Pinewood nanobiochar: A unique carrier for the immobilization of crude laccase by covalent bonding.

Nanotechnology-inspired biocatalytic systems attracted attention for many applications since nanosized supports for enzyme immobilization can improve efficiency-determining factors e.g. enhancing the surface area and loading capacity and reducing the mass transfer resistance. Among the nanomaterials, nanobiochar has unique features as a support for enzyme immobilization i.e. high surface to volume ratio, porous structure, and presence of functional groups on its surface. However, the performance of the immobilization is highly dependent on the immobilization conditions and the properties of the enzyme and the support material. In this research, crude laccase was covalently immobilized onto functionalized nanobiochar using a two-step method of diimide-activated amidation. The effect of different parameters was investigated. The optimal conditions were found to be 14 mg/mL of laccase concentration, 5 mg/mL of nanobiochar, 8.2 mM of cross-linker and 3 h of contact time. For investigating the pH, thermal, storage, and operational stability, the sample obtained from the optimized conditions was used. The results showed the higher stability of immobilized laccase against temperature and pH variation compared to free laccase. In addition, immobilized laccase maintained its catalytic performance up to seven cycles of utilization and showed more than 50% of initial activity after two months of room temperature storage.

Ciprofloxacin-metal complexes -stability and toxicity tests in the presence of humic substances.

The co-contamination of ciprofloxacin (CIP) with metal ions results in alteration of CIP mobility, antimicrobial activity and distribution/development of the antibiotic-resistance genes. In this study, the stability of five CIP-Me complexes [Me = Al(III), Co(II), Cu(II), Fe(III), Mg] was investigated in the presence of humic substances (HS) at two temperatures 18 ±â€¯2 °C and 4 ±â€¯1 °C for seven days period. The most stable complexes were CIP-Al, CIP-Cu, and CIP-Co with the stability constants (K) at 18 °C 35.5 ±â€¯1.4 11.5 ±â€¯1.5 and 11.7 ±â€¯1.5 respectively. At lower temperature (4 °C), the stability constants decreased: 1-fold for CIP-Al, 14-fold for CIP-Co and 2-fold for CIP-Cu. The presence of humic substances decreased the stability of complexes. The chemical reactions of Fe3+ in water at circumneutral pH resulted in stability alteration. The formation of CIP-Mg complexes at lower temperatures and in the presence of HS was limited. In ultrapure water, CIP-Me complexes exhibit higher toxicity towards Gram-negative Enterobacter aeruginosa (ranged between 0.125 and 0.5 µg/ml). However, the presence of HS reduced the antimicrobial activity of CIP-Me complexes by at least 2-fold. Gram-positive representative, Bacillus subtilis was not affected by the presence of metal ions and/or HS. The toxicity toward B. subtilis for the complexes was equal to toxicity of CIP alone (MIC = 0.25 µg/ml). This suggested the different susceptibility to CIP and its complexes.

Removal of pharmaceutical compounds in water and wastewater using fungal oxidoreductase enzymes.

Due to recalcitrance of some pharmaceutically active compounds (PhACs), conventional wastewater treatment is not able to remove them effectively. Therefore, their occurrence in surface water and potential environmental impact has raised serious global concern. Biological transformation of these contaminants using white-rot fungi (WRF) and their oxidoreductase enzymes has been proposed as a low cost and environmentally friendly solution for water treatment. The removal performance of PhACs by a fungal culture is dependent on several factors, such as fungal species, the secreted enzymes, molecular structure of target compounds, culture medium composition, etc. In recent 20 years, numerous researchers tried to elucidate the removal mechanisms and the effects of important operational parameters such as temperature and pH on the enzymatic treatment of PhACs. This review summarizes and analyzes the studies performed on PhACs removal from spiked pure water and real wastewaters using oxidoreductase enzymes and the data related to degradation efficiencies of the most studied compounds. The review also offers an insight into enzymes immobilization, fungal reactors, mediators, degradation mechanisms and transformation products (TPs) of PhACs. In brief, higher hydrophobicity and having electron-donating groups, such as amine and hydroxyl in molecular structure leads to more effective degradation of PhACs by fungal cultures. For recalcitrant compounds, using redox mediators, such as syringaldehyde increases the degradation efficiency, however they may cause toxicity in the effluent and deactivate the enzyme. Immobilization of enzymes on supports can enhance the performance of enzyme in terms of reusability and stability. However, the immobilization strategy should be carefully selected to reduce the cost and enable regeneration. Still, further studies are needed to elucidate the mechanisms involved in enzymatic degradation and the toxicity levels of TPs and also to optimize the whole treatment strategy to have economical and technical competitiveness.

Aerobic Biodegradation of OCDD by P. Mendocina NSYSU: Effectiveness and Gene Inducement Studies.

The goals of this study were to assess the effectiveness of (1) enhancing octachlorinated dibenzo-p-dioxin (OCDD) biodegradation under aerobic conditions by Pseudomonas mendocina NSYSU (P. Mendocina NSYSU) with the addition of lecithin, and (2) inducing OCDD ring-cleavage genes by pentachlorophenol (PCP) and OCDD addition. P. Mendocina NSYSU could biodegrade OCDD via aerobic cometabolism and lecithin was used as a primary substrate. Approximately 74 and 67% of OCDD biodegradation was observed after 60 days of incubation with lecithin and glucose supplement, respectively. Lecithin was also used as the solubilization additive resulting in OCDD solubilization and enhanced bioavailability of OCDD to P. Mendocina NSYSU. Two intradiol and extradiol ring-cleavage dioxygenase genes (Pmen_0474 and Pmen_2526) were identified from gene analyses. Gene concentration was significantly enhanced after the inducement by PCP and OCDD. Higher gene inducement efficiency was obtained using PCP as the inducer, and Pmen_2526 played a more important role in OCDD biodegradation.

Degradation of chlortetracycline using immobilized laccase on Polyacrylonitrile-biochar composite nanofibrous membrane.

The continuous release of antibiotic compounds through wastewater effluent into environment has raised concerns about their potential problems for different organisms. Enzymatic degradation with laccase is a green option for removal of pharmaceutical compounds from aqueous media. In this study, laccase was immobilized onto homemade Polyacrylonitrile-biochar composite nanofibrous membrane and the obtained biocatalyst was employed for removal of chlortetracycline, a widely used antibiotic, from aqueous media in continuous mode. The results showed that the immobilized laccase has improved storage, temperature and pH stability compared to free laccase. Also, it retained more than 50% of its initial activity after 7cycles of ABTS oxidation which indicated improved enzyme reusability. Finally, while using immobilized laccase for degradation of chlortetracycline in continuous mode exhibited 58.3%, 40.7% and 22.6% chlortetracycline removal efficiency at flux rates of 1, 2 and 3mL/h∙cm2.

Immobilized laccase on oxygen functionalized nanobiochars through mineral acids treatment for removal of carbamazepine.

Biocatalytic treatment with oxidoreductase enzymes, especially laccases are an environmentally benign method for biodegradation of pharmaceutical compounds, such as carbamazepine to less harmful compounds. However, enzymes are required to be immobilized on supports to be reusable and maintain their activity. Functionalization of support prior to immobilization of enzyme is highly important because of biomolecule-support interface on enzyme activity and stability. In this work, the effect of oxidation of nanobiochar, a carbonaceous material produced by biomass pyrolysis, using HCl, H2SO4, HNO3 and their mixtures on immobilization of laccase has been studied. Scanning electron microscopy indicated that the structure of nanobiochars remained intact after oxidation and Fourier transform infrared spectroscopy confirmed the formation of carboxylic groups because of acid treatment. Titration measurements showed that the sample treated with H2SO4/HNO3 (50:50, v/v) had the highest number of carboxylic groups (4.7mmol/g) and consequently the highest efficiency for laccase immobilization. Additionally, it was observed that the storage, pH and thermal stability of immobilized laccase on functionalized nanobiochar was improved compared to free laccase showing its potential for continuous applications. The reusability tests towards oxidation of 2, 2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) showed that the immobilized laccase preserved 70% of the initial activity after 3cycles. Finally, using immobilized laccase for degradation of carbamazepine exhibited 83% and 86% removal in spiked water and secondary effluent, respectively.

Adsorption study of environmentally relevant concentrations of chlortetracycline on pinewood biochar.

The presence of pharmaceutically active compounds (PhACs) in water and wastewater has raised concerns because of potential environmental impacts and thus their removal is of high importance. The adsorption behavior of chlortetracycline (CTC) from aqueous solution on raw and activated pinewood biochar was studied at 298 K. The effect of initial pH of the solution was studied by performing the experiment at three different pHs (1, 5 and 9). At each pH, CTC showed varied electrostatic charge (+1, 0 and -1, respectively) which affected its adsorption. The results indicated that CTC followed Langmuir isotherm and the related parameters were calculated. Also, it was observed that the maximum adsorption occurred at pH1. The adsorption capacity of CTC for raw and activated biochar was at least 2.1 and 208.3mg/g adsorbent, respectively. The characteristics of biochars were studied using zeta potential analyzer, laser size analyzer and scanning electron microscopy (SEM). The results showed that raw and activated biochars are promising candidates for removal of CTC from water due to the acidic character of pinewood that can result in better interaction with ionizable compounds at lower pHs.

Biopolymer Production Kinetics of Mixed Culture Using Wastewater Sludge as a Raw Material and the Effect of Different Cations on Biopolymer Applications in Water and Wastewater Treatment.

Thirteen extracellular polymeric substances (EPS) producing bacterial strains were cultivated (as mixed culture) in the sterilized sludge (suspended solids of 25 g/L) and the batch fermentation was carried out. Mixed culture revealed a high specific growth rate of 0.35/hr. The EPS production rate was higher up to 24 hours, which gradually decreased with further incubation. The kinetic estimates demonstrated growth-associated EPS production. Broth EPS revealed higher flocculation activity when combined with different cations (Ca(2+), Mg(2+), Fe(3+), and Al(3+)) in river water (≥90%), municipal wastewater (≥90%), and brewery wastewater (≥80%), respectively. A low dose (5 to 40 mg/L) of trivalent cations was required to achieve higher flocculation compared to the divalent cations (50 to 250 mg/L). Flocculation performance of EPS was comparable to Magnafloc-155 (chemical polymer) and, hence, it could be used as a flocculant.

Membrane processes for removal of pharmaceutically active compounds (PhACs) from water and wastewaters.

Pharmaceutically active compounds (PhACs), which find their way easily into the water sources, are emerging as a major concern for drinking water quality and aquatic species. Therefore, their removal from water sources is a priority from environmental point of view. During the past decade, different methods including membrane separation, adsorption systems and chemical transformation have been evaluated for removal of these compounds. This paper reviews different aspects of PhAC removal by using membrane separation processes, as they have been conventionally known to show high potential in the production of superior quality drinking and industrial water. In brief, osmosis membranes can efficiently remove almost all PhACs though its operational cost is relatively high and nanofiltration (NF) membranes are highly influenced by electrostatic and hydrophobic interaction. Moreover, the efficiency of membrane bioreactors (MBRs) is difficult to predict due to the complex interaction of compounds with microorganisms. To improve the performance and robustness of membrane technology, it is suggested to combine membranes with other systems, such as activated carbon and enzymatic degradation.

Anaerobic digestion of ultrasonicated sludge at different solids concentrations - Computation of mass-energy balance and greenhouse gas emissions.

Two cases of anaerobic digestion (AD) of sludge, namely (i) with pre-treatment and (ii) without pre-treatment, were assessed using mass-energy balance and the corresponding greenhouse gas (GHG) emissions. For a digestion period of 30 days, volatile solids degradation of the control sludge and the ultrasonicated secondary sludge was 51.4% and 60.1%, respectively. Mass balance revealed that the quantity of digestate required for dewatering, transport and land application was the lowest (20.2 × 10(6) g dry sludge/day) for ultrasonicated secondary sludge at 31.4 g TS/L. Furthermore, for ultrasonicated secondary sludge at 31.4 g TS/L, the maximum net energy (energy output - energy input) of total dry solids (TDS) was 7.89 × 10(-6) kWh/g and the energy ratio (output/input) was 1.0. GHG emissions were also reduced with an increase in the sludge solids concentration (i.e., 40.0 g TS/L < 30.0 g TS/L < 20.0 g TS/L). Ultrasonication pre-treatment proved to be efficient and beneficial for enhancing anaerobic digestion efficiency of the secondary sludge when compared to the primary and mixed sludge.

Cheese whey: A potential resource to transform into bioprotein, functional/nutritional proteins and bioactive peptides.

The byproduct of cheese-producing industries, cheese whey, is considered as an environmental pollutant due to its high BOD and COD concentrations. The high organic load of whey arises from the presence of residual milk nutrients. As demand for milk-derived products is increasing, it leads to increased production of whey, which poses a serious management problem. To overcome this problem, various technological approaches have been employed to convert whey into value-added products. These technological advancements have enhanced whey utilization and about 50% of the total produced whey is now transformed into value-added products such as whey powder, whey protein, whey permeate, bioethanol, biopolymers, hydrogen, methane, electricity bioprotein (single cell protein) and probiotics. Among various value-added products, the transformation of whey into proteinaceous products is attractive and demanding. The main important factor which is attractive for transformation of whey into proteinaceous products is the generally recognized as safe (GRAS) regulatory status of whey. Whey and whey permeate are biotransformed into proteinaceous feed and food-grade bioprotein/single cell protein through fermentation. On the other hand, whey can be directly processed to obtain whey protein concentrate, whey protein isolate, and individual whey proteins. Further, whey proteins are also transformed into bioactive peptides via enzymatic or fermentation processes. The proteinaceous products have applications as functional, nutritional and therapeutic commodities. Whey characteristics, and its transformation processes for proteinaceous products such as bioproteins, functional/nutritional protein and bioactive peptides are covered in this review.

Green and energy-efficient methods for the production of metallic nanoparticles.

In the last decade, researchers paid great attention to the concept of "Green Chemistry", which aims at development of efficient methods for the synthesis of nanoparticles (NPs) in terms of the least possible impact on human life and environment. Generally, several reagents including precursors, reducing agents, stabilizing agents and solvents are used for the production of NPs and in some cases, energy is needed to reach the optimum temperature for reduction. Therefore, to develop a green approach, researchers had the opportunity to investigate eco-friendly reagents and new energy transfer techniques. In order to substitute the harmful reagents with green ones, researchers worked on different types of saccharides, polyols, carboxylic acids, polyoxometalates and extracts of various plants that can play the role of reducers, stabilizers or solvents. Also, there are some reports on using ultraviolet (UV), gamma and microwave irradiation that are capable of reducing and provide uniform heating. According to the literature, it is possible to use green reagents and novel energy transfer techniques for production of NPs. However, these new synthesis routes should be optimized in terms of performance, cost, product quality (shape and size distribution) and scale-up capability. This paper presents a review on most of the employed green reagents and new energy transfer techniques for the production of metallic NPs.

Extracellular polymeric substances of bacteria and their potential environmental applications.

Biopolymers are considered a potential alternative to conventional chemical polymers because of their ease of biodegradability, high efficiency, non-toxicity and non-secondary pollution. Recently, extracellular polymeric substances (EPS, biopolymers produced by the microorganisms) have been recognised by many researchers as a potential flocculent for their applications in various water, wastewater and sludge treatment processes. In this context, literature information on EPS is widely dispersed and is very scarce. Thus, this review marginalizes various studies conducted so far about EPS nature-production-recovery, properties, environmental applications and moreover, critically examines future research needs and advanced application prospective of the EPS. One of the most important aspect of chemical composition and structural details of different moieties of EPS in terms of carbohydrates, proteins, extracellular DNA, lipid and surfactants and humic substances are described. These chemical characteristics of EPS in relation to formation and properties of microbial aggregates as well as degradation of EPS in the matrix (biomass, flocs etc) are analyzed. The important engineering properties (based on structural characteristics) such as adsorption, biodegradability, hydrophilicity/hydrophobicity of EPS matrix are also discussed in details. Different aspects of EPS production process such as bacterial strain maintenance; inoculum and factors affecting EPS production were presented. The important factors affecting EPS production include growth phase, carbon and nitrogen sources and their ratio, role of other nutrients (phosphorus, micronutrients/trace elements, and vitamins), impact of pH, temperature, metals, aerobic versus anaerobic conditions and pure and mixed culture. The production of EPS in high concentration with high productivity is essential due to economic reasons. Therefore, the knowledge about all the aspects of EPS production (listed above) is highly essential to formulate a logical and scientific basis for the research and industrial activities. One of the very important issues in the production/application/biodegradation of EPS is how the EPS is extracted from the matrix or a culture broth. Moreover, EPS matrix available in different forms (crude, loosely bound, tightly bound, slime, capsular and purified) can be used as a bioflocculant material. Several chemical and physical methods for the extraction of EPS (crude form or purified form) from different sources have been analyzed and reported. There is ample information available in the literature about various EPS extraction methods. Flocculability, dewaterability and biosorption ability are the very attractive engineering properties of the EPS matrix. Recent information on important aspects of these properties qualitatively as well as quantitatively has been described. Recent information on the mechanism of flocculation mediated by EPS is presented. Potential role of EPS in sludge dewatering and biosorption phenomenon has been discussed in details. Different factors influencing the EPS ability to flocculate and dewaterability of different suspensions have been included. The factors considered for the discussion are cations, different forms of EPS, concentration of EPS, protein and carbohydrate content of EPS, molecular weight of EPS, pH of the suspension, temperature etc. These factors were selected for the study based upon their role in the flocculation and dewatering mechanism as well the most recent available literature findings on these factors. For example, only recently it has been demonstrated that there is an optimum EPS concentration for sludge flocculation/dewatering. High or low concentration of EPS can lead to destabilization of flocs. Role of EPS in environmental applications such as water treatment, wastewater flocculation and settling, colour removal from wastewater, sludge dewatering, metal removal and recovery, removal of toxic organic compounds, landfill leachate treatment, soil remediation and reclamation has been presented based on the most recent available information. However, data available on environmental application of EPS are very limited. Investigations are required for exploring the potential of field applications of EPS. Finally, the limitations in the knowledge gap are outlined and the research needs as well as future perspectives are highlighted.

Mixed culture of Kluyveromyces marxianus and Candida krusei for single-cell protein production and organic load removal from whey.

The study was conducted to evaluate the potential of mixed culture of Kluyveromyces marxianus and Candida krusei to enhance COD removal efficiency, minimize contamination at extreme conditions (high temperature 40°C and low pH 3.5) during batch and continuous aerobic fermentation and to obtain improved quality single-cell protein (SCP) using whey as substrate. The batch fermentation of mono-culture and mixed culture result showed that the mixed culture resulted in 8.8% higher COD removal efficacy with 19% higher biomass yield and 33% increased productivity. The maximum COD removal 80.2% (including residual protein) was obtained at 24h HRT with biomass productivity of 0.17 g/L/h; however, maximum biomass productivity of 0.38 g/L/h and 34% COD removal were obtained at 6h HRT. The results showed that the mixed culture of acid resistance and thermo-tolerant yeasts was a potential way to produce SCP (animal feed) and simultaneous COD removal under extreme operating conditions.

Photocatalytic degradation of carbamazepine in wastewater by using a new class of whey-stabilized nanocrystalline TiO2 and ZnO.

Nanoscale photocatalysts have attracted much attention due to their high surface area to volume ratios. However, due to extremely high reactivity, TiO2 and ZnO nanoparticles prepared using different methods tend to either react with surrounding media or agglomerate, resulting in the formation of much larger flocs and significant loss in reactivity. This work investigates the photocatalytic degradation of carbamazepine (CBZ), a persistent pharmaceutical compound from wastewater (WW) using TiO2 and ZnO nanoparticles prepared in the presence of a water-soluble whey powder as stabilizer. The TiO2 and ZnO nanoparticles prepared in the presence of whey stabilizer displayed much less agglomeration and greater degradation power than those prepared without a stabilizer. Higher photocatalytic degradation of carbamazepine was observed (100%) by using whey stabilized TiO2 nanoparticles with 55 min irradiation time as compared to ZnO nanoparticles (92%). The higher degradation of CBZ in wastewater by using TiO2 nanoparticles as compared to ZnO nanoparticles was due to formation of higher photo-generated holes with high oxidizing power of TiO2. The photocatalytic capacity of ZnO anticipated as similar to that of TiO2 as it has the same band gap energy (3.2 eV) as TiO2. However, in the case of ZnO, photocorrosion frequently occurs with the illumination of UV light and this phenomenon is considered as one of the main reasons for the decrease of ZnO photocatalytic activity in aqueous solutions. Further, the estrogenic activity of photocatalyzed WW sample with CBZ and its by-products was carried out by yeast estrogen screen (YES) assay method. Based upon the YES test results, none of the samples showed estrogenic activity.

Recovery of residual soluble protein by two-step precipitation process with concomitant COD reduction from the yeast-cultivated cheese whey.

The present study was conducted to recover the residual soluble protein after cultivation of yeast (K. marxianus) in cheese whey. Cheese whey continuous fermentation with cell recycle system was carried out at 40 °C and pH 3.5. The yeast biomass was separated from the fermented broth by centrifugation and residual soluble protein from fermented whey supernatant was precipitated by heat treatment (at 100 °C, pH 4.5 and 10 min incubation). The maximum soluble protein recovery up to 53 % was achieved at pH 4.5 with 54 % residual COD removal. However, gravity sedimentable precipitates were obtained at pH 3.5 with 47 % protein recovery. Therefore, the reactor (scale up) study was conducted at pH 3.5 with agitation, which resulted in 68 % of residual soluble protein recovery and simultaneously residual COD removal of 62 %. Further precipitation/coagulation of soluble protein was also evaluated using carboxymethylcellulose (CMC) and then two precipitation (thermal followed by CMC precipitation) processes were combined to increase the protein precipitation, which finally reached up to 81 % of total soluble protein recovery from the supernatant. This optimized process could be applied to recover the residual protein left after fermentation of cheese whey without centrifugation.

Permeabilization of Kluyveromyces marxianus with mild detergent for whey lactose hydrolysis and augmentation of mixed culture.

Cheese whey is a by-product of cheese-manufacturing industries, and the utilization of whey is a challenging problem either to use it or dispose it, because only few microorganisms can metabolize the whey lactose. Enzymatic hydrolysis of whey lactose to glucose and galactose by ß-galactosidase is the approach for biotechnological application. Kluyveromyces marxianus cells were permeabilized with non-toxic, biodegradable, anionic detergent N-lauroyl sarcosine (N-LS) for the enzyme activity. The permeabilization process parameters (N-LS concentration, solvent volume, temperature and incubation time) were optimized. The maximum ß-galactosidase activity of 1,220 IU/g dry weight was obtained using permeabilized cells under optimized conditions. Moreover, viability of the permeabilized cells was also evaluated, which showed that cells were alive; however, viability was reduced by two log cycles. The permeabilized cells were evaluated for whey lactose hydrolysis. The maximum lactose hydrolysis of 91% was observed with 600 mg (dry cell weight/100 mL) in whey powder (5% w/v) solution at 180-min incubation, pH 6.5 and 30 °C. Further, the hydrolyzed whey was evaluated for amelioration of growth of non-lactose-consuming yeast Saccharomyces cerevisiae. S. cerevisiae was able to grow in hydrolyzed whey simultaneously with K. marxianus. The study confirmed that N-LS could be used to permeabilize K. marxianus cells to make available the enzyme activity.

Simultaneous single-cell protein production and COD removal with characterization of residual protein and intermediate metabolites during whey fermentation by K. marxianus.

Cheese whey fermentation with Kluyveromyces marxianus was carried out at 40 °C and pH 3.5 to examine simultaneous single-cell protein production and chemical oxygen demand (COD) removal, determine the fate of soluble whey protein and characterize intermediate metabolites. After 36 h of batch fermentation, the biomass concentration increased from 2.0 to 6.0 g/L with 55 % COD reduction (including protein), whereas soluble whey protein concentration decreased from 5.6 to 4.1 g/L. It was confirmed through electrophoresis (SDS-PAGE) that the fermented whey protein was different from native whey protein. HPLC and GC-MS analysis revealed a change in composition of organic compounds post-fermentation. High inoculum concentration in batch fermentation resulted in an increase in biomass concentration from 10.3 to 15.9 g/L with 80 % COD reduction (including protein) within 36 h with residual protein concentration of 4.5 g/L. In third batch fermentation, the biomass concentration increased from 7.3 to 12.4 g/L with 71 % of COD removal and residual protein concentration of 4.3 g/L after 22 h. After 22 h, the batch process was shifted to a continuous process with cell recycle, and the steady state was achieved after another 60 h with biomass yield of 0.19 g biomass/g lactose and productivity of 0.26 g/L h. COD removal efficiency was 78-79 % with residual protein concentration of 3.8-4.2 g/L. The aerobic continuous fermentation process with cell recycle could be applied to single-cell protein production with substantial COD removal at low pH and high temperature from cheese whey.

Analysis and advanced oxidation treatment of a persistent pharmaceutical compound in wastewater and wastewater sludge-carbamazepine.

Pharmaceutically active compounds (PhACs) are considered as emerging environmental problem due to their continuous input and persistence to the aquatic ecosystem even at low concentrations. Among them, carbamazepine (CBZ) has been detected at the highest frequency, which ends up in aquatic systems via wastewater treatment plants (WWTPs) among other sources. The identification and quantification of CBZ in wastewater (WW) and wastewater sludge (WWS) is of major interest to assess the toxicity of treated effluent discharged into the environment. Furthermore, WWS has been subjected for re-use either in agricultural application or for the production of value-added products through the route of bioconversion. However, this field application is disputable due to the presence of these organic compounds and in order to protect the ecosystem or end users, data concerning the concentration, fate, behavior as well as the perspective of simultaneous degradation of these compounds is urgently necessary. Many treatment technologies, including advanced oxidation processes (AOPs) have been developed in order to degrade CBZ in WW and WWS. AOPs are technologies based on the intermediacy of hydroxyl and other radicals to oxidize recalcitrant, toxic and non-biodegradable compounds to various by-products and eventually to inert end products. The purpose of this review is to provide information on persistent pharmaceutical compound, carbamazepine, its ecological effects and removal during various AOPs of WW and WWS. This review also reports the different analytical methods available for quantification of CBZ in different contaminated media including WW and WWS.