Laundry Wastewater Research Articles

Treatment Rate Improvement of the Ozone Oxidation Method for Laundry Waste Water.

Treatment Rate Improvement of the Ozone Oxidation Method for Laundry Waste Water.

Activated carbon filter treatment of laundry waste water in nuclear power plants and filter recovery by heating in vacuum

Abstract Laundry waste water including such organic compounds as surfactants is generated from washing workers’ clothes in nuclear power plants. An activated carbon filter (ACF) to remove them for water purification and vacuum heating (VH) treatment for the spent ACF recovery were studied. For the purification test, 2×10−2 m3 of simulated waste water (SWW) were circulated in an experimental apparatus at 1.5×10−3 m3/min, passing through the ACF (0.205×1.2 m) roll continuously, until total organic carbon (TOC) concentration was lowered from 100 ppm to 10 ppm. To measure TOC, 1×10−5 m3 of SWW were sampled every 10 min. After that, the ACF roll was removed and treated by VH at 800°C for 2 h. Then, the second allotment of SWW was introduced. The purification test was started again to check the VH effect. The dependence of ACF adsorption rate and amount adsorbed, on the recovery number was checked. It took about 5 h to lower TOC. This adsorption performance was recovered by VH treatment. The dependence of ACF adsorption rate on the recovery number peaked at 10 times, and then dropped gradually. In contrast, the adsorption amount of organic compounds was simply lowered. This was attributed to the effect of macropore length reduction being transiently larger than the influence of the specific surface area lowering.

Method for treating radioactive laundry waste water : Izumida Tatsuo; Kikkawa Ryozo; Tsuchiya Hiroyuki; Kiuchi Yoshimasa; Hattori Yasuo IA: Hitachinaka, Japan assigned to Hitachi Ltd; Hitachi Engineering & Services Co Ltd Hitachi Nuclear Engineering Co Ltd

Method for treating radioactive laundry waste water : Izumida Tatsuo; Kikkawa Ryozo; Tsuchiya Hiroyuki; Kiuchi Yoshimasa; Hattori Yasuo IA: Hitachinaka, Japan assigned to Hitachi Ltd; Hitachi Engineering & Services Co Ltd Hitachi Nuclear Engineering Co Ltd

Compatibility of the Ultraviolet Light-Ozone System for Laundry Waste Water Treatment in Nuclear Power Plants

As an alternative treatment system for laundry waste water in nuclear power plants, a system was chosen in which such organic compounds as surfactant would be oxidized by ultraviolet (UV) light and ozone. The system compatibility, UV light source, and dissolved ozone concentration were examined through experiments. First, ozone gas was absorbed in the waste water. After the dissolved ozone concentration equilibrated at the desired value, the waste water was irradiated by a mercury lamp. Then, the time dependence of the concentrations of the organic compounds, the dissolved ozone, and the hydrogen peroxide were measured to estimate the treatment rate of the system. The mercury lamp with a 105-Pa vapor pressure achieved large UV radiation and a treatment rate increase, leading to a compatible system without secondary waste generation. The effect of the dissolved ozone concentration on the treatment rate was saturated when concentration was >3.3 × 10-4 mol/10-3 m3 at the time UV radiation was started. Numerical results indicated the saturation was due to hydrogen peroxide generation, which prevents hydroxyl radical generation.

5556535 Filtration system for recycling water used in a car wash : Van Der Est N Ambacht, Netherlands assigned to Micro Tec B V

Combined biological and physicochemical process was selected for treatment of laundry wastewater. The results show that after microbial adaptation, almost 91% of COD was removed at food to microorganism (F/M) ratio of 0.12 gBOD/gMLSS·d. Dehydrogenase activity of the biomass showed an increasing trend and finally reached 3.8 μgTFgbiomass.d corresponding to the highest process performance. 16SrRNA fragment and phylogenetic analysis identified Pseudomonas pharmacofabricae and Bacillus spp. as the dominant bacteria. The effluent of the biological process was then injected into the UV/O3 process for complete removal of residual COD and detergent. Finally, microfiltration and ultrafiltration were used to remove any remaining suspended solids. The operating cost analysis showed that 0.65 €/m3 treated wastewater is required for treatment of the laundry wastewater. Accordingly, the suggested combination of the biological and physicochemical process could be a promising and highly efficient process for treatment and reuse of laundry wastewater.

Aquatic risk assessment of a polycarboxylate dispersant polymer used in laundry detergents.

Polycarboxylates enhance detergent soil removal properties and prevent encrustation of calcium salts on fabrics during washing. Laundry wastewater typically reaches wastewater treatment plants, which then discharge into aquatic environments. The yearly average concentration of a 4500 molecular weight (MW) sodium acrylate homopolymer reaching U.S. wastewater treatment plants will be approximately 0.7 mg/L. Publications showing the low to moderate acute aquatic toxicity of polycarboxylates are readily available. However, there are no published evaluations that estimate wastewater removal and characterize the probability of exceedance of acceptable chronic aquatic exposure. WW-TREAT can be used to estimate removal during wastewater treatment and PG-GRIDS can be applied to characterize risk for exceedance in wastewater treatment plant outfalls. After adjustments for the MW distribution of the homopolymer, WW-TREAT predicted that 6.5% will be removed in primary treatment plants and 60% will be removed in combined primary and activated sludge treatment plants. These estimates are consistent with wastewater fate tests, but underestimate homopolymer removal when homopolymer precipitation is included. Acceptable levels of chronic outfall (receiving water) exposure were based on aquatic toxicity testing in algae, fish, and Daphnia magna. PG-GRIDS predicted that no unreasonable risk for exceedance of acceptable chronic exposure will occur in the outfalls of U.S. wastewater plants. Future development of wastewater treatment models should consider polymer MW distribution and precipitation as factors that may alter removal of materials from wastewater.

Investigations of the origin of PCDD/F in municipal sewage sludge

The contributions of surface runoff and houshold wastewater to the PCDD/F levels in sewage sludge were investigated. The PCDD/F homologue patterns in household wastewater and laundry wastewater were very similar to those in sewage sludge and in sewer sediments from the wastewater-system in Bayreuth (FRG), whereas the patterns in surface runoff and sewage sludge were different. A crude mass balance indicated that 2–7 times more of the PCDD/F in sewage sludge originates from households than from runoff. These results suggest that the importance of household wastewater as a PCDD/F source has been underestimated.

Lagoons and ponds

Lagoons and ponds

Sorption of Ammonium‐Ions by Clinoptilolite and by Strongly Acidic Cation Exchangers

AbstractThe sorption capacity of two natural sorbents of different origin and of Wofatit KPS is determined by dynamic laboratory investigations and the influence of a thermal pretreatment of clinoptilolite, of the type and quantity of regenerants and of the presence of other cations is investigated. There are represented results of the ammonia removal from biologically treated municipal wastewater and of the removal of caesium‐ions from laundry wastewaters. The capacity of clinoptilolite is lower than that of the ion‐exchange resin, but clinoptilolite has the advantage of a considerably higher affinity for ammonium‐ions, so that it can be used also in the presence of other salts in water to be treated. The ammonium concentration should not exceed 30 mg/l, in order to avoid too short filter runs.

Aboral depressions in the tests of the sea urchin Tripneustes cf. gratilla (L.) in the Gulf of Eilat, Red Sea

Flattening and aboral depressions occurred in high proportions in Tripneustes cf. gratilla (L.) populations that inhabited an artificial lagoon in the northern Gulf of Eilat, Red Sea. The average test height to diameter ( H D ) ratio of the most affected population, near a small wastewater outlet, was 0.43 ± 0.01 (Se) and 76% showed aboral depressions. The H D ratio was 0.54 ± 0.01 in populations outside the lagoon and <1% exhibited aboral depressions. The exposure of normal T. cf. gratilla to industrial CaCO 3 precipitation inhibitors affected the growth and H D ratio in a similar manner within 30–45 days. The light-weight tests of the deformed urchins and the occurrence of skeletal resorption in the interior part of the test indicate that the unknown pollutant, possibly contained in laundry wastewater, reduced calcification by these animals and resulted in a mechanical collapse of the tests. A regular pattern of small pits at the aboral tip of the ambulacra suggests that intestinal mesenterial threads, attached to the test at the same points from within, facilitated this collapse by a mechanical pull. The normal test morphology of the regular echinoids may be regulated by the mechanical activity of various contractile and elastic tissue elements, among which mesenterial threads are probably included.

Effects of laundry wastewater on benthic algae in ditches in the Netherlands

A modified, artificial substrate method was used to study the effects of laundry wastewater on benthic algae in a polder in the western part of the Netherlands. In a polluted ditch a clear chemical gradient was found with regard to the parameters conductivity, B.O.D., C.O.D., NH4, ortho-P, total-P and Cl, showing decreasing values with increasing distance from the polluting source. pH and oxygen values showed the opposite. Algae, such asEuglena viridis, Nitzschia palea andOscillatoria spp. were positively correlated with the amount of pollution, while others, such asChrysochaete brittannica, Chrysophaera gallica, Cocconeis placentula andSynedra ulna showed a negative correlation with the amount of pollution. The results of algal counts are evaluated by means of diffenent methods,e.g. similarity coefficients, species abundance curves, diversity and saprobity indices. In different seasons benthic algal biomass proved to be a good indicator of pollution, except very close to the polluting source. The role of algal periodicity, influencing species composition, diversity and saprobity values, and biomass growth, has been discussed. The need of revising the saprobity system for stagnant ditches in the Netherlands, using artificial substrates, has been stressed.

長良川のLAS (MBAS) とリン

The pollution of river by laundry wastewater and the main sources of orthophosphate ion in Nagara river water were studied.Rivers in the Nôbi plain were undoubtedly polluted by laundry wastewater, and their MBAS concentration increased from the upper to the lower reaches.The greater part of soluble phosphorus compounds in Nagara river water was orthophosphate. The soluble orthophosphate P concentration in the river was not markedly affected by the phosphorus from laundry wastewater.On the other hand, the correlation coefficient of concentration between soluble orthophosphate P and urea N was 0.385 and the correlation of P with N was significant on 5 % of significant level. In the period of rice plant cultivation, one of the main sources of orthophosphate ion and urea in the Nagara river water was outflow from plowland on which manure and organophosphorus agricultural chemicals has been spread, in the river's drainage area; another was the effluent from raw sewage treatment plants in the river basin. But in winter and spring, it seemed that the two constituents in the river were chiefly supplied by domestic miscellaneous wastewater and the effluent mentioned above.

The separation of shower and laundry wastewater using Zr-PAA R.O. membranes

This paper describes the reverse osmosis tests which were carried out on shower and laundry wastewater using dynamically formed zirconium oxide - polyacrylate membranes which were formed in situ. Performance data consisting of solute rejection and product water flux, as depending on several operating parameters, are presented. These parameters are : operating pressure with the range 8 × 105 N/m2 to 7 × 106N/m2, temperature with the range 76°C to 93°C, circulation velocity with the range 1.7 m/sec to 8.2 m/sec, and feed concentration ranging from normal to 14 times normal. Data presented include rejections of organic material (TOC), ammonia, urea, and several ionic species.