Advanced Materials Research Vol. 800

Abstract: Trivalent chrome has an abroad application in the area of leather tanning, electrolytic plating and dyeing due to the strong capability of coordination. Pollution caused by chrome salts cannot be ignored. This paper proved that the chrome tanning wastewater can be treatment by chrome chelates (CRBD). The supernatant was reused in washing and pickling process and chromium sludge was utilized to make regeneration chrome-tanning agents; which all not only protect the environment but also save production cost. A series of experiment results showed that SO₄^2-and oil contents increased slightly as well as Cl^- content decreased when the tanning wastewater recycled several times. The total chrome content was up but the influence evaluated by the finish leather was not evident. Items of wet-blue leather and finish leather were tested such as shrinkage temperature, Cr₂O₃ in the leather, softness, fullness and so on. In the meantime, the physical and mechanical properties of the finish leather were not less than the common tanning method. Besides, the leather rate significantly increased when the regenerative chrome-tanning agent was used on retanning process.

Abstract: Adsorption removal of arsenic from contaminated drinking water was carried out by using Mn-Fe binary oxide adsorbent. Main phase of adsorbents was influenced by pH value of solution, and pH of 10 is the suitable synthesis condition to achieve the Mn-Fe binary oxide suspension adsorbents. Adsorbents with Mn/Fe mole ratio from 6/4 to 2/8 exhibits higher arsenite removal larger than 99.6%.

Abstract: The initial pH, initial concentration of Fe²⁺ and NaClO on the degradation of ammonium butyl-dithiophosphate using Fe²⁺/NaClO process have been investigated in this paper. The results shows that under the optimum reaction conditions of a temperature 28°C, pH 4.0, the initial concentration of Fe²⁺ and NaClO is 15 mg/L and 5.33 mL/L, respectively, about 87.86% ammonium butyl-dithiophosphate removal can be achieved within 150 min by using a Fe²⁺/NaClO process. The degradation of ammonium butyl-dithiophosphate under different NaClO concentration conditions follows the first order exponential decay equations. The Fe²⁺/NaClO can efficiently oxidation of ammonium butyl-dithiophosphate in aqueous solution and can be an effective process for the treatment of ammonium butyl-dithiophosphate wastewater.

Abstract: The polysulfone membranes surface modification by the low temperature air plasma for the study. The PS membranes surface composition, filtration, antifouling characteristics with the modification was characterized by water contact angle, water fluxes, interception rate. Polysulfone membranes hydrophilic has been greatly improved, by water contact angle decreased significantly with low temperature air plasma treatment .Optimal conditions for plasma processing are power 60W, 1.5min, vacuum 60Pa.The water fluxes for the modified PS were increased 2.3 times than the nascent one, the interception rate was little changed. Membrane pollution gradually increased as the wastewater permeation flux decreased with time.

Abstract: Solar biogas digester and wetland-pond system treated the wastewater for the rural about 60 families. The system comprised a solar anaerobic baffle digester, an anaerobic filter, a subsurface vertical flow wetland, and an eco pond. The four units were connected in series. The solar digester and the filter produced enough biogas evenly in whole year and provided 80-91% total suspended solids (TSS) removal. The wetland-pond developed aquatic crops, fisheries and waterfowl aquaculture. In this artificial ecosystem, bacterial oxidization, algae photosynthesis and food web degradation greatly reduced COD, BOD₅, TN, NH4-N, TP, and pH of water.

Abstract: Adsorption treatment test was carried out using powder activated carbon (PAC for short) and coconut shell activated carbon (SAC for short) taking water contaminated by military agent as the object of study in order to study on the influences of type, dosage, adsorption time, pH value and initial solution concentration of adsorbent on adsorption effect and to discuss about adsorption mechanisms of activated carbon.