Investigation of the adsorption-reduction mechanisms of hexavalent chromium by ramie biochars of different pyrolytic temperatures

J of Chemical Tech & Biotech

et al. 2017

BACKGROUND Antibiotics are widely used for the treatment of bacterial infections in humans and animals, but it can be released into water sources due to incomplete metabolism in humans or via discharge from drug manufacturers. RESULTS The efficiency of removal of three antibiotics was enhanced with increasing biochar dosage. The adsorption of three antibiotics by RH700 was much higher than by RH300 and RH500, which might be due to the larger surface area and adsorption pore volume of RH700 (211.76 m2 g‐1 and 6.25 nm, respectively). In addition, the adsorption capacity was greatly affected by the solution pH, background electrolyte and humic acid. The kinetics experiment data were well fitted by the pseudo‐second‐order kinetic model. The maximum adsorption capacities of tetracycline hydrochloride (TC), doxycycline hydrochloride (DC) and ciprofloxacin (CF) based on the Langmuir model by RH700 at 318 K were 80.9, 85.2 and 36.1 mg g‐1, respectively. RH700 exhibited high affinity for antibiotics, mainly ascribed to the chemical interaction between oxygen‐containing functional groups (phenolic hydroxyl group, carboxyl and alkoxy groups) of the biochar surface and TC, DC and CF. CONCLUSION The rice husk biochar produced at high temperature could be applied as a potential adsorbent for removal of antibiotics from water. © 2017 Society of Chemical Industry

Section: Resultsmentioning

confidence: 99%

Comparative study of rice husk biochars for aqueous antibiotics removal

Zeng

Tian

J of Chemical Tech & Biotech

et al. 2017

“…Furthermore, the time-courses of TC sorption onto CLDHs/BC were analyzed with a two-compartment and first-order dynamics model (presented in the Supplementary data)35. This kinetics model considered the adsorption of TC by CLDHs/BC as a two-domain process, which could be divided into “fast” and “slow” compartments.…”

Section: Resultsmentioning

confidence: 99%

One-pot synthesis of carbon supported calcined-Mg/Al layered double hydroxides for antibiotic removal by slow pyrolysis of biomass waste

Tan

et al. 2016

Sci Rep

Self Cite

111

A biochar supported calcined-Mg/Al layered double hydroxides composite (CLDHs/BC) was synthesized by a one-pot slow pyrolysis of LDHs preloaded bagasse biomass. Multiple characterizations of the product illustrated that the calcined-Mg/Al layered double hydroxides (CLDHs) were successfully coated onto the biochar in slow pyrolysis of pre-treated biomass. The as-synthesized CLDHs/BC could efficiently remove antibiotic tetracycline from aqueous solutions. The coating of CLDHs significantly increased the adsorption ability of biochar, and CLDHs/BC exhibited more than 2 times higher adsorption capacity than that of the pristine biochar (BC) in the tested pH range. The maximum adsorption capacity of CLDHs/BC for tetracycline was 1118.12 mg/g at 318 K. The experimental results suggested that the interaction with LDHs on biochar played a dominant role in tetracycline adsorption, accompanied with π–π interaction and hydrogen bond. This study provides a feasible and simple approach for the preparation of high-performance material for antibiotics contaminated wastewater treatment in a cost-effective way.

“…Raw BC used for the synthesis was obtained as described elsewhere . The ramie bars used as the biomass were obtained from farms in Changsha City, Hunan Province, China.…”

Section: Experimental Materials and Methodsmentioning

confidence: 99%

Titanium dioxide‐coated biochar composites as adsorptive and photocatalytic degradation materials for the removal of aqueous organic pollutants

Cai

Jiang

J of Chemical Tech & Biotech

et al. 2017

Self Cite

BACKGROUND This article reports the synthesis and characterisation of titanium dioxide‐coated biochar composites (TBCs) by pyrolysing titanium dioxide‐treated biomass prepared by a modified sol–gel method. Their adsorptive and photocatalytic activities were evaluated based on the removal of safranine T (ST) from an aqueous solution with/without UV‐light irradiation. RESULTS Characterisation studies suggested that TiO2 was successfully loaded on the biochar substrate. The biochar and TiO2 contents of the composite significantly affected its performance. The ST removal capabilities of the TBCs with 1, 1.5, 2, and 2.5 g of the biomass are 1.7, 2.3, 7.2, and 2.3 times better than that of the raw biochar, respectively. Thus, the optimum amount of biomass in TBC‐x was determined to be 2 g, with the corresponding sample exhibiting excellent stability, effectiveness over a wide pH range, and a maximum ST removal capacity of 226.7 mg g‐1. CONCLUSION The loading of TiO2 significantly enhanced the adsorption performance of biochar and the high specific surface area of the biochar synergistically promoted the photocatalytic activity of TiO2. Both adsorption and photocatalytic degradation were confirmed to contribute to the decolourisation of the aqueous solution because of the removal of ST, with the effect of adsorption being slightly higher than that of photocatalysis. The synthesised composite is a promising alternative material for removing chemical contaminants. © 2017 Society of Chemical Industry