土壤及地下水之重金屬普遍存在於地殼表面，經人為活動及經濟快速發展下，使得重金屬污染逐漸延散開來，近年以來許多重金屬污染事件頻傳，其中，重金屬污染物質以八大金屬(砷、鎘、汞、鉻、銅、鎳、鉛、鋅)為主，常存在於土壤表層或地下含水層，使得整治上困難度更難。本研究場址是以生物整治復育技術處理台南某受鉻酸鹽污染之地下水進行批次試驗結果及探討，本實驗選擇微生物較為豐富、易吸收之營養基質(Nutrient broth, NB)及培養馴化之當地菌群，期望本研究以本地之地下水馴化培養方式並篩選出當地鉻酸鹽還原菌做為生物強化(bioaugmentation)技術促進現地生物處理技術效果。本研究以生物批次試驗來評估各研究組別生物降解能力及菌相之差異特性，最後以生物技術進行聚合酶鏈鎖反應(Polymerase chain reaction, PCR)、變性梯度膠體電泳(Denaturing gradient gel electrophoresis, DGGE)及生物定序(Biological Sequencing)分析瞭解整體菌相多樣性與定序結果探討菌種。微生態試驗組別以控制組(Control)、自然降解組(IG)、營養添加(IN)及植菌組(IBN)做為研究操作，依研究結果顯示，各組別之六價鉻還原效率以IBN組為最佳，在137天試驗中可穩定降解92.44%之高濃度六價鉻污染物，殘留濃度為2.37 mg/L，雖然尚未符合地下水污染管制標準(0.50 mg/L)，但仍持續有生物降解趨勢情形發生。由結果顯示，微生物降解IN及IBN組的酸鹼值(pH)介於7.5 – 9.0之間，非常適合微生物生長之環境條件。由批次實驗中，定期監測IG、IN及IBN組別之六價鉻污染物及總溶解性有機碳(Total dissolved organic carbon, TDOC)皆呈現下降趨勢，表示微生物有持續利用碳源的情況；然而，溶氧(DO)及氧化還原電位(ORP)在監測期間有發現部份上升趨勢，根據早期許多學者研究指出微生物在還原六價鉻的過程，會產生活性氧化類物質(Reactive oxygen species, ROS)，導致含氧物質(例如，氧離子(oxygen ion, O2-)及過氧化氫(peroxide, H2O2))破壞微生物細胞體，造成生物抑制作用。實驗過程以六價鉻(Cr6+)及總鉻(Total Cr)間關係，並配合環境掃描顯微鏡/X光微區分析(SEM/EDAX)觀測下，證實微生物批次組別有發生物沈澱現象及生物膠狀現象。最後，由菌相分析及菌種定序結果證實IBN組所添加本地馴化菌種，除了可以有效提高鉻酸鹽抵抗性，更能顯著提高六價鉻的還原能力，此外，由菌相DGGE分析結果亦顯示，IBN能提高現地環境中鉻酸鹽菌之豐富度。依定序結果篩選出16種針對現地具有還原六價鉻之菌種，如α-proteobacteria有5種Alpha proteobacterium、Acetobacteraceae bacterium、Caulobacterales bacterium、Enterobacter sp.及Rhodospirillales bacterium；β-proteobacteria有7種Beta proteobacterium、Dechloromonas sp.、Propionivibrio sp.、Rhodocyclaceae bacterium、Rhodocyclales bacterium、Methyloversatilis sp.及Nitrosomonadales bacterium；則γ-proteobacteria有4種，如Enterobacteriales bacterium、Gamma proteobacterium、Prokaryote bacterium及Psychrobacter sp.等。本研究所採用之生物整治復育技術具備優點有：(1)解決現地場址地下環境微生物缺乏的問題；(2)容易與其他整治工法結合整治；(3)現地馴化微生物耐金屬及還原目標污染物特性強；(4)對於場址整治較友善及永續；(5)水體檸檬酸生物淋洗劑緩衝能力強，能適宜控制地下生物環境酸化問題。
由以上結果顯示，本研究利用馴化鉻酸鹽還原菌(Chromate reducing bacteria, CRB)不僅能有效在有毒六價鉻環境生長，且經過馴化培養及提供現地微生物營養基質，而催化微生物活性，強化現地還原六價鉻及促進生物沈澱效果，符合綠色整治之理念。

In recent years, soil and groundwater contaminated by heavy metals (e.g., arsenic, cadmium, mercury, chromium, copper, nickel, lead, zinc) have become a serious environmental problem. In this study, microcosm experiments were conducted using enriched contaminated groundwater as the inocula to evaluate the feasibility of applying the reduction process to remediation chromate contaminated groundwater. Each microcosm contained enriched bacteria broth, cromate, groundwater, and nutrient broth. Kill and live control microcosms were also prepared for comparison. Molecular biotechnology methods including polymerase chain reaction (PCR), denaturing gradient gel electrophoresis (DGGE), and biological sequencing analysis were applied to determine the dominant bacteria and microbial diversity. Results show that up to 92% of hexavalent chromium (HCr) reduction efficiency was observed after 137 days of incubation. The pH ranged from 7.5 to 9.0. The reduction of total organic carbon (TOC) indicates that the carbon source was consumed by the bacteria. Slight increase of the oxidation-reduction potential (ORP) was observed during the operation. This could be due to the occurrence of microbial reduction of hexavalent chromium, which produced oxidizing substances (reactive oxygen species, ROS). Thus, oxygen-containing species (e.g., oxygen ion (oxygen ion, O2-) and hydrogen peroxide (H2O2)) might damage the anaerobic bacteria cell body and resulted in the inhibition of biological process. Results also confirmed that the occurrence of biological precipitation and biocolloid examined by environmental scanning microscope/X ray microanalysis (SEM/EDAX). Results from the microbial diversity analyses show that the acclimated bacteria could resist high cromate concentration with high cromate reduction ability. Results from the DGGE and sequence analyses show that there were 16 dominant intrinsic bacteria had the chromate reduction ability. The α-proteobacteria contained Alpha proteobacterium, Acetobacteraceae bacterium, Caulobacterales bacterium, Enterobacter sp. and Rhodospirillales bacterium. The β-proteobacteria contained Beta proteobacterium, Dechloromonas sp., Propionivibrio sp., Rhodocyclaceae bacterium, Rhodocyclales bacterium, Methyloversatilis sp., and Nitrosomonadales bacterium. The γ-proteobacteria contained Enterobacteriales bacterium, Gamma proteobacterium, Prokaryote bacterium, and Psychrobacter sp. The isolated chromate reducing bacteria (CRB) could grow well under the high chromate conditions. Moreover, CRB could effectively reduce the chromate toxicity after the reduction process. The biological reduction process meets the requirement of green remediation.

論文審定書 i
致謝 ii
中文摘要 iii
ABSTRACT v
總目錄 vii
圖目錄 x
表目錄 xii
第一章 前言 1
1-1研究緣起 1
1-2研究目的 2
第二章 文獻回顧 4
2-1地下水之鉻酸鹽污染來源 4
2-2鉻酸鹽化合物 5
2-2-1鉻酸鹽之物化特性 5
2-2-2鉻酸鹽化合物之毒理及危害性 10
2-2-3鉻酸鹽在水體中之傳輸與流佈 15
2-2-4鉻酸鹽之污染案例介紹 17
2-2-5鉻酸鹽於各國之管制近況趨勢 19
2-2-6鉻酸鹽於國內之使用近況 22
2-3鉻酸鹽土壤及地下水整治技術 27
2-3-1鉻酸鹽污染場址物理/化學整治技術 29
2-3-2鉻酸鹽污染場址熱處理技術 31
2-4生物整治法 37
2-4-1生物處理技術簡介 37
2-4-2生物處理技術之整治運用 41
2-4-3生物處理技術之種類與優缺點 45
2-5鉻酸鹽菌之介紹 49
2-5-1鉻酸鹽菌特性及分類(CHARACTERISTIC OF CHROMATE BACTERIA AND CLASSIFICATION) 49
2-5-2鉻酸鹽還原菌( CHROMATE REDUCING BACTERIA, CRB ) 57
2-5-3鉻酸鹽耐受菌( CHROMATE TOLERANCE/RESISTANCE BACTERIA, CTB ) 65
第三章 研究方法 69
3-1研究架構 69
3-2研究材料與儀器設備 70
3-2-1試驗所需藥品 70
3-2-2儀器設備 72
3-3試驗地下水之介紹 74
3-3-1目前場址營運狀況 74
3-3-2場址革沿 76
3-3-3污染情形 78
3-4研究試驗方法及設計 80
3-4-1地下水基本性質分析 80
3-4-2研究設計與組別 83
3-5試驗分析與檢測之方法 86
3-5-1生物還原沈澱產物分析 86
3-5-2微生物特性分析 87
第四章 結果與討論 95
4-1地下水基本性質分析 95
4-1-1地下水特性及濃度分析 95
4-2微生物細胞酶還原六價鉻之影響 97
4-2-1地下水中六價鉻降解趨勢 97
4-2-2以一階反應探討探討六價鉻生物還原與去除率 100
4-2-3 各試驗參數與微生物之關聯性探討 102
4-2-4 生物沈澱之表面特性 110
4-3 批次試驗之微生物豐富度及識別 117
4-3-1 各試驗組別之菌相分析(PCR) 117
4-3-2 批次試驗組別之菌相鑑定 118
4-3-3 批次試驗組別之豐富度分析(DGGE) 121
4-4 綜合論述 128
4-4-1生物加強式(AUTOCHTHONOUS BIOAUGMENTATION)復育之操作建議流程圖 128
第五章 結論與建議 134
5-1 結論 134
5-2 建議 136
參考文獻 137
中文文獻(CHINESE REFERENCE) 137
英文文獻(ENGLISH REFERENCE) 141

大紀元[1] (EPOCH TIMEZ). (2015).
at: http://www.epochtimes.com/b5/tag/+鉻污染.html
環境資源中心網站[2] (環資中心網). (2015).
at: http://e-info.org.tw/taxonomy/term/36694
行政院環保署新聞專區[3] . (2015).
at: http://enews.epa.gov.tw/enews/fact_index.asp
土污基管會. (2015). 土壤及地下水污染品質查詢.
at: http://sgw.epa.gov.tw/public/ContaminatedSitesMap/Default.aspx
行政院環保署土壤及地下水污染整治基金管理. (2013). 土壤及地下水污染整治十年有成專刊(第三章 整治技術介紹).
at: http://sgw.epa.gov.tw/public/Action_index.asp
行政院環保署之水質淨化現地處理網站. (2015a)
at: http://wqp.epa.gov.tw/ecological/ClassRoom.aspx?Num=01
行政院環保署毒管處. (2015).
at: http://www.epa.gov.tw/mp.asp?mp=epa
行政院環保署毒管處之毒理資料庫規範. (2015).
at: http://flora2.epa.gov.tw/_ToxicWeb/toxicuc4/database.aspx
財團法人工業技術研究院能源與環境研究所. (2006). 毒性化學物質重金屬類物種鑑識技術 (EPA-95-E3S3-02-01).
at: http://www.epa.gov.tw/public/Attachment/43311551070.pdf
國家環境毒物研究中心. (2014). 環境毒物研究中心整理之口服六價鉻毒性資料.
at:http://nehrc.nhri.org.tw/toxic/ref/Chromium20141107.pdf
 
經濟部工業局. (2006). 重金屬−土壤及地下水污染預防與整治手冊.
at: http://proj.ftis.org.tw/eta/publish/technology.asp?HnfiuI0C8KtiyF8mt24TMx
環境資源中心網站(環資中心網). (2015). 毒米樂！躲摸摸！農村再生上天堂！及嘉義農田遭重金屬污染地上物將銷毀.
at: http://e-info.org.tw/taxonomy/term/14973
江姿幸, 及高志明. (2005). 滲透性反應牆對於砷污染土壤進行電動力法復育影響之研究. 中山大學環境工程研究所, 1-176.
何建仁. (2012). 我國土壤及地下水污染整治之未來發展方向, 工業污染防治, (121), 89.
吳正宗, 及王百晟. (2012). 肥培資材重金屬含量調查, 興大農業之環境、農業資材與農糧食品中之重金屬, (82).
吳勇興, 及陳信榮. (2012). 從美國的土壤篩選基準制定方式看我國的土壤鉻污染管制標準. 中興工程, (117), 23-30.
吳培堯, 劉沛宏, 許益源, 陳怡君, 及楊致. (2007). 鉻酸場址整治, (22), 4 – 8.
呂政信, 及單信瑜. (2013). 現地透水性反應牆配置對含氯有機溶劑整治效率的影響 . 交通大學土木工程系所學位論文, 1-118.
李俊錡, 及董瑞安. (2010). 零價矽結合重金屬離子降解四氯乙烯還原脫氯反應之研究. 清華大學生醫工程與環境科學系學位論文, 1-184.
林佩雲, 林正浩, 林淑滿, 及鍾裕仁. (2013). 現地氧化工程之快速監測方法開發.中興工程, (120), 120-123..
林佳燕, 蔡義誌, 及林俐玲. (2009). 土壤粒徑分析實驗方法之比較. Journal of Soil and Water Conservation, 41(2), 139-152.
林財富. (2008). 土壤及地下水污染整治:原理與應用. 台灣土壤及地下水環境保護協會簡訊, (28).
施英隆. (2013). 環境化學.(ISBN：9789571120096),五南出版社.
 
美商傑明工程顧問 (股) 台灣分公司, 及行政院環境保護署. (2011). 土壤及地下水重金屬與無機陰離子污染物污染場址之整治技術選取、系統設計要點與操作維護注意事項參考手冊.營運中含鉛製程事業之土壤污染潛勢調查計畫.
高宇. (2009). 分子生物學(上)研究所AE4019(二版)(ISBN：9789862261538)
屠明明, 及王秋玉. (2009). 石油污染土壤的生物刺激和生物强化修复. 中國生物工程雜誌, 29(8), 129-134.
梁書豪, 簡華逸, 郭育嘉, 楊宗翰, 及高志明. (2012). 土壤及地下水整治技術發展簡介。
郭魁士, 「土壤學」, 中國書局印行, 臺北, (1997), 115-116。
陳文福, 呂學諭, 及劉聰桂. (2010). 台灣地下水之氧化還原狀態與砷濃度. 農業工程學報, 56 (2): 57-70.
陳谷汎, 及高志明. (2002). 土壤及地下水物理/化學復育技術. 台灣土壤及地下水環境保護協會簡訊, (5) 3-5.
陳尊賢. (2003). 受重金屬污染農地土壤之整治技術與相關問題分析. 台灣土壤及地下水環境保護簡訊, (9), 2-9.
陳福勝, 陳卓然, 及林志誠. (2001). 土壤及地下水污染處理總論(譯自T.M.J. Ngu and J.A. Xu., 2000).
黃俊嘉, 2004, 以土耕法結合生物堆法處理受柴油污染之土壤, 國立中山大學環境工程研究所.
黃智, 吳勇興, 林淑滿,及鍾裕仁. (2011). 土壤清洗技術於土壤污染整治應用. 中興工程, (110), 53-61.
楊磊, 鄭秀珍, 及吳裕民. (2007). 以植物復育技術整治中石化(台鹼)安順場址污染土壤可行性之評估研究，中石化(台鹼)安順場址土壤及底泥整治技術研討會。
劉志忠, 及曾迪華. (2006). 零價鐵反應牆應用於三氯乙烯還原脫氯之整合研究. 中央大學環境工程研究所學位論文, 1-215.
 
劉振宇. (2002). 氧化／還原下之現地生物整治. 台灣土壤及地下水環境保護簡訊, (5), 3-5.
蔡在唐. (2008). 利用整治列車系統處理含氯有機物污染之地下水. 台灣土壤及地下水環境保護協會簡訊, (28), 3-15.
盧至人. (2002). 現地生物復育技術. 台灣土壤及地下水環境保護協會簡訊, (5), 3-5.
盧至人. (2004). 地下水現地生物復育和廢污水生物處理的特性探討.台灣土壤及地下水環境保護簡訊, (14), 7-15
蘇紹瑋, 及陳尊賢. (2008). 土壤清洗法整治重金屬污染土壤國內外最新研究與整治案例之回顧.台灣土壤及地下水環境保護簡訊, (27),4-12.
ATSDR, (2012). Chromium - ToxFAQs™.(CAS NO. 7440-47-3), Agency for Toxic Substances and Disease Registr.
at: http://www.atsdr.cdc.gov/toxfaqs/tfacts7.pdf
Chromium (VI) Compounds, IARC, (1973).
at: http://monographs.iarc.fr/ENG/Monographs/vol100C/mono100C-9.pdf
USEPA, 2000, Chromium Compounds.
at: http://www.epa.gov/ttnatw01/hlthef/chromium.html
USEPA. (1998). Toxicological Review for ChromiumVI, CAS NO. 18540-29-9, U.S. Environmental Protection Agency.
at: www.epa.gov/iris/toxreviews/0144-tr.pdf
Ackerley, D.F., Gonzalez, C.F., Keyhan, M., Blake, and R., Matin, A., (2004). Mechanism of chromate reduction by the Escherichia coli protein, NfsA, and the role of different chromate reductases in minimizing oxidative stress during chromate reduction. Environmental Microbiology, 6(8), 851-860.
Agnieszka, J., and Barbara, G. (2012). Chromium, nickel and vanadium mobility in soils derived from fluvioglacial sands. Journal of Hazardous Materials, 237, 315-322.
AMOOZEGAR, M.A., GHASEMI, A., RAZAVI, M.R. and NADDAF, S. (2007). Evaluation of hexavalent chromium reduction by chromate-resistant moderately halophile, Nesterenkonia sp. strain MF2. Process Biochemistry, 42(10), 1475-1479.
APHA (American Public Health Association), AWWA (American Water Works Association), and WEF (Water Environment Federation). (1995). Standard Methods for the Examination of Water and Wastewater, 19th edition, Washington, DC.
Apte, A. D., Tare, V., and Bose, P. (2006). Extent of oxidation of Cr (III) to Cr (VI) under various conditions pertaining to natural environment. Journal of Hazardous Materials, 128(2), 164-174.
Asmatulla, S., Qureshi N., and Shakoori A. R., (1998). Hexavalent chromium induced congenital abnormalities in chick embryos. Journal of Applied Toxicology, 18, 167-172.
Atlas, R. M., & Bartha, R. (1973). Stimulated biodegradation of oil slicks using oleophilic fertilizers. Environmental Science and Technology, 7(6), 538-541.
 
Aulenta, F., Majone, M. and Tandoi, V. (2006) Enhanced anaerobic bioremediation of choorinated solvents: environmental factors influencing microbial activity and their relevance under field conditions. Journal of Chemical Technology and Biotechnology, 81, 1463-1474.
Bank, T. L., Vishnivetskaya, T. A., Jardine, P. M., Ginder-Vogel, M. A., Fendorf, S., and Baldwin, M. E. (2007). Elucidating biogeochemical reduction of chromate via carbon amendments and soil sterilization. Geomicrobiology Journal, 24(2), 125-132.
Barak, Y., Ackerley, D. F., Dodge, C. J., Banwari, L., Alex, C., Francis, and A. J., and Matin, A., (2006). Analysis of novel soluble chromate and uranyl reductases and generation of an improved enzyme by directed evolution. Applied and Environmental Microbiology, 72(11), 7074-7082.
Barrera-Díaz, C.E., Lugo-Lugo, V., and Bilyeu, B. (2012). Review: a review of chemical, electrochemical and biological methods for aqueous Cr(VI) reduction. Journal of Hazardous Materials, 223, 1-12.
Bartlett, R. J. (1991). Chromium cycling in soils and water: links, gaps, and methods. Environmental Health Perspectives, 92, 17-24
Baruthio, F. (1992). Toxic effects of chromium and its compounds. Biological Trace Element Research, 32(1-3), 145-153.
Beaumont, J. J., Sedman, R. M., Reynolds, S. D., Sherman, C. D., Li, L. H., Howd, R. A., Sandy, M. S., Zeise, L., Alexeeff, G. V. (2008). Cancer mortality in a Chinese population exposed to hexavalent chromium in drinking water. Epidemiology, 19(1), 12-23.
Bedient, P. B., Rifai, H. S., and Newell, C.J. (1999). Ground water contamination: transport and remediation. (ISBN-13: 978-0130138408).
Bednar, C.M., Kies, C. (1991) Inorganic contaminants in drinking water correlated with disease occurrence in Nebraska. Water Resour Bull, 27(4):631–635.
Bencheikh-Latmani, R., Obraztsova, A., Mackey, M. R., Ellisman, M. H., and Tebo, B. M. (2007). Toxicity of Cr (III) to Shewanella sp. strain MR-4 during Cr (VI) reduction. Environmental Science and Technology, 41(1), 214-220.
Blum, P., Sagner, A., Tiehm, A., Martus, P., Wendel, T., and Grathwohl, P. (2011). Importance of heterocylic aromatic compounds in monitored natural attenuation for coal tar contaminated aquifers: A review. Journal of Contaminant Hydrology, 126(3), 181-194.
Bopp, L. H., Ehrlich, H. L., (1988). Chromate resistance and reduction in Pseudomonas fluorescens strain LB300. Archives of Microbiology, 150(5), 426-431.
 
Borden, R. C., and Kao, C. M. (1992). Evaluation of Groundwater Extraction for Remediation of Petroleum Contaminated Aquifers. Water Environment Research, 64, No. 1.
Bougherira, N., Hani, A., Djabri, L., Sedrati, N., Haied, N., and Toumi, F. (2014). Mobility of Chromium and Tin Associated with Geochemical Dynamics in Groundwater in Meboudja Plain. Energy Procedia, 50, 685-691.
Brodie, E. L., Joyner, D. C., Faybishenko, B., Conrad, M. E., Rios-Velazquez, C., Malave, J., Martinez R., Mork B., Willett A., Koenigsberg S., Herman D., Firestone M. K., and Hazen, T. C. (2011). Microbial community response to addition of polylactate compounds to stimulate hexavalent chromium reduction in groundwater. Chemosphere, 85(4), 660-665.
Cetin, Z., Kantar, C., and Alpaslan, M., (2009). Interactions between uronic acids and chromium(III). Environmental Toxicology and Chemistry, 28(8), 1599-1608.
Chakraborty, B., Indra, S., Hazra, D., Betai, R., Ray, L., and Basu, S. (2013). Performance study of chromium (VI) removal in presence of phenol in a continuous packed bed reactor by Escherichia coli isolated from east Calcutta wetlands. BioMed research international.
Chardin, B., Giudici-Orticoni, M. T., De Luca, G., Guigliarelli, B., and Bruschi, M., (2003). Hydrogenases in sulfate-reducing bacteria function as chromium reductase. Applied Microbiology and Biotechnology, 63(3), 315-321.
Chatterjee, S., Ghosh, I., and Mukherjea, K. K. (2011). Uptake and removal of toxic Cr (VI) by Pseudomonas aeruginosa: physico-chemical and biological evaluation. Current Science(Bangalore), 101(5), 645-652.
Chen, J., Tang, Y. Q., and Wu, X. L. (2012). Bacterial community shift in two sectors of a tannery plant and its Cr (VI) removing potential. Geomicrobiology Journal, 29(3), 226-235.
Chen, K. F., Kao, C. M., Zhang, W. X., and Chen, T. Y. (2006). Natural attenuation of a MTBE plume at an oil-refining site. Abstracts of Papers - American Chemical Society, 231, 170 .
Cheung, K. H., and Gu, J. D., (2007). Mechanism of hexavalent chromium detoxification by microorganisms and bioremediation application potential: a review. International Biodeterioration and Biodegradation, 59(1), 8-15.
Chi, Y. H., Paeng, S. K., Kim, M. J., Hwang, G. Y., Melencion, S. M. B., Oh, H. T., and Lee, S. Y. (2013). Redox-dependent functional switching of plant proteins accompanying with their structural changes. Frontiers in Plant Science,4.
 
Chung, J., Ryu, H., Abbaszadegan, M., and Rittmann, B. E. (2006). Community structure and function in a H2-based membrane biofilm reactor capable of bioreduction of selenate and chromate. Applied Microbiology and Biotechnology, 72(6), 1330-1339.
Codd, R., Irwin J. A., and Lay P. A. (2003). Sialoglycoprotein and carbohydrate complexes in chromium toxicity. Current Opinion in Chemical Biology, 7(2), 213-219.
Coleman, R.N., (1988). Chromium toxicity: effects on microorganisms with special reference to the soil matrix. Chromium in Natural and Human Environments, 335-350.
Contreras, E. M., Orozco, A. F., and Zaritzky, N. E. (2011). Biological Cr (VI) removal coupled with biomass growth, biomass decay, and multiple substrate limitation. Water Research, 45(10), 3034-3046.
Das, S., Mishra, J., Das, S. K., Pandey, S., Rao, D. S., Chakraborty, A., Sudarshan, M., Das, N. N., and Thatoi, H. N. (2014). Investigation on mechanism of Cr(VI) reduction and removal by Bacillus amyloliquefaciens, a novel chromate tolerant bacterium isolated from chromite mine soil. Chemosphere, 96, 112-121.
Das, S., Ram, S. S., Sahu, H. K., Rao, D. S., Chakraborty, A., Sudarshan, M., Thatoi, H. N. (2013). A study on soil physico-chemical, microbial and metal content in Sukinda chromite mine of Odisha, India. Environmental Earth Sciences, 69(8), 2487-2497.
de M Bandeira, S., da Fonseca, L. J. S., da S Guedes, G., Rabelo, L. A., Goulart, M. O., and Vasconcelos, S. M. L. (2013). Oxidative stress as an underlying contributor in the development of chronic complications in diabetes mellitus. International Journal of Molecular Sciences, 14(2), 3265-3284.
Declercq, I., Cappuyns, V., Duclos, Y. (2012). Monitored natural attenuation (MNA) of contaminated soils: State of the art in Europe-A critical evaluation. Science of the Total Environment, 426, 393-405.
Dermatas, D., Mpouras, T., Chrysochoou, M., Panagiotakis, I., Vatseris, C., Linardos, N., Theologou E., Boboti N., Xenidis A., Papassiopi N., and Sakellariou, L. (2015). Origin and concentration profile of chromium in a Greek aquifer. Journal of Hazardous Materials, 281, 35-46.
Dhal, B., Thatoi, H., Das, N., and Pandey, B. D. (2010). Reduction of hexavalent chromium by Bacillus sp. isolated from chromite mine soils and characterization of reduced product. Journal of Chemical Technology and Biotechnology, 85(11), 1471-1479.
Dietz, K. J. (2003). Redox control, redox signaling, and redox homeostasis in plant cells. International Review of Cytology, 228, 141-193.
Divyasree, P., Braun, J. J., and Subramanian, S. (2014). Comparative Studies on the Bioremediation of Hexavalent and Trivalent Chromium using Citrobacter freundii: Part I-Effect of parameters controlling Biosorption. International Journal of Environmental Research, 8(4), 1227-1134.
Dworkin, M., and Falkow, S. (2006). The Prokaryotes: A Handbook on the Biology of Bacteria. Springer Science and Business Media.
Eastmond, D. A., MacGregor, J. T., and Slesinski, R. S. (2008). Trivalent chromium: assessing the genotoxic risk of an essential trace element and widely used human and animal nutritional supplement. Critical Reviews in Toxicology, 38(3), 173-190.
Eizaguirre-Garcia, D., Rodriguez-Andres, C., Watt, G. C. (2000). Congenital anomalies in Glasgow between 1982 and 1989 and chromium waste. Journal of Public Health, 22(1), 54-58.
Eizaguirre-Garcia, D., Rodriguez-Andres, C., Watt, G. C., and Hole D. (1999). A study of leukaemia in Glasgow in connection with chromium-contaminated land. Journal of Public Health, 21(4), 435-438.
Elangovan, R., Philip, L., Chandraraj, K. (2010). Hexavalent chromium reduction by free and immobilized cell-free extract of Arthrobacter rhombi-RE. Applied Biochemistry and Biotechnology, 160(1), 81-97.
Farhadian, M., Vachelard, C., Duchez, D., & Larroche, C. (2008). In situ bioremediation of monoaromatic pollutants in groundwater: a review. Bioresource Technology, 99(13), 5296-5308.
Ford, R. G., Wilkin, R. T., Paul, C. J., Beck, F., Lee, T., Scheckel, K. G., & Clark, P. (2005). Field study of the fate of arsenic, lead, and zinc at the ground-water/surface-water Interface.
Fryzek, J. P., Mumma, M. T., McLaughlin, J. K., Henderson B. E., and Blot W. J. (2001). Cancer mortality in relation to environmental chromium exposure. Journal of Occupational and Environmental Medicine, 43(7), 635-640.
Fuji, E., Toda, K., and Ohtake, H. (1990). Bacterial reduction of toxic hexavalent chromium using a batch-fed culture of Enterobacter clocae strain HOI. Journal of Fermentation and Bioengineering, 69(6), 365-367.
Garavaglia, L., Cerdeira, S. B., and Vullo, D. L. (2010). Chromium (VI) biotransformation by β-and γ-Proteobacteria from natural polluted environments: a combined biological and chemical treatment for industrial wastes. Journal of Hazardous Materials, 175(1), 104-110.
Gong, X., Li, W., Wang, K., and Hu, J. (2013). Study of the adsorption of Cr (VI) by tannic acid immobilised powdered activated carbon from micro-polluted water in the presence of dissolved humic acid. Bioresource Technology, 141, 145-151.
 
Grevatt, P. C. (1998). Toxicological review of hexavalent chromium. Support of Summary Information on the Integrated Risk Information System (IRIS), US Environmental Protection Agency Washington DC, US.
Hanson, A., DeMouche, L., Lesikar, B., and Dreager, A. (2013). Onsite wastewater management: a manual for tribes. NM State University, Cooperative Extension Service.
Hendrick, J. P., and Hartl, F. U. (1993). Molecular chaperone functions of heat-shock proteins. Annual Review of Biochemistry, 62(1), 349-384.
Hinchee, R. E., and Olfenbuttel, R. F. (2013). In situ bioreclamation: applications and investigations for hydrocarbon and contaminated site remediation. (ISBN: 978-0-7506-9301-1), Elsevier.
Hussein, H., Farag, S., Kandil, K., and Moawad, H. (2005). Tolerance and uptake of heavy metals by Pseudomonads. Process Biochemistry, 40(2), 955-961.
Huang, L., Yu, C. H., Hopke, P. K., Lioy, P. J., Buckley, B. T., Shin, J. Y., and Fan, Z. (2014). Measurement of soluble and total hexavalent chromium in the ambient airborne particles in New Jersey. Aerosol and Air Quality Research, 14, 1939-1949.
Ibrahim, A. S., El-Tayeb, M. A., Elbadawi, Y. B., and Al-Salamah, A. A. (2011). Isolation and characterization of novel potent Cr (VI) reducing alkaliphilic Amphibacillus sp. KSUCr3 from hypersaline soda lakes. Electronic Journal of Biotechnology, 14(4), 4-4.
International Agency for Research on Cancer, & International Agency for Research on Cancer. (1990). Chromium, nickel and welding. IARC monographs on the evaluation of carcinogenic risks to humans, 49.
Ishibashi, Y., Cervantes, C., and Silver, S. (1990). Chromium reduction in Pseudomonas putida. Applied and Environmental Microbiology, 56(7), 2268-2270.
James, B. R., Petura, J. C., and Vitale, R. J. (1997). Oxidation-Reduction Chemistry of Chromium: Relevance to the Regulation and Remediation of Chromate-Contaminated Soils. Journal of Soil and Sediment Contamination, 6(6), 569-580.
Jorge‐Araújo, P., Quiquampoix, H., Matumoto‐Pintro, P. T., and Staunton, S. (2015). Glomalin‐related soil protein in French temperate forest soils: interference in the Bradford assay caused by co‐extracted humic substances. European Journal of Soil Science, 66(2), 311-319.
Kaksonen, A. (2004). The performance, kinetics and microbiology of sulfidogenic fluidized-bed reactors treating acidic metal-and sulfate-containing wastewater. Tampereen Teknillinen yliopisto, Julkaisu. 489 and Publication. 489.
 
Kalin, R. M. (2005). In-Situ bioremediation of cyanide, PAHs and organic compounds using engineered sequenced reactive barrier (SEREBAR) techniques： a progress report 0 to 14 months. In: CL:AIRE Annual Project Conference, (Unversity College, London, 20 April, 2004).
Kanmani, P., Aravind, J., and Preston, D. (2012). Remediation of chromium contaminants using bacteria. International Journal of Environmental Science and Technology, 9(1), 183-193.
Kao C. M., and Borden R. C. (1994). Enhanced Aerobic bioremdiation of a gasline contaminated aquifer by oxygen-releasing barriers. Hydrocarbon Bioremediation. Boca Raton: Lewis Publishers, 262-266.
Kao, C. M, Chien H. Y., and Surampalli R. Y. (2010a). Assessing of Natural Attenuation and Intrinsic Bioremediation Rates at a Petroleum Hydrocarbon Spill Site: Laboratory and Field Studies. Journal of Environmental Engineering, 136(1), 54-67.
Kao, C. M., Chien, H. Y., Surampalli, R. Y., Chien, C. C., and Chen, C. Y. (2010b). Assessing of Natural Attenuation and Intrinsic Bioremediation Rates at a Petroleum-Hydrocarbon Spill Site: Laboratory and Field Studies. Journal of Environmental Engineering, 136(1), 54-67.
Kao, C. M., Huang, W. Y., Chang, L. J., Chen, T. Y., Chien, H. Y., and Hou, F. (2006). Application of monitored natural attenuation to remediate a petroleum-hydrocarbon spill site. Water Science and Technology, 53(2), 321-328.
Kao, C. M., Huang, W. Y., Chang, L. J., Chen, T. Y., Chien, H. Y., and Hou, F. (2006). Application of monitored natural attenuation to remediate a petroleum-hydrocarbon spill site. Water Science and Technology, 53(2), 321-328.
Kathiravan, M. N., Karthick, R., Muthu, N., Muthukumar, K., and Velan, M. (2010). Sonoassisted microbial reduction of chromium. Applied Biochemistry and Biotechnology, 160(7), 2000-2013.
Katsaveli, K., Vayenas, D., Tsiamis, G., and Bourtzis, K. (2012). Bacterial diversity in Cr (VI) and Cr (III)-contaminated industrial wastewaters. Extremophiles, 16(2), 285-296.
Kerger, B. D., Butler, W. J., Paustenbach, D. J., Zhang, J., and Li, S. (2011). Oral ingestion of hexavalent chromium through drinking water and cancer mortality in an industrial area of Greece - An ecological study. Environmental Health 10(1),50
Kerger, B. D., Butler, W. J., Paustenbach, D. J., Zhang, J., Li, S. (2009). Cancer mortality in Chinese populations surrounding an alloy plant with chromium smelting operations. Journal of Toxicology and Environmental Health, Part A, 72(5), 329-344.
 
Kotaś, J., and Stasicka, Z. (2000). Chromium occurrence in the environment and methods of its speciation. Environmental pollution, 107(3), 263-283.
Langwaldt, J. H., and Puhakka, J. A. (2000). On-site biological remediation of contaminated groundwater: a review. Environmental pollution, 107(2), 187-197.
Li, B., Pan, D., Zheng, J., Cheng, Y., Ma, X., Huang, F., and Lin, Z. (2008). Microscopic investigations of the Cr (VI) uptake mechanism of living Ochrobactrum anthropi. Langmuir, 24(17), 9630-9635.
Liu, X., Wu, G., Zhang, Y., Wu, D., Li, X., and Liu, P. (2015). Chromate Reductase YieF from Escherichia coli Enhances Hexavalent Chromium Resistance of Human HepG2 Cells. International Journal of Molecular Sciences, 16(6), 11892-11902.
Liu, Y. G., Xu, W. H., Zeng, G. M., Li, X., Gao, H. (2006). Cr (VI) reduction by Bacillus sp. isolated from chromium landfill. Process Biochem. 41(9), 1981-1986.
Lonergan, D. J., Jenter, H., Coates, J. D., Phillips, E. J. P., Schmidt, T., Lovely, D. R. (1996). Phylogenetic analysis of dissimilatory Fe(III) reducing bacteria. Journal of Bacteriology, 178(8), 2402-2408.
Lourenço, R. F., and Gomes, S. L. (2009). The transcriptional response to cadmium, organic hydroperoxide, singlet oxygen and UV‐A mediated by the σE–ChrR system in Caulobacter crescentus. Molecular Microbiology, 72(5), 1159-1170.
Lovely, D. R. (1995). Bioremediation of organic and metal contaminates with dissimilatory metal reduction. Journal of Industrial Microbiology, 14(2), 85-93.
Lovley, D. R., Coates, J. D., Saffarini, D. A., Lonergan, D. J., and Winkelman, C. J. (1997). Iron and Related Transition Metals in Microbial Metabolism. Harwood Academic Publishers, Switzerland, 187-215.
Lovley, D. R., Phillips, J. P. E. (1994). Reduction of chromate by Desulfovibrio vulgaris and its C3 cytochrome. Applied and Environmental Microbiology, 60(2), 726-728.
Ma, Z., Zhu, W., Long, H., Chai, L., and Wang, Q. (2007). Chromate reduction by resting cells of Achromobacter sp. Ch-1 under aerobic conditions. Process Biochemistry, 42(6), 1028-1032.
Margesin, R., and Schinner, F. (2001). Potential of halotolerant and halophilic microorganisms for biotechnology. Extremophiles, 5(2), 73-83.
Martins, M., Faleiro, M. L., Chaves, S., Tenreiro, R., Santos, E., and Costa, M. C. (2010). Anaerobic bio-removal of uranium (VI) and chromium (VI): comparison of microbial community structure. Journal of Hazardous Materials, 176(1), 1065-1072.
Masood, F., and Malik, A. (2011). Hexavalent chromium reduction by Bacillus sp. strain FM1 isolated from heavy-metal contaminated soil. Bulletin of Environmental Contamination and Toxicology, 86(1), 114-119.
McCullough, J., Hazen, T. C., Benson, S. M., Metting, F. B., and Palmisano, A. C. (1999). Bioremediation of Metals and Radionuclides. Office of Biological and Environmental Research, US Department of Energy, Germantown, Md.
McIlvaine, T. C. (1921). A buffer solution for colorimetric comparison. Journal of Biological Chemistry, 49(1), 183-186.
McLean, J., Beveridge, T. J. (2001). Chromate reduction by a pseudomonad isolated from a site contaminated with chromated copper arsenate. Applied and Environmental Microbiology, 67(3), 1076-1084.
McLean, J., Beveridge, T. J., Phipps, D. (2000). Isolation and characterization of a chromium-reducing bacterium from a chromate copper arsenate contaminated site. Environmental Microbiology, 2(6), 611-619.
Miranda, A. T., Gonzalez, M. V., Gonzalez, G., Vargas, E., Campos-Garcia, J., Cervantes, C. (2005). Involvement of DNA helicases in chromate resistance by Pseudomonas aeruginosa PAO1. Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis, 578(1), 202-209.
Mishra, R. R., Dhal, B., Dutta, S. K., Dangar, T. K., Das, N. N., and Thatoi, H. N. (2012). Optimization and characterization of chromium (VI) reduction in saline condition by moderately halophilic Vigribacillus sp. isolated from mangrove soil of Bhitarkanika. India. Journal of Hazardous Materials, 227, 219-226.
Morais, P. V., Branco, R., Francisco, R. (2011). Chromium resistance strategies and toxicity: what makes Ochrobactrum tritici 5bvl1 a strain highly resistant. Biometals, 24(3), 401-410.
Mulligan, C. N., Yong, R. N., Gibbs, B. F. (2001). Surfactant-enhanced remediation of contaminated soil: a review. Engineering Geology, 60(1), 371-380.
Myers, C. R., Carstens, B. P., Antholine, W. E., Myers, J. M. (2000). Chromium (VI) reductase activity is associated with the cytoplasmic membrane of anaerobically grown Shewanella putrefaciens MR-1. Journal of Applied Microbiology, 88(1), 98-106.
National Research Council. (1993). Insitu Bioremediation, National Academy Press, MD, 207.
National Toxicology Program. (2008). Toxicology and carcinogenesis studies of sodium dichromate dihydrate (Cas No. 7789-12-0) in F344/N rats and B6C3F1 mice (drinking water studies). National Toxicology Program technical report series, (546), 1.
 
Ngwenya, N., Chirwa, E. M. N. (2011). Biological removal of cationic fission products from nuclear wastewater. Water Science and Technology, 63(1), 124.
Orozco, A. F., Contreras, E. M., and Zaritzky, N. E. (2010). Cr (VI) reduction capacity of activated sludge as affected by nitrogen and carbon sources, microbial acclimation and cell multiplication. Journal of Hazardous Materials,176(1), 657-665.
Orozco, A. M. F., Contreras, E. M., Bertola, N. C., and Zaritzky, N. E. (2007). Hexavalent chromium removal using aerobic activated sludge batch systems added with powdered activated carbon. Water Sa, 33(2).
Pan, X., Liu, Z., Chen, Z., Cheng, Y., Pan, D., Shao, J., Lin, Z., and Guan, X. (2014). Investigation of Cr (VI) reduction and Cr (III) immobilization mechanism by planktonic cells and biofilms of Bacillus subtilis ATCC-6633. Water Research,55, 21-29.
Panichev, N., Mabasa, W., Ngobeni, P., Mandiwana, K., and Panicheva, S. (2008). The oxidation of Cr (III) to Cr (VI) in the environment by atmospheric oxygen during the bush fires. Journal of Hazardous Materials, 153(3), 937-941.
Parmar, A. N., Oosterbroek, T., Del Sordo, S., Segreto, A., Santangelo, A., Dal Fiume, D., and Orlandini, M. (2000). Broad-band BeppoSAX observation of the low-mass X-ray binary X1822-371. arXiv preprint astro-ph/0001407.
Patra, R.C., Malik, B., Beer, M., Megharaj, M., and Naidu, R. (2010). Molecular characterization of chromium (VI) reducing potential in gram positive bacteria isolated from contaminated sites. Soil Biology and Biochemistry, 42(10), 1857-1863.
Pei, Q. H., Shahir, S., and Santhana, A. S. (2009). Chromium (VI) resistance and removal by Acinetobacter haemolyticus. World Journal of Microbiology and Biotechnology, 25(6), 1085-1093.
Pieper, D. H., Martins dos Santos, V. A., Golyshin, P. N. (2004). Genomic and mechanistic insight into the biodegradation of organic pollutants. Current Opinion in Biotechnology, 15(3), 215-224.
Polti, M. A., Amoroso, M. J., Abate, C. M. (2011). Intracellular chromium accumulation by Streptomyces sp. MC1. Water, Air, and Soil Pollution, 214(1-4), 49-57.
Priester, J. H., Olson, S. G., Webb, S. M., Neu, M. P., Hersman, L. E., and Holden, P. A. (2006). Enhanced exopolymer production and chromium stabilization in Pseudomonas putida unsaturated biofilms. Applied and Environmental Microbiology, 72(3), 1988-1996.
 
Priester, J. H., Olson, S. G., Webb, S. M., Neu, M. P., Hersman, L. E., Holden, P. A. (2006). Enhanced exopolymer production and chromium stabilization in Pseudomonas putida unsaturated biofilms. Applied and Environmental Microbiology, 72(3), 1988-1996.
Prigione, V., Zerlottin, M., Refosco, D., Tigini, V., Anastasi, A., and Varese, G. C. (2009). Chromium removal from a real tanning effluent by autochthonous and allochthonous fungi. Bioresource Technology, 100(11), 2770-2776.
Puls, R. W. (1999). An In-situ Permeable Reactive Barrier for the Treatment of Hexavalent Chromium and Trichloroethylene in Ground Water ( 1). US Environmental Protection Agency. National Risk Management Research Laboratory.
Puzon, G. J., Petersen, J. N., Roberts, A. G., Kramer, D. M., and Xun, L. (2002). A bacterial flavin reductase system reduces chromate to a soluble chromium (III)–NAD+ complex. Biochemical and Biophysical Research Communications, 294(1), 76-81.
Puzon, G. J., Robert, A. G., Kramer, D. M., and Xun, L. (2005). Formation of soluble organo-Cr(III) complexes after chromate reduction in the presence of cellular organics. Environmental Science and Technology, 39(8), 2811-2817.
Quilntana, M., Curutchet, G., Donati, E. (2001). Factors affecting chromium (VI) reduction by Thiobacillus ferrooxidans. Biochemical Engineering Journal, 9(1), 11-15.
Ramirez-Diaz, M. I., Diaz-Perez, C., Vargas, E., Riveros-Rosas, H., Campo-Garcia, J., and Cervantes, C. (2008). Mechanisms of Bacterial Resistance to Chromium Compounds. Biometals, 21(3), 321-332.
Rao, M. A., Scelza, R., Scotti, R., and Gianfreda, L. (2010). Role of enzymes in the remediation of polluted environments. Journal of Soil Science and Plant Nutrition, 10(3), 333-353.
Romaneko, V. I., and Korenkov, V. N. (1975). Bacterial reduction of ions. Inform. Byul. Inta Biol. Vnutr. Vod. Akad. Nauk SSR 25, 8.
Ruggaber, T. P., Talley, J. W. (2006). Enhancing bioremediation with enzymatic processes: a review. Pract. Period. Hazard. Toxic, and Radioactive Waste Management., (10), 73-85.
Schmieman, E. A., Yonge, D. R., Rege, M. A., Petersen, J. N., Turick, C. E., Apel, W. A. (1998). Comparative kinetics of bacterial reduction of chromium. Journal of Environmental Engineering, 124(5), 449-455.
Shen, H., and Wang, Y. T. (1993). Characterization of enzymatic reduction of hexavalentchromium by Escherichia coli ATCC 33456. Applied and Environmental Microbiology, 59(11), 3771-3777.
Shi, X., and Dalal, N. S. (1994). Generation of hydroxyl radical by chromate in biologically relevant systems: role of Cr (V) complexes versus tetraperoxochromate (V). Environmental Health Perspectives, 102(Suppl 3), 231.
Singh, R., Misra, V., and Singh, R. P. (2011). Synthesis, characterization and role of zero valent iron nanoparticle in removal of hexavalent chromium from chromium spiked soil. Journal of Nanoparticle Research, 13(9), 4063-4073.ISO 690
Smith, W. L., and Gadd, G. M. (2000). Reduction and precipitation of chromate by mixed culture sulfate reducing bacterial biofilm. Journal of Applied Microbiology, 88(6), 983-991.
Soni, S. K., Singh, R., Awasthi, A., Singh, M., and Kalra, A. (2012). In vitro Cr (VI) reduction by cell-free extracts of chromate-reducing bacteria isolated from tannery effluent irrigated soil. Environmental Science and Pollution Research, 20(3), 1661-1674.
Stewart, D. I., Burke, I. T., and Mortimer, R. J. G. (2007). Stimulation of microbially mediated chromate reduction in alkaline soil-water systems. Geomicrobiology Journal, 24(7-8), 655-669.
Strandberg, J., Odén, H., Nieto, R. M., Björk, A. (2011). Treatment of Dioxin Contaminated Soils — literature review and method development. IVL report B1993.
Sultan, S., and Hasnain, S. (2005). Reduction of toxic hexavalent chromium by Ochrobactrum intermedium strain SDCr-5 stimulated by heavy metals. Bioresource Technology, 98(2), 340-344.
Sutherland, T. D., Horne, I., Weir, K. M., Coppin, C. W., Williams, M. R., Selleck, M., Russell, R. J., and Oakeshott, J. G. (2004). Enzymatic bioremediation: from enzyme discovery to applications. Clinical and Experimental Pharmacology and Physiology, 31(11), 817-821.
Tekerlekopoulou, A., Tsiamis, G., Dermou, E., Siozios, S., Bourtzis, K., Vayenas, D. V. (2010). The effect of carbon source on microbial community structure and Cr(VI) reduction rate. Biotechnology and Bioengineering 107 (3), 478-487.
Thacker, U., Parikh, R., Shouche, Y., and Madamwar, D. (2006). Hexavalent chromium reduction by Providencia sp. Process Biochemistry, 41(6), 1332-1337.
Thatoi, H., Das, S., Mishra, J., Rath, B. P., and Das, N. (2014). Bacterial chromate reductase, a potential enzyme for bioremediation of hexavalent chromium: A review. Journal of Environmental Management, 146, 383-399.
Thatoi, H., Das, S., Mishra, J., Rath, B. P., and Das, N. (2014). Bacterial chromate reductase, a potential enzyme for bioremediation of hexavalent chromium: A review. Journal of Environmental Management, 146, 383-399.
 
Turick, C. E., Apel, W. A., and Carmiol, N. S. (1996). Isolation of hexavalent chromiumcontaminated and non-contaminated environments. Applied and Microbiology Biotechnoogy, 44 (5), 683-688.
Tyagi, M., da Fonseca, M. M. R., and de Carvalho, C. C. (2011). Bioaugmentation and biostimulation strategies to improve the effectiveness of bioremediation processes. Biodegradation, 22(2), 231-241.
Wang, P. C., Mori, T., Komori, K., Sasatsu, M., Toda, K., and Ohtake, H. (1989). Isolation and characterization of an Enterobacter cloacae strain that reduces hexavalent chromium under anaerobic conditions. Applied and Environmental Microbiology, 55(7), 1665-1669.
Wang, P. C., Mori, T., Toda, K., and Ohtake, H. (1990). Membrane-associated chromate reductase activity from Enterobacter cloacae. Journal of Bacteriology, 172(3), 1670-1672.
Wang, P. C., Toda, K., Ohtake, H., Kusaka, I., and Yabe, I. (1991). Membrane-bound respiratory system of Enterobacter cloacae strain HO1 grown anaerobically with chromate. FEMS Microbiol. Lett. 78 (1), 11-15.
Wang, Q., Cissoko, N., Zhou, M., and Xu, X. (2011). Effects and mechanism of humic acid on chromium (VI) removal by zero-valent iron (Fe0) nanoparticles. Physics and Chemistry of the Earth, Parts A/B/C, 36(9), 442-446.
Wang, X., Son, Y. O., Chang, Q., Sun, L., Hitron, J. A., Budhraja, A., Zhang, Z., Ke, Z., Chen, F., Luo, J., and Shi, X. (2011). NADPH oxidase activation is required in reactive oxygen species generation and cell transformation induced by hexavalent chromium. Toxicological Sciences, 123(2), 399-410.
Wang, Y. T., and Shen, H. (1995). Bacterial reduction of hexavalent chromium. Journal of Industrial Microbiology, 14(2), 159-163.
Whiteley, C. G., and Lee, D. J. (2006). Enzyme technology and biological remediation. Enzyme and Microbial Technology, 38(3), 291-316.
Wilkin, R. T., Acree, S. D., Beak, D. G., Ross, R. R., Lee, T. R., and Paul, C. J. (2008). Field Application of a Permeable Reactive Barrier for Treatment of Arsenic in Ground Water. National Risk Management Research Laboratory, Office of Research and Development US Environmental Protection Agency.
Wilkin, R. T., and Puls, R. W. (2004). Evaluation of permeable reactive barrier performance. EPA/542/R-04/004. Washington, DC: U.S.EPA.
Williams, P. J., Botes, E., Maleke, M. M., Ojo, A., DeFlaun, M. F., Howell, J., Borch, R., Jordan, R., and van Heerden, E. (2014). Effective bioreduction of hexavalent chromium–contaminated water in fixed-film bioreactors. Water SA, 40(3), 549-554.
 
Qi, Y.(2007). Microbial diversity associated with metal-and radionuclide-contamination at the DOE Savannah River Site (SRS), South Carolina, USA(Doctoral dissertation, University of Georgia).
Zhang, J., and Li, S. (1997). Cancer mortality in a Chinese population exposed to hexavalent chromium in water. Journal of Occupational and Environmental Medicine, 39(4), 315-319.
Zhang, J., and Li, X. (1987). Chromium pollution of soil and water in Jinzhou. Zhonghua yu fang yi xue za zhi [Chinese Journal of Preventive Medicine], 21(5), 262.
Zheng, Z., Li, Y., Zhang, X., Liu, P., Ren, J., Wu, G., Zhang Y., Chen Y., and Li, X. (2015). A Bacillus subtilis strain can reduce hexavalent chromium to trivalent and an nfrA gene is involved. International Biodeterioration and Biodegradation, 97, 90-96.
Zhitkovich, A. (2011). Chromium in drinking water: sources, metabolism, and cancer risks. Chemical Research in Toxicology, 24(10), 1617-1629.
Zoetendal, E. G., Heilig, H. G., Klaassens, E. S., Booijink, C. C., Kleerebezem, M., Smidt, H., and De Vos, W. M. (2006). Isolation of DNA from bacterial samples of the human gastrointestinal tract. Nature Protocols, 1(2), 870-873.
Zuriaga-Agustí, E., Galiana-Aleixandre, M. V., Bes-Piá, A., Mendoza-Roca, J. A., Risueño-Puchades, V., and Segarra, V. (2015). Pollution reduction in an eco-friendly chrome-free tanning and evaluation of the biodegradation by composting of the tanned leather wastes. Journal of Cleaner Production, 87, 874-881.