Abstract: Water body with various turbidity has some mitigating effect in treating emergent heavy metal contamination in drainage basin. In this experiment, turbidity was used as indicator to study the influence of turbidity ranging 50 NTU~650 NTU (Nephelometric Turbidity Unit) on the removal of heavy metals (cadmium, lead, and arsenic) at room temperature (25 ℃) and low temperature (5 ℃). Results suggested that sediment had the best removal effect on lead, followed by cadmium and arsenic in sequence, among which the removal rate of lead amounted to 99%. Turbidity was in a linear relationship with the highest concentration of heavy metal that could be treated to be meeting standard after treatment. At room temperature, the correlation coefficients of the highest concentration of cadmium, lead, and arsenic against turbidity were 0.996, 0.998 and 0.999 respectively, whereas at low temperature, the coefficients were 0.998, 0.996 and 0.998 respectively. Compared with low temperature, room temperature is more conducive to the removal of heavy metals cadmium, lead, and arsenic by sediment. Also at room temperature, heavy metals of high concentrations can be removed to meet the sanitary standards of drinking water.

Key words: turbidity, adsorption, cadmium, lead, arsenic, sediment, heavy metal contamination, removal rate