salts, alum, and polymers that may improve the heavy metal separation from wastewater. Soluble metals can be precipitated as hydroxide by using filtration or sedimentation process. Alkaline agents can be used to increase the pH of the wastewater. Alkaline agents reduce the solubility of metal ions and precipitate out from the solvent [37, 38, 41, 69]. The reaction for hydroxide precipitation is:

$$M^{2+} + OH^- + nR^- \quad M(R)_n(OH)^+$$

Membrane Filtration Process

Membrane Filtration process was developed during the 1970s and 1980s in order to increase efficiency with no pollution and less energy consumption than the other prevailing methods of that time period. Membrane filtration process is highly utilized for removing heavy metals from wastewater due to its simplicity of the method [70, 71, 72]. The procedure starts with a separation occurring through a semipermeable membrane. There are many different membranes used and they vary in terms of type of nature, fabrication, and structure. In practice, three different types of membranes are used for separation processes. These membranes can be called as liquid, pressure driven, and hybrid membranes. A membrane is defined as a layer with a porous or nonporous structure that is used to produce contact between two homogenous phases in order to separate pollutants of different sizes. Membrane performance can be affected by materials used, its pore size, and composition. Materials should be selected more judiciously as it helps to produce membranes with more chemical resistance and less structural imperfections. The different materials, typically used to produce membranes are metallic, ceramic, composite, nano based, reactive or catalytic, and biologically modified materials [73, 74, 75, 76]. Composite materials like polymers, Polymers are often selected for membrane production due to their porous structures and affordability. Polymers can be used with many filtration processes including microfiltration and reverse osmosis. Polymer membrane materials are cellulose acetate, polyvinylidene fluoride, polyacrylonitrile, polypropylene, polyethersulfone, and polysulfone. Ceramic materials are often optimal and better than polymer materials due to their narrow pore size and high mechanic, thermal, and chemical stability [70, 77, 78, 79]. Ceramic membranes are formed out of alumina, zirconia, silica, titania, oxide mixtures, and sintered metals. The different methods of membrane filtration are nanofiltration, reverse osmosis, microfiltration and ultrafiltration, and electro-dialysis.

Nano filtration: Nanofiltration (NF) is a recent technology and was developed to make separation of large molecules using small spores possible. NF is environment friendly and energy efficient and is often used to remove pollutants found in groundwater, surface water, and wastewater. This process is referred to as a liquid phase filtration since it separates a large range of organic and inorganic particles from their [80, 81, 82]. The separation is dependent upon the molecular weight cut off. NF requires a three-step procedure: pretreatment, treatment, and post treatment. Firstly, the water needs to be treated before going into the system in order to reduce more pollution. This step includes pre filtration, coagulation, adsorption, ion exchange, and chemical conditioning. Secondly, the actual membrane separation process occurs and finally the post treatment is carried out. NF is successful in eliminating heavy metals found in water especially in cleaning water contaminated by strong pollutants such as Pb and Cd [75, 83, 84, 85].

Microfiltration and Ultrafiltration: Microfiltration (MF) and Ultrafiltration (UF) are one topic as mentioned due to their many similarities. Both MF and UF are pressure driven with a shared area of usage and are based on molecular sieving with porous membranes. Both have remarkably similar separation procedure. However the key difference between MF and UF, is that the solutes eliminated by MF are bigger than those eliminated by UF [86, 87, 88]. Both MF and UF have wide applications such as water purification, removing particles, and clarifying different solutions. The toughest part of a MF and UF method is selecting the appropriate membrane unless this may lead to have an impact on the efficiency of heavy metals removal. Membranes vary accordingly to their porosity, structure, and material [80, 89, 90]. UF and MF both use membrane that must be porous; however, membranes can be symmetric or asymmetric. Symmetric membranes are characterized by structures which do not change over the membrane cross section. MF membranes are usually symmetric while UF membranes are typically asymmetric. Hydrophilic membranes, hydrophobic membranes and crystalline polymers are commonly used as MF and UF membranes [91, 92]. The two filtration methods are dead-end and cross-flow methods. Dead end is used when feed flow perpendicular to the membrane surface while cross-flow method is used when the flow is parallel. Cross-flow requires more complex utilities; however, it does result in higher flux rates and membrane lifetimes. Electro dialysis: Electrodialysis (ED) research and developement starts during the 1950s. ED is a helpful method for removing pollutants and is now used by many industries. ED works by an ion selective exchange membrane (IEMs). IEMs do not transport cations and anions at the same time; however, the ion transportation occurs only due to electrical potential or the concentration gradient [93, 94, 95]. If the ED electrodes polarity is reversed, then the method is referred to as electrodialysis reversal (EDR) which may be preferred over ED. EDR has a larger water recovery rate than ED but requires more plumbing and electrical controls. Reverse Osmosis: Reverse Osmosis (RO) was initially researched in the 1920s; however, it did not become widely used until around the 1950s. RO is used by a variety of industries including food, biotechnology, pharmaceuticals, and water processing. RO is a pressure driven membrane technique. RO operates under hydraulic operating pressure and utilizes a semipermeable membrane with no distinct pores in order for the particles to flow through. Therefore, the transition must occur by diffusion [96, 97, 98, 99, 100]. For RO to occur first the water from a concentrated solution of heavy metal ions absorbs onto the surface of the membrane. Next, the particles diffuse through the membrane due to a concentration gradient. After the separation is complete there is a concentrated heavy metal solution one side and a treated solution on the other side.

Nanotechnology

Nanotechnology is commonly used for treating wastewater because to its large surface area and high adsorption efficiency. However, the use of nanotechnology also increases the chance of nano- pollutants being released into the environment. Nanotechnology has been the main focus of many researchers due to its pervasive use in chemistry, biology, medicine, and marketing products [101]. There are two methods used for removing heavy metals from wastewater by nanotechnology which are in- situ and ex- situ. In-situ is used if the wastewater is being treated in a place of contamination. Ex-situ is used for the treatment done after transferring wastewater to a preferred area. In-situ treatments are favored over ex-situ due to higher removal rates and economic benefit 102-104]. The three different types of nanoparticles used are adsorptive, reactive, and hybrid magnetic particles. Nano magnetic oxides (NMOs) are adsorptive and used often due to their high surface area, stability, and mesoporous shape. Nano zero-valent iron (nZVI) is a nanoparticle used to clean the wastewater and remove heavy metals through reactive technologies [104, 105]. In-situ use of nZVI starts with injecting it into the wastewater solution thereby increasing the pH and thus reducing the redox potential. The final type of nanoparticles is hybrid magnetic nanoparticles (MNP’s) which include two or more nanometer components upon which one of them is magnetic. MNP’s are used because of their low toxicity, cost efficiency, ease, and high removal rates. Many materials can be applied to coat the MNP’s including polymers. Past research has shown that different kinds of MNP’s can be used to remove heavy metal in an efficient and economical manner [106, 107].

Photo catalysis Process

Photocatalysis is a type of advanced oxidation process that used as recent advance technology for air and water purification. This technique uses non-toxic semiconductors and light with an appropriate wavelength as opposed to a chemical compound. This technique favored over chemical processes due to the absence of toxic materials, simplicity, affordability, increased stability, and increased efficiency [108, 109]. Photocatalytic systems consist of five steps to separate the pollutants. First, the pollutants are transferred to the surface. Next, the pollutants are absorbed by the semiconductors. Thirdly, the photocatalytic reactions occur. Fourthly, the products are decomposed. Finally, the decomposed products are taken out of the area [110]. The third step is the vital step for the succession of reaction. This method required light to act as an activator which made thermal activation unnecessary. The first step also includes a photon excitation in the semiconductors. When a visible light with energy equal or more than the energy of the semiconductor excitation is used, the valence electrons get elevated to the conduction band [109]. This creates an electron hole pair so the light absorption process can take place. While this is occurring, the pollutants are reduced and oxidized by the transferring of photo holes and photoelectrons.

After the transformation is completed, heavy metals are recovered by mechanical and thermal procedures. Common semiconductors used in photocatalysis are oxides such as TiO2, ZnO2, CeO2, WO2, and sulfides such as CdS, ZnS, WS2 [111, 112, 113]. Limitation to this method includes recombination of electron or hole, unwanted by- products formed, and errors in visible light absorption.

Conclusions

Heavy metals are detrimental to both environment as well as human beings. These metals are often found in wastewater and must be removed. This paper discusses the most common methods which are currently used to clean wastewater. The methods discussed are Electrochemical, Physicochemical, Membrane Filtration, Photocatalytic, and Nanotechnology. Each treatment has its own advantages, limitations and removal efficiencies under different specific circumstances. However, despite unique optimal conditions for each treatment, these are all found to be an effective way of removing heavy metals, pollutants from wastewater.

References

  1. DWAF (1996) South African Water Quality Guidelines Volume 1 Domestic Use.
  2. Environmental Protection Agency I (1997) Wastewater Treatment Manuals. Management.
  3. Nnorom IC, Osibanjo O (2008) Overview of electronic waste (e-waste) management practices and legislations, and their poor applications in the developing countries. Resour Conserv Recycl 52(6): 843-858.
  4. Gordon B, Callan P, Vickers C (2008) WHO guidelines for drinking-water quality. WHO Chron 38: 564.
  5. Zheng L, Wu K, Li Y, Qi Z, Han D, et al. (2008) Blood lead and cadmium levels and relevant factors among children from an e-waste recycling town in China. Environ Res 108(1): 15-20.
  6. Chiang YW, Santos RM, Monballiu A, Ghyselbrecht K, Martens JA, et al. (2013) Effects of bioleaching on the chemical, mineralogical and morphological properties of natural and waste-derived alkaline materials. Miner Eng 48:116-125.
  7. Feng C, Suzuki K, Zhao S, Zhao S, Sugiura N, et al. (2004) Water disinfection by electrochemical treatment. Bioresour Technol 94(1): 21-25.
  8. Dimitrijevic SB, Dimitrijevic SP, Vukovic MD (2013) Modern Water Treatment By Electrochemical Oxidation -a Review. Tmt pp: 10-11.
  9. Cong VH, Sakakibara Y, Komori M, Kishimoto N, Watanabe T, et al. (2016) Recent Developments in Electrochemical Technology for Water and Wastewater Treatments. J Water Environ Technol 14: 25-36.
  10. Hernandez CMA, May A, Bonakdapour A, Mohseni M, Wilkinson DW (2017) Analytical quantification of electrochemical ferrates for drinking water treatments. Can J Chem 95(1): 105-112.
  11. Kushwaha JP, Srivastava VC, Mall ID (2010) Organics removal from dairy wastewater by electrochemical treatment and residue disposal. Sep Purif Technol 76(2):198-205.
  12. Ngamlerdpokin K, Kumjadpai S, Chatanon P, Tungmanee U, Chuenchuanchom S, et al. (2011) Remediation of biodiesel wastewater by chemical- and electro-coagulation: A comparative study. J Environ Manage 92(10): 2454-2460.
  13. Nidheesh PV, Gandhimathi R (2012) Trends in electro-Fenton process for water and wastewater treatment: An overview. Desalination 299: 1-15.
  14. Azimi A, Azari A, Rezakazemi M, Ansarpour M (2017) Removal of Heavy Metals from Industrial Wastewaters: A Review. ChemBioEng Rev 4(1): 37- 59.
  15. Chen G (2004) Electrochemical technologies in wastewater treatment. Sep Purif Technol 38(1): 11- 41.
  16. Vik EA, Carlson DA, Eikum AS, Gjessing ET (1984) Electrocoagulation of potable water. Water Res 18(11): 1355-1360.
  17. Koparal AS, Outveren UB (2002) Removal of nitrate from water by electroreduction and electrocoagulation. J Hazard Mater 89(1): 83-94.
  18. Holt PK, Barton GW, Mitchell CA (2005) The future for electrocoagulation as a localised water treatment technology. Chemosphere 59(3): 355-367.
  19. Hakizimana JN, Gourich B, Chafi M, Stiriba Y, Vial C, et al. (2017) Electrocoagulation process in water treatment: A review of electrocoagulation modeling approaches. Desalination 404: 1-21.
  20. Isa MH, Ezechi EH, Ahmed Z, Magram SF, Kutty SRM (2014) Boron removal by electrocoagulation and recovery. Water Res 51 (15): 113–123.
  21. An C, Huang G, Yao Y, Zhao S (2017) Emerging usage of electrocoagulation technology for oil removal from wastewater: A review. Sci Total Environ 579: 537- 556.
  22. Hu C, Sun J, Wang S, Liu R, Liu H, et al. (2017) Enhanced efficiency in HA removal by electrocoagulation through optimizing flocs properties: Role of current density and pH. Sep Purif Technol 175: 248-254.
  23. Vasudevan S, Lakshmi J, Sozhan G (2011a) Optimization of electrocoagulation process for the simultaneous removal of mercury, lead, and nickel from contaminated water. Environ Sci Pollut Res Int 19(7): 2734-2744.
  24. Vasudevan S, Lakshmi J, Sozhan G (2011b) Studies on the Al-Zn-In-alloy as anode material for the removal of chromium from drinking water in electrocoagulation process. Desalination 275(1-3): 260-268.
  25. Mansoorian HJ, Mahvi AH, Jafari AJ (2014) Removal of lead and zinc from battery industry wastewater using electrocoagulation process: Influence of direct and alternating current by using iron and stainless steel rod electrodes. Sep Purif Technol 135: 165-175.
  26. Scott K, Paton EM (1993a) An analysis of metal recovery by electrodeposition from mixed metal ion solutions-part I. Theoretical behaviour of batch recycle operation. Electrochim Acta 38(15): 2181- 2189.
  27. Scott K, Paton EM (1993b) An analysis of metal recovery by electrodeposition from mixed metal ion solutions-part II. Electrodeposition of cadmium from process solutions. Electrochim Acta 38(15): 2191- 2197.
  28. Metcalf E, Eddy H (2003) Wastewater engineering: treatment and reuse.
  29. Von SM (2008) Wastewater characteristics, treatment and disposal. 1: 1-304.
  30. Chang JH, Ellis AV, Yan CT, Tung CH (2009) The electrochemical phenomena and kinetics of EDTA- copper wastewater reclamation by electrodeposition and ultrasound. Sep Purif Technol 68(2): 216-221.
  31. Butler E, Hung YT, Yeh RYL, Suleiman Al Ahmad M (2011) Electrocoagulation in Wastewater Treatment. Water 3(2): 495-525.
  32. Means JL, Kucak T, Crerar DA (1980) Relative degradation rates of NTA, EDTA and DTPA and environmental implications. Environ Pollution Ser B, Chem Phys 1(1): 45-60.
  33. Elliott HA, Brown GA (1989) Comparative evaluation of NTA and EDTA for extractive decontamination of Pb-polluted soils. Water Air Soil Pollut 45(3-4): 361- 369.
  34. Alder AC, Siegrist H, Gujer W, Giger W (1990) Behaviour of NTA and EDTA in biological wastewater treatment. Water Res 24(6): 733-742.
  35. Da̧browski A, Hubicki Z, Podkoscielny P, Robens E (2004) Selective removal of the heavy metal ions from waters and industrial wastewaters by ion- exchange method. Chemosphere 56(2): 91-106.
  36. Kadirvelu K, Goel J (2005) Ion Exchange and Inorganic Adsorption. In: Water Encyclopedia.
  37. Naumczyk J, Rusiniak M (2005) Physicochemical and chemical purification of tannery wastewaters. Polish J Environ Stud 14: 789-797.
  38. Malaviya P, Singh A (2011) Physicochemical technologies for remediation of chromium-containing waters and wastewaters. Crit Rev Environ Sci Technol 41(12): 1111-1172.
  39. Dow Chemical Company (1999) Dowex Ion Exchange Resins: Fundamentals of Ion Exchange. Met Finish 97:69-70.
  40. Nagarale RK, Gohil GS, Shahi VK (2006) Recent developments on ion-exchange membranes and electro-membrane processes. Adv Colloid Interface Sci 119(2-3): 97-130.
  41. Siddique M, Farooq R, Shaeen A (2011) Removal of Reactive Blue 19 from wastewaters by physicochemical and biological processes-A Review. J Chem Soc Pakistan 33(2): 284-293.
  42. Kast W (1985) Principles of adsorption and adsorption processes. Chem Eng Process Process Intensif 19: 118.
  43. Kadirvelu K, Thamaraiselvi K, Namasivayam C (2001) Removal of heavy metals from industrial wastewaters by adsorption onto activated carbon prepared from an agricultural solid waste. Bio resource Technol 76(1): 63-65.
  44. Kyzas GZ, Kostoglou M (2014) Green adsorbents for wastewaters: A critical review. Materials (Basel) 7(1): 333-364.
  45. Chang Y, Lai JY, Lee DJ (2016) Thermodynamic parameters for adsorption equilibrium of heavy metals and dyes from wastewaters: Research updated. Bioresour Technol 222: 513-516.
  46. Weber WJ (1974) Adsorption processes. Pure Appl Chem 37(3): 375-392.
  47. Mezohegyi G, van der Zee FP, Font J, Fortuny A, Fabregat A (2012) Towards advanced aqueous dye removal processes: A short review on the versatile role of activated carbon. J Environ Manage 102: 148- 164.
  48. Aber S, Sheydaei M (2012) Removal of COD from industrial effluent containing indigo dye using adsorption method by activated carbon cloth: Optimization, kinetic, and isotherm studies. Clean-Soil Air Water 40(1): 87-94.
  49. Skouteris G, Saroj D, Melidis P, Hai FI, Ouki S (2015) The effect of activated carbon addition on membrane bioreactor processes for wastewater treatment and reclamation-A critical review. Bioresour Technol 185: 399-410.
  50. Yang QH, Li LX, Cheng HM, Wang M, Bai J (2003) Inner-tubular physicochemical processes of carbon nanotubes. Chinese Sci Bull 48(22): 2395-2403.
  51. Saleh TA (2013) The Role of Carbon Nanotubes in Enhancement of Photocatalysis. In: Syntheses and Applications of Carbon Nanotubes and Their Composites.
  52. Gupta VK, Saleh TA (2013) Sorption of pollutants by porous carbon, carbon nanotubes and fullerene- An overview. Environ Sci Pollut Res 20(5): 2828-2843.
  53. M Hamdi AI, Kandri NI, Zerouale A, Blumberga D, Gusca J (2016) Treatment and Physicochemical Characterisation of Red Wood Sawdust. Energy Procedia 95: 546-550.
  54. Varma AK, Mondal P (2016) Physicochemical characterization and pyrolysis kinetics of wood sawdust. Energy Sources, Part A Recover Util Environ Eff 38(17): 2536-2544.
  55. Sombatsompop N, Chaochanchaikul K, Phromchirasuk C, Thongsang S (2003) Effect of wood sawdust content on rheological and structural changes, and thermo-mechanical properties of PVC/sawdust composites. Polym Int 52(12): 1847- 1855.
  56. Auxenfans T, Buchoux S, Larcher D, Husson G, Husson E, et al. (2014) Enzymatic saccharification and structural properties of industrial wood sawdust: Recycled ionic liquids pretreatments. Energy Convers Manag 88: 1094-1103.
  57. Dai D, Fan M (2015) Preparation of bio-composite from wood sawdust and gypsum. Ind Crops Prod 74: 417-424.
  58. Batstone DJ, Amerlinck Y, Ekama G (2012) Towards a generalized physicochemical framework. Water Sci Technol 66(6): 1147-1161.
  59. Carvalho F, Prazeres AR, Rivas J (2013) Cheese whey wastewater: Characterization and treatment. Sci Total Environ 445-446: 385-396.
  60. Yadav A, Mukherji S, Garg A (2013) Removal of chemical oxygen demand and color from simulated textile wastewater using a combination of chemical/physicochemical processes. Ind Eng Chem Res 52: 10063-10071.
  61. Fu F, Wang Q (2011) Removal of heavy metal ions from wastewaters: A review. J Environ Manage 92(3): 407-418.
  62. Pugsley EB (1982) On “soluble‐sulfide precipitation for heavy metals removal from wastewaters.” Environ Prog 1(2): A8-A8.
  63. Altaş L, Buyukgungor H (2008) Sulfide removal in petroleum refinery wastewater by chemical precipitation. J Hazard Mater 153(1-2): 462-469.
  64. Can-Dogan E, Turker M, Dagasan L, Arslan A (2010) Sulfide removal from industrial wastewaters by lithotrophic denitrification using nitrate as an electron acceptor. Water Sci Technol 62(10): 2286- 2293.
  65. Perez RM, Cabrera G, Gomez JM, Abalosa A, Cantero D (2010) Combined strategy for the precipitation of heavy metals and biodegradation of petroleum in industrial wastewaters. J Hazard Mater 182(1-3): 896-902.
  66. Nguyen TA, Juang RS (2013) Treatment of waters and wastewaters containing sulfur dyes: A review Chem Eng J 219: 109-117.
  67. Kumpiene J, Lagerkvist A, Maurice C (2008) Stabilization of As, Cr, Cu, Pb and Zn in soil using amendments-A review. Waste Manag 28(1): 215-225.
  68. Tokuda H, Kuchar D, Mihara N, Kubota M, Matsuda H, et al. (2008) Study on reaction kinetics and selective precipitation of Cu, Zn, Ni and Sn with H2S in single- metal and multi-metal systems. Chemosphere 73(9): 1448-1452.
  69. Bratskaya SY, Pestov AV, Yatluk YG, Avramenko VA (2009) Heavy metals removal by flocculation/precipitation using N-(2- carboxyethyl)chitosans. Colloids Surfaces A Physicochem Eng Asp 339(1-3): 140-144.
  70. Fuchs W, Binder H, Mavrias G, Braun R (2003) Anaerobic treatment of wastewater with high organic content using a stirred tank reactor coupled with a membrane filtration unit. Water Res 37(4): 902-908.
  71. Sostar-Turk S, Petrinic I, Simonic M (2005) Laundry wastewater treatment using coagulation and membrane filtration. Resour Conserv Recycl 44(2): 185-196.
  72. Busch J, Cruse A, Marquardt W (2007) Modeling submerged hollow-fiber membrane filtration for wastewater treatment. J Memb Sci 288(1-2): 94-111.
  73. Wen C, Huang X, Qian Y (1999) Domestic wastewater treatment using an anaerobic bioreactor coupled with membrane filtration. Process Biochem 35(3-4): 335- 340.
  74. Melin T, Jefferson B, Bixio D, Thoeye C, De Wilde W, et al. (2006) Membrane bioreactor technology for wastewater treatment and reuse. Desalination 187(1- 3): 271-282.
  75. Borbély G, Nagy E (2009) Removal of zinc and nickel ions by complexation-membrane filtration process from industrial wastewater. Desalination 240(1-3): 218-226.
  76. Lateef SK, Soh BZ, Kimura K (2013) Direct membrane filtration of municipal wastewater with chemically enhanced backwash for recovery of organic matter. Bioresour Technol 150: 149-155.
  77. Chen X, Shen Z, Zhu X, Fan Y, Wang W, et al. (2005) Advanced treatment of textile wastewater for reuse using electrochemical oxidation and membrane filtration. Water SA 31(1): 127-132.
  78. Pearce G (2007a) Water and wastewater filtration: Membrane module format. Filtr Sep 44(4): 31-33.
  79. Pearce G (2007b) Water and wastewater filtration: Process design. Filtr Sep 44(5): 36-38.
  80. Van Der Bruggen B, Vandecasteele C, Van Gestel T, Doyen W, Leysen R (2003) A review of pressure- driven membrane processes in wastewater treatment and drinking water production. Environ Prog 22(1): 46-56.
  81. Gönder ZB, Kaya Y, Vergili I, Barlas H (2010) Optimization of filtration conditions for CIP wastewater treatment by nanofiltration process using Taguchi approach. Sep Purif Technol 70(3): 265-273.
  82. Li H, Shi W, Wang W, Zhu H (2015) The extraction of sericin protein from silk reeling wastewater by hollow fiber nanofiltration membrane integrated process. Sep Purif Technol 146: 342-350.
  83. Sayed S, Tarek S, Dijkstra I, Moerman C (2007) Optimum operation conditions of direct capillary nanofiltration for wastewater treatment. Desalination 214(1-3): 215-226.
  84. Van Der Bruggen B, Geens J (2008) Nanofiltration. In: Advanced Membrane Technology and Applications, pp: 271-295.
  85. Fogarassy E, Galambos I, Bekassy-Molnar E, Vatai G (2009) Treatment of high arsenic content wastewater by membrane filtration. Desalination 240(1-3): 270- 273.
  86. Rossignol N, Vandanjon L, Jaouen P, Quemeneur F (1999) Membrane technology for the continuous separation microalgae/culture medium: Compared performances of cross-flow microfiltration and ultrafiltration. Aquac Eng 20(3): 191-208.
  87. Benitez FJ, Acero JL, Leal AI (2006) Application of microfiltration and ultrafiltration processes to cork processing wastewaters and assessment of the membrane fouling. Sep Purif Technol 50(3): 354-364.
  88. Park SY, Choi SH, Chung JW, Kwak SY (2015) Anti- scaling ultrafiltration/microfiltration (UF/MF) polyvinylidene fluoride (PVDF) membranes with positive surface charges for Ca2+/silica-rich wastewater treatment. J Memb Sci 480: 122-128.
  89. Kennedy MD, Kamanyi J, Salinas Rodriguez SG, Lee NH, Schippers JC, Amy G (2008) Water Treatment by Microfiltration and Ultrafiltration. In: Advanced Membrane Technology and Applications, pp: 131- 170.
  90. Gallego-Molina A, Mendoza-Roca JA, Aguado D, Galiana-Aleixandre MV (2013) Reducing pollution from the deliming-bating operation in a tannery. Wastewater reuse by microfiltration membranes. Chem Eng Res Des 91(2): 369-376.
  91. Shimizu Y, Okuno YI, Uryu K, Ohtsubo S, Watanabe A (1996) Filtration characteristics of hollow fiber microfiltration membranes used in membrane bioreactor for domestic wastewater treatment. Water Res 30: 2385-2392.
  92. Arevalo J, Ruiz LM, Parada-Albarracin JA, Gonzalez- Perez DM, Perez J, et al. (2012) Wastewater reuse after treatment by MBR. Microfiltration or ultrafiltration?. Desalination 299: 22-27.
  93. Strathmann H (2010) Electrodialysis, a mature technology with a multitude of new applications. Desalination 264(3): 268-288.
  94. Ilhan F, Kabuk HA, Kurt U, Avsar Y, Sari H, et al. (2014) Evaluation of treatment and recovery of leachate by bipolar membrane electrodialysis process. Chem Eng Process Process Intensif 75: 67- 74.
  95. Deghles A, Kurt U (2016) Treatment of tannery wastewater by a hybrid electrocoagulation/electrodialysis process. Chem Eng Process Process Intensif 104: 43-50.
  96. Lee S, Lueptow RM (2001) Reverse osmosis filtration for space mission wastewater: membrane properties and operating conditions. J Memb Sci 182(1-2): 77- 90.
  97. Cath TY, Gormly S, Beaudry EG, Flynn MT, Adams VD, et al. (2005) Membrane contactor processes for wastewater reclamation in space: Part I. Direct osmotic concentration as pretreatment for reverse osmosis. J Memb Sci 257(1-2): 85-98.
  98. Cath T, Childress A, Elimelech M (2006) Forward osmosis: Principles, applications, and recent developments. J Memb Sci 281(1-2):70-87.
  99. Chon K, Kim SJ, Moon J, Cho J (2012) Combined coagulation-disk filtration process as a pretreatment of ultrafiltration and reverse osmosis membrane for wastewater reclamation: An autopsy study of a pilot plant. Water Res 46(6): 1803-1816.
  100. Chon K, Cho J, Shon HK (2013) A pilot-scale hybrid municipal wastewater reclamation system using combined coagulation and disk filtration, ultrafiltration, and reverse osmosis: Removal of nutrients and micropollutants, and characterization of membrane foulants. Bioresour Technol 141: 109- 116.
  101. Saliby I El, Shon H, Kandasamy J, Vigneswaran S (1999) Nanotechnology for Wastewater Treatment: in Brief. Water Wastewater Treat Technol, pp: 1-15.
  102. Karn B, Kuiken T, Otto M (2009) Nanotechnology and in situ remediation: A review of the benefits and potential risks. Environ. Health Perspect 117(12): 1823-1831.
  103. Webster TJ (2011) Nanotechnology enabled in situ sensors for monitoring health.
  104. Bora T, Dutta J (2014) Applications of Nanotechnology in Wastewater Treatment-A Review. J Nanosci Nanotechnol 14(1): 613-626.
  105. Lorenz WJ, Plieth W (2007) Electrochemical Nanotechnology: In-situ Local Probe Techniques at Electrochemical Interfaces.
  106. Brar SK, Verma M, Tyagi RD, Surampalli RY (2010) Engineered nanoparticles in wastewater and wastewater sludge-Evidence and impacts. Waste Manag 30(3): 504-520.
  107. Sharma V, Sharma A (2012) Nanotechnology: An Emerging Future Trend in Wastewater Treatment with its Innovative Products and Processes. Int J Enhanc Res Sci Technol Eng 1(2): 1-8.
  108. Robert D, Malato S (2002) Solar photocatalysis: A clean process for water detoxification. Sci Total Environ 291(1-3): 85-97.
  109. Agustina TE, Ang HM, Vareek VK (2005) A review of synergistic effect of photocatalysis and ozonation on wastewater treatment. J Photochem Photobiol C Photochem Rev 6(4): 264-273.
  110. Chen D, Ray AK (2001) Removal of toxic metal ions from wastewater by semiconductor photocatalysis. Chem Eng Sci 56(4): 1561-1570.
  111. Jiang B, Zhang S, Guo X, Jin B, Tian Y (2009) Preparation and photocatalytic activity of CeO2/TiO2 interface composite film. Appl Surf Sci 255(11): 5975- 5978.
  112. Elmolla ES, Chaudhuri M (2011) The feasibility of using combined TiO2 photocatalysis-SBR process for antibiotic wastewater treatment. Desalination 272(1- 3): 218-224.
  113. Wang Y, Hu B, Hu C, Zhou X (2015) Fabrication of a novel Ti/SnO2–Sb–CeO2@TiO2–SnO2 electrode and photoelectrocatalytic application in wastewater treatment. Mater Sci Semicond Process 40: 744-751.
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@article{kunal2019,
  title   = {Advanced Techniques for Wastewater Treatment: A Review},
  author  = {Kunal, Rajput S and Yadav S},
  journal = {Open Access Journal of Waste Management & Xenobiotics},
  year    = {2019},
  volume  = {2},
  number  = {3},
  doi     = {10.23880/oajwx-16000126}
}
Kunal, Rajput S and Yadav S (2019). Advanced Techniques for Wastewater Treatment: A Review. Open Access Journal of Waste Management & Xenobiotics, 2(3). https://doi.org/10.23880/oajwx-16000126
TY  - JOUR
TI  - Advanced Techniques for Wastewater Treatment: A Review
AU  - Kunal, Rajput S and Yadav S
JO  - Open Access Journal of Waste Management & Xenobiotics
PY  - 2019
VL  - 2
IS  - 3
DO  - 10.23880/oajwx-16000126
ER  -