The advancements in the field of sludge and biosolids have been made over the past year. This review outlines the major contributions of researchers that have been published in peer-reviewed journals and conference proceedings throughout 2018. The review is organized in sections including regulatory developments and market analysis; analysis and quantification of characteristics including microconstituents and metals; treatment advances for the conversion of sludge to biosolids including pretreatment and sludge minimization, conditioning and dewatering, digestion, composting, and innovative technologies; product development and reuse including adsorbents and thermal products, agricultural and other uses, and innovative uses; odor and air emissions; and energy factors. PRACTITIONER POINTS: Summary of advances in the field of residuals and biosolids research in 2018. This review outlines the major contributions of researchers that have been published in peer-reviewed journals and conference proceedings. Topics covered range from regulation to innovation.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/wer.1212

Biosolids and sludge management

Covalently linked graphene oxide/reduced graphene oxide-methoxylether polyethylene glycol functionalised silica for scavenging of estrogen: Adsorption performance and mechanism.

Effects of veterinary antibiotics on the fate and persistence of 17β-estradiol in swine manure

Electroforced sedimentation (EFS) is a well-known technique for enhancing the solid content of the final sludge cake. However, the parameters affecting the performance of EFS and quality of the resulting sludge cake, as well as the removed water, are not sufficiently studied. In this research, a mixture of zinc oxide (representing sludge) and polyacrylamide (dewatering aid) were used as experimental materials. The process parameters of electroforced sedimentation were optimized using a design of experiment software (Design Expert
 ® Version 7.0.0) with a face-centered central composite design (FCCCD) under response surface methodology. An optimization study was carried out for the output response (sedimentation velocity) based on three process factors and an empirical model was developed. The optimized values for current density, total solid volume per unit cross-sectional area and polyacrylamide dose for the highest sedimentation velocity (0.0199 cm/min) were 6.0 A/m2, 7.74 mm and 1.53 % (based on the weight of zinc oxide), respectively. The overall model was significant with Prob > F value of 0.0117 and R
 2 value of 0.8911 while the most significant parameter was observed to be the current density with a Prob > F value of 0.0004. Validation experiments were conducted to confirm and measure the accuracy of the models for the three set of parameters including optimum parameters. The error was within the limit of prediction accuracy, and the sedimentation velocity was enhanced by the addition of 1.53 % PAM as dewatering aid. Thus, it was concluded that EFS can be applied successfully for materials having permanent charge.

Study of the Effects of Process Parameters on Electroforced Sedimentation in Solid–Liquid Separation Using Response Surface Methodology

Natural steroidal estrogens, such as 17 β-estradiol (E2), as well as antimicrobials such as doxycycline and norfloxacin, are excreted by humans and hence detected in sewage sludge and biosolid. The disposal of human waste products on agricultural land results in estrogens and antibiotics being detected as mixtures in soils. The objective of this study was to examine microbial respiration and E2 mineralization in sewage sludge, biosolid, and soil in the presence and the absence of doxycycline and norfloxacin. The antimicrobials were applied to the media either alone or in combination at total rates of 4 and 40 mg kg-1, with the 4 mg kg-1 rate being an environmentally relevant concentration. The calculated time that half of the applied E2 was mineralized ranged from 294 to 418 days in sewage sludge, from 721 to 869 days in soil, and from 2,258 to 14,146 days in biosolid. E2 mineralization followed first-order and the presence of antimicrobials had no significant effect on mineralization half-lives, except for some antimicrobial applications to the human waste products. At 189 day, total E2 mineralization was significantly greater in sewage sludge (38 ±0.7%) > soil (23 ±0.7%) > biosolid (3 ±0.7%), while total respiration was significantly greater in biosolid (1,258 mg CO2) > sewage sludge (253 mg CO2) ≥ soil (131 mg CO2). Strong sorption of E2 to the organic fraction in biosolid may have resulted in reduced E2 mineralization despite the high microbial activity in this media. Total E2 mineralization at 189 day was not significantly influenced by the presence of doxycycline and/or norfloxacin in the media. Antimicrobial additions also did not significantly influence total respiration in media, except that total CO2 respiration at 189 day was significantly greater for biosolid with 40 mg kg-1 doxycycline added, relative to biosolid without antimicrobials. We conclude that it is unlikely for doxycycline and norfloxacin, or their mixtures, to have a significant effect on E2 mineralization in human waste products and soil. However, the potential for E2 to be persistent in biosolids, with and without the presence of antimicrobials, is posing a challenge for biosolid disposal to agricultural lands.

/pdf/17-b-estradiol-mineralization-in-human-waste-products-and-2rcjo06poo.pdf

17 β-estradiol mineralization in human waste products and soil in the presence and the absence of antimicrobials.

Natural steroid estrogens (e.g., 17 β-estradiol, E2), synthetic steroid estrogens (e.g., 17 α-ethinylestradiol, EE2) and pharmaceutical antibiotics (e.g., ciprofloxacin) are chemicals detected in biosolids and sewage sludges because they partition into the solids fraction during the wastewater treatment process. This research utilized a three-way factorial design (six media × two estrogens × three antibiotic treatments) to quantify cumulative E2 and EE2 mineralization over 133 d (MAX) in a range of sewage sludge and biosolid samples in the presence (4 and 40 mg kg(-1)) and absence of ciprofloxacin. The same three-way factorial design was utilized to quantify the impact of the six media, E2 or EE2, and ciprofloxacin on cumulative soil respiration over 133 d (RESP). Minimal ciprofloxacin mineralization was observed ( primary sewage sludge > biosolid = composted biosolid. This suggests that sewage sludges in municipal lagoons and pre-treatment holding lagoons are a more favorable media for mineralization of EE2, whereas biosolids in post-treatment storage lagoons are a more favorable media for the mineralization of E2. The presence of ciprofloxacin will have no impact on the potential E2 or EE2 mineralization rates in these cases.

Bruna Ascef

Papers

17 β-estradiol and 17 α-ethinylestradiol mineralization in sewage sludge and biosolids

17 β-estradiol mineralization in human waste products and soil in the presence and the absence of antimicrobials.