Heavy metals are the most dangerous substances in the environment, have caused deleterious effect not only to the environment but also to the public’s health. Different studies have demonstrated that plants have a high removal capacity for lead ions from pollution sources. However, these plant species were rather limited. Thus, the project aimed to find out plant species that represent its lead removal ability to reduce environmental pollution. The experiment was carried out factorially as a randomized complete design in hydroponic systems with four treatments (0, 100, 200, and 300 mg/l of Pb) and three replications. The results indicated that the growth of the Dracaena sanderiana plant is well in Pb concentration of 100 mg/l, with less growth while the increasing lead concentration of 200 mg/l and 300 mg/l. The amount of lead in the water of three treatments 100 mg/l, 200 mg/l, and 300 mg/l after 30 days of the experiment decreased by 91.5%, 86.8%, and 86.4%, respectively. It was found that Dracaena sanderiana exhibited high lead treatment efficiency in the water. Moreover, results showed that the accumulation of lead in the roots of Dracaena sanderiana is quite large with treatments of 100 mg/l, 200 mg/l, and 300 mg/l lead concentrations were 5073.8 mg/kg, 5134.0 mg/kg, 7054.0 mg/kg, respectively. In contrast, the ability to lead accumulation in plant leaves and stems is lower. cultivated in hydroponic systems with four treatments and three replications. Four levels of Pb(NO3)2 (0, 100, 200, and 300 ppm) were used. The monitoring indicators include the contents of lead in water, the growth target of Dracaena sanderiana, and the accumulation of lead contents in different organs of Dracaena sanderiana. The results indicated that: the growth of the Dracaena sanderiana plant is well in Pb concentration of 100 ppm, with less growth while the increasing lead concentration of 200 ppm and 300 ppm. The amount of lead in the water of three treatments 100 ppm, 200 ppm, and 300 ppm after 30 days of the experiment decreased by 91.5%, 86.8%, and 86.4%, respectively. It was found that Dracaena sanderiana exhibited high lead treatment efficiency in the water. Moreover, results show that the accumulation of lead in the roots of Dracaena sanderiana is quite large with treatments of 100 ppm, 200 ppm, and 300 ppm lead concentrations were 5073.8 mg/kg, 5134.0 mg/kg, 7054.0 mg/kg, respectively. In contrast, the ability to lead accumulation in plant leaves and stems is much lower.

Research and assessment of sludge management in Thu Dau Mot wastewater treatment enterprise. The composition of the sludge depends on the composition of the wastewater, the wastewater treatment process and the sludge treatment process. The most common non-toxic organic compounds include materials of plant and animal origin such as proteins, amino acids, sugars, fats ... compounds containing N, P... Toxic organic compounds include compounds of PHA (Poly-nuclear aromatic hydrocarbons), alkyl phenols, polychlorinated biphenyls (PSBs) organochlorine pesticides, phenols, chloro-benzenes ... Heavy metals such as: Zn, Pb, Cu, Cd, Ni, Cr, Hg, As… (in the range from 1ppm to 100ppm). Some of these compounds can be toxic to humans and animals. Therefore, it is necessary to control the concentration of heavy metals in the sludge before disposal or reuse. Harmful microorganisms such as pathogenic bacteria, viruses and protozoa together with parasitic helminths can increase the potential harm to human, animal and plant health. Inorganic compounds such as silicates, aluminates, calcium and magnesium compounds.

Environmental issues such as the wastewater have influenced each aspect of our lives. For human and environmental health protection, it is necessary to remove excess zinc in industrial wastewaters before discharging them to environment. Modified diatomite displayed larger surface area and pore volumes in comparison with untreated natural diatomite, which favored heavy metals sorption behavior. In this study, the removal of Zn(II) ions from aqueous solution was studied using Fe/Mn modified diatomite sample at different adsorption parameters such as contact initial metal ions concentration, dosage of Fe/Mn-Diatomite and ionic strength Na2CO3 on ionic Zn2+ adsorption capacity of diatomite modified. The residual zinc concentration in the solution was determined using flame atomic absorption spectroscopy. The results showed that: the gravitational increase increases with increasing time and then becomes almost stable, with 120 minutes timeliness; absorption increases when Fe/Mn-Ditomite is increased, absorption reaches 89.48% at a dose of 1.5 g/l; additional different concentrations Na2CO3 ranged from 0 ppm to 80 ppm the results showed that performance treatment Zn2+ of correspond 94,85%. This study could lay an essential foundation to develop modified diatomite for heavy metal removal from wastewater.

Study on sampling sludge from 04 industrial parks in Binh Duong province such as My Phuoc, Dong An, Viet Huong 1, Song Than 2 to analyze the pollution criteria to assess the pollution possibility of industrial waste sludge. The research results show that: at present, the total volume of sludge generated today in the industrial park fluctuates about 4,450 – 6,255 kg/day, equivalent to dry sludge volume is 1,035.725 – 1,532.11 kg/day. The estimated volume of dry sludge generated from industrial parks in the future from 2019 to 2020 ranges from 30,023 to 31,396 kg/day. Most sludge from 04 wastewater treatment plants hadn’t heavy metals (Hg, Pb, Cu, Ni, Cr, Zn, Cd), especially Dong An Industrial park Treatment plant had Zn, value 49.7 – 49.9 mg/l. The sludge from the wastewater treatment plants of 04 industrial parks had amount of helminth eggs that exceeds the USEPA's regulations on pathogens (type A sludge).

Investigation of the possibility of treating wastewater containing Cu2+ heavy metal with activated carbon material prepared from macadamia husk with activating K2CO3 in Optimal conditions such as temperature 6500C and burning time is 60 minutes. Survey results show that coal with the ability to handle heavy metals is best at 84.02% in optimal conditions such as pH=5 and time. Baking is 30 minutes. The results show similarities with other research results and are applicable to wastewater treatment Cu2+.

Investigate the possibility of treating wastewater containing heavy metals Zn2+ with activated carbon material prepared from macadamia shell with chemical activating agent H3PO4, showing high efficiency of adsorption of Zn2+. The results of the study showed that activated carbon with H3PO4 activating agent has high adsorption capacity, capable of handling Zn2+ best at pH = 4.5, dosage 1.8 g/L and time is 120 minutes. . The results show similarities with other research results and are capable of treating wastewater containing heavy metals Zn2+.