Waste Soil Research Articles

Phytoremediation potential of some agricultural plants on heavy metal contaminated mine waste soils, salem district, tamilnadu

ABSTRACTThe Pot culture experiment performed for phytoextraction potential of selected agricultural plants [millet (Eleusine coracana), mustard (Brassica juncea), jowar (Sorghum bicolor), black gram (Vigna mungo), pumpkin (Telfairia occidentalis)] grown in metal contaminated soils around the Salem region, Tamilnadu, India. Physiochemical characterization of soils, reported as low to medium level of N, P, K was found in test soils. The Cr content higher in mine soils than control and the values are 0.176 mg/L in Dalmia soil and 0.049 mg/L in Burn & Co soil. The germination rate low in mine soil than control soils (25 to 85%). The content of chlorophyll, carotenoid, carbohydrate and protein decreased in mine soils than control. The morphological parameters and biomass values decreased in experimental plants due to metal accumulation. Proline content increased in test plants and ranged from 0.113 mg g−1 to 0.858 mg g−1 which indicate the stress condition due to toxicity of metals. Sorghum and black gram plants reported as metal tolerant capacity. Among the plants, Sorghum produced good results (both biomass and biochemical parameters) which equal to control plant and suggests Sorghum plant is an ideal for remediation of metal contaminated soils.

Settlement Prediction of Soil at Closed Dumping area using Power Creep Function

In Malaysia, total dumping sites are 73 sites, controlled dumping sites are 71 sites and sanitary landfill are 11 sites. These disposal sites will increase over time because population in Malaysia has been increased at a rate of 2.4% per annum or about 600,000 per annum since 1994. The increase in population would increase the amount of waste generated. Thus, it will increase the number of dumping sites. The dumping area which has a full capacity of waste will eventually closed. These closed dumping area which are to be developed for new development are prone to settlement. The settlement at dumping area are to be predicted and simulated using Power Creep Function. The heterogeneous content of waste soil from dumping area are complicated to characterize and classified. The content of waste dumped at the dumping area is important to analyse because the degradation process changes with time. The degradation process are called power creep function. Power Creep Function (PCF) is time dependent deformation which is under constant stress. The two constant variables which are M’ and N’. M’ is the compressibility constant and N’ is rate of compression varies with age placement condition. The input parameters for PCF are H0, ∆σ, t, Tr, M’ and N’. These parameters are simulated based on two cases whereby, case 1 where M’ and N’ are kept constant and time (t) increases from 25 days to 75 days. Tr is kept constant at 1 day. Case 2 is where M’, N’ and Tr are kept constant and time (t) increases from 240 days to 730 days. The settlement prediction at the dumping area for Case 1 is 0.024 meters to 0.042 meters and for Case 2 the settlement is in the range of 0.074 meters to 0.130 meters. The prediction of total settlement for dumping area would be used to determine the depth of foundation for the new development at the dumping area.

Elevating concentrations of capsaicin and dihydrocapsaicin in hot peppers using recycled waste

Five Capsicum accessions (PI 435916 and PI 438614 from Capsicum chinense; PI 370004 and Grif 9354 from C. baccatum and PI 438649 from C. annuum) were selected from the U.S. Department of Agriculture-Agricultural Research Service Capsicum germplasm collection to study the impact of four soil management practices: yard waste (YW), sewage sludge (SS), chicken manure (CM) and no-mulch (NM) bare soil on fruit concentrations of capsaicin and dihydrocapsaicin, yield, plant size and mature fruit characteristics (fruit weight, length, width, and wall-thickness) of plants grown under these practices. Regardless of soil treatments, PI 438614 and PI 435916 contained the greatest concentrations of total capsaicinoids (capsaicin and dihydrocapsaicin). Fruits of plants grown in soil mixed with SS contained the greatest concentrations of total capsaicinoids. Fruits of plants grown in SS or CM contained the greatest fruit weight. PI 438649 produced the greatest fruit weight, length and wall-thickness. The total marketable yield expressed as weight of fruit plants was significantly higher in soils mixed with SS and CM compared to those mixed with YW and NM soils.

English

This paper examined the influence of Lokpa cattle market waste on soil properties. Soil samples were collected from the Central, 3 and 6 m Northwards, Southwards, Eastwards and Westwards of Lokpa cattle market, Umuneochi Local Government Area of Abia State, Nigeria at a depth of 0 to 25 cm (Sample A) and 26 to 50 cm (Sample B) from each spot while the control samples were collected from an unimpacted area devoid of cattle rearing activities. Results of the physicochemical activities show that cattle waste soil had low acid pH range of 4.02 to 5.83 while soil moisture ranged from 14.90 to 21.58, Organic carbon ranged from 1.92 to 2.83. The enzymatic activities of cattle waste soil were found to be higher (P<0.05) than the control. This however could be due to input from the cattle waste leading to increased enzymatic activities. The pH of the cattle waste soils were found to be lower than the control, hence proper care should be taken in the quantity of these waste applied to farms as they can increase soil acidity. The presence of cattle dung could be responsible for the general changes observed. Key words: Cattle, waste, market, soil, quality.

Potential of Using Cemented Soil-Tire Chips Mixture as Construction Fill: a Laboratory Study

ABSTRACT Xin, L.; He, J.; Liu, H., and Shen, Y., 2015. Potential of using cemented soil-tire chips mixture as construction fill: A laboratory study. Waste materials that are generated in large quantities, such as waste rubbers, plastics, and dredged soils, can potentially be reused as fill materials in construction projects. It will bring both economical and environmental benefits. This paper firstly presents a review on different methods of reusing scrap tires and waste soils in constructions. Then, a new method of using these two wastes as a fill material is proposed and experimentally evaluated. The material is formed by mixing waste soils, scrap tire chips, Portland cement, and water together in varying proportions. Isotropic compression and triaxial consolidated undrained compression tests were carried out. The geotechnical properties of the material with varying additions of different components are investigated. It is found that adding more tire chips in the material leads to an evident improvement...

Risk Assessment of Some Selected Vegetables Grown in Metal Contaminated Soil Supplements

Application of municipal solid waste and sewage sludge to supplement soil is an age-old agronomic practice due to its rich organic contents. These soil-supplements also contain significant amount of non-essential heavy metals, posing threat to crop yield and human health. The present study aims to compare the phytotoxicity of the heavy metals and potential dietary toxicity of some selected vegetables grown in soil supplemented with municipal solid waste and sewage sludge. To assess the phytotoxicity of the supplements, plants were grown in three different sets; (1) Hoagland’s nutrient media [as control] (2) municipal solid waste and (3) sewage sludge soil mix. To study the phytotoxic markers, photosynthetic pigments, proline, protein content and antioxidant enzyme activities were measured and metal content of the vegetables were measured to estimate the potential dietary toxicity. It was observed from the study that vegetables grown in supplemented soils showed reduced chlorophyll and protein content while carotenoid, proline and antioxidative enzymes showed enhanced activity. In both the supplemented soil, it was observed that cadmium was present above the maximum allowable limits, amount of lead was marginal and that of chromium was below the level. It was observed that the two leafy vegetables, i.e., Lagenaria sp. and Cucurbita sp. accumulated more lead in their aerial parts, Lagenaria grown in sewage sludge supplemented soil also accumulated significant amount of cadmium in the aerial parts. Edible parts of Raphanus and maize grains also accumulated considerable amount of cadmium, which were above the value of daily tolerable limits.

Evaluation of air-foam stabilized soil of dredged soil waste as a pavement subgrade layer

Air-foam stabilized soil is a kind of waste soil treated with cement and air-foam to make it durable and slight. It has been used widely in geotechnical applications; however, applying in subgrade layer of pavement has not considered. The purposes of this study are the followings: a) the strength properties based on the stress-strain behaviors, b) the durability by simulating the Freeze-Thaw Cycle (FTC), c) thermal conductivity test, and d) the evaluation of pavement performance when the air-foam stabilized soil was used as the subgrade layer. From the results of experiments, it is observed that the strength of air-foam stabilized soil increased with an increase in cement content, but decreased with increasing air-foam content or number of FTCs. The thermal conductivity of air-foam stabilized soil decreased with increasing air-foam content. The resilient modulus of air-foam stabilized soil was determined from the repeated load triaxial test to predict the fatigue and rutting life of the pavement according to AASHTO T 307. The testing results were compared with specification of the Korean pavement design life, and it showed that air-foam stabilized soil is suitable to be used as subgrade material to enhance its properties, and reduce damages such as fatigue cracking and rutting.

Structural and vibrational behaviour of pyromorphite-vanadinite solid solution series

Pyromorphite Pb 5 (PO 4 ) 3 Cl and vanadinite Pb 5 (VO 4 ) 3 Cl belong to the apatite supergroup. They are secondary minerals formed in the oxidation zones of lead ore deposits. Both crystallize in hexagonal symmetry with the space group P6 3 /m (Dong et al. 2002). The crystal structure of these two minerals allows to accommodate both metal cations and anionic complexes. It is the reason, why pyromorphite and vanadinite forms solid solution series. Isovalent replacement of P with V is one of the most common anionic substitution. Lead apatites are one of the least soluble along apatites group minerals and characterized by high thermal stability (Dong et al. 2002, Flis et al. 2011). Characteristic properties of apatite structure cause that these minerals are successfully used in many fields, especially for the immobilization of toxic waste and lead-contaminated soil (Ma et al. 1993, Chen et al. 1997, Dong et al. 2002, Kim et al. 2005). So far, pyromorphite and mimetite are the most known and used for the immobilization of lead. Pyromorphite and mimetite are isostructural with vanadinite, therefore it has been predicted that this mineral is also important for the environment. Accordingly, the aim of this study was to characterize of the pyromorphite-vanadinite solid solution series. This research present systematic changes in the structure of these minerals. Pure pyromorphite and vanadinite and minerals with intermediate compositions Pb 5 (TO 4 ) 3 Cl, where T = P + V, of various P/V ratios were synthesized from aqueous solutions at 298 K and pH = 3.5. Synthetic solids were analyzed by X-Ray diffraction (XRD), infrared absorption spectroscopy (FTIR) and Raman spectroscopy. Based on the X-Ray analysis, it was found that synthetic precipitates represent homogeneous phases of pyromorphite and vanadinite, which have intermediate chemical composition. Diffraction peaks of pyromorphite-vanadinite solid solution series were shifted due to replacement of PO 4 by VO 4 . Replacement of PO 4 by VO 4 anions is causing changes in the structure of apatite and hence these shifts. Unit cell parameters of studied solid solutions show a linear variation. In the FTIR and Raman spectra of pyromorphite-vanadinite solid solutions series, the bands which are characteristic for vibrations of P-O bonds of the PO 4 tetrahedra as well as vibrations of V-O bonds of the VO 4 tetrahedra appeared. Analysis of Mid-IR spectra and Raman spectra also allowed to observe correlation between the band positions and the extent of the anionic substitution among the studied series. The structure of pyromorphite and vanadinite is generally similar, although they vary in chemical composition. Causes of variability are probably connected with the properties of individual ions. The project was financed with resources of the National Science Centre, Poland, granted based on decision no. DEC-2013/09/N/ST10/00677.

震災がれきおよび津波堆積物由来の木屑混じり発生土の有効利用のための土質力学特性と社会的コストの評価

2011年東日本大震災では，震災廃棄物混入土砂や津波堆積土砂が大量に発生した。新たな環境負荷を生まないためにも，これらの発生土砂を建設用地盤材料として有効利用することは，復旧復興のために重要である。しかし，これらの発生土砂には木屑等の有機物が大量に含まれており，地盤材料（例えば建設用盛土材料）として利用するためには，その土質力学特性の評価を行い，適切な用途・箇所に用いる必要がある。また，場合によっては土砂の改質が必要となる。本論文では，大量の木屑が含まれる震災廃棄物混入土砂および津波堆積土砂に，現場と同等の分別方法を用いて粒度分布や有機物含有量が異なる土砂を作成した後，それぞれの土砂に対して盛土材料としての使用可能性を吟味するための土質試験を行った。その結果，適切な対処をすれば，建設地盤材料として実際に利活用できることを示した。また，再生資材を使用する際のコストを検討し，再生資材を利活用することによって社会的コストを減少させることができることを示した。

Impact of soil management practices on yield, fruit quality, and antioxidant contents of pepper at four stages of fruit development

Peppers, a significant component of the human diet in many regions of the world, provide vitamins A (β-carotene) and C, and are also a source of many other antioxidants such as capsaicin, dihydrocapsaicin, and phenols. Enhancing the concentration of antioxidants in plants grown in soil amended with recycled waste has not been completely investigated. Changes in pepper antioxidant content in relation to soil amendments and fruit development were investigated. The main objectives of this investigation were to: (i) quantify concentrations of capsaicin, dihydrocapsaicin, β-carotene, ascorbic acid, phenols, and soluble sugars in the fruits of Capsicum annuum L. (cv. Xcatic) grown under four soil management practices: yard waste (YW), sewage sludge (SS), chicken manure (CM), and no-much (NM) bare soil and (ii) monitor antioxidant concentrations in fruits of plants grown under these practices and during fruit ripening from green into red mature fruits. Total marketable pepper yield was increased by 34% and 15% in SS and CM treatments, respectively, compared to NM bare soil; whereas, the number of culls (fruits that fail to meet the requirements of foregoing grades) was lower in YW compared to SS and CM treatments. Regardless of fruit color, pepper fruits from YW amended soil contained the greatest concentrations of capsaicin and dihydrocapsaicin. When different colored pepper fruits (green, yellow, orange, and red) were analyzed, orange and red contained the greatest β-carotene and sugar contents; whereas, green fruits contained the greatest concentrations of total phenols and ascorbic acid.

Properties of low temperature belite cements made from aluminosilicate wastes by hydrothermal method

The aim of this study is the synthesis at low temperature (1000°C) of reactive belite cement, rich in reactive C2S phases (α′L and/or β-C2S), starting from aluminosilicate wastes (oil well drilling mud and hydraulic dam sludge) and hydraulic lime dust recovered from bagging workshops. A hydrothermal treatment of the raw cement mixture was performed in an alkaline solution of KOH (0.6M), with heating at 100°C for 4h under atmospheric pressure and continuous agitation. The burning of the hydrothermal mixture at 1000°C produced reactive belite cements containing between 79% and 86% of C2S (α′L and/or β polymorphs), the rest being C12A7 (5–8%), C4AF (7–11%) and free lime (2%). The cements were characterized by X-ray Fluorescence (XRF), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), microprobe, and laser granulometry. The hardening evolution of belite cement pastes and mortars was followed by thermo-gravimetric analysis (TGA), setting time and compressive strength. The results showed a rapid production of hydrates (C–S–H/C–A–S–H, calcium aluminate hydrates and portlandite), with a fast setting time (reaction of C12A7) and compressive strength evolution that led to these cements being classified in the 32.5 category according to EN 197-1.

Purification, characterization, and in vitro activity of 2,4-Di-tert-butylphenol from Pseudomonas monteilii PsF84: conformational and molecular docking studies.

A novel strain of Pseudomonas monteilii, PsF84, was isolated from tannery waste soil from Jajmau, Kanpur, India. 16S rRNA gene sequence phylogenetic analysis confirmed the taxonomic affiliation of PsF84 as P. monteilii. An antifungal volatile organic compound (VOC) active against hyphal growth of Fusarium oxysporum (CIMAP-IMI-357464) in vitro was isolated from strain PsF84 by using chromatographic techniques. The molecular formula of the antifungal VOC was deduced to be C₁₄H₂₂O by EI-MS and 1D and 2D NMR spectral analysis. 2,4-Di-tert-butylphenol was found to be effective against an agriculturally important fungus, namely, F. oxysporum, in inhibiting spore germination and hyphal growth. Molecular docking analysis of 2,4-di-tert-butylphenol with β-tubulin further validated the potential of β-tubulin binding in F. oxysporum. Two residues of β-tubulin protein, HIS 118 and THR 117, showed hydrogen binding with ligand. To the authors' knowledge, this is the first report of antifungal VOC (2,4-di-tert-butylphenol) produced by P. monteilii PsF84 that can be a potent inhibitor of β-tubulin of F. oxysporum.

Experiment of Slurry Shield Tunnel Recycling Waste Sand in Sand-Pebble Layer

Waste soil progressing in shield tunnel construction should occupy large space, on the other hand, do harm to city environment. If the waste sand in silt and fine sand layer can be used as sand source of synchronous grouting, it will bring benefits for the enterprise and society. In indoor experiment, we select waste sand in different layers, sieved as sand source, then use the waste sand to produce slurry and compare their strength with the construction slurry’s. The study found, sieved waste sand in silt and fine sand layer can be used as sand source for making synchronous grouting slurry.

동전기제염장치에서 발생한 폐액의 재사용을 위한 개선된 처리기술

우라늄으로 오염된 토양을 복원하기 위해 실규모의 동전기제염장치로 제염하는 과정에서 많은 산폐액이 발생한다. 발생한 산폐액에 CaO를 가해 우라늄수산화물을 침전시켜 여과한 다음, 방사성 폐액을 줄이기 위하여 이 용액을 재사용하였다. 그러나 이 용액을 동전기에 재사용할 경우, 높은 농도의 칼슘 때문에 양극실에서 음극실로 용액이동 속도가 감소하여 여과포의 약화, 전선 부식, 음극면에 산화물 부착 등의 문제점이 발생하였다. 이 문제들을 해결하기 위하여 재생액에 황산을 넣어 <TEX>$CaSO_4$</TEX>로 침전시켜 칼슘을 제거하였다. 칼슘이 제거된 재생액을 사용하여 소형 동전기 장치에서 20 일간 토양제염 실험을 수행한 결과는 세척후 토양내 우라늄 잔류 농도가 0.35 Bq/g로 감소하였으며, 이는 증류수 제염한 결과와 유사하게 나타났다. A large amount of acidic waste solution is generated from the practical electrokinetic decontamination equipments for the remediation of soil contaminated with uranium. After filtration of uranium hydroxides formed by adding CaO into the waste solution, the filtrate was recycled in order to reduce the volume of waste solution. However, when the filtrate was used in an electrokinetic equipment, the low permeability of the filtrate from anode cell to cathode cell due to a high concentration of calcium made several problems such as the weakening of a fabric tamis, the corrosion of electric wire and the adhension of metallic oxides to the surface of cathode electrode. To solve these problems, sulfuric acid was added into the filtrate and calcium in the solution was removed as <TEX>$CaSO_4$</TEX> precipitate. A decontamination test using a small electrokinetic equipment for 20 days indicated that Ca-removed waste solution decreased uranium concentration of the waste soil to 0.35 Bq/g, which is a similar to a decontamination result obtained by distilled water.

Exploiting the intrinsic hydrocarbon-degrading microbial capacities in oil tank bottom sludge and waste soil for sludge bioremediation

In this study, biological methods (biostimulation and bioaugmentation) were used to treat oil tank bottom sludge contaminated soils to total petroleum hydrocarbon (TPH) levels suitable for landfill disposal. The sludge’s hydrocarbon-degrading microbial capacities were initially compared to those from other contaminated environments using culture-based methods. Results indicated that a fungus, Scedosporium dominated the sludge microbial community. Its application in a nutrient formulation resulted in greater reduction in oil tank bottom sludge viscosity (44 %) and residual soil hydrocarbon compared to hydrocarbonoclastic microorganisms from other sources (26.7 % reduction in viscosity). Subsequent field-based experiments showed greater TPH reduction (54 %) in fungal-nutrient-treated sludge–waste soils than in naturally attenuated controls (22 %) over 49 days. 16S ribosomal ribonucleic acid and internal transcribed spacer region-based polymerase chain reactions and denaturing gradient gel electrophoresis analyses showed minimal effects on the microbial communities during this time. TPH reduction to landfill disposal levels occurred at a slower rate after this, falling below the 10,000 mg kg−1 legislated TPH disposal threshold earlier in amended samples (91.2 %; 9,500 mg kg−1) compared to the control (82 %; 17,000 mg kg−1) in 182 days. The results show that the intrinsic hydrocarbon-degrading microbial capacities in sludge are better suited for sludge degradation than those from other sources. The substantial TPH reduction observed in control samples demonstrates the beneficial effects of natural attenuation with waste soils for oil tank sludge treatment. Microbial capacities in sludge and treated waste soils can therefore be successfully employed for treating oil tank bottom sludge.

English

The current study was designed for the assessment of lead, cadmium and chromium and some physicochemical properties of soils collected from an open dumpsite in Yenagoa, Nigeria. Surface soil samples at two depths (0-10 and 10-20 cm) were randomly collected at the dump field and control site, and were analyzed for physicochemical parameters and contamination by lead, chromium and cadmium using standard analytical methods. The results show that the main dumpsite had higher sand (>80.0%) and lower clay and silt contents than the control site. Soil mean pH varied between 4.89±0.05 in the control and 7.60±0.02 in the dump. Total nitrogen (N) content of the dump soils ranged from 0.06±0.07 to 0.24±0.09% and is slightly higher than that of the control soil. This is reflected in the high value of organic matter (4.71±0.85%) in dump soils. Available P was quite high ranging from 35.00±1.01 to 84.20±1.02 mg/kg. Cation exchange capacity (CEC) varied between 12.98±0.31 and 91.07±0.11 cmol kg −1 . ECEC levels were moderate to high ranging from 14.10±0.10 to 91.47±0.11 cmol/kg. All the soil samples had very high base saturation (>90.0%) and exchangeable Ca, Mg, K and Na, far above the critical levels set by FAO for agricultural soil. Average levels of Pb ranged from 14.75±0.05 to 16.14±0.04 mg/kg in the dump and 8.35±0.05 to 8.78±0.07 mg/kg in the control. Mean concentration of Cr in the dump soil varied between 0.05±0.01 and 0.06±0.01 mg/kg, and is slightly higher than the control (0.005±0.01 mg/kg), while Cd was found in trace amounts (<0.0001±0.01 mg/kg). These values are all far below the maximum tolerable levels set by FAO and WHO for agricultural soil. It is suggested that the dumpsite and the control area with their adequate soil nutrients and low levels of metals should eventually be converted to agricultural farmland. No remediation is needed at this time. Keywords : Dump waste soil, heavy metal, soil fertility.

Microbial degradation of chitin waste for production of chitosanase and food related bioactive compounds.

Ecological samples rich in microbial diversity like cow dung, legume rhizosphere, fish waste and garden soil were used for isolation of chitosan-degrading microorganisms. Selected isolates were used for production of chitosanase and food related bioactive compounds by conversion of biowaste. Production of glucosamine (Gln), N-acetylglucosamine (NAG), chitooligosaccharides (COS), antioxidants, antibacterial compounds and prebiotics was carried out by microbial fermentation of biowaste. The highest chitosanase activity (8 U/mL) was observed in Aspergillus sp. isolated from fish market waste and it could produce Gln and NAG while Streptomyces sp. isolated from garden soil was able to produce COS along with Gln and NAG. Radical scavenging activity was observed in culture supernatants of 35% of studied isolates, and 20% isolates secreted compounds which showed positive effect on growth of Bifidobacterium. Antibacterial compounds were produced by 40% of selected isolates and culture supernatants of two microbial isolates, Streptomyces zaomyceticus C6 and one of garden soil isolates, were effective against both gram positive and negative bacteria.

Numerical Analysis of Safety on Waste-Dumping Cover-Slope out of the Tailings Dam

Mining companies intend to solve the problem of waste dump and reduce the production cost by dumping a large number of waste soils to cover slope outside the running tailings. Therefore, in order to discuss the safety of waste dump slope covering in front of the tailings dam, numerical method was adopted to study the seepage-line change law, the pore water pressure and anti-sliding safety before and after the waste dump covering out of tailings dam. The researches show that the key to waste-dump slope safety are the drainage performance of waste dump bottom layer and the anti-sliding safety of waste dump soil. The appropriate waste dump slope work can improves the tailings dams safety and solves the waste dump problem in mining production.

Monte Carlo calculations for dose rate at indoors exposed by distributed Cs-137 activities

The correlation of dose rates inside of the typical Japanese house to different distributions of Cs-137 activities outside are calculated by using the Monte Carlo code MVP with its attached gamma cross section library for aiming at the planning of decontamination strategies and setting the priorities in order to decrease the amounts of waste soil effectively, which will be disposed and stored for a long time with shield. The study is summarized that (1) the decontamination of the roof is not effective in decreasing the dose rate of indoors when surrounding field is contaminated, (2) the plowing of wide area will decrease the dose rate by one tenth even if the depth is only 5 cm, (3) the dose rate of the 2nd floor is higher than that of the 1st floor in some decontamination cases.

Study on the Factors and Degradation of Cellulose Degradation Bacteria

This study obtained 12 microbial degradation of cellulose from perennial accumulation of cellulose waste soil, through Congo red staining, isolated high efficient bacteria N4 degradation of cellulose. The N4 strain degradation single factor experiment showed that: carbon concentration, incubation temperature and initial pH value influence on the degradation of filter paper. Through the orthogonal experimental study obtained: when the concentration of filter paper is 0.5%, culture temperature is 30 °C, initial pH is 8, N4 strain filter paper degradation rate reached optimal, filter paper weight loss rate of 68.92%.