Hcmute nghiên cứu xử lý nước kim loại nặng trong nước thải xi mạ bằng pellet reactor

BỘ GIÁO DỤC VÀ ĐÀO TẠO TRƯỜNG ĐẠI HỌC SƯ PHẠM KỸ THUẬT THÀNH PHỐ HỒ CHÍ MINH CƠNG TRÌNH NGHIÊN CỨU KHOA HỌC CẤP TRƯỜNG NGHIÊN CỨU XỬ LÝ NƯỚC KIM LOẠI NẶNG TRONG NƯỚC THẢI XI MẠ BẰNG PELLET REACTOR MÃ SỐ: T2018-35TĐ SKC 0 Tp Hồ Chí Minh, tháng 04/2019 Luan van BỘ GIÁO DỤC VÀ ĐÀO TẠO TRƯỜNG ĐẠI HỌC SƯ PHẠM KỸ THUẬT THÀNH PHỐ HỒ CHÍ MINH BÁO CÁO TỔNG KẾT ĐỀ TÀI KH&CN CẤP TRƯỜNG TRỌNG ĐIỂM NGHIÊN CỨU XỬ LÝ NƯỚC KIM LOẠI NẶNG TRONG NƯỚC THẢI XI MẠ BẰNG PELLET REACTOR Mã số: T2018-35TĐ Chủ nhiệm đề tài: TS Trần Thị Kim Anh TP HCM, 04/2019 Luan van TRƯỜNG ĐẠI HỌC SƯ PHẠM KỸ THUẬT THÀNH PHỐ HỒ CHÍ MINH KHOA CƠNG NGHỆ HĨA HỌC & THỰC PHẨM BÁO CÁO TỔNG KẾT ĐỀ TÀI KH&CN CẤP TRƯỜNG TRỌNG ĐIỂM NGHIÊN CỨU XỬ LÝ NƯỚC KIM LOẠI NẶNG TRONG NƯỚC THẢI XI MẠ BẰNG PELLET REACTOR Mã số: T2018-35TĐ Chủ nhiệm đề tài: TS Trần Thị Kim Anh Thành viên đề tài: TS Hoàng Thị Tuyết Nhung TP HCM, 04/2019 Luan van DANH SÁCH THÀNH VIÊN THAM GIA NGHIÊN CỨU STT TÊN THÀNH VIÊN ĐƠN VỊ QUẢN LÝ TS Hồng Thị Tuyết Khoa CN Hóa học Thực phẩm, trường ĐH Nhung SPKT TPHCM Luan van MỤC LỤC DANH MỤC HÌNH I DANH MỤC BẢNG .II DANH MỤC TỪ VIẾT TẮT III THÔNG TIN KẾT QUẢ NGHIÊN CỨU IV CHƯƠNG MỞ ĐẦU I Tổng quan nghiên cứu nước II Tính cấp thiết đề tài III Mục tiêu nghiên cứu IV Nội dung nghiên cứu V Đối tượng phạm vi nghiên cứu VI Ý nghĩa nghiên cứu VII Phương pháp nghiên cứu CHƯƠNG 1: TỔNG QUAN NGHIÊN CỨU 1.1 Vấn đề môi trường 1.2 Các phương pháp xử lý độ cứng kim loại nặng 1.3 Lý thuyết Bể phản ứng tầng sôi 12 CHƯƠNG 2: PHƯƠNG PHÁP NGHIÊN CỨU 15 2.1 Vật liệu thiết bị 15 2.2 Vận hành mơ hình 15 2.2.1 Khảo sát hiệu xử lý nước cứng 16 2.2.2 Khảo sát hiệu loại bỏ kim loại nặng 19 2.3 Phân tích mẫu 19 CHƯƠNG 3: KẾT QUẢ BÀN LUẬN 20 3.1 Hiệu loại bỏ độ cứng 20 3.1.1 Ảnh hưởng tỉ lệ mol [CO32−]/[Ca2+] đến hiệu khử canxi 20 3.1.2 Ảnh hưởng vận tốc nước lên đến hiệu khử canxi 21 3.1.3 Ảnh hưởng kích cỡ hạt cát khối lượng đến hiệu xử lý 22 3.1.4 Ảnh hưởng nồng độ canxi đầu vào 24 3.2 Hạt sau xử lý 25 3.3 Loại bỏ canxi kim loại nặng kết hợp 27 CHƯƠNG 4: KẾT LUẬN KIẾN NGHỊ 29 4.1 Kết luận 29 4.2 Kiến nghị 30 TÀI LIỆU THAM KHẢO viii Luan van MỤC LỤC DANH MỤC HÌNH DANH MỤC BẢNG VÀ HÌNH ẢNH DANH MỤC BẢNG Bảng 2.1: Thành phần tính chất nước thải xi mạ ……….………………………… 15 Bảng 2.2: Điều kiện vận hành ……………………………………………………….19 Bảng 3.1: Tổng hợp kết chụp XRD …………………………………………….25 DANH MỤC HÌNH Hình 1: Hình dạng bể Bể phản ứng tầng sơi ………………………………… 16 Hình 2: Sơ đồ lắp đặt thiết bị hệ thống PR …………… ………………17 Hình 1: Ảnh hưởng của[CO32−]/[Ca2+) đến hiệu loại bỏ canxi nồng độ Canxi = 550 mgCaCO3/L (HRT = phút)…… 20 Hình 2: Ảnh hướng vận tốc nước lên đến hiệu loại bỏ canxi (a) chất rắn lơn lửng (b)…………………………………………………………………… 22 Hình 3: Ảnh hưởng kích cỡ hạt đến khả loại bỏ canxi………………… 23 Hình 4: Ảnh hưởng khối lượng hạt đến khả loại bỏ canxi……………… 24 Hình 5: Ảnh hưởng nồng độ Canxi đến hiệu loại bỏ canxi…………… … 24 Hình 6: Đồ thị biểu diễn kết chụp XRD hai mẫu cát……………………… 25 Hình 7: Kết chụp SEM……………………….…………… .26 I Luan van DANH MỤC TỪ VIẾT TẮT PR KLN UNEP SEM XRD Pellet reactor (Bể phản ứng tầng sôi ) Kim loại nặng Chương trình Mơi trường Liên hợp quốc Scanning electron microscopes X-ray Diffraction II Luan van TRƯỜNG ĐẠI HỌC SƯ PHẠM KỸ THUẬT CỘNG HOÀ XÃ HỘI CHỦ NGHĨA VIỆT NAM THÀNH PHỐ HỒ CHÍ MINH Độc lập - Tự - Hạnh phúc Khoa CN Hóa học & Thực phẩm Tp HCM, ngày 02 tháng 04 năm 2019 THÔNG TIN KẾT QUẢ NGHIÊN CỨU Thông tin chung Tên đề tài: Nghiên cứu xử lý kim loại nặng nước thải xi mạ mơ hình pellet reactor Mã số: T2018-35TĐ Chủ nhiệm: TS Trần Thị Kim Anh Cơ quan chủ trì: Đại học Sư phạm Kỹ thuật Thành phố Hồ Chí Minh Thời gian thực hiện: 03/2018-03/2019 Mục tiêu Nghiên cứu khả loại bỏ độ cứng Canxi kim loại nặng nước thải xi mạ mơ hình Bể phản ứng tầng sơi thay đổi pH, lưu lượng lượng cát Tính sáng tạo Sử dụng mơ hình Bể phản ứng tầng sơi với đặc điểm nhỏ gọn với chi phí vận hành thấp để xử lý nước thải đồng thời giảm thiểu lượng chất thải khó phân hủy thải bỏ ngồi mơi trường Kết nghiên cứu Khả loại bỏ (Ca2+ kim loại nặng) từ nước thải với hiệu suất lên đến 80% loại bỏ Canxi nồng độ lên đến 200 ppm nickel đến 90% nồng độ đầu vào 40 ppm, ứng dụng tốt mơ hình xử lý nước thải xi mạ Sản phẩm Báo cáo khoa học, mơ hình Bể phản ứng tầng sơi phịng thí nghiệm Hiệu quả, phương thức chuyển giao kết nghiên cứu khả áp dụng Sản phẩm nghiên cứu sản phẩm ứng dụng cho cơng nghệ xử lý nước thải bị nhiễm kim loại nặng Chủ nhiệm đề tài Trần Thị Kim Anh III Luan van INFORMATION ON RESEARCH RESULTS General information: Project title: Heavy metal removal from plating wastewater by pellet reactor Code number: T2018-35TĐ Coordinator: Tran Thi Kim Anh Implementing institution: Hochiminh City University of Technology and Education Duration: from 03/2018 to 03/2019 Objective(s): Hardness and heavy metal removal by pellet reactor by conducting a series of exeperiments such as: pH, flow rate (detention time), seeding material Creativeness and innovativeness: Heavy metal removal with high efficiency and compact model of pellet reactor, less footprint, capital cost and operational cost Research results: The pellet reactor has feasibility of hardness and heavy metal removal These results inferred that pellet reactor would be low-cost operational reactor to remove heavy metal from wastewater with the hardness removal efficiency up to 80% when influent concentration of 200 ppm and 90% with heavy metal removal when influent concentration of 40 ppm Products: Scientific report Lab-scale pellet reactor Effects, transfer alternatives of reserach results and applicability: Pellet reactor model is suitable for heavy metal removal from wastewater IV Luan van MỞ ĐẦU I Tổng quan nghiên cứu ngồi nước Q trình kết tủa phương pháp phổ biến để xử lý kim loại nặng từ nước thải công nghiệp Tuy nhiên, phương pháp có vài nhược điểm địi hỏi diện tích lớn, tách nước q trình xử lý bùn, kỹ trình vận hành nhiều bể phản ứng (Zhou et al., 1999) Phương pháp bể phản ứng tầng sôi (fluidized pellet reactor or pellet reactor) vuợt qua trở ngại trình vận hành với tải trọng thuỷ lực cao dẫn đến bể phản ứng nhỏ, chi phí vận hành thấp, khơng tạo bùn thải tái sử dụng Bể phản ứng tầng sơi chứng hiệu cao trình loại bỏ độ cứng (canxi) từ nước uống (Mahvi et al., 2005), ví dụ, loại bỏ độ cứng 99% canxi Driefontein (Giesen cộng sự, 2009), thu hồi phosphate (Montastruc et al., 2003), loại bỏ fluoride kim loại (Zhou et al., 1999, Aldaco et al., 2005) việc thu hồi kim loại nặng từ nước thải (Guillard Lewis, 2002) Zhou et al (1999) thấy với bể phản ứng tầng sôi hoạt động độ pH tối ưu, loại bỏ kim loại hiệu đạt 9295% tùy thuộc vào nồng độ ban đầu Mahvi et al (2005) nhận xét Bể phản ứng tầng sơi có nhiều thuận lợi: kích thước nhỏ, có thời gian phản ứng thấp, không tạo chất thải, xử lý tái sử dụng hạt pellet Gần đây, Procorp Enterprises LLC báo cáo Bể phản ứng tầng sơi loại bỏ chất ô nhiễm từ dòng đậm đặc RO tăng tỉ lệ thu hồi nâng cao hiệu RO lên 90% Ở Việt Nam, việc ứng dụng xử lý nước cứng kim loại nặng tập trung vào phương pháp thông thường kết tủa bể phản ứng bể lắng, phương pháp hấp phụ với dung lượng hấp phụ cực đại vật liệu vỏ chuối biến tính:121,95 mg Pb2+/g 53,2 mg Cu2+/g; rơm biến tính là: 55,56 mg Pb2+/g 46,3 mg Cu2+/g (Giang Huy, 2016) II Tính cấp thiết Trong năm gần đây, Việt Nam với phát triển kinh tế gia tăng dân số nên môi trường nước ngày bị ô nhiễm kim loại nặng chủ yếu bắt nguồn từ công nghiệp giao thơng vận tải Rất khó để loại bỏ kim loại nặng biện pháp xử lý Luan van Luan van Luan van Luan van Luan van VIETNAM ACADEMY OF SCIENCE AND TECHNOLOGY Vietnam Journal of Chemistry, Volume 56, Number 4e - 2018 TABLE OF CONTENTS Page Preface Design and synthesis of betulin derived 2-aminobenzamides Dinh Thi Cuc, Le Nhat Thuy Giang, Nguyen Thi Hien, Vu Ngoc Doan, Nguyen Tuan Anh, Hoang Thi Phuong, Luc Quang Tan, Dang Thi Tuyet Anh, Nguyen Van Tuyen Catalytic conversion of cellulose to 5-hydroxymethylfurfural (5-HMF) over SO42 ZrO2/SBA15 solid acid catalyst Pham Tung Son, Le Ha Giang, Nguyen Ba Manh, Pham Thi Thu Trang, Le Thanh Son, Vu Anh Tuan Study on the effect of graphene and ctab surfactant on the characteristics of natural rubber 10 Luong Nhu Hai, Nguyen Thi Ngoan, Le Thi Thuy Hang, Ngo Trinh Tung Preparation and characterization alginate/oligoalginates of nanocomposites of hydroxyapatite and 16 Nguyen Thi Hanh, Phan Thi Ngoc Bich Study on synthesis and cytotoxicity of the hybrid compound from betulin-maleic anhydridezidovudine 22 Nguyen Thi Hien, Dinh Thi Cuc, Vu Ngoc Doan, Dang Thi Tuyet Anh, Nguyen Van Tuyen Preparation and characterization of lycopene nanoparticles for pharmaceutical applications 27 Ho Thi Oanh, Dang Thi Tuyet Anh, Nguyen Van Tuyen, Duong Thi Hai Yen, Hac Thi Nhung, Nguyen Duc Tuyen, Pham Xuan Manh, Pham Duy Linh, Pham Thi Ha Anh, Hoang Mai Ha Phenolics from the roots of Ficus hirta 32 Dao Duc Thien, Tran Duc Dai, Nguyen Thi Thanh Huong, Vu Thi Huong, Nguyen Hoang Sa, Trinh Thi Thuy, Nguyen Thi Hoang Anh, Tran Duc Quan, Nguyen Thanh Tam Synthesis and inhibition of α-glucosidase by dammarane and oleanane triterpen a-ring fused pyrazole and isoxazole derivatives 36 Anastasiya V Petrova, Elmira F Khusnutdinova, Oxana B Kazakova, Nguyen Thi Thu Ha, Tran Thi Phuong Thao, Tran Van Loc, Nguyen Thi Dung, Irina E Smirnova Synthesis and antitumor activity of new vinca alkaloids from 3'-cyanoanhydrovinblastine 41 Vo Ngoc Binh, Nguyen Le Anh, Nguyen Thuy Hang, Tran Thi Yen, Ngo Quoc Anh 10 Effects of boehmite nanofillers on properties of natural rubber prepared by latex mixing technology 46 Pham Tung Son, Tran Thi Thanh Hop, Dang Thi Mai, Luong Nhu Hai, Ngo Trinh Tung 11 Hardness removal by crystallization in pellet reactor: a new approach for softening Hoang Thi Tuyet Nhung, Nguyen Khanh Lam, Tran Thi Kim Anh Luan van 51 12 Preparation of mesoporous SBA-15 and SBA-15/TiO2 nanotubes composite using Vietnam commercial sodium silicate for efficient photocatalytic removal of 2,4-dichlorophenoxyacetic acid herbicide (2,4-D) in aqueous solution 56 Nguyen Dinh Tuyen, Nguyen Thi Thu An, Dang Huu Canh, Nguyen Dinh Chung, Pham Thai Hung, Nguyen Quyet Tien, Ngo Van Quang, Truong Thi Thanh Nga, Hoang Hiep, Jaromir Jivkovsky, Hana Bibova, Lenka Hykrdova, Martin Kormunda 13 Effect of epoxidized linseed oil on the mechanical, morphological and rheological properties of poly(lactic acid) film 62 Trinh Duc Cong, Tran Vu Thang, Nguyen Van Khoi, Hoang Thi Phuong, Nguyen Thi Thuc, Ngo Thi Hang 14 Simultaneous determination of 18 polycylic aromatic hydrocarbons in instant noodles by gas chromatography tandem mass spectrometry 68 Dao Hai Yen, Tran Lam Thanh Thien, Dinh Thi Cuc, Nguyen Thi Kim Lien, Mai Thi Huyen Thuong, Le Truong Giang 15 Non-uniform sampling - a new technique for NMR measurement 74 Dang Vu Luong, Nguyen Quang Tam, Do Thi Thanh Xuan, Nguyen Tien Tai 16 Evaluation of anaerobic biodegradability of oxidized and unoxidized polyethylene (PE) films containing pro-oxidant additives in soil incubation media 78 Pham Thu Trang, Nguyen Thanh Tung, Nguyen Van Khoi, Nguyen Trung Duc, Pham Thi Thu Ha 17 Self-assembly of a sonicate graphite-ZnBi2O4 composite with enhanced visible light photocatalytic degradation of rhodamine B 83 Nguyen Thi Mai Tho, Dang Nguyen Nha Khanh, Nguyen Thanh Tien, Vu Quang Huy, Nguyen Quoc Thang, Do Trung Sy, Nguyen Thi Phuong Dieu, Nguyen Thi Kim Phuong 18 Structure, gelling property and antioxidant activity of polysaccharide extracted from red seaweed Gracilaria heteroclada 91 Quanh Thi Minh Thu, Do Thi Thanh Xuan, Ban Van Huynh, Dang Vu Luong, Ngo Van Quang, Ho Duc Cuong, Tran Thi Thanh Van, Thanh Thi Thu Thuy 19 Phytochemical constituents of n-hexane extract from the leaves of Markhamia stipulata var Canaense V.S Dang 96 Ngo Trong Nghia, Nguyen Nu Dan Phuong, Pham Nguyen Kim Tuyen, Ngo Quoc Luan, Phan Nhat Minh, Bui Trong Dat, Tran Cong Luan, Mai Dinh Tri, Nguyen Tan Phat 20 Flavonoids and iridoid from the leaves of Stereospermum binhchauensis V.S Dang 100 Ngo Trong Nghia, Truong Ngoc Bao Hien, Phan Nhat Minh, Le Tien Dung, Dang Van Son, Tran Cong Luan, Mai Dinh Tri, Nguyen Tan Phat 21 Characterization of PANi-MnO2 composite synthesized by cyclic voltammetry method 104 Mai Thi Thanh Thuy, Mai Thi Xuan, Nguyen Thi Van Anh 22 Effect of polyethylene graft maleic anhydride compatibilizer on flame retardant additives dispersion and properties of polyethylene composition 109 Hoang Huong, Tran Vu Thang, Nguyen Phi Trung, Nguyen Van Khoi, Hoang Thi Phuong, Trinh Duc Cong, Nguyen Van Manh 23 Study on electrochemical properties of Ti/TiO2-PANi-CNTs composite electrode in brewery wastewater containing glucose Nguyen The Duyen, Mai Thi Xuan, Mai Thi Thanh Thuy Luan van 115 24 Quercetin derivatives from the ethyl acetate extract of the leaves of Sterculia foetida Linn (Sterculiaceae) 120 Pham Dinh Thuong, Doan Tran Duy Cuong, Nguyen Tan Phat, Mai Dinh Tri, Pham Nguyen Kim Tuyen, Nguyen Kim Phi Phung 25 Manufacture pencil electrode modified with platinum nanoparticles applicable to analyse of the trace concentration of Pb (II) 124 Nguyen Thi Lieu, Cao Van Hoang, Pham Thi Hai Yen, Le Truong Giang 26 A study of NMR spectroscopy on an industrial polymeric MDI mixture used in rigid PU foam production 130 Nguyen Thi Hieu Ha 27 Effect elimination of organic compounds by electrolysis to enhance the electrochemical signal of Hg(II) determination using two-component self-assembled thin layer modified the composition glassy carbon electrode 136 Dang Thanh Huyen, Vu Duc Loi, Vu Thi Thu Ha, Pham Hong Phong 28 Simple and sensitive square wave adsorptive stripping voltammetric determination of atorvastatin using graphite pencil electrode 141 Pham Thi Hai Yen, Nguyen Hoang Anh, Nguyen Thi Lieu, Vu Thi Thu Ha 29 Effect of flow rate on arsenic removal by potentiostatic electrocoagulation method through electrochemical cell 147 Nguyen Hong Duc, Phan Thi Binh, Mai Thi Thanh Thuy, Nguyen Thi Van Anh, Mai Thi Xuan, Dinh Thi Huyen 30 Synthesis, characterization and photocatalytic performance of TiO2/graphene photocatalysts synthesized by hydrothermal method 153 Le Thi Thanh Lieu, Le Thi Thanh Hiep, Le Truong Giang, Vo Vien 31 Flavonoid and phenylethanoid glycosides from Leonurus heterophyllus 159 Tran Thi Hong Hanh, Pham Thi Cham, Do Hoang Anh, Pham Thi Mai Huong, Nguyen Xuan Cuong, Tran Hong Quang, Nguyen Hoai Nam 32 Study on rate of the UV absorbent additives for low density polyethylene (LDPE) 164 Nguyen Thi Minh Phuong, Nguyen Phi Trung, Nguyen Van Khoi, Tran Vu Thang, Trinh Duc Cong, Hoang Thi Phuong 33 Synthesis and investigate the electrochemical performance of Si/Graphene nanocomposite anode for Lithium-ion batteries 168 Nguyen Van Thang, Nguyen Manh Tuong, Nguyen Tran Hung 34 Phenothiazine derivative as organic photocatalyst for metal free atom transfer radical polymerization of methacrylate monomer 172 Tran Minh Hoan, Phan Tan Ngoc Lan, Nguyen Huu Tam, Nguyen Thi Le Thu, Nguyen Tran Ha 35 Accumulation and speciation of arsenic, cadmium and lead in liver and muscle tissues of freshwater fish Nguyen Quoc Thang, Dang Nguyen Nha Khanh, Le Van Tan, Do Trung Sy, Hoang Ngoc Lin, Nguyen Thi Phuong Dieu, Nguyen Thi Kim Phuong Luan van 178 36 Synthesis and cytotoxicity evaluation of novel substituted triazole–erlotinib hybrid compounds 184 Le Nhat Thuy Giang, Dinh Thuy Van, Dang Thi Tuyet Anh, Hoang Thi Phuong, Nguyen Thi Nga, Nguyen Van Tuyen 37 Targeting cancer cells with betulinic acid derived 2-aminobenzamide and hydroxamic 188 Dinh Thi Cuc, Nguyen Thi Hien, Vu Ngoc Doan, Le Nhat Thuy Giang, Hoang Thi Phuong, Vu Duc Cuong, Dang Thi Tuyet Anh, Nguyen Van Tuyen 38 Ergostane steroids from the fruiting bodies of Amauroderma subresinosum 192 Ha Manh Tuan, Nguyen Thi Luyen, Nguyen Hai Dang, Duong Thu Trang, Nguyen Thu Minh, Nguyen Duy Khanh, Nguyen Duy Cong, Ha Thi Van Anh, Nguyen Tien Dat 39 Secondary metabolites from marine Actinomycete Streptomyces sp A290 198 Vu Van Nam, Doan Thi Mai Huong, Do Thi Quynh, Chau Van Minh, Vu Thi Quyen, Le Thi Hong Minh, Pham Van Cuong 40 Secondary metabolites from Micromonospora sp G244 203 Cao Duc Danh, Truong Bich Ngan, Doan Thi Mai Huong, Tran Dang Thach, Le Thi Hong Minh, Nguyen Mai Anh, Chau Van Minh, Pham Van Cuong 41 Some results of study on modification of carbon nanotube surface 208 Part 1: Alkylation and oxidation of CNT surface Pham Cong Nguyen, Chu Anh Van, Luong Nhu Hai, Do Quang Minh, Vuong Quoc Tuan, Tran Huu Huy, Le Hong Hai, Do Quang Khang 42 Green synthesis of Ag/Ag2O@TiO2 nanotube composite photocatalysts using fresh tea leaf extracts for efficient solar degradation of insecticide chlorpyrifos ethyl residues in tea plants cultivation 214 Nguyen Dinh Chung, Dang Huu Canh, Nguyen Thi Thu An, Nguyen Quyet Tien, Ngo Van Quang, Nguyen Ngoc Tuan, Nguyen Quang An, Hoang Mai Ha, Nguyen Duc Tuyen, Ho Thi Oanh, Duong Thi Hai Yen, Hac Thi Nhung, Nguyen Dinh Tuyen 43 Valorization of microagale-derived mineral ash via composite fabrication with poly(vinyl alcohol) 220 Do Thi Cam Van, Le Truong Giang, Tran Dang Thuan 44 Inhibitory effect of Helicteres hirsuta loureiro aqueous leaves extract on α-glucosidase enzyme and lipid peroxidation in mice liver 226 Nguyen Thi Thu Ha, Le Thi Hai Yen, Nguyen Thanh Tra, Ba Thi Cham, Le Thi Tu Anh 45 Synthesis of MIL-53(Fe) for drug delivery purpose 230 Nguyen Thi Hoai Phuong 46 The synthesis and characteristics of a pyrocellulose from acacia cellulose 235 Doan Minh Khai, Phan Duc Nhan, Trinh Dac Hoanh 47 Intergrated system for domestic wastewater treatment: soil purification and anaerobic/aerobic biological processes Dao Hai Yen, Tran Dang Thuan, Le Truong Giang 240 48 Removal of Cu2+ and Pb2+ from aqueous solution using tea waste–derived activated carbon: experimental, kinetic, and thermodynamic 245 Tran Van Thuan, Pham Van Thinh, Bach Long Giang, Nguyen Dai Hai, Le Thi Hong Nhan, Tran Huu Quang, Nguyen Duy Trinh, Hoang Thi Bich, Do Trung Sy Luan van 49 Quantitative structure-activity relationship analyses to elucidate 2D-molecular descriptors of (R)-3-amidinophenylalanine inhibitors contributing to their inhibition constants with trypsin enzyme 251 Hoang Minh Hao, Phan Dang Quoi Tu, Pham Thi Bich Van 50 Electrochemical characteristic of the sulfate solution in the formation of the Ni-CeO2-CuO composite plating 258 Mai Van Phuoc, Nguyen Duc Hung 51 Optimization of hydrolysis conditions of shrimp head by-products by bromelain enzyme using response surface methodology and chemical characteristic of protein hydrolysates 264 Tran Thi Y Nhi, Nguyen Kim Thanh, Lai Thi Thuy, Le Thi Thanh Ha, Pham Thi Bich Hanh, Do Truong Thien 52 Preparation of graphene nanoplatelets by thermal shock in combination with probe-type sonication Nguyen Thi Nhiem, Tran Quang Vinh, Do Van Cuong, Doan Thi Hai, Truong Thi Hanh, Le Thi Hoai Nam Luan van 269 VIETNAM JOURNAL OF CHEMISTRY 56(4e) 51-55 SEPTEMBER 2018 Hardness removal by crystallization in pellet reactor: a new approach for softening Hoang Thi Tuyet Nhung, Nguyen Khanh Lam, Tran Thi Kim Anh * Faculty of Chemical and Food Technology, Ho Chi Minh City University of Technical Education Received 18 June 2018; Accepted for publication 25 August 2018 Abstract A pellet reactor was investigated to remove the hardness from supply water Pellet Reactor (PR) is a fluidized bed reactor, in which the removal of metal by crystallization process occurs in a fluidized bed using sand as seeding material With the molar ration CO32-/Ca2+ of 1.2, superficial velocity of 35.29 m/h, the diameter of sand of 0.1 mm, mass of sand of 90 g, the calcium removal efficiency in the PR could reach the highest with 96 % of Ca2+ removal The calcium carbonate pellets were analyzed the ingredient by X-Ray and the surface by SEM microphotography to get the morphological observation of the pellets The effectiveness in removing calcium from water of this study showed that the pellet reactor could treat the hardness in water with low cost and high efficiency Keywords Calcium hardness; pellet reactor; softening; sand; crystallization INTRODUCTION media size, mass of media, concentration of feed calcium and pH on calcium hardness removal efficiency were studied In addition, the surface of pellets was examined by X-Ray and SEM microphotography to get the morphological observation One of the popular methods for hardness removal from water and industrial wastewater is a chemical precipitation process However, it has some inherent limitations such as requiring a large area, a sludge dewatering facility, skillful operators and multiple basin configuration.[1] New process – pellet rector (PR) for hardness removal has been concerned in recent year with the foremost advantage of the decrease in sludge formation because of its product of dry pellets instead of wet sludge.[2] Crystallization process in pellet reactor (PR) has been used in many water and wastewater treatment applications, especially in water softening,[3,4] fluoride removal,[5,6,7] and heavy metal recovery from wastewater.[8,9] In pellet reactor, crystallization occurs on surface of seeding materials (mostly used silica sand) The fluidized bed is obtained by an upward flow of the inlet water at a suitable superficial velocity After operation, more calcium carbonate are covered on seeding material leading the bigger size, having a higher sedimentation velocity, will be extracted at the reactor bottom Although fluidized bed reactor has been proven a feasible process for softening and heavy metal removal, further detailed study of the process is needed to understand more by optimizing all the possible parameters effecting on the hardness removal efficiency In this study, the effect of (CO32−)/(Ca2+) molar ratio, superficial velocity, MATERIAL AND METHODS 2.1 Materials The synthetic feed water considered in this investigation was obtained prepared by adding CaCl2.2H2O (China) into supply water to get the calcium concentration of 550 mg/L Sodium carbonate (Na2CO3 H2O) (China) was used as an agent of crystallization reaction to inject to the pellet reactor by peristaltic pumps TRIWIN 8800-2004 and Labor-Schlauchpumpe PLP 66 2.2 Pellet reactor Hardness removal experiments were performed using a lab-scale pellet reactor The reactor for softening is columnar with conical reactors on the top of columnar, 200 mm height and a diameter of 20 mm (Fig 1), using garnet sand The water was pumped vertically upwards through the fluidized bed without recirculation with superficial velocity ranging from 35.29 to 54.11 At the same time, a mixture of Na2CO3 with a flow rate of L/h was 51 Luan van VJC, 56(4e) 2018 Tran Thi Kim Anh et al injected at a point cm away from the bottom of the pellet reactor to adjust the operational conditions as given in table Every run of experiment was operated hours continuously Samples of the effluent were taken at 60 intervals, and the value of efficiency is the average of times taking sample Calcium hardness was determined Samples was by EDTA using Titrimetric Method (2340C Standard Method) The surface morphology of pellets was examined by using Scanning electron microscopy (SEM, JEOL JMS-7410F, Japan) Pellets removed from the reactor before and after the different experiments were washed with Milli-Q deionized water, dried at 105 oC for h and analyzed by X-ray diffraction (Rikagu, CuKα) to determine the type of calcium carbonate on the pellets Fresh pellet Influent Na2CO3 Influent Figure Table 1: Operational conditions SV m/h 35.29 35.29-74.11 35.29 35.29 35.29 [CO32-]:[Ca2+] 1.0-1.3 1.2 1.2 1.2 1.2 Sand size, mm 0.2 0.2 0.1-0.6 0.1 0.1 RESULTS AND DISCUSSION [Ca2+], mgCaCO3 /l 550 550 550 550 200 - 1200 Sand mass, g 50 50 50 30 -150 90 equilibrium of reaction (2) to the right hand side, releasing protons and leading to a pH decrease [10] In Fig.2, calcium removal efficiency in batch mode is higher than in pellet reactor; therefore, pH out of batch mode is lower than in pellet reactor 3.1 Effect of [CO32−]/[Ca2+] molar ratio on hardness removal efficiency The effect of [CO32−]/[Ca2+] molar ratio was carried out to determine the suitable ratio required for optimal calcium hardness removal efficiency by Na2CO3 solution (Fig 2) As the theory, [CO32−]/ [Ca2+] = is enough to get 100 % efficiency However, the hardness removal efficiency of batch experiment (BE) and pellet reactor (PR) were only 89 % and 85 %, respectively, corresponding to 61 and 82 mg CaCO3/L of residual calcium hardness Higher efficiency in batch mode is due to the low contact time HRT = minutes in continuous mode in the pellet reactor with flow rate of 7.2 L/h The increase in [CO32-]/[Ca2+] was consequently observed to improve the hardness removal efficiency With higher CO32- concentration, higher supersaturation develops, which in turn gives rise to fast primary nucleation Nevertheless, when the ratio of [CO32-]/[Ca2+] was higher than 1.2, the hardness removal efficiency seem to be constant as depicted in Fig The efficiency of hardness removal was highest of 90.16 % at the molar ratio of CO32-/Ca2+ = 1.2 Similarly, when the precipitation of calcium carbonate occurs by reaction (1), the removal of the CO32- ion from supersaturated solution shifts the 14 Calcium Hardness removal efficiencies, % 100 12 95 10 90 pH out Run 85 80 1.05 1.1 1.15 1.2 1.25 1.3 [CO32−]/[nCa2+] Calcium hardness removal - BE Calcium hardness removal -PR pH out - BE pH out - PR Fig 2: Effect of [CO32−]/[Ca2+) ratio on calcium hardness removal efficiencies with 550 mgCaCO3/L of inlet Calcium hardness (HRT = minutes) Ca2+ + CO32-  CaCO3 (1) HCO3-  H+ + CO32- (2) This phenomenon was also observed in,[1] when the molar ratio of carbonate to metal increased from 52 Luan van VJC, 56(4e) 2018 Hardness removal by crystallization… 1.5/1 to 4/1, the efficiency of heavy metal removal increased, however, when the ratio continued to increased, the efficiency tended to decrease due to discrete precipitation leading to higher effluent heavy metal concentration be kept to ensure the bed expansion (< 59.1 m/h), but avoid pellet washing out of PR.[9] 3.2 Effect of superficial velocity on hardness removal efficiency Fig presents the effect of sand sizes in pellet reactor on calcium removal efficiency at a superficial velocity of 35.29 m/h It is observed that the crystal growth of the pellets of calcium carbonate depended on the size of the seeding material (Fig 4) Calcium hardness removal is a result of the crystallization of CaCO3 onto the sand Crystallization consists of four steps,[11] but nucleation and growth are two important stages Ripening and recrystallization are not significant for softening in PR Nucleation is the formation of new crystals, and growth is the increase in crystal size by deposition of individual ions, atoms, or molecules.[12] The smaller the granular size, the more quantity of sand More nuclei (sand) in fluidized bed promoted the crystallization of calcium carbonate pellets This led to the higher the calcium removal efficiency and the lower suspended solid in treated water However, with sand sizes less than 0.3 mm, residual calcium hardness as well as suspended solid were not much different among sand size of 0.1mm, 0.2 mm and 0.3 mm While they strongly increased with increasing sand sizes from 0.3-0.6 mm 3.3 Effect of sand size and sand mass on hardness removal efficiency 290 80 270 75 150 250 45 55 65 Superficial velocity, m/h 75 0.2 30 0.2 0.3 0.4 0.5 0.6 330 Sand sizes, mm 310 Fig 4: Influence of the particle size of the seed material on Calcium Hardness removal of pellet reactor 270 (b) As aforementioned, when seeding mass increased in the PR leading more places for nucleation, the efficiency of calcium removal also increased When sand mass increased from 30 to 150 g, the residual calcium concentration of the effluent decreased from 88 to 24 mg/L; however, the sand mass increased more, there was a slight decrease in calcium removal efficiency (Fig 5) This is due to with same superficial velocity but higher sand mass 250 45 55 65 Superficial velocity, m/h 0.4 60 290 35 0.6 90 0.1 Suspended solid Bed expended, % 0.8 120 (a) 70 Suspended solid Residual Calcium Hardness Suspended Solid, mg/L 85 35 Suspended solid, mg/L 310 Calcium Hardness, mgCaCO3/L 90 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 180 330 Calcium hardness… Bed expended, % Bed expended, % 95 Bed expended,% Calcium Hardness removal efficiencies, % The calcium removal efficiency decreased with the increase in superficial velocity from 35.29 to 74.11 m/h (corresponding, hydraulic retention time (HRT) decreased from 3.06 to 1.46 min) As the superficial velocity increased, the percentage of expanded bed (the height of sand layer before and after water pumped) raised from 252 % to 299 % Due to the porosity of the expended bed increased, the available surface area of the seed material per reactor volume was decreased.[7] This led to reduction in the efficiency of the hardness removal process from 91.2 % to 78.5 % Furthermore, when the superficial velocity increased, the process efficiency of PR reduced since HRT decreased This problem is clearly presented when superficial velocity increased from 59.1 to 64.4 m/h, the incomplete reaction of Ca2+ and CO32- on the sand lead to fine CaCO3 precipitate washing out of PR, resulting in strongly decreasing the efficiency of hardness removal, increasing the number of suspended solid in treated water Therefore, high superficial velocity needs to 75 Fig 3: Influence of the superficial velocity on calcium hardness removal efficiencies (a) and suspended solid concentration of the effluent (b) 53 Luan van VJC, 56(4e) 2018 Tran Thi Kim Anh et al 100 11.4 Residual Ca2+ pH 100 11.2 80 11 60 10.8 10.6 40 10.4 20 10.2 11 98 10.8 96 94 10.6 pH 11.6 Calcium Hardness removal efficiencies, % 120 developed, thus the precipitation efficiency increased This is also discussed in case of increasing molar ratio of [CO32-]/[Ca2+] pH Calcium Hardness, mgCaCO3/L the fluidized bed could not be expanded leading to less contacting surface area, decreasing the nucleation potential 92 Calcium Hardness removal efficiencies, % pH 90 88 86 84 200 10 30 60 90 Sand mass, g 120 400 600 800 1000 10.4 10.2 10 1200 Inlet Calcium Hardness, mgCaCO3/L 150 Fig 6: Influence of the particle size of the seed material on Calcium Hardness removal of pellet reactor Fig 5: Influence of the particle size of the seed material on Calcium Hardness removal of pellet reactor 3.5 Microscopic analyses The surface of pellets after and before shows the difference color It is clear that since CaCO3 precipitated and covered on the surface of the sand, therefore, the color of used pellet is whiter Fig shows SEM microphotographs of the pellets from the crystallization process when sand is used as seeding material With SEM, there were changes in the morphology of the pellets during the experiments: some precipitates appeared on the sand 3.4 Effect of hardness concentration on removal efficiency Fig shows the effect of calcium concentration on the calcium removal efficiency When increasing the calcium concentration in the influent from 200 mg/l to 600 mg/L, we see that the efficiency increases fast from 86 to 96 % but slightly increased when the Calcium concentration went up to 1200 mg/L With higher concentration, higher supersaturation b ) a ) Fig 7: SEM (x 5000) microphotography of (a) sands and (b) pellets of calcium carbonate on sands Pellets before and after the precipitation experiments were analyzed with XRD to investigate the species of calcium carbonate deposited on the pellet In Fig 8, a difference between the profile of original sand and the profile of a pellet after an experiment was observed With the original pellet, no peak at calcium carbonate at the angles 2θ of 29.5o and 36o was detected but with the used pellet, the peak had higher intensity This confirmed that calcium carbonate precipitated on the surface of Table 2: Minerals deposited on the pellet after experiment Minerals CaCO3 Ca[Fe(II),Mg](CO3)2 Ca.Mg(CO3)2 54 Luan van Θ value 23, 29.5, 31, 36, 39.5, 43, 47.5, 48.5, 56.5, 57.5, 60.5, 63, 64.5, 65.5, 70 31 33, 35, 37.7, 41, 45, 60 VJC, 56(4e) 2018 Hardness removal by crystallization… 33(8), 1918-1924 Gerard van Houwelingen, Rick Bond, Tom Seacord & Eric Fessler Experiences with pellet reactor softening as pretreatment for inland desalination in the USA, Desalination and Water Treatment, 2010, 13(1-3), 259-266 A Graveland, J C Can Dijk, P J., De Moel and J H C M Oomen Developments in water softening by means of pellet reactors, 1983, 75(12), 619-625 Van Houwelingen G A., Nooijen W Water softening by crystallization recovers its costs, European Water Pollution Control, 1993, 3(4), 33-35 Van den Broeck K., van Hoornick N., van Hoeymissen J.V., de Boer R., Giesen A., Wilms, D Sustainable treatment of HF wastewaters from semiconductor industry with a fluidized bed reactor, IEEE Transactions on Semiconductor Manufacturing, 2003, 3, 423-428 Aldaco, R., Garea, A., Irabien, A Fluoride recovery in a fluidized bed: crystallization of calcium fluoride on silica sand, Industrial and Engineering Chemistry Research, 2006a, 45(2), 796-802 Aldaco R., Garea A Irabien A Modeling of particle growth: application to water treatment in a fluidized bed reactor, Proceedings of the XVII International Conference on Chemical Reactors, Athens, Greece, 2006b Costodes V C., Lewis A E Reactive crystallization of nickel hydroxycarbonate in fluidized-bed reactor: fines production and column design, Chemical Engineering Science, 2006, 61(5), 1377-1385 Tai C Y., Chen P.C., Tsao T M Growth kinetics of CaF2 in a pH-stat fluidized-bed crystallizer, Journal of Crystal Growth, 2006, 290, 576-584 10 Lide D R Handbook of Chemistry and Physics, 88th ed., CRC Press, Boca Raton, FL, USA, 2008 11 Lieser, K H Steps in precipitation reactions Angewandte Chemie International Edition, 1969, 8, 188-202 12 Willard D Harms, Jr and R Bruce Robinson Softening by fluidized bed crystallizers, Journal of Environmental Engineering, 1992, 118(4), 513 pellet Table also shows the kinds of minerals appeared on the surface of pellet after experiment which was Calcite, Ankerite and Dolomite CPS 800 700 600 500 400 Pellets after experiments 300 200 Pellets before experiments 100 10 20 30 40 θ 50 60 70 80 Fig 8: XRD diffraction diagrams for the pellets before and after experiments CONCLUSION A feasible method was proposed to remove calcium from water by a pellet reactor A pellet reactor was used to precipitate the calcium carbonate on the garnet sand The removal efficiency of calcium was up to 96 % at an inlet concentration of calcium of 600-1200 mgCaCO3/l; [CO32-]/[Ca2+] molar ratio of 1.2 and a superficial velocity of 35.29 m/h The efficiency increased as the inlet calcium concentration, [CO32-]/[Ca2+] molar ratio increased, the sand size and the flow rate decreased The species of calcium carbonate deposited on the pellet were Calcite, Ankerite and Dolomite REFERENCES Ping Zhou, Ju-Chang Huang, Alfred W FLi, Shirly Wei Heavy metal removal from wastewater in fluidized bed reactor, Water Research, 1999, Corresponding author: Tran Thi Kim Anh Ho Chi Minh University of Technology and Education 01, Vo Van Ngan, Linh Chieu ward, Thu Duc district, Ho Chi Minh City, Viet Nam E-mail: anhttk@hcmute.edu.vn; Telephone: +84- 1265050934 55 Luan van S K L 0 Luan van ... kim loại nặng trước thải vào mơi trường Do đó, việc xử lý nước thải nguồn để thu hồi kim loại, tạo hội tuần hoàn lại nước giảm hàm lượng kim loại thải dòng thải trước đưa vào trạm xử lý nước thải. .. TÀI KH&CN CẤP TRƯỜNG TRỌNG ĐIỂM NGHIÊN CỨU XỬ LÝ NƯỚC KIM LOẠI NẶNG TRONG NƯỚC THẢI XI MẠ BẰNG PELLET REACTOR Mã số: T2018-35TĐ Chủ nhiệm đề tài: TS Trần Thị Kim Anh Thành viên đề tài: TS Hoàng... TÀI KH&CN CẤP TRƯỜNG TRỌNG ĐIỂM NGHIÊN CỨU XỬ LÝ NƯỚC KIM LOẠI NẶNG TRONG NƯỚC THẢI XI MẠ BẰNG PELLET REACTOR Mã số: T2018-35TĐ Chủ nhiệm đề tài: TS Trần Thị Kim Anh TP HCM, 04/2019 Luan van