Development of a novel fungal consortium for the treatment of molasses distillery wastewater

In India, cane molasses–based distilleries are major production centers of ethanol. These industries release a dark brown colored effluent known as spent wash, which even after anaerobic treatment retains the color. The commonly used practices of treatment fail to remove the color and COD. A novel fungal consortium was developed for the treatment of this recalcitrant wastewater. The consortium was run on a bioreactor with undiluted distillery effluent for 40 days. In the first 14 days, 61.5% color and 65.4% COD removal was achieved. Further, the fungi were able to use wheat straw as carbon source as evidenced by scanning electron microscopy (SEM) while treating the distillery wastewater. It is expected that such a treatment step will lead to development of a treatment technology for distillery wastewater without the need for diluting it.     

Biomass from phytopathogens and culture conditions improve Penicillium chrysogenum antimicrobial activity and antifungal compounds production

The present study evaluated the effect of culture conditions and phytopathogenic strain co-culture on the production of antimicrobial metabolites and antifungal activity of Penicillium chrysogenum R1, which PCR identified. Antimicrobial activity was determined using the Hunter-Hunter experimental design with three factors (pH, incubation temperature, and inoculum, at two levels each). The antifungal metabolites, β 1-3 glucanase and chitinase, produced in the presence of live and inactivated Fusarium oxysporum Fsox C11 biomass, were evaluated using HPLC-MS and GC-MS. Results showed that P. chrysogenum inhibited the growth of five phytopathogenic fungal strains, and the most significant inhibition was observed for F. oxysporum Fsox C11. The best conditions to achieve the highest antifungal activity of the cell-free extract were pH 7, 28°C, 1 × 10⁶ spores/mL, and 144 h of fermentation, observing 86% inhibition of F. oxysporum Fsox C11 growth. Production of antifungal metabolites such as 1,4-benzoquinone imine, viridicatic acid, phenol-5-methyl-2-(1-methyl ethyl), and hydrolytic enzymes β 1-3 glucanase and chitinase was detected. The results define the perspective in designing new processes and products for biocontrol phytopathogens.     

Changes in Labile Organic Carbon Fractions and Soil Enzyme Activities after Marshland Reclamation and Restoration in the Sanjiang Plain in Northeast China

The extensive reclamation of marshland into cropland has tremendously impacted the ecological environment of the Sanjiang Plain in northeast China. To understand the impacts of marshland reclamation and restoration on soil properties, we investigated the labile organic carbon fractions and the soil enzyme activities in an undisturbed marshland, a cultivated marshland and three marshlands that had been restored for 3, 6 and 12?years. Soil samples collected from the different management systems at a depth of 0-20?cm in July 2009 were analyzed for soil organic carbon (SOC), dissolved organic carbon (DOC), microbial biomass carbon (MBC) and easily degradable organic carbon. In addition, the activities of the invertase, β-glucosidase, urease and acid phosphatase were determined. These enzymes are involved in C, N and P cycling, respectively. Long-term cultivation resulted in decreased SOC, DOC, MBC, microbial quotient and C (invertase, β-glucosidase) and N-transforming (urease) enzyme activities compared with undisturbed marshland. After marshland restoration, the MBC and DOC concentrations and the soil invertase, β-glucosidase and urease activities increased. Soil DOC and MBC concentrations are probably the main factors responsible for the different invertase, β-glucosidase and urease activities. In addition, marshland restoration caused a significant increase in the microbial quotient, which reflects enhanced efficiency of organic substrate use by microbial biomass. Our observations demonstrated that soil quality recovered following marshland restoration. DOC, MBC and invertase, β-glucosidase and urease activities were sensitive for discriminating soil ecosystems under the different types of land use. Thus, these parameters should be considered to be indicators for detecting changes in soil quality and environmental impacts in marshlands.     

Wastewater management in a cane molasses distillery involving bioresource recovery

Waste management involving bioresource recovery in a cane molasses-based distillery engaged in the manufacture of rectified spirit (alcohol) is described. The spentwash generated from the distillation of fermenter wash is highly acidic (pH 4.0-4.3) with high rates of biochemical and chemical oxygen demand (BOD: 52-58, COD: 92-100 kg/m3) and suspended solids (2.0-2.5 kg/m3). Biogas is recovered from high strength raw spentwash through the full-scale application of a biomethanation system as pretreatment option, comprising anaerobic fixed film reactors. This, combined with subsequent concentration through multiple effect evaporators (MEE), and utilization of concentrated effluent for biocomposting of pressmud (another by-product of the industry) for production of biomanure contributes to the elimination of effluent discharges.     

The Effects of Gas Flow Rate and the Interval Time of Water Supplement on Ethanol Production of Rice Straw by Simultaneous Saccharification and Fermentation

In the present work, characteristics of ethanol production from a single particle composing of pretreated rice straw, cellulase, and β-glucosidase were invesitgated by simultaneous saccharification and fermentation (SSF). The experiment experienced a start-up stage for S. cerevisiae biofilm formation, which was operated at an initial pH value of 4.8 for yeast solution, culture temperature of 30°C, flow rate of 0.8 mL/min for yeast solution, and stably operating stage for ethanol production at a culture temperature of 30°C. Investigations found that the maximal ethanol yield of 9.7 mg/g and the biofilm thickness of 0.37 mm were obtained at 30 mL/min of carrier gas flow rate. Also, the optimal interval time of water supplement was 4 h for SSF. The results show that the appropriate gas flow rate and the interval time of water supplement can keep the high activities of biofilm and enzymes during SSF and result in a high ethanol yield.     

Enhancement in biodegradability of distillery wastewater using enzymatic pretreatment

A combined treatment technique consisting of enzymatic hydrolysis, followed by aerobic biological oxidation was investigated for the treatment of alcohol distillery spent wash. The enzyme cellulase was used for the pretreatment step with an intention of transforming the complex and large pollutant molecules into simpler biologically assimilable smaller molecules. Batch experiments were performed in order to analyze the influence of various parameters like pretreatment time, enzyme concentration and pH during the pretreatment step on the subsequent aerobic oxidation kinetics. The rate of aerobic oxidation was enhanced by 2.3 fold for the pretreated sample as compared to the untreated sample when the pH during the pretreatment step was maintained at a value of 4.8. Similarly, a two fold increase in the aerobic oxidation rate was found when the effluent was pretreated with the enzyme, without any pH control (i.e. effluent pH of 3,8). The study indicated that the enzymatic pretreatment of the effluent could be one of the successful pretreatments which can lead to enhancement of the rate of the subsequent aerobic oxidation.     

Effect of amendment of bauxite processing sand with organic materials on its chemical,physical and microbial properties

The effects of addition of a range of organic amendments (biosolids, spent mushroom compost, green waste compost and green waste-derived biochar), at two rates, on some key chemical, physical and microbial properties of bauxite-processing residue sand were studied in a laboratory incubation study. Levels of exchangeable cations were not greatly affected by additions of amendments but extractable P was increased significantly by mushroom and green waste composts and massively (i.e. from 11.8 to 966 mg P kg^?1) by biosolids applications. Levels of extractable NO₃^?–N were also greatly elevated by biosolids additions and there was a concomitant decrease in pH. Addition of all amendments decreased bulk density and increased mesoporosity, available water holding capacity and water retention at field capacity (?10 kPa), with the higher rate having a greater effect. Addition of biosolids, mushroom compost and green waste compost all increased soluble organic C, microbial biomass C, basal respiration and the activities of β-glucosidase, L-asparaginase and alkali phosphatase enzymes. The germination index of watercress grown in the materials was greatly reduced by biosolids application and this was attributed to the combined effects of a high EC and high concentrations of extractable P and NO₃^?. It was concluded that the increases in water storage and retention and microbial activity induced by additions of the composts is likely to improve the properties of bauxite-processing residue sand as a growth medium but that allowing time for soluble salts, originating from the organic amendments, to leach out may be an important consideration before sowing seeds.     

Optimization of Fenton oxidation pre-treatment for B. thuringiensis – Based production of value added products from wastewater sludge

Fenton oxidation pretreatment was investigated for enhancement of biodegradability of wastewater sludge (WWS) which was subsequently used as substrate for the production of value- added products. The Response surface method with fractional factorial and central composite designs was applied to determine the effects of Fenton parameters on solubilization and biodegradability of sludge and the optimization of the Fenton process. Maximum solubilization and biodegradability were obtained as 70% and 74%, respectively at the optimal conditions: 0.01 ml H₂O₂/g SS, 150 [H₂O₂]₀/[Fe²⁺]₀, 25 g/L TS, at 25 °C and 60 min duration. Further, these optimal conditions were tested for the production of a value added product, Bacillus thuringiensis (Bt) which is being used as a biopesticide in the agriculture and forestry sector. It was observed that Bt growth using Fenton oxidized sludge as a substrate was improved with a maximum total cell count of 1.63 × 10⁹ CFU ml^?1 and 96% sporulation after 48 h of fermentation. The results were also tested against ultrasonication treatment and the total cell count was found to be 4.08 × 10⁸ CFU ml^?1 with a sporulation of 90%. Hence, classic Fenton oxidation was demonstrated to be a rather more promising chemical pre-treatment for Bt - based biopesticide production using WWS when compared to ultrasonication as a physical pre-treatment.     

Cost analysis in laccase production

In this paper the cost of producing the enzyme laccase by the white-rot fungus Trametes pubescens under both submerged (SmF) and solid-state fermentation (SSF) conditions was studied. The fungus was cultured using more than 45 culture medium compositions. The cost of production was estimated by analyzing the cost of the culture medium, the cost of equipment and the operating costs. The cost of the culture medium represented, in all cases, the highest contribution to the total cost, while, the cost of equipment was significantly low, representing less than 2% of the total costs. The cultivation under SSF conditions presented a final cost 50-fold lower than the one obtained when culturing under SmF conditions at flask scale. In addition, the laccase production under SSF conditions in tray bioreactors reduced the final cost 4-fold compared to the one obtained under SSF conditions at flask scale, obtaining a final price of 0.04 cent €/U.     

Environmental resource footprinting of drug manufacturing: Effects of scale-up and tablet dosage

The formulation and scale-up of batch processes is one of the major challenges in the development of pharmaceutical dosage forms and at the same time a significant resource demanding process which is generally overlooked in environmental sustainability assessments. First, this paper proposes general trends in the experience curve of cumulative resource consumption of pharmaceutical tablet manufacturing of PREZISTA^® 800 mg through wet granulation (WG) at four consecutive scales in both R&D and manufacturing environments (resp. WG1 = 1 kg/h, WG5 = 5 kg/h, WG30 = 30 kg/h and WG240 = 240 kg/h). Second, the authors aim at evaluating the environmental impact from a life cycle perspective of a daily consumption of PREZISTA^® 2× 400 mg tablets versus the bioequivalent PREZISTA^® 800 mg tablet which was launched to enhance patient compliance. Environmental sustainability assessment was conducted at three different system boundaries, which enables identification, localization and eventually reduction of burdens, in this case natural resource extraction. Exergy Analysis (EA) was used at process level (α) and plant level (β) while a cradle-to-gate Exergetic Life Cycle Assessment (ELCA) was conducted at the overall industrial level (γ) by means of the CEENE method (Cumulative Exergy Extraction from the Natural Environment). Life cycle stages taken into account are Active Pharmaceutical Ingredient (API) production, Drug Product (DP) production and Packaging. At process level (α), the total resource extraction for the manufacturing of one daily dose of PREZISTA^® (800 mg tablet) amounted up to 0.44 MJ_ex at the smallest scale (WG1) while this amount proved to be reduced by 58%, 79% and 83% at WG5, WG30 and WG240 respectively. Expanding the boundaries to the overall industrial level (γ) reveals that the main resource demand is at the production of the Active Pharmaceutical Ingredient (API), excipients, packaging materials and cleaning media used in DP production. At the largest scale (WG240) the use of cleaning media during DP production contributes considerably less to the total resource extraction. Overall, the effect of scale-up and learning on resource consumption during DP production showed to possess a power-law experience curve y = 2.40 * x^−0.57 when shifting from WG1 (smallest lab scale) to WG240 (industrial manufacturing). Tablet dosage (2× 400 mg versus 1× 800 mg) did not significantly affect the absolute environmental burden. However, the relative contribution of resource categories did change due to the different production technology. It could be concluded that in meeting social and economic demands by launching the PREZISTA^® 800 mg tablet, no trade-off in environmental burden occurred. On the long term, future research should strive to take into account R&D processes and all services related to pipeline activities taking place prior to market launch and eventually to allocate impacts to the final product.     

Use of wastewater and compost extracts as nutrient sources for growing nursery and turfgrass species

Nutrient salts present in liquid by-products following waste treatment are lost resources if not effectively recycled, and can cause environmental problems if improperly disposed. This research compared the growth response and mineral nutrient status of two nursery and two turfgrass species, hydroponically supplied with nutritive by-product extracts derived from anaerobically digested municipal solid waste (MSW) and aerobically composted organic wastes from the mushroom and MSW industries. Forsythia (Forsythia x intermedia 'Lynwood') and weigela (Weigela florida 'Red Prince'), and creeping bentgrass (Agrostis palustris Huds.) and Kentucky bluegrass (Poa pratensis L.), were grown in nutrient solutions/extracts prepared from: (i) half-strength Hoagland's #2 solution (HH; control), (ii) Plant Products liquid fertilizer (PP; g kg(-1): 180 N; 39 P; 224 K), (iii) spent mushroom compost (SMC), (iv) MSW compost (GMC), and (v) intra-process wastewater from the anaerobic digestion of MSW (ADW). Additional nutrient solutions (SMC-A, GMC-A, and ADW-A) were prepared by amending the original solutions with N, P, and/or K to concentrations in HH (mg L(-1): 105 N; 15 P; 118 K). Plants receiving the SMC-A extract grew best or at least as well as those in HH, PP, and the amended GMC-A and ADW-A solutions. This study indicated that, with proper amendments of N, P, K and other nutrients, water-soluble constituents derived from organic waste treatment have potential for use as supplemental nutrient sources for plant production.     

Use of spent substrate after Pleurotus pulmonarius cultivation for the treatment of chlorothalonil containing wastewater

Lignocellulosic materials are used as substrate for the cultivation of the edible mushroom Pleurotus pulmonarius. After two or three flushes of mushrooms, the spent substrate is discarded although it still has an important enzymatic activity that can be used for several purposes. In this study, we sought to determine the technical feasibility of using spent substrate from P. pulmonarius to degrade chlorothalonil. Reaction mixture was prepared with 6 ml of pesticide aqueous solution (2 mg active ingredient/l) and 3 ml of enzymatic extract obtained from spent P. pulmonarius substrate. The enzymatic reaction (27 °C, pH 7.4) was conducted for 1 h with sampling at 15 min intervals. The effect of storage time and temperature (freezing or refrigerating) of spent substrate and enzymatic extract, respectively, on the activity over chlorothalonil was determined. Freshly obtained spent substrate extract was able to reduce 100% of the initial concentration of chlorothalonil (2 mg/l) after 45 min of reaction. Storage time had a negative effect on the stability of the enzymatic activity: with spent substrate stored for a week, chlorothalonil concentration was reduced in 49.5% after 1 h reaction and with substrate stored for two and three weeks, the degradation efficiency decreased to 9.15% and 0%, respectively. Cooling and freezing the spent substrate extract also had a negative effect on chlorothalonil degradation.     

Yield and Water Productivity of Winter Wheat under Various Irrigation Capacities

The Agricultural Production Systems sIMulator model validated in a prior study for winter wheat was used to simulate yield, aboveground crop biomass (BM), transpiration (T), and evapotranspiration under four irrigation capacities (ICs) (0, 1.7, 2.5, and 5 mm/day) with two nitrogen (N) application rates (N1, 94 kg N/ha; N2, 160 kg N/ha) to (1) understand the performance of winter wheat under different ICs and (2) develop crop water production function under various ICs and N rates. Evaluation was based on yield, aboveground crop BM, transpiration productivity (TP), crop water productivity (WP), and irrigation WP (IWP). Simulation results showed winter wheat yield increased with increase in N application rate and IC. However, the rate of yield increase gradually reduced with additional irrigation beyond 2.5 mm/day. A 5 mm/day IC required a total of 190 mm irrigation and produced a 5%–16% yield advantage over 2.5 mm/day. This indicates it is possible to reduce groundwater use for wheat by 50% incurring only 5%–16% yield loss relative to 5 mm/day. The TP and IWP for grain were slightly higher under IC of 1.7 mm/day (15.2–16.1 kg/ha/mm and 0.98–1.6 kg/m³) when compared to 5 mm/day (14.7–15.5 kg/ha/mm and 0.6–1.06 kg/m³), respectively. Since TP and IWPs are relatively higher under lower ICs, winter wheat could be a suitable crop under lower ICs in the region. Relationship between yield–T and yield–ET was linear with a slope of 15–16 and 9.5–10 kg/ha/mm, respectively. Editor's note : This paper is part of the featured series on Optimizing Ogallala Aquifer Water Use to Sustain Food Systems. See the February 2019 issue for the introduction and background to the series.     

Upgrading of distillery effluent by Nitrosococcus oceanus for its use as a low-cost fertilizer

Distillery effluent can be converted into biogas and the residue can be utilized as a fertilizer if it is detoxified. Several nitrifying bacteria were screened for detoxification of distillery effluent rich in chloride, nitrogen compounds, free ammonia and monovalent cations. Nitrosococcus oceanus collected from a brackish water lake (Chilka, Orrisa) was noticed to be a potential candidate for detoxification of distillery effluent. The detoxified distillery effluent was used in rice plant culture. The growth and development of rice plants was examined in terms of DCPIP—Hill activity, total carbohydrate, total protein and biomass of rice plants. The detoxified effluent-treated rice plants showed better growth and development as compared with control plant grown in full nutrient solution (Hoagland solution).     

Enhancing the benefits of outdoor walking with cognitive engagement strategies

Being physically active in natural environments has been associated with improvements to physical health and mental well-being. Unfortunately, gaining access to outdoor settings that are supportive of both psychological well-being and year-round physical activity poses major challenges. Might altering how one engages in and interacts with the outdoor environment encouraging greater physical activity and enhance well-being? In order to investigate this approach, 117 adults were randomly assigned to one of two treatments - Standard Care (schedule setting, commitment) or Engagement (awareness plans) - and asked to take at least three, 30 minutes outdoor walks each week for two weeks. Participants in both treatment conditions reported significant increases in total time spent walking (p ≤ .05). Only those in the Engagement condition, however, experienced significant improvements in multiple dimensions of psychological well-being, including attentional functioning and feelings of frustration. In addition, participants in the engagement-based condition who walked at low to moderate levels were more likely to obtain psychological benefits. The results of this study suggest that promoting cognitive engagement with the environment may make it easier for individuals to achieve the psychological benefits typically associated with outdoor physical activity, even in settings that are less than ideal.     

Evaluation of biogas production from seaweed in batch tests and in UASB reactors combined with the removal of heavy metals

Seaweed can be anaerobically digested for the production of energy-rich methane. However, the use of seaweed digestate as a fertilizer may be restricted because of the high heavy metal content especially cadmium. Reducing the concentration of heavy metals in the digestate will enable its use as a fertilizer. In this laboratory-scale study, the potential of seaweed and its leachate in the production of methane were evaluated in batch tests. The effect of removing the heavy metals from seaweed leachate was evaluated in both batch test and treatment in an upflow anaerobic sludge blanket (UASB) reactor. The heavy metals were removed from seaweed leachate using an imminodiacetic acid (IDA) polyacrylamide cryogel carrier. The methane yield obtained in the anaerobic digestion of seaweed was 0.12 N l CH₄/g VS_added. The same methane yield was obtained when the seaweed leachate was used for methane production. The IDA-cryogel carrier was efficient in removing Cd²⁺, Cu²⁺, Ni²⁺ and Zn²⁺ ions from seaweed leachate. The removal of heavy metals in the seaweed leachate led to a decrease in the methane yield. The maximum sustainable organic loading rate (OLR) attained in the UASB reactor was 20.6 g tCOD/l/day corresponding to a hydraulic retention time (HRT) of 12 h and with a total COD removal efficiency of about 81%. Hydrolysis and treatment with IDA cryogel reduced the heavy metals content in the seaweed leachate before methane production. This study also demonstrated the suitability of the treatment of seaweed leachate in a UASB reactor.     

Interaction effects of organic load and cycle time in an AsBr applied to a personal care industry wastewater treatment

A mechanically stirred anaerobic sequencing batch reactor (ASBR) containing granular biomass was applied to the treatment of a wastewater simulating the effluent from a personal care industry. The ASBR was operated with cycle lengths (t_C) of 8, 12 and 24 h and applied volumetric organic loads (AVOL) of 0.75, 0.50 and 0.25 gCOD/L.d, treating 2.0 L liquid medium per cycle. Stirring frequency was 150 rpm and the reactor was kept in an isothermal chamber at 30 °C. Increase in t_C resulted in efficiency increase at constant AVOL, reaching 77% at t_C of 24 h versus 69% at t_C of 8 h. However, efficiency decreased when AVOL decreased as a function of increasing t_C, due to the lack of substrate in the reaction medium. Moreover, replacing part of the wastewater by a chemically balanced synthetic one did not yield the expected effect and system efficiency dropped.     

Polyurethane rotating disc system for post-treatment of anaerobically pre-treated sewage

The performance of polyurethane rotating discs (RBC-1) versus polystyrene rotating discs (RBC-2) for the treatment of an up-flow anaerobic sludge blanket (UASB) reactor effluent fed with domestic wastewater was investigated. Both RBC units were operated at the same organic loading rate (OLR) of 10.5 gCOD/m² d. and a hydraulic retention time (HRT) of 2.5 h. The residual values of COD fractions (COD_suspended, COD_colloidal and COD_soluble) in the treated effluent of RBC-1 and RBC-2 were similar. However, the removal efficiency of ammonia in the RBC-1 (87 ± 4%) was significantly higher than that found for RBC-2 i.e. 24 ± 6%. Moreover, RBC-1 achieved a substantial removal efficiency of 99.0 ± 1% for Escherichia coli (E. coli), while RBC-2 removed 91.2 ± 0.3%. Based on these results, optimization of RBC-1 treating UASB reactor effluent was extensively performed. The RBC-1 was operated at an OLR's of 4.0, 11 and 23 gCOD/m² d. The results obtained showed that increasing the OLR from 11.0 to 23.0 gCOD/m² d and decreasing the HRT from 2.5 to 1.25 h significantly declined the effluent quality of COD_total and ammonia. However, the residual values of COD_total and ammonia remained unaffected when increasing the OLR from 4.0 to 11.0 gCOD/m² d and by decreasing the HRT from 5 to 2.5 h. Bacteriological examination showed that the mean residual count of E. coli remained at a level of 10⁴/100 ml, in the effluent of RBC-1 independent on the imposed HRT. Accordingly, it is recommended to operate RBC-1 for treatment of anaerobically pre-treated sewage at an OLR of 11 gCOD/m² d and an HRT of 2.5 h.A feed-less (ammonia limitation) period of 9.0 days followed by 9.0 days feeding with high OLR of 26 gCOD/m² d. (raw sewage) was investigated to elaborate, if the nitrifiers of the RBC-1 are capable to convert ammonia to nitrate after totally 18 days when retuning back to the normal operating conditions. The results of the experiment clearly show a strong and immediate detrimental effect of imposing high OLR of 26 gCOD/m² d on the nitrification process in the nitrifying RBC unit. However, after returning back to the original OLR of 10.6 gCOD/m² d, the nitrification efficiency in the RBC unit was recovered within 2–3 days.     

A comparison of pretreatments on release of sugars from sweet sorghum bagasse for bioethanol production

Dilute acid pretreatment and steam pretreatment were evaluated for maximum sugars release and ethanol production from sweet sorghum bagasse (SSB). The fermentation potential of the condensate and hydrolysate obtained from steam pretreatment (10 kg/cm², 10 minutes) and dilute acid hydrolysis (1% (w/w) sulphuric acid, 25% substrate loading) respectively, was checked with Pichia stipitis NCIM 3497 and Debaryomyces hansenii sp. Ethanol production and yield using acid hydrolysate was higher with Debaryomyces hansenii sp. (28.4 g/L and 0.37 g/g respectively) as compared with Pichia stipitis NCIM 3497 (21.9 g/L and 0.29 g/g respectively).     

Odorants and malodors associated with land application of biosolids stabilized with lime and coal fly ash

Malodor emissions limit public acceptance of using municipal biosolids as natural organic resources in agricultural production. We aimed to identify major odorants and to evaluate odor concentrations associated with land application of anaerobically digested sewage sludges (Class B) and their alkaline (lime and coal fly ash)-stabilized products (Class A). These two types of biosolids were applied at 12.6 tonnes ha(-1) (dry weight) to microplots of very fine clayey Vertisol in the Jezreel Valley, northern Israel. The volatile organic compounds (VOCs) emitted from the biosolids before and during alkaline stabilization and after incorporation into the soil were analyzed by headspace solid-phase microextraction followed by gas chromatography-mass spectrometry. Odor concentrations at the plots were evaluated on site with a Nasal Ranger field olfactometer that sniffed over a defined land surface area through a static chamber. The odors emitted by anaerobically digested sewage sludges from three activated sludge water treatment plants had one characteristic chemical fingerprint. Alkaline stabilization emitted substantial odors associated with high concentrations of ammonia and release of nitrogen-containing VOCs and did not effectively reduce the potential odor annoyance. Odorous VOCs could be generated within the soil after biosolids incorporation, presumably because of anaerobic conditions within soil-biosolids aggregates. We propose that dimethyl disulfide and dimethyl trisulfide, which seem to be most related to the odor concentrations of biosolids-treated soil, be used as potential chemical markers for the odor annoyance associated with incorporation of anaerobically digested sewage sludges.