Environ Sci Pollut Res DOI 10.1007/s11356-015-5251-7
RESEARCH ARTICLE
Effects of poultry manure on soil biochemical properties in phthalic acid esters contaminated soil Jun Gao 1,2 & Xiaojian Qin 1,2 & Xuqin Ren 2 & Haifeng Zhou 3
Received: 8 June 2015 / Accepted: 13 August 2015 # Springer-Verlag Berlin Heidelberg 2015
Abstract This study aimed to evaluate the effects of poultry manure (PM) on soil biological properties in DBP- and DEHP-contaminated soils. An indoor incubation experiment was conducted. Soil microbial biomass C (Cmic), soil enzymatic activities, and microbial phospholipid fatty acid (PLFA) concentrations were measured during incubation period. The results indicated that except alkaline phosphatase activity, DBP and DEHP had negative effects on Cmic, dehydrogenase, urease, protease activities, and contents of total PLFA. However, 5 % PM treatment alleviated the negative effects of PAEs on the above biochemical parameters. In DBPcontaminated soil, 5 % PM amendment even resulted in dehydroenase activity and Cmic content increasing by 17.8 and 11.8 % on the day 15 of incubation, respectively. During the incubation periods, the total PLFA contents decreased maximumly by 17.2 and 11.6 % in DBP- and DEHP-contaminated soils without PM amendments, respectively. Compared with those in uncontaminated soil, the total PLFA contents increased slightly and the value of bacPLFA/ fugalPLFA increased significantly in PAE-contaminated soils with 5 % PM amendment. Nevertheless, in both contaminated soils, the effects of 5 % PM amendment on the biochemical parameters were not observed with 10 % PM amendment. In Responsible editor: Zhihong Xu * Jun Gao [email protected] 1
Life Science and Food Engineering School, Huaiyin Institute of Technology, Huai’an 223003, China
2
Key Laboratory for Palygorskite Science and Applied Technology of Jiangsu Province, Huaian 223003, China
3
Huaian Wanbang Aromatic Chemicals Industry Co., Ltd., Huai’an, Jiangsu 223300, China
10 % PM-amended soils, DBP and DEHP had little effect on Cmic, soil enzymatic activities, and microbial community composition. At the end of incubation, the effects of PAEs on these parameters disappeared, irrespective of PM amendment. The application of PM ameliorated the negative effect of PAEs on soil biological environment. However, further work is needed to study the effect of PM on soil microbial gene expression in order to explain the change mechanisms of soil biological properties. Keywords Phthalate acid esters . Microbial biomass C . Soil enzymatic activity . Phospholipid fatty acid . Poultry manure
Introduction Phthalate acid esters (PAEs) are extensively used in the plastics industry as adhesives and plasticizers for polyvinyl chloride (PVC) materials to improve flexibility and processability. And, they are also used as nonplasticizers in consumer products such as lubricating oils, automobile parts, paints, glues, insect repellents, photographic films, perfumes, and food packaging (Staples et al. 1997). Accordingly, the global production of PAEs is approximately 6.0 million tons per year (Zeng et al. 2009). Because of their chemical properties, high production volumes, and widespread applications, PAEs have been ubiquitous in air, soil, water, sediment, and other environmental compartments (Fauser and Thomsen 2002; Suzuki et al. 2001). The sewage irrigation and the excessive application of agricultural chemicals (e.g., pesticides and plastic film) were also contributed to elevated levels for PAEs in cultured soils (Mo et al. 2008). Hu et al. (2003) founded the values of PAEs in soils collected from different regions of China were considerably higher than those reported in soils form the Netherlands (Peijnenburg and Struijs 2006). Cai et al. (2005)
Environ Sci Pollut Res
also founded the value of six PAEs (ΣPAEs) ranged from 0.89 to 46 mg kg−1, with a mean value of 5.5±6.8 mg kg−1, in vegetable soils within the Pearl River Delta. Among all PAEs, platicizers di-n-butyl phthalate (DBP) and di-(2-ethyl hexyl) phthalate (DEHP) are the dominant components in environment. Accumulation of PAEs in the agricultural soils may lead to contamination of vegetables and food chains, which contributes to direct or indirect human exposure (Mo et al. 2008). The performed investigations have shown that several PAEs are carcinogenic and environmental hormones (Kambia et al. 2001; Huber et al. 1996). So, the Environmental Protection Agency (EPA) of the USA has listed six PAEs as environmental priority pollutants. So have the China State Environmental Protection Administration (SEPA) and the European Community. The analysis on soil microbial biomass, microbial community composition, and soil enzymatic activity is often used to characterize the changes and dynamics of soil quality and health because these indicators are sensitive to the ecological stress and can provide information about pollutants effects on soil health (García-Orenes et al. 2010; Andreoni et al. 2004). Among them, the phospholipid fatty acid (PLFA) assay often is used to characterize the changes in microbial community composition (Baker et al. 2011). Several studies demonstrated that the present of DEHP in soil altered the microbial properties and enzymatic activities (Wang et al. 2009; Qin et al. 2005). The addition of organic matter to contaminated soil may play an important role in reducing the negative effects of contaminants on soil microbial communities, enzyme activities, and other soil biological properties. In this respect, the effects of different organic matters (straw, poultry manure, sewage sludge, etc.) on soil biological properties were reported in PAH-contaminated soils (Tejada and Masciandaro 2011; Sayara et al. 2011; Tejada et al. 2011). Besides the immobilization of contaminants, these organic matters contributed nutrients to soil microbes and accelerated contaminant biodegradation (Tejada et al. 2011; Maria-Carmen et al. 2014). However, the effects of organic matter on soil biochemical properties may depend on the amount, type, and dominant component of organic mater as well as the structure and property of contaminant in soil. In PAE-contaminated soil, the application of organic matters has been proved to improve DBP and DEHP degradation (Chang et al. 2009; Yuan et al. 2010). But, little information is available about the effects of organic matter on soil microbial biomass, microbial community composition, and soil enzyme activity in PAE-contaminated soil. In order to understand the effects of PM on the biological toxicities of PAEs in soil, microbial biomass C, soil dehydrogenase, urease, protease and phosphatase activities, and soil PLFA profile were measured through a series of batch experiments in PAEcontaminated soil with PM amendment. DBP and DEHP were
selected as the representatives of PAEs, and respectively mixed with soil to form artificially contaminated soil.
Materials and methods Soil, organic amendment, and PAEs DBP and DEHP, both of 99.0 % analytical standard grades, were obtained from Chem Service (West Chester, PA, USA). The soil used in this experiment is clay loam. Soil collected from the surface layer (0–20 cm) was air-dried and sieved to 2 mm. The main soil characteristics are shown in Table 1. Poultry manure was collected from a local poultry farm and composted on July 8, 2012, in open air. It was covered with plastic film during its composting period, maintained moisture contents at around 50 %, and turned every 7 days in order to improve O2 level inside the pile. The composting process lasted 4 weeks. Composting was considered completed when C/N ratio and temperature became constant. Then, it was air dried, crushed, and sieved through a 2-mm mesh screen. The main characteristics are also shown in Table 1. Incubation procedure Soil samples were artificially contaminated by DBP or DEHP at 100 mg kg−1 soil, respectively (dissolved in acetone), and mixed with PM at rates of 5 and 10 %, respectively. Nonamended treatments and/or uncontaminated treatments were used as controls. The incubation treatments are detailed in Table 2. All the above soil samples were at 60 % of their waterholding capacity during incubation. Triplicate treatments were kept in semi-closed glass beakers in the dark at 28±1 °C for 1, 7, 15, 30, and 60 days, respectively. For each treatment and each incubation time, about 200 g of soil was taken for analysis. Table 1 Characteristics of the soil and compost employed in the experiment Parameters
Soil
PM
pH (soil/H2O=1:2.5) Sand (2000–50 μm) (%) Silt (
RESEARCH ARTICLE
Effects of poultry manure on soil biochemical properties in phthalic acid esters contaminated soil Jun Gao 1,2 & Xiaojian Qin 1,2 & Xuqin Ren 2 & Haifeng Zhou 3
Received: 8 June 2015 / Accepted: 13 August 2015 # Springer-Verlag Berlin Heidelberg 2015
Abstract This study aimed to evaluate the effects of poultry manure (PM) on soil biological properties in DBP- and DEHP-contaminated soils. An indoor incubation experiment was conducted. Soil microbial biomass C (Cmic), soil enzymatic activities, and microbial phospholipid fatty acid (PLFA) concentrations were measured during incubation period. The results indicated that except alkaline phosphatase activity, DBP and DEHP had negative effects on Cmic, dehydrogenase, urease, protease activities, and contents of total PLFA. However, 5 % PM treatment alleviated the negative effects of PAEs on the above biochemical parameters. In DBPcontaminated soil, 5 % PM amendment even resulted in dehydroenase activity and Cmic content increasing by 17.8 and 11.8 % on the day 15 of incubation, respectively. During the incubation periods, the total PLFA contents decreased maximumly by 17.2 and 11.6 % in DBP- and DEHP-contaminated soils without PM amendments, respectively. Compared with those in uncontaminated soil, the total PLFA contents increased slightly and the value of bacPLFA/ fugalPLFA increased significantly in PAE-contaminated soils with 5 % PM amendment. Nevertheless, in both contaminated soils, the effects of 5 % PM amendment on the biochemical parameters were not observed with 10 % PM amendment. In Responsible editor: Zhihong Xu * Jun Gao [email protected] 1
Life Science and Food Engineering School, Huaiyin Institute of Technology, Huai’an 223003, China
2
Key Laboratory for Palygorskite Science and Applied Technology of Jiangsu Province, Huaian 223003, China
3
Huaian Wanbang Aromatic Chemicals Industry Co., Ltd., Huai’an, Jiangsu 223300, China
10 % PM-amended soils, DBP and DEHP had little effect on Cmic, soil enzymatic activities, and microbial community composition. At the end of incubation, the effects of PAEs on these parameters disappeared, irrespective of PM amendment. The application of PM ameliorated the negative effect of PAEs on soil biological environment. However, further work is needed to study the effect of PM on soil microbial gene expression in order to explain the change mechanisms of soil biological properties. Keywords Phthalate acid esters . Microbial biomass C . Soil enzymatic activity . Phospholipid fatty acid . Poultry manure
Introduction Phthalate acid esters (PAEs) are extensively used in the plastics industry as adhesives and plasticizers for polyvinyl chloride (PVC) materials to improve flexibility and processability. And, they are also used as nonplasticizers in consumer products such as lubricating oils, automobile parts, paints, glues, insect repellents, photographic films, perfumes, and food packaging (Staples et al. 1997). Accordingly, the global production of PAEs is approximately 6.0 million tons per year (Zeng et al. 2009). Because of their chemical properties, high production volumes, and widespread applications, PAEs have been ubiquitous in air, soil, water, sediment, and other environmental compartments (Fauser and Thomsen 2002; Suzuki et al. 2001). The sewage irrigation and the excessive application of agricultural chemicals (e.g., pesticides and plastic film) were also contributed to elevated levels for PAEs in cultured soils (Mo et al. 2008). Hu et al. (2003) founded the values of PAEs in soils collected from different regions of China were considerably higher than those reported in soils form the Netherlands (Peijnenburg and Struijs 2006). Cai et al. (2005)
Environ Sci Pollut Res
also founded the value of six PAEs (ΣPAEs) ranged from 0.89 to 46 mg kg−1, with a mean value of 5.5±6.8 mg kg−1, in vegetable soils within the Pearl River Delta. Among all PAEs, platicizers di-n-butyl phthalate (DBP) and di-(2-ethyl hexyl) phthalate (DEHP) are the dominant components in environment. Accumulation of PAEs in the agricultural soils may lead to contamination of vegetables and food chains, which contributes to direct or indirect human exposure (Mo et al. 2008). The performed investigations have shown that several PAEs are carcinogenic and environmental hormones (Kambia et al. 2001; Huber et al. 1996). So, the Environmental Protection Agency (EPA) of the USA has listed six PAEs as environmental priority pollutants. So have the China State Environmental Protection Administration (SEPA) and the European Community. The analysis on soil microbial biomass, microbial community composition, and soil enzymatic activity is often used to characterize the changes and dynamics of soil quality and health because these indicators are sensitive to the ecological stress and can provide information about pollutants effects on soil health (García-Orenes et al. 2010; Andreoni et al. 2004). Among them, the phospholipid fatty acid (PLFA) assay often is used to characterize the changes in microbial community composition (Baker et al. 2011). Several studies demonstrated that the present of DEHP in soil altered the microbial properties and enzymatic activities (Wang et al. 2009; Qin et al. 2005). The addition of organic matter to contaminated soil may play an important role in reducing the negative effects of contaminants on soil microbial communities, enzyme activities, and other soil biological properties. In this respect, the effects of different organic matters (straw, poultry manure, sewage sludge, etc.) on soil biological properties were reported in PAH-contaminated soils (Tejada and Masciandaro 2011; Sayara et al. 2011; Tejada et al. 2011). Besides the immobilization of contaminants, these organic matters contributed nutrients to soil microbes and accelerated contaminant biodegradation (Tejada et al. 2011; Maria-Carmen et al. 2014). However, the effects of organic matter on soil biochemical properties may depend on the amount, type, and dominant component of organic mater as well as the structure and property of contaminant in soil. In PAE-contaminated soil, the application of organic matters has been proved to improve DBP and DEHP degradation (Chang et al. 2009; Yuan et al. 2010). But, little information is available about the effects of organic matter on soil microbial biomass, microbial community composition, and soil enzyme activity in PAE-contaminated soil. In order to understand the effects of PM on the biological toxicities of PAEs in soil, microbial biomass C, soil dehydrogenase, urease, protease and phosphatase activities, and soil PLFA profile were measured through a series of batch experiments in PAEcontaminated soil with PM amendment. DBP and DEHP were
selected as the representatives of PAEs, and respectively mixed with soil to form artificially contaminated soil.
Materials and methods Soil, organic amendment, and PAEs DBP and DEHP, both of 99.0 % analytical standard grades, were obtained from Chem Service (West Chester, PA, USA). The soil used in this experiment is clay loam. Soil collected from the surface layer (0–20 cm) was air-dried and sieved to 2 mm. The main soil characteristics are shown in Table 1. Poultry manure was collected from a local poultry farm and composted on July 8, 2012, in open air. It was covered with plastic film during its composting period, maintained moisture contents at around 50 %, and turned every 7 days in order to improve O2 level inside the pile. The composting process lasted 4 weeks. Composting was considered completed when C/N ratio and temperature became constant. Then, it was air dried, crushed, and sieved through a 2-mm mesh screen. The main characteristics are also shown in Table 1. Incubation procedure Soil samples were artificially contaminated by DBP or DEHP at 100 mg kg−1 soil, respectively (dissolved in acetone), and mixed with PM at rates of 5 and 10 %, respectively. Nonamended treatments and/or uncontaminated treatments were used as controls. The incubation treatments are detailed in Table 2. All the above soil samples were at 60 % of their waterholding capacity during incubation. Triplicate treatments were kept in semi-closed glass beakers in the dark at 28±1 °C for 1, 7, 15, 30, and 60 days, respectively. For each treatment and each incubation time, about 200 g of soil was taken for analysis. Table 1 Characteristics of the soil and compost employed in the experiment Parameters
Soil
PM
pH (soil/H2O=1:2.5) Sand (2000–50 μm) (%) Silt (
