Progress in Analytical Methods of Halogenated Disinfection By-Products

Ensuring the health and safety of drinking water is crucial for both nations and their citizens.Since the 20th century,the disinfection of drinking water,effectively controlling pathogens in water sources,has become one of the significant advances in public health.However,the disinfectants used in the process,such as chlorine and chlorine dioxide,react with natural organic matter in the water to produce disinfection by-products(DBPs).Most of these DBPs contain chlorine,and if the source water contains bromine or iodine,brominated or iodinated DBPs,collectively referred to as Halogenated disinfection byproducts(X-DBPs),are formed.Numerous studies have found that X-DBPs pose potential risks to human health and the environment,leading to widespread concern.Mass spectrometry has become an important means of discovering new types of X-DBPs.This paper focuses on the study of methods for analyzing X-DBPs in drinking water using mass spectrometry.

Health Risk Assessment of Employees Exposed to Chlorination By-products of Recreational Water in Large Amusement Parks in Shanghai

Objective Chlorination is often used to disinfect recreational water in large amusement parks;however,the health hazards of chlorination disinfection by-products(DBPs)to occupational populations are unknown.This study aimed to assess the exposure status of chlorinated DBPs in recreational water and the health risks to employees of large amusement parks.Methods Exposure parameters of employees of three large amusement parks in Shanghai were investigated using a questionnaire.Seven typical chlorinated DBPs in recreational water and spray samples were quantified by gas chromatography,and the health risks to amusement park employees exposed to chlorinated DBPs were evaluated according to the WHO's risk assessment framework.Results Trichloroacetic acid,dibromochloromethane,bromodichloromethane,and dichloroacetic acid were detected predominantly in recreational water.The carcinogenic and non-carcinogenic risks of the five DBPs did not exceed the risk thresholds.In addition,the carcinogenic and non-carcinogenic risks of mixed exposure to DBPs were within the acceptable risk limits.Conclusion Typical DBPs were widely detected in recreational water collected from three large amusement parks in Shanghai;however,the health risks of DBPs and their mixtures were within acceptable limits.

Effects of molasses on the fermentation characteristics of mixed silage prepared with rice straw, local vegetable by-products and alfalfa in Southeast China

This experiment was conducted to study the effect of molasses on the fermentation characteristics of mixed silage ensiled rice straw and vegetable by-products with alfalfa.Mixture（202 g kg^-1 dry matter（DM））consisting of rice straw,broccoli residue and alfalfa at the ratio of 5：4：1 was ensiled with three experimental treatments：（1）no additives（control）;（2）molasses at 2.5%（M1）;（3）molasses at 5%（M2）on a fresh matter basis of mixture,respectively.All treatments were packed into laboratory-scale silos,and three silos per treatment were sampled on days 1,3,5,14 and 30.The result showed that the p H value of all mixed silages decreased gradually with the time of ensiling except for the control silage,in which a significant increase（P〈0.05）on day 30 occurred.The lactic acid content increased gradually with the time of ensiling and reached the highest value on day 14,and a marked decrease（P〈0.05）was found in the control silage on day 30.The changes of acetic acid content showed similar pattern with lactic acid content.A trace amount of propionic and butyric acid contents were found in the three mixed silages during the fermentation period.Comparing to the control,M1 and M2 treatments improved the fermentation quality of mixed silages as indicated by higher（P〈0.05）lactic acid contents and lower（P〈0.05）p H and ammonia-N contents.The Flieg points also showed that M1 and M2 silages were well preserved,whereas the control silage had a bad quality.Overall,the findings of this study suggested that adding molasses could improve fermentation quality of mixed silage,and M1 was more suitable for practical application.

Nitric acid pressure leaching of limonitic laterite ores:Regeneration of HNO3 and simultaneous synthesis of fibrous CaSO4·2H2O by-products

An innovative technology,nitric acid pressure leaching of limonitic laterite ores,was proposed by our research team.The HNO3 regeneration is considerable significance for the improvement of the proposed technology and its commercial application,but it has not been systematically investigated.Herein,regenerating HNO3 from Ca(NO3)2 solution with low-cost H2SO4,and simultaneous synthesis of fibrous CaSO4·2H2O by-products were studied.As a theoretical basis,the solubility of CaSO4·2H2O in HNO3 medium is studied.It is concluded that the solubility of CaSO4·2H2O increases with increasing temperature or increasing HNO3 concentration,which has considerable guiding significance for the subsequent experimental research and analysis.Then,the effects of various factors on the residual Ca^2+ concentration of filtrate,the regenerated HNO3 concentration and the morphology of synthesized products are investigated using ICP-AES and SEM.And the effect mechanism is also analyzed.The results indicate the regenerated HNO3 concentration reaches 116 g/L with the residual Ca^2+ concentration being 9.7 g/L at the optimum conditions.Moreover,fibrous CaSO4·2H2O by-products with high aspect ratios(length,406.32μm;diameter,14.71μm;aspect ratio,27.62)can be simultaneously synthesized.

Simultaneous Control of Microorganisms and Disinfection By-products by Sequential Chlorination

Objective To introduce a new sequential chlorination disinfection process in which short-term free chlorine and chloramine are sequentially added. Methods Pilot tests of this sequential chlorination were carried out in a drinking water plant. Results The sequential chlorination disinfection process had the same or better efficiency on microbe （including virus） inactivation compared with the free chlorine disinfection process. There seemed to be some synergetic disinfection effect between free chlorine and monochloramine because they attacked different targets. The sequential chlorination disinfection process resulted in 35.7%-77.0% TTHM formation and 36.6%-54.8% THAA5 formation less than the free chlorination process. The poorer the water quality was, the more advantage the sequential chlorination disinfection had over the free chlorination. Conclusion This process takes advantages of free chlorine＇s quick inactivation of microorganisms and chloramine＇s low disinfection by-product （DBP） yield and long-term residual effect, allowing simultaneous control of microbes and DBPs in an effective and economic way.

Removal of disinfection by-products formation potential by biologically intensified process

The removal of disinfection by-products formation potential(DBPFP) in artificially intensified biological activated carbon(IBAC) process which is developed on the basis of traditional ozone granular activated carbon was evaluated. By IBAC removals of 31% and 68% for THMFP and HAAFP were obtained respectively. Under identical conditions, the removals of the same substances were 4% and 32% respectively only by the granular activated carbon(GAC) process. Compared with GAC, the high removal rates of the two formed potential substances were due to the increasing of bioactivity of the media and the synergistic capabilities of biological degradation cooperating with activated carbon adsorption of organic compounds. A clear linear correlation(R 2=0.9562 and R 2=0.9007) between DOC HAAFP removal rate and Empty Bed Contact Time(EBCT) of IBAC process was observed, while that between THMFP removal rate and EBCT of GAC was R 2=0.9782. In addition certain linear correlations between THMFP, HAAFP and UV 254 (R 2=0.855 and R 2=0.7702) were found for the treated water. For IBAC process there are also more advantages such as long backwashing cycle time, low backwashing intensity and prolonging activated carbon lifetime and so on.

Neem by-products in the fight against mosquito-borne diseases:Biotoxicity of neem cake fractions towards the rural malaria vector Anopheles culicifacies(Diptera:Culicidae)

Objective: To evaluate the ovicidal, larvicidal and adulticidal potential of neem cake fractions of different polarity against the rural malaria vector Anopheles culicifacies(An.culicifacies).Methods: Neem cake fractions' total methanol extract(NTMeOH), total ethyl acetate extract(NTAc OEt), ethyl acetate fraction after repartition with NTMe OH(NRAc OEt),butanol fraction after repartition with NTMeOH(NRBuOH), and aqueous fraction after repartition of NTMeOH(NRH2O) were tested against An. culicifacies eggs, fourth instar larvae and adults.Results: In larvicidal experiments, NTMeOH, NTAcOEt, NRAcOEt, NRBuOH and NRH2O achieved LC50 values of 1.32, 1.50, 1.81, 1.95 and 2.54 mg/L, respectively. All fractions tested at 150 mg/L were able to reduce egg hatchability of more than 50%, with the exception of NTAc OEt and NRAc OEt. In adulticidal assays, NTMeOH, NTAcOEt,NRAcOEt, NRBuOH and NRH2O achieved LC50 values of 3.01, 2.95, 3.23, 3.63 and3.00 mg/L, respectively.Conclusions: Overall, this study suggests that the methanolic fractions of neem cake may be considered as a new and cheap source of highly effective compounds against the rural malaria vector An. culicifacies.

Comprehensive utilization of corn starch processing by-products:A review

Corn is a high starchy cereal crop with the highest production and provides over 85%of the starch produced worldwide.Various by-products,differentiated by technological process features such as steep liquor,corn germ,corn bran,gluten,are created largely during corn starch processing.They are inexpensive,nutrient-rich,and vary widely in chemical composition such as proteins,oils,carbohydrates,and minerals.In an increasingly resource-constrained modern world,the utilization approach of these by-products for non-starch industrial processing is attractive widely considering both nutritive value and economic aspects.In fact,at present,applications of these by-products can often be found in feed,fermentation,nutrient extraction and other industries.For example,protein-rich corn gluten can be used as a good animal feed,and corn germ can be used as a raw material for the high-quality edible oil industry.Undoubtedly,increasing utilization means that these by-products will no longer be treated as waste but will be transformed into high value-added products.In this work,the separation process and chemical composition of several main by-products of the corn starch industry is briefly described,and the application in many industrial fields of these by-products over the last ten years are discussed in particular.This review attempts to summarize all aspects of the application and research of these by-products.For the by-products of the corn starch industry,the most promising way is to be utilized in high value and used to produce high value-added products.According to the characteristics of their chemical composition,they have a better application prospect and research significance in the industries directly related to human beings,such as medicine,green food and health care products.In fact,in recent years,some researchers have recognized this and carried out the research.It is clear fromthese studies that the main issues to be faced nowand in the future are how to produce efficiently while maintaining the quality of the product and using it effectively.The retrospective discussions also provide some ideas for other grain and oilseed crops to be fully utilized.

Enzymatic recovery of glycopeptides from different industrial grades edible bird’s nest and its by-products:nutrient,probiotic and antioxidant activities,and physicochemical characteristics

This study was conducted to recover edible bird’s nest(EBN)hydrolysates from different grades of EBN,including the industrial by-products,using enzymatic treatment.The nutrient,physicochemical properties and antioxidant activities of the recovered hydrolysates at different hydrolysis times were evaluated.Results showed that the recovery yield of enzymatic hydrolysis was above 89%for all grades of EBN and the degree of hydrolysis increased over time.Nitrite content(0.321-0.433 mg/L)was below the permissible tolerance level for all samples.Interestingly,the antioxidant activities(DPPH and ABTS scavenging activities and ferric reducing antioxidant powder(FRAP)activity)were significantly higher(P≤0.05)in hydrolysates recovered from EBN by-products(EBNhC and EBNhD)as compared to the high grade EBN hydrolysates(EBNhA and EBNhB).The in-vitro probiotic activity of EBN and its hydrolysates were examined using the probiotic bacterium Lactobacillus plantarum.Evidently,EBN by-products hydrolysate(EBNhD)recorded the highest number of L.plantarum(1.1×1011 CFU/mL),indicating that low grade EBN has the potential as prebiotic material that promotes probiotic activity.This study demonstrated the concept of using EBN by-products hydrolysates for various applications,such as functional ingredients with enhanced bioactivities,to improve its economic value.

Reduction of Precursors of Chlorination By-products in Drinking Water Using Fluidized-bed Biofilm Reactor at Low Temperature

Objective To investigate the reduction of chlorination by-products （CBPs） precursors using the fluidized-bed biofdm reactor （FBBR）. Methods Reduction of total organic carbon （TOC）, ultraviolet absorbance （UV254）, tfihalomethane （THM） formation potential （THMFP）, haloacetic acid （HAA） formation potential （HAAFP）, and ammonia in FBBR were evaluated in detail. Results The reduction of TOC or UV254 was low, on average 12.6% and 4.7%, respectively, while the reduction of THMFP and HAAFP was significant. The reduction of ammonia was 30%-40% even below 3℃, however, it could quickly rise to over 50% above 3℃. Conclusions The FBBR effectively reduces CBPs and ammonia in drinking water even at low temperature and seems to be a very promising and competitive drinking water reactor for polluted surface source waters, especially in China.

XPS,Chemical Trapping, and DRFTIR Study on Mechanism of By-Products Formation in Selective (AMM)Oxidation of Propylene on MoO_3 and γ-Bi_2MoO_6

XPS and chemical trapping experments with H2, NH3, and CH3I as trapping agents were carried out for studying the adsorption of propylene over MoO3 or r-Bi2MoO6. The results show that the fragmentation of carbon chain takes place during the adsorption of propylene through breaking C -C double bond and C-C bond on Mo2+ and the adjacent lattice oxygen, leading to formation of the oxygen- or nitrogen-containing by-products of C1 and C2 species. Diffuse-Reflection Fourier Transform Infrared (DRFTIR) Spectroscopy was used to study the surface species formed during the chemisorption and reaction of propylene over y-Bi2MoO6 at a lower temperature. The results that C1, C2 adspecies were detected by DRFTIR at 175℃ are consistent with the results of XPS and chemical trapping experiments, whlle the results at 50℃ Grasselli et al.

Removal characteristics of disinfection by-products formation potential by bioaugmentation activated carbon process

The high-active bacteria were screened from 8 dominant bacteria obtained from the natural water body,and then the bioaugmentation activated carbon was formed by hydraulic immobilization of the high-active bacteria. Plant-scale studies on removal characteristics of disinfection by-products formation potentials (DBPFP) by bioaugmentation activated carbon process were conducted for micro-polluted raw water treatment. The results show that the bioaugmentation activated carbon process has adopted better purification efficiency to THMFP and HAAFP than traditional biological activated carbon process,and that average removal efficiencies of THMFP and HAAFP can reach 35% and 39.7% during the test period,increasing by more than 10% compared with traditional biological activated carbon process. The removal efficiencies of THMFP and HAAFP are stable because of the biodegradation of the high-active bacteria and the adsorption of active carbon. The biodegradability of CHCl3 formation potential is better as compared with that of CHCl2Br and CHClBr2 formation potentials among THMFP,and high removal efficiency of CHCl3formation potential is obtained by bioaugmentation degradation of the high-active bacteria. The biodegradability of HAAFP is better in comparison with that of THMFP,and the chemical properties of HAAFP are propitious to adsorption of activated carbon. Thus,HAAFP is on predominance during the competitive removal process with THMFP.

Development of Techniques for Animal Feed from Corn and Their By-Products

Research results concerned （ 1 ） quantification of pH value and contents of ammonia nitrogen, volatile fatty acids （VFAs）, and lactic acid, which were indicators of fermentative quality of corn stover silage and other crop by-product silages ; （2） introduction of methods for analyses of fiber content in feeds such as detergent and enzymatic analyses; （3） determination of digestive characteristics in the tureen by artificial digestion trials （ in vitro and in situ ） ; （ 4 ） evaluation of meat productivity and quality by feeding corn stover silage to beef cattle in feeding experiments and; （5） preparation of feed composition and feeding standards for animals in Jilin Province. These results and methods substantially contributed to stabilization of feed supply as well as an increase in the efficiency of meat production, resulting in sustainable development of livestock management in China.

Study on the Technologic Optimization for Hydrolysis of Silver carp By-products

The hydrolysis process for Silver carp by-products was studied. Protein hydrolysate was prepared with proteolytic enzyme, Alcalase. Hydrolysis conditions were optimized by the regression model of three factors five levels quadratic rotation perpendicular regressive design. The optimum hydrolysis conditions of hydrolyzing the protein of Silver carp by-products were determined to be concentration of enzyme (E/S) 3.33%, pH 8.54, hydrolyzing temperature 58 ℃, reaction time 90 min, concentration of substrate 8%. Nitrogen recovery was more than 75%.

Chemical Composition and Nutritive Value of Agro-Industrial By-Products in Ruminant Nutrition

This study was carried out to determine the chemical composition and in situ degradability of agro-industrial by-products found in Eritrea. Three categories of by-products were evaluated and were the milling industry (wheat bran;WB, short;WS, and middling;WM), brewery (brewers’ dry grain;BDG, hops;BDH, and yeast;BDY) and sesame cakes (sesame cake machine extracted;SCM and manually extracted;SCT). The dry matter (DM) varied between 88.46% in BDY to 92.39% in SCT. The lowest (P < 0.05) crude protein (CP) content was recorded in WM at 10.11% while the highest was from the BDY at 48.20%. The metabolisable energy (ME) value of the agro-industrial by-products ranged from 8.72 to 11.18 MJ per kg DM with the BDH recording the lowest value (P The sesame cakes (SCM and SCT) recorded higher values of 11.17 and 11.18 MJ per kg DM respectively. The SCT recorded the highest ash content at 10.93% followed by BDY at 10.16% with the least being obtained from WM at 2.48%. The ether extract and acid detergent lignin contents were generally low in all cases for all the by-products. Generally, the results indicated that there was no clear pattern in terms of nutrients content amongst the by-products. The in situ DM, organic matter (OM) and CP degradability differed amongst and within the sesame cakes, milling and brewery by-products. The wide variation in chemical composition, DM, OM, CP degradability, and ME obtained from this study offer farmers huge flexibility in formulating rations according to the productive performance of target animals.

Photoelectrocatalytic Oxidation of Ethinylestradiol on a Ti/TiO₂Electrode: Degradation Efficiency and Search for By-Products

The degradation of ethinylestradiol (EE, an orally bio-active estrogen) in an aqueous-methanolic solution using a Ti/TiO2 thin-film electrode and UV radiation (a photoelectrocatalytic system) was evaluated. Hence, HPLC/UV analysis shows that EE (at 0.34 mmol) is totally consumed after 30 minutes of exposure to the photoelectrocatalytic system in the presence of Na2SO4 (0.1 mol·L-1) and with an applied bias potential of +1.0 V versus the Ag/AgCl reference electrode. Moreover, monitoring by direct infusion electrospray ionization mass spectrometry (ESI-MS) and SPME-GC/ MS (solid phase microextraction coupled with gas chromatography-mass spectrometry) reveals that apparently no degradation products are formed under these conditions. Hence, this study demonstrates that the photoelectrocatalytic system can be efficiently used to promote the complete degradation (and likely mineralization) of this hormone under these conditions.

Innovations in Value-Addition of Agricultural By-Products in Uganda

The purpose of this review was to profile the existing innovations in the value addition of agricultural by-products and suggest innovations that could yield more value-added products from the available agricultural by-products in Uganda. These by-products were from crops, livestock, fish and forestry sub-sectors. The review indicated 7.8 million tons from the crops’ subsector, 6.69 million skins and hides, 2280 million tons of cow dung and 390,550 tons of chicken dung from the livestock subsector, 36,000 tons from the fish subsector and 440,000 m3 of sawdust and offcuts from the forestry sub-sector. Current innovations in value-addition of agricultural by-products included the making of briquettes, organic fertilizers, biogas, biochar, pellets and organic pesticides from the crop subsector. Cow dung from the livestock is used for plastering walls of houses, used as fertilizer and used for the production of biogas. Chicken droppings are as well used as fertilizer and for production of biogas. Fish frames and skins are mainly consumed in smoked form whereas trimmings are usually rolled into fish balls and then fried for people to eat while the fats are used for frying the fish balls. Sawdust has been mixed with cement to make wood-cement composite bricks that reduce the overall weight of the building. It is also being used as feed in the Indigenous Micro-Organisms (IMO) technology in the production of pigs. Proposed innovations include the use of bones to produce soft tissue, buttons, knife handles and bone meal. Blood can be used in making adhesives and fertilizers while fish oil is a major dietary source of long chain omega-3 polyunsaturated fatty acids and so can be utilized to enrich different food products.

High Resolution Mass Spectrometry Elucidation of Captopril’s Ozonation and Chlorination By-Products

The article evaluated the degradation of the captopril in aqueous solution after ozonation and chlorination. The process was continuously monitored focusing on the identification, mass spectrometry and elucidation of its by-products by applying direct infusion and high performance liquid chromatography, electrospray ionization high resolution mass spectrometry, in the negative ion mode. The cytotoxicity of its by-products solutions were evaluated with 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. It was observed through that after 30 min of ozonation and chlorination, there was complete oxidation of captopril, i.e., 100% removal efficiency. At these conditions, the rate of mineralization, by total organic carbon, was only 7.63% for ozonation and 6.40% for chlorination, evidencing the formation of degradation by-products. Ten captopril by-products were identified and their respective chemical structures elucidations are proposed. The treated samples and their by-products were nontoxic to HepG2 cells by MTT assay.

Effects of Replacing Fishmeal with Animal By-products Meal Supplementation in Diets on the Growth and Nutrient Utilization of Mangrove Red Snapper

A feeding trial was conducted for 75 d to evaluate the nutritive value of a mixture of animal by-products （MAB） as a possible protein source in diets for juvenile mangrove red snapper, Lutjanus argentimaculatus （mean initial body weight, 30 g）. Fish were fed one of five isonitrogenous diets （40% crude protein） replacing 0, 25% （MAB25）, 50% （MAB50）, 75% （MAB75） and 100% （MAB100） of fish meal protein with similar percentages of MAB. The MAB consisted of 25% cow liver meal, 20% leather meal, 20% meat and bone meal, 15% blood meal, 10% APC （poultry feather meal）, 8% poultry manure dried, 1.5% choline and 0.5% chromic oxide. After 75 d of feeding, fish fed with diets MAB50, MAB75 and MABI00 exhibited significantly lower growth performance than that of fish fed with control and MAB25 diets. The optimum level of MAB was estimated to be 23%. Replacement of fish meal by MAB23% showed the following performance： maximum weight gain, 510%; SGR, 2.39% and FCE, 2.83%. The MAB substitution up to 75% of fish meal protein in diets did not show differences in apparent protein digestibility （83.6% for MAB25, 79.2% for MAB50, 78.7% for MAB75） compared with control （83.4%）, whereas in MABI00 group digestibility （65.3%） was significantly lower than in other groups. The apparent phosphorus absorption of test diet groups was significantly higher （37.1% for MAB25, 28.5% for MABS0, 55.6% for MAB75 and 54.5% for MABI00） than that of control （1 1.2%）. The levels of protein and ash in the whole body, carcass and viscera increased as MAB substitution in diets increased, whereas lipids and moisture remained consistent among all treatment groups. These results showed that approximately 23% of fish meal protein could be replaced by a mixture of animal by-products for juvenile snapper growing from 30 g to 167 g in 75 d without compromising growth performance and feed efficiency.

Mercury Speciation of Flue Gas Desulphurization By-Products in Coal-Fired Power Plants in China

The aim of this study was to develop and examine the morphology and distribution of mercury (Hg) in flue gas desulfurization (FGD) by-product. Mercury in the coal of coal-fired power plants is concentrated in the by-products of desulfurization process, and it is widely used as an additive in cement, building materials and other industries. Due to the different stability of various forms of mercury in the environment, subsequent use of products containing desulfurization by-product additives will continue to be released into the environment, endangering human health. Therefore, it is very necessary to study the form and distribution of mercury in the by-products of desulfurization in coal-fired power plants to provide a theoretical basis for subsequent harmless treatment. For content and morphology of mercury analysis, 1 sample of dry FGD ash and 6 samples of wet FGD gypsum were analyzed. The total 7 samples were extracted using a modification of sequential chemical extractions (SCE) method, which was employed for the partitioning Hg into four fractions: water soluble, acid soluble, H2O2 soluble, and residual. The Hg analysis was done with United States Environmental Protection Agency (USEPA) method 7471B. Comparing with the wet FGD gypsums of coal-fired boilers, the total Hg content in the dry FGD by-product was as high as 1.22 mg/kg, while the total Hg content in the FGD gypsum is 0.23 - 0.74 mg/kg, which was 2 times over the wet FGD gypsum. The concentration of water soluble Hg in the dry FGD by-product was the highest amount (0.72 mg/kg), accounting for 59.02% of the total mercury. While residual Hg content was 0.16 mg/kg, only about 13.11% of the total mercury. Mercury content in FGD gypsum was expressed in the form of ρ (residual Hg) > ρ (H2O2 soluble Hg) > ρ (water soluble Hg) > ρ (acid soluble Hg). The morphology and distribution of mercury in FGD by-products is supposed to be analyzed before utilization, and the impact of mercury on the environment should be considered.