Biochar:An Emerging Panacea for Remediation of Soil Contaminants from Mining,Industry and Sewage Wastes

Mine tailings, waste rock piles, acid mine drainage, industrial wastewater, and sewage sludge have contaminated a vast area of cultivable and fallow lands, with a consequence of deterioration of soil and water quality and watercourses due to the erosion of contaminated soils for absence of vegetative cover. High concentrations of toxic elements, organic contaminants, acidic soils, and harsh climatic conditions have made it difficult to re-establish vegetation and produce crops there. Recently, a significant body of work has focussed on the suitability and potentiality of biochar as a soil remediation tool that increases seed emergence, soil and crop productivity, above ground biomass, and vegetation cover on mine tailings, waste rock piles, and industrial and sewage wastecontaminated soils by increasing soil nutrients and water-holding capacity, amelioration of soil acidity, and stimulation of microbial diversity and functions. This review addresses: i) the functional properties of biochar, and microbial cycling of nutrients in soil; ii)bioremediation, especially phytoremediation of mine tailings, industrial waste, sewage sludge, and contaminated soil using biochar; iii)impact of biochar on reduction of acid production, acid mine drainage treatment, and geochemical dynamics in mine tailings; and iv)treatment of metal and organic contaminants in soils using biochar, and restoration of degraded land.

Comparative Assessment of the Effect of Wastewater Sludge Biochar on Growth,Yield and Metal Bioaccumulation of Cherry Tomato

To investigate the potential effects of wastewater sludge and sludge biochar on growth, yield and metal bioaccumulation of cherry tomato(Lycopersicon esculentum L.), a pot experiment was carried out under greenhouse environment with three different treatments,control soil(CP), soil with wastewater sludge(SS) and soil with sludge biochar(SB), to reveal the comparative effect between the amendments of wastewater sludge and sludge biochar. The soil used for pot experiment was Chromosol. Wastewater sludge and sludge biochar produced through pyrolysis process at 550?C were applied at 10 t ha-1. No significant difference was found in growth and production of cherry tomatoes between wastewater sludge and sludge biochar applications to the soil. The accumulation rates of metals in the fruits were lower in the treatment with sludge biochar than in the treatment with wastewater sludge. The study highlights the benefits of risk mitigation from toxic metal accumulation in fruits using wastewater sludge and sludge biochar as soil conditioners.

Temporal and spatial variations of air pollution across China from 2015 to 2018

This study investigated concentrations of PM_(2.5),PM_(10),SO_(2),NO_(2),CO and O_(3),and air quality index(AQI)values across 368 cities in China's Mainland during 2015–2018.The study further examined relationships of air pollution status with local industrial capacities and vehicle possessions.Strong correlations were found between industrial capacities(coal,pig iron,crude steel and rolled steel)and air pollution levels.Although statistical and significant reductions of PM_(2.5),PM_(10),SO_(2),NO_(2),CO and AQI values were observed in response to various laws and regulations in industrial sectors,both particle and gaseous pollutants still had annual average concentrations above recommended limits.In order to further reduce air pollution,more efforts can be done to control traffic emissions caused by minicars and heavy trucks,which was revealed after investigating 16 vehicle types.This was also consistent with the apparent air quality improvement during the COVID-19 lockdown period in China in 2020,despite industrial operations being still active at full capacities.

Antibiotic enhanced dopamine polymerization for engineering antifouling and antimicrobial membranes

In this work,we adopt a new tobramycin(TOB)-dopamine coating system to endow thin film composite membranes with excellent antifouling and antimicrobial properties.Combining the hydrophilic and antibiofouling properties of both TOB and polydopamine,the TOB-dopamine modified membrane exhibits improved antifouling and antimicrobial properties compared with the conventional dopamine modified and unmodified membranes.The TOB-dopamine system has two advantages over the conventional modification with dopamine and tris buffer solution.First,TOB-dopamine modification is more efficient than the conventional dopamine modification due to the accelerating effect of TOB on dopamine polymerization.Second,the TOB-dopamine modified membranes exhibit better hydrophilicity,and enhanced antifouling and antimicrobial properties than the conventional dopamine modified membrane.Beyond engineering membranes,the proposed TOB-dopamine system can also be extended for wider surface hydrophilic and antimicrobial modifications.