Microfibers in anaerobic digestion: Effect of ozone pretreatment.

Wastewater treatment plants receive significant microplastics, which are eventually discharged into the environment. Previous studies indicated that over 90% of microplastics, especially microfibers from laundry wastewater, are retained in primary sludge. The effect of microfibers from household laundry on anaerobic digestion has yet to be fully understood, which is the objective of the present study.

Floral waste synthesized silver nanoparticles as sensor for Cr (VI) ion detection.

The presence of heavy metal ions, particularly Cr (VI) in water, is a serious environmental concern. There is a need to develop low-cost and efficient methods for sensing and removing Cr (IV) ions selectively. In this paper, floral waste (FW) extract is used for the synthesis of Ag NPs for sensing Cr (VI) ions in an aqueous solution.

Adsorption isotherms and kinetics for the removal of algal organic matter by granular activated carbon.

Seasonal algal blooms in surface water release a significant amount of algal organic matter (AOM), which alters the composition of dissolved organic matter (DOM). AOM affects the drinking water treatment processes and finished water quality. In this study, the relative removal efficiency of AOM and humic acid by granular activated carbon (GAC) adsorption was determined.

Simultaneous quantification of five pharmaceuticals and personal care products in biosolids and their fate in thermo-alkaline treatment.

The presence of pharmaceuticals and personal care products (PPCPs) in biosolids applied to farmland is of concern due to their potential accumulation in the environment and the subsequent effects on humans. Thermo-alkaline hydrolysis (TAH) is a method used for greater stabilization of biosolids after anaerobic digestion. In this work, the effect of TAH on five selected PPCPs including fluoroquinolone antibiotics, ciprofloxacin (CIP), and ofloxacin (OFLX), and three commonly used antimicrobial agents, miconazole (MIC), triclosan (TCS) and triclocarban (TCC) was evaluated.

Fate of micropollutants in chemically enhanced primary treatment using recovered coagulants.

In this study, the fate of several micropollutants (MPs) in wastewater due to coagulation using both fresh and recovered aluminum and iron coagulants was determined. 18 MPs from different groups such as antibiotics, food additives, and surfactants were selected and spiked into the primary influent collected from a local wastewater plant. The distribution of MPs in the recovered coagulant and treated effluent after coagulation was determined for both fresh and recycled coagulants.

Coagulation and disinfection by-products formation potential of extracellular and intracellular matter of algae and cyanobacteria.

Coagulation and flocculation can remove particulate algal cells effectively; however, they are not very effective for removing dissolved algal organic matter (AOM) in drinking water plants. In this work, optimum coagulation conditions using alum for both extracellular and intracellular organic matter of six different algal and cyanobacterial species were determined. Different coagulation conditions such as alum dosage, pH, and initial dissolved organic carbon (DOC) were tested.

Effect of COD/N ratio on denitrification from nitrite.

The objective of this study was to investigate dynamic specific denitrification rates (SDNRs) from nitrite at various chemical oxygen demand (COD)/nitrogen (N) ratios using municipal wastewater (MWW). A sequencing batch reactor (SBR) continuously fed with primary effluent and nitrite solution was operated at hydraulic retention time of 8.4 hr and solids retention time of 26-30 days for 3 months.

Assessment of water samples with complex compositions using microalgal bioassay based on the community level physiological profiling (CLPP).

The ability to effectively characterize the response of microalgal communities to changes in water quality is limited. Earlier, a microalgal bioassay was developed based on community level physiological profiling (CLPP). The efficacy of this assay was evaluated using three wetland water samples, a surface water sample, and two wastewater samples (i.

Inexpensive but Highly Efficient Co-Mn Mixed-Oxide Catalysts for Selective Oxidation of 5-Hydroxymethylfurfural to 2,5-Furandicarboxylic Acid.

A highly active and inexpensive Co-Mn mixed-oxide catalyst was prepared and used for selective oxidation of 5-hydroxymethylfurfural (HMF) into 2, 5-furandicarboxylic acid (FDCA). Co-Mn mixed-oxide catalysts with different Co/Mn molar ratios were prepared through a simple solid-state grinding method-a low-cost and green catalyst preparation method. The activity of these catalysts was evaluated for selective aerobic oxidation of HMF into FDCA in water.

Preparation of activated petroleum coke for removal of naphthenic acids model compounds: Box-Behnken design optimization of KOH activation process.

This study employed Box-Behnken design and response surface methodology to optimize activation parameters for the production of activated petroleum coke (APC) adsorbent from petroleum coke (PC) to achieve highest adsorption capacity for three model naphthenic acids. Activated petroleum coke (APC) adsorbent with a BET surface area of 1726 m/g and total pore volume of 0.85 cc/g was produced at the optimum activation conditions (KOH/coke mass ratio) of 3.

Uptake and phytotoxic effect of benzalkonium chlorides in Lepidium sativum and Lactuca sativa.

Cationic surfactants such as benzalkonium chlorides (BACs) are used extensively as biocides in hospitals, food processing industries, and personal care products. BACs have the potential to reach the rooting zone of crop plants and BACs might thereby enter the food chain. The two most commonly used BACs, benzyl dimethyl dodecyl ammonium chloride (BDDA) and benzyl dimethyl tetradecyl ammonium chloride (BDTA), were tested in a hydroponic system to assess the uptake by and phytotoxicity to lettuce (Lactuca sativa L.

Carbon and Phosphorus Removal from Primary Municipal Wastewater Using Recovered Aluminum.

In this work, recovery of aluminum from coagulated primary sludge and its reuse potential as secondary coagulant were investigated. The recovery process consisted of releasing the particle-bound aluminum from primary sludge by acidification (HCl or HSO), followed by separation using centrifugation for dissolved coagulant recovery. The recovered coagulant was then reused for treating primary wastewater and overall coagulation efficiency was determined.

Low-temperature thermal pre-treatment of municipal wastewater sludge: Process optimization and effects on solubilization and anaerobic degradation.

The present study examines the relationship between the degree of solubilization and biodegradability of wastewater sludge in anaerobic digestion as a result of low-temperature thermal pre-treatment. The main effect of thermal pre-treatment is the disintegration of cell membranes and thus solubilization of organic compounds. There is an established correlation between chemical oxygen demand (COD) solubilization and temperature of thermal pre-treatment, but results of thermal pre-treatment in terms of biodegradability are not well understood.

Biodegradation of benzalkonium chlorides singly and in mixtures by a Pseudomonas sp. isolated from returned activated sludge.

Bactericidal cationic surfactants such as quaternary ammonium compounds (QACs) are widely detected in the environment, and found at mg kg(-1) concentrations in biosolids. Although individual QACs are amenable to biodegradation, it is possible that persistence is increased for mixtures of QACs with varying structure. The present study evaluated the biodegradation of benzyl dimethyl dodecyl ammonium chloride (BDDA) singly and in the presence of benzyl dimethyl tetradecyl ammonium chloride (BDTA) using Pseudomonas sp.

Anaerobic digestibility of estrogens in wastewater sludge: effect of ultrasonic pretreatment.

Background: Estrogenic compounds have been detected in the secondary effluents and in the biosolids from conventional wastewater treatment plants, which are not designed for their removal. Furthermore, existing limited studies on anaerobic digestibility of estrogens report conflicting results. The objective of the present work was to determine the fate and anaerobic digestibility of estrogenic compounds in various types of sludge including primary sludge (PS), waste activated sludge (WAS), and anaerobically digested sludge (seed).

Degradation of estrone in water and wastewater by various advanced oxidation processes.

A comprehensive study was conducted to determine the relative efficacy of various advanced oxidation processes such as O3, H2O2, UV, and combinations of UV/O3, UV/H2O2 for the removal of estrone (E1) from pure water and secondary effluent. In addition to the parent compound (E1) removal, performance of the advanced oxidation processes was characterized using removal of total organic carbon (TOC), and estrogenicity of the effluent. Although E1 removal was high for all the AOPs, intermediates formed were more difficult to degrade leading to slow TOC removal.

Application of ultraviolet light-emitting diode photocatalysis to remove volatile organic compounds from indoor air.

Unlabelled: Photocatalytic oxidation (PCO) is a promising technology for indoor air purification due to low operating cost, potentially long service life, and low maintenance. Ultraviolet light-emitting diode (UVLED) is a new concept in the field of PCO, which has several advantages over conventional UV light sources. Limited research has been conducted using UVLED PCO for air treatment.

Techno-economic evaluation of ultrasound and thermal pretreatments for enhanced anaerobic digestion of municipal waste activated sludge.

To enhance the anaerobic digestion of municipal waste-activated sludge (WAS), ultrasound, thermal, and ultrasound+thermal (combined) pretreatments were conducted using three ultrasound specific energy inputs (1000, 5000, and 10,000 kJ/kg TSS) and three thermal pretreatment temperatures (50, 70 and 90°C). Prior to anaerobic digestion, combined pretreatments significantly improved volatile suspended solid (VSS) reduction by 29-38%. The largest increase in methane production (30%) was observed after 30 min of 90°C pretreatment followed by 10,000 kJ/kg TSS ultrasound pretreatment.

Simulating the degradation of odor precursors in primary and waste-activated sludge during anaerobic digestion.

Degradation of known odor precursors in sludge during anaerobic digestion was systematically studied and simulated using the Anaerobic Digestion Model Number 1 (ADM1). The degradation of various protein fractions (particulate, soluble, and bound), volatile fatty acids (VFAs), lipids, and amino acids of primary sludge (PS) and waste-activated sludge (WAS) were monitored during anaerobic digestion. The degradation kinetic constants of the odor precursors namely, protein, lipid, and VFAs were determined.