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Biobased Approaches Towards Treatment and Recycling of Heavy Metals from Wastewater
Published in Gunjan Mukherjee, Sunny Dhiman, Waste Management, 2023
Heavy metals are introduced into the environment through natural or anthropogenic sources. Examples of natural sources are erosion and volcanic eruptions Anthropogenic sources include agricultural, municipal, and industrial wastewaters. The United Nations’ World Water Assessment Programme estimates that over 80% of wastewater globally is discharged into the environment without prior treatment. The 2017 World Water Development Report shows a survey done on Canadian industries which reveals 34% of wastewater discharged from manufacturing plants goes untreated, 57.9% from thermal-electric power plants, and 43.8% from mining sites (WWAP 2017). Due to untreated sewage discharge, heavy metal concentrations were examined in Tembi River, Iran (Shanbehzadeh et al. 2014). The authors concluded that the river water is polluted and is not safe for consumption and aquatic life. Concentrations of the detected heavy metals are summarized in Table 1. Although detailed statistics on global wastewater discharge is still deficient, it is clear that efforts for effective treatment of industrial wastewater is critical in preventing detrimental effects in the long run.
Reclamation and Phytoremediation of Heavy Metal Contaminated Land
Published in Jos T. Puthur, Om Parkash Dhankher, Bioenergy Crops, 2022
E. Janeeshma, Akhila Sen, K.P. Raj Aswathi, Riya Johnson, Om P. Dhankher, Jos T. Puthur
Heavy metals are elements having high density, atomic weight and number. Mercury (Hg), copper (Cu), cadmium (Cd), zinc (Zn), chromium (Cr), nickel (Ni), arsenic (As) and lead (Pb) are the common heavy metals originating from both natural or anthropogenic sources and causes pollution at a greater extent (Singh et al. 2011, Sarath and Pothur 2020). Heavy metals present in the soil for a long time are a major hazard to the environment (Suman et al. 2018). Land and water pollution due to heavy metal contamination is a significant risk at the global level. All the countries face this situation, but the intensity may vary depending on the area and severity of affecting pollution.
Reducing Heavy Metal Toxicity using Biochar as a Naturally Derived Adsorbent
Published in Ram Naresh Bharagava, Sandhya Mishra, Ganesh Dattatraya Saratale, Rijuta Ganesh Saratale, Luiz Fernando Romanholo Ferreira, Bioremediation, 2022
Iqbal Azad, Tahmeena Khan, Bhanu Pratap, Abdul Rahman Khan
As, Cd, Pb, Cu, Hg, Cr and Zn are all are included in the list of priority toxic pollutants and toxic trace metals, and these are the highest toxic heavy metals in the environment. They cause high toxicity in various environmental constituents, including water, air, soil, plants, animals and wildlife. Due to natural and anthropogenic activities, heavy metals are released and cause pollution in water system, sediments and soils. Various factors such as physicochemical and climatic properties affect the biogeochemical cycling and global dynamics of heavy metals in the environmental system. In toxicological investigation, the general mode of uptake of heavy metals is found to be inhalation, ingestion and dermal absorption. In the living organism, absorption occurs through active or passive diffusion (Tchounwou et al. 2012). Numerous factors such as gender, age, method of exposure, different susceptibilities and time interval of contact are used to determine the health risks posed by these heavy metals. The contaminated water affects every living being. Human beings are more susceptible to severe health hazards because of the greater uptake of heavy metals in the food chain (Jaishankar et al. 2014).
Pyrene and lead transport in unsaturated soil at two different water saturations
Published in Soil and Sediment Contamination: An International Journal, 2022
Mariem Kacem, Jihène Aissaoui, Arbi Mgaidi, Philippe Dubujet
Most polluted sites are contaminated with mixtures of inorganic and organic compounds. Among these pollutants are polycyclic aromatic hydrocarbon (PAHs) and heavy metals (HMs). PAHs are neutral, hydrophobic, and nonpolar molecules with low solubility in water and low volatility. They are composed of at least two fused aromatic rings. Heavy metals are metals with relatively high densities or atomic weights. Depending on the considered HMs and soil several reactions can occur in the soil as complexation and oxidation. Like PAHs, HMs are readily absorbable on soil and it was proven the interaction between those compounds and possible competition of their interaction with the soil. Depending on the considered coexisting molecules and the chemical of porous media, competition on adsorption sites can be existing (Ye et al. 2017).
Microalgae and bio-polymeric adsorbents: an integrative approach giving new directions to wastewater treatment
Published in International Journal of Phytoremediation, 2022
Palak Saket, Mrinal Kashyap, Kiran Bala, Abhijeet Joshi
Increasing urbanization, industrialization, agricultural and medical technologies led to the wide distribution of pesticides, heavy metals, dyes, pharmaceuticals, and radioactive pollutants across air, water and soil. These pollutants are arousing concerns for their significant effects on human health and the environment. 12th 5-year plan for Comprehensive Prevention and Control of heavy metal pollution of China has suggested that chromium, cadmium, palladium and mercury as metalloids with higher priority for control over other metals (Fu et al.2017). Heavy metals deplete the antioxidants of a cell significantly, especially those enzymes and antioxidants having a thiol group, which lead to reactive oxygen species generation and cause oxidative stress (Ballesteros Martín et al.2009). Different heavy metals have various health effects; for example, cadmium can cause pulmonary and kidney damage (Seidal et al.1993; Järup et al.1998).
Application of the response surface methodology (RSM) in heavy metal removal from real power plant wastewater using electrocoagulation
Published in European Journal of Environmental and Civil Engineering, 2022
Zahra Beiramzadeh, Mohamadtaqi Baqersad, Mohammad Aghababaei
Wastewater samples were collected from Shahid Rajaee steam-thermal power plant located in the distance of about 25 kilometres to Qazvin city, at the centre of Iran. Wastewater discharged from the boiler and air preheater chemical cleaning and washing section predominantly contain heavy metals, total suspended solids (TSS), COD, chloride and sulphate. The role of preheater is to improve boilers efficiency by preheating the combustion air before entering the furnace. It worked well when it was maintained clean and prevented from airside fouling. Boilers surfaces contacted with water were cleaned from dirt, the subsequent passivation layer, and rust to maintain the quality of steam at turbine inlet, minimise corrosion of metal surfaces, and improve the heat transfer of the system. After homogenising the collected samples, experiments were performed to determine the initial characteristics of the wastewater. Chloride and sulphate were measured using the standard method presented by photometer Palintest 7100 and spectrophotometer Hach DR3900, respectively. Samples were prepared based on the standard method given in Section 2.3. Heavy metal concentrations were measured by atomic absorption spectrometry. Table 2 shows the general characteristics of the wastewater.