A potential application of sludge-based catalysts for the anaerobic bio-decolorization of tartrazine dye

Bisphenol A contamination in aquatic environments: a review of sources, environmental concerns, and microbial remediation

The production of polycarbonate, a high-performance transparent plastic, employs bisphenol A, which is a prominent endocrine-disrupting compound. Polycarbonates are frequently used in the manufacturing of food, bottles, storage containers for newborns, and beverage packaging materials. Global production of BPA in 2022 was estimated to be in the region of 10 million tonnes. About 65-70% of all bisphenol A is used to make polycarbonate plastics. Bisphenol A leaches from improperly disposed plastic items and enters the environment through wastewater from plastic-producing industries, contaminating, sediments, surface water, and ground water. The concentration BPA in industrial and domestic wastewater ranges from 16 to 1465 ng/L while in surface water it has been detected 170-3113 ng/L. Wastewater treatment can be highly effective at removing BPA, giving reductions of 91-98%. Regardless, the remaining 2-9% of BPA will continue through to the environment, with low levels of BPA commonly observed in surface water and sediment in the USA and Europe. The health effects of BPA have been the subject of prolonged public and scientific debate, with PubMed listing more than 17,000 scientific papers as of 2023. Bisphenol A poses environmental and health hazards in aquatic systems, affecting ecosystems and human health. While several studies have revealed its presence in aqueous streams, environmentally sound technologies should be explored for its removal from the contaminated environment. Concern is mostly related to its estrogen-like activity, although it can interact with other receptor systems as an endocrine-disrupting chemical. Present review article encompasses the updated information on sources, environmental concerns, and sustainable remediation techniques for bisphenol A removal from aquatic ecosystems, discussing gaps, constraints, and future research requirements.

Optimized adsorption onto biosolids-based activated carbon for tartrazine removal from wastewater

This study investigates optimized tartrazine uptake by activated carbon prepared from biosolids (BBAC). Different tartrazine concentrations (10-20 mg/L), adsorbent dosages (1.0-2.0 g), pH (2.0-4.0), and contact times (60-120 min) were tested. These independent variables formed a 2⁴ full factorial experiment arranged as central composite rotative design (CCRD). Response surface methodology (RSM) analyzed the responses of 50 experimental runs. Tartrazine removal efficiency fluctuated between 76.2% and 99.9%. The experimental data were best fitted by a quadratic model (R²  > 0.95, p > 0.0001). All variables exerted statistically significant (p < 0.05) effects on the tartrazine uptake (initial concentration, p = 0.0011; BBAC dosage, p = 0.0004; pH, p < 0.0001; contact time, p < 0.0001). Optimized tartrazine uptake efficiency of 97.4% can happen when variables mutually correlate at 10.1 mg/L of tartrazine concentration, 1.07 g of adsorbent dosage, 2.13 of pH, and 116.9 min of contact time. PRACTITIONER POINTS: Production of biosolids-based activated carbon (BBAC) is presented. Adsorptive affinity to tartrazine in aqueous solution was experimented. Experimental conditions optimized by Response Surface Methodology.

Urea-modified grass ash activated sludge carbon: structure and adsorption properties towards H2S and CH3SH

The deodorization structure of H₂S and CH₃SH adsorbed by sludge carbon was studied, and the deodorized product was analyzed.