Free Standard AU & NZ Shipping For All Book Orders Over $80!
Register      Login
Soil Research Soil Research Society
Soil, land care and environmental research
RESEARCH ARTICLE

Speciation of nickel and enzyme activities in fluvo-aquic soil under organic amendments treatment

Borui Liu A , Qing Huang A C , Yuefeng Su A , Mengyuan Wang A , Ryan M. Kelly B and Liuye Sun A
+ Author Affiliations
- Author Affiliations

A School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China.

B Independent Scientist, California, U.S.A.

C Corresponding author. Email: huangqing3121@sina.com

Soil Research 56(5) 456-467 https://doi.org/10.1071/SR17330
Submitted: 9 December 2017  Accepted: 26 February 2018   Published: 1 June 2018

Abstract

To investigate the efficacy of humic acid and cow dung for nickel (Ni) immobilisation and detoxification in fluvo-aquic soil, the Ni-polluted soil was mixed with amendments of humic acid and cow dung. The Ni speciation (modified BCR sequential extraction method) and enzyme activities were scrutinised. As the humic acid concentration increased (0 to 12 g kg–1), the amount of Ni in the acetic acid-soluble fraction (the bioavailable fraction with high environmental risk) first decreased and then increased. In contrast, the amount of Ni in this fraction continued to decrease as the cow dung concentration increased (P < 0.05). The Ni in the acetic acid-soluble and residual fractions transformed to the oxidisable fraction, leading to lower environmental risk. The fluorescein diacetate hydrolysis and alkaline phosphatase activity were negatively correlated with the amount of Ni in the acetic acid-soluble fraction (r = –0.695 and –0.773, respectively, P < 0.01), indicating that Ni in the acetic acid-soluble fraction was toxic and led to enzyme activity inhibition, and the amendments could reduce subsequent damage. When humic acid concentration ranged from 5.01 to 6.47 g kg–1, the acetic acid-soluble Ni level reached the minimum, while the fluorescein diacetate hydrolysis and the alkaline phosphatase activity reached their maxima. In conclusion, humic acid and cow dung are effective amendments for Ni immobilisation and reduce devastation of soil enzymes. The humic acid concentration should be between 5.01 and 6.47 g kg–1 to achieve the optimum efficacy.

Additional keywords: BCR sequential extraction, chemical immobilisation, enzyme, nickel, soil pollution.


References

Ahmad M, Lee SS, Lim JE, Lee S, Cho JS, Moon DH, Hashimoto Y, Ok YS (2014) Speciation and phytoavailability of lead and antimony in a small arms range soil amended with mussel shell, cow bone and biochar: EXAFS spectroscopy and chemical extractions. Chemosphere 95, 433–441.
Speciation and phytoavailability of lead and antimony in a small arms range soil amended with mussel shell, cow bone and biochar: EXAFS spectroscopy and chemical extractions.Crossref | GoogleScholarGoogle Scholar |

Birke M, Reimann C, Rauch U, Ladenberger A, Demetriades A, Jähne-Klingberg F, Oorts K, Gosar M, Dinelli E, Halamić J, The GEMAS Project Team (2017) GEMAS: cadmium distribution and its sources in agricultural and grazing land soil of Europe – original data versus clr-transformed data. Journal of Geochemical Exploration 173, 13–30.
GEMAS: cadmium distribution and its sources in agricultural and grazing land soil of Europe – original data versus clr-transformed data.Crossref | GoogleScholarGoogle Scholar |

Bremner JM, Mulvaney RL (1978) Urease activity in soils. In ‘Soil enzymes’. (Ed. RG Burns) pp. 149–187 (Academic Press: New York)

Buekers J, Van Laer L, Amery F, Van Buggenhout S, Maes A, Smolders E (2007) Role of soil constituents in fixation of soluble Zn, Cu, Ni and Cd added to soils. European Journal of Soil Science 58, 1514–1524.
Role of soil constituents in fixation of soluble Zn, Cu, Ni and Cd added to soils.Crossref | GoogleScholarGoogle Scholar |

Cao X, Wahbi A, Ma L, Li B, Yang Y (2009) Immobilization of Zn, Cu, and Pb in contaminated soils using phosphate rock and phosphoric acid. Journal of Hazardous Materials 164, 555–564.
Immobilization of Zn, Cu, and Pb in contaminated soils using phosphate rock and phosphoric acid.Crossref | GoogleScholarGoogle Scholar |

Chang CY, Yu HY, Chen JJ, Li FB, Zhang HH, Liu CP (2014) Accumulation of heavy metals in leaf vegetables from agricultural soils and associated potential health risks in the Pearl River Delta, South China. Environmental Monitoring and Assessment 186, 1547–1560.
Accumulation of heavy metals in leaf vegetables from agricultural soils and associated potential health risks in the Pearl River Delta, South China.Crossref | GoogleScholarGoogle Scholar |

Chen L, Zhou S, Shi Y, Wang C, Li B, Li Y, Wu S (2018) Heavy metals in food crops, soil, and water in the Lihe River Watershed of the Taihu Region and their potential health risks when ingested. The Science of the Total Environment 615, 141–149.
Heavy metals in food crops, soil, and water in the Lihe River Watershed of the Taihu Region and their potential health risks when ingested.Crossref | GoogleScholarGoogle Scholar |

Choi J (2009) Adsorption, bioavailability, and toxicity of cadmium to soil microorganisms. Geomicrobiology Journal 26, 248–255.
Adsorption, bioavailability, and toxicity of cadmium to soil microorganisms.Crossref | GoogleScholarGoogle Scholar |

Duan DC (2014) Regulation mechanism of humic acid on the Pb bioavailability and toxicity to tea plants (Camellia sinensis L.). PhD Thesis, Zhejiang University, Zhejiang Province, China [In Chinese]

Evseev AV, Krasovskaya TM (2017) Toxic metals in soils of the Russian North. Journal of Geochemical Exploration 174, 128–131.
Toxic metals in soils of the Russian North.Crossref | GoogleScholarGoogle Scholar |

Fernández-Ondoño E, Bacchetta G, Lallena AM, Navarro FB, Ortiz I, Jiménez MN (2017) Use of BCR sequential extraction procedures for soils and plant metal transfer predictions in contaminated mine tailings in Sardinia. Journal of Geochemical Exploration 172, 133–141.
Use of BCR sequential extraction procedures for soils and plant metal transfer predictions in contaminated mine tailings in Sardinia.Crossref | GoogleScholarGoogle Scholar |

Gheshlaghi ZT, McLaren RG, Adams JA (2008) Effect of treated zeolite, iron waste, and liming on phytoavailability of Zn, Cu, and Ni in long-term biosolids-amended soils. Australian Journal of Soil Research 46, 509–516.
Effect of treated zeolite, iron waste, and liming on phytoavailability of Zn, Cu, and Ni in long-term biosolids-amended soils.Crossref | GoogleScholarGoogle Scholar |

Gichangi EM, Mnkeni PNS, Muchaonyerwa P (2012) Evaluation of the heavy metal immobilization potential of pine bark-based composts. Journal of Plant Nutrition 35, 1853–1865.
Evaluation of the heavy metal immobilization potential of pine bark-based composts.Crossref | GoogleScholarGoogle Scholar |

Gul S, Naz A, Khan A, Nisa S, Irshad M (2016) Phytoavailability and leachability of heavy metals from contaminated soil treated with composted livestock manure. Soil & Sediment Contamination 25, 181–194.
Phytoavailability and leachability of heavy metals from contaminated soil treated with composted livestock manure.Crossref | GoogleScholarGoogle Scholar |

Guo G, Zhou Q, Ma LQ (2006) Availability and assessment of fixing additives for the in situ remediation of heavy metal contaminated soils: a review. Environmental Monitoring and Assessment 116, 513–528.
Availability and assessment of fixing additives for the in situ remediation of heavy metal contaminated soils: a review.Crossref | GoogleScholarGoogle Scholar |

Guo XF, Wei ZB, Wu QT, Qiu JR, Zhou JL (2011) Cadmium and zinc accumulation in maize grain as affected by cultivars and chemical fixation amendments. Pedosphere 21, 650–656.
Cadmium and zinc accumulation in maize grain as affected by cultivars and chemical fixation amendments.Crossref | GoogleScholarGoogle Scholar |

Gupta S, Nayek S, Saha RN, Satpati S (2008) Assessment of heavy metal accumulation in macrophyte, agricultural soil, and crop plants adjacent to discharge zone of sponge iron factory. Environmental Geology 55, 731–739.
Assessment of heavy metal accumulation in macrophyte, agricultural soil, and crop plants adjacent to discharge zone of sponge iron factory.Crossref | GoogleScholarGoogle Scholar |

He ZL, Yang XE, Stoffella PJ (2005) Trace elements in agroecosystems and impacts on the environment. Journal of Trace Elements in Medicine and Biology 19, 125–140.
Trace elements in agroecosystems and impacts on the environment.Crossref | GoogleScholarGoogle Scholar |

Hou RX, Ouyang Z, Li YS, Tyler DD, Li FD, Wilson GV (2012) Effects of tillage and residue management on soil organic carbon and total nitrogen in the North China Plain. Soil Science Society of America Journal 76, 230–240.
Effects of tillage and residue management on soil organic carbon and total nitrogen in the North China Plain.Crossref | GoogleScholarGoogle Scholar |

Huang Q, Liu BR, Cai HJ, Bao LY (2014) Effect of freeze-thaw cycles and organic fertilizer on the speciation of cadmium in black soils. Environmental Pollution & Control 36, 38–42.
Effect of freeze-thaw cycles and organic fertilizer on the speciation of cadmium in black soils.Crossref | GoogleScholarGoogle Scholar | [In Chinese]

Impellitteri CA, Lu Y, Saxe JK, Allen HE, Peijnenburg WJ (2002) Correlation of the partitioning of dissolved organic matter fractions with the desorption of Cd, Cu, Ni, Pb and Zn from 18 Dutch soils. Environment International 28, 401–410.
Correlation of the partitioning of dissolved organic matter fractions with the desorption of Cd, Cu, Ni, Pb and Zn from 18 Dutch soils.Crossref | GoogleScholarGoogle Scholar |

Islam MS, Ahmed MK, Raknuzzaman M, Habibullah-Al-Mamun M, Kundu GK (2017) Heavy metals in the industrial sludge and their ecological risk: a case study for a developing country. Journal of Geochemical Exploration 172, 41–49.
Heavy metals in the industrial sludge and their ecological risk: a case study for a developing country.Crossref | GoogleScholarGoogle Scholar |

Jamal Khan M, Jones DL (2008) Chemical and organic immobilization treatments for reducing phytoavailability of heavy metals in copper-mine tailings. Journal of Plant Nutrition and Soil Science 171, 908–916.
Chemical and organic immobilization treatments for reducing phytoavailability of heavy metals in copper-mine tailings.Crossref | GoogleScholarGoogle Scholar |

Kataki S, Hazarika S, Baruah DC (2017) Investigation on by-products of bioenergy systems (anaerobic digestion and gasification) as potential crop nutrient using FTIR, XRD, SEM analysis and phyto-toxicity test. Journal of Environmental Management 196, 201–216.
Investigation on by-products of bioenergy systems (anaerobic digestion and gasification) as potential crop nutrient using FTIR, XRD, SEM analysis and phyto-toxicity test.Crossref | GoogleScholarGoogle Scholar |

Li J, Lu Y, Shim H, Deng X, Lian J, Jia Z, Li J (2010) Use of the BCR sequential extraction procedure for the study of metal availability to plants. Journal of Environmental Monitoring 12, 466–471.
Use of the BCR sequential extraction procedure for the study of metal availability to plants.Crossref | GoogleScholarGoogle Scholar |

Lin Y, Ma J, Zhang Z, Zhu Y, Hou H, Zhao L, Sun Z, Xue W, Shi H (2018) Linkage between human population and trace elements in soils of the Pearl River Delta: implications for source identification and risk assessment. The Science of the Total Environment 610–611, 944–950.
Linkage between human population and trace elements in soils of the Pearl River Delta: implications for source identification and risk assessment.Crossref | GoogleScholarGoogle Scholar |

Liu W, Zhou Q, Zhang Y, Wei S (2010) Lead accumulation in different Chinese cabbage cultivars and screening for pollution-safe cultivars. Journal of Environmental Management 91, 781–788.
Lead accumulation in different Chinese cabbage cultivars and screening for pollution-safe cultivars.Crossref | GoogleScholarGoogle Scholar |

Lu RK (1999) ‘Analysis methods in soil agrochemistry.’ (Chinese Agricultural Science and Technology Press: Beijing) [In Chinese]

Luo C, Liu C, Wang Y, Liu X, Li F, Zhang G, Li X (2011) Heavy metal contamination in soils and vegetables near an e-waste processing site, south China. Journal of Hazardous Materials 186, 481–490.
Heavy metal contamination in soils and vegetables near an e-waste processing site, south China.Crossref | GoogleScholarGoogle Scholar |

Ma LQ, Rao GN (1997) Chemical fractionation of cadmium, copper, nickel, and zinc in contaminated soils. Journal of Environmental Quality 26, 259–264.
Chemical fractionation of cadmium, copper, nickel, and zinc in contaminated soils.Crossref | GoogleScholarGoogle Scholar |

Maliszewska-Kordybach B, Smreczak B (2003) Habitat function of agricultural soils as affected by heavy metals and polycyclic aromatic hydrocarbons contamination. Environment International 28, 719–728.
Habitat function of agricultural soils as affected by heavy metals and polycyclic aromatic hydrocarbons contamination.Crossref | GoogleScholarGoogle Scholar |

Meissl K, Smidt E, Schwanninger M (2007) Prediction of humic acid content and respiration activity of biogenic waste by means of Fourier transform infrared (FTIR) spectra and partial least squares regression (PLS-R) models. Talanta 72, 791–799.
Prediction of humic acid content and respiration activity of biogenic waste by means of Fourier transform infrared (FTIR) spectra and partial least squares regression (PLS-R) models.Crossref | GoogleScholarGoogle Scholar |

Melamed R, Cao X, Chen M, Ma LQ (2003) Field assessment of lead immobilization in a contaminated soil after phosphate application. The Science of the Total Environment 305, 117–127.
Field assessment of lead immobilization in a contaminated soil after phosphate application.Crossref | GoogleScholarGoogle Scholar |

Nannipieri P (1995) The potential use of soil enzymes as indicators of productivity, sustainability and pollution. In ‘Soil biota: management in sustainable farming system’. (Eds CE Pankhurst, BM Doube, VVSR Gupta, PR Grace) pp. 238–244. (CSIRO: East Melbourne, Victoria, Australia)

Narwal RP, Singh BR (1998) Effect of organic materials on partitioning, extractability and plant uptake of metals in an alum shale soil. Water, Air, and Soil Pollution 103, 405–421.
Effect of organic materials on partitioning, extractability and plant uptake of metals in an alum shale soil.Crossref | GoogleScholarGoogle Scholar |

Ojuri OO, Taiwo OA, Oluwatuyi OE (2016) Heavy metal migration along a rural highway route: Ilesha-Akure roadside soil, Southwestern, Nigeria. Global NEST Journal 18, 742–760.

Opatokun SA, Kan T, Al Shoaibi A, Srinivasakannan C, Strezov V (2016) Characterization of food waste and its digestate as feedstock for thermochemical processing. Energy & Fuels 30, 1589–1597.
Characterization of food waste and its digestate as feedstock for thermochemical processing.Crossref | GoogleScholarGoogle Scholar |

Pathak C, Chopra AK, Srivastava S (2013) Accumulation of heavy metals in Spinacia oleracea irrigated with paper mill effluent and sewage. Environmental Monitoring and Assessment 185, 7343–7352.
Accumulation of heavy metals in Spinacia oleracea irrigated with paper mill effluent and sewage.Crossref | GoogleScholarGoogle Scholar |

Quina MJ, Lopes DV, Cruz LG, Andrade J, Martins RC, Gando-Ferreira LM, Dias-Ferreira C, Quinta-Ferreira RM (2015) Studies on the chemical stabilisation of digestate from mechanically recovered organic fraction of municipal solid waste. Waste and Biomass Valorization 6, 711–721.
Studies on the chemical stabilisation of digestate from mechanically recovered organic fraction of municipal solid waste.Crossref | GoogleScholarGoogle Scholar |

Raj T, Kapoor M, Gaur R, Christopher J, Lamba B, Tuli DK, Kumar R (2015) Physical and chemical characterization of various Indian agriculture, residues for biofuels production. Energy & Fuels 29, 3111–3118.
Physical and chemical characterization of various Indian agriculture, residues for biofuels production.Crossref | GoogleScholarGoogle Scholar |

Rauret G, López-Sánchez JF, Sahuquillo A, Rubio R, Davidson C, Ure A, Quevauviller P (1999) Improvement of the BCR three step sequential extraction procedure prior to the certification of new sediment and soil reference materials. Journal of Environmental Monitoring 1, 57–61.
Improvement of the BCR three step sequential extraction procedure prior to the certification of new sediment and soil reference materials.Crossref | GoogleScholarGoogle Scholar |

Redman AD, Macalady DL, Ahmann D (2002) Natural organic matter affects arsenic speciation and sorption onto hematite. Environmental Science & Technology 36, 2889–2896.
Natural organic matter affects arsenic speciation and sorption onto hematite.Crossref | GoogleScholarGoogle Scholar |

Regelink IC, Temminghoff EJM (2011) Ni adsorption and Ni-Al LDH precipitation in a sandy aquifer: an experimental and mechanistic modeling study. Environmental Pollution 159, 716–721.
Ni adsorption and Ni-Al LDH precipitation in a sandy aquifer: an experimental and mechanistic modeling study.Crossref | GoogleScholarGoogle Scholar |

Rinklebe J, Shaheen SM, Frohne T (2016) Amendment of biochar reduces the release of toxic elements under dynamic redox conditions in a contaminated floodplain soil. Chemosphere 142, 41–47.
Amendment of biochar reduces the release of toxic elements under dynamic redox conditions in a contaminated floodplain soil.Crossref | GoogleScholarGoogle Scholar |

Rodríguez L, Ruiz E, Alonso-Azcárate J, Rincón J (2009) Heavy metal distribution and chemical speciation in tailings and soils around a Pb–Zn mine in Spain. Journal of Environmental Management 90, 1106–1116.
Heavy metal distribution and chemical speciation in tailings and soils around a Pb–Zn mine in Spain.Crossref | GoogleScholarGoogle Scholar |

Rosen V, Chen Y (2014) The influence of compost addition on heavy metal distribution between operationally defined geochemical fractions and on metal accumulation in plant. Journal of Soils and Sediments 14, 713–720.
The influence of compost addition on heavy metal distribution between operationally defined geochemical fractions and on metal accumulation in plant.Crossref | GoogleScholarGoogle Scholar |

Rupiasih NN, Vidyasagar PB (2009) Analytical study of humic acid from various sources commonly used as fertilizer: emphasis on heavy metal content. International Journal of Design & Nature and Ecodynamics 4, 32–46.
Analytical study of humic acid from various sources commonly used as fertilizer: emphasis on heavy metal content.Crossref | GoogleScholarGoogle Scholar |

Sabir M, Ali A, Zia-Ur-Rehman M, Hakeem KR (2015) Contrasting effects of farmyard manure (FYM) and compost for remediation of metal contaminated soil. International Journal of Phytoremediation 17, 613–621.
Contrasting effects of farmyard manure (FYM) and compost for remediation of metal contaminated soil.Crossref | GoogleScholarGoogle Scholar |

Saffari M, Karimian N, Ronaghi A, Yasrebi J, Ghasemi-Fasaei R (2015) Stabilization of nickel in a contaminated calcareous soil amended with low-cost amendments. Journal of Soil Science and Plant Nutrition 15, 896–913.

Schmidt M, Goebeler M (2011) Nickel allergies: paying the toll for innate immunity. Journal of Molecular Medicine 89, 961–970.
Nickel allergies: paying the toll for innate immunity.Crossref | GoogleScholarGoogle Scholar |

Schnürer J, Rosswall T (1982) Fluorescein diacetate hydrolysis as a measure of total microbial activity in soil and litter. Applied and Environmental Microbiology 43, 1256–1261.

Shrivastava A, Barla A, Singh S, Mandraha S, Bose S (2017) Arsenic contamination in agricultural soils of Bengal deltaic region of West Bengal and its higher assimilation in monsoon rice. Journal of Hazardous Materials 324, 526–534.
Arsenic contamination in agricultural soils of Bengal deltaic region of West Bengal and its higher assimilation in monsoon rice.Crossref | GoogleScholarGoogle Scholar |

Siebers N, Kruse J, Leinweber P (2013) Speciation of phosphorus and cadmium in a contaminated soil amended with bone char: sequential fractionations and XANES spectroscopy. Water, Air, and Soil Pollution 224, 1564–1576.
Speciation of phosphorus and cadmium in a contaminated soil amended with bone char: sequential fractionations and XANES spectroscopy.Crossref | GoogleScholarGoogle Scholar |

Spaccini R, Piccolo A (2008) Spectroscopic characterization of compost at different maturity stages. Clean – Soil, Air, Water 36, 152–157.
Spectroscopic characterization of compost at different maturity stages.Crossref | GoogleScholarGoogle Scholar |

Tabatabai MA, Bremner JM (1969) Use of p-nitrophenyl phosphate for assay of soil phosphatase activity. Soil Biology & Biochemistry 1, 301–307.
Use of p-nitrophenyl phosphate for assay of soil phosphatase activity.Crossref | GoogleScholarGoogle Scholar |

Tian X, Tian C, Nie Y, Dai C, Yang C, Tian N, Zhou Z, Li Y, Wang Y (2018) Controlled synthesis of dandelion-like NiCo2O4 microspheres and their catalytic performance for peroxymonosulfate activation in humic acid degradation. Chemical Engineering Journal 331, 144–151.
Controlled synthesis of dandelion-like NiCo2O4 microspheres and their catalytic performance for peroxymonosulfate activation in humic acid degradation.Crossref | GoogleScholarGoogle Scholar |

Wang M, Markert B, Shen W, Chen W, Peng C, Ouyang Z (2011a) Microbial biomass carbon and enzyme activities of urban soils in Beijing. Environmental Science and Pollution Research International 18, 958–967.
Microbial biomass carbon and enzyme activities of urban soils in Beijing.Crossref | GoogleScholarGoogle Scholar |

Wang WQ, Zhao XL, Luo YL, Shi C, Ma H, Yu X, Jia HT (2011b) Infrared spectral analysis during fermentation of cattle manure. China Cattle Science 37, 15–19.
Infrared spectral analysis during fermentation of cattle manure.Crossref | GoogleScholarGoogle Scholar | [In Chinese]

Wasay SA, Barrington S, Tokunaga S (2001) Organic acids for the in situ remediation of soils polluted by heavy metals: soil flushing in columns. Water, Air, and Soil Pollution 127, 301–314.
Organic acids for the in situ remediation of soils polluted by heavy metals: soil flushing in columns.Crossref | GoogleScholarGoogle Scholar |

Wieczorek K, Wyszkowska J (2015) Sensitivity of soil urease to soil contamination by zinc, copper, nickel, cadmium and lead. Fresenius Environmental Bulletin 24, 2496–2504.

Wieczorek K, Wyszkowska J, Kucharski J (2014) Influence of zinc, copper, nickel, cadmium and lead in soils on acid phosphatase activity. Fresenius Environmental Bulletin 23, 274–284.

Yan CS (1988) ‘Research method of soil fertility.’ (Agriculture Press: Beijing) [In Chinese]

Yang H, Turner S, Rose NL (2016) Mercury pollution in the lake sediments and catchment soils of anthropogenically-disturbed sites across England. Environmental Pollution 219, 1092–1101.
Mercury pollution in the lake sediments and catchment soils of anthropogenically-disturbed sites across England.Crossref | GoogleScholarGoogle Scholar |

Zambelli B, Ciurli S (2013) Nickel and human health. Metal Ions in Life Sciences 13, 321–357.
Nickel and human health.Crossref | GoogleScholarGoogle Scholar |

Zambelli B, Uversky VN, Ciurli S (2016) Nickel impact on human health: an intrinsic disorder perspective. Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics 1864, 1714–1731.
Nickel impact on human health: an intrinsic disorder perspective.Crossref | GoogleScholarGoogle Scholar |

Zeng LS, Liao M, Chen CL, Huang CY (2007) Effects of lead contamination on soil enzymatic activities, microbial biomass, and rice physiological indices in soil-lead-rice (Oryza sativa L.) system. Environmental Science & Technology 67, 67–74.

Zhang P, Ryan JA (1999) Formation of chloropyromorphite from galena (PbS) in the presence of hydroxyapatite. Environmental Science & Technology 33, 618–624.
Formation of chloropyromorphite from galena (PbS) in the presence of hydroxyapatite.Crossref | GoogleScholarGoogle Scholar |

Zhang Z, Solaiman ZM, Meney K, Murphy DV, Rengel Z (2013) Biochars immobilize soil cadmium, but do not improve growth of emergent wetland species Juncus subsecundus in cadmium-contaminated soil. Journal of Soils and Sediments 13, 140–151.
Biochars immobilize soil cadmium, but do not improve growth of emergent wetland species Juncus subsecundus in cadmium-contaminated soil.Crossref | GoogleScholarGoogle Scholar |

Zheng N, Wang Q, Zheng D (2007) Health risk of Hg, Pb, Cd, Zn, and Cu to the inhabitants around Huludao Zinc Plant in China via consumption of vegetables. The Science of the Total Environment 383, 81–89.
Health risk of Hg, Pb, Cd, Zn, and Cu to the inhabitants around Huludao Zinc Plant in China via consumption of vegetables.Crossref | GoogleScholarGoogle Scholar |